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Sample records for automatic tld reader

  1. Next Generation Model 8800 Automatic TLD Reader

    International Nuclear Information System (INIS)

    Velbeck, K.J.; Streetz, K.L.; Rotunda, J.E.

    1999-01-01

    BICRON NE has developed an advanced version of the Model 8800 Automatic TLD Reader. Improvements in the reader include a Windows NT TM -based operating system and a Pentium microprocessor for the host controller, a servo-controlled transport, a VGA display, mouse control, and modular assembly. This high capacity reader will automatically read fourteen hundred TLD Cards in one loading. Up to four elements in a card can be heated without mechanical contact, using hot nitrogen gas. Improvements in performance include an increased throughput rate and more precise card positioning. Operation is simplified through easy-to-read Windows-type screens. Glow curves are displayed graphically along with light intensity, temperature, and channel scaling. Maintenance and diagnostic aids are included for easier troubleshooting. A click of a mouse will command actions that are displayed in easy-to-understand English words. Available options include an internal 90 Sr irradiator, automatic TLD calibration, and two different extremity monitoring modes. Results from testing include reproducibility, reader stability, linearity, detection threshold, residue, primary power supply voltage and frequency, transient voltage, drop testing, and light leakage. (author)

  2. Development and evaluation of new semi-automatic TLD reader software

    International Nuclear Information System (INIS)

    Pathan, M.S.; Pradhan, S.M.; Palani Selvam, T.; Datta, D.

    2018-01-01

    Nowadays, all technology advancement is primarily focused on creating the user-friendly environment while operating any machine, also minimizing the human errors by automation of procedures. In the present study development and evaluation of new software for semi-automatic TLD badge reader (TLDBR-7B) is presented. The software provides an interactive interface and is compatible with latest windows OS as well as USB mode of data communication. Important new features of the software are automatic glow curve analysis for identifying any abnormality, event log register, user defined limits on TL count and time of temperature stabilization for readout interruption and auto reading resumption options

  3. Microcomputer control of automated TLD reader

    International Nuclear Information System (INIS)

    Bjarland, Bert.

    1979-10-01

    The interfacing electronics, the control algorithms and the developed programs of a 6800 microcomputer controlled automated TLD reader are described. The TL reading system is implemented with a photomultiplier tube and a charge-to-pulse converter. The gain of the TL reading system is controlled through the use of a temperature compensated LED reference light source. Automatic compensation of PM tube dark current is optional. The short term stability of TL readings is better than 3 %. (author)

  4. N2 gas station and gas distribution system for TLD personnel monitoring gas based semi-automatic badge readers

    International Nuclear Information System (INIS)

    Chourasiya, G.; Pradhan, S.M.; Kher, R.K.; Bhatt, B.C

    2003-01-01

    Full text: New improvised hot gas based Auto TLD badge reader has several advantages over the earlier contact heating based manual badge reader. It requires constant supply of N 2 gas for its operation; The gas supplied using replaceable individual gas cylinders may have some safety hazards in their handling. It was therefore considered worthwhile to setup a N 2 gas assembly/ station outside the lab area and to bring regulated gas supply through network of tubes with proper regulation to the individual readers. The paper presents detailed description of the gas station and distribution system. The system is quite useful and offers several practical advantages for readout of TLD badges on the semiautomatic badge readers based on gas heating. Important advantage from dosimetric point of view is avoidance of gas flow rate fluctuations and corresponding variations in TL readouts

  5. A new fully automated TLD badge reader

    International Nuclear Information System (INIS)

    Kannan, S.; Ratna, P.; Kulkarni, M.S.

    2003-01-01

    At present personnel monitoring in India is being carried out using a number of manual and semiautomatic TLD badge Readers and the BARC TL dosimeter badge designed during 1970. Of late the manual TLD badge readers are almost completely replaced by semiautomatic readers with a number of performance improvements like use of hot gas heating to reduce the readout time considerably. PC based design with storage of glow curve for every dosimeter, on-line dose computation and printout of dose reports, etc. However the semiautomatic system suffers from the lack of a machine readable ID code on the badge and the physical design of the dosimeter card not readily compatible for automation. This paper describes a fully automated TLD badge Reader developed in the RSS Division, using a new TLD badge with machine readable ID code. The new PC based reader has a built-in reader for reading the ID code, in the form of an array of holes, on the dosimeter card. The reader has a number of self-diagnostic features to ensure a high degree of reliability. (author)

  6. Improvements of RGD3 TLD reader

    International Nuclear Information System (INIS)

    Zhao Jianxing; Wang Jiaqi; Li Yuanfang; Wu Furong; Xiao Wuyun

    1999-01-01

    The author summarized the main features of the improved RGD3 TLD reader. Through a large number of experiments some persuasive data are obtained, which show that an remarkable improvement has been achieved, especially in its stability to the standard illuminates, data dispersivity, and effectiveness to glow curves analysis. Working with the newly developed data processing software, the comprehensive performance of the whole system will be enhanced greatly

  7. How to diagnose any type of TLD Reader?; Como diagnosticar cualquier tipo de TLD Reader?

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Manuel Lopez; Garcia, Jose A. Tamayo; Gil, Alex Vergara; Lores, Stefan Gutierrez; Acosta, Andry Romero; Villanueva, Gilberto Alonso, E-mail: manolo@cphr.edu.cu, E-mail: jotag@cphr.edu.cu, E-mail: alex@cphr.edu.cu, E-mail: stefan@cphr.edu.cu, E-mail: andy@cphr.edu.cu, E-mail: gilberto@cphr.edu.cu [Centro de Proteccion e Higiene de las Radiaciones (CPHR), La Habana (Cuba)

    2013-07-01

    The acquisition of know how of practical experiences obtained in the repair and maintenance of readers TLD RADOS for five years of work and the request by the International Atomic Energy for signing new Research Contracts (CRP), made possible the CRP 13328, in which the specialist is committed in the course of a year, to deliver educational software in order to train personnel associated with the operation of the TLD readers RADOS. Due to the importance of continuous transfer of knowledge for new generations of technicians and specialists who join our laboratories, the idea came when the first interactive CD that grouped 19 videos, divided into three blocks was ready: learning, repair and maintenance; it was suggested to expand the training for any TLD reader. Thus a much more complete than the first version package emerged. 7 cases were subsequently published in an IAEA TECDOC, 1599 were included.

  8. How to diagnose any type of TLD Reader?

    International Nuclear Information System (INIS)

    Rodriguez, Manuel Lopez; Garcia, Jose A. Tamayo; Gil, Alex Vergara; Lores, Stefan Gutierrez; Acosta, Andry Romero; Villanueva, Gilberto Alonso

    2013-01-01

    The acquisition of know how of practical experiences obtained in the repair and maintenance of readers TLD RADOS for five years of work and the request by the International Atomic Energy for signing new Research Contracts (CRP), made possible the CRP 13328, in which the specialist is committed in the course of a year, to deliver educational software in order to train personnel associated with the operation of the TLD readers RADOS. Due to the importance of continuous transfer of knowledge for new generations of technicians and specialists who join our laboratories, the idea came when the first interactive CD that grouped 19 videos, divided into three blocks was ready: learning, repair and maintenance; it was suggested to expand the training for any TLD reader. Thus a much more complete than the first version package emerged. 7 cases were subsequently published in an IAEA TECDOC, 1599 were included

  9. Environmental dose measurement with microprocessor based portable TLD reader

    International Nuclear Information System (INIS)

    Deme, S.; Apathy, I.; Feher, I.

    1996-01-01

    Application of TL method for environmental gamma-radiation dosimetry involves uncertainty caused by the dose collected during the transport from the point of annealing to the place of exposure and back to the place of evaluation. Should an accident occur read out is delayed due to the need to transport to a laboratory equipped with a TLD reader. A portable reader capable of reading out the TL dosemeter at the place of exposure ('in situ TLD reader') eliminates the above mentioned disadvantages. We have developed a microprocessor based portable TLD reader for monitoring environmental gamma-radiation doses and for on board reading out of doses on space stations. The first version of our portable, battery operated reader (named Pille - 'butterfly') was made at the beginning of the 80s. These devices used CaSO 4 bulb dosemeters and the evaluation technique was based on analogue timing circuits and analogue to digital conversion of the photomultiplier current with a read out precision of 1 μGy and a measuring range up to 10 Gy. The measured values were displayed and manually recorded. The version with an external power supply was used for space dosimetry as an onboard TLD reader

  10. Performance evaluation of vertical feed fully automated TLD badge reader using 0.8 and 0.4 mm teflon embedded CaSO4:Dy dosimeters

    International Nuclear Information System (INIS)

    Ratna, P.; More, Vinay; Kulkarni, M.S.

    2012-01-01

    The personnel monitoring of more than 80,000 radiation workers in India is at present carried out by semi-automated TLD badge Reader systems (TLDBR-7B) developed by Radiation Safety Systems Division, Bhabha Atomic Research Centre. More than 60 such reader systems are in use in all the personnel monitoring centers in the country. Radiation Safety Systems Division also developed the fully automated TLD badge reader based on a new TLD badge having built-in machine readable ID code (in the form of 16x3 hole pattern). This automated reader is designed with minimum of changes in the electronics and mechanical hardware in the semiautomatic version (TLDBR-7B) so that such semi-automatic readers can be easily upgraded to the fully automated versions by using the new TLD badge with ID code. The reader was capable of reading 50 TLD cards in 90 minutes. Based on the feedback from the users, a new model of frilly automated TLD badge Reader (model VEFFA-10) is designed which is an improved version of the previously reported fully Automated TLD badge reader. This VEFFA-10 PC based Reader incorporates vertical loading of TLD bards having machine readable ID code. In this new reader, a vertical rack, which can hold 100 such cards, is mounted from the right side of the reader system. The TLD card falls into the channel by gravity from where it is taken to the reading position by rack and pinion method. After the readout, the TLD card is dropped in a eject tray. The reader employs hot N 2 gas heating method and the gas flow is controlled by a specially designed digital gas flow meter on the front panel of the reader system. The system design is very compact and simple and card stuck up problem is totally eliminated in the reader system. The reader has a number of self-diagnostic features to ensure a high degree of reliability. This paper reports the performance evaluation of the Reader using 0.4 mm thick Teflon embedded CaSO 4 :Dy TLD cards instead of 0.8 mm cards

  11. A TLD reader for wide range in situ dose measurement

    International Nuclear Information System (INIS)

    Deme, S; Apathy, I.; Bodnar, L.; Csoeke, A.; Hejja, I.

    1998-01-01

    A portable thermoluminescent dosemeter reader suitable for reading at the site of exposure is described. The instrument consists of a glass bulb containing the CaSO 4 :Dy thermoluminescent material laminated to the surface of an electrically heated resistive metal plate. The bulb is encapsulated in a cylindrical, pen-like metal holder made of aluminium. A one-wire-port integrated electronic programmable memory chip mounted inside the holder contains the identification code and the individual calibration parameters of the dosemeter. The aperture of the holder is normally covered by a stainless steel tube to protect the bulb from light and mechanical shocks. The tube slips backwards automatically when the dosemeter is inserted into the reader. The system is used by the Hungarian nuclear power plant. (M.D.)

  12. Dosimetric properties of the 'Pille' portable, wide dose range TLD reader

    International Nuclear Information System (INIS)

    Szabo, P.P.; Feher, I.; Deme, S.; Szabo, B.; Vagvoelgyi, J.

    1986-01-01

    The dosimetric properties of a portable TLD reader are described. The TLD system named 'Pille' or 'moth' consists of a lightweight battery-operated portable TLD reader and its CaSO 4 :Dy bulb dosemeters. The reproducibility of the TLD system at constant temperature was found to be better than + -2%, and the mean time between failures exceeded 5 years. The dose range of the system is wide, covering more than 6 orders of magnitude, from 5 μGy to 10 Gy. The energy dependence of the CaSO 4 :Dy bulb dosemeters is less than + - 20% above 100 keV in the energy compensation capsules. Without additional annealing, the bulb dosemeters can be re-used at least 100 times, which is an important aspect during in situ measurements. (author)

  13. The design philosophy for an automatic TLD system to meet current international specifications

    International Nuclear Information System (INIS)

    Haaslahti, J.

    1986-01-01

    The object of this paper is to describe the elements of a new automatic TLD system intended to meet draft IEC/ISO proposals and ANSI requirements in the USA. Dosemeter badge design is based on ICRU recommendations. The basic intent has been to produce a standard system that can measure and file raw data that can be adapted to specific user requirements with software. The system consists of a programmable automatic reader, an automatic irradiator, a computer, and dosemeters for environmental, whole body, extremity, and clinical applications. The reader uses hot nitrogen heating and photon counting, and measurement conditions may be chosen with complete freedom. The reader can produce a real-time glow curve to assist in checking performance. The irradiator has a 90 Sr- 90 Y source to permit programmed irradiation for calibration and material sensitivity checks. Cassettes are used to hold TLD cards during processing. Cassette coding both identifies samples and calls measurement parameters into use from memory. The system can be preprogrammed to measure all common materials and all common dosemeter elements (both square and round). (author)

  14. Some dosimetric properties of the LiF:Mg,Ti evaluated by the automatic 6600 thermoluminescent reader

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Shachar, B; Weinstein, M; German, U [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

    1996-12-01

    Some dosimetric properties of the new LiF:Mg,Ti TLD cards were checked, when evaluated by the new automatic 6600 TLD reader. The cards were calibrated to a dose of 1.0 mGy by five identical irradiations, and the TL-dose response was measured for a range of 75 - 1100 mGy. A very high accuracy was found for the three kind of chips measured (TLD-100, TLD-700 and TLD-600) and a low minimum measurable dose (MMD) was found, too. There is a good fit between the analytical evaluation and the theoretical calculation of the MMD. The results obtained are much better than those of the LiF:Mg,Ti cards evaluated by the older automatic 2271 reader used in the last two decades (authors).

  15. PorTL - a compact, portable TLD reader for environmental and personal dosimetry

    International Nuclear Information System (INIS)

    Deme, S.; Apathy, I.; Bodnar, L.; Csoke, A.; Feher, I.; Pazmandi, T.

    2005-01-01

    Thermoluminescent dosimeters (TLDs) are commonly used for environmental monitoring, for personal and medical dosimetry, for dosimetry in nuclear facilities, etc. Major advantages are their independence of the power supply, small dimension, sensitivity, good stability, wide measuring range, resistance to environmental changes and relatively low cost. The disadvantage is that the detector must be transported for evaluation to a laboratory equipped with a large, heavy and expensive TLD Reader operated by qualified personnel, which considerably increases the costs and delays results. To overcome this disadvantage, the KFKI Atomic Energy Research Institute (KFKI AEKI), in co-operation with BL Electronics (Hungary), has developed a new and unique TLD system containing a small, portable, battery powered and moderate-price reader for commercial use. This paper gives a detailed description and parameters of this system.(author)

  16. Systematical and statistical errors in using reference light sources to calibrate TLD readers

    International Nuclear Information System (INIS)

    Burgkhardt, B.; Piesch, E.

    1981-01-01

    Three light sources, namely an NaI(Tl) scintillator + Ra, an NaI(Tl) scintillator + 14 C and a plastic scintillator + 14 C, were used during a period of 24 months for a daily check of two TLD readers: the Harshaw 2000 A + B and the Toledo 651. On the basis of light source measurements long-term changes and day-to-day fluctuations of the reader response were investigated. Systematical changes of the Toledo reader response of up to 6% during a working week are explained by nitrogen effects in the plastic scintillator light source. It was found that the temperature coefficient of the light source intensity was -0.05%/ 0 C for the plastic scintillator and -0.3%/ 0 C for the NaI(Tl) scintillator. The 210 Pb content in the Ra activated NaI(Tl) scintillator caused a time-dependent decrease in light source intensity of 3%/yr for the light source in the Harshaw reader. The internal light sources revealed a relative standard deviation of 0.5% for the Toledo reader and the Harshaw reader after respective reading times of 0.45 and 100 sec. (author)

  17. Automatic spent fuel ID number reader (I)

    International Nuclear Information System (INIS)

    Tanabe, S.; Kawamoto, H.; Fujimaki, K.; Kobe, A.

    1991-01-01

    An effective and efficient technique has been developed for facilitating identification works of LWR spent fuel stored in large scale spent fuel storage pools of such as processing plants. Experience shows that there are often difficulties in the implementation of operator's nuclear material accountancy and control works as well as safeguards inspections conducted on spent fuel assemblies stored in deep water pool. This paper reports that the technique is realized as an automatic spent fuel ID number reader system installed on fuel handling machine. The ID number reader system consists of an optical sub-system and an image processing sub-system. Thousands of spent fuel assemblies stored in under water open racks in each storage pool could be identified within relatively short time (e.g. within several hours) by using this combination. Various performance tests were carried out on image processing sub-system in 1990 using TV images obtained from different types of spent fuel assemblies stored in various storage pools of PWR and BWR power stations

  18. Analysis on the evaluation of dose of the team reader TLD SOLARO, post-adjustment of the heating resistance marks

    International Nuclear Information System (INIS)

    Morales C, M.

    2000-09-01

    This report describes the process carried out in the area of personal dosimetry as for different evaluations carried out in the team reader TLD SOLARO it marks, which evaluates chips of LiF and cards containing two pellets of LiF-700, to determine if after having carried out an adjustment in the heating system the dose evaluations they continue being acceptable, that is to say, the evaluated doses stay inside the error margin allowed for the case of external individual monitoring

  19. Results and discussion of laboratory experiences with different automated TLD readers for personnel monitoring

    International Nuclear Information System (INIS)

    Regulla, D.F.; Drexeler, G.

    Although the film seems to continue serving as the main personnel dosemeter in Germany for the time in sight, the evolution of particularly solid state techniques and their properties are thoroughly considered with respect to a possible generalized application in personnel monitoring. For this reason different automated TLD systems that are commercially available have been investigated in the laboratory in order to find out their usefulness for a largescale or also decentralized service. Along with studying the dosimetrical and apparative parameters, the question has been discussed to which monitoring philosophy these TLD systems seem to fit. It is reported both on experimental experiences achieved as well as on the results of basic discussions that in return influence the discussion about the necessary outfit of personnel TL dosemeters

  20. Analysis of glow curves of TL readouts of CaSO4:Dy teflon based TLD badge in semiautomatic TLD badge reader

    International Nuclear Information System (INIS)

    Pradhan, S.M.; Sneha, C.; Adtani, M.M.

    2010-01-01

    The facility of glow curve storage and recall provided in the reader software is helpful for manual screening of the glow curves; however no further analysis is possible due to absence of numerical TL data at the sampling intervals. In the present study glow curves are digitized by modifying the reader software and then normalized to make them independent of the dose. The normalized glow curves are then analyzed by dividing them into five equal parts on time scale. This method of analysis is used to correlate the variation of total TL counts of the three discs with time elapsed post irradiation

  1. What Automaticity Deficit? Activation of Lexical Information by Readers with Dyslexia in a Rapid Automatized Naming Stroop-Switch Task

    Science.gov (United States)

    Jones, Manon W.; Snowling, Margaret J.; Moll, Kristina

    2016-01-01

    Reading fluency is often predicted by rapid automatized naming (RAN) speed, which as the name implies, measures the automaticity with which familiar stimuli (e.g., letters) can be retrieved and named. Readers with dyslexia are considered to have less "automatized" access to lexical information, reflected in longer RAN times compared with…

  2. Reproducibility Test for Thermoluminescence Dosimeter (TLD) Using TLD Radpro

    International Nuclear Information System (INIS)

    Nur Khairunisa Zahidi; Ahmad Bazlie Abdul Kadir; Faizal Azrin Abdul Razalim

    2016-01-01

    Thermoluminescence dosimeters (TLD) as one type of dosimeter which are often used to substitute the film badge. Like a film badge, it is worn for a period of time and then must be processed to determine the dose received. This study was to test the reproducibility of TLD using Radpro reader. This study aimed to determine the dose obtained by TLD-100 chips when irradiated with Co-60 gamma source and to test the effectiveness of TLD Radpro reader as a machine to analyse the TLD. Ten chips of TLD -100 were irradiated using Eldorado machine with Co-60 source at a distance of 5 meters from the source with 2 mSv dose exposure. After the irradiation process, TLD-100 chips were read using the TLD Radpro reader. These steps will be repeated for nine times to obtain reproducibility coefficient, r i . The readings of dose obtained from experiment was almost equivalent to the actual dose. Results shows that the average value obtained for reproducibility coefficient, r i is 6.39 % which is less than 10 %. As conclusion, the dose obtained from experiment considered accurate because its value were almost equivalent to the actual dose and TLD Radpro was verified as a good reader to analyse the TLD. (author)

  3. A new TLD system for space research

    International Nuclear Information System (INIS)

    Feher, I.; Deme, S.; Szabo, B.; Vagvoelgyi, J.; Szabo, P.P.; Csoeke, A.; Ranky, M.; Akatov, Yu.A.

    1980-06-01

    A small, portable, vibration and shock resistant thermoluminescent dosemeter (TLD) system was developed to measure the cosmic radiation dose on board of a spacecraft. The TLD system consists of a special bulb dosemeter and a TLD reader. The measuring dose range of the TLD system is from 10 μGy up to 100 mGy. The TLD reader can operate on a battery; its electrical power consumption is about 5 W, its volume is about 1 dm 3 and its mass is about 1 kg. Details are given of the construction and technical parameters of the dosemeter and reader. (author)

  4. 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)

  5. A bar-code reader for an alpha-beta automatic counting system - FAG

    International Nuclear Information System (INIS)

    Levinson, S.; Shemesh, Y.; Ankry, N.; Assido, H.; German, U.; Peled, O.

    1996-01-01

    A bar-code laser system for sample number reading was integrated into the FAG Alpha-Beta automatic counting system. The sample identification by means of an attached bar-code label enables unmistakable and reliable attribution of results to the counted sample. Installation of the bar-code reader system required several modifications: Mechanical changes in the automatic sample changer, design and production of new sample holders, modification of the sample planchettes, changes in the electronic system, update of the operating software of the system (authors)

  6. A bar-code reader for an alpha-beta automatic counting system - FAG

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, S; Shemesh, Y; Ankry, N; Assido, H; German, U; Peled, O [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

    1996-12-01

    A bar-code laser system for sample number reading was integrated into the FAG Alpha-Beta automatic counting system. The sample identification by means of an attached bar-code label enables unmistakable and reliable attribution of results to the counted sample. Installation of the bar-code reader system required several modifications: Mechanical changes in the automatic sample changer, design and production of new sample holders, modification of the sample planchettes, changes in the electronic system, update of the operating software of the system (authors).

  7. New advanced TLD system for space dosimetry

    International Nuclear Information System (INIS)

    Feher, I.; Szabo, B.; Vagvoelgyi, J.; Deme, S.; Szabo, P.P.; Csoeke, A.

    1983-10-01

    A new version of the TLD reader type PILLE has been developed for space applications. The earlier compact and portable device could also be used for measurements during space flights but its range was limited. A new bulb detector with easier handling has also been developed with an upper limit of linear dose response of 10 Gy. The range of this new and more versatile reader, NA206S, (1μGy-10 Gy) is 3 orders of magnitude higher than that of the earlier system; it also has increased sensitivity and decreased mass. It can be used not only in space applications but also for environmental monitoring or even in accident dosimetry. The measured dose value is displayed on a four-digit display with automatic range switch. Another new version, the NA206E, has been developed for environmental dosimetry; it can be operated from a battery or from the mains. (author)

  8. Environmental monitoring with a portable TLD system

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, P P; Feher, I; Deme, S; Szabo, B; Vagvoelgyi, J; German, E [Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics

    1984-01-01

    Two types of TLD systems are used for environmental dose monitoring. One is based on an NHZ-203 laboratory TLD reader and CaSO/sub 4/:Dy powder. The other is based on CaSO/sub 4/:Tm bulbs and a small, portable TLD reader built into a cross-country car and operated by means of the car battery. The laboratory TLD system has been used for many years for environmental monitoring and it has been tested and proved satisfactory at international intercomparisons for environmental dosemeters. The new portable TLD system has the advantage of being able to establish the dose in a few minutes at the environmental station. The transport dose is omitted as the TLDs are evaluated at the field site. The evaluation of a bulb needs only a few minutes and the measured dose value can be reported back by radio - an important aspect during an emergency situation.

  9. The study of new calibration features in the Harshaw TLD system

    International Nuclear Information System (INIS)

    Luo, L. Z.

    2007-01-01

    The Harshaw TLD system has three key calibration procedures: the Reader, the Dosemeter and the Algorithm. These functions must be properly calibrated for the system to achieve the optimum results. For the conventional reader and dosemeter calibration, Harshaw TLD recommends a pre-fade and a post-fade of 24-48 h when calibrating the system for LiF:Mg,Ti type dosemeter. It is also recommended that keeping the fade time consistent is important to maintain the quality of the system performance. In recent years, new calibration features have been introduced into the Harshaw TLD models 6600 and 8800 operating systems. These new features are Auto Calibration, Auto QC and Auto Blank, and they give the user the ability to set up the clear-expose-read process to be performed automatically in a sequence for each dosemeter. This saves processing time and keeps the fade time the same. However, since the fade time is near zero, will it affect the TLD system calibration factors? What should the user expect? This paper presents a study of the effect of Auto Calibration/Auto QC to the TLD operation. (authors)

  10. Design, fabrication, installation and shielding integrity testing of source storage container for automatic source movement system used in TLD calibration facility

    International Nuclear Information System (INIS)

    Subramanian, V.; Baskar, S.; Annalakshmi, O.; Jose, M.T.; Jayshree, C.P.; Choudry, Shreelatha

    2012-01-01

    A state-of-art TLD laboratory has been commissioned in January 2000 at Radiological Safety Division of Indira Gandhi Centre for Atomic Research (IGCAR). The laboratory provides personnel monitoring service to 2000 occupational workers from Indira Gandhi Centre for Atomic Research and Bhabha Atomic Research Centre facilities. The laboratory has been accredited by the Radiation Safety Systems Division (RSSD), Bhabha Atomic Research Centre (BARC) since year 2002. The laboratory has exclusive facility for the calibration of the TLD cards. As apart of accreditation procedure and taking into account of geometry effect, the dose rate at the card position is determined by the accreditation authorities by using graphite chamber (secondary or national standard instrument) and often re estimated by a condenser R meter (M/s Victoreen, Germany) by our laboratory. As per the regulatory requirement, the exposure protocols should be automated. Towards this an automatic source movement system has been augmented in the calibration facility. By using the system, the source will be brought to the irradiation position by pneumatically and exposures will be terminated by counter, timer and triggering system. To accomplish this task a lead container has been designed, fabricated and mounted at the beneath of the calibration table for the storage of source. As per the automation process, a lead container for the source storage has been designed and installed beneath to the Calibration Table. The container was designed to hold a 3Ci 137 Cs source, but present activity of the source is 1.2Ci. Hence, the shielding integrity was tested with higher active source (1.7Ci 60 Co). The dose rate measured outside on the circumference of the container at the middle of the source is found to be the same as calculated using QAD CGGP calculations. The top plug is so designed to avoid inadvertent upward movement of the source. Though, the shielding was not adequate on top of the top plug, however it does

  11. Automated TLD system for gamma radiation monitoring

    International Nuclear Information System (INIS)

    Nyberg, P.C.; Ott, J.D.; Edmonds, C.M.; Hopper, J.L.

    1979-01-01

    A gamma radiation monitoring system utilizing a commercially available TLD reader and unique microcomputer control has been built to assess the external radiation exposure to the resident population near a nuclear weapons testing facility. Maximum use of the microcomputer was made to increase the efficiency of data acquisition, transmission, and preparation, and to reduce operational costs. The system was tested for conformance with an applicable national standard for TLD's used in environmental measurements

  12. Type tests to the automatic thermoluminescent dosimetry system acquired by the CPHR for personal dosimetry

    International Nuclear Information System (INIS)

    Molina P, D.; Pernas S, R.; Martinez G, A.

    2006-01-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF:Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  13. Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry

    International Nuclear Information System (INIS)

    Molina P, D.; Pernas S, R.

    2005-01-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF: Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  14. Microcomputer control of automated TL reader

    International Nuclear Information System (INIS)

    Bjarland, B.

    1980-01-01

    An automatic TL reader has been developed for use within a TLD based personal monitoring service. A 6800 based microcomputer is used for system control, operator communication, calibration and checking of reader operation, and for output of data. The dosimeter identity code is printed in human readable characters on the dosimeter card, and is read by using an optical character recognition unit. The code may include individual sensitivity correction coefficients for the TL chips on the card. The chips are heated with hot nitrogen gas and the thermoluminescence is recorded by a photomultiplier tube circuit, the gain and offset of which are continuously monitored and, when necessary, adjusted, to maintain calibration. The reader may operate in any of seven modes, i.e. reading modes for three types of dosimeters, semiautomatic modes for production of the three types of dosimeters, and a monitor mode. (Auth.)

  15. Automatic segmentation of myocardium at risk from contrast enhanced SSFP CMR: validation against expert readers and SPECT

    International Nuclear Information System (INIS)

    Tufvesson, Jane; Carlsson, Marcus; Aletras, Anthony H.; Engblom, Henrik; Deux, Jean-François; Koul, Sasha; Sörensson, Peder; Pernow, John; Atar, Dan; Erlinge, David; Arheden, Håkan; Heiberg, Einar

    2016-01-01

    Efficacy of reperfusion therapy can be assessed as myocardial salvage index (MSI) by determining the size of myocardium at risk (MaR) and myocardial infarction (MI), (MSI = 1-MI/MaR). Cardiovascular magnetic resonance (CMR) can be used to assess MI by late gadolinium enhancement (LGE) and MaR by either T2-weighted imaging or contrast enhanced SSFP (CE-SSFP). Automatic segmentation algorithms have been developed and validated for MI by LGE as well as for MaR by T2-weighted imaging. There are, however, no algorithms available for CE-SSFP. Therefore, the aim of this study was to develop and validate automatic segmentation of MaR in CE-SSFP. The automatic algorithm applies surface coil intensity correction and classifies myocardial intensities by Expectation Maximization to define a MaR region based on a priori regional criteria, and infarct region from LGE. Automatic segmentation was validated against manual delineation by expert readers in 183 patients with reperfused acute MI from two multi-center randomized clinical trials (RCT) (CHILL-MI and MITOCARE) and against myocardial perfusion SPECT in an additional set (n = 16). Endocardial and epicardial borders were manually delineated at end-diastole and end-systole. Manual delineation of MaR was used as reference and inter-observer variability was assessed for both manual delineation and automatic segmentation of MaR in a subset of patients (n = 15). MaR was expressed as percent of left ventricular mass (%LVM) and analyzed by bias (mean ± standard deviation). Regional agreement was analyzed by Dice Similarity Coefficient (DSC) (mean ± standard deviation). MaR assessed by manual and automatic segmentation were 36 ± 10 % and 37 ± 11 %LVM respectively with bias 1 ± 6 %LVM and regional agreement DSC 0.85 ± 0.08 (n = 183). MaR assessed by SPECT and CE-SSFP automatic segmentation were 27 ± 10 %LVM and 29 ± 7 %LVM respectively with bias 2 ± 7 %LVM. Inter-observer variability was 0 ± 3 %LVM for manual delineation and

  16. The study of new calibration features in the Harshaw TLD system

    International Nuclear Information System (INIS)

    Luo, L.Z.

    2005-01-01

    Full text: In the Harshaw TLD system, there are three key calibration procedures; the reader, the dosimeter and the algorithm. These procedures must be properly calibrated for the system to achieve the optimum results. For the conventional reader and dosimeter calibration, Harshaw recommends a pre-fade and a post-fade of 24 - 48 hours when calibrating the system. Harshaw also emphasizes that keeping the fade time consistent is important to maintain the quality of the system performance. In recent years, new calibration features have been introduced into the operating system. These new features are auto calibration, auto QC and auto blank, and they give the user the ability to set up the clear-expose-read performed automatically in a sequence for each dosimeter. This saves processing time and keeps the fade time the same. However, since the fade time is near zero, will it affect the TLD system calibration factors? What should the user expect? This paper presents a study of the effect of auto calibration / auto QC to the TLD operation. (author)

  17. Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Pernas S, R. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20, No. 4113 e/ 41 y 47, Miramar, Ciudad de la Habana (Cuba)]. e-mail: daniel@cphr.edu.cu

    2005-07-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF: Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  18. Type tests to the automatic thermoluminescent dosimetry system acquired by the CPHR for personal dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Pernas S, R.; Martinez G, A. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20 No. 4113 e/41 y 47. Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba)

    2006-07-01

    The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF:Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

  19. A Computerized QC Analysis of TLD Glow Curves for Personal Dosimetry Measurements Using Tag QC Program

    International Nuclear Information System (INIS)

    Primo, S.; Datz, H.; Dar, A.

    2014-01-01

    The External Dosimetry Lab (EDL) at the Radiation Safety Division at Soreq Nuclear Research Center (SNRC) is ISO 17025 certified and provides its services to approximately 13,000 users throughout the country from various sectors such as medical, industrial and academic. About 95% of the users are monitored monthly for X-rays, radiation using Thermoluminescence Dosimeter (TLD) cards that contain three LiF:Mg,Ti elements and the other users, who work also with thermal neutrons, use TLD cards that contain four LiF:Mg,Ti elements. All TLD cards are measured with the Thermo 8800pc reader. Suspicious TLD glow curve (GC) can cause wrong dose estimation so the EDL makes great efforts to ensure that each GC undergoes a careful QC procedure. The current QC procedure is performed manually and through a few steps using different softwares and databases in a long and complicated procedure: EDL staff needs to export all the results/GCs to be checked to an Excel file, followed by finding the suspicious GCs, which is done in a different program (WinREMS), According to the GC shapes (Figure 1 illustrates suitable and suspicious GC shapes) and the ratio between the elements result values, the inspecting technician corrects the data. The motivation for developing the new program is the complicated and time consuming process of our the manual procedure to the large amount of TLDs each month (13,000), similarly to other Dosimetry services that use computerized QC GC analysis. it is important to note that only ~25% of the results are above the EDL recorded level (0.10 mSv) and need to be inspected. Thus, the purpose of this paper is to describe a new program, TagQC, which allows a computerized QC GC analysis that identifies automatically, swiftly, and accurately suspicious TLD GC

  20. Estimation of uncertainty in TLD calibration

    International Nuclear Information System (INIS)

    Hasabelrasoul, H. A.

    2013-07-01

    In this study thermoluminescence dosimeter TLD was use of individual control devices to make sure the quality assurance and quality control in individual monitoring. The uncertainty measured in reader calibration coefficients for tow reader and uncertainty in radiation dose after irradiate in SSDL laboratory. Fifty sample was selected for the study was placed in the oven at a temperature of 400 for an hour to get zero or background and took zero count by or background and took zero count by reader (1) and reader (2) and then irradiate in SSDL by cesium-137 at a dose of 5 mGy and laid back in the oven at degrees 100 and degrees 10 minutes, to 10 chips for calibration and readout count by reader one and reader two. The RCF was found for each reader above 1.47 and 1.11, respectively, and found the uncertainty RCF was found for each reader above 1.47 and 1.11, respectively, and found the uncertainly RCF 0.430629 and 0.431973. Radiation dose was measured for fifty samples irradiate to dose of 5 mGy and read the count by reader 1 and reader 2 the uncertainty was found for each reader 0.490446 and 0.587602.(Author)

  1. Ten years experience with a large computerized TLD-personnel monitoring system

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1986-01-01

    It is now ten years since our Institute for Radiation Protection has fully replaced its filmdosimetry service by a computerized automated TLD system. Presently more than 13000 radiation workers are monthly monitored by three automated TLD readers linked to the computer center. The paper describes system hardware and software and experience gained in long-term routine operation. In particular the introduction of the new ICRU quantities for personnel dosimetry in the existing TLD system is discussed. (Author)

  2. TLD personnel monitoring dose estimation- extending the upper limit of the dose range

    International Nuclear Information System (INIS)

    Popli, K.L.; Sathian, Deepa; Divakaran, T.; Massand, O.P.

    2001-01-01

    TLD personnel monitoring was introduced in the year 1975 in India and at present nearly 41,000 radiation workers are being monitored by 13 monitoring laboratories all over India. The BARC- TLD being used for personnel monitoring is based on CaSO 4 :Dy embedded in PTFE and semi-automatic TL reader using hot N 2 Gas for heating the dosimeters. This reader has the range to measure γ dose from ten μSv to 3 μSv and x-ray dose form 1 μ Sv to 0.3 Sv due to the higher sensitivity of CaSO 4 : Dy to lower energy photons (20keV-50 keV) generated by diagnostic x-ray units. The x-ray radiation workers are at present nearly 35% of the total radiation workers monitored and this number is expected to grow as more and more number of x-ray workers are covered under this service. The upper limit of the x-ray dose range of the instrument is 0.3 Sv, whereas in the past one year it has been observed that at least 25% of the total overexposures reported in case of x-ray workers have recorded the dose more than 0.3 Sv. This paper presents the technique developed to extend the upper limit of the range from 0.3 Sv to 1 Sv for x-rays and 10 Sv for γ rays

  3. Thermoluminescence dosimeter reader

    International Nuclear Information System (INIS)

    Robertson, M.E.A.; Marshall, J.; Brabants, J.A.P.; Davies, M.E.

    1975-01-01

    An electric circuit arrangement is described including a photomultiplier tube and a high voltage source therefor also includes a feedback loop from the output of the tube to the high voltage source, and loop providing automatic gain stabilization for the tube. The arrangement is used in a dosimeter reader to provide sensitivity correction for the reader each time the reader is to be used

  4. Ionizing radiation source detection by personal TLD

    International Nuclear Information System (INIS)

    Marinkovic, O.; Mirkov, Z.

    2002-01-01

    The Laboratory for personal dosimetry has about 3000 workers under control. The most of them work in medicine. Some institutions, as big health centers, have different ionizing radiation sources. It is usefull to analyze what has been the source of irradiation, special when appears a dosimeter with high dose. Personal dosimetry equipment is Harshaw TLD Reader Model 6600 and dosimeters consist of two chips LiF TLD-100 assembled in bar-coded cards which are wearing in holders with one tissue-equivalent filter (to determine H(10)) and skin-equivalent the other (to determine H(0.07)). The calibration dosimeters have been irradiated in holders by different sources: x-ray (for 80keV and 100keV), 6 0C o, 9 0S r (for different distances from beta source) and foton beem (at radiotherapy accelerator by 6MeV, 10MeV and 18MeV). The dose ratio for two LiF cristals was calculated and represented with graphs. So, it is possible to calculate the ratio H(10)/H(0.07) for a personal TLD and analyze what has been the source of irradiation. Also, there is the calibration for determination the time of irradiation, according to glow curve deconvolution

  5. Thermoluminescent dosimeters (TLD) quality assurance network in the Czech Republic.

    Science.gov (United States)

    Kroutilķková, Daniela; Novotný, Josef; Judas, Libor

    2003-02-01

    The Czech thermoluminescent dosimeters (TLD) quality assurance network was established in 1997. Its aim is to pursue a regular independent quality audit in Czech radiotherapy centres and to support state supervision. The audit is realised via mailed TL dosimetry. The TLD system consists of encapsulated LiF:Mg,Ti powder (type MT-N) read with Harshaw manual reader model 4000. Basic mode of the TLD audit covers measurements under reference conditions, specifically beam calibration checks for all clinically used photon and electron beams. Advanced mode consists of measurements under both reference and non-reference conditions using a solid multipurpose phantom ('Leuven phantom') for photon beams. The radiotherapy centres are instructed to deliver to the TLD on central beam axis absorbed dose of 2 Gy calculated with their treatment planning system for a particular treatment set-up. The TLD measured doses are compared with the calculated ones. Deviations of +/-3% are considered acceptable for both basic and advanced mode of the audit. There are 34 radiotherapy centres in the Czech Republic. They undergo the basic mode of the TLD audit regularly every 2 years. If a centre shows a deviation outside the acceptance level, it is audited more often. Presently, most of the checked beams comply with the acceptance level. The advanced TLD audit has been implemented as a pilot study for the present. The results were mostly within the acceptance limit for the measurements on-axis, whereas for off-axis points they fell beyond the limit more frequently, especially for set-ups with inhomogeneities, oblique incidence and wedges. The results prove the importance of the national TLD quality assurance network. It has contributed to the improvement of clinical dosimetry in the Czech Republic. In addition, it helps the regulatory authority to monitor effectively and regularly radiotherapy centres.

  6. Thermoluminescent dosimeters (TLD) quality assurance network in the Czech Republic

    International Nuclear Information System (INIS)

    Kroutilikova, Daniela; Novotny, Josef; Judas, Libor

    2003-01-01

    Introduction: The Czech thermoluminescent dosimeters (TLD) quality assurance network was established in 1997. Its aim is to pursue a regular independent quality audit in Czech radiotherapy centres and to support state supervision. Materials and methods: The audit is realised via mailed TL dosimetry. The TLD system consists of encapsulated LiF:Mg,Ti powder (type MT-N) read with Harshaw manual reader model 4000. Basic mode of the TLD audit covers measurements under reference conditions, specifically beam calibration checks for all clinically used photon and electron beams. Advanced mode consists of measurements under both reference and non-reference conditions using a solid multipurpose phantom ('Leuven phantom') for photon beams. The radiotherapy centres are instructed to deliver to the TLD on central beam axis absorbed dose of 2 Gy calculated with their treatment planning system for a particular treatment set-up. The TLD measured doses are compared with the calculated ones. Deviations of ±3% are considered acceptable for both basic and advanced mode of the audit. Results: There are 34 radiotherapy centres in the Czech Republic. They undergo the basic mode of the TLD audit regularly every 2 years. If a centre shows a deviation outside the acceptance level, it is audited more often. Presently, most of the checked beams comply with the acceptance level. The advanced TLD audit has been implemented as a pilot study for the present. The results were mostly within the acceptance limit for the measurements on-axis, whereas for off-axis points they fell beyond the limit more frequently, especially for set-ups with inhomogeneities, oblique incidence and wedges. Conclusions: The results prove the importance of the national TLD quality assurance network. It has contributed to the improvement of clinical dosimetry in the Czech Republic. In addition, it helps the regulatory authority to monitor effectively and regularly radiotherapy centres

  7. Response of TLD-100"T"M microtubes to two RQR3 quality radiation beams

    International Nuclear Information System (INIS)

    Nunes, M.G.; Villani, D.; Almeida, S.B.; Vivolo, V.; Yoriyaz, H.; Louis, G.M.J.

    2016-01-01

    The present work compares the response of TLD-100"T"M microcubes to two RQR 3 diagnostic radiology reference quality radiation beams, defined by IEC-61267 norm, aiming to evaluate the detectability of TLD-100"T"M energy dependence reported in literature within the same reference quality radiation range. TLD-100"T"M microcubes reproducibility is assessed through the response of a second set of TLD-100"T"M microcubes, evaluated in a second thermoluminescence reader, to the RQR 3 diagnostic radiology reference quality radiation beam implemented at the Laboratorio de Calibracao de Instrumentos of IPEN, Sao Paulo, SP, Brazil. The dependence of TLD-100"T"M microcubes TL response was not detectable in these conditions and the reproducibility of the measurements is 90,2%. (author)

  8. Optimal selection of TLD chips

    International Nuclear Information System (INIS)

    Phung, P.; Nicoll, J.J.; Edmonds, P.; Paris, M.; Thompson, C.

    1996-01-01

    Large sets of TLD chips are often used to measure beam dose characteristics in radiotherapy. A sorting method is presented to allow optimal selection of chips from a chosen set. This method considers the variation

  9. Environmental monitoring with TLD in Costa Rica

    International Nuclear Information System (INIS)

    Mora, P.; Mora, E.

    2003-01-01

    Using thermoluminescent dosimeters (Harshaw TLD-200) the first set of costarican data on absorbed doses in air from natural radiation is obtained. During the period from September 1996 to october 2000 eight different sites throughout the country were chosen to instal the TLD stations. Each station had eight cards (five were changed every three months and three changed annually). The dosimeters were read in the Applied Nuclear Physics Laboratory using a 4000 Harshaw reader and with the help a mathematical algorithm and the equipment calibration factors the dose rate in air (nGy h -1 ) was calculated. The national average is 108.9 ± 32.4 nGy h -1 , the lowest values (in nGy h -1 ) were obtain at sea level at Quebrada Honda with 53 ± 11 and the highest values (in nGy h -1 ) at Cartago with 160 ± 19. A slight increase with altitude is observed even though the Cartago station was always the highest. The values found agree with reported worldwide values for environmental doses in air. (Author) [es

  10. Study of physical factors affecting the TLD readout

    International Nuclear Information System (INIS)

    Ahmed, Amira Abd Elrhman Ebrahim

    2015-10-01

    The aim of the study was to study the effects of physical factors in TLD reading. The dosimeters have been irradiated with x rays of (0.5 mGy to 5 mGy) using plastic holder with Aluminum filters with dimensions 1.5 x 0.8 mm and 0.5 mm in thickness to obtain the equivalent dose Hp (10) flux of nitrogen gas and annealing after data collection by TLD Reader Analyzer 04 (Version 0.9.400 micro lab (krakow 2012). The count and dose analysis shows that; The count/s given by TLD appears to be higher in case of using filtration which was 7189.9 eps in contrast with reading without filter which was 4055.8 eps. There was proportional linear relationship between the applied dose and the TLD count for both cases with and without filter. And the correlation could be fitted in the form of equations: y=423.9 x + 1023 and y = 432.5 x + 405.3 for filtered and y refers to count/s. Such increment in count is ascribed to increasing applied radiation dose as well it indicates and confirms the linearity of TLD in measuring the radiation dose since R 2 = 0.9. However the count with filter for the applied radiation dose in mGy was greater than that without filter. The that measured with pellets annealing (reading of zero doses). TLD pellets reading without zero dose measurement usually gives greater dose ( 441.8 and 563.6 μGy) relative to the case where the zero doses have been measured which were 289.6 and 429.2 μGy, respectively. While the effect of using filtration is so obvious and leads to increase of zero dose, respectively relative to dose s of un reading of zero dose, and reading of zero dose, but without filter.(Author)

  11. Towards an automated TLD system that meets international requirements

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.; Vanamo, V.

    1988-01-01

    The new recently introduced fully automated TLD system developed by Alnor OY on the basis of the Riso prototype, is intended to meet draft IEC/ISO proposals and ANSI requirements. Part of the system is a personal dosemeter badge and an environmental dosemeter package following ICRU recommendations. The overall system consists of a software-controlled automated reader, a programable irradiator/calibrator, a computer, and dosemeters for environmental, whole body, extremity and clinical applications. The personal TLD badge that contains four TLD pellets is designed to agree with ICRU H p (10) and H s (0.07) quantities for determining dose equivalent. The badge can accommodate a large variety of the most commonly used solid TL dosemeter products. A special effort was put into the evaluation of skin dose by considering the use of graphite-mixed hot-sintered LiF pellets. The TLD system is described and results from a performance test that comprised measurements of photon energy response, angular dependence, and reproducibility are presented

  12. Personal exposure control using TLD

    International Nuclear Information System (INIS)

    Ishiguro, Hideharu; Takeda, Shinso

    1979-01-01

    In the Tokai Works of the Power Reactor and Nuclear Fuel Development Corporation (PNC), for personal exposure control, the switching from film badges to TLD badges (and also finger-ring type local dosimeters) was made in fiscal 1974. The facilities involved are a fuel reprocessing plant, a PuO 2 -UO 2 mixed fuel production facility, and a centrifugal uranium enrichment development facility. The types of radiation concerned are various, such as γ(x), β and n. The situation of personal exposure control with TLD and the dose evaluation methods for respective radiations are explained. The number of personnel subject to exposure control, including transient people, is about 2500 - 3000 per three months. The TLD badges used are a special PNC type with TLDs to measure separately γ(x), β and n. With casings made of ABS resin, the external dimensions are 76 mm x 46 mm. (J.P.N.)

  13. Environmental effects on TLD 100

    International Nuclear Information System (INIS)

    Lilley, E.; Howard, R.

    1976-01-01

    Reference is made to a recent paper by Dhar et al (Health Phys.; 25:427 (1973)) in which significant differences in the sensitivity of TLD 100 crystals following the same heat treatments in different environments, were reported. Similar work is here reported on TLD 100 at 400 0 C with half the crystals being heat treated in vacuum, irradiated and readout an then annealed in air, irradiated and readout while the other half of the crystals were air annealed and readout before vacuum annealing and readout. In both cases no significant change was detected in contrast to the results of Dhar et al. (U.K.)

  14. Minimizing TLD-DRD differences

    International Nuclear Information System (INIS)

    Riley, D.L.; McCoy, R.A.; Connell, W.D.

    1987-01-01

    When substantial differences exist in exposures recorded by TLD's and DRD's, it is often necessary to perform an exposure investigation to reconcile the difference. In working with several operating plants, the authors have observed a number of causes for these differences. This paper outlines these observations and discusses procedures that can be used to minimize them

  15. Comparison of LiF (TLD-100 and TLD-100H) detectors for extremity monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Freire, L. [Departamento de Proteccao Radiologica e Seguranca Nuclear, Instituto Tecnologico e Nuclear, E.N. 10, 2683-953 Sacavem (Portugal); Laboratorio de Medicina Nuclear, Lda, Atomedical, Rua Helena Felix, 11D, 1600-121 Lisboa (Portugal); Calado, A.; Cardoso, J.V.; Santos, L.M. [Departamento de Proteccao Radiologica e Seguranca Nuclear, Instituto Tecnologico e Nuclear, E.N. 10, 2683-953 Sacavem (Portugal); Alves, J.G. [Departamento de Proteccao Radiologica e Seguranca Nuclear, Instituto Tecnologico e Nuclear, E.N. 10, 2683-953 Sacavem (Portugal)], E-mail: jgalves@itn.pt

    2008-02-15

    In this work the results aimed at assessing the performance of two types of LiF detectors, TLD-100 and TLD-100H, used in the context of extremity dosimetry are presented. Each detector variety was studied for reproducibility, batch homogeneity, residual dose, linearity and energy dependence using, when appropriate, the {sup 90}Sr/{sup 90}Y radiation source built-in one of the Harshaw 6600 readers, the ISO narrow X-ray beams of N30, N40, N60, N80, N100 and N120 or the gamma radiations of {sup 137}Cs and {sup 60}Co. Two calibration energies (N120 and {sup 137}Cs) were also used. The reproducibility and linearity results indicate that both LiF:Mg,Ti and LiF:Mg,Cu,P performed equally well. However, LiF:Mg,Cu,P presents a higher residual signal. In terms of energy dependence, LiF:Mg,Cu,P shows less variation than LiF:Mg,Ti particularly when N120 is used as calibration radiation. This seems to be a more realistic setup since the energy of the most frequently used radioisotopes in Nuclear Medicine departments with single photon emission computed tomography (SPECT) use gamma radiation energies closer to N120 than to {sup 137}Cs.

  16. Environmental radiation monitoring of nuclear sites by thermoluminescent dosimeters (TLD)

    International Nuclear Information System (INIS)

    Duftschmid, K.E.; Strachotinsky, Ch.

    1978-04-01

    The measurement of environmental radiation doses around nuclear facilities requires the detection of few mrem/year. The properties of the automatic TLD-system Harshaw Mod. 2271 for such measurements have been evaluated under practical conditions and optimized techniques derived. The automatic TLD-system is based on LiF dosimeter cards with two crystals providing gamma and beta dose values. Limit of detection defined as three standard deviations of residuel dose is 1,2 mR. Automatic readout combined with electronic data evaluation are especially useful for large monitoring networks. Practical intercomparisons of this dosimeter with bulb-type CaF 2 detectors have been performed showing good agreement of both detector. Although bulb-dosimeters proved to be extremely sensitive with a limit of detection at 0,012 mR which makes them very suitable for very short exposure times, the automatic LiF system is superior in regards of man power requirement if monthly monitoring periods are sufficient. The system has been tested in practice during two international intercomparisons performed by the US Department of Energy - Health and Safety Laboratory New York and the Physikalisch Technische Bundesanstalt Braunschweig, Germany, showing excellent agreement. Furthermore a routine monitoring network consisting of 12 measurement positions around the Research Center Seibersdorf has been operated with this technique since more than two years. (author)

  17. Electronic stability and reproducible accuracy of HARSHAW 2000(A,B) TLD-analyzer

    International Nuclear Information System (INIS)

    Yossef, S.K.; Henaish, B.A.

    1985-01-01

    Nowadays, the thermoluminescence techniques utilizing natural materials and assorted chemical compound of various geometrical configurations are widely and popularly used on the international scale as a dose evaluation system. The main problems which are usually encounting the accuracy of the evaluated dose by means of such various dosimeter forms are the long and short term stability of the measuring system. Also this manuscript is a very essential details stated out the principle mechanisms which cause that produced TL-readers instability. As it is stated out through the different sections of this issue, it is mainly due to the interior mechanisms of the TLD measuring systems. Further more, the various detailed discussions availed through the different sections of such issue are mainly accompanied by long term experiences gained by the authors. A novel heating cycle mechanism applied to HARSHOW 2000(A and b) TLD analyzer is tested experimentally. Also long and short term stability beside the reproducibility of the TLD reader system were experimentally tested under various seasonable environmental thermal conditions. The results of experimental measurements were noted for a total duration of six months during continuous operation of the TLD reader for one year. 1 fig., 3 tab

  18. A microcontroller based readout unit for a smart personnel monitoring TLD badge

    International Nuclear Information System (INIS)

    Gaonkar, U.P.; Kulkarni, M.S.; Kannan, S.

    1997-01-01

    An automated TLD personnel monitoring system is under development to cope up with the requirements of personnel monitoring of rapidly growing number of radiation workers. The core of the system is a smart TLD badge incorporating a memory device and a microcontroller based readout unit for reading the memory contents of the badge. The memory is used to store personnel data including the accumulated dose data. The reader unit has a serial RS 232C interface for connection to a PC for entering/modifying data in the memory. A password protected software has also been developed in C for entering/modifying the data in the single memory. 3 figs

  19. Performance analysis of the TNO TLD individual monitoring service

    International Nuclear Information System (INIS)

    Dijk, J.W.E. van; Julius, H.W.

    1990-01-01

    The purpose of this study was to analyse the performance and to establish the lowest detectable occupational dose (LDOD) of the TNO TL dosemeter, in use for large scale routine individual monitoring since 1983. The TNO individual monitoring service uses three TLD reader systems and over 45000 TL dosemeters, designed to measure H s (0.07) and H p (10). Each reader system is normalised daily and each individual dosemeter is calibrated every ten readout cycles. The performance of the service is monitored by a double blind experimental set-up. A series of 10 routine dosemeters is issued every fortnight, mailed, exposed by staff not involved in the monitoring service, sent back and evaluated. The conclusion of this study is that the lowest detectable occupational dose is less than 0.04 mSv and that the integrated dose at the level of the annual dose limit is measured within 2%. (author)

  20. An automated thermoluminescence dosimetry (TLD) system

    International Nuclear Information System (INIS)

    Kicken, P.J.H.; Huyskens, C.J.

    1979-01-01

    In the Health Physics Division of the Eindhoven University of Technology work is going on in developing an automated TLD-system. Process automization, statistical computation, dose calculation as well as dose recording are carried out, using a microcomputer and floppy disk unit. The main features of this TLD-system are its low costs, flexibility, easy to operate, and the feasibility for use in routine dosimetry as well as in complex TLD research. Because of its modular set-up several components of the system are multifunctional in other operations. The system seems suited for medium sized Health Physics groups. (Auth.)

  1. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-12-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the third quarter of 1991

  2. CUZCO READER.

    Science.gov (United States)

    SOLA, DONALD F.

    WRITTEN TO ACCOMPANY THE SPOKEN CUZCO QUECHUA MATERIALS, THIS READER CONSISTS OF SHORT SELECTIONS ACTUALLY RECORDED IN THE FIELD AND REPRESENTING SEVERAL SUBDIALECTS SPOKEN IN RURAL SECTIONS OF THE DEPARTMENT OF CUZCO, PERU. INCLUDED ARE DIALOGS, STORIES, SONGS, CULTURAL SELECTIONS, AND INTERVIEWS. THE FORMAT GIVES THE CUZCO QUECHUA DIALECT AND…

  3. Environmental monitoring system with TLD

    International Nuclear Information System (INIS)

    Aguerre, L.; Carelli, J.; Gregori, B.

    2006-01-01

    Presently work the methodology used by the Laboratory of Thermoluminescent Dosimetry (TLD) of the Nuclear Regulatory Authority (RNA) to gauge it system of environmental monitoring in function of the media absorbed dose rate in free air and the environmental dose equivalent, H * (10), according to the recommendation ICRU Report 47 is described. It was studied the response of the environmental dosemeter (DA) in fields of photonic radiation of energies W60, Wl 10, W200 and 137 Cs. The irradiations were carried out following the recommendations of the standard ISO:4037. It was analyzed the response in the DA of the detectors LiF: Mg, Ti and CaF 2 : Dy for the different radiation qualities and the relative response at 137 Cs of both. The methodology used in the evaluation of the dose includes: the correction of the readings of both detectors by fading, gotten experimentally, the witness of transfers, the energy answer and the value of the zero. The dose is calculated applying the average pondered in uncertainty of the dose obtained for each type of detector. Its were analyzed and calculated the uncertainties that affect to the measurement following the recommendation of the Argentine standard IRAM 35050. The detection limit of the absorbed dose rate in free air of this system it is 3.5 n Gy/h for a period of sampling of 3 months. With this detection limit environmental dose equivalent rates of the order of 70 n Sv/h are measured with an expanded uncertainty of the order of 10% with a cover factor k = 2. (Author)

  4. Application of Glow Curve Deconvolution Method to Evaluate Low Dose TLD LiF

    International Nuclear Information System (INIS)

    Kurnia, E; Oetami, H R; Mutiah

    1996-01-01

    Thermoluminescence Dosimeter (TLD), especially LiF:Mg, Ti material, is one of the most practical personal dosimeter in known to date. Dose measurement under 100 uGy using TLD reader is very difficult in high precision level. The software application is used to improve the precision of the TLD reader. The objectives of the research is to compare three Tl-glow curve analysis method irradiated in the range between 5 up to 250 uGy. The first method is manual analysis, dose information is obtained from the area under the glow curve between pre selected temperature limits, and background signal is estimated by a second readout following the first readout. The second method is deconvolution method, separating glow curve into four peaks mathematically and dose information is obtained from area of peak 5, and background signal is eliminated computationally. The third method is deconvolution method but the dose is represented by the sum of area of peak 3,4 and 5. The result shown that the sum of peak 3,4 and 5 method can improve reproducibility six times better than manual analysis for dose 20 uGy, the ability to reduce MMD until 10 uGy rather than 60 uGy with manual analysis or 20 uGy with peak 5 area method. In linearity, the sum of peak 3,4 and 5 method yields exactly linear dose response curve over the entire dose range

  5. Analysis of read-out heating rate effects on the glow peaks of TLD-100 using WinGCF software

    Energy Technology Data Exchange (ETDEWEB)

    Bauk, Sabar, E-mail: sabar@usm.my [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Hussin, Siti Fatimah [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Alam, Md. Shah [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Physics Department, Shahjalal University of Science and Technology, Sylhet (Bangladesh)

    2016-01-22

    This study was done to analyze the effects of the read-out heating rate on the LiF:Mg,Ti (TLD-100) thermoluminescent dosimeters (TLD) glow peaks using WinGCF computer software. The TLDs were exposed to X-ray photons with a potential difference of 72 kVp and 200 mAs in air and were read-out using a Harshaw 3500 TLD reader. The TLDs were read-out using four read-out heating rates at 10, 7, 4 and 1 °C s{sup −1}. It was observed that lowering the heating rate could separate more glow peaks. The activation energy for peak 5 was found to be lower than that for peak 4. The peak maximum temperature and the integral value of the main peak decreased as the heating rate decreases.

  6. Policy Reader

    International Nuclear Information System (INIS)

    1985-09-01

    This policy reader comprises: Correspondence; Memorandum of Understanding between the US Department of Transportation and the US Department of Energy for the Transportation of Radioactive Materials under the Nuclear Waste Policy Act; Internal Guidelines for Interactions with Communities and Local Governments; Statement by Ben C. Rusche before the Committee on Interior and Insular Affairs, Subcommittee on Energy and the Environment, US House of Representatives, September 13, 1985; Speech presented by Ben C. Rusche before the ANS/CNS/AESJ/ENS Topical Meeting, Pasco, Washington, September 24, 1985 - ''Status of the United States' High-Level Nuclear Waste Disposal Program''; and ''DOE Seeks Comments on Nuclear Transportation Planning,'' DOE News, September 30, 1985

  7. TLD system for the monitoring of the environmental radioactivity

    International Nuclear Information System (INIS)

    Stochioiu, Ana; Sahagia, Maria; Tudor, Ion

    2008-01-01

    The paper presents a high sensitivity TLD system, designed for the survey of the environmental radioactivity. It is based on the use of TL detectors type LiF:Mg, Cu, P, commercially known as GR-200A. The dosimeter designed in our Institute, contains 3 detectors, and the measurement value is calculated as the arithmetic mean. A very sensitive, TL Reader, READER ANALYSER RA'94 was chosen and an optimal thermal cycle was designed, such as to enhance the measurement performances. For each placement, a set of 3 dosemeters is used, and survey intervals from 1 to 100 days, depending on the radioactivity level and reporting requirements, are selected. The technical characteristics of the system were determined by exposing the dosimeters in reference X and gamma radiation fields, such as required by the IEC standard 61066:iun.2006 'Thermoluminescence dosimetry systems for personal and environmental monitoring'. The main technical parameters are of highest quality and recommend it for use in the survey of the environmental radioactivity, at the level of ambient dose equivalent rate, due to normal natural radioactivity, in open areas. The paper describes the method of characterisation and measurement results, as well as their relevance. (author)

  8. Reader survey

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-10-15

    Many, thanks to the hundreds of people who took the time to reply to the CERN Courier readership survey questionnaire published in our May issue. Bringing out a monthly journal is a lonely business. Issue after issue goes out, and the only response is when there's an occasional factual error. Send out a readership survey and a faint echo comes back. Most striking was the sheer enthusiasm of the replies. Despite the current erosion of support in the US (see page 2), subatomic physics has significant world-wide box-office appeal. Most important was to find out who our readers are. 61% of the replies came from Europe, 21% from the USA, 14% from elsewhere, (including the former Soviet Union), and 4% from inside CERN. Not surprisingly, the main audience (37%) is in the high energy physics sector. Then comes teaching (31%), followed closely by accelerators operations and design (12%) and industry (11%). Apart from detailed breakdowns of readership and feedback on the journal's content and style, the replies revealed several major features. Firstly, the CERN Courier is widely read and appreciated. There are a lot of people outside the immediate research field who want to keep broadly up to date with the latest developments in high energy physics and related fields, without getting too involved in details. It was gratifying to receive replies from far-flung places (Nepal, Indonesia,....), and learn how much distant readers appreciate getting such regular information. 'It helps us feel part of the world scene,' was a typical such reply, from Australia. Despite jet airplanes, fax and electronic mail, our planet is still big.

  9. Reader survey

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Many, thanks to the hundreds of people who took the time to reply to the CERN Courier readership survey questionnaire published in our May issue. Bringing out a monthly journal is a lonely business. Issue after issue goes out, and the only response is when there's an occasional factual error. Send out a readership survey and a faint echo comes back. Most striking was the sheer enthusiasm of the replies. Despite the current erosion of support in the US (see page 2), subatomic physics has significant world-wide box-office appeal. Most important was to find out who our readers are. 61% of the replies came from Europe, 21% from the USA, 14% from elsewhere, (including the former Soviet Union), and 4% from inside CERN. Not surprisingly, the main audience (37%) is in the high energy physics sector. Then comes teaching (31%), followed closely by accelerators operations and design (12%) and industry (11%). Apart from detailed breakdowns of readership and feedback on the journal's content and style, the replies revealed several major features. Firstly, the CERN Courier is widely read and appreciated. There are a lot of people outside the immediate research field who want to keep broadly up to date with the latest developments in high energy physics and related fields, without getting too involved in details. It was gratifying to receive replies from far-flung places (Nepal, Indonesia,....), and learn how much distant readers appreciate getting such regular information. 'It helps us feel part of the world scene,' was a typical such reply, from Australia. Despite jet airplanes, fax and electronic mail, our planet is still big

  10. Neutron area monitor with TLD pairs

    International Nuclear Information System (INIS)

    Guzman G, K. A.; Borja H, C. G.; Valero L, C.; Hernandez D, V. M.; Vega C, H. R.

    2011-11-01

    The response of a passive neutron area monitor with pairs of thermoluminescent dosimeters has been calculated using the Monte Carlo code MCNP5. The response was calculated for one TLD 600 located at the center of a polyethylene cylinder, as moderator. When neutrons collide with the moderator lose their energy reaching the TLD with thermal energies where the ambient dose equivalent is calculated. The response was calculated for 47 monoenergetic neutron sources ranging from 1E(-9) to 20 MeV. Response was calculated using two irradiation geometries, one with an upper source and another with a lateral source. For both irradiation schemes the response was calculated with the TLDs in two positions, one parallel to the source and another perpendicular to the source. The advantage of this passive neutron monitor area is that can be used in locations with intense, pulsed and mixed radiation fields. (Author)

  11. Determination of the TLD-100 physical parameters

    International Nuclear Information System (INIS)

    Paucar J, J.; Picon C, C.

    1998-01-01

    This study was realized in the Physics service at the Radiotherapy Department of the National Institute of Neoplasic Diseases in Lima, Peru, it was determined the activation energy, the kinetic order and the frequency factor of the fifth peak of the TLD-100 thermoluminescent spectra using different algorithms. This was carried out in parallel with the implementation and design of a software and an interface associated with the Tl lecturer which allows a semiautomatic control for a thermoluminescent lecturer process. (Author)

  12. TLD territorial network in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Kroutilikova, D. [National Radiation Protection Institute, Prague (Czech Republic)

    1996-12-31

    At present, there are 236 measuring points practically homogeneously distributed on the territory of the Czech Republic. 98 measuring points are distributed as local TLD-networks in the surroundings of Czech two nuclear power plants. Both of the TLD-networks are operated by the National Radiation Protection Institute in Prague. The dosimeters hitherto used are the CaSO{sub 4}:Dy-teflon detectors placed in TL-badges and shielded on both sides by energy compensation filters composed of lead and tin. Recently, a new modernization of the measuring system, type of dosimeter and methods of evaluation is under way. From 1996 the Czech Radiation Monitoring Network will be used the TLD system HARSHAW 4000, along with the type 8807 ENVIRONMENTAL DOSIMETER. The dosimeter is composed of four TL-elements - two LiF and two CaF{sub 2}, placed in a plastic badge. In addition, the CaF{sub 2} elements are shielded on both sides by energy compensation filters composed of tantalum and lead. Before the routine use of the new system a testing of the dosimeters was made. The following text summarizes the obtained results (J.K.). 4 tabs.

  13. RFID based TLD monitoring system - a prospective development

    International Nuclear Information System (INIS)

    Jeevanram, S.S.; Pawar, S.T.; Mahule, K.N.; Rath, D.P.

    2008-01-01

    Thermo Luminescence Dosimetry (TLD) is an established method of monitoring the radiation dose received by workers in radiation environments. In Radiometallurgy Laboratory, BARC, the TLD movement inside a nuclear facility is completely carried out by a radiation worker. However, there is a chance that the TLDs may get lost in laboratories or some places without the knowledge of the concerned TLD user or health physicist. It may later lead to a false effective dose. Effort is being done to initiate a RFID based TLD monitoring system so that the use of TLD can be acknowledged through a self operating software which can prevent misuse of the detector. A novel method of improving the administrative control through Radio Frequency Identification (RFID) based monitoring to avoid such inadvertent misplacement of TLD, is in progress. This paper discusses the method and techniques through which administrative control can be exercised to reduce the number of such in explainable exposures. (author)

  14. Dose measurements in space by the Hungarian Pille TLD system

    International Nuclear Information System (INIS)

    Apathy, I.; Deme, S.; Feher, I.; Akatov, Y.A.; Reitz, G.; Arkhanguelski, V.V.

    2002-01-01

    Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensions, high sensitivity, good stability, wide measuring range, resistance to environmental effects, and relatively low cost. Nevertheless, they have the general disadvantage that for evaluation purposes they need a laboratory or large--in mass and power consumption--terrestrial equipment, and consequently they cannot provide time-resolved dose data during long-term space flights. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosemeter systems for measuring cosmic radiation doses in the 10 μGy to 10 Gy range, consisting of a set of bulb dosemeters and a compact, self-contained, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A detailed description of the system is given and the comprehensive results of these measurements are summarised

  15. Postal TLD audit in radiotherapy in the Czech Republic

    International Nuclear Information System (INIS)

    Kapucianova, M.; Ekendah, D. l.; Bulanek, B.

    2014-01-01

    The postal TLD audit in radiotherapy is an independent check of dose applied by radiotherapy centers. Our poster provides basic information on the methodology of dose determination within the TLD audit. An overview of different versions of the TLD audit that are focused on specific techniques in radiotherapy is given. We also present results of so called basic version of the TLD audit that is performed regularly for purposes of the State Office for Nuclear Safety. Moreover, results of intercomparison measurements organized by the IAEA (International Atomic Energy Agency), in which our laboratory takes part every year, are shown.The methodology of dose determination is based on TL measurement of LiF:Mg,Ti powder. The TL dosemeter (TLD) has form of a plastic capsule containing approximately 160 mg of this material. Before the TL reading, the powder of each particular irradiated dosemeter is divided into 9 identical samples by means of an accurate dispenser. The dosemeter response is given as average of TL responses of the 9 samples. The dose absorbed in water is computed from the TLD response by application of calibration factor and correction coefficients for elimination of energy dependence, supra-linearity and fading of the TL material. The evaluation of the TLD audit is based on comparison of the dose measured by the TLD and the dose stated by a radiotherapy center. Relative deviation between these doses is calculated. Several versions of the TLD audit are available. (authors)

  16. Thermoluminescent accident dose reader with photodiode; Termoluminiscencni litalnik akcidentnih doz s fotodiodo

    Energy Technology Data Exchange (ETDEWEB)

    Miklavzic, U; Mihelic, M [Institut Jozef Stefan, Ljubljana (Yugoslavia)

    1982-07-01

    The field version of TL reader for accident dose region 0.01-20 Gy is described. For light detection, the thermostated photodiode was used permitting measurements at the ambient temperatures from -20 C degrees to 50 C degrees, and a new mode of the glow curve integration. Results can be presented as integral or peak values of the glow curve. The reader was adapted for dosemeters IJS-TLD08 from sintered CaF2:Mn pellets. (author)

  17. Reproducibility study of TLD-100 micro-cubes at radiotherapy dose level

    International Nuclear Information System (INIS)

    Rosa, Luiz Antonio R. da; Regulla, Dieter F.; Fill, Ute A.

    1999-01-01

    The precision of the thermoluminescent response of Harshaw micro-cube dosimeters (TLD-100), evaluated in both Harshaw thermoluminescent readers 5500 and 3500, for 1 Gy dose value, was investigated. The mean reproducibility for micro-cubes, pre-readout annealed at 100 deg. C for 15 min, evaluated with the manual planchet reader 3500, is 0.61% (1 standard deviation). When micro-cubes are evaluated with the automated hot-gas reader 5500, reproducibility values are undoubtedly worse, mean reproducibility for numerically stabilised dosimeters being equal to 3.27% (1 standard deviation). These results indicate that the reader model 5500, or, at least, the instrument used for the present measurements, is not adequate for micro-cube evaluation, if precise and accurate dosimetry is required. The difference in precision is apparently due to geometry inconsistencies in the orientation of the imperfect micro-cube faces during readout, requiring careful and manual reproducible arrangement of the selected micro-cube faces in contact with the manual reader planchet

  18. A Computerized QC Analysis of TLD Glow Curves for Personal Dosimetry Measurements Using TagQC Program

    International Nuclear Information System (INIS)

    Primo, S.; Datz, H.; Dar, A.

    2014-01-01

    The External Dosimetry Lab (EDL) at the Radiation Safety Division at Soreq Nuclear Research Center (SNRC) is ISO 17025 certified and provides its services to approximately 13,000 users throughout the country from various sectors such as medical, industrial and academic. About 95% of the users are monitored monthly for X-rays, and radiation using Thermoluminescence Dosimeter (TLD) cards that contain three LiF:Mg,Ti elements and the other users, who work also with thermal neutrons, use TLD cards that contain four LiF:Mg,Ti elements. All TLD cards are measured with the Thermo 8800pc reader.Suspicious TLD glow curve (GC) can cause wrong dose estimation so the EDL makes great efforts to ensure that each GC undergoes a careful QC procedure. The current QC procedure is performed manually and through a few steps using different softwares and databases in a long and complicated procedure: EDL staff needs to export all the results/GCs to be checked to an Excel file, followed by finding the suspicious GCs, which is done in a different program (WinREMS), According to the GC shapes (Figure 1 illustrates suitable and suspicious GC shapes) and the ratio between the elements result values, the inspecting technician corrects the data

  19. A personnel TLD system with person identification

    International Nuclear Information System (INIS)

    Widell, C.O.

    1974-01-01

    The TLD system uses Li 2 B 4 O 7 :Mn, Si sintered tablets which are heated by hot nitrogen. The slide which holds the tablets is coded by a self adhesive polyester-aluminium tape. This tape is BCD coded in an ordinary tape punch. The information on the punched tape includes a ten digit social-security number and a two digit information on location and type of dosimetry. By this system dosimetric data is directly transfered into a central dose register for Sweden. All personnel doses are there stored on social-security numbers. (author)

  20. Experience of TLD personnel monitoring laboratory

    International Nuclear Information System (INIS)

    Jakhete, Prashant

    2002-01-01

    Full text: Renentech Laboratories is the first Private Enterprise in India to have been chosen to provide Personnel radiation monitoring services to radiation workers at different parts of the country. Since 1992 the Company has been manufacturing TLD phosphor powder of requisite quality and from 1995 commenced the production of TLD cards for radiation monitoring. After getting the necessary approval from the competent authorities in the country, the company undertook a rigorous quality assurance programme and received the accreditation in 1999 to carry out the personnel monitoring of radiation. Since then the trained staff of the Company is covering 1200 institutions in 16 states where radiation is being used. This translates to processing of 60,000 Till cards annually, the maximum limit permitted by BARC. Processing of exposure data is done strictly according well-laid guidelines. Any cases of overexposure are immediately referred to Calibration and Dose Record Section of BARC to meet the regulatory requirements. Necessary procedural guidelines are followed to handle such cases. In this lecture, learning, operation and implementation experience of a typical Private Company in a task, which, hitherto had been regarded as exclusive responsibility of state owned institution, is enumerated

  1. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1992-06-01

    The US Nuclear Regulatory Commission (NRC) Direct Radiation Monitoring Network is operated by the NRC in cooperation with participating states to provide continuous measurement of the ambient radiation levels around licensed NRC facilities, primarily power reactors. Ambient radiation levels result from naturally occurring radionuclides present in the soil, cosmic radiation constantly bombarding the earth from outer space, and the contribution, if any, from the monitored facilities and other man-made sources. The Network is intended to measure radiation levels during routine facility operations and to establish background radiation levels used to assess the radiological impact of an unusual condition, such as an accident. This report presents the radiation levels measured around all facilities in the Network for the first quarter of 1992. All radiation measurements are made using small, passive detectors called thermoluminescent dosimeters (TLDs), which provide a quantitative measurement of the radiation levels in the area in which they are placed. Each site is monitored by arranging approximately 40 to 50 TLD stations in two concentric rings extending to about five miles from the facility. All TLD stations are outside the site boundary of the facility

  2. What Can Readers Read after Graded Readers?

    Science.gov (United States)

    McQuillan, Jeff

    2016-01-01

    Nation (2014) concluded that most of the vocabulary one needs to read challenging texts in English can be acquired incidentally through voluminous reading. This study examines possible texts that second language (L2) readers can use to move from controlled-vocabulary materials such as graded readers, which go up through approximately the…

  3. Robust determination of effective atomic numbers for electron interactions with TLD-100 and TLD-100H thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Taylor, M.L.

    2011-01-01

    Lithium fluoride thermoluminescent dosimeters (TLD) are the most commonly implemented for clinical dosimetry. The small physical magnitude of TLDs makes them attractive for applications such as small field measurement, in vivo dosimetry and measurement of out-of-field doses to critical structures. The most broadly used TLD is TLD-100 (LiF:Mg,Ti) and, for applications requiring higher sensitivity to low-doses, TLD-100H (LiF:Mg,Cu,P) is frequently employed. The radiological properties of these TLDs are therefore of significant interest. For the first time, in this study effective atomic numbers for radiative, collisional and total electron interaction processes are calculated for TLD-100 and TLD-100H dosimeters over the energy range 1 keV-100 MeV. This is undertaken using a robust, energy-dependent method of calculation rather than typical power-law approximations. The influence of dopant concentrations and unwanted impurities is also investigated. The two TLDs exhibit similar effective atomic numbers, ranging from approximately 5.77-6.51. Differences arising from the different dopants are most pronounced in low-energy radiative effects. The TLDs have atomic numbers approximately 1.48-2.06 times that of water. The effective atomic number of TLD-100H is consistently higher than that of TLD-100 over a broad energy range, due to the greater influence of the higher-Z dopants on the electron interaction cross sections. Typical variation in dopant concentration does not significantly influence the effective atomic number. The influence on TLD-100H is comparatively more pronounced than that on TLD-100. Contrariwise, unwanted hydroxide impurities influence TLD-100 more than TLD-100H. The effective atomic number is a key parameter that influences the radiological properties and energy response of TLDs. Although many properties of these TLDs have been studied rigorously, as yet there has been no investigation of their effective atomic numbers for electron interactions. The

  4. Determination of the TLD-100 physical parameters; Determinacion de parametros fisicos del TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Paucar J, J.; Picon C, C. [Instituto Nacional de Enfermedades Neoplasicas. INEN. Av. Angamos Este 2520, Lima 34 (Peru)

    1998-12-31

    This study was realized in the Physics service at the Radiotherapy Department of the National Institute of Neoplasic Diseases in Lima, Peru, it was determined the activation energy, the kinetic order and the frequency factor of the fifth peak of the TLD-100 thermoluminescent spectra using different algorithms. This was carried out in parallel with the implementation and design of a software and an interface associated with the Tl lecturer which allows a semiautomatic control for a thermoluminescent lecturer process. (Author)

  5. Application of combined TLD and CR-39 PNTD method for measurement of total dose and dose equivalent on ISS

    International Nuclear Information System (INIS)

    Benton, E.R.; Deme, S.; Apathy, I.

    2006-01-01

    To date, no single passive detector has been found that measures dose equivalent from ionizing radiation exposure in low-Earth orbit. We have developed the I.S.S. Passive Dosimetry System (P.D.S.), utilizing a combination of TLD in the form of the self-contained Pille TLD system and stacks of CR-39 plastic nuclear track detector (P.N.T.D.) oriented in three mutually orthogonal directions, to measure total dose and dose equivalent aboard the International Space Station (I.S.S.). The Pille TLD system, consisting on an on board reader and a large number of Ca 2 SO 4 :Dy TLD cells, is used to measure absorbed dose. The Pille TLD cells are read out and annealed by the I.S.S. crew on orbit, such that dose information for any time period or condition, e.g. for E.V.A. or following a solar particle event, is immediately available. Near-tissue equivalent CR-39 P.N.T.D. provides Let spectrum, dose, and dose equivalent from charged particles of LET ∞ H 2 O ≥ 10 keV/μm, including the secondaries produced in interactions with high-energy neutrons. Dose information from CR-39 P.N.T.D. is used to correct the absorbed dose component ≥ 10 keV/μm measured in TLD to obtain total dose. Dose equivalent from CR-39 P.N.T.D. is combined with the dose component <10 keV/μm measured in TLD to obtain total dose equivalent. Dose rates ranging from 165 to 250 μGy/day and dose equivalent rates ranging from 340 to 450 μSv/day were measured aboard I.S.S. during the Expedition 2 mission in 2001. Results from the P.D.S. are consistent with those from other passive detectors tested as part of the ground-based I.C.C.H.I.B.A.N. intercomparison of space radiation dosimeters. (authors)

  6. The IAEA/WHO TLD postal programme for radiotherapy hospitals

    International Nuclear Information System (INIS)

    Izewska, J.; Andreo, P.

    2000-01-01

    Since 1969 the International Atomic Energy Agency (IAEA), together with the World Health Organization (WHO), has performed postal TLD audits to verify the calibration of radiotherapy beams in developing countries. A number of changes have recently been implemented to improve the efficiency of the IAEA/WHO TLD programme. The IAEA has increased the number of participants and reduced significantly the total turn-around time to provide results to the hospitals within the shortest possible time following the TLD irradiations. The IAEA has established a regular follow-up programme for hospitals with results outside acceptance limits of ±5%. The IAEA has, over 30 years, verified the calibration of more than 3300 clinical photon beams at approximately 1000 radiotherapy hospitals. Only 65% of those hospitals who receive TLDs for the first time have results within the acceptance limits, while more than 80% of the users that have benefited from a previous TLD audit are successful. The experience of the IAEA in TLD audits has been transferred to the national level. The IAEA offers a standardized TLD methodology, provides Guidelines and gives technical back-up to the national TLD networks. The unsatisfactory status of the dosimetry for radiotherapy, as noted in the past, is gradually improving however, the dosimetry practices in many hospitals in developing countries need to be revised in order to reach adequate conformity to hospitals that perform modern radiotherapy in Europe, USA and Australia. (author)

  7. X-rays individual dose assessment using TLD dosimeters

    International Nuclear Information System (INIS)

    Salas, Carlos

    2008-01-01

    This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

  8. TLD audit in radiotherapy in the Czech Republic

    International Nuclear Information System (INIS)

    Kroutilikova, D.; Zackova, H.; Judas, L.

    1998-01-01

    National Radiation Protection Institute in Prague organizes the TLD audit. The aim of the TLD postal audit is to provide control of the clinical dosimetry in the Czech Republic for purposes of state supervision in radiotherapy, to investigate and to reduce uncertainties involved in the measurements of absorbed dose and to improve consistency in dose determination in the regional radiotherapy centers. TLD audit covers absorbed dose measurements under reference conditions for 60 Co and 137 Cs beams, high-energy X-ray and electron beams of of linear accelerators and betatrons. The thermo-luminescence dosemeters are sent regularly to all radiotherapy centers. Absorbed dose measures by the TLD is compared to absorbed dose stated by radiotherapy center. Encapsulated LiF:Mg, Ti powder is used for the measurement. Deviation of 3% between stated and TLD measured dose is considered for photons and ±5% for electron beams. First TLD audit was started in 1997. A total of 135 beams was checked. There were found seven major deviations (more than ±6%), which were very carefully investigated. Medical Physicists from these departments reported a set-up mistake. However, at most of those hospitals with major deviations, an in situ audit in details was made soon after TLD audit. There were found discrepancies of clinical dosimetry but also bad technical state of some of the irradiation units. In 1998, second course TLD audit was started. No major deviation was found. Regular TLD audit seems to be a good way to eliminate big mistakes in the basic clinical dosimetry. Repeated audit in the regional radiotherapy centers that had major deviation during the first audit exhibited improvement of their dosimetry. It is intended to broaden the method and to control also beam parameters by means of a multi-purpose phantom. (authors)

  9. JAPANESE READERS (TITLE SUPPLIED).

    Science.gov (United States)

    THREE JAPANESE READERS ARE PRESENTED WHICH CONTAIN VOCABULARY, NOTES, AND DRILL SENTENCES. THE THREE READERS--(1) ARU SARARIIMAN NO ITI-NITI, (2) OTOOSAN WA KAMI-SAMA, AND (3) ARU GAKUSEI NO HANNITI--ARE WRITTEN IN THE ROMAJI ALPHABET. EACH READER HAS A VOCABULARY LISTING WITH ENGLISH EXPLANATIONS AND DRILL SENTENCES. AN ENGLISH WORD DEFINITION…

  10. Measurement of annual dose on porcelain using surface TLD method

    International Nuclear Information System (INIS)

    Xia Junding; Wang Weida; Leung, P.L.

    2001-01-01

    In order to improve accuracy of TL authentication test for porcelain, a method of measurement of annual dose using ultrathin (CaSO 4 :Tm) dosage layer on porcelain was studied. The TLD was placed on the part of porcelain without glaze. A comparison of measurement of annual dose for surface TLD, inside TLD and alpha counting on porcelain was made. The results show that this technique is suitable for measuring annual dose and improving accuracy of TL authentication test for both porcelain and pottery

  11. A digital reader for condenser ionization chambers

    International Nuclear Information System (INIS)

    Stuermer, K.

    1978-01-01

    A reader for condenser chambers is described which has a completely automatic reading/charging operation, a modern digital readout presentation, and two full decades of exposure readout for each dosimeter type. The calibration and operation of the instrument are given

  12. TLD postal dose quality audit service for Co-60 beams in reference conditions in Cuba

    International Nuclear Information System (INIS)

    Gutierrez Lores, S.; Walwyn Salas, G.; Alonso Villanueva, G.

    2008-01-01

    This report presents the methodology and experience of the Cuban's Secondary Standard Dosimetry Laboratory for the implementation of postal dose quality audits service for Co-60 beams in reference conditions, using TLDs. Under coordinated research project (Contract 10794) were bought (TLD -100) Tl rods type JR 1152F made in China, with dimensions of 6 mm x 1 mm x 1 mm. All of these rods were identified individually with a consecutive number made over one of its sides, using a fine tip of graphite. The method used to determinate the individual sensibility of the TL detectors was: irradiating a group of them, with the same history of irradiation and readout (100 rods approximately), four serial times in the same geometrical conditions, to read them out and to attribute to each of them a sensitivity factor. This sensitivity factor is equal to average for the 4 cycle of irradiation and readout of the quote between the TL readout from dosimeter i and the mean of all values for each cycle. The TLD signal was read using HARSHAW 2000C/B reader. The results obtained in the external verification of the accuracy of the dose determination by the TLD system were performed in cooperation with IAEA Dosimetry Laboratory at Seibersdorf in different years are shown, the results obtained of the quality audits carried out to the different services of radiotherapy of the country are analysed also. The quality audits are an useful tool for the improvement of the accuracy in the dosimetry of clinical beams of radiotherapy with Co-60, contributing this way to the improvement of the life quality to cancer patients of the Cuban system of health. (author)

  13. TLD audit in the radiotherapy at the national level

    International Nuclear Information System (INIS)

    Kroutilikova, D.; Zackova, H.; Novotny, J.; Pridal, I.

    1998-01-01

    Czech legislation requires that all radiotherapy departments undertake quality independent audit annually. An authorized auditing group was created as a body of the National Radiation Protection Institute. It has been decided that TLD postal audit combined with film dosimetry would alternate with in situ audit every two or three years. For this, a local TLD measuring network has been established. The methods applied in the TLD audit were taken from EROPAQ and EURAQA projects in 1996 and modified to comply with Czech local circumstances. First TLD audits were started in February 1997. During the February to September period, 60 beams were checked: 26 Co-60 beams, 10 Cs-137 beams, 15 X-ray beams, and 9 electron beams. Details of the measurements and their results are given. (P.A.)

  14. Dosimetric characteristics of a TLD dosemeter with extremities; Caracteristicas dosimetricas de un dosimetro TLD de extremidades

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Diaz B, E.; Lien V, R. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo.Postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

    1999-07-01

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm{sup 3} covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  15. TLD Postal service for quality audits of beams of Co-60 in reference conditions in Cuba

    International Nuclear Information System (INIS)

    Gutierrez L, S.; Walwyn S, G.; Alonso V, G.

    2006-01-01

    Purpose: To describe the methodology and experience of the Secondary Laboratory of Dosimetric Calibration of Cuba in the establishment of the TLD Postal Service for quality audits of beams of Co-60 in reference conditions. Materials and methods: Through the Coordinated Project of Research (Contract 10794) its was bought 200 solid thermoluminescent detectors of LiF: Mg, Ti (TLD-100) in micro bars form with dimensions of 6 x 1 x 1 mm and of the JR 1152F type manufactured in China. All these detectors were identified individually with a serial number on one of its faces, using a graphite fine sheet. Those detectors for its irradiation are introduced in cylindrical plastic capsules developed and used by the International Atomic Energy Agency (IAEA) in the Audit Postal Service of Dose IAEA/WHO, the capsules have one cavity equal to 3 mm for that is necessary to recover this cavity with a fine plastic tube so that the detectors remain immobile during the irradiation. The method used to determine the individual sensitivity of the thermoluminescent detectors is: to irradiate a detectors group (100 micro bars) 4 times in those same geometric conditions, with the same irradiation history and reading, then it is determine for each detector a sensitivity factor equal to the average of those readings obtained for the 4 irradiation cycles for each i detector among the average of all the reading values obtained during the 4 cycles. The thermoluminescent signal is obtained with a Harshaw 2000C/B reader manual. Results: The satisfactory results obtained in the verification of the calibration of the TLD system, using the reference irradiation service of the Seibersdorf Dosimetry Laboratory of the IAEA in three different years are shown. The results of the audits carried out to the different radiotherapy services of the country in different years are also presented. Conclusions: The experience with the detectors acquired in the project demonstrates that with an appropriate

  16. QA Programme of the TLD laboratory of the University of Costa Rica: IEC 61066 testing

    International Nuclear Information System (INIS)

    Mora, Patricia; Porras Chaverria, Mariela

    2008-01-01

    The Thermoluminescence Personal Dosimetry Laboratory of the University of Costa Rica provides dose measurements for around 90% of occupational radiation workers in the country. The assessment of doses to workers routinely exposed to external sources of radiation constitutes an integral part of any radiation protection programme and helps national authorities to ensure acceptably safe and satisfactory radiological conditions in workplaces. Harshaw Readers Model 4000 and 4500, dosimeter holders Type 8814 with TLD-100 in 0110 cards and loose TLD-100 chips are used to monitor personal dose equivalent, Hp(10) and Hp(0.07). In order to provide a reliable measurement of the operational quantities, a study was undertaken to verify the fulfillment of international requirements in our system (Model 4500 with cards) against the Thermoluminescence dosimetry systems for personal and environmental monitoring CEI IEC 61066 (1991 -2012). The type tests performed were nine in total: batch homogeneity, reproducibility, linearity, detection threshold, effect of climate conditions on reader, effect of light exposure on dosimeters, isotropy, transient voltage and dropping on dosimeters. A Cesium-137 source was used to irradiate the dosimeters and all procedures follow the indications given on the standard. Results showed that all IEC criteria were met by our Laboratory. Acceptable uncertainties were also studied under the ICRP recommendations; the analysis of the Trumpet Curve was done with satisfactory results (for doses above 0.5 mSv; quotient of measure to real dose less than 3%). For purposes of accreditation (ISO/IEC 17025:2005) and performance testing this work is very relevant since the University of Costa Rica wants to establish a solid individual monitoring programme for external radiation exposure that will provide users, registrants, licensees and regulatory bodies with information that can be used for the optimization of protection and dose limitation of Costa Rican workers

  17. Texts and Readers.

    Science.gov (United States)

    Iser, Wolfgang

    1980-01-01

    Notes that, since fictional discourse need not reflect prevailing systems of meaning and norms or values, readers gain detachment from their own presuppositions; by constituting and formulating text-sense, readers are constituting and formulating their own cognition and becoming aware of the operations for doing so. (FL)

  18. Measurement of TLD Albedo response on various calibration phantoms

    International Nuclear Information System (INIS)

    Momose, T.; Tsujimura, N.; Shinohara, K.; Ishiguro, H.; Nakamura, T.

    1996-01-01

    The International Commission on Radiation Units and Measurements (ICRU) has recommended that individual dosemeter should be calibrated on a suitable phantom and has pointed out that the calibration factor of a neutron dosemeter is strongly influenced by the the exact size and shape of the body and the phantom to which the dosemeter is attached. As the principle of an albedo type thermoluminescent personal dosemeter (albedo TLD) is essentially based on a detection of scattered and moderated neutron from a human body, the sensitivity of albedo TLD is strongly influenced by the incident neutron energy and the calibration phantom. (1) Therefore for albedo type thermoluminescent personal dosemeter (albedo TLD), the information of neutron albedo response on the calibration phantom is important for appropriate dose estimation. In order to investigate the effect of phantom type on the reading of the albedo TLD, measurement of the TLD energy response and angular response on some typical calibration phantoms was performed using dynamitron accelerator and 252 Cf neutron source. (author)

  19. TLD array for precise dose measurements in stereotactic radiation techniques

    International Nuclear Information System (INIS)

    Ertl, A.; Kitz, K.; Griffitt, W.; Hartl, R.F.E.; Zehetmayer, M.

    1996-01-01

    We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. This TLD array may be useful for phantom or tissue model studies on the spatial dose distribution in confined radiation targets as used in stereotactic radiotherapy. (author)

  20. Data processing of personnel exposure in TLD and film systems

    International Nuclear Information System (INIS)

    Lerner, A.; Liav, N.; Eisen, Y.

    1979-01-01

    The program for the processing and storage of data on the personnel irradiation exposure in Israel is built on the data base of the Weizmann Institute of Science; it is a general program suitable for both TLD and film dosimetry. The TSO system helped bring up-to-date the data of the various collections in an interactive way. The introduction of the TLD dosemeters in the badge service required certain changes in the thinking line - this because the TLD being a personal dosemeter is returned into service after having been deciphered. This demands following up the dosemeter when the worker moves from unit to unit or after he had finished his work. The program takes into account the internal exposures,too and conforms to the new recommendation published in ICRP-26. (B.G.)

  1. Positional glow curve simulation for thermoluminescent detector (TLD) system design

    International Nuclear Information System (INIS)

    Branch, C.J.; Kearfott, K.J.

    1999-01-01

    Multi- and thin element dosimeters, variable heating rate schemes, and glow-curve analysis have been employed to improve environmental and personnel dosimetry using thermoluminescent detectors (TLDs). Detailed analysis of the effects of errors and optimization of techniques would be highly desirable. However, an understanding of the relationship between TL light production, light attenuation, and precise heating schemes is made difficult because of experimental challenges involved in measuring positional TL light production and temperature variations as a function of time. This work reports the development of a general-purpose computer code, thermoluminescent detector simulator, TLD-SIM, to simulate the heating of any TLD type using a variety of conventional and experimental heating methods including pulsed focused or unfocused lasers with Gaussian or uniform cross sections, planchet, hot gas, hot finger, optical, infrared, or electrical heating. TLD-SIM has been used to study the impact on the TL light production of varying the input parameters which include: detector composition, heat capacity, heat conductivity, physical size, and density; trapped electron density, the frequency factor of oscillation of electrons in the traps, and trap-conduction band potential energy difference; heating scheme source terms and heat transfer boundary conditions; and TL light scatter and attenuation coefficients. Temperature profiles and glow curves as a function of position time, as well as the corresponding temporally and/or spatially integrated glow values, may be plotted while varying any of the input parameters. Examples illustrating TLD system functions, including glow curve variability, will be presented. The flexible capabilities of TLD-SIM promises to enable improved TLD system design

  2. The StorySpinner Sculptural Reader

    OpenAIRE

    Hooper, Clare; Weal, Mark

    2005-01-01

    This demo is of a hypertext reading system called StorySpinner. It follows the sculptural hypertext methodology and has been used as a test bed for experimenting with the authoring of narrative flow in automatically generated stories. Readers are able to select and read one of two available stories. Reading a story involves selecting tarot cards which are mapped to chunks of story text based on possible interpretations of the cards and information concerning current story state.

  3. Direct measurement of annual β dose using TLD on porcelain

    International Nuclear Information System (INIS)

    Leung, P.L.; Stokes, M.J.; Xia Junding; Wang Weida; Zhou Zhixin

    1999-01-01

    In order to improve accuracy of TL authentication test for porcelain, a method of direct measurement of annual β dose using ultrathin TLD (CaSO 4 :Tm) on porcelain was studied. Since the TLD was placed into a hole left after sampling for the TL measurement, the method will not cause any new damage to the studied object. The results show that the technique is suitable for measuring annual β dose and improving accuracy of TL authentication test for both porcelain and pottery

  4. Differences in TLD 600 and TLD 700 glow curves derived from distict mixed gamma/neutron field irradiations

    International Nuclear Information System (INIS)

    Cavalieri, Tassio A.; Castro, Vinicius A.; Siqueira, Paulo T.D.

    2013-01-01

    In Neutron Capture Therapy, a thermal neutron beam shall impinge on a specific nuclide, such as 10 B, to promote a nuclear reaction which releases the useful therapeutic energy. A nuclear reactor is usually used as the neutron source, and therefore field contaminants such as gamma and high energy neutrons are also present in the field. However, mixed field dosimetry still stands as a challenge in some cases, due to the difficulty to experimentally discriminate the dose from each field component. For the mixed field dosimetry, the International Commission on Radiation end Units (ICRU) recommends the use of detector pairs with different responses for each beam component. The TLD 600/700 pair meets this need, because these LiF detectors have different Li isotopes concentration, with distinct thermal neutron responses because 6 Li presents a much higher neutron capture cross section than does 7 Li for low energy neutrons. TLD 600 is 6 Li enriched while TLD 700 is 7 Li enriched. However, depending on the neutron spectrum presented in the mixed field, TLD 700 response to thermal neutrons cannot be disregarded. This work aims to study the difference in TLD 600 and TLD 700 glow curves when these TLDs are submitted to mixed fields of different energy spectra and components balance. The TLDs were irradiated in a pure gamma source, and in mixed fields from an AmBe sealed source and from the IPEN/MB-01 reactor. These TLDs were read and had their two main dosimetric regions analyzed to observe the differences in the glow curves of these TLDs in each irradiation. Field components discrimination was achieved through Monte Carlo simulations run with MCNP radiation transport code. (author)

  5. Periodicity of TLD badge personnel monitoring service in India

    International Nuclear Information System (INIS)

    Kher, R.K.; Joshi, V.D.; Kaushik, Aruna; Sharma, Amiy; Chatterjee, S.

    2003-01-01

    The periodicity of an individual monitoring service is an important aspect. Presently minimum period for TLD badge service is maintained as 'calendar month' and choice of quarterly service is also offered. The periodicity of the TLD service for a given category/application type of institution, is to be fixed taking into account level of average occupational doses in all or typical institutions of given category and other information indicating the status of safety and possible fluctuations of exposure levels and potential for overexposure cases. This paper presents the status on the periodicity of TLD Badge Service as is evolved and adopted for the four broad categories i.e. DAE (Nuclear Fuel Cycle) Institutions, Industrial, Medical, Research institutions. It is concluded that quarterly service is a convenient option for institution categories where type of work/workload, and work practices are such that occupational exposures could be normally kept below about one mSv or so in the monitoring period, average annual dose less than 1 mSv and persons receiving annual dose >10 mSv is less than 1% of total in the category. Also, the judicious use of the flexibility in the periodicity of TLD Badge service would help (i) to keep the monitoring related workload to the optimum for the monitoring units and (ii) to keep the expenses incurred by the institution towards monitoring to the minimum without sacrificing radiation safety (iii) to focus the extra monitoring efforts on the applications/situations requiring improvement in radiation safety. (author)

  6. Measuring thermo-luminescence efficiency of TLD-2000 detectors to different energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wei Min; Chen, Bao Wei; Han, Yi; Yang, Zhong Jian [China Institute for Radiation Protection, Taiyuan (China)

    2016-06-15

    As an important detecting device, TLD is a widely used in the radiation monitoring. It is essential for us to study the property of detecting element. The aim of this study is to calculate the thermo-luminescence efficiency of TL elements. A batch of thermo-luminescence elements were irradiated by the filtered X-ray beams of average energies in the range 40-200 kVp, 662 keV {sup 137}Cs gamma rays and then the amounts of lights were measured by the TL reader. The deposition energies in elements were calculated by theory formula and Monte Carlo simulation. The unit absorbed dose in elements by photons with different energies corresponding to the amounts of lights was calculated, which is called the thermo luminescent efficiency (η(E)). Because of the amounts of lights can be calculated by the absorbed dose in elements multiply η(E), the η(E) can be calculated by the experimental data (the amounts of lights) divided by absorbed dose. The deviation of simulation results compared with theoretical calculation results were less than 5%, so the absorbed dose in elements was calculated by simulation results in here. The change range of η(E) value, relative to 662 keV {sup 137}Cs gamma rays, is about 30% in the energy range of 33 keV to 662 keV, is in accordance by the comparison with relevant foreign literatures. The η(E) values can be used for updating the amounts of lights that are got by the direct ratio assumed relations with deposition energy in TL elements, which can largely reduce the error of calculation results of the amounts of lights. These data can be used for the design of individual dosimeter which used TLD-2000 thermo-luminescence elements, also have a certain reference value for manufacturer to improve the energy-response performance of TL elements by formulation adjustment.

  7. Introducing 2D barcode on TLD cards - a step towards automation in personnel monitoring

    International Nuclear Information System (INIS)

    Ajoy, K.C.; Dhanasekaran, A.; Annalakshmi, O; Rajagopal, V.; Santhanam, R.; Jose, M.T.

    2018-01-01

    As part of personnel monitoring services, TLD lab, RSD, IGCAR issues and receives large numbers of TLD cards every month, for use by occupational workers belonging to various hot facilities at Kalpakkam. Considering the nature of the work being manual, routine, labour intensive and being prone for human errors, introducing automation would be necessary at the TLD lab as well as at the user facility. This requires identification of the individual components of the TLD and embed them with unique identification for the system to accomplish the task. The paper discusses the automation part related to the TLD cards

  8. DEAFNESS, RETELLING AND READER FOMATION

    Directory of Open Access Journals (Sweden)

    José Marcos Rosendo de Souza

    2016-07-01

    Full Text Available Research on formation of readers has raised some discussions and change of atitudes, to the development of full readers. But, the methodologies that strive for proficiency of Deaf readers there are scarse. We intend to discuss in this article the formation of a reader Deaf through from an interventional research, with cognitive approach. The reader formation of Deaf will be possible with appropriate method to their peculiarities.

  9. Our Readers Write ...

    Indian Academy of Sciences (India)

    IAS Admin

    This concerns the article 'Ashoke Sen and S-duality'. The article omits an important fact: there is absolutely no experimental evidence for string theory. Without this information, readers may think they are reading about established facts, not speculation. A string theorist, Witten, was awarded a Fields Medal, which shows that ...

  10. Bytes, Books and Readers

    DEFF Research Database (Denmark)

    Rasmussen, Krista Stinne Greve

    2016-01-01

    In diesem Beitrag werden Ergebnisse aus der Dissertation der Autorin Bytes, Books, and Readers. A Historical Analysis of the Transition from Printed to Digital Scholarly Editions Focusing on ‘The Writings of Søren Kierkegaard’ (2015) vorgestellt. Dabei wird dem Wechselverhältnis zwischen der...

  11. Growing Young Gifted Readers

    Science.gov (United States)

    Wood, Patricia F.

    2009-01-01

    There is great pressure on parents to teach children to read as early as possible. In reality, precocious (early advanced) readers seem to almost master the skill on their own, without the assistance of highly touted, commercially available programs. The 18-month-old toddler who names the letters on alphabet blocks; or the 26-month-old who can…

  12. Dosimetric quality control in radiotherapy using TLD methodology

    International Nuclear Information System (INIS)

    Saravi, M.C.; Kessler, C.; Alvarez, P.E.; Feld, D.B.

    2002-01-01

    In the frame of the IAEA Co-ordinated Research Project 'Development of a Quality Assurance Program for Radiation Therapy Dosimetry in Developing Countries' a Dosimetric Quality Control Group was set up in Argentina in 1996, to develop a program in order to improve radiotherapy in the country. Nowadays, this Group, briefly called External Audit Group (EAG), is composed by the national Secondary Standard Dosimetry Laboratory (SSDL), which has the responsibility for dose determinations, traceability to international dosimetry chain and TLD measurements, and two Medical Physicists from CNEA who are working at the Oncology Hospital 'Marie Curie' in Buenos Aires. The present paper reports the activities performed by the EAG with external high energy photon beams in reference conditions and the results of two pilot studies on cobalt 60 beams in non-reference conditions. The first step of the program was to update the existing data base about the radiotherapy centres operating in the country. A form was sent to each of them in order to obtain basic information about their staff, number and type of treatment machines, brachytherapy sources, measuring devices, beam calibration, treatment planning system, simulator and other relevant data. 90 radiotherapy centres were registered in the EAG data base. Forms were completed by 75/90 centres. There are nowadays 69 cobalt 60 units and 42 LINACs operating in the country (18/42 LINACs producing high energy X ray and electron beams). EAG deals with measurements performed with mailed TLD irradiated at radiotherapy centres. Internal quality control on our TLD system is made during each audit by means of reference capsules irradiated by IAEA; external controls consist in blind tests performed by IAEA once a year. The correction factor, K en , determined at our SSDL for high energy X-rays was checked with the collaboration of IAEA and Prague National Radiation Protection Institute (PNRPI) by means of a blind test. Results for 4 MV, 6 MV

  13. Environmental monitoring system with TLD; Sistema de monitoreo ambiental con TLD

    Energy Technology Data Exchange (ETDEWEB)

    Aguerre, L.; Carelli, J.; Gregori, B. [Autoridad Regulatoria Nuclear Argentina (Argentina)]. e-mail: laguerre@cae.arn.gov.ar

    2006-07-01

    Presently work the methodology used by the Laboratory of Thermoluminescent Dosimetry (TLD) of the Nuclear Regulatory Authority (RNA) to gauge it system of environmental monitoring in function of the media absorbed dose rate in free air and the environmental dose equivalent, H{sup *}(10), according to the recommendation ICRU Report 47 is described. It was studied the response of the environmental dosemeter (DA) in fields of photonic radiation of energies W60, Wl 10, W200 and {sup 137} Cs. The irradiations were carried out following the recommendations of the standard ISO:4037. It was analyzed the response in the DA of the detectors LiF: Mg, Ti and CaF{sub 2}: Dy for the different radiation qualities and the relative response at {sup 137} Cs of both. The methodology used in the evaluation of the dose includes: the correction of the readings of both detectors by fading, gotten experimentally, the witness of transfers, the energy answer and the value of the zero. The dose is calculated applying the average pondered in uncertainty of the dose obtained for each type of detector. Its were analyzed and calculated the uncertainties that affect to the measurement following the recommendation of the Argentine standard IRAM 35050. The detection limit of the absorbed dose rate in free air of this system it is 3.5 n Gy/h for a period of sampling of 3 months. With this detection limit environmental dose equivalent rates of the order of 70 n Sv/h are measured with an expanded uncertainty of the order of 10% with a cover factor k = 2. (Author)

  14. Photon energy response of an aluminum oxide TLD environmental dosimeter

    International Nuclear Information System (INIS)

    Olsher, R.H.

    1992-01-01

    Because of aluminum oxide's significant advantage in sensitivity (about a factor of 30) over LiF, minimal fading characteristics and ease of processing, aluminum oxide thermoluminescent dosimeters (TLDS) are being phased in at Los alamos for environmental monitoring of photon radiation. The new environmental dosimeter design consists of a polyethylene holder, about 0. 5 cm thick, loaded with a stack of four aluminum oxide TLD chips, each 1 mm thick and 5 mm in diameter. As part of the initial evaluation of the new design, the photon energy response of the dosimeter was calculated over the range from 10 keV to 1 MeV. Specific goals of the analysis included the determination of individual chip response in the stack, assessment of the response variation due to TLD material (i.e., LiF versus A1 2 O 3 ), and the effect of copper filtration in flattening the response

  15. Quality Assurance and Quality Control in TLD Measurement

    International Nuclear Information System (INIS)

    Bhuiyan, S.I.; Qronfla, M.M.; Abulfaraj, W.H.; Kinsara, A.A.; Taha, T.M.; Molla, N.I.; Elmohr, S.M.

    2008-01-01

    TLD technique characterized by high precision and reproducibility of dose measurement is presented by addressing pre-readout annealing, group sorting, dose evaluation, blind tests, internal dose quality audit and external quality control audits. Two hundred and forty TLD chips were annealed for 1 hour at 4000 degree C followed by 2 h at 1000 degree C. After exposure of 1 mGy from 90 Sr irradiator TLDs were subjected to pre-readout annealing at 1000 degree C, then readout, sorted into groups each with nearly equal sensitivity. Upon repeating the procedures, TLDs having response >3.5% from group mean were dropped to assuring group stability. Effect of pre-readout annealing has been studied. Series of repeated measurements were conducted to stabilize calibration procedures and DCF generation using SSDL level 137 Cs calibrator, dose master, ionization chambers. Performed internal dose quality audits, blind tests and validated by external QC tests with King Abdulaziz City of Science and Technology

  16. Environmental radiation measurements using TLD in and around AERE, Dhaka

    International Nuclear Information System (INIS)

    Mollah, A.S.; Husain, S.R.; Rahman, M.M.

    1986-01-01

    The external background radiation level in and around the Atomic Energy Research Establishment (AERE) in Dhaka has been measured. The measurements were performed using lithium fluoride (LiF) thermoluminescence dosemeters (TLD-100) at 32 locations, all one metre above the ground. The annual average dose rate measured in the AERE environs was 1.74+-0.23 mGy.y -1 in air, based on analysis of thermoluminescence dosemeter data collected from 1982 to 1984. (author)

  17. Meeting regulatory standards with BeO ceramic TLD

    International Nuclear Information System (INIS)

    Gammage, R.B.; Christian, D.J.

    1978-01-01

    Measurements of exposures below 1 mR are possible with BeO ceramic TLD by signal recording that discriminates against an interfering pyroelectric incandescence. Performance under environmental monitoring conditions is considered in light of current regulatory criteria. Factors such as reproducibility and batch uniformity are satisfactory. An anomalous energy dependence causes an over-response that will probably require use of an energy compensation shield

  18. TLD Postal service for quality audits of beams of Co-60 in reference conditions in Cuba; Servicio Postal TLD para auditorias de calidad de haces de Co-60 en condiciones de referencia en Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez L, S.; Walwyn S, G.; Alonso V, G. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, C.P. 11300, C. Habana (Cuba)]. e-mail: stefan@cphr.edu.cu

    2006-07-01

    Purpose: To describe the methodology and experience of the Secondary Laboratory of Dosimetric Calibration of Cuba in the establishment of the TLD Postal Service for quality audits of beams of Co-60 in reference conditions. Materials and methods: Through the Coordinated Project of Research (Contract 10794) its was bought 200 solid thermoluminescent detectors of LiF: Mg, Ti (TLD-100) in micro bars form with dimensions of 6 x 1 x 1 mm and of the JR 1152F type manufactured in China. All these detectors were identified individually with a serial number on one of its faces, using a graphite fine sheet. Those detectors for its irradiation are introduced in cylindrical plastic capsules developed and used by the International Atomic Energy Agency (IAEA) in the Audit Postal Service of Dose IAEA/WHO, the capsules have one cavity equal to 3 mm for that is necessary to recover this cavity with a fine plastic tube so that the detectors remain immobile during the irradiation. The method used to determine the individual sensitivity of the thermoluminescent detectors is: to irradiate a detectors group (100 micro bars) 4 times in those same geometric conditions, with the same irradiation history and reading, then it is determine for each detector a sensitivity factor equal to the average of those readings obtained for the 4 irradiation cycles for each i detector among the average of all the reading values obtained during the 4 cycles. The thermoluminescent signal is obtained with a Harshaw 2000C/B reader manual. Results: The satisfactory results obtained in the verification of the calibration of the TLD system, using the reference irradiation service of the Seibersdorf Dosimetry Laboratory of the IAEA in three different years are shown. The results of the audits carried out to the different radiotherapy services of the country in different years are also presented. Conclusions: The experience with the detectors acquired in the project demonstrates that with an appropriate

  19. Indoor gamma radiation monitoring In Rawalpindi, Pakistan using TLD100

    International Nuclear Information System (INIS)

    Azam, Sana; Tufail, Muhammad; Sohail, Muhammad

    2008-01-01

    Full text: Natural radioactivity originates from extraterrestrial sources as well as from radioactive elements in earth's crust. The amount of radioactivity varies from place to place and with altitude. The aim of this study was to observe the indoor radiation level in Rawalpindi using TLD. For this purpose LiF:Mg:Ti (TLD100) chips were used. Chips were annealed and then calibrated using different sources and the calibration factor obtained by using Cs137 source was selected for dose estimation. Its value was 0.1403 μGy/TL response. Rawalpindi categorized into six regions. In each region, 5 cemented houses were selected and TLD 100 chips were placed at a distance of 0.5 m from ground the level. Chips were properly covered to protect them from ultraviolet light and moisture and were placed for three months. The average annual indoor dose rate for Rawalpindi was estimated to be 392.105μGy/yr and average dose to be 97.65μGy. Therefore, the effective dose for population of Rawalpindi from indoor gamma radiation was estimated to be 313.68μSv/yr using an indoor occupancy factor of 80%. (author)

  20. Centralized TLD service and record keeping in Canada

    International Nuclear Information System (INIS)

    Grogan, D.; Ashmore, J.P.; Bradley, R.P.

    1979-01-01

    A centralized automated TLD service operated by the Department of National Health and Welfare went into operation in May 1977 to monitor radiation workers throughout Canada. Twenty-thousand employees from a wide range of disciplines are enrolled and the number will be increased to fifty thousand by September l978. A prototype of the system, operational from September 1976 to May 1977 for three-thousand people, has already been described. A description of technical and operational highlights is presented as well as a description of problems experienced during the first full year of operation. Details of costs, conversion logistics, operational performance and technical problems are included. A comparison of the advantages and disadvantages of changing from film dosimetry to TLD in a nationwide context is detailed. The dose meter read-out unit is interfaced, through video terminals, with a time-sharing computer system programmed to provide direct access to the Canadian National Dose Registry. Details of this linkage are described, as are the computer programmes for routine processing of raw batch data. The centralized TLD service interactively linked with the National Dose Registry provides a comprehensive occupational monitoring programme invaluable for regulatory control. (author)

  1. Self-shielding factors for TLD-600 and TLD-100 in an isotropic flux of thermal neutrons

    International Nuclear Information System (INIS)

    Horowitz, Y.S.; Dubi, A.; Ben Shahar, B.

    1976-01-01

    The applications of lithium fluoride thermoluminescent dosemeters in mixed n-γ environments, and the dependence of LiF-TL on linear energy transfer are both topics of current interest. Monte Carlo calculations have therefore been carried out to determine the thermal neutron absorption probability (and consequently the self-shielding factor) for an isotropic flux of neutrons impinging on different sized cylindrical samples of LiF TLD-100 and TLD-600. The calculations were performed for cylinders of radius up to 10 cm and heights of 0.1 to 1.5 cm. The Monte Carlo results were found to be significantly different from the analytic calculations for infinitely long cylinders, but, as expected, converged to the same value for (r/h) << 1. (U.K.)

  2. Crash course in readers' advisory

    CERN Document Server

    Orr, Cynthia

    2014-01-01

    One of the key services librarians provide is helping readers find books they'll enjoy. This ""crash course"" will furnish you with the basic, practical information you need to excel at readers' advisory (RA) for adults and teens.

  3. Neutron dose measurements of Varian and Elekta linacs by TLD600 and TLD700 dosimeters and comparison with MCNP calculations.

    Science.gov (United States)

    Nedaie, Hassan Ali; Darestani, Hoda; Banaee, Nooshin; Shagholi, Negin; Mohammadi, Kheirollah; Shahvar, Arjang; Bayat, Esmaeel

    2014-01-01

    High-energy linacs produce secondary particles such as neutrons (photoneutron production). The neutrons have the important role during treatment with high energy photons in terms of protection and dose escalation. In this work, neutron dose equivalents of 18 MV Varian and Elekta accelerators are measured by thermoluminescent dosimeter (TLD) 600 and TLD700 detectors and compared with the Monte Carlo calculations. For neutron and photon dose discrimination, first TLDs were calibrated separately by gamma and neutron doses. Gamma calibration was carried out in two procedures; by standard 60Co source and by 18 MV linac photon beam. For neutron calibration by (241)Am-Be source, irradiations were performed in several different time intervals. The Varian and Elekta linac heads and the phantom were simulated by the MCNPX code (v. 2.5). Neutron dose equivalent was calculated in the central axis, on the phantom surface and depths of 1, 2, 3.3, 4, 5, and 6 cm. The maximum photoneutron dose equivalents which calculated by the MCNPX code were 7.06 and 2.37 mSv.Gy(-1) for Varian and Elekta accelerators, respectively, in comparison with 50 and 44 mSv.Gy(-1) achieved by TLDs. All the results showed more photoneutron production in Varian accelerator compared to Elekta. According to the results, it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry inside the linac field due to high photon flux, while MCNPX code is an appropriate alternative for studying photoneutron production.

  4. Developmental roles of the BMP1/TLD metalloproteinases.

    Science.gov (United States)

    Ge, Gaoxiang; Greenspan, Daniel S

    2006-03-01

    The astacin family (M12A) of the metzincin subclan MA(M) of metalloproteinases has been detected in developing and mature individuals of species that range from hydra to humans. Functions of this family of metalloproteinase vary from digestive degradation of polypeptides, to biosynthetic processing of extracellular proteins, to activation of growth factors. This review will focus on a small subgroup of the astacin family; the bone morphogenetic protein 1 (BMP1)/Tolloid (TLD)-like metalloproteinases. In vertebrates, the BMP1/TLD-like metalloproteinases play key roles in regulating formation of the extracellular matrix (ECM) via biosynthetic processing of various precursor proteins into mature functional enzymes, structural proteins, and proteins involved in initiating mineralization of the ECM of hard tissues. Roles in ECM formation include: processing of the C-propeptides of procollagens types I-III, to yield the major fibrous components of vertebrate ECM; proteolytic activation of the enzyme lysyl oxidase, necessary to formation of covalent cross-links in collagen and elastic fibers; processing of NH2-terminal globular domains and C-propeptides of types V and XI procollagen chains to yield monomers that are incorporated into and control the diameters of collagen type I and II fibrils, respectively; processing of precursors for laminin 5 and collagen type VII, both of which are involved in securing epidermis to underlying dermis; and maturation of small leucine-rich proteoglycans. The BMP1/TLD-related metalloproteinases are also capable of activating the vertebrate transforming growth factor-beta (TGF-beta)-like "chalones" growth differentiation factor 8 (GDF8, also known as myostatin), and GDF11 (also known as BMP11), involved in negative feedback inhibition of muscle and neural tissue growth, respectively; by freeing them from noncovalent latent complexes with their cleaved prodomains. BMP1/TLD-like proteinases also liberate the vertebrate TGF

  5. IAEA/WHO TLD postal dose audit service and high precision measurements for radiotherapy level dosimetry

    International Nuclear Information System (INIS)

    Izewska, J.; Bera, P.; Vatnitsky, S.

    2002-01-01

    Since 1969 the International Atomic Energy Agency, together with the World Health Organization, has performed postal TLD audits to verify calibration of radiotherapy beams in developing countries. The TLD programme also monitors activities of Secondary Standard Dosimetry Laboratories (SSDLs). The programme has checked approximately 4000 clinical beams in over 1100 hospitals, and in many instances significant errors have been detected in the beam calibration. Subsequent follow-up actions help to resolve the discrepancies, thus preventing further mistreatment of patients. The audits for SSDLs check the implementation of the dosimetry protocol in order to assure proper dissemination of dosimetry standards to the end-users. The TLD audit results for SSDLs show good consistency in the basic dosimetry worldwide. New TLD procedures and equipment have recently been introduced by the IAEA that include a modified TLD calibration methodology and computerised tools for automation of dose calculation from TLD readings. (author)

  6. PC-based car license plate reader

    Science.gov (United States)

    Hwang, Chung-Mu; Shu, Shyh-Yeong; Chen, Wen-Yu; Chen, Yie-Wern; Wen, Kuang-Pu

    1992-11-01

    A car license plate reader (CLPR) using fuzzy inference and neural network algorithm has been developed in Industrial Technology Research Institute (ITRI) and installed in highway toll stations to identify stolen cars. It takes an average of 0.7 seconds to recognize a car license plate by using a PC with 80486-50 CPU. The recognition rate of the system is about 97%. The techniques of CLPR include vehicle sensing, image grab control, optic pre- processing, lighting, and optic character recognition (OCR). The CLPR can be used in vehicle flow statistics, the checking of stolen vehicles, automatic charging systems in parking lots or garage management, and so on.

  7. Cognitive Development in Early Readers.

    Science.gov (United States)

    Briggs, Chari; Elkind, David

    Some studies of early readers are discussed. It is pointed out that study of early readers has relevance for practical and theoretical issues in psychology and education. Of interest in this document are the following questions: (1) Are there any special talents or traits distinguishing early from non-early readers? (2) Do children who read early…

  8. The characteristics of CaF2:Tm crystals (TLD-300) irradiated by electromagnetic radiation

    International Nuclear Information System (INIS)

    Ben-Shachar, B.; Yona, S.; Laichter, Y.; German, U.; Weiser, G.

    1985-09-01

    The main characteristics of the CaF 2 :Tm crystals (TLD-300), as a dosimeter, were measured: the glow curve, sensitivity, linearity, fading and energy dependence for photons, and compared to those of LiF (TLD-100) and CaF 2 :Dy (TLD-200). It was found that CaF 2 :Tm can be used for environmental dosimetry by reading the crystals after four days. (Author)

  9. Scaffolding or Distracting: CD-ROM Storybooks and Young Readers

    Science.gov (United States)

    Pearman, Cathy J.; Chang, Ching-Wen

    2010-01-01

    CD-ROM storybooks, often referred to as electronic texts, e-books, and interactive stories, are learning tools with supplemental features such as automatic reading of text, sound effects, word pronunciations, and graphic animations which support the development of reading skills and comprehension in beginning readers. Some CD-ROM storybooks also…

  10. Study of a method based on TLD detectors for in-phantom dosimetry in BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G. [Dept. of Physics of the Univ., Via Celoria 16, 20133 Milan (Italy); INFN, Natl. Inst. of Nuclear Physics, Via Celoria 16, 20133 Milan (Italy); Klamert, V. [Dept. of Nuclear Eng. of Polytechnic, CESNEF, Via Ponzio 34/3, 20133 Milan (Italy); Agosteo, S. [INFN, Natl. Inst. of Nuclear Physics, Via Celoria 16, 20133 Milan (Italy); Dept. of Nuclear Eng. of Polytechnic, CESNEF, Via Ponzio 34/3, 20133 Milan (Italy); Birattari, C.; Gay, S. [Dept. of Physics of the Univ., Via Celoria 16, 20133 Milan (Italy); INFN, Natl. Inst. of Nuclear Physics, Via Celoria 16, 20133 Milan (Italy); Rosi, G. [FIS-ION, ENEA, Casaccia, Via Anguillarese 301, 00060 Santa Maria di Galeria, Rome (Italy); Scolari, L. [Dept. of Physics of the Univ., Via Celoria 16, 20133 Milan (Italy); INFN, Natl. Inst. of Nuclear Physics, Via Celoria 16, 20133 Milan (Italy)

    2004-07-01

    A method has been developed, based on thermoluminescent dosemeters (TLD), aimed at measuring the absorbed dose in tissue-equivalent phantoms exposed to thermal or epithermal neutrons, separating the contributions of various secondary radiation generated by neutrons. The proposed method takes advantage of the very low sensitivity of CaF{sub 2}:Tm (TLD-300) to low energy neutrons and to the different responses to thermal neutrons of LiF:Mg,Ti dosemeters with different {sup 6}Li percentage (TLD-100, TLD-700, TLD-600). The comparison of the results with those obtained by means of gel dosemeters and activation foils has confirmed the reliability of the method. The experimental modalities allowing reliable results have been studied. The glow curves of TLD-300 after gamma or neutron irradiation have been compared; moreover, both internal irradiation effect and energy dependence have been investigated. For TLD-600, TLD-100 and TLD-700, the suitable fluence limits have been determined in order to avoid radiation damage and loss of linearity. (authors)

  11. Dose reader CD-02

    International Nuclear Information System (INIS)

    Jakowiuk, A.; Kaluska, I.; Machaj, B.

    2005-01-01

    Dose Reader CD-02 is designed for measurement of dose from a long narrow band of dosimetric foil used for check up and control of electron beam dose during sterilization of materials and products on conveyor belt. Irradiated foil after processing (heating) is inserted into foil driving (moving) system and when the foil is moved across focused light beam the absorbed dose is measured and displayed at the same time at computer monitor (in form of a diagram). The absorbed dose is measured on the principle of light attenuation at selected light wavelength (foil absorbance is measured). (author)

  12. Chipless RFID reader architecture

    CERN Document Server

    Karmakar, Nemai Chandra; Kalansuriya, Prasanna

    2013-01-01

    In the era of information communication technology (ICT), radio frequency identification (RFID) has been going through tremendous development. RFID technology has the potential of replacing barcodes due to its large information carrying capacity, flexibility in operations, and applications. The deployment of RFID has been hindered by its cost. However, with the advent of low powered ICs, energy scavenging techniques, and low-cost chipless tags, RFID technology has achieved significant development. This book addresses the new reader architecture, presents fundamentals of chipless RFID systems,

  13. Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading

    International Nuclear Information System (INIS)

    Estrada E, D.

    2002-01-01

    The interest that motivated the realization of this work is the opposing discrepancy among the values of the efficiency thermoluminescent of heavy charged particles (PCP) regarding gamma radiation (η PCP , γ) reported in different works and gathered recently for Horowitz (Ho 01). The measures of relative thermoluminescent efficiency have importance in relation to the dosimetry associated to medical therapy with heavy charged particle. The measurement of η PCP , γ depends of multiple experimental factors. To understand this dependence it was quantified the effect of using different procedures experimental in the estimate of the relative thermoluminescent efficiency of dosemeters TLD-100 (LiF: Ti; Mg) for protons of 3 MeV regarding gamma rays of 60 Co (η PCP , γ), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for (η PCP , γ) inside the interval [0.30, 0.58] for the peak 5 and [0.35, 0.76] for the total thermoluminescent signal (Tl). At the use different equipment, baked and lot are obtained maximum differences of 30%, 12% and 6% respectively in the values of (η PCP , γ) for the peak 5, and 25%, 28% and 7% for the total Tl signal. The changes more significant of 36% and 44% for peak 5 and total signal respectively are obtained when changing the presentation of the dosemeter. As a complementary investigation it was studied the distribution of the Tl signal of each peak in the deconvolution of the curve of brightness with regard to the total signal in exposed dosemeters to high fluence of protons (1x10 10 p/cm 2 ) varying the experimental protocol. It was found that the distribution of the Tl signal has a difference of the order of 5% when changing the used reading team. It was observed that the contribution of the peak 5 regarding the total signal are preserved when changing baked and that it results to be 8% greater for the presentation in dosemeters of 1 x 1 x 1 mm 3

  14. Dosimetric characteristics of a TLD dosemeter with extremities

    International Nuclear Information System (INIS)

    Molina P, D.; Diaz B, E.; Lien V, R.

    1999-01-01

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm 3 covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  15. Dosimetry Measurements around the Angiography Units Using Thermoluminescence Detectors (TLD)

    International Nuclear Information System (INIS)

    Salah El-den, T.; Shahein, A.Y.; Gomaa, M.A.

    2008-01-01

    The thermoluminescent dosimeters (TLDs) are widely used not only in the field of personnel monitoring (dosimetry) service for ionizing radiation to medical, and research communities, but also for measurements of X-rays emitted from different angiography's unit. Measurements ionizing radiation around the bed area during cardiac catheterization procedures using X-rays was measured. TLD Badges used to determine the annual effective doses, the safe distance for the staff to minimize radiation exposure and the effectiveness of shield and used leaded apron. The results indicated that annual effective dose for by angiography cardiac Catheterization room may exceed the limits

  16. NRC TLD Direct Radiation Monitoring Network. Progress report, January-June 1981

    International Nuclear Information System (INIS)

    1982-04-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of 55 NRC-licensed facility sites throughout the country for the first half of 1981. The program objectives, scope, and methodology are given. The TLD system, dosimeter location, data processing scheme, and quality assurance program are outlined

  17. Doses Due to the South Atlantic Anomaly During the Euromir'95 Mission Measured by an On-Board TLD System

    International Nuclear Information System (INIS)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I.; Reitz, G.

    1999-01-01

    During the Euromir'95 mission, a specially designed microprocessor-controlled thermoluminescent detector (TLD) system, called the 'Pille'95', was used by ESA astronaut Thomas Reiter to measure the cosmic radiation dose inside the Mir space station. One of the experiment's objectives was to determine the dose fraction on Mir due to the South Atlantic Anomaly (SAA) on an orbit inclined at 51.6 deg. and at an altitude of about 400 km. Using an hourly measuring period for 170 h in automatic mode, dose components both of galactic (independent of SAA) and SAA origin were determined. It was found that the maximum dose due to crossing the SAA was equal to 55 μGy. Averaging all the measurements it was calculated that the mean dose rate inside the Mir was 12-14 μGy.h -1 , and that half of this value was caused by the SAA. (author)

  18. A TLD dose algorithm using artificial neural networks

    International Nuclear Information System (INIS)

    Moscovitch, M.; Rotunda, J.E.; Tawil, R.A.; Rathbone, B.A.

    1995-01-01

    An artificial neural network was designed and used to develop a dose algorithm for a multi-element thermoluminescence dosimeter (TLD). The neural network architecture is based on the concept of functional links network (FLN). Neural network is an information processing method inspired by the biological nervous system. A dose algorithm based on neural networks is fundamentally different as compared to conventional algorithms, as it has the capability to learn from its own experience. The neural network algorithm is shown the expected dose values (output) associated with given responses of a multi-element dosimeter (input) many times. The algorithm, being trained that way, eventually is capable to produce its own unique solution to similar (but not exactly the same) dose calculation problems. For personal dosimetry, the output consists of the desired dose components: deep dose, shallow dose and eye dose. The input consists of the TL data obtained from the readout of a multi-element dosimeter. The neural network approach was applied to the Harshaw Type 8825 TLD, and was shown to significantly improve the performance of this dosimeter, well within the U.S. accreditation requirements for personnel dosimeters

  19. Influences of scattering radiation in a TLD irradiation room, 2

    International Nuclear Information System (INIS)

    Suzuki, Osamu; Suwa, Shigeo

    1985-01-01

    The influence of scattering radiation (SR) on radiation dose rate (DR) in a TLD irradiation room was assessed. A single SD from a standard TLD apparatus, i.e., an acrylic or aluminum table, was examined. The maximum DR was attained at approximately 80 cm from the radiation source. Energy spectra of SR ranged up to the energy of direct radiation beam. Circular SD at one m from the radiation source, which contributed to DR to the direct radiation beam, was almost homogeneous. SD was large near the irradiation table, and the influence of SD on DR became smaller with SD being vertically farther from the apparatus. The influence of SD on RD to the direct radiation beam became less with an increase in gamma ray energy. At one m from the radiation source, 6 - 7 % of SD contributed to DR to the direct radiation beam for 0.662 MeV of gamma ray. This figure was one half of that with NaI (Tl) scintillation detector. (Namekawa, K.)

  20. Word Processing in Dyslexics: An Automatic Decoding Deficit?

    Science.gov (United States)

    Yap, Regina; Van Der Leu, Aryan

    1993-01-01

    Compares dyslexic children with normal readers on measures of phonological decoding and automatic word processing. Finds that dyslexics have a deficit in automatic phonological decoding skills. Discusses results within the framework of the phonological deficit and the automatization deficit hypotheses. (RS)

  1. The effect of sample/planchet geometry and temperature resolution on the reproducibility of glow curve shapes and precision of dose measurement in LiF-TLD-100 thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Sibony, D.; Horowitz, Y.; Oster, L.

    2014-01-01

    The effect of accurate positioning of TLD-100 samples in the center of the reader planchet on precision and kinetic parameters was investigated. Significant improvement in precision is obtained by careful positioning of the sample in the center of the planchet, by as much as 40%, 20% and 30% using different methods of glow curve analysis to estimate the intensity of the TL signal. - Highlights: • The effect of accurate positioning of TLD-100 samples on precision and kinetic parameters was investigated. • Significant improvement in precision was obtained. • Significant improvement in the calculation of the kinetic parameters of individual peaks was achieved. • The optimum protocol involves a depression matched to the size of the sample was developed

  2. Report Card on Basal Readers.

    Science.gov (United States)

    Goodman, Kenneth S.; And Others

    This report examines the nature of the modern basal reader, its economics, and use. First, the report provides a history showing how the confluence of business principles, positivistic science, and behavioral psychology led to the transformation of reading textbooks into basal readers. Next, the report examines objectives and subjective factors…

  3. The Routledge Applied Linguistics Reader

    Science.gov (United States)

    Wei, Li, Ed.

    2011-01-01

    "The Routledge Applied Linguistics Reader" is an essential collection of readings for students of Applied Linguistics. Divided into five sections: Language Teaching and Learning, Second Language Acquisition, Applied Linguistics, Identity and Power and Language Use in Professional Contexts, the "Reader" takes a broad…

  4. Brazilian two-component TLD albedo neutron individual monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Martins, M.M., E-mail: marcelo@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD), Av. Salvador Allende, s/n, CEP: 22780-160, Rio de Janeiro, RJ (Brazil); Mauricio, C.L.P., E-mail: claudia@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD), Av. Salvador Allende, s/n, CEP: 22780-160, Rio de Janeiro, RJ (Brazil); Fonseca, E.S. da, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD), Av. Salvador Allende, s/n, CEP: 22780-160, Rio de Janeiro, RJ (Brazil); Silva, A.X. da, E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao em Engenharia, COPPE/PEN Caixa Postal 68509, CEP: 21941-972, Rio de Janeiro, RJ (Brazil)

    2010-12-15

    Since 1983, Instituto de Radioprotecao e Dosimetria, Brazil, uses a TLD one-component albedo neutron monitor, which has a single different calibration factor specifically for each installation type. In order to improve its energy response, a two-component albedo monitor was developed, which measure the thermal neutron component besides the albedo one. The two-component monitor has been calibrated in reference neutron fields: thermal, five accelerator-produced monoenergetic beams (70, 144, 565, 1200 and 5000 keV) and five radionuclide sources ({sup 252}Cf, {sup 252}Cf(D{sub 2}O), {sup 241}Am-Be, {sup 241}Am-B and {sup 238}Pu-Be) at several distances. Since January 2008, mainly Brazilian workers who handle neutron sources at different distances and moderation, such as in well logging and calibration facilities are using it routinely.

  5. Automatic Imitation

    Science.gov (United States)

    Heyes, Cecilia

    2011-01-01

    "Automatic imitation" is a type of stimulus-response compatibility effect in which the topographical features of task-irrelevant action stimuli facilitate similar, and interfere with dissimilar, responses. This article reviews behavioral, neurophysiological, and neuroimaging research on automatic imitation, asking in what sense it is "automatic"…

  6. Analysis of uncertainties in the IAEA/WHO TLD postal dose audit system

    Energy Technology Data Exchange (ETDEWEB)

    Izewska, J. [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, Vienna (Austria)], E-mail: j.izewska@iaea.org; Hultqvist, M. [Department of Medical Radiation Physics, Karolinska Institute, Stockholm University, Stockholm (Sweden); Bera, P. [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, Vienna (Austria)

    2008-02-15

    The International Atomic Energy Agency (IAEA) and the World Health Organisation (WHO) operate the IAEA/WHO TLD postal dose audit programme. Thermoluminescence dosimeters (TLDs) are used as transfer devices in this programme. In the present work the uncertainties in the dose determination from TLD measurements have been evaluated. The analysis of uncertainties comprises uncertainties in the calibration coefficient of the TLD system and uncertainties in factors correcting for dose response non-linearity, fading of TL signal, energy response and influence of TLD holder. The individual uncertainties have been combined to estimate the total uncertainty in the dose evaluated from TLD measurements. The combined relative standard uncertainty in the dose determined from TLD measurements has been estimated to be 1.2% for irradiations with Co-60 {gamma}-rays and 1.6% for irradiations with high-energy X-rays. Results from irradiations by the Bureau international des poids et mesures (BIPM), Primary Standard Dosimetry Laboratories (PSDLs) and Secondary Standards Dosimetry Laboratories (SSDLs) compare favourably with the estimated uncertainties, whereas TLD results of radiotherapy centres show higher standard deviations than those derived theoretically.

  7. Traceability of a panoramic gamma irradiator using different TLD systems as transfer instruments

    International Nuclear Information System (INIS)

    Romero, A.M.; Saez, J.C.

    1994-01-01

    This work shows the calibration in terms of the new operational radiological quantities Hp(10) and H*(10) for different TLD systems (Harshaw TLD-100 and Panasonic UD-802) used in personal and environmental monitoring. The irradiations were performed in the Spanish Reference Laboratory in radiation protection levels, managed by the CIEMAT Metrology of ionizing radiations Unit. With these data, different calibrations of a panoramic gamma irradiator in terms of the radiological quantity for unit of time were established, providing the traceability of the irradiator to the Reference Laboratory using the corresponding TLD systems as transfer instruments. (Author) 9 refs

  8. Traceability of a panoramic gamma irradiator using different TLD systems as transfer Instruments

    International Nuclear Information System (INIS)

    Romero, A. M.; Saez, J. C

    1994-01-01

    This work shows the calibration in terms of the new operational radiological quantities Hp (10) and H(10) for different TLD systems (Harshaw TLD-100 and Panasonic UD-002) used in personal and environmental monitoring. The irradiations were performed in the Spanish Reference Laboratory in radiation protection levels, managed by the CIEMAT Metrology of ionizing radiations Unit. With those data, different calibrations of a panoramic gamma irradiator in terms of the radiological quantity for unit of time were established, providing the traceability of the irradiator to the Reference Laboratory using the corresponding TLD systems as transfer instruments. (Author) 9 refs

  9. Experimental determination of the photon-energy dependent dose-to-water response of TLD600 and TLD700 (LiF:Mg,Ti) thermoluminescence detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schwahofer, Andrea [Vivantes Clinic Neukoelln, Berlin (Germany). Dept. of Radiation Therapy; German Cancer Research Center, Heidelberg (Germany). Medical Physics in Radiation Therapy; Feist, Harald [Munich Univ. (Germany). Dept. of Radiation Therapy; Georg, Holger [PTW Freiburg (Germany). Calibration Lab.; Haering, Peter; Schlegel, Wolfgang [German Cancer Research Center, Heidelberg (Germany). Medical Physics in Radiation Therapy

    2017-05-01

    The aim of this study has been the experimental determination of the energy dependent dose-to-water response of TLD600 and TLD700 thermoluminescent detectors (Harshaw) in X-ray beams with mean photon energies from about 20 to 200 keV in comparison with {sup 60}Co gamma rays and 6 MV X-rays. Experiments were carried out in collaboration with the German secondary standard laboratory PTW Freiburg. The energy dependent relative responses of TLD600 and TLD700 thermoluminescence detectors were determined at radiation qualities between 30 kV{sub p} and 280 kV{sub p}. The overall uncertainty of the measured values was characterized by standard deviations varying from 1.2 to 3%. The present results agree with previous studies on the energy dependent dose-to-water response of TLD100. As an application example, the results were used to measure doses associated with X-ray imaging in image-guided radiotherapy.

  10. Vivo dosimetry using TLD detectors in prostate seed implants of I-125: preliminary results

    International Nuclear Information System (INIS)

    Sanchez-Reyes, A.; Pedro, A.; Bassas, P.; Duch, M. A.; Cros, M.; Mane, S.

    2011-01-01

    We present preliminary results of a new in vivo dosimetry technique that could allow to know immediately after implantation of the prostate if the dose distribution determined by the scheduler is similar to the actual dose measured with TLD detectors.

  11. NRC [Nuclear Regulatory Commission] TLD [thermoluminescent dosimeter] direct radiation monitoring network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1989-09-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the second quarter of 1989

  12. NRC TLD [thermoluminescent dosimeter] Direct Radiation Monitoring Network: Progress report, January-March 1988

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1988-06-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the first quarter of 1988

  13. Postal TLD audits in radiotherapy in the Czech Republic: current status, experience and potential

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Kapucianova, Michaela; Dufek, Vladimir

    2014-01-01

    The paper deals with practice and performance of postal TLD audits in radiotherapy with emphasis on the possibilities of application of the advanced versions that were developed following up technological progress in radiotherapy. The new methodologies of the TLD audit are focused specifically on up-to-date linear accelerators, equipped with multileaf collimators, and modern treatment planning systems. The dose is checked by the TLD not only for reference conditions but also in conditions of radiation fields influenced by presence of inhomogeneities in the irradiated volume. As regards small radiation fields, the check also includes dose profile verification using gafchromic films. The methodologies were tested within pilot studies performed in collaboration with some Czech radiotherapy centers. The results and experience gave evidence of the usefulness and appropriateness of the new TLD audit methodologies. (orig.)

  14. NRC TLD direct radiation monitoring network: Progress report, April--June 1988

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1988-09-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facility sites throughout the country for the second quarter of 1988

  15. Methods on TLD management be applicable in nuclear power plantsunder the multi-reactor operational mode

    International Nuclear Information System (INIS)

    Luo Huiyong; Wen Qinghua; Li Ruirong; Yu Enjian

    2006-01-01

    This paper discusses the methods on management of TLD dosimeters adopted in DNMC and other NPPs, analyzes and evaluates their both defects and advantages. Facing the coming of the multi-reactor operational mode applied in NPPs, a new method intelligent management mode is put forward, this optimized method not only assures the accuracy of TLD's measurement but also reduces the cost of production and improves the efficiency of management greatly. (authors)

  16. The application of artificial neural networks to TLD dose algorithm

    International Nuclear Information System (INIS)

    Moscovitch, M.

    1997-01-01

    We review the application of feed forward neural networks to multi element thermoluminescence dosimetry (TLD) dose algorithm development. A Neural Network is an information processing method inspired by the biological nervous system. A dose algorithm based on a neural network is a fundamentally different approach from conventional algorithms, as it has the capability to learn from its own experience. The neural network algorithm is shown the expected dose values (output) associated with a given response of a multi-element dosimeter (input) many times.The algorithm, being trained that way, eventually is able to produce its own unique solution to similar (but not exactly the same) dose calculation problems. For personnel dosimetry, the output consists of the desired dose components: deep dose, shallow dose, and eye dose. The input consists of the TL data obtained from the readout of a multi-element dosimeter. For this application, a neural network architecture was developed based on the concept of functional links network (FLN). The FLN concept allowed an increase in the dimensionality of the input space and construction of a neural network without any hidden layers. This simplifies the problem and results in a relatively simple and reliable dose calculation algorithm. Overall, the neural network dose algorithm approach has been shown to significantly improve the precision and accuracy of dose calculations. (authors)

  17. TLD DRD dose discrepancy: role of beta radiation fields

    International Nuclear Information System (INIS)

    Munish Kumar; Pradhan, S.M.; Bihari, R.R.; Bakshi, A.K.; Chougaonkar, M.P.; Babu, D.A.R.; Gupta, Anil

    2014-01-01

    Ionization chamber based direct reading/pocket dosimeters (DRDs), are used along with the legal dosimeters (thermoluminescent dosimeters-TLDs) for day to day monitoring and control of radiation doses received by radiation workers. The DRDs are routinely used along with the passive dosimeters (TLDs) in nuclear industry at different radiation installations where radiation levels could vary significantly and the possibility of receiving doses beyond investigation levels by radiation workers is not ruled out. Recently, recommendations for dealing with discrepancies between personal dosimeter systems used in parallel were issued by ISO. The present study was performed to measure the response of ionization chamber based pocket dosimeters to various beta sources having energy (E max ) ranging from 0.224 MeV-3.54 MeV. It is expected that the above study will be useful in resolving the disparity between TLD and DRD doses at those radiation installations where radiation workers are likely to be exposed simultaneously from photons and beta particles

  18. Use of MCNP to compare the response of dose deposited in the TLD 100, TLD 600 and TLD 700 in radiation fields due to {sup 60}Co and {sup 241}AmBe source; Uso do MCNP para comparacao das respostas de dose depositada nos TLD 100, TLD 600 e TLD 700 em campos de irradiacao devido a fontes de {sup 60}Co e {sup 241}AmBe

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, Tassio A.; Castro, Vinicius A.; Siqueira, Paulo T.D., E-mail: tassio.cavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-08-15

    The successes of Boron Neutron Capture Therapy (BNCT) depend on the ability to deliver an adequate irradiation field to the target cells. Neutron beams used in BNCT are mostly driven from reactors and therefore, not only have a neutron energy range which far exceeds the thermal region but also do have a great gamma component. Beam characterization and dosimetry are consequently one of the essential procedures to be overcome to properly apply this technique. One of the methods currently used in mixed field (field containing both neutron and gamma) characterization, lies on the use of a pair of detectors with distinct responses to each beam component. But this technique needs to be better understood of how each thermoluminescent dosimeter (TLD) behaves in a mixed field or in a pure field. This work presents the results of a set of simulations performed in order to analyze the response of three ordinary types of TLDs - TLD 100, TLD 600 and TLD 700 - submitted to different irradiation fields from a Cobalt source and an Americium-Beryllium source inside a paraffin disk. And is also a possible method for performing the selection and calibration of theses TLDs. (author)

  19. Assessment of dose using TLD during activity handling at RPhL, BRIT

    International Nuclear Information System (INIS)

    Choughule, Nitin V.; Bairwa, S.M.; Murali, S.; Rakesh, R.B.; Madhumita, B.; Adtani, M.M.; Mehra, Kiran; Padmanabhan, D.; Borkute, S.D.; Pal, N.; Sachdev, S.S.

    2012-01-01

    Radiopharmaceutical Lab (RPhL), BRIT undertakes production, supply of radiopharmaceuticals. At RPhL short lived isotopes 131 I, 99 Mo, 99m Tc, 125 I, 153 Sm, 32 P and 51 Cr, are handled with total activity handled per week ranging from MBq to TBq (mCiCi). Radiological survey provides idea on radiation level helps to ensure safe working condition. In order to improve the working condition and to estimate the integrated dose over a period of week with uniform pattern of activity handling in the period, a study was carried out using TLD badges. Specifically prepared TLD badges containing CaSO 4 :Dy phosphor were placed at various locations at RPhL It is used for personnel monitoring. One set of TLD was exposed for a week long period while the other set was exposed only during activity handling, kept in the lead pot during the rest of the period. Dose measured by TLDs were compared with the dose estimated using the survey data for the respective locations as well as with the dose estimated using the activity handled by taking into account the time, distance and shielding. The maximum radiation level recorded during lab survey was used to estimate the TLD exposure during the period. It was observed that results on TLD dose measurement and estimated doses using survey results were of same order. The cumulative TLD dose recorded for week duration (168 h) was significantly higher than doses recorded by exposed TLD only during activity handling (8 h). It was expected that the TLD dose would not be more than dose estimated using radiation survey data, while in 3 among 8 experimental TLDs, the dose was ∼ 25% higher. This could be due to the movement of active material or open handling of activity do not get reflected during normal radiation survey and contribution from background radiation at the lab where those TLDs were placed. The individual dose of all the personnel working in different labs were well within the relevant dose limits indicating the safe working condition

  20. Effects of annealing on the sensitivity of LiF TLD-100 after repeated use for low dose measurements

    International Nuclear Information System (INIS)

    Ogunleye, O.T.; Richmond, R.G.

    1987-01-01

    The changes in sensitivity of LiF TLD-100 extruded ribbons subjected to repeated use up to 100 times were investigated. Three different annealing regimes were compared. The dosemeters were annealed at 400 0 C followed by (i) a slow or (ii) fast cooling to room temperature or (iii) utilising a 20 s readout process in the reader without a high temperature annealing at 400 0 C. Each of the three groups consisted of two sets of 20 chips each, with one set receiving 500 μ Gy of 90 Sr beta radiation and the other unirradiated. Sensitivity evaluations were performed every five cycles through the first 50 cycles, and on each tenth cycle thereafter. On the average, the fast cooled group maintained their integrity best, while a maximum variation in sensitivity of about 15% was observed in the irradiated set of the slowly cooled group. A permanent increase in sensitivity of at least 10% was observed for the set of dosemeters receiving radiation without annealing. Glow curve analyses showed an increase in the ratio of peaks 4 and 5 with repeated use of this group. (author)

  1. Hand book on the use of TLD badge based on CaSO4:Dy teflon TLD discs for individual monitoring

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Adtani, M.M.; Varadharajan, G.; Bakshi, A.K.; Srivastava, Kshama; Bihari, R.R.

    2002-10-01

    Individual monitoring is one of the most important aspects of a radiation protection programme. In India, an official and centralized personnel monitoring service to radiation workers started in 1952. With the indigenous development of a TLD badge system in 1975 at Bhabha Atomic Research Centre, decentralization of monitoring service was initiated. At present, about 40,000 radiation workers are monitored using this system through twelve TLD units located in different parts of the country, including a private accredited laboratory. Regulatory and other inspecting bodies have often asked outstation TLD units to produce a duly approved document on the procedures being practiced for the assessment of personal doses. A need for such a document has also been felt to ensure the uniformity in processing of dosemeters, recording and reporting of doses by different TLD units and to provide guidelines regarding the infrastructure requirement. This document in the form of a handbook has been prepared to cater to the above needs. The handbook is expected to provide necessary guidelines not only to the newcomers/ forthcoming units and the existing laboratories but also to help the regulators, inspectors and assessors. (author)

  2. ALGORITHM VERIFICATION FOR A TLD PERSONAL DOSIMETRY SYSTEM

    International Nuclear Information System (INIS)

    SHAHEIN, A.; SOLIMAN, H.A.; MAGHRABY, A.

    2008-01-01

    Dose algorithms are used in thermoluminescence personnel dosimetry for the interpretation of the dosimeter response in terms of equivalent dose. In the present study, an automated Harshaw 6600 reader was vigorously tested prior to the use for dose calculation algorithm according to the standard established by the US Department of Energy Laboratory Accreditation Program (DOELAP). Also, manual Harshaw 4500 reader was used along with the ICRU slab phantom and the RANDO phantom in experimentally determining the photon personal doses in terms of deep dose; Hp(10), shallow dose; Hp(0.07), and eye lens dose; Hp(3). Also, a Monte Carlo simulation program (VMC-dc) free code was used to simulate RANDO phantom irradiation process. The accuracy of the automated system lies well within DOELAP tolerance limits in all test categories

  3. SU-E-I-09: Application of LiF:Mg,Cu (TLD-100H) Dosimeters for in Diagnostic Radiology

    International Nuclear Information System (INIS)

    Sina, S; Zeinali, B; Karimipourfard, M; Lotfalizadeh, F; Sadeghi, M; Faghihi, R

    2014-01-01

    Purpose: Accurate dosimetery is very essential in diagnostic radiology. The goal of this study is to verify the application of LiF:Mg,Cu,P (TLD100H) in obtaining the Entrance skin dose (ESD) of patients undergoing diagnostic radiology. The results of dosimetry performed by TLD-100H, were compared with those obtained by TLD100, which is a common dosimeter in diagnostic radiology. Methods: In this study the ESD values were measured using two types of Thermoluminescence dosimeters (TLD-100, and TLD-100H) for 16 patients undergoing diagnostic radiology (lumbar spine imaging). The ESD values were also obtained by putting the two types of TLDs at the surface of Rando phantom for different imaging techniques and different views (AP, and lateral). The TLD chips were annealed with a standard procedure, and the ECC values for each TLD was obtained by exposing the chips to equal amount of radiation. Each time three TLD chips were covered by thin dark plastic covers, and were put at the surface of the phantom or the patient. The average reading of the three chips was used for obtaining the dose. Results: The results show a close agreement between the dose measuered by the two dosimeters.According to the results of this study, the TLD-100H dosimeters have higher sensitivities (i.e.signal(nc)/dose) than TLD-100.The ESD values varied between 2.71 mGy and 26.29 mGy with the average of 11.89 mGy for TLD-100, and between 2.55 mGy and 27.41 mGy with the average of 12.32 mGy for measurements. Conclusion: The TLD-100H dosimeters are suggested as effective dosimeters for dosimetry in low dose fields because of their higher sensitivities

  4. SU-E-I-09: Application of LiF:Mg,Cu (TLD-100H) Dosimeters for in Diagnostic Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Sina, S [Radiation Research Center, Shiraz University, Shiraz (Iran, Islamic Republic of); Zeinali, B; Karimipourfard, M; Lotfalizadeh, F; Sadeghi, M [Nuclear Engineering Department, Shiraz University, Shiraz (Iran, Islamic Republic of); Faghihi, R [Radiation Research Center, Shiraz University, Shiraz (Iran, Islamic Republic of); Nuclear Engineering Department, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2014-06-01

    Purpose: Accurate dosimetery is very essential in diagnostic radiology. The goal of this study is to verify the application of LiF:Mg,Cu,P (TLD100H) in obtaining the Entrance skin dose (ESD) of patients undergoing diagnostic radiology. The results of dosimetry performed by TLD-100H, were compared with those obtained by TLD100, which is a common dosimeter in diagnostic radiology. Methods: In this study the ESD values were measured using two types of Thermoluminescence dosimeters (TLD-100, and TLD-100H) for 16 patients undergoing diagnostic radiology (lumbar spine imaging). The ESD values were also obtained by putting the two types of TLDs at the surface of Rando phantom for different imaging techniques and different views (AP, and lateral). The TLD chips were annealed with a standard procedure, and the ECC values for each TLD was obtained by exposing the chips to equal amount of radiation. Each time three TLD chips were covered by thin dark plastic covers, and were put at the surface of the phantom or the patient. The average reading of the three chips was used for obtaining the dose. Results: The results show a close agreement between the dose measuered by the two dosimeters.According to the results of this study, the TLD-100H dosimeters have higher sensitivities (i.e.signal(nc)/dose) than TLD-100.The ESD values varied between 2.71 mGy and 26.29 mGy with the average of 11.89 mGy for TLD-100, and between 2.55 mGy and 27.41 mGy with the average of 12.32 mGy for measurements. Conclusion: The TLD-100H dosimeters are suggested as effective dosimeters for dosimetry in low dose fields because of their higher sensitivities.

  5. Deviations outside the acceptance limits in the IAEA/WHO TLD audits for radiotherapy hospitals

    International Nuclear Information System (INIS)

    Vatnitsky, S.; Izewska, J.

    2002-01-01

    The main purpose of the IAEA/WHO TLD postal dose audit programme for dosimetry in radiotherapy is to provide an independent verification of the dose delivered by treatment machines in radiotherapy hospitals. The results of the TLD audit are considered acceptable if the relative deviation between the participant's stated dose and the TLD determined dose is within ±5%. The goal of this note is to draw the attention of participants of the TLD programme to some of the common reasons for deviations outside the acceptance limits. Armed with this knowledge, other participants may avoid similar problems in the future. The analysis of deviations presented here is based on the results of TLD audits of the calibration of approximately 1000 Co-60 beams and 600 high-energy X-ray beams performed in the period 1996-2001. A total of 259 deviations outside the ±5% limits have been detected, including 204 deviations for Co-60 beams (20% of all Co-60 beams checked) and 55 for high-energy X-ray beams (10% of all X-ray beams checked). It is worth mentioning that the percentage of large deviations (beyond 10%) is also higher for Co-60 beams than for high-energy X-ray beams. Some problems may be caused by obsolete dosimetry equipment or poor treatment machine conditions. Other problems may be due to insufficient training of staff working in radiotherapy. The clinical relevance of severe TLD deviations detected in the audit programme was confirmed in many cases, but, fortunately, not all-poor dosimetric results reflect deficiencies in the calibration of clinical beams or machine faults. Sometime it happens, that the TLDs are irradiated with an incorrect dose due to misunderstanding of the instructions on how to perform the TLD irradiation. Such dosimetry errors would have no direct impact on actual dose delivered to a patient

  6. Evaluation of TLD dose response compared to MCNP-5 simulation of diagnostic X ray equipment - radiation diagnostic image

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez G, R.; Cavalieri, T. A.; De Paiva, F.; Dalledone S, P. de T.; Yoriyaz, H. [Instituto de Pesquisas Energeticas e Nucleares, Centro de Engenharia Nuclear / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Rodrigues F, M. A. [Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Dermatologia e Radioterapia, Av. Prof. Montenegro s/n, Rubiao Junior, 18601-970 Botucatu (Brazil); Vivolo, V., E-mail: chancez@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares, Gerencia de Metrologia das Radiacoes / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    The thermo luminescent dosimeter (TLD) is used as a radiation dosimeter and can be used as environmental and staff personnel monitoring. The TLD measures ionizing radiation exposure by a process in which the amount of radiation collected by the dosimeter is converted in visible light when the crystal is heated. The amount of emitted light is proportional to the radiation exposure, and then the response of the TLD must be the related to the real dose. In this work it was used twenty four TLD 700 in order to obtain eight values of doses from a diagnostic X-ray equipment. The TLD-700 is a LiF TLD enriched with {sup 7}Li isotope. One way to compare and study the response of TLD is by Monte Carlo method, which has been used as a computational tool to solve problems stochastically. This method can be applied to any geometry, even those where the boundary conditions are unknown, making the method particularly useful to solve problems a priori. In this work it was modeled the X-ray tube exactly as the one used to irradiate the TLD, after the simulation and the TLD irradiation the results of dose value from both were compared. (Author)

  7. Evaluation of TLD dose response compared to MCNP-5 simulation of diagnostic X ray equipment - radiation diagnostic image

    International Nuclear Information System (INIS)

    Sanchez G, R.; Cavalieri, T. A.; De Paiva, F.; Dalledone S, P. de T.; Yoriyaz, H.; Rodrigues F, M. A.; Vivolo, V.

    2014-08-01

    The thermo luminescent dosimeter (TLD) is used as a radiation dosimeter and can be used as environmental and staff personnel monitoring. The TLD measures ionizing radiation exposure by a process in which the amount of radiation collected by the dosimeter is converted in visible light when the crystal is heated. The amount of emitted light is proportional to the radiation exposure, and then the response of the TLD must be the related to the real dose. In this work it was used twenty four TLD 700 in order to obtain eight values of doses from a diagnostic X-ray equipment. The TLD-700 is a LiF TLD enriched with 7 Li isotope. One way to compare and study the response of TLD is by Monte Carlo method, which has been used as a computational tool to solve problems stochastically. This method can be applied to any geometry, even those where the boundary conditions are unknown, making the method particularly useful to solve problems a priori. In this work it was modeled the X-ray tube exactly as the one used to irradiate the TLD, after the simulation and the TLD irradiation the results of dose value from both were compared. (Author)

  8. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries; Intercomparacion TLD en aceleradores para radioterapia en tres paises latinoamericanos

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L. [Depto. El Hombre y su Ambiente. Universidad Autonoma Metropolitana, Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)

    1998-12-31

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  9. A method to minimise the fading effects of LiF:Mg,Ti (TLD-600 and TLD-700) using a pre-heat technique.

    Science.gov (United States)

    Lee, YoungJu; Won, Yuho; Kang, Kidoo

    2015-04-01

    Passive integrating dosemeters [thermoluminescent dosimeter (TLD) and optically stimulated luminescence (OSL)] are the only legally permitted individual dosemeters for occupational external radiation exposure monitoring in Korea. Also its maximum issuing cycle does not exceed 3 months, and the Korean regulations require personal dosemeters for official assessment of external radiation exposure to be issued by an approved or rather an accredited dosimetry service according to ISO/IEC 17025. KHNP (Korea Hydro & Nuclear Power, LTD), a unique operating company of nuclear power plants (NPPs) in Korea, currently has a plan to extend a TLD issuing cycle from 1 to 3 months under the authors' fading error criteria, ±10%. The authors have performed a feasibility study that minimises post-irradiation fading effects within their maximum reading cycle employing pre-heating technique. They repeatedly performed irradiation/reading a bare TLD chip to determine optimum pre-heating conditions by analysing each glow curve. The optimum reading conditions within the maximum reading cycle of 3 months were decided: a pre-heating temperature of 165°C, a pre-heating time of 9 s, a heating rate of 25°C s(-1), a reading temperature of 300°C and an acquisition time of 10 s. The fading result of TLD-600 and TLD-700 carried by newly developed time temperature profile (TTP) showed a much smaller fading effect than that of current TTP. The result showed that the fading error due to a developed TTP resulted in a ∼5% signal loss, whereas a current TTP caused a ∼15% loss. The authors also carried out a legal performance test on newly developed TTP to confirm its possibility as an official dosemeter. The legal performance tests that applied the developed TTP satisfied the criteria for all the test categories. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. IAEA/ WHO TLD postal dose intercomparison results in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.; Bhuiyan, N.U.; Rahman, S.

    2001-01-01

    Full text: For the accurate delivery of prescribed dose to the patients, high precision and accuracy in radiation dosimetry is required. The hospital/medical physicist is responsible for the accurate delivery of whole planned radiation doses to the patients prescribed by the radio therapist. The proper delivery of radiation doses depends upon the accurate output measurements of doses from the therapy machines. In Bangladesh, only six 60 Co units and five deep therapy machines are in use. Some more are expected to be installed soon. Still in 2001, none of the Government radiotherapy centers in Bangladesh was properly equipped with medical physicists as well as radiotherapy dosimetry equipment. Bangladesh Atomic Energy Commission (BAEC) is responsible for radiation safety in Bangladesh and BAEC has assigned Secondary Standard Dosimetry Laboratory (SSDL) of Bangladesh for providing dosimetry calibration to all radiotherapy centers in Bangladesh. The output measurements of therapy machines are performed once in a year by SSDL and the results are compared by participating in the annual TLD postal dose intercomparison program organized by IAEA/WHO SSDL Network. The absorbed dose to water is determined using IAEA dosimetry protocol (TRS 277 and 381) and water phantom of size 30 x 30 x 30 cm 3 , The measurements of SSDL are traceable to NPL of UK. The accuracy achieved in SSDL, Bangladesh has been found better than ± 3.5%, which is within the prescribed limit of dosimetry standard of IAEA. The methodology of output dose measurements in different radiotherapy centers in Bangladesh is described along with the IAEA/WHO intercomparison results

  11. Performance test of a portable TLD system for accidental doses

    International Nuclear Information System (INIS)

    Mihelic, M.; Stuhec, M.; Mitic, D.; Vekic, B.; Miljanic, S.; Ban, R.

    2005-01-01

    Full text: A portable TLD measuring system was constructed at the J. Stefan Institute many years ago, motivated by the thread of a catastrophic nuclear event. It was designed for fast measurements in accidental dosimetry mainly for military and civil protection use. The system consists of a robust portable measuring unit built for measurements in field conditions, sized about 40 cm in diameter and weighting 5 kg. Dosimeters are based on CaF 2 :Mn ceramic tablets closed in water resistant plastic housings. In original design producer assured measuring range from cGy to kGy. Specially designed energy compensating filters are used to satisfy requirements for energy response from 0,1 to 3 MeV. Stability of readings is maintained with the temperature stabilized light source. Measuring time for manually driven heating-reading cycle of one dosimeter is about 30 sec. Many systems of the type with sets of dosimeters were stored unused for some years in depositories of different institutions. Modernization of equipment in last years raised questions of applicability of such measurement systems for contemporary needs. The system was thus tested in a secondary standards dosimetry laboratory for compliance with up to date requirements for accidental individual monitoring. Dosimeter characteristics as repeatability, linearity and directional response were of particular interest. As a result of the tests, technical improvements are suggested to extent systems measuring capabilities in order to meet new standards. Possibilities of its use in different fields of dosimetry are discussed, where quick in field measurements of high doses is required as for example in medicine or in civil protection motivated by the new threads of terrorist attacks. (author)

  12. Quality control in medical radiology using T.L.D

    International Nuclear Information System (INIS)

    Rolemberg Silva, F.A.; Nascimento Souza, D. do

    2006-01-01

    In this work tests of quality control in beams of X rays have been carried out, at diagnostic level, of two radiological services equipments of Brazilian hospitals (Aracaju, SE). We obtained the air kerma and kerma rate values, the beams efficiency, the coherence between the luminous fields and the referring fields of irradiation and half-value layer to each equipment and set of parameters. The measures of direct form have been obtained using two ionization chambers, one cylindrical and another one with parallel plates. An optional method for accomplishment some of the tests were carried out with CaSO 4 :Dy + Teflon thermoluminescent dosimeters. The values of air kerma were evaluated for three tube voltage, 40, 60 and 81 kV at 1.0 m from the focus of the equipments. For each one of the voltages three distinct current values were chosen besides a fixed value of exposition time. The results showed that the values of air kerma varied between 8.0 μGy and 0.35 μGy. The T.L.D. have revealed useful for the measures if the response to the dose is previously known for each set of beam parameters used for the irradiations. Otherwise, the tests with the dosimeters can serve to evaluate the beams conditions and their reproducibility. The evaluation results of coherence between the luminous fields and the irradiation fields demonstrated that the difference between the radiation and the luminous fields did not exceed 2% of the distance between the focal point and the film. We found satisfactory values for half-value layer. (author)

  13. Triage for Struggling Adolescent Readers

    Science.gov (United States)

    Diamond, Linda J.

    2006-01-01

    To improve achievement for struggling readers in particular, secondary schools must design programs and curricula to address students' lack of background knowledge, delayed English language development, and limited success in reading. In this article, the author presents a systems approach that offers intensive care for the most at-risk students…

  14. Readers' Knowledge of Popular Genre

    Science.gov (United States)

    Dixon, Peter; Bortolussi, Marisa

    2009-01-01

    This research examined readers' knowledge of popular genres. Participants wrote short essays on fantasy, science fiction, or romance. The similarities among the essays were measured using latent semantic analysis (LSA) and were then analyzed using multidimensional scaling and cluster analysis. The clusters and scales were interpreted by searching…

  15. Serving Boys through Readers' Advisory

    Science.gov (United States)

    Sullivan, Michael

    2010-01-01

    Based on more than twenty years' experience working to get boys interested in reading, the author now offers his first readers' advisory volume. With an emphasis on nonfiction and the boy-friendly categories of genre fiction, the work offers a wealth of material including: (1) Suggestions for how to booktalk one-on-one as well as in large groups;…

  16. Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading; Respuesta termoluminiscente de dosimetros TLD-100 sujetos a distintos protocolos de horneado, irradiacion y lectura

    Energy Technology Data Exchange (ETDEWEB)

    Estrada E, D

    2002-07-01

    The interest that motivated the realization of this work is the opposing discrepancy among the values of the efficiency thermoluminescent of heavy charged particles (PCP) regarding gamma radiation ({eta}{sub PCP}, {gamma}) reported in different works and gathered recently for Horowitz (Ho 01). The measures of relative thermoluminescent efficiency have importance in relation to the dosimetry associated to medical therapy with heavy charged particle. The measurement of {eta}{sub PCP}, {gamma} depends of multiple experimental factors. To understand this dependence it was quantified the effect of using different procedures experimental in the estimate of the relative thermoluminescent efficiency of dosemeters TLD-100 (LiF: Ti; Mg) for protons of 3 MeV regarding gamma rays of {sup 60}Co ({eta}{sub PCP}, {gamma}), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for ({eta}{sub PCP}, {gamma}) inside the interval [0.30, 0.58] for the peak 5 and [0.35, 0.76] for the total thermoluminescent signal (Tl). At the use different equipment, baked and lot are obtained maximum differences of 30%, 12% and 6% respectively in the values of ({eta}{sub PCP}, {gamma}) for the peak 5, and 25%, 28% and 7% for the total Tl signal. The changes more significant of 36% and 44% for peak 5 and total signal respectively are obtained when changing the presentation of the dosemeter. As a complementary investigation it was studied the distribution of the Tl signal of each peak in the deconvolution of the curve of brightness with regard to the total signal in exposed dosemeters to high fluence of protons (1x10{sup 10} p/cm{sup 2}) varying the experimental protocol. It was found that the distribution of the Tl signal has a difference of the order of 5% when changing the used reading team. It was observed that the contribution of the peak 5 regarding the total signal are preserved when changing baked and that it

  17. Personnel dose equivalent monitoring at SLAC using lithium-fluoride TLD's [thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Jenkins, T.M.; Busick, D.D.

    1987-03-01

    TLD's replaced film badges in the early 1970's for all dose equivalent monitoring, both neutron and photon, and for all locations at SLAC. The photon TLD's, composed of Li-7 loaded teflon discs, are calibrated using conventional gamma-ray sources; i.e., Co-60, Cs-137, etc. For these TLD's a nominal value of 1 nC/mrem is used, and is independent of source energy for 100 keV to 3 MeV. Since measured dose equivalents at SLAC are only a small fraction of the allowable levels, it was not deemed necessary to develop neutron dosimeters which would measure dose equivalent accurately for all possible neutron spectra. Today, wallet TLD's, composed of pairs of Li-7 and Li-6 discs, are used, with the Li-6 measuring only thermal neutrons; i.e., they aren't moderated in any way to make them sensitive to neutrons with energies greater than thermal. The assumption is made that there is a correlation between thermal neutron fluences and fast neutron fluences around the research area where almost all neutron doses (exclusive of sealed sources) are received. The calibration factor for these Li-6 TLD's is 1 nC/mrem of fast neutrons. The method of determining the validity of this calibration is the subject of this note. 4 refs., 9 figs., 1 tab

  18. Improvement of Accuracy in Environmental Dosimetry by TLD Cards Using Three-dimensional Calibration Method

    Directory of Open Access Journals (Sweden)

    HosseiniAliabadi S. J.

    2015-06-01

    Full Text Available Background: The angular dependency of response for TLD cards may cause deviation from its true value on the results of environmental dosimetry, since TLDs may be exposed to radiation at different angles of incidence from the surrounding area. Objective: A 3D setting of TLD cards has been calibrated isotropically in a standard radiation field to evaluate the improvement of the accuracy of measurement for environmental dosimetry. Method: Three personal TLD cards were rectangularly placed in a cylindrical holder, and calibrated using 1D and 3D calibration methods. Then, the dosimeter has been used simultaneously with a reference instrument in a real radiation field measuring the accumulated dose within a time interval. Result: The results show that the accuracy of measurement has been improved by 6.5% using 3D calibration factor in comparison with that of normal 1D calibration method. Conclusion: This system can be utilized in large scale environmental monitoring with a higher accuracy

  19. Investigation of LiF, Mg and Ti (TLD-100 Reproducibility

    Directory of Open Access Journals (Sweden)

    Sadeghi M.

    2015-12-01

    Full Text Available LiF, Mg and Ti cubical TLD chips (known as TLD-100 are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC were obtained 4 times by irradiating them to doses of 81 mGy (two times, 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%.

  20. Investigation of LiF, Mg and Ti (TLD-100) Reproducibility.

    Science.gov (United States)

    Sadeghi, M; Sina, S; Faghihi, R

    2015-12-01

    LiF, Mg and Ti cubical TLD chips (known as TLD-100) are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy) with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC) were obtained 4 times by irradiating them to doses of 81 mGy (two times), 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%.

  1. Optimization of the temperature profiles due to a nitrogen jet impinging on a TLD detector

    International Nuclear Information System (INIS)

    Cohen, I.; Bar-Kohany, T.; German, U.; Ziskind, G.

    2014-01-01

    A study was conducted to simulate the temperature profiles during readout in a typical, commercial thermo-luminescence dosimeter (TLD) chip and to optimize the readout conditions. The study makes use of a previously developed numerical model which calculates the crystal's temperature profile evolution inside a TLD crystal compound. The calculated profiles were implemented in the Randall-Wilkins equation to obtain the estimated glow curve. A number of jet temperature profiles were investigated in order to optimize the readout process. - Highlights: • The temperature profiles in a TLD chip compound were simulated. • Some non-routine heating profiles are proposed. • A better efficiency and shorter time can be obtained with these profiles. • The resulting glow curves were evaluated as well

  2. Personal neutron monitoring using TLD albedo combined with etched tracks detector

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, N.; Momose, T. [Japan Nuclear Cycle Development Institute, Ibarakiken (Japan)

    2002-07-01

    The albedo dosimetry has been carried out in personal neutron monitoring in the MOX fuel plant of JNC Tokai Works, however, it has shortcomings mainly due to the inherently poor energy response. This paper describes our efforts to overcome these difficulties in practical use of albedo dosemeters. The following four subjects are presented: (1) the neutron energy response functions of albedo TLD obtained from the mono-energetic neutron irradiation experiments and the Monte-Carlo calculations, (2) the location- dependent correction factors calculated from the response functions and neutron energy spectra measured in the workplaces, (3) the results of the international personal neutron dosimetry intercomparison program, and (4) the operational comparison program of TLD albedo and etched tracks detector worn by workers engaged in the fabrication process of the MOX fuel plant. Finally, the characteristics of the combination neutron dosemeter using TLD albedo and solid state etched track detector are summarized.

  3. Program of TLD audits for quality control in radiotherapy

    International Nuclear Information System (INIS)

    Alvarez, P.; Feld, D.; Gomez, C.; Kessler, C.; Montano, R.G.; Lindner, C.; Peretti, M.; Saravi, M.; Miguez, V.; Paidon, S.; Raslawski, E.

    1998-01-01

    Full text: It is known that a high precision in radiotherapy is essential to ensure a successful radiation treatment. To reach this goal it is necessary to detect and minimise many errors, which can be done through a periodic program of quality control, not only internal checks but also participating in external audits that attempt to control the absorbed dose delivered and detect any source of error, coming from the machine itself or from human mistakes. Under the frame of the International Quality Assurance Network for Dosimetry in Radiotherapy proposed by the International Atomic Energy Agency, a National External Audit Group (EAG) has been created in our country, composed by the Secondary Standard Dosimetry Laboratory (SSDL), 2 Medical Physics and 1 Medical Radiotherapist. The SSDL and one of the Medical Physics belong to the National Atomic Energy Agency, meanwhile the rest of the group belong to the National Pediatric Hospital P rof. J.P.Garrahan . This EAG performs external audits to Radiation Therapy Centres with a thermoluminescence system, which is checked periodically by the IAEA. The audits are performed to the 60 Co γ-ray and high energy X-ray beams that are being used for medical application in the whole country. The SSDL is the responsible of the thermoluminescence measurements; deviation of the absorbed dose determined by the TLD system from the one informed by the Responsible of the Center within the interval ± 5% are considered acceptable while deviations out of this interval require the intervention of the Medical Physic Group and the Radiotherapist in order to determine the cause of the discrepancies. In 1997, 4 audits performed in reference conditions were carried out 68 60 Co units participated in the audits, 61 of them with deviation within the acceptable interval in their first participation, meanwhile 1 got this deviation in repeated audits, after the follow up performed by the Medical Physic Group. Regarding high energy X-ray beams

  4. Studies on dosimetric tests applying source irradiation force of Cs-137 for using in chambers for calibration and TLD type dosimeters

    International Nuclear Information System (INIS)

    Ribeiro, Laila Lorena X.; Barbosa, Rugles Cesar; Correa, Rosangela S.

    2011-01-01

    The West Central region of Brazil does not have a basic infrastructure for research, development, training programs, and personnel dosimetry education. All of them applied to environmental, industrial and medical uses. Service deployment for irradiance of TLD, via 137 Cs irradiator J. L. SHEPHERD model 28-8A (444 activity GBq) in CRCN-CO, it is necessary to introduce procedures for calibration of the radiator and other procedures related to dosimetry and calibration. Such procedures should be repeated periodically, as necessary to introduce techniques that make the service of the CRCN-CO a template, and that meet all standards requirements for radioprotection and operation of dosimetry and calibration. The objective of this work was to evaluate the radiation field of Cs-137, and the automatic system which systematizes the calibration procedures attached to a system control target for the radiator/calibration of monitors, and portable dosimeters. (author)

  5. Audit on dose delivery by using TLD in Radiotherapy Centers in Malaysia

    International Nuclear Information System (INIS)

    Md Saion Salikin; Taiman Kadni; Husaini Salleh; Asmaliza Hashim; Hasrul Husham Hussain

    2004-01-01

    The External Audit Group (EAQ) is established and supported by IAEA. Its main objective is to audit the accuracy of dose delivery to patients in radiotherapy centres or hospitals in developing countries in IAEA member states. At MINT the operation of EAG is managed by Medical Physics Group and supported by Secondary Standard Dosimetry Laboratory (SSDL), MINT. The selected radiotherapy centers are supplied with TLD powder in capsule form, to be irradiated with the required radiation doses, by their physicists. The irradiated TLD is analysed at SSDL. The result of the audit for a few radiotherapy centres in Malaysia, is presented in brief in this paper. (Author)

  6. Automated TLD systems: what can we expect from the market today?

    International Nuclear Information System (INIS)

    Duftschmid, K.E.; Strachotinsky, Ch.

    1990-01-01

    The personnel monitoring service at the Austrian Research Centre Seibersdorf, which presently handles some 16,000 dosemeters per month, has been operating for more than ten years with three automated TLD systems, Harshaw model 2271. In order to renew the instrumentation an extensive evaluation and comparison of four commercially available automated systems designed to the present state-of-the-art has been carried out. The test procedures included dosimetric performance, reliability, handling speed and throughput, and additional information such as glow curve evaluation etc. The results should provide useful advice to monitoring services interested in the application of modern automated TLD systems currently on the market. (author)

  7. Studies on {sup 63}Ni based check-light sources for TL readers

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Venkataraman, G. [Bhabha Atomic Research Centre, Bombay (India). Radiation Protection Services Div.; Udhayakyumar, J. [Bhabha Atomic Research Centre, Bombay (India). Board of Radiation and Isotope Technology; Page, A.G. [Bhabha Atomic Research Centre, Bombay (India). Radiochemistry Div.

    1995-12-31

    The performance of indigenously produced, electrodeposited {sup 63}Ni sources having 10 mm x 10 mm active area and individually coupled to a plastic scintillator has been studied. TL phosphors such as CaF{sub 2}, CaF{sub 2}:Dy, CaF{sub 2}:Tm, CaF{sub 2}:Eu, TLD-100 and CaSO{sub 4}:Dy with {sup 63}Ni have been studied for their possible use as check-light sources for testing TL readers. Stability at ambient temperatures (298-323 K), build-up and decrease of light output with time have been examined. A preliminary study of the fluorescent species in the gamma irradiated plastic scintillator has been made. (author).

  8. Developmental Trajectories for Children With Dyslexia and Low IQ Poor Readers

    Science.gov (United States)

    2016-01-01

    Reading difficulties are found in children with both high and low IQ and it is now clear that both groups exhibit difficulties in phonological processing. Here, we apply the developmental trajectories approach, a new methodology developed for studying language and cognitive impairments in developmental disorders, to both poor reader groups. The trajectory methodology enables identification of atypical versus delayed development in datasets gathered using group matching designs. Regarding the cognitive predictors of reading, which here are phonological awareness, phonological short-term memory (PSTM) and rapid automatized naming (RAN), the method showed that trajectories for the two groups diverged markedly. Children with dyslexia showed atypical development in phonological awareness, while low IQ poor readers showed developmental delay. Low IQ poor readers showed atypical PSTM and RAN development, but children with dyslexia showed developmental delay. These divergent trajectories may have important ramifications for supporting each type of poor reader, although all poor readers showed weakness in all areas. Regarding auditory processing, the developmental trajectories were very similar for the two poor reader groups. However, children with dyslexia demonstrated developmental delay for auditory discrimination of Duration, while the low IQ children showed atypical development on this measure. The data show that, regardless of IQ, poor readers have developmental trajectories that differ from typically developing children. The trajectories approach enables differences in trajectory classification to be identified across poor reader group, as well as specifying the individual nature of these trajectories. PMID:27110928

  9. Automatic personnel contamination monitor

    International Nuclear Information System (INIS)

    Lattin, Kenneth R.

    1978-01-01

    United Nuclear Industries, Inc. (UNI) has developed an automatic personnel contamination monitor (APCM), which uniquely combines the design features of both portal and hand and shoe monitors. In addition, this prototype system also has a number of new features, including: micro computer control and readout, nineteen large area gas flow detectors, real-time background compensation, self-checking for system failures, and card reader identification and control. UNI's experience in operating the Hanford N Reactor, located in Richland, Washington, has shown the necessity of automatically monitoring plant personnel for contamination after they have passed through the procedurally controlled radiation zones. This final check ensures that each radiation zone worker has been properly checked before leaving company controlled boundaries. Investigation of the commercially available portal and hand and shoe monitors indicated that they did not have the sensitivity or sophistication required for UNI's application, therefore, a development program was initiated, resulting in the subject monitor. Field testing shows good sensitivity to personnel contamination with the majority of alarms showing contaminants on clothing, face and head areas. In general, the APCM has sensitivity comparable to portal survey instrumentation. The inherit stand-in, walk-on feature of the APCM not only makes it easy to use, but makes it difficult to bypass. (author)

  10. Recognizing Young Readers' Spoken Questions

    Science.gov (United States)

    Chen, Wei; Mostow, Jack; Aist, Gregory

    2013-01-01

    Free-form spoken input would be the easiest and most natural way for young children to communicate to an intelligent tutoring system. However, achieving such a capability poses a challenge both to instruction design and to automatic speech recognition. To address the difficulties of accepting such input, we adopt the framework of predictable…

  11. Extending the E-Z Reader Model of Eye Movement Control to Chinese Readers

    Science.gov (United States)

    Rayner, Keith; Li, Xingshan; Pollatsek, Alexander

    2007-01-01

    Chinese readers' eye movements were simulated in the context of the E-Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the…

  12. Skin dose measurements using MOSFET and TLD for head and neck patients treated with tomotherapy

    International Nuclear Information System (INIS)

    Kinhikar, Rajesh A.; Murthy, Vedang; Goel, Vineeta; Tambe, Chandrashekar M.; Dhote, Dipak S.; Deshpande, Deepak D.

    2009-01-01

    The purpose of this work was to estimate skin dose for the patients treated with tomotherapy using metal oxide semiconductor field-effect transistors (MOSFETs) and thermoluminescent dosimeters (TLDs). In vivo measurements were performed for two head and neck patients treated with tomotherapy and compared to TLD measurements. The measurements were subsequently carried out for five days to estimate the inter-fraction deviations in MOSFET measurements. The variation between skin dose measured with MOSFET and TLD for first patient was 2.2%. Similarly, the variation of 2.3% was observed between skin dose measured with MOSFET and TLD for second patient. The tomotherapy treatment planning system overestimated the skin dose as much as by 10-12% when compared to both MOSFET and TLD. However, the MOSFET measured patient skin doses also had good reproducibility, with inter-fraction deviations ranging from 1% to 1.4%. MOSFETs may be used as a viable dosimeter for measuring skin dose in areas where the treatment planning system may not be accurate.

  13. Calibration of TLD cards to beta ray spectra of 32P

    International Nuclear Information System (INIS)

    Ben-Shachar, B.; German, U.; Naim, E.

    1994-01-01

    The results of the evaluation of TLD chips are received in nC, and we need to transform these values to mGy, in order to obtain the penetrating and the non-penetrating dose. The calibration factors were determined experimentally by irradiation the TLD chips with an uranium source. Beta rays having other spectra can cause incorrect values when estimating the non-penetrating dose. If the spectrum of the beta source is known, a specific evaluation of the calibration factor can be performed. In this report, the estimation of the calibration factor for a 32 P source is presented. LiF:Ti,Mg TLD cards were irradiated calibrated source of 90 Sr/ 90 Y and 204 Tl and non-calibrated source of 32 P, in order to find the beta correction factor for the spectrum of 32 P. Calculations of the beta correction factor were performed too, by applying the Loevinger equations to the geometry of the TLD chips used in our routine measurements. The calculated values of the beta correction factors are lower than the experimental ones. When comparing the ratios, between the beta factors of 32 P and 90 Sr/ 90 Y received from the experiments and from the calculation, we found them to be constant up to ±5%. (authors) 15 refs, 2 figs, 6 tabs

  14. Development and extension of TLD audit in radiation therapy in the Czech Republic

    International Nuclear Information System (INIS)

    Valenta, J.; Ekendahl, D.

    2005-01-01

    A comprehensive and adequate quality assurance (QA) program is a crucial factor in minimizing gross errors and in reducing uncertainties caused during any of consecutive steps of radiation therapy process. Since 1997, the measuring centre of National Radiation Protection Institute in Prague (NRPI) has been performing TLD audit in external beam radiation therapy via mailed TL dosimeters, as a part of comprehensive QA program. The objective of TLD audit is to check dose delivery accuracy at radiation therapy centers and to inform the State Office for Nuclear Safety (SONS) on the situation. The flexibility of the method enables NRPI to inspect each centre at least once every two years. Compared with the EU average, situation in the Czech Republic seems to be similar. 95 % of measurements show deviation up to 5 % (97 % in the EQUAL network). Nevertheless, the acceptance level is stricter (3 %) in the Czech Republic. This is affordable because o(the small size of the country, and better ability to confirm the results promptly , if tolerance levels are exceeded. Still, 84 % of results meet the criteria of 3 %. Both basic and advanced modes of TLD audit may discover deviations in clinical dosimetry or in treatment planning for reference and non reference .conditions, although they do not provide enough data for proper interpretation of errors. The results show the importance of independent TLD audit as a flexible and operational part of the comprehensive quality assurance program. (authors)

  15. Operating experience of an automated TLD dispensing system at CORAL facility

    International Nuclear Information System (INIS)

    Ajoy, K.C.; Dhanasekaran, A.; Arun, R.; Yuvaraj, N.; Karthikeyan, D.; Dheeraj, R.; Akila, R.; Santhanam, R.; Rajagopal, V.; Kumar, Amudhu Ramesh

    2016-01-01

    Monitoring of exposures to occupational workers on individual basis is a regulatory requirement to demonstrate compliance that the dose to the workers is well within the dose limit. Over three decades for monitoring of external exposures, CaSO 4 based Thermo luminescence dosimeters (TLDs), which exhibit the required accuracy, reliability and ruggedness have been employed. TLD cards with unique identification number are loaded in plastic cassettes along with photographs are placed in wooden racks at the entry of the controlled area of the plant. However, there is always a chance that a TLD may be misplaced, used by others or there could be a deliberate act of misuse or abuse. To circumvent this it was decided to install an automated TLD dispensing system with individual TLD tracking as well as locking arrangement. CORAL reprocessing facility at IGCAR was the first to install one such system at Kalpakkam and the operating experience of the system for the last two years is brought out in this paper

  16. Skin dose measurements using MOSFET and TLD for head and neck patients treated with tomotherapy.

    Science.gov (United States)

    Kinhikar, Rajesh A; Murthy, Vedang; Goel, Vineeta; Tambe, Chandrashekar M; Dhote, Dipak S; Deshpande, Deepak D

    2009-09-01

    The purpose of this work was to estimate skin dose for the patients treated with tomotherapy using metal oxide semiconductor field-effect transistors (MOSFETs) and thermoluminescent dosimeters (TLDs). In vivo measurements were performed for two head and neck patients treated with tomotherapy and compared to TLD measurements. The measurements were subsequently carried out for five days to estimate the inter-fraction deviations in MOSFET measurements. The variation between skin dose measured with MOSFET and TLD for first patient was 2.2%. Similarly, the variation of 2.3% was observed between skin dose measured with MOSFET and TLD for second patient. The tomotherapy treatment planning system overestimated the skin dose as much as by 10-12% when compared to both MOSFET and TLD. However, the MOSFET measured patient skin doses also had good reproducibility, with inter-fraction deviations ranging from 1% to 1.4%. MOSFETs may be used as a viable dosimeter for measuring skin dose in areas where the treatment planning system may not be accurate.

  17. Environmental dosimetry system based on LiF : Mg, Ti (TLD-100)

    International Nuclear Information System (INIS)

    Saez Vergara, J.C.

    1990-01-01

    The report presents the various tests carried out to the characterize a thermoluminescence environmental dosimetry systems, using the phosphor LiF:mg,Ti (TLD-100) in chip form. The holder has been specifically designed in order to obtain simplicity in the operation and to assure correct measurements in terms of the new operational quantities in radiation protection (ICRU-1985). Some topics in TLD Environmental Monitoring are discussed (Dark Current, Reference Light, Zero Reading, Free-in-Air or Phantom Calibration, Fading Correction, Transit Dose, etc.), and the proposed solutions are exposed. The tests performed have been designed to conform with the different existing international Standards and Recommendations (ANSI : N545-1975; IEC: Draft 45B-1987, ISO : DP 8034-19849. The data from an European Interlaboratory Programm (EUR-8932) have been used to evaluate the performance : the TLD System presented is among the best systems using TLD-100. The results obtained in the characterization (linearity, repeatability, detection threshold, residue, angular response, stability of stored information, etc.) show the optimum performance of this dosimetric system in its application to environmental gamma dose monitoring. Based on these results, two operational procedures have been developed for the application of this Dosimetric System, specially in Quality Assurance Monitoring Programs around Nuclear Plants in Spain. (author)

  18. NRPB TLD and dose record keeping service - further progress

    International Nuclear Information System (INIS)

    Greenslade, E.

    1979-01-01

    Various aspects of the National Radiological Protection Board's service are described. An increasing number of UK employers are transferring from film monitors, and record keeping is now provided for both large and small groups of workers. Data entry directly from punched cards prepared by the larger employers has reduced initial costs and therefore carries a reduced registration fee for these users. Computerized dose record keeping allows automatic retrieval of cumulative dose information from any NRPB record of previous employment, thus safeguarding itinerant workers. Warning Dose Reports are issued automatically when cumulative dose totals reach or exceed 60% of a limit, or when a dose rate greater than 0.1 rem per 4 weeks is recorded. Flexibility in wearing period results in dosemeter economy and reduces laboratory work load. High recorded doses can be checked by UV stimulation of both disks to confirm the accuracy of the previous measurement. Employers are provided with a comprehensive and accurate monitoring package, fulfilling HSE requirements and exempting employers from their former responsibility to keep their own comprehensive records. (UK)

  19. Characterization of {sup 6}LiF:Mg,Cu,P (TLD-600 H) estimate of E, b and s parameters

    Energy Technology Data Exchange (ETDEWEB)

    Andres, P. A., E-mail: andresp@cab.cnea.gov.ar [Centro Atomico Bariloche, Division Proteccion Radiologica / CNEA, Av. E. Bustillo Km 9.5, R8402AGP San Carlos de Bariloche (Argentina)

    2015-10-15

    LiF:Mg,Cu,P dosemeters are useful for low-dose measurements because of its high sensitivity compared to the LiF:Mg,Ti dosemeters. {sup 7}LiF:Mg,Cu,P have been used for environmental dosimetry in Bariloche Atomic Centre for almost a decade. Since {sup 6}LiF:Mg,Cu,P dosemeters were intended to be used for X ray diagnosis dosimetry in neonatology, they had to be characterized first. The main goal of measuring and analyzing Tl glow curves is the extraction of some parameters that can be used to describe the Tl process in the material. This job focused on the estimation of the activation energy E for the Tl traps, the frequency factor s and the order of kinetics b of the Tl process. Furthermore, the most appropriate time-temperature profile (Ttp) was determined as well as the annealing temperature and time, which resulted being 240 degrees C for 10 minutes. The Ttp used was 140 degrees C for 10 seconds, a heating rate of 20/s until 240 degrees C, remaining at this temperature for 20 seconds, and then an exponential cooling until 50 degrees C. After applying the whole glow-peak method for different orders of kinetic, and the Kitis equation assuming a first order kinetics, the values obtained were: E = (1.066 ± 0.025) eV, as a weighted average of both methods, and a frequency factor s = (3.57 ± 1.56) E-10 s{sup -1} again as a weighted average of both methods. In both cases a first order kinetics (b = 1) was assumed. The dosemeters were irradiated with a calibrated {sup 137}Cs source and read with a Harshaw TLD{sup TM} Model 3500 reader resulting in a minimum detectable dose of about 20 μGy. (Author)

  20. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    Energy Technology Data Exchange (ETDEWEB)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E{sub efective} = 33 keV), N-80 (E{sub efective} = 65 keV) and N-100 (E{sub efective} = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  1. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    International Nuclear Information System (INIS)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A.; Vega C, H. R.

    2016-10-01

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E_e_f_e_c_t_i_v_e = 33 keV), N-80 (E_e_f_e_c_t_i_v_e = 65 keV) and N-100 (E_e_f_e_c_t_i_v_e = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  2. Programmable automatic alpha--beta air sample counter

    International Nuclear Information System (INIS)

    Howell, W.P.

    1978-01-01

    A programmable automatic alpha-beta air sample counter was developed for routine sample counting by operational health physics personnel. The system is composed of an automatic sample changer utilizing a large silicon diode detector, an electronic counting system with energy analysis capability, an automatic data acquisition controller, an interface module, and a teletypewriter with paper tape punch and paper tape reader. The system is operated through the teletypewriter keyboard and the paper tape reader, which are used to instruct the automatic data acquisition controller. Paper tape programs are provided for background counting, Chi 2 test, and sample counting. Output data are printed by the teletypewriter on standard continuous roll or multifold paper. Data are automatically corrected for background and counter efficiency

  3. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries

    International Nuclear Information System (INIS)

    Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L.

    1998-01-01

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  4. Every reader his book – every book its reader?

    DEFF Research Database (Denmark)

    Kann-Christensen, Nanna; Balling, Gitte

    2014-01-01

    ’ advisory and audience development. This is achieved through an analysis of opinions and reflections expressed by 13 managers and librarians in all six county libraries in Denmark. The interviews are analysed through the model which merges three concepts: cultural policy, new public management......Collections are no longer the main attraction in libraries, and libraries are working to find new paths to tread. One strategy is to focus on reading and literature in new and surprising ways. The aim of this article is to enrich an understanding of activities situated in the span between readers...... and professional logics. Our findings show that Danish librarians’ views on readers’ advisory and audience development strike a balance between the experience and empowerment rationales with a prevailing focus on users. A user orientation and focus on user experiences have created a situation wherein the notions...

  5. Comparative study on skin dose measurement using MOSFET and TLD for pediatric patients with acute lymphatic leukemia.

    Science.gov (United States)

    Al-Mohammed, Huda I; Mahyoub, Fareed H; Moftah, Belal A

    2010-07-01

    The object of this study was to compare the difference of skin dose measured in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using metal oxide semiconductor field-effect transistors (mobile MOSFET dose verification system (TN-RD-70-W) and thermoluminescent dosimeters (TLD-100 chips, Harshaw/ Bicron, OH, USA). Because TLD has been the most-commonly used technique in the skin dose measurement of TBI, the aim of the present study is to prove the benefit of using the mobile MOSFET (metal oxide semiconductor field effect transistor) dosimeter, for entrance dose measurements during the total body irradiation (TBI) over thermoluminescent dosimeters (TLD). The measurements involved 10 pediatric patients ages between 3 and 14 years. Thermoluminescent dosimeters and MOSFET dosimetry were performed at 9 different anatomic sites on each patient. The present results show there is a variation between skin dose measured with MOSFET and TLD in all patients, and for every anatomic site selected, there is no significant difference in the dose delivered using MOSFET as compared to the prescribed dose. However, there is a significant difference for every anatomic site using TLD compared with either the prescribed dose or MOSFET. The results indicate that the dosimeter measurements using the MOSFET gave precise measurements of prescribed dose. However, TLD measurement showed significant increased skin dose of cGy as compared to either prescribed dose or MOSFET group. MOSFET dosimeters provide superior dose accuracy for skin dose measurement in TBI as compared with TLD.

  6. Comparison of neutron dose measured by Albedo TLD and etched tracks detector at PNC plutonium fuel facilities

    International Nuclear Information System (INIS)

    Tsujimura, N.; Momose, T.; Shinohara, K.; Ishiguro, H.

    1996-01-01

    Power Reactor and Nuclear Fuel Development Corporation (PNC) has fabricated Plutonium and Uranium Mixed OXide (MOX) fuel for FBR MONJU at Tokai works. In this site, PNC/Panasonic albedo TLDs/1/ are used for personnel neutron monitoring. And a part of workers wore Etched Tracks Detector (ETD) combined with TLD in order to check the accuracy of the neutron dose estimated by albedo TLD. In this paper, the neutron dose measured by TLD and ETD in the routine monitoring is compared at PNC plutonium fuel facilities. (author)

  7. A Sign Language Screen Reader for Deaf

    Science.gov (United States)

    El Ghoul, Oussama; Jemni, Mohamed

    Screen reader technology has appeared first to allow blind and people with reading difficulties to use computer and to access to the digital information. Until now, this technology is exploited mainly to help blind community. During our work with deaf people, we noticed that a screen reader can facilitate the manipulation of computers and the reading of textual information. In this paper, we propose a novel screen reader dedicated to deaf. The output of the reader is a visual translation of the text to sign language. The screen reader is composed by two essential modules: the first one is designed to capture the activities of users (mouse and keyboard events). For this purpose, we adopted Microsoft MSAA application programming interfaces. The second module, which is in classical screen readers a text to speech engine (TTS), is replaced by a novel text to sign (TTSign) engine. This module converts text into sign language animation based on avatar technology.

  8. Vivo dosimetry using TLD detectors in prostate seed implants of I-125: preliminary results; Dosimetria in vivo mediante detectores de TLD en implantes de prostata con semillas de I-125: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Reyes, A.; Pedro, A.; Bassas, P.; Duch, M. A.; Cros, M.; Mane, S.

    2011-07-01

    We present preliminary results of a new in vivo dosimetry technique that could allow to know immediately after implantation of the prostate if the dose distribution determined by the scheduler is similar to the actual dose measured with TLD detectors.

  9. Thermoluminescent relative efficiencies of TLD-100 for nitrogen ions respect of gamma radiation; Eficiencias termoluminiscentes relativas de TLD-100 para iones de nitrogeno respecto de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Concha S, K. [UNAM, Facultad de Ciencias, 04510 Mexico D.F. (Mexico); Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Gamboa de Buen, I. [ICN-UNAM, 04510 Mexico D.F. (Mexico); Rodriguez V, M.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E. [IFUNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    The purpose of this work is to measure the thermoluminescent relative efficiency of those TLD-100 dosemeters irradiated with nitrogen ions with respect to the gamma radiation of {sup 60} Co, in function of the linear energy transfer (LET). Two energy of such nitrogen ions were selected that has the same value from LET when impacting in the dosemeters but with E{sub 1} energy (4.8 MeV) and E{sub 2} (9.95 MeV) smaller and greater respectively that the energy of the Bragg peak. (Author)

  10. Featured Article: Genotation: Actionable knowledge for the scientific reader.

    Science.gov (United States)

    Nagahawatte, Panduka; Willis, Ethan; Sakauye, Mark; Jose, Rony; Chen, Hao; Davis, Robert L

    2016-06-01

    We present an article viewer application that allows a scientific reader to easily discover and share knowledge by linking genomics-related concepts to knowledge of disparate biomedical databases. High-throughput data streams generated by technical advancements have contributed to scientific knowledge discovery at an unprecedented rate. Biomedical Informaticists have created a diverse set of databases to store and retrieve the discovered knowledge. The diversity and abundance of such resources present biomedical researchers a challenge with knowledge discovery. These challenges highlight a need for a better informatics solution. We use a text mining algorithm, Genomine, to identify gene symbols from the text of a journal article. The identified symbols are supplemented with information from the GenoDB knowledgebase. Self-updating GenoDB contains information from NCBI Gene, Clinvar, Medgen, dbSNP, KEGG, PharmGKB, Uniprot, and Hugo Gene databases. The journal viewer is a web application accessible via a web browser. The features described herein are accessible on www.genotation.org The Genomine algorithm identifies gene symbols with an accuracy shown by .65 F-Score. GenoDB currently contains information regarding 59,905 gene symbols, 5633 drug-gene relationships, 5981 gene-disease relationships, and 713 pathways. This application provides scientific readers with actionable knowledge related to concepts of a manuscript. The reader will be able to save and share supplements to be visualized in a graphical manner. This provides convenient access to details of complex biological phenomena, enabling biomedical researchers to generate novel hypothesis to further our knowledge in human health. This manuscript presents a novel application that integrates genomic, proteomic, and pharmacogenomic information to supplement content of a biomedical manuscript and enable readers to automatically discover actionable knowledge. © 2016 by the Society for Experimental Biology and

  11. E-book Reader Devices and Libraries

    Directory of Open Access Journals (Sweden)

    Pažur, I.

    2011-03-01

    Full Text Available Most library studies thematically related to electronic books don't consider readers of electronic books. Only in recent years librarians conduct studies in which they want to find out readers' opinions about the possibilities, advantages and disadvantages of reading using e-readers, as well as their possible application in the libraries.User studies of e-readers have shown that their opinion is generally positive, but great attachment to traditional books is still present, e-readers are still seen only as an additional tool for reading. Sony with its e-reader (the latest Reader model Daily and Reader Store online bookstore (http://ebookstore.sony.com/is the only one who cooperate with libraries and has made lending electronic books possible. Cooperation was launched in 2009th,and the New York Public Library was the first library that offered such a service.Cooperation between Sony and libraries, indicates clearly what the near future could be if other online booksellers / publishers begin to follow the model of lending e-books through the libraries over the network. However it is possible that a large online bookstores / publishers consider that the further price reduction of e-readers and electronic books will constantly increase their sales, and in that case lending e-books will be unnecessary.Are the libraries ready for this scenario?

  12. Parallel analysis of film and TLD application in personal dosimetry of medical staff during application of invasive radiological procedures

    International Nuclear Information System (INIS)

    Misovic, M.; Boskovic, Z.; Spasic-Jokic, V.

    1997-01-01

    Although both types of dosimeters showed similar results for mentioned category of health care workers we wished to emphasize some advantages in use of TLD and film dosemeters in personal dosimetry. The main advantageous of film for dosimetric purposes are that it can provide visual representation of the radiation field and they are cheap, but there are lot of disadvantages. Advantages of TLD are based on: possibility for re-use, practically for whole users working life, small dimensions suitable for results, high precision and specially wide dose range. They are sensitive on low dose, practically for ten times more than film is. Disadvantages of TLD are based on their previous thermal and radiation history and on the fact that information about dose disappears after reading procedure. Considering advantages and disadvantages of both types of dosemeters we decided to propose TLD for routine hospital practice in personal dosimetry. (author)

  13. Reader-Centered Technical Writing

    Science.gov (United States)

    Narayanan, M.

    2012-12-01

    Technical writing is an essential part of professional communication and in recent years it has shifted from a genre-based approach. Formerly, technical writing primarily focused on generating templates of documents and sometimes it was creating or reproducing traditional forms with minor modifications and updates. Now, technical writing looks at the situations surrounding the need to write. This involves deep thinking about the goals and objectives of the project on hand. Furthermore, one observes that it is very important for any participatory process to have the full support of management. This support needs to be well understood and believed by employees. Professional writing may be very persuasive in some cases. When presented in the appropriate context, technical writing can persuade a company to improve work conditions ensuring employee safety and timely production. However, one must recognize that lot of professional writing still continues to make use of reports and instruction manuals. Normally, technical and professional writing addresses four aspects. Objective: The need for generating a given professionally written technical document and the goals the document is expected to achieve and accomplish. Clientele: The clientele who will utilize the technical document. This may include the people in the organization. This may also include "unintended readers." Customers: The population that may be affected by the content of the technical document generated. This includes the stakeholders who will be influenced. Environment: The background in which the document is created. Also, the nature of the situation that warranted the generation of the document. Swiss Psychologist Jean Piaget's view of Learning focuses on three aspects. The author likes to extend Jean Piaget's ideas to students, who are asked to prepare and submit Reader-Centered Technical Writing reports and exercises. Assimilation: Writers may benefit specifically, by assimilating a new object into

  14. Effects of phosphor proportion and grain size on photon energy response of CaSO4:Dy teflon TLD discs

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Bhatt, R.C.

    1979-01-01

    Effects of phosphor proportion and grain size on the photon energy dependence of CaSO 4 :Dy embedded teflon TLD discs have been studied. It was found that in the commonly used TLD disc compositions, the proportion of phosphor has only little effect on energy dependence. This dependence could be significantly reduced by using phosphor of grain size less than 1 μm. The experimental results are compared with calculated results. (Auth.)

  15. Impact of ANSI 2009 criteria for performance testing in TLD personnel monitoring

    International Nuclear Information System (INIS)

    MeenaI, P.; Rakesh, R.B.; Srivastava, Kshama; KoIambe, D.H.; Sapra, B.K.

    2014-01-01

    External Quality Assurance in TLD Personnel Monitoring Service was initiated in 1985, for periodic performance evaluation of various TLD Laboratories through postal exercise. Presently, all the 16 laboratories involved in Personnel Monitoring Service are covered under QA exercise. Since beginning, American National Standards Institute (ANSI) criteria have been adopted for performance testing in QA exercise. Presently, ANSI 2001 performance criteria along with ISO trumpet curve analysis method are being used for performance evaluation. In 2009, ANSI modified the performance evaluation criteria and this study evaluates its impact and feasibility of implementation of ANSI 2009 criteria in the quality assurance program for personnel monitoring. The performance of some laboratories evaluated using both ANSI 2001 and ANSI 2009 criteria have been discussed. The study shows that the ANSI 2009 criteria is more stringent and encourages even distribution of bias and standard deviation. This can be implemented with suitable modifications for performance evaluation

  16. Fast neutron responses of CaF2:Tm Teflon TLD discs of different thicknesses

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Hoffmann, W.

    1986-01-01

    The fact that in CaF 2 :Tm (TLD-300) the ratio of the heights of thermoluminescence (TL) glow peaks at 240 0 C and 150 0 C is greater for irradiations by high LET radiations than by gamma rays has been found useful for the simultaneous and separate measurement of fast neutron and gamma ray absorbed doses. A recent study has indicated that the mixed field dosimetric characteristics of CaF 2 :Tm could be significantly improved by using thin TLDs. In the present study, CaF 2 :Tm Teflon TLD discs of thickness as low as 0.05 mm were evaluated. The thin discs could be read out by using normal planchette heating if a 400 0 C heat treatment is given to the discs prior to irradiation and TL readout. Influence of encapsulation of thin dosemeters was studied and their utility in situations such as interface dosimetry is discussed. (author)

  17. Pattern check of TLD disc readings - an important tool to identify abnormal conditions in workplace

    International Nuclear Information System (INIS)

    Pradhan, S.M.; Sneha, C.; Bhattacharya, M.; Sahai, M.K.; Pradeep, Ratna; Datta, D.; Bhatnagar, Amit

    2016-01-01

    Personnel monitoring for external radiation using CaSO 4 :Dy based TLD badge is well established in Indian radiation protection program. TLD badge enables evaluation of occupational dose based on the pattern and values of the three disc readings. Different patterns of disc readings are obtained depending on the type and energy of radiation in the workplace. Pattern not conforming to the radiation in the workplace also called as improper pattern can be a useful tool for investigation of any deviation / abnormality in workplace or monitoring practices. The paper presents different examples of improper pattern observed in monitoring that has helped to find out the deviations in the workplace or monitoring practices. Results of the experiments conducted to simulate some of the observed pattern are also presented in the paper

  18. The Dependence of the Dose Response Supralinearity of Peak 5 in TLD-100 on Recombination Temperature

    International Nuclear Information System (INIS)

    Horowitz, Y.S.; Satinger, D.; Oster, L.

    1999-01-01

    Isothermal readout of LiF:Mg,Ti (TLD-700) has recently been used to study the dependence of the supralinearity of peak 5 on recombination temperature. The results were interpreted to be in conflict with earlier results which investigated the effect of readout heating rate on the supralinearity of peak 5 in TLD-100. In this work the two experiments are inspected in greater detail. It is illustrated that the isothermal decay data is not in conflict with the heating rate data. However, the heating rate results do apparently indicate a strong transition in the temperature dependence of the relative strengths of the recombination and competitive cross sections at approximately 235 deg. C, which requires further study and analysis. (author)

  19. Adequacy of annealing duration in reducing the background counts of personnel monitoring TLD cards - a study

    International Nuclear Information System (INIS)

    Srivastava, Kshama; Varadharajan, Geetha; Punekar, M.P.; Chougaokar, M.P.; Ayappan, P.

    2010-01-01

    In India, the personnel monitoring service of ∼ 70,000 radiation workers is being provided using indigenously developed TLD system comprising three CaSO 4 :Dy embedded Teflon discs. In order to remove TL and reset the distribution of defects/trapping centres, all TLD cards are subjected to an annealing treatment at elevated temperature prior to their next use. As per the standardized protocol annealing is carried out in a hot air circulating oven at 230 deg C for 4 hr, which is sufficient to reset the TL dosemeters for dose levels upto 100 mSv. In order to verify the appropriateness of annealing procedures adopted by the Laboratory, a detailed study was conducted using four sets of cards namely A, B, C and D series, exposed to various dose levels

  20. Further characteristics important in the operation of ceramic BeO TLD

    International Nuclear Information System (INIS)

    Gammage, R.B.

    1977-01-01

    There is now a considerable volume of published research dealing with ceramic BeO--TLD (Crase and Gammage, 1975; Yamashita et al., 1974; Scarpa et al., 1971). Its high sensitivity to radiation (1 mR), cheapness, commercial availability, non-toxicity, chemical stability, an atomic number of near tissue equivalence, and resistance to thermal fading, suggest that it should, by now, have found widespread acceptance as a TLD phosphor. It has not. There are only a small handful of reports dealing with the practical application of this type of dosimeter (Puite et al., 1974; Gammage and Haywood, 1976; Gesell et al., 1975). It seems wise, therefore, to look at the phosphor more closely and to focus on characteristics likely to cause problems under real operating conditions, especially those which are acting as a deterrent to its widespread acceptance. Operational characteristics were studied and the results are discussed

  1. Verification or treatment planning system of radiotherapy using TLD-100; Verificacion de los sistemas de planificacion de tratamiento de radioterapia empleando TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Pinuela, J., E-mail: jcpinuela@hotmail.co [Hospital Central de Maracay (Venezuela, Bolivarian Republic of). Servicio de Radioterapia

    2010-07-01

    The evaluation of the treatment planning system (TPS) used in radiotherapy Precise Plan, was carried out using TLD-100 dosimeters, comparing the dose obtained with an ionization chamber. The TLD-100 were calibrated using secondary standard of SSDL, selecting dosimeters which had a standard deviation less than 1% for dosimeter calibration and less than 5% for dosimeter of field, for the tests conducted in TPS, The Alderson Phantom was used to evaluate the wedge and bolus, and Lucy 3D allowed us to evaluate correspondence of CT numbers, volume expansion, beam shaping, precise dose and beam weigh assignment. It was observed that the results of Lucy 3D were within the values expected except the volume expansion process with more than 10% difference, the evaluation of beam modulators systems with wedges and bolus as beam shaping yielded values within the expected with variations less than 5% and to assess the supply of specific doses, it was observed that the values obtained were precise and accurate since the same variation was less than 0.5% for the test. The importance of assessing the TPS lies in our country there is no procedure to verify that system and these tests provide a basis for future comparisons. (author)

  2. Measurement of high natural background radiation levels by TLD at Cox's Bazar coastal areas in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.; Rahman, M.M.; Koddus, M.A.; Husain, S.R.; Malek, M.A.

    1987-01-01

    High natural background radiation levels at the Cox's Bazar coastal areas in Bangladesh were measured by LiF (TLD-100) dosemeters. The dose rates varied from 2621 to 35391 μGy.y -1 with a mean of 11968 μGy.y -1 . The average dose rate is found to significantly higher than the world average value. In order to formulate appropriate guidelines for radiation protection of the population in this area, the necessary recommendations are described. (author)

  3. Performance testing of the environmental TLD system for the Three Mile Island Nuclear Station.

    Science.gov (United States)

    Toke, L F; Carson, B H; Baker, G G; McBride, M H; Plato, P A; Miklos, J A

    1984-05-01

    Panasonic UD-801 thermoluminescent dosimeters ( TLDs ) containing two calcium sulfate phosphors were tested under Performance Specification 3.1 established by the American National Standard Institute ( ANSI75 ) and in the U.S. Nuclear Regulatory Commission's Regulatory Guide 4.13 ( NRC77 ). The specific qualifying tests included TLD uniformity, reproducibility, energy dependence and directional dependence. The overall measurement uncertainties and associated confidence levels are within the prescribed guidelines defined in the qualifying requirements for environmental TLDs .

  4. Evaluation of LiF:Mg,Ti (TLD-100 for Intraoperative Electron Radiation Therapy Quality Assurance.

    Directory of Open Access Journals (Sweden)

    Raffaele Liuzzi

    Full Text Available Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs response to intraoperative electron radiation therapy (IOERT beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2-12 cGy/pulse during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.LiF:Mg,Ti dosimeters (TLD-100 were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0-10 Gy in step of 2 Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.The TLD-100 dose-response curves were obtained. In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05.This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.

  5. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue

  6. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    Energy Technology Data Exchange (ETDEWEB)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford`s mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  7. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    Energy Technology Data Exchange (ETDEWEB)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  8. Assessment of radiation exposure of nuclear medicine staff using personal TLD dosimeters and charcoal detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, F.; Garcia-Talavera, M.; Pardo, R.; Deban, L. [Valladolid Univ., Dept. de Quimica Analitica, Facultad de Ciencias (Spain); Garcia-Talavera, P.; Singi, G.M.; Martin, E. [Hospital Clinico Univ., Servicio de Medicina Nuclear, Salamanca (Spain)

    2006-07-01

    Although the main concern regarding exposure to ionizing radiation for nuclear medicine workers is external radiation, inhalation of radionuclides can significantly contribute to the imparted doses. We propose a new approach to assess exposure to inhalation of {sup 131}I based on passive monitoring using activated charcoal detectors. We compared the inhalation doses to the staff of a nuclear medicine department, based on the measurements derived from charcoal detectors placed at various locations, and the external doses monitored using personal TLD dosimeters. (authors)

  9. Assessment of radiation exposure of nuclear medicine staff using personal TLD dosimeters and charcoal detectors

    International Nuclear Information System (INIS)

    Jimenez, F.; Garcia-Talavera, M.; Pardo, R.; Deban, L.; Garcia-Talavera, P.; Singi, G.M.; Martin, E.

    2006-01-01

    Although the main concern regarding exposure to ionizing radiation for nuclear medicine workers is external radiation, inhalation of radionuclides can significantly contribute to the imparted doses. We propose a new approach to assess exposure to inhalation of 131 I based on passive monitoring using activated charcoal detectors. We compared the inhalation doses to the staff of a nuclear medicine department, based on the measurements derived from charcoal detectors placed at various locations, and the external doses monitored using personal TLD dosimeters. (authors)

  10. TLD gamma-ray energy deposition measurements in the zero energy fast reactor ZEBRA

    International Nuclear Information System (INIS)

    Knipe, A.D.

    1977-01-01

    A recent study of gamma-ray energy deposition was carried out in the Zebra reactor at AEE Winfrith during a collaborative programme between the UKAEA and PNC of Japan. The programme was given the title MOZART. This paper describes the TLD experiments in the MOZART MZB assembly and discusses the technique and various corrections necessary to relate the measured quantity to the calculated energy deposition

  11. Measurement of exposure dose rate by TLD in 60Co garden

    International Nuclear Information System (INIS)

    Fan Chengfang; Li Pinfang; Wu Maoliang; Zhao Quan

    1987-01-01

    The use of TLD method to measure exposure dose rate in 60 Co garden is described. As compared with chemical dosimetry, the relative deviation of measurement would not exceed 10%. The good repeatability has been proved by comparing the measurements of different times and distances with correction of decay law and 1/1 2 law. Besides, the distribution of exposure dose rate was influenced by scattering of the living plants

  12. Teaching the Total Language with Readers Theatre.

    Science.gov (United States)

    Goodman, Jess A., Jr.

    Reading, writing, speech assignments for special education classes, English as a second language and many other classroom projects can be taught through the involvement created by Readers Theatre. Readers Theatre is the presentation of dialogue-type material in play form. The actors hold the script as they move through it and a narrator's voice…

  13. Planning Behaviour in Good and Poor Readers

    Science.gov (United States)

    Mahapatra, Shamita

    2016-01-01

    A group of 50 good readers and a group of 50 poor readers of Grade 5 matched for age and intelligence and selected on the basis of their proficiency in reading comprehension were tested for their competence in word reading and the process of planning at three different levels, namely, perceptual, memory and conceptual in order to study the…

  14. Reader responses to literary depictions of rape

    NARCIS (Netherlands)

    E.M. Koopman (Emy); M. Hilscher (Michelle); G.C. Cupchik (Gerald)

    2012-01-01

    textabstractThis study explored reader responses to different literary depictions of rape. Four literary excerpts were used and divided as aesthetic versus nonaesthetic (style) and allusive versus explicit (detail). The general question was how readers would react to literary fragments depicting

  15. Using Readers' Theater with Multicultural Literature

    Science.gov (United States)

    Weisenburger, Stephanie

    2009-01-01

    The author needed a way to engage her students in the reading process and found one extremely successful strategy: using Readers' Theater. Readers' Theater "dramatizes" literature through a classroom performance and provides visual and oral stimulus to students who are not used to using imagination to appreciate literary texts. It involves a…

  16. Postmodern theories about readers in electronic environment

    Directory of Open Access Journals (Sweden)

    Ivanka Kuić

    2015-03-01

    Full Text Available Introductory part of the paper discusses theories about readers in the last decades of the 20th century. In particular, two big theoretical schools are discussed: aesthetic reception theory and reader-response-criticism movement. Readers are a subject of very different scientific disciplines: literature theory, sociology, anthropology, book history and library science. The idea that a reader is an essential subject for future life of a literary work is common to all theorists. By constructing the theory about a reader, theorists have thought about the reader who uses the conventions of printed text. The issue whether these concepts correspond to electronic surroundings is discussed. Characteristics of the hypertext are emphasized as a new paradigm, and also the issue weather readers enjoys in hypertextual fiction. In conclusion, paper expands the virtual dimension of Isers's theory about interaction between the text and the reader, and also Fish's concept of “interpretative community” which may be constituted on the Internet as a flexible virtual community.

  17. Readers Theatre plus Comprehension and Word Study

    Science.gov (United States)

    Young, Chase; Stokes, Faida; Rasinski, Timothy

    2017-01-01

    Readers Theatre has been used to introduce critical issues, promote fluency among English learners and non-English learners, teach vocabulary, and integrate content in the classroom. Previous studies of Readers Theatre application have demonstrated an increase in student reading fluency, motivation, and confidence. The focus of this systemic…

  18. The active reader: what is active?

    NARCIS (Netherlands)

    Woerkum, van C.

    2012-01-01

    How writers can adapt to their readers is an important issue in effective communication strategies, and certainly crucial in the case of functional texts. Therefore, it is necessary to look at how readers are constructed as partners in a communication co-production. This article explores the concept

  19. Practicum Training for Teachers of Struggling Readers

    Science.gov (United States)

    Morris, Darrell

    2011-01-01

    Teachers who work with struggling beginning readers need a supervised training experience that leads them to understand both how reading ability develops and how to adapt instruction to meet the needs of individual children. The practicum, in which a teacher works with one struggling reader under the supervision of an experienced and expert…

  20. The evaluation of dose of TSEI with TLD and diode detector of the uterine cervix cancer

    International Nuclear Information System (INIS)

    Je, Young Wan; Na, Keyung Su; Yoon, Il Kyu; Park, Heung Deuk

    2005-01-01

    To evaluate radiation dose and accuracy with TLD and diode detector when treat total skin with electron beam. Using Stanford Technique, we treated patient with Mycosis Fungoides. 6 MeV electron beam of LINAC was used and the SSD was 300 cm. Also, acrylic speller(0.8 cm) was used. The patient position was 6 types and the gantry angle was 64, 90 and 116 degree. The patient's skin dose and the output were detected 5 to 6 times with TLD and diode. The deviations of dose detected with TLD from tumor dose were CA + 6%, thigh + 8%, umbilicus + 4%, calf - 8%, vertex - 74.4%, deep axillae - 10.2%, anus and testis - 87%, sole - 86% and nails shielded with 4 mm lead + 4%. The deviations of dose detected with diode were - 4.5% ∼ + 5% at the patient center and - 1.1% ∼ + 1% at the speller. The deviation of total skin dose was + 8% ∼ - 8% and that deviation was within the acceptable range(±10%). The boost dose was irradiated for the low dose areas(vertex, anus, sole). The electron beam output detected at the sootier was stable. It is thought that the deviation of dose at patient center detected with diode was induced by detection point and patient position.

  1. Comparative study of trapping parameters of LiF(TLD-100) from different production batches

    Energy Technology Data Exchange (ETDEWEB)

    Bos, A.J.J.; Piters, T.M.; Vries, W. de; Hoogenboom, J.E. (Delft Univ. of Technology (Netherlands). Interfaculty Reactor Institute)

    1990-01-01

    Computerised glow curve analysis has been used to determine the trapping parameters of the main peaks of the thermoluminescent (TL) material LiF(TLD-100). The TL material (solid state chips) originated from six different production batches with at least 19 chips per batch. The maxima of glow peaks 2 to 5 are found at the same temperature within very small limits. The activation energy and frequency factor of the main glow peak (peak 5) of TLD-100 originating from two batches differ significantly from those of the other four investigated batches. Nevertheless, the sensitivity of glow peak 5 is more or less the same for all batches. The trapping parameters of glow peaks 2 to 4 of TLD-100 vary little from batch to batch. The measured half-life of peak 2 differed strongly from batch to batch. For all investigated peaks no correlation has been found between glow peak sensitivity and trapping parameters. The results of this study suggest that both defect concentration and nature of the trapping centres vary from batch to batch. It would appear that as a consequence of selection by the manufacturer, the differences between the batches in terms of total light output are small. (author).

  2. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  3. 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.

  4. The effect of the build-up wall at the TLD calibration using Co-60

    International Nuclear Information System (INIS)

    Nariyama, N.

    2000-01-01

    Absorbed dose in thermoluminescent dosimeter (TLD) material at the calibration using Co-60 gamma rays depends on the TLD thickness and the wall material used for electric equilibrium condition. The relation was examined for LiF, BeO and CaF 2 TLDs sandwiched with PMMA, Teflon and Pyrex glass walls using a Monte Carlo transport code and compared with cavity ionization theory calculations. For the mismatched combination of LiF, BeO/Pyrex glass and CaF 2 /PMMA, it was found that the energy deposition did not change monotonously with TLD thickness from small cavity to large cavity value: a depression observed around 1-mm thickness for LiF/Pyrex glass and a peak around 0.6-mm thickness for CaF 2 /PMMA. The phenomena were explained by using different exponential attenuation coefficients β and β' for the weighting functions of cavity theory. Moreover, use of large cavity values was found to lead possibly to 3-5% errors in the calibration of thin TLDs. (author)

  5. Alanine and TLD coupled detectors for fast neutron dose measurements in neutron capture therapy (NCT)

    Energy Technology Data Exchange (ETDEWEB)

    Cecilia, A.; Baccaro, S.; Cemmi, A. [ENEA-FIS-ION, Casaccia RC, Via Anguillarese 301, 00060 Santa Maria di Galeria, Rome (Italy); Colli, V.; Gambarini, G. [Dept. of Physics of the Univ., INFN, Via Celoria 16, 20133 Milan (Italy); Rosi, G. [ENEA-FIS-ION, Casaccia RC, Via Anguillarese 301, 00060 Santa Maria di Galeria, Rome (Italy); Scolari, L. [Dept. of Physics of the Univ., INFN, Via Celoria 16, 20133 Milan (Italy)

    2004-07-01

    A method was investigated to measure gamma and fast neutron doses in phantoms exposed to an epithermal neutron beam designed for neutron capture therapy (NCT). The gamma dose component was measured by TLD-300 [CaF{sub 2}:Tm] and the fast neutron dose, mainly due to elastic scattering with hydrogen nuclei, was measured by alanine dosemeters [CH{sub 3}CH(NH{sub 2})COOH]. The gamma and fast neutron doses deposited in alanine dosemeters are very near to those released in tissue, because of the alanine tissue equivalence. Couples of TLD-300 and alanine dosemeters were irradiated in phantoms positioned in the epithermal column of the Tapiro reactor (ENEA-Casaccia RC). The dosemeter response depends on the linear energy transfer (LET) of radiation, hence the precision and reliability of the fast neutron dose values obtained with the proposed method have been investigated. Results showed that the combination of alanine and TLD detectors is a promising method to separate gamma dose and fast neutron dose in NCT. (authors)

  6. Evaluation of mixed energy neutron doses using TLD NG-67 type

    International Nuclear Information System (INIS)

    Akhadi, Mukhlis; Thoyib Thamrin, M; Usmiyati Dewi, K.

    2000-01-01

    A research has been carried out to develop dose evaluation method of mixed neutron source with its neutron doses can be classified to two groups, I.e neutron doses with energy ≥ 0.5 eV and thermal neutron doses with energy less than 0.5 e V consist of epithermal and fast neutron, but in this research they were classified as fast neutron. Development of this dose evaluation method was carried out by sensitivity (S) intercomparison of TLD-600 to fast neutron, mixed energy neutron of nuclear rectors, and thermal neutron. From the experiment it was obtained that the value of Sfast : Sreactor : Sthermal = 0.005 : 0.010 : 1. Calibration factor (CF) of TLD is defined as 1/S. from the sensitivity data it can be obtained that the value of Cffast : Cfreactor : Cfthermal = 200 :100 : 1. The value of Cfreactor can be applied for mixed energy neutron doses evaluation of TLD-600. Key word : dosemeter, neutron dose, calibration factor, fast neutron, thermal neutron, nuclear reactor

  7. Cyber Literature: A Reader – Writer Interactivity

    Directory of Open Access Journals (Sweden)

    Fathu Rahman

    2017-06-01

    Full Text Available Cyber Literature is a term known since the coming of the internet which brings a convenience, changing habit and world view. This study is a survey-based on respondents’ opinion about the existence of cyber literature on social media; of its benefit and impact to the reader. This study limits to the poems on Facebook group. The reason is simple; it favors the short form. For the study of a reader-writer interactivity in cyber literature is more likely on poetry. The approach is reader response literary theory with focus on the reader-writer interactivity on Facebook. This research aimed at uncovering the motivation of readers to response the uploaded text, the reasons why they love it and what its advantages. The results showed that cyber literature is successfully to introduce a new literary genre as well as to raise motivation and creativity of authors to make use the internet space.

  8. Development of an automatic identification algorithm for antibiogram analysis

    OpenAIRE

    Costa, LFR; Eduardo Silva; Noronha, VT; Ivone Vaz-Moreira; Olga C Nunes; de Andrade, MM

    2015-01-01

    Routinely, diagnostic and microbiology laboratories perform antibiogram analysis which can present some difficulties leading to misreadings and intra and inter-reader deviations. An Automatic Identification Algorithm (AIA) has been proposed as a solution to overcome some issues associated with the disc diffusion method, which is the main goal of this work. ALA allows automatic scanning of inhibition zones obtained by antibiograms. More than 60 environmental isolates were tested using suscepti...

  9. A study on dose attenuation in bone density when TBI using diode detector and TLD

    International Nuclear Information System (INIS)

    Im, Hyun Sil; Lee, Jung Jin; Jang, Ahn Ki; KIm, Wan Sun

    2003-01-01

    Uniform dose distribution of the whole body is essential factor for the total body irradiation(TBI). In order to achieved this goal, we used to compensation filter to compensate body contour irregularity and thickness differences. But we can not compensate components of body, namely lung or bone. The purpose of this study is evaluation of dose attenuation in bone tissue when TBI using diode detectors and TLD system. The object of this study were 5 patients who undergo TBI at our hospital. Dosimetry system were diode detectors and TLD system. Treatment method was bilateral and delivered 10 MV X-ray from linear accelerator. Measurement points were head, neck, pelvis, knees and ankles. TLD used two patients and diode detectors used three patients. Results are as followed. All measured dose value were normalized skin dose. TLD dosimetry : Measured skin dose of head, neck, pelvis, knees and ankles were 92.78±3.3, 104.34±2.3, 98.03±1.4, 99.9±2.53, 98.17±0.56 respectably. Measured mid-depth dose of pelvis, knees and ankles were 86±1.82, 93.24±2.53, 91.50±2.84 respectably. There were 6.67%-11.65% dose attenuation at mid-depth in pelvis, knees and ankles. Diode detector : Measured skin dose of head, neck, pelvis, knees and ankles were 95.23±1.18, 98.33±0.6, 93.5±1.5, 87.3±1.5, 86.90±1.16 respectably. There were 4.53%-12.6% dose attenuation at mid-depth in pelvis, knees and ankles. We concluded that dose measurement with TLD or diode detector was inevitable when TBI treatment. Considered dose attenuation in bone tissue, We must have adequately deduction of compensator thickness that body portion involved bone tissue.

  10. Recommendations: Introducing the quality system into the use of significant ionizing radiation sources in radiotherapy. TLD audit by mail within the quality system in radiotherapy

    International Nuclear Information System (INIS)

    Ekendahl, D.; Valenta, J.; Horakova, I.

    2005-01-01

    The publication consists of the following sections: TLD measurement methodology (Description of the TLD system; Dose determination); TLD audit in radiotherapy: methodologies and evaluation of results (Checking the dose calculated by the planning system and beam quality control; Checking the calculated dose distribution using a versatile phantom; Checking the calculated doses for linear accelerators with multilammelar collimators; Evaluation and analysis of results; Organizing a performing audits by mail); and Annexes: Detailed guidelines and protocols for radiotherapy departments. (P.A.)

  11. Process Synchronization with Readers and Writers Revisited

    OpenAIRE

    Kawash, Jalal

    2005-01-01

    The readers-writers problem is one of the very well known problems in concurrency theory. It was first introduced by Courtois et.al. in 1971 [1] and requires the synchronization of processes trying to read and write a shared resource. Several readers are allowed to access the resource simultaneously, but a writer must be given exclusive access to that resource. Courtois et.al. gave semaphore-based solutions to what they called the first and second readers-writers problems. Both of their solut...

  12. Reasons for deviations outside the acceptance limits in the IAEA/WHO TLD audits for radiotherapy hospitals

    International Nuclear Information System (INIS)

    Vatnitsky, Stanislav; Izewska, Joanna

    2002-01-01

    The main purpose of the IAEA/WHO TLD postal dose audit programme for dosimetry in radiotherapy [1] is to provide an independent verification of the dose delivered by treatment machines in radiotherapy hospitals. The results of the TLD audit are considered acceptable if the relative deviation between the participant's stated dose and the TLD determined dose is within ±5%. The goal of this note is to draw the attention of participants of the TLD programme to some of the common reasons for deviations outside the acceptance limits. Armed with this knowledge, other participants may avoid similar problems in the future. The analysis of deviations presented here is based on the results of TLD audits of the calibration of approximately 1000 Co-60 beams and 600 high-energy X-ray beams performed in the period 1996-2001. A total of 259 deviations outside the ±5% limits have been detected, including 204 deviations for Co-60 beams (20% of all Co-60 beams checked) and 55 for high-energy X-ray beams (10% of all X-ray beams checked). It is worth mentioning that the percentage of large deviations (beyond 10%) is also higher for Co-60 beams than for highenergy X-ray beams. Some problems may be caused by obsolete dosimetry equipment or poor treatment machine conditions. Other problems may be due to insufficient training of staff working in radiotherapy. The clinical relevance of severe TLD deviations detected in the audit programme was confirmed in many cases, but, fortunately, not all-poor dosimetric results reflect deficiencies in the calibration of clinical beams or machine faults. Sometime it happens, that the TLDs are irradiated with an incorrect dose due to misunderstanding of the instructions on how to perform the TLD irradiation. Such dosimetry errors would have no direct impact on actual dose delivered to a patient

  13. Comparison of wrist and head TLD doses with whole body TLD doses during high active jobs at RAPS-5 and 6

    International Nuclear Information System (INIS)

    Sharma, Ravi Kant; Abhishek, Neel; Kakkar, Amandeep; Kumar, Rajesh

    2016-01-01

    In nuclear power plant radiation dose monitoring and assessment is done to control the individual dose and station collective doses. While performing a radioactive job on systems or equipment with significant radiation levels of non uniform and beaming radiation; there is potential of localized exposure to extremities hands in particular and lens of the eye in comparison to other body parts. Keeping in view of this, separate equivalent dose limit to the extremities (hands and feet) and lens of the eye are defined by ICRP. A study has been carried out during Biennial Shutdown (BSD) of RAPS-6 in the month of October-2015 to establish the correlation between the doses received by chest TLDs which is being used to estimate the effective whole body dose of the radiation worker and the doses received in wrist TLD and head TLDs which are being used to monitor the equivalent dose received by hands and lens of the eye with applying a suitable correction factor

  14. Breast cancer MRI radiomics: An overview of algorithmic features and impact of inter-reader variability in annotating tumors.

    Science.gov (United States)

    Saha, Ashirbani; Harowicz, Michael R; Mazurowski, Maciej A

    2018-04-16

    To review features used in MRI radiomics of breast cancer and study the inter-reader stability of the features METHODS: We implemented 529 algorithmic features that can be extracted from tumor and fibroglandular tissue (FGT) in breast MRIs. The features were identified based on a review of the existing literature with consideration of their usage, prognostic ability, and uniqueness. The set was then extended so that it comprehensively describes breast cancer imaging characteristics. The features were classified into 10 groups based on the type of data used to extract them and the type of calculation being performed. For the assessment of inter-reader variability, 4 fellowship-trained readers annotated tumors on pre-operative dynamic contrast enhanced MRIs for 50 breast cancer patients. Based on the annotations, an algorithm automatically segmented the image and extracted all features resulting in one set of features for each reader. For a given feature, the inter-reader stability was defined as the intra-class correlation coefficient (ICC) computed using the feature values obtained through all readers for all cases. The average inter-reader stability for all features was 0.8474 (95% CI: 0.8068-0.8858). The mean inter-reader stability was lower for tumor-based features (0.6348, 95% CI: 0.5391-0.7257) than FGT-based features (0.9984, 95% CI: 0.9970-0.9992). The feature group with the highest inter-reader stability quantifies breast and FGT volume. The feature group with the lowest inter-reader stability quantifies variations in tumor enhancement. Breast MRI radiomics features widely vary in terms of their stability in the presence of inter-reader variability. Appropriate measures need to be taken for reducing this variability in tumor-based radiomics. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. Program for control and editing the output data of spiral reader

    International Nuclear Information System (INIS)

    Yamburenko, V.S.

    1983-01-01

    The program forming the magnetic tape with outpug data of Spiral Reader from that one containing initial data for computing on big computers is desribed. The program is controlled by ''operator-computer'' dialogue using the HT-340 display. During rewriting the data structure and quality are checked. Manual and automatic modes of rewriting are possible. The editing mode permits to create easily arrays of data of a given format. The magnetic tapes format and data structure are also described

  16. Cultural Journalism Publications for Reluctant Readers.

    Science.gov (United States)

    Hatcher, Barbara

    1980-01-01

    Provides a list of cultural journalism publications (based on oral history interviews) written, edited, and produced by students around the country that provide good easy reading for older reluctant readers. (MKM)

  17. Face-to-face with the reader

    Directory of Open Access Journals (Sweden)

    Tatiana KAIGORODOVA

    2016-03-01

    Full Text Available Thank you for inviting me to this meeting. I understood that it is a meeting of the editorial board with readers. But I would like to note that there is still such a small layer between the editors and readers, which is called the printing house. So it is the typography that materially embodies the ideas, thoughts and innovations of the editorial staff and the authors.

  18. New IoT proximity service based heterogeneous RFID readers collision control

    Directory of Open Access Journals (Sweden)

    Jose Ignacio Tamayo Segarra

    2017-08-01

    Full Text Available Purpose – Internet of Things’ (IoT’s first wave started with tracking services for better inventory management mainly using radio frequency identification (RFID technology. Later on, monitoring services became one of the major interests, including sensing technologies, and then more actuation for remote control-type of IoT applications such as smart homes, smart cities and Industry 4.0. In this paper, the authors focus on the RFID technology impairment. They propose to take advantage of the mature IoT technologies that offer native service discovery such as blutooth or LTE D2D ProSe or Wifi Direct. Using the automatic service discovery in the new framework will make heterogeneous readers aware of the presence of other readers and this will be used by the proposed distributed algorithm to better control the multiple RFID reader interference problem. The author clearly considers emerging Industry 4.0 use case, where RFID technology is of major interest for both identification and tracking. To enhance the RFID tag reading performance, collisions in the RFID frequency should be minimized with reader-to-reader coordination protocols. In this paper, the author proposes a simple distributed reader anti-collision protocol named DiSim that makes use of proximity services of IoT network and is compliant with the current RFID standards. The author evaluates the efficiency of the proposal via simulation. Design/methodology/approach – In this paper, the author proposes a simple distributed reader anti-collision protocol named DiSim that makes use of proximity services of IoT network and is compliant with the current RFID standards. The author evaluates the efficiency of the proposal via simulation to study its behavior in very dense and heterogeneous RFID environments. Specifically, the author explores the coexistence of powerful static readers and small mobile readers, comparing the proposal with a standard ETSI CSMA method. The proposal reduces

  19. A quality control program for the thermoluminescence dosimeter (TLD) in personnel radiation monitoring

    International Nuclear Information System (INIS)

    Seo, Kyung Won; Kim, Jang Lyul; Lee, Sang Yoon; Lee, Hyung Sub

    1994-01-01

    High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The ministry of science and technology (MOST) issued a ministerial ordinance (No 199-15) about the technical criteria on personnel dosimeter processors on 1992. The purpose of this quality control program is to prescribe the procedures approved by the management of KAERI for implementing a quality badge service by means of TLD for personnel working in an area where they may be exposed to ionization radiation. (Author) 10 refs

  20. Thermoluminescent relative efficiencies of TLD-100 for nitrogen ions respect of gamma radiation

    International Nuclear Information System (INIS)

    Concha S, K.; Avila, O.; Gamboa de Buen, I.; Rodriguez V, M.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E.

    2004-01-01

    The purpose of this work is to measure the thermoluminescent relative efficiency of those TLD-100 dosemeters irradiated with nitrogen ions with respect to the gamma radiation of 60 Co, in function of the linear energy transfer (LET). Two energy of such nitrogen ions were selected that has the same value from LET when impacting in the dosemeters but with E 1 energy (4.8 MeV) and E 2 (9.95 MeV) smaller and greater respectively that the energy of the Bragg peak. (Author)

  1. TLD Quality Assurance (QA) network in radiotherapy and radiology in the Czech Republic

    International Nuclear Information System (INIS)

    Kroutilikova, D.; Novak, N.; Novotny, J.

    2002-01-01

    Full text: The Czech TLD QA network was established in 1997, as a part of the External Auditing Group (EAG) originated in 1995, in order to perform an independent quality audit in external beam therapy for two purposes: a) to unify the dose within radiotherapy departments, b) to impact state supervision. On basis of a good experience with this network in radiotherapy, new methods were developed to expand the network also to radiology in order to simplify the operation of state supervision. The TLD QA network in dental radiology has been brought into practice in 2001. Both the TLD audits performed in radiotherapy and radiology are realized via mailed dosimetry. In radiotherapy, two modes of the audit are used. Basic mode of TLD audit covers measurements under reference conditions, specifically beam calibration checks for all clinically used photon and electron beams. According to Czech regulations every beam must be checked in this way at least once during two years' period. Advanced mode consists of measurements under both reference and non- reference conditions using Leuven multi-purpose phantom for photon beams. It enables to check a substantial part of the treatment planning process inclusive of final dose realization of the planned radiotherapy. The radiotherapy centers are instructed to deliver absorbed dose of 2 Gy to the TLDs on central beam axis based on calculated treatment time or monitor units by their treatment planning system for a particular treatment set-up. In this way the TLD measured doses are compared with the calculated ones. Deviations of ±3% are considered acceptable for both basic and advanced modes of the audit, deviations up to ±6% are still tolerable, but new audit is repeated as soon as possible to solve the dosimetry problem. Deviations above ±6% leads immediately to investigation by EAG. There are 34 centers in the Czech Republic, which provide external beam radiotherapy. Since they must undergo the basic TLD audit regularly every

  2. Evaluation of the breast plan using the TLD and MOSFET for the skin dose

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seon Myeong; Kim, Young Bum; Bak, Sang Yun; Lee, Sang Rok; Jeong, Se Young [Dept. of Radiation Oncology, Korea University Ansan Hospital, Ansan (Korea, Republic of)

    2015-12-15

    The measurement of skin dose is very important that treatment of breast cancer. On account of the cold or hot dose as compared with prescription dose, it is necessary to analyse the skin dose occurring during the various plan of the breast cancer treatment. At our hospital, we want to apply various analyses using a diversity of dosimeters to the breast cancer treatment. In the study, the anthropomorphic phantom is used to find out the dose difference of the skin(draining site), scar and others occurring from the tangential treatment plan of breast cancer. We took computed tomography scan of the anthropomorphic phantom and made plans for the treatment planing using open and wedge, Field-in-Field, Dose fluence. Using these, we made a comparative analysis of the dose date points by using the Eclipse. For the dose comparison, we place the anthropomorphic phantom in the treatment room and compared the measurement results by using the TLD and MOSFET on the dose data points. On the central point of treatment planing basis, the upward and downward skin dose measured by the MOSFET was the highest when the fluence was used. The skin dose of inner and outer was distinguished from the figure(5.7% - 10.3%) when the measurements were fulfilled by using TLD and MOSFET. The other side of breast dose was the lowest in the open beam, on the other hand, is highest in the Dose fluence plan. In the different kinds of treatment, the dose deviation of inner and outer was the highest, and so this was the same with the TLD and MOSFET measurement case. The outer deviation was highest in the TLD, and the Inner' was highest in the MOSFET. Skin dose in relation to the treatment plan was the highest in the planing using the fluence technique in general and it was supposed that the high dose had been caused by the movement of the MLC. There's some differences among the all the treatment planning, but the sites such as IM node occurring the lack of dose, scar, drain site are needed pay

  3. Evaluation of the breast plan using the TLD and MOSFET for the skin dose

    International Nuclear Information System (INIS)

    Kim, Seon Myeong; Kim, Young Bum; Bak, Sang Yun; Lee, Sang Rok; Jeong, Se Young

    2015-01-01

    The measurement of skin dose is very important that treatment of breast cancer. On account of the cold or hot dose as compared with prescription dose, it is necessary to analyse the skin dose occurring during the various plan of the breast cancer treatment. At our hospital, we want to apply various analyses using a diversity of dosimeters to the breast cancer treatment. In the study, the anthropomorphic phantom is used to find out the dose difference of the skin(draining site), scar and others occurring from the tangential treatment plan of breast cancer. We took computed tomography scan of the anthropomorphic phantom and made plans for the treatment planing using open and wedge, Field-in-Field, Dose fluence. Using these, we made a comparative analysis of the dose date points by using the Eclipse. For the dose comparison, we place the anthropomorphic phantom in the treatment room and compared the measurement results by using the TLD and MOSFET on the dose data points. On the central point of treatment planing basis, the upward and downward skin dose measured by the MOSFET was the highest when the fluence was used. The skin dose of inner and outer was distinguished from the figure(5.7% - 10.3%) when the measurements were fulfilled by using TLD and MOSFET. The other side of breast dose was the lowest in the open beam, on the other hand, is highest in the Dose fluence plan. In the different kinds of treatment, the dose deviation of inner and outer was the highest, and so this was the same with the TLD and MOSFET measurement case. The outer deviation was highest in the TLD, and the Inner' was highest in the MOSFET. Skin dose in relation to the treatment plan was the highest in the planing using the fluence technique in general and it was supposed that the high dose had been caused by the movement of the MLC. There's some differences among the all the treatment planning, but the sites such as IM node occurring the lack of dose, scar, drain site are needed pay

  4. Interpretation of TLD data measured in the vicinity of nuclear power plants

    International Nuclear Information System (INIS)

    Czarnecki, J.; Baggenstos, M.; Schuler, J.; Voelkle, H.

    1981-01-01

    It is shown that incorporating the location-specific characteristics of natural radiation into the interpretation of the surrounding measurements makes some valuable contributions to the improvement of the measuring quality of thermoluminescent enviromental dosimetry. This brings the possibility to determine the net dose of the additional man-made radiations (e.g. caused by the nuclear power plant) with better accuracy. The authors propose a method of analysing the measured results which enables one to include the measured data from the evidence finding phase in the interpretation of the environment monitoring-TLD-measurement (orig./DG) [de

  5. Development of fuel number reader by ultrasonic imaging techniques

    International Nuclear Information System (INIS)

    Omote, T.; Yoshida, T.

    1991-01-01

    This paper reports on a spent fuel ID number reader using ultrasonic imaging techniques that has been developed to realize efficient and automatic verification of fuel numbers, thereby to reduce mental load and radiation exposure for operators engaged in the verification task. The ultrasonic imaging techniques for automatic fuel number recognition are described. High-speed and high reliability imaging of the spent fuel ID number are obtained by using linear array type ultrasonic probe. The ultrasonic wave is scanned by switching array probe in vertical direction, and scanned mechanically in horizontal direction. Time for imaging of spent fuel ID number on assembly was confirmed less than three seconds by these techniques. And it can recognize spent fuel ID number even if spent fuel ID number can not be visualized by an optical method because of depositing fuel number regions by soft card. In order to recognize spent fuel ID number more rapidly and more reliably, coded fuel number expressed by plural separate recesses form is developed. Every coded fuel number consists of six small holes (about 1 mm dia.) and can be marked adjacent to the existing fuel number expressed by letters and numbers

  6. Unusual ratio of TL readouts of different discs of personnel monitoring TLD badge based on CaSO4: Dy teflon disc

    International Nuclear Information System (INIS)

    Pradhan, S.M.; Ande, C.D.; Kher, R.K.; Chourasiya, G.; Vashishtha, R.; Gupta, A.K.

    2005-01-01

    In India Personnel Monitoring against external radiation hazard of gamma, beta and X-rays is provided using a TLD badge based on CaSO 4 : Dy Teflon TLD disc. Unusual ratios of TL readouts of different discs of TLD badge (Disc Ratios) observed for service TLD badges of radiation workers were investigated and simulated. Simulations were carried out by exposure of TLD badges by speck type radioactive sources placed in contact of badges, exposure of TLD badges placed on concrete floor to a radiography source. Clues for the simulation were obtained from nature of work, radiological conditions during course of individuals' work whose TLD badges showed the unusual disc ratios and geometrical calculations performed. It is concluded that although the actual exposure condition during use is unknown, the unusual disk ratios observed for the service TLD badges can be simulated and utilized to arrive at probable exposure conditions. The study helped in investigations of the abnormal exposures and assigning doses to the concerned radiation workers. (author)

  7. E-Book Readers in Higher Education

    Directory of Open Access Journals (Sweden)

    Arthur N. Olsen

    2013-04-01

    Full Text Available This article reports on a research project at the University of Agder that has studied the use of e-readers as a tool for academic study. E-readers (Kindle DX and iPad were loaded with texts from required reading lists in five courses with 94 participating students. Initially, 87 students responded to the invitation to participate in a survey, but eventually 13 of these submissions had to be removed, as the degree of completion was not sufficient. The final response rate achieved was 79%. Students were in general positive to the use of e-readers but still show a preference for print on paper as the best medium for serious academic study. When reading books, 54% preferred print, 28% a combination of print and e-reader, and finally only 11% were satisfied solely using an e-reader. The iPad scored significantly better than the Kindle DX on tasks that required active interaction with the texts such as highlighting and note taking.

  8. Development of a TLD mailed system for remote dosimetry audit for 192Ir HDR and PDR sources

    International Nuclear Information System (INIS)

    Roue, Amelie; Venselaar, Jack L.M.; Ferreira, Ivaldo H.; Bridier, Andre; Dam, Jan van

    2007-01-01

    Background and purpose: In the framework of an ESTRO ESQUIRE project, the BRAPHYQS Physics Network and the EQUAL-ESTRO laboratory have developed a procedure for checking the absorbed dose to water in the vicinity of HDR or PDR sources using a mailed TLD system. The methodology and the materials used in the procedure are based on the existing EQUAL-ESTRO external radiotherapy dose checks. Materials and methods: A phantom for TLD postal dose assurance service, adapted to accept catheters from different HDR afterloaders, has been developed. The phantom consists of three PMMA tubes supporting catheters placed at 120 degrees around a central TLD holder. A study on the use of LiF powder type DTL 937 (Philitech) has been performed in order to establish the TLD calibration in dose-to-water at a given distance from 192 Ir source, as well as to determine all correction factors to convert the TLD reading into absorbed dose to water. The dosimetric audit is based on the comparison between the dose to water measured with the TL dosimeter and the dose calculated by the clinical TPS. Results of the audits are classified in four different levels depending on the ratio of the measured dose to the stated dose. The total uncertainty budget in the measurement of the absorbed dose to water using TLD near an 192 Ir HDR source, including TLD reading, correction factors and TLD calibration coefficient, is determined as 3.27% (1 s). Results: To validate the procedures, the external audit was first tested among the members of the BRAPHYQS Network. Since November 2004, the test has been made available for use by all European brachytherapy centres. To date, 11 centres have participated in the checks and the results obtained are very encouraging. Nevertheless, one error detected has shown the usefulness of this audit. Conclusion: A method of absorbed dose to water determination in the vicinity of an 192 Ir brachytherapy source was developed for the purpose of a mailed TL dosimetry system. The

  9. External assurance program in radiotherapy dose by TLD: implementation of a quality system and extension to complex treatments

    International Nuclear Information System (INIS)

    Mojsiejczuk, N.; Lohr, J.; Molina, L.; Vallejos, M.; Montaño, G.; Stefanic, A.; Zaretzky, A.

    2011-01-01

    Until now, the Regional Reference Center with secondary patterns for dosimetry ('Centro Regional de Referencia con Patrones Secundarios para Dosimetria' (CRRD)) has done dosimetry verifications with thermoluminescent dosimeters (TLD) in radiotherapy in square and rectangular fields. The objective of this paper is to inform about the first tests done to span new verification conditions in irradiations with multi-leaf collimator using regular and irregular field shapes. On the other hand, it will briefly describe the progress in the implementation of a quality management system adopted by the CRRD, regarding the TLD verification service. (author)

  10. Development of a TLD mailed system for remote dosimetry audit for (192)Ir HDR and PDR sources.

    Science.gov (United States)

    Roué, Amélie; Venselaar, Jack L M; Ferreira, Ivaldo H; Bridier, André; Van Dam, Jan

    2007-04-01

    In the framework of an ESTRO ESQUIRE project, the BRAPHYQS Physics Network and the EQUAL-ESTRO laboratory have developed a procedure for checking the absorbed dose to water in the vicinity of HDR or PDR sources using a mailed TLD system. The methodology and the materials used in the procedure are based on the existing EQUAL-ESTRO external radiotherapy dose checks. A phantom for TLD postal dose assurance service, adapted to accept catheters from different HDR afterloaders, has been developed. The phantom consists of three PMMA tubes supporting catheters placed at 120 degrees around a central TLD holder. A study on the use of LiF powder type DTL 937 (Philitech) has been performed in order to establish the TLD calibration in dose-to-water at a given distance from (192)Ir source, as well as to determine all correction factors to convert the TLD reading into absorbed dose to water. The dosimetric audit is based on the comparison between the dose to water measured with the TL dosimeter and the dose calculated by the clinical TPS. Results of the audits are classified in four different levels depending on the ratio of the measured dose to the stated dose. The total uncertainty budget in the measurement of the absorbed dose to water using TLD near an (192)Ir HDR source, including TLD reading, correction factors and TLD calibration coefficient, is determined as 3.27% (1s). To validate the procedures, the external audit was first tested among the members of the BRAPHYQS Network. Since November 2004, the test has been made available for use by all European brachytherapy centres. To date, 11 centres have participated in the checks and the results obtained are very encouraging. Nevertheless, one error detected has shown the usefulness of this audit. A method of absorbed dose to water determination in the vicinity of an (192)Ir brachytherapy source was developed for the purpose of a mailed TL dosimetry system. The accuracy of the procedure was determined. This method allows a

  11. Unfolding neutron spectra obtained from BS–TLD system using genetic algorithm

    International Nuclear Information System (INIS)

    Santos, J.A.L.; Silva, E.R.; Ferreira, T.A.E; Vilela, E.C.

    2012-01-01

    Due to the variability of neutron spectrum within the same environment, it is essential that the spectral distribution as a function of energy should be characterized. The precise information allows radiological quantities establishment related to that spectrum, but it is necessary that a spectrometric system covers a large interval of energy and an unfolding process is appropriate. This paper proposes use of a technique of Artificial Intelligence (AI) called genetic algorithm (GA), which uses bio-inspired mathematical models with the implementation of a specific matrix to unfolding data obtained from a combination of TLDs embedded in a BS system to characterize the neutron spectrum as a function of energy. The results obtained with this method were in accordance with reference spectra, thus enabling this technique to unfold neutron spectra with the BS–TLD system. - Highlights: ► The unfolding code used the artificial intelligence technique called genetic algorithms. ► A response matrix specific to the unfolding data obtained with the BS–TLD system is used by the AGLN. ► The observed results demonstrate the potential use of genetic algorithms in solving complex nuclear problems.

  12. Measurements of environmental background radiation levels by TLD in and around the Jahangirnagar University Campus

    International Nuclear Information System (INIS)

    Mollah, A.S.; Aleya Begum; Idris Miah, M.; Yunus, Afrozi

    1997-01-01

    The background radiation levels at 30 locations in and around the Jahangirnagar University Campus (JUC) were measured using a LiF(TLD-100) thermoluminescent dosimeter (TLD). In addition, dose rates at three pre-selected locations were measured on a monthly as well as quarterly basis for one year period (July 1993 - June 1994). The dose rate ranges from 1016 to 2167 μSv.y -1 (101.6 to 216.7 mrem.y -1 ) with a mean value of 1595 μSv.y -1 (159.5 mrem.y -1 ). These values are comparable with those of pre- and post-operational values for the reactor site. The estimated average annual effective dose equivalent to the inhabitants at the study areas was found to be 1276 μSv (127.6 mrem). Variation of background radiation level with meteorological parameters, namely, temperature, rainfall, relative humidity and pressure was also studied. The influence on the dose rate of the meteorological parameters was observed. (author)

  13. On the determination of the post-irradiation time from the glow curve of TLD-100

    International Nuclear Information System (INIS)

    Weinstein, M.; German, U.; Dubinsky, S.; Alfassi, Z.B.

    2003-01-01

    The ratio of peak 3 to the sum of peaks 4 + 5 in TLD-100 was measured for various pre-irradiation and post-irradiation time periods, under conditions characteristic of routine personal dosimetry. It was confirmed that the value of this ratio depends only on the elapsed time between the prior readout and the present one, independent of the moment when the irradiation took place during the total time interval (storage time). This effect indicates that fading of peak 3 seems to be due mainly to changes in the unoccupied traps, and not to decay of trapped charges, being almost independent of the presence of electrons or holes in the traps. This observation leads to the conclusion that the suggestions in the past to use the decay of peak 3 in TLD-100 for the measurement of the elapsed time between irradiation and readout may have been wrong. On the other hand, the decay of peak 2 can be used to measure the elapsed time from irradiation, since the rate of decay is different when related to pre-irradiation and post-irradiation times, indicating a much higher decay rate of the trapped charges (Randall-Wilkins decay). However, because of the fast decay rate of peak 2, its use for determination of the elapsed time since irradiation is of little practical significance. (author)

  14. The differential effects of position, ad and reader characteristics on readers' processing of newspaper ads

    NARCIS (Netherlands)

    Smit, E.G.; Neijens, P.C.; Heath, R.

    2013-01-01

    Building on previous research on the processing of newspaper ads, this comprehensive field study, with 26,556 newspaper readers and 290 unique advertisements, investigated the combined effects of position in the newspaper, ad characteristics and reader characteristics. The results show a

  15. Postdecisional counterfactual thinking by actors and readers.

    Science.gov (United States)

    Girotto, Vittorio; Ferrante, Donatella; Pighin, Stefania; Gonzalez, Michel

    2007-06-01

    How do individuals think counterfactually about the outcomes of their decisions? Most previous studies have investigated how readers think about fictional stories, rather than how actors think about events they have actually experienced. We assumed that differences in individuals' roles (actor vs. reader) can make different information available, which in turn can affect counterfactual thinking. Hence, we predicted an effect of role on postdecisional counterfactual thinking. Reporting the results of eight studies, we show that readers undo the negative outcome of a story by undoing the protagonist's choice to tackle a given problem, rather than the protagonist's unsuccessful attempt to solve it. But actors who make the same choice and experience the same negative outcome as the protagonist undo this outcome by altering features of the problem. We also show that this effect does not depend on motivational factors. These results contradict current accounts of counterfactual thinking and demonstrate the necessity of investigating the counterfactual thoughts of individuals in varied roles.

  16. Reader construction in interactive online journalism

    DEFF Research Database (Denmark)

    Hartley, Jannie Møller

    how online journalists are constructing their readers, seeking to explain how these views affect practices of journalism. Gans idea of the “constructed public” is re-visited, by analyzing the newsroom negotiations between one hand enabling the user participation and on the other hand their very...... be seen as journalistic positioning strategies and interactivity and mediated connectivity as both vital and challenging for the very field of journalism. This indicates that not only do the different kinds of interactivity seem to imply different kind of readers – they also seem to imply different ideals...

  17. Passive microfluidic array card and reader

    Science.gov (United States)

    Dugan, Lawrence Christopher [Modesto, CA; Coleman, Matthew A [Oakland, CA

    2011-08-09

    A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.

  18. Rights of Postsecondary Readers and Learners

    Science.gov (United States)

    Greenbaum, JoAnne; Angus, Kathryn Bartle

    2018-01-01

    A position statement on the rights of adult readers and learners was adopted by the CRLA board in 2002 and published with a theoretical rationale in ["Journal of College Reading and Learning"] "JCRL," Spring 2003. The statement was a guideline for educators seeking to improve the quality of adult education. In 2016, at the…

  19. Communication: Learning to Write for the Reader.

    Science.gov (United States)

    Todd, Mavis M.

    1980-01-01

    A new approach to teaching students to write effective business letters is presented. It uses class members as resources, writers, and readers for the assignment. Four stages are described: the interview, discussion of models and format, revision, and the reply. Results of the exercise and suggestions for continued application are included. (CT)

  20. Satisfying the Needs of the Serious Reader.

    Science.gov (United States)

    Hopkins, Richard

    1987-01-01

    An examination of how well the Canadian public library is meeting the needs of the serious reader interested in self education, as compared to new and secondhand book stores and academic libraries, found that the public library is the most important and effective agency in providing materials for this group. (CLB)

  1. Patterns of Analogical Reasoning among Beginning Readers

    Science.gov (United States)

    Farrington-Flint, Lee; Wood, Clare; Canobi, Katherine H.; Faulkner, Dorothy

    2004-01-01

    Despite compelling evidence that analogy skills are available to beginning readers, few studies have actually explored the possibility of identifying individual differences in young children's analogy skills in early reading. The present study examined individual differences in children's use of orthographic and phonological relations between…

  2. Collaboration between SSMJ and its readers

    African Journals Online (AJOL)

    All of us in the healthcare professions throughout the world can learn much from each other. This has been demonstrated so well by the collaboration between the editors, authors, medical experts and readers of the South Sudan Medical Journal. The Editor-in-Chief recently sent out a request for photographs and received a ...

  3. Readers' Tellings: Narrators, Settings, Flashbacks and Comprehension

    Science.gov (United States)

    Kucer, Stephen B.

    2010-01-01

    This research explores the impact of flashbacks and changes in settings and narrators on reader comprehension. Individually, 34 fourth graders (9 and 10 years of age), mostly with above average reading abilities (5.0), orally read the first chapter of a novel. Both publisher and readability formulae estimated the text to be at a fourth- grade…

  4. Towards a Culturally Situated Reader Response Theory

    Science.gov (United States)

    Brooks, Wanda; Browne, Susan

    2012-01-01

    This article describes a theory of how culture enables literary interpretations of texts. We begin with a brief overview of the reader response field. From there, we introduce the theory and provide illustrative participant data examples. These data examples illustrate the four cultural positions middle grade students in our research assumed when…

  5. Meeting the Needs of Struggling Adolescent Readers

    Science.gov (United States)

    Stover, Katie; O'Rear, Allison; Morris, Carolyn

    2015-01-01

    Research suggests that additional reading instruction is necessary to support struggling adolescent readers. In addition to time allocated for reading and access to appropriately leveled texts, many students need teacher support in learning and implementing a range of reading strategies. As a high school English teacher and a middle school Social…

  6. Shakespeare and Reader's Theatre: Fellow Traveling Companions

    Science.gov (United States)

    Ratliff, Gerald Lee

    2010-01-01

    Whether constructed on literary analysis models or inspired by conventional acting theories, Reader's Theatre performance techniques are an invaluable instructional tool available to teachers who want their students to see, hear and feel Shakespeare texts in classroom discussion and performance. These exercises are designed to promote both a…

  7. Understanding Deaf Readers: An Interpretative Phenomenological Analysis

    Science.gov (United States)

    Kelstone, Aaron Weir

    2013-01-01

    The development of reading skills, beyond a functional level, is difficult for most deaf readers. Standardized testing demonstrates a median 4th grade reading level that remains consistent even after national norming of the Stanford Achievement test on the population of deaf school children. Deaf education continues to generate various educational…

  8. The Emergent Reader's Working Kit of Stereotypes

    Science.gov (United States)

    Mackey, Margaret

    2013-01-01

    This article draws on a careful study of series fiction read in the 1950s to explore how stereotypes feature in the development of a young reader's competence in learning to process stories in print. Five categories of stereotype are teased out: "embodied stereotypes," understood through physical experience; "working stereotypes," discerned…

  9. Guiding Young Readers to Multicultural Literature

    Science.gov (United States)

    Hinton-Johnson, KaaVonia; Dickinson, Gail

    2005-01-01

    Stocking the shelves of library media centers with multicultural literature is not enough, it is important that children are helped to choose the ones that would interest them as reading about various cultures is of great benefit to young readers. The importance of accurately representing to children a multicultural society is emphasized and…

  10. Lexical Reading in Dysfluent Readers of German

    Science.gov (United States)

    Gangl, Melanie; Moll, Kristina; Jones, Manon W.; Banfi, Chiara; Schulte-Körne, Gerd; Landerl, Karin

    2018-01-01

    Dyslexia in consistent orthographies like German is characterized by dysfluent reading, which is often assumed to result from failure to build up an orthographic lexicon and overreliance on decoding. However, earlier evidence indicates effects of lexical processing at least in some German dyslexic readers. We investigated variations in reading…

  11. Readerly and Writerly "Letters from the Park."

    Science.gov (United States)

    Conde, Susana

    1993-01-01

    Discusses in depth the film "Cartas del parque" ("Letters from the Park"), the first of six films in the "Amores Dificiles" series. Notes that the film is pervaded by the traditional overdetermination of gender roles. Suggests that an intrusive and authoritative narrator makes of this both a "readerly" and a…

  12. Trade Related Reading Packets for Disabled Readers.

    Science.gov (United States)

    Davis, Beverly; Woodruff, Nancy S.

    Six trade-related reading packets for disabled readers are provided for these trades: assemblers, baking, building maintenance, data entry, interior landscaping, and warehousing. Each packet stresses from 9 to 14 skills. Those skills common to most packets include context clues, fact or opinion, details, following directions, main idea,…

  13. Response of TLD badge for the estimation of exposure conditions in diagnostic x-ray departments - use of lead aprons

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Chatterjee, S.; Bakshi, A.K.

    2002-01-01

    The present study was undertaken to ascertain the conditions of exposure of the TLD badge and to evaluate the inaccuracy involved in the estimation of dose received by the worker using an averaged lead apron transmission factor for the use of the badge above lead apron

  14. Malaysia Participation in the IAEA/ WHO TLD Postal Dose Quality Audit Service: Data Analysis From 2011-2015

    International Nuclear Information System (INIS)

    Norhayati Abdullah; Taiman Kadni

    2016-01-01

    In this paper, we report the dosimetry methodology used and the results of 22 Malaysian radiotherapy centres participated in the Thermoluminescent Dosimeter (TLD) Postal Dose Quality Audit Service organised by the International Atomic Energy Agency (IAEA) in collaboration with World Health Organisation (WHO) from 2011 to 2015. In this audit, a set of three capsules of TLD (encapsulated with Lithium Flouride powder) including a control TLD were sent to the participating centres for irradiation with 2 Gy of absorbed dose to water under reference condition. In this period, a total of 70 photon beams consists of 43 beams and 27 beams produced by 6 MV and 10 MV photon beams, respectively have been audited. The results demonstrated that all participating centres comply with the acceptance limits of ±5 % as recommended by the International Commission on Radiation Units and Measurements (ICRU) Report 24, except eight photon beams from six centres. However, these centres presented better compliance results after followed up with a second round of TLD irradiation. (author)

  15. Comprehensive automatic assessment of retinal vascular abnormalities for computer-assisted retinopathy grading.

    Science.gov (United States)

    Joshi, Vinayak; Agurto, Carla; VanNess, Richard; Nemeth, Sheila; Soliz, Peter; Barriga, Simon

    2014-01-01

    One of the most important signs of systemic disease that presents on the retina is vascular abnormalities such as in hypertensive retinopathy. Manual analysis of fundus images by human readers is qualitative and lacks in accuracy, consistency and repeatability. Present semi-automatic methods for vascular evaluation are reported to increase accuracy and reduce reader variability, but require extensive reader interaction; thus limiting the software-aided efficiency. Automation thus holds a twofold promise. First, decrease variability while increasing accuracy, and second, increasing the efficiency. In this paper we propose fully automated software as a second reader system for comprehensive assessment of retinal vasculature; which aids the readers in the quantitative characterization of vessel abnormalities in fundus images. This system provides the reader with objective measures of vascular morphology such as tortuosity, branching angles, as well as highlights of areas with abnormalities such as artery-venous nicking, copper and silver wiring, and retinal emboli; in order for the reader to make a final screening decision. To test the efficacy of our system, we evaluated the change in performance of a newly certified retinal reader when grading a set of 40 color fundus images with and without the assistance of the software. The results demonstrated an improvement in reader's performance with the software assistance, in terms of accuracy of detection of vessel abnormalities, determination of retinopathy, and reading time. This system enables the reader in making computer-assisted vasculature assessment with high accuracy and consistency, at a reduced reading time.

  16. Finding weak points automatically

    International Nuclear Information System (INIS)

    Archinger, P.; Wassenberg, M.

    1999-01-01

    Operators of nuclear power stations have to carry out material tests at selected components by regular intervalls. Therefore a full automaticated test, which achieves a clearly higher reproducibility, compared to part automaticated variations, would provide a solution. In addition the full automaticated test reduces the dose of radiation for the test person. (orig.) [de

  17. Implementation of a self-directed work team in a TLD Processing Center

    International Nuclear Information System (INIS)

    Arnwine, A.A.; Bogard, R.S.; Teasley, N.A.; Somers, D.E.; Souleyrette, M.L.

    1994-01-01

    In an effort to maintain productivity with a decreasing work force, the Oak Ridge Y-12 Plant has adopted the concept of Self-Directed Work Teams in various disciplines. The plant's Health Physics Department was able to eliminate a layer of front-line supervisors by establishing four self-directed work teams. Each team was able to choose their method of implementation. The TLD Processing Center Team chose to use project managment tools to ensure a smooth transition from the traditional work group to a self-directed approach. This process focused on establishing responsibilities, determining training requirements, determining a leadership style for the group, and performing a potential problem analysis for the transition. The transition also reviewed interface issues that could occur with upper management, matrix management, technical oversight, and organizational peers. The team's experience is also evaluated in comparison to other Self-Directed Work Teams

  18. Performance and Test Results of Harshaw Pelletised LiF:Mg,Ti TLD Material

    International Nuclear Information System (INIS)

    Velbeck, K.J.; Zhang, L.; Green, R.; Tomlins, P.

    1999-01-01

    BICRON NE has recently introduced a pelletised version of their popular TLD-100, 600 and 700 lithium fluoride based thermoluminescence dosemeters (TLDs). These materials can be used unmounted or in card and ring formats. Applications include whole-body, environmental, medical, and extremity monitoring. The former manufacturing process included purifying, growing doped LiF, grinding, blending, pressing, slicing, and dicing. The new process eliminates the last four steps, replacing them with a pelletising process. This process transforms the material directly from a powder to its final form. This new process provides the benefits of better batch uniformity and excellent dimensional consistency. The testing is described that was performed for the purpose of accepting the pelletised material as a directly interchangeable substitute for the same material produced by the former process. Tests performed include reproducibility, batch homogeneity, linearity, detection threshold, and light sensitivity. (author)

  19. A new TLD badge with machine readable ID for fully automated readout

    International Nuclear Information System (INIS)

    Kannan, S. Ratna P.; Kulkarni, M.S.

    2003-01-01

    The TLD badge currently being used for personnel monitoring of more than 40,000 radiation workers has a few drawbacks such as lack of on-badge machine readable ID code, delicate two-point clamping of dosimeters on an aluminium card with the chances of dosimeters falling off during handling or readout, projections on one side making automation of readout difficult etc. A new badge has been designed with a 8-digit identification code in the form of an array of holes and smooth exteriors to enable full automation of readout. The new badge also permits changing of dosimeters when necessary. The new design does not affect the readout time or the dosimetric characteristics. The salient features and the dosimetric characteristics are discussed. (author)

  20. Characterization of TLD-100 micro-cubes for use in small field dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Peña-Jiménez, Salvador, E-mail: zoid-9861@yahoo.com.mx; Gamboa-deBuen, Isabel, E-mail: gamboa@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510 DF (Mexico); Lárraga-Gutiérrez, José Manuel, E-mail: jose.larraga.gtz@gmail.com, E-mail: amanda.garcia.g@gmail.com; García-Garduño, Olivia Amanda, E-mail: jose.larraga.gtz@gmail.com, E-mail: amanda.garcia.g@gmail.com [Laboratorio de Física Médica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Av. Insurgentes Sur 3877, 14269 DF (Mexico)

    2014-11-07

    At present there are no international regulations for the management of millimeter scale fields and there are no suggestions for a reference detector to perform the characterization and dose determination for unconventional radiation beams (small fields) so that the dosimetry of small fields remains an open research field worldwide because these fields are used in radiotherapy treatments. Sensitivity factors and reproducibility of TLD-100 micro-cubes (1×1×1 mm3) were determinate irradiating the dosimeters with a 6 MV beam in a linear accelerator dedicated to radiosurgery at the Instituto Nacional de Neurología y Neurocirugía (INNN). Thermoluminescent response as a function of dose was determined for doses in water between 0.5 and 3 Gy and two field sizes (2×2 cm2 and 10×10 cm2). It was found that the response is linear over the dose range studied and it does not depend on field size.

  1. Evaluation of the uncertainties in the TLD radiosurgery postal dose system

    Science.gov (United States)

    Campos, L. T.; Leite, S. P.; de Almeida, C. E. V.; Magalhães, L. A. G.

    2018-03-01

    Stereotactic radiosurgery is a single-fraction radiation therapy procedure for treating intracranial lesions using a stereotactic apparatus and multiple narrow beams delivered through noncoplanar isocentric arcs. To guarantee a high quality standard, a comprehensive Quality Assurance programme is extremely important to ensure that the measured dose is consistent with the tolerance considered to improve treatment quality. The Radiological Science Laboratory operates a postal audit programme in SRT and SRS. The purpose of the programme is to verify the target localization accuracy in known geometry and the dosimetric conditions of the TPS. The programme works in such a way those thermoluminescence dosimeters, consisting of LiF chips, are sent to the centre where they are to be irradiated to a certain dose. The TLD are then returned, where they are evaluated and the absorbed dose is obtained from TLDs readings. The aim of the present work is estimate the uncertainties in the process of dose determination, using experimental data.

  2. TLD environmental monitoring at the Institute of Nuclear Engineering in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Taam, I.H. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Caixa Postal 68550, 21945-970 Rio de Janeiro, RJ (Brazil); Rosa, L.A.R. da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Av. Salvador Allende s/n, Caixa Postal 37760, 22780-160 Rio de Janeiro, RJ (Brazil)], E-mail: lrosa@ird.gov.br; Crispim, V.R. [PEN/COPPE-DNC/POLI/CT/UFRJ, Caixa Postal 68509, 21941-972 Rio de Janeiro, RJ (Brazil)

    2008-09-15

    Since 2003 the Institute of Nuclear Engineering in Rio de Janeiro city, Brazil, operates a new cyclotron, RDS-111, to produce {sup 18}F-Fluorodeoxyglucose to be used in nuclear medicine. Additionally, the IEN radioactive waste repository has been enlarged during the past last years, receiving a considerable amount of radioactive materials. Therefore, it became necessary to evaluate a possible increase of the environmental gamma exposure rates at the institute site due to the operation of the new accelerator and the enlargement of the institute waste repository as well. LiF:Mg,Cu,P, TLD-100H, and TL detectors were employed for environmental kerma rate evaluation and the results were compared with previous results obtained before the RDS-111 operation initialisation and the enlargement of IEN waste repository. No significant contribution for the enhancement of environmental gamma kerma rates was detected.

  3. Nuclear accident dosimeter designed for use with the Panasonic TLD system

    International Nuclear Information System (INIS)

    Hankins, D.E.

    1985-01-01

    A new design for the nuclear accident dosimeter (NAD) compatible with the Panasonic TLD badge has recently been adopted for use at LLNL. This NAD was tested at the 1984 Oak Ridge National Laboratory Intercomparison of Criticality Accident Dosimeters study. We describe the procedures and constants developed to evaluate the NAD components. These constants were averaged to give reasonable results from bare and moderated spectra. Other procedures to evaluate a person's neutron dose using activation of the blood sodium and hair are described. These latter procedures are used to complement the dose determined using the NAD, or to determine a dose if a NAD had not been worn during exposure. If little is known about the configuration of the fissile material or shielding between the material and the exposed person, a procedure which combines the blood and hair activations gives a good estimate of the dose. (DT) 3 refs., 2 figs., 6 tabs

  4. Effect of temperatures up to 130 deg C on the responses of TLD 700

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, J A; Binns, P J [UKAEA Atomic Energy Research Establishment, Harwell. Environmental and Medical Sciences Div.

    1984-01-01

    The need to measure doses at temperatures up to 130 deg C led to an investigation into the effect of exposure and storage at these temperatures on the response of TLD 700 before and after UV phototransfer. As a preliminary, the delays required during the UV re-estimation process were optimised. The effects of storage and exposure were compared. This was followed by a detailed examination of the effects of storage at temperatures up to 130 deg C. Glow curves were analysed to investigate the rates of growth and decay of the different peaks. The findings for peaks 6 and 7 are compatible with previously reported effects at lower temperatures on peaks 3, 4 and 5. Storage at temperatures of 130 deg C or below for periods up to 28 days does not affect the UV photo-transfer response.

  5. Radiation doses measured by TLD (thermo luminescent dosimeter) in x-ray examination

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Hiraki, Motoji; Murakami, Shozo; Nishikawa, Naozo; Yagi, Takayuki

    1977-01-01

    By means of TLD, we measured the radiation doses to the skin in the central area of the field of radiation and doses scattered outside of the radiation field, utilizing a phantom to define a suitable radiation field. Clinically, when radiography of the gall bladder and the chest was done, we measured both the radiation doses of the central skin area where radiation was done and the skin above the area of the female gonads. In radiography of the chest, the radiation doses to the skin area above the female gonads situate was under 0.1 mR. When female gonads are less than 15 cm from the margin of the radiation field of the radiation dose can be decreased by 30% if gum sheets containing lead are used to cover the skin area outside the radiation field. (auth.)

  6. A review of TLD's zero-count based on temperature and radiation history of them

    Science.gov (United States)

    Tunçel, Nina; Karakuş, İsmail; Dündar, Ertuğrul; Toykan Çiflikçi, Özlem

    2017-09-01

    In order to review the background value of a group of TLD-100, the zero-count values were collected from the first reading and after seven years after using them in experimental irradiations. The zero-counts for these two conditions were collected, as well as the dependence of temperature and radiation history of this group was evaluated. This study recommended that after frequently irradiation of TLDs the rearrangement for obtaining zero-count value must be performed before using TLDs in a new irradiation examination. Regarding on memory of radiation and thermal history, the sensitivity can change after receiving a large dose of radiation and undergoing readout. Additional annealing would be necessary to restore the original sensitivity. TLDs must be used under reproducible conditions to obtain consistent results.

  7. The cardiac catheterization laboratory personnel TLD dosimetry in Dr. Faghihi Hospital in Shiraz

    International Nuclear Information System (INIS)

    Derakhshan, Sh.

    2004-01-01

    In this study all of the personnel of Angiography of Dr.Faghihi hospital used TLD service During 2002-2003. This service was given by center for Radiation Protection and Application of the Shiraz University. These staff were divided in two group, one groups was technicians and the other group was the nurses. The result of this research shows that the maximum dose received to Technicians and nurses were 0.4mSv and 0.55mSV respectively. The average annual dose to technicians and nurses were 0.02 mSv and 0.19 mSv. This result shows that the nurses of this hospital receive more dose than the techniques

  8. Response of TLD-100 LiF dosimeters for X-rays of low energies

    International Nuclear Information System (INIS)

    Bonzi, E. V.; Mainardi, R. T.

    2011-10-01

    In diverse practical applications as the existent in radiological clinics, industrial facilities and research laboratories, the solid state dosimeters are used for the measure of the different types of ionizing radiations. At the present time dosimeters are manufactured with different types of materials that present thermoluminescent properties, to the effects of determining the absorbed radiation dose. Under these conditions, the radiation dose is determined integrated in all the range of energies of the beam of X-rays, since it assumes that the response of these dosimeters is lineal with the energy of the photons or radiant particles. Because interest exists in advancing in the development of a determination method in the way of the X-rays spectrum emitted by a tube of those used in diagnostic or therapy, we have measured the response of TLD-100 LiF dosimeters for low energies, minor at 60 keV, for a several group of these dosimeters. (Author)

  9. Thermoluminescence of pure LiF and Lif (TLD-100) irradiated at room temperature

    International Nuclear Information System (INIS)

    Sagastibelza Chivite, F.

    1980-01-01

    The thermoluminescence of pure LiF and LiF (TLD-100) crystals irradiated at room temperature with x - or gamma-rays has been studied up to 460 degree centigree. For most of the glow peaks found the kinetics, preexponential factors and activation energies have been determined. These parameters have been obtained by means of the isothermal method. The study of the thermal annealing of the radiation induced F and Z centres has allow to show that there is a correlation among the glow peaks and the annealing stages of these centres. It is concluded that the F and Z - centres play the role of recombination centres for halogen interstitial atom thermally released from traps. Light emission occurs in this recombination. (Author) 120 refs

  10. Evaluation of the kinetic parameters of CaF2:Tm (TLD-300) thermoluminescence dosemeters

    International Nuclear Information System (INIS)

    Azorin, Juan; Gutierrez, Alicia; Furetta, Claudio

    1989-01-01

    The kinetic parameters of the first, third and fifth peaks of CaF 2 :Tm (TLD-300) dosemeters were determined experimentally using methods based on initial rise, peak shape, different heating rates, isothermal decay and numerical fitting method and a comparison was made between the results obtained. The average activation energy values determined by the methods used here were 0.72, 1.16 and 1.77 eV, with mean values for the frequency factor of 2.58 x 10 8 , 2.89 x 10 13 and 6.16 x 10 16 s -1 for the first, third and fifth peaks respectively. The values of activation energy obtained for each peak using the different methods covered a spread of about 4%. However, the spread for each of the frequency factors was very high. (author)

  11. Unfolding neutron spectra with BS-TLD system using genetic algorithms

    International Nuclear Information System (INIS)

    Santos, Joelan A.L.; Silva, Everton R.; Vilela, Eudice C.

    2011-01-01

    Due to the variability of neutron spectrum within the same environment, it is essential that the spectral distribution as function of energy to be characterized. To perform this task, the neutron spectrometer has a primary role in determining the neutron flux (Φ E (E)). Precise information allows radiological quantities establishment related to that spectrum but it is necessary, however, a series of steps with a spectrometric system that can cover a large interval of energy and whose answer is isotropic. The most widely used for accomplishing this task is the spectrometric Bonner spheres system. One of the biggest problems related to neutron spectrometry is the process of data analysis, known as unfolding. Most of the work undertaken to implement new techniques of this process, using data obtained with the scintillator 6 LiI(I). However, characteristics related to the dead time make it not be so effective when used in high flow neutron fields. An alternative to this problem is the use of thermoluminescent detectors (TLD), but the codes used do not provide a more specific response matrix to unfolding the information obtained through these materials, which makes the development of a specific response matrix important to adequately characterize the response obtained by them. This paper proposes using a technique of artificial intelligence called genetic algorithm, which uses bio-inspired mathematical models and through the implementation of a specific matrix to unfolding data obtained from a combination of TLDs embedded in a system of Bonner spheres, such as thermal neutron detectors, to characterize the neutron spectrum as a function of energy. The results obtained with this method were in accordance with reference spectra, thus enables of this technique to unfolding neutrons spectra with BS-TLD system. (author)

  12. Unfolding neutron spectra with BS-TLD system using genetic algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joelan A.L., E-mail: jasantos@cnen.gov.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Silva, Everton R. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Informatica; Ferreira, Tiago A.E. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Estatistica e Informatica; Fonseca, Evaldo S. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Vilela, Eudice C., E-mail: ecvilela@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    Due to the variability of neutron spectrum within the same environment, it is essential that the spectral distribution as function of energy to be characterized. To perform this task, the neutron spectrometer has a primary role in determining the neutron flux ({Phi}{sub E}(E)). Precise information allows radiological quantities establishment related to that spectrum but it is necessary, however, a series of steps with a spectrometric system that can cover a large interval of energy and whose answer is isotropic. The most widely used for accomplishing this task is the spectrometric Bonner spheres system. One of the biggest problems related to neutron spectrometry is the process of data analysis, known as unfolding. Most of the work undertaken to implement new techniques of this process, using data obtained with the scintillator {sup 6}LiI(I). However, characteristics related to the dead time make it not be so effective when used in high flow neutron fields. An alternative to this problem is the use of thermoluminescent detectors (TLD), but the codes used do not provide a more specific response matrix to unfolding the information obtained through these materials, which makes the development of a specific response matrix important to adequately characterize the response obtained by them. This paper proposes using a technique of artificial intelligence called genetic algorithm, which uses bio-inspired mathematical models and through the implementation of a specific matrix to unfolding data obtained from a combination of TLDs embedded in a system of Bonner spheres, such as thermal neutron detectors, to characterize the neutron spectrum as a function of energy. The results obtained with this method were in accordance with reference spectra, thus enables of this technique to unfolding neutrons spectra with BS-TLD system. (author)

  13. A TLD-based personal dosemeter system for air crew monitoring

    International Nuclear Information System (INIS)

    Hajek, M.; Berger, T.; Vana, N.

    2003-01-01

    Full text: Due to the complex spectrum of different particles and energies involved, in-flight radiation dosimetry is usually associated with extensive instrumentation. The exposure of air crew personnel to cosmic radiation is paid serious attention, being further enhanced by the release of the European Council Directive 96/29/Euratom which makes the surveillance of crew members an obligatory issue. The high temperature ratio (HTR) method for small and easy-to-handle LiF:Mg,Ti thermoluminescent dosimeters was developed at the Atomic Institute of the Austrian Universities and fulfils these demands by permitting the determination of dose equivalent in radiation fields of unknown composition. The method uses the relative intensity of glow peaks 6 and 7 compared with the dominant peak 5 in the LiF Tl emission as an indication for the average LET and, thus, the mean quality factor of the radiation field. Extensive experiments in various ion beams established a HTR vs. LET calibration curve for the commercially available Tl phosphors TLD-600 and TLD-700. Additionally, the different neutron sensitivity of both types may be exploited for the determination of the dose equivalent delivered from neutrons which dominate at aviation altitudes. However, it is essential that the calibration of the Tl detectors is performed in a neutron environment of similar spectral shape as that encountered in flight. In our case, this constraint was satisfied by the CERN-EU High-Energy Reference Field (CERF). Results of both neutron and total dose equivalent for several different north-bound and trans-equatorial routes are presented, ranging from 2.1 ± 0.1 μSv/h with a 30 % neutron contribution for Vienna-Sydney to 4.9 ± 0.2 μSv/h and a roughly 55 % neutron contribution for Vienna-Tokyo. The measured route doses are compared with CARI-6M calculations. (author)

  14. The IAEA/WHO TLD postal dose quality audits for radiotherapy: a perspective of dosimetry practices at hospitals in developing countries

    International Nuclear Information System (INIS)

    Izewska, Joanna; Andreo, Pedro; Vatnitsky, Stanislav; Shortt, Ken R.

    2003-01-01

    Background and purpose: The IAEA/WHO TLD postal programme for external audits of the calibration of high-energy photon beams used in radiotherapy has been in operation since 1969. This work presents a survey of the 1317 TLD audits carried out during 1998-2001. The TLD results are discussed from the perspective of the dosimetry practices in hospitals in developing countries, based on the information provided by the participants in their TLD data sheets. Materials and methods: A detailed analysis of the TLD data sheets is systematically performed at the IAEA. It helps to trace the source of any discrepancy between the TLD measured dose and the user stated dose, and also provides information on equipment, dosimetry procedures and the use of codes of practice in the countries participating in the IAEA/WHO TLD audits. Result: The TLD results are within the 5% acceptance limit for 84% of the participants. The results for accelerator beams are typically better than for Co-60 units. Approximately 75% of participants reported dosimetry data, including details on their procedure for dose determination from ionisation chamber measurements. For the remaining 25% of hospitals, who did not submit these data, the results are poorer than the global TLD results. Most hospitals have Farmer type ionisation chambers calibrated in terms of air kerma by a standards laboratory. Less than 10% of the hospitals use new codes of practice based on standards of absorbed dose to water. Conclusion: Despite the differences in dosimetry equipment, traceability to different standards laboratories and uncertainties arising from the use of various dosimetry codes of practice, the determination of absorbed dose to water for photon beams typically agrees within 2% among hospitals. Correct implementation of any of the dosimetry protocols should ensure that significant errors in dosimetry are avoided

  15. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia; Dosimetria personal TLD 110 en medicos ortopedistas expuestos a radiacion ionizante en Bogota - Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Sierra C, B. Y.; Jimenez, Y. [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Fisica Medica, Carrera 45 No. 26-85, Bogota (Colombia); Plazas, M. C. [Hospital Universitario Fundacion Santa Fe de Bogota, Instituto de Oncologia Carlos Ardila Lulle, Calle 119, No. 7-90, 220246 Bogota (Colombia); Eslava S, J. [Universidad Nacional de Colombia, Instituto de Investigaciones Clinicas, Grupo Equidad en Salud, Carrera 45 No. 26-85, Bogota (Colombia); Groot R, H., E-mail: brigith.sierra@gmail.com [Universidad de los Andes, Laboratorio de Genetica Humana, Carrera 1 No. 18A -12, Bogota (Colombia)

    2014-08-15

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  16. Traceability of a panoramic gamma irradiator using different TLD systems as transfer Instruments; Trazabilidad de un irradiador panoramico mediante sistemas de dosimetria TL

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A. M.; Saez, J. C

    1994-07-01

    This work shows the calibration in terms of the new operational radiological quantities Hp (10) and H(10) for different TLD systems (Harshaw TLD-100 and Panasonic UD-002) used in personal and environmental monitoring. The irradiations were performed in the Spanish Reference Laboratory in radiation protection levels, managed by the CIEMAT Metrology of ionizing radiations Unit. With those data, different calibrations of a panoramic gamma irradiator in terms of the radiological quantity for unit of time were established, providing the traceability of the irradiator to the Reference Laboratory using the corresponding TLD systems as transfer instruments. (Author) 9 refs.

  17. Traceability of a panoramic gamma irradiator using different TLD systems as transfer instruments; Trazabilidad de un irradiador panoramico mediante sistemas de dosimetria TL

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.M.; Saez, J.C.

    1994-08-01

    This work shows the calibration in terms of the new operational radiological quantities Hp(10) and H*(10) for different TLD systems (Harshaw TLD-100 and Panasonic UD-802) used in personal and environmental monitoring. The irradiations were performed in the Spanish Reference Laboratory in radiation protection levels, managed by the CIEMAT Metrology of ionizing radiations Unit. With these data, different calibrations of a panoramic gamma irradiator in terms of the radiological quantity for unit of time were established, providing the traceability of the irradiator to the Reference Laboratory using the corresponding TLD systems as transfer instruments. (Author) 9 refs.

  18. Blind Braille readers mislocate tactile stimuli.

    Science.gov (United States)

    Sterr, Annette; Green, Lisa; Elbert, Thomas

    2003-05-01

    In a previous experiment, we observed that blind Braille readers produce errors when asked to identify on which finger of one hand a light tactile stimulus had occurred. With the present study, we aimed to specify the characteristics of this perceptual error in blind and sighted participants. The experiment confirmed that blind Braille readers mislocalised tactile stimuli more often than sighted controls, and that the localisation errors occurred significantly more often at the right reading hand than at the non-reading hand. Most importantly, we discovered that the reading fingers showed the smallest error frequency, but the highest rate of stimulus attribution. The dissociation of perceiving and locating tactile stimuli in the blind suggests altered tactile information processing. Neuroplasticity, changes in tactile attention mechanisms as well as the idea that blind persons may employ different strategies for tactile exploration and object localisation are discussed as possible explanations for the results obtained.

  19. The automated Risoe TL dating reader system

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.

    1988-01-01

    The features of the new modified Riso TL dating reader system are described. A vacuum chamber that accommodates the entire 24-position sample changer unit has been designed. The vacuum and N 2 -gas functions are software-controlled. A newly designed heater system is capable of repeated heating cycles to 700 0 C. The sample changer system accommodates fine-grain discs as well as planchettes for coarse grains. Two software-controlled beta irradiators can be attached to the reader, e.g. for predose measurement. The software allows a user without programming expertise to create any desired measuring sequence, and to store and recall data and glow curves for making analyses. (author)

  20. Mathematics skills in good readers with hydrocephalus.

    Science.gov (United States)

    Barnes, Marcia A; Pengelly, Sarah; Dennis, Maureen; Wilkinson, Margaret; Rogers, Tracey; Faulkner, Heather

    2002-01-01

    Children with hydrocephalus have poor math skills. We investigated the nature of their arithmetic computation errors by comparing written subtraction errors in good readers with hydrocephalus, typically developing good readers of the same age, and younger children matched for math level to the children with hydrocephalus. Children with hydrocephalus made more procedural errors (although not more fact retrieval or visual-spatial errors) than age-matched controls; they made the same number of procedural errors as younger, math-level matched children. We also investigated a broad range of math abilities, and found that children with hydrocephalus performed more poorly than age-matched controls on tests of geometry and applied math skills such as estimation and problem solving. Computation deficits in children with hydrocephalus reflect delayed development of procedural knowledge. Problems in specific math domains such as geometry and applied math, were associated with deficits in constituent cognitive skills such as visual spatial competence, memory, and general knowledge.

  1. Plastic Logic quits e-reader market

    Science.gov (United States)

    Perks, Simon

    2012-07-01

    A UK firm spun out from the University of Cambridge that sought to be a world leader in flexible organic electronic circuits and displays has pulled out of the competitive e-reader market as it struggles to find a commercial outlet for its technology. Plastic Logic announced in May that it is to close its development facility in Mountain View, California, with the loss of around 40 jobs.

  2. Movie reviews: Who are the readers?

    OpenAIRE

    Jose Ignacio Azuela Flores; Victor Fernandez-Blanco; Maria Jose Sanzo-Perez

    2012-01-01

    The analysis of the relationship between movie reviews and consumer's decision process has focused mainly on the side of critics, who have been defined as "influencers" or as "predictors" (Eliashberg & Shugan, 1997). Also, new ways to measure the impact of the critic have been introduced (Gemser, van Oostrum & Leenders, 2007) and the consistency of their opinions over time has been proved (Ginsburgh & Weyers, 1999). However, there is scarce evidence about the readers of movie reviews: who are...

  3. Tactile spatial resolution in blind braille readers.

    Science.gov (United States)

    Van Boven, R W; Hamilton, R H; Kauffman, T; Keenan, J P; Pascual-Leone, A

    2000-06-27

    To determine if blind people have heightened tactile spatial acuity. Recently, studies using magnetic source imaging and somatosensory evoked potentials have shown that the cortical representation of the reading fingers of blind Braille readers is expanded compared to that of fingers of sighted subjects. Furthermore, the visual cortex is activated during certain tactile tasks in blind subjects but not sighted subjects. The authors hypothesized that the expanded cortical representation of fingers used in Braille reading may reflect an enhanced fidelity in the neural transmission of spatial details of a stimulus. If so, the quantitative limit of spatial acuity would be superior in blind people. The authors employed a grating orientation discrimination task in which threshold performance is accounted for by the spatial resolution limits of the neural image evoked by a stimulus. The authors quantified the psychophysical limits of spatial acuity at the middle and index fingers of 15 blind Braille readers and 15 sighted control subjects. The mean grating orientation threshold was significantly (p = 0.03) lower in the blind group (1.04 mm) compared to the sighted group (1.46 mm). The self-reported dominant reading finger in blind subjects had a mean grating orientation threshold of 0.80 mm, which was significantly better than other fingers tested. Thresholds at non-Braille reading fingers in blind subjects averaged 1.12 mm, which were also superior to sighted subjects' performances. Superior tactile spatial acuity in blind Braille readers may represent an adaptive, behavioral correlate of cortical plasticity.

  4. A portable eBook reader for the blind.

    Science.gov (United States)

    Velazquez, Ramiro; Hernandez, Hermes; Preza, Enrique

    2010-01-01

    This paper presents the design and first prototype of the TactoBook system, a novel concept of reading assistive device that aims to make eBooks accessible to the blind. The TactoBook consists of a computer-based software translator that converts fast and automatically any eBook into Braille. The Braille version of the eBook is then encrypted as a file and stored in a USB memory drive which is later inserted and reproduced in a compact, lightweight, and highly-portable tactile terminal. Braille readers can store multiple eBooks in the same USB and access/reproduce them in the tactile terminal without this being plugged to a computer. The first Braille terminal developed is a 10-cell prototype based on a piezoelectric ultrasonic actuation approach. Its overall performance is quite similar to the one obtained with traditional Braille terminals. However, unlike them, the full device is only 1 kg mass and its compact dimensions (20 × 15 × 10 cm) make it easily carried by the user. A technical overview of all subsystems is presented and discussed.

  5. Automatic and creative skills in reading Automatic and creative skills in reading

    Directory of Open Access Journals (Sweden)

    Leonor Scliar Cabral

    2008-04-01

    Full Text Available In this article I will discuss the automatic and creative skills in reading, focusing on the differences between 1 processes involved while learning how to read and processes employed by the proficient reader and 2 knowledge for using language and metalinguistic awareness. The arguments will derive mainly from the definition of reading as a process where the receivers combine the information extracted from the written material with their specialized knowledge activated during this process (i.e. linguistic systems and correspondent rules and enciclopedic knowledge in order to comprehend, interpret and internalize structured new information and/or to experience aesthetic pleasure. Evidence to illustrate the arguments comes from experiments (1 with pre-school children and beginning readers on narrativity and on the dichotic paradigm, and with illiterate and literate adults with diferent levels of proficiency of reading in a task of erasing an initial syllable and an initial consonant. In this article I will discuss the automatic and creative skills in reading, focusing on the differences between 1 processes involved while learning how to read and processes employed by the proficient reader and 2 knowledge for using language and metalinguistic awareness. The arguments will derive mainly from the definition of reading as a process where the receivers combine the information extracted from the written material with their specialized knowledge activated during this process (i.e. linguistic systems and correspondent rules and enciclopedic knowledge in order to comprehend, interpret and internalize structured new information and/or to experience aesthetic pleasure. Evidence to illustrate the arguments comes from experiments (1 with pre-school children and beginning readers on narrativity and on the dichotic paradigm, and with illiterate and literate adults with diferent levels of proficiency of reading in a task of erasing an initial syllable

  6. Automatic Photoelectric Telescope Service

    International Nuclear Information System (INIS)

    Genet, R.M.; Boyd, L.J.; Kissell, K.E.; Crawford, D.L.; Hall, D.S.; BDM Corp., McLean, VA; Kitt Peak National Observatory, Tucson, AZ; Dyer Observatory, Nashville, TN)

    1987-01-01

    Automatic observatories have the potential of gathering sizable amounts of high-quality astronomical data at low cost. The Automatic Photoelectric Telescope Service (APT Service) has realized this potential and is routinely making photometric observations of a large number of variable stars. However, without observers to provide on-site monitoring, it was necessary to incorporate special quality checks into the operation of the APT Service at its multiple automatic telescope installation on Mount Hopkins. 18 references

  7. Automatic Fiscal Stabilizers

    Directory of Open Access Journals (Sweden)

    Narcis Eduard Mitu

    2013-11-01

    Full Text Available Policies or institutions (built into an economic system that automatically tend to dampen economic cycle fluctuations in income, employment, etc., without direct government intervention. For example, in boom times, progressive income tax automatically reduces money supply as incomes and spendings rise. Similarly, in recessionary times, payment of unemployment benefits injects more money in the system and stimulates demand. Also called automatic stabilizers or built-in stabilizers.

  8. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of high temperature peaks in TLD-100 dosemeters; Eficiencias termoluminiscentes relativas proton/gamma y helio/gamma de picos de alta temperatura en dosimetros TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Flores M, E.; Avila, O.; Rodriguez V, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Massillon, J.L.G.; Buenfil A, E.; Ruiz T, C.; Brandan, M.E. [IFUNAM, 04500 Mexico D.F. (Mexico); Gamboa De Buen, I. [ICN-UNAM, 04500 Mexico D.F. (Mexico)

    2007-07-01

    This work presents measures of relative thermoluminescent efficiency of those high temperature peaks of TLD-100 dosemeters exposed to protons of 1.5 MeV and to helium nuclei of 3 and 7.5 MeV. A rigorous reading and of deconvolution protocol was used for the calculation of the TL efficiencies. Additionally an Excel program that facilitated the deconvolution adjustment process of the glow curves was elaborated. (Author)

  9. 21 CFR 886.5800 - Ophthalmic bar reader.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic bar reader. 886.5800 Section 886.5800...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5800 Ophthalmic bar reader. (a) Identification. An ophthalmic bar reader is a device that consists of a magnifying lens intended for use by a...

  10. Readers and Texts in the Primary Years. Rethinking Reading.

    Science.gov (United States)

    Martin, Tony; Leather, Bob

    Exploring the responses of a variety of readers from three-year-old Dominic sharing a picture book with his father to adults reading a poem by Ted Hughes, this book examines the ways in which various readers respond to different texts. The aim of the book is to develop an awareness of the issues involved in readers' responses for primary teachers.…

  11. Rereading Multicultural Readers: What Definition of Multicultural Are We Buying?

    Science.gov (United States)

    Shapiro, Nancy

    A flood of new multicultural readers and textbooks are hitting the market for writing and literature courses at the college level. Yet there has been no systematic examination of how these readers are being used, the purposes and audiences for which they are written, or the critical reception they have received. Multicultural readers distinguish…

  12. Choosing the Adequate Level of Graded Readers--Preliminary Study

    Science.gov (United States)

    Prtljaga, Jelena; Palinkaševic, Radmila; Brkic, Jovana

    2015-01-01

    Graded readers have been used as second language teaching material since the end of the Second World War. They are an important source of simplified material which provides comprehensible input on all levels. It is of crucial importance for a successful usage of graded readers in the classroom and in studies which focus on graded readers, that an…

  13. Gifted Male Readers: Current Understandings and Suggestions for Future Research

    Science.gov (United States)

    Pagnani, Alexander R.

    2013-01-01

    Research literature concerning gifted male readers relies primarily on more extensive bodies of work regarding gifted males and male readers. Studied as a whole, the two halves portray a worrisome state of affairs for gifted male readers, who lag behind their female counterparts in the same patterns found across the ability spectrum. This literacy…

  14. Reader Engagement in English and Persian Applied Linguistics Articles

    Science.gov (United States)

    Ansarin, Ali Akbar; Tarlani-Aliabdi, Hassan

    2011-01-01

    There is an increasing interest in the way academic writers establish the presence of their readers over the past few years. Establishing the presence of readers or what Kroll (1984, p.181) calls imagining "a second voice" is accomplished when a writer refers "explicitly" to their readers using explicit linguistic resources…

  15. Reading and Spelling Error Analysis of Native Arabic Dyslexic Readers

    Science.gov (United States)

    Abu-rabia, Salim; Taha, Haitham

    2004-01-01

    This study was an investigation of reading and spelling errors of dyslexic Arabic readers ("n"=20) compared with two groups of normal readers: a young readers group, matched with the dyslexics by reading level ("n"=20) and an age-matched group ("n"=20). They were tested on reading and spelling of texts, isolated…

  16. Comparison between indicators dosimetric released by teams and estimates by dosimetry TLD in the mammography of the Hospital Universitario 12 de Octubre

    International Nuclear Information System (INIS)

    Rot San Juan, M. J.; Martinez Gomez, L. C.; Gilarranz Moreno, R.; Milanes Gaillet, A. I.; Adaimi Hernandez, P.; Delgado rodriguez, J. M.

    2013-01-01

    With the incorporation of new technology, computers have indicators of dose for this magnitude. In this work we will compare to the mammography in our area the measure with the DSE TLD values thrown by the equipment. (Author)

  17. Logic for computer science foundations of automatic theorem proving

    CERN Document Server

    Gallier, Jean H

    2015-01-01

    This advanced text for undergraduate and graduate students introduces mathematical logic with an emphasis on proof theory and procedures for algorithmic construction of formal proofs. The self-contained treatment is also useful for computer scientists and mathematically inclined readers interested in the formalization of proofs and basics of automatic theorem proving. Topics include propositional logic and its resolution, first-order logic, Gentzen's cut elimination theorem and applications, and Gentzen's sharpened Hauptsatz and Herbrand's theorem. Additional subjects include resolution in fir

  18. Automatic differentiation bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, G.F. [comp.

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  19. TLD-100 glow-curve deconvolution for the evaluation of the thermal stress and radiation damage effects

    CERN Document Server

    Sabini, M G; Cuttone, G; Guasti, A; Mazzocchi, S; Raffaele, L

    2002-01-01

    In this work, the dose response of TLD-100 dosimeters has been studied in a 62 MeV clinical proton beams. The signal versus dose curve has been compared with the one measured in a sup 6 sup 0 Co beam. Different experiments have been performed in order to observe the thermal stress and the radiation damage effects on the detector sensitivity. A LET dependence of the TL response has been observed. In order to get a physical interpretation of these effects, a computerised glow-curve deconvolution has been employed. The results of all the performed experiments and deconvolutions are extensively reported, and the TLD-100 possible fields of application in the clinical proton dosimetry are discussed.

  20. An approach to an analysis of the energy response of LiF-TLD to high energy electrons

    International Nuclear Information System (INIS)

    Shiragai, A.

    1977-01-01

    Responses of LiF-TLD to high energy electrons relative to 60 Co γ-rays were investigated experimentally and theoretically. The Burlin et al. theory (Burlin, T.E., Snelling, R.J., and Owen, B., 1969, in Proc.2nd Symp. on Microdosimetry, Stresa, Italy; Brussels: Commission of European Communities; p.455), its modified version by Almond and McCray (Almond, P.R., and McCray, K., 1970, Phys.Med.Biol., vol.15, 335 and 746) and the Holt et al. semi-empirical theory (Holt, J.G., Edelstein, G.R., and Clark, T.E., 1975, Phys.Med.Biol., vol.20, 559) were examined in comparison with each experiment. An approximate approach to theoretical analysis of energy response of LiF-TLD was attempted and compared with some experimental results. (author)

  1. Personnel photon dosimeter on the base of TLD sup n sup a sup t LiF

    CERN Document Server

    Kaskanov, G Y

    2003-01-01

    A personnel photon dosemeter on the basis of thermoluminescence detectors (TLD) sup n sup a sup t LiF is described. Experimental responses of the dosemeters in the unit of individual equivalent dose H sub p (10) for energy of photons 59.5, 120, 662, and 1250 keV are presented. It is shown that the dosemeter allows one to measure H sub p (10) with admissible uncertainty in the energy range from 60 to 1250 keV.

  2. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of high temperature peaks in TLD-100 dosemeters

    International Nuclear Information System (INIS)

    Flores M, E.; Avila, O.; Rodriguez V, M.; Massillon, J.L.G.; Buenfil A, E.; Ruiz T, C.; Brandan, M.E.; Gamboa De Buen, I.

    2007-01-01

    This work presents measures of relative thermoluminescent efficiency of those high temperature peaks of TLD-100 dosemeters exposed to protons of 1.5 MeV and to helium nuclei of 3 and 7.5 MeV. A rigorous reading and of deconvolution protocol was used for the calculation of the TL efficiencies. Additionally an Excel program that facilitated the deconvolution adjustment process of the glow curves was elaborated. (Author)

  3. Techno-Literacy Practices of Emergent Readers

    Directory of Open Access Journals (Sweden)

    Razeale G. Fernandez

    2015-12-01

    Full Text Available – This research explored the techno-literacy practices of emergent readers. The study found that young children experienced a multi-literate practices in their homes that comprised not only print and paper-based literacies but also techno-literacies. That television, games on tablets and phones are the sources of textual pleasure of young children.Families reported that children watched television and play games on tablets/phones regularly. This is due to the limited options of leisure activities available to younger children. Emergent readers are highly focused to televisual text as they demonstrate meaningmaking practices when they constantly ask questions and talk about what they are watching,hence they are active meaning-makers. The learning opportunities which include hand eye coordination, parallel processing, and problem solving skills young children acquired through playing computer games and games on tablet/iPad . Aside from these, they also developed a number of literacy skills as well as how to behave as players.It can be concluded thatexposure to imagery in electronic technologies contributed to the children’s literacy development. The literate identities of emergent readers can be further enhanced as they begin formal schooling. Data indicated that young children are developing techno-literacy practices and this concurs to the findings of Marsh (2010. Therefore, technology serves as a tool for the literacy development of young children. That techno-literacy practices of young children should be valued in school. Future research should also consider attitude, behavior and practices of parents towards the use of technology by children.

  4. Face-to-face with the reader

    Directory of Open Access Journals (Sweden)

    Thomas SCHMITZ

    2016-03-01

    Full Text Available From the scientific perspective this review is very interesting. It is well-structured, has an attractive lay-out and typography and serves as an important forum for the scientific debate on public administration in the Republic of Moldova. Furthermore, there is a special website with several subwebsites for the review. This makes it easy for every interested reader to get an idea of the review. Finally, the websites allows free downloads even of the newest issue. This allows everybody to read it, even students (because it is free and foreign researchers (who otherwise would not have access to Moldovan scientific reviews.

  5. BOOK REVIEW: Astrophysics (Advanced Physics Readers)

    Science.gov (United States)

    Kibble, Bob

    2000-07-01

    Here is a handy and attractive reader to support students on post-16 courses. It covers the astrophysics, astronomy and cosmology that are demanded at A-level and offers anyone interested in these fields an interesting and engaging reference book. The author and the production team deserve credit for producing such an attractive book. The content, in ten chapters, covers what one would expect at this level but it is how it is presented that struck me as the book's most powerful asset. Each chapter ends with a summary of key ideas. Line drawings are clear and convey enough information to make them more than illustrations - they are as valuable as the text in conveying information. Full colour is used throughout to enhance illustrations and tables and to lift key sections of the text. A number of colour photographs complement the material and serve to maintain interest and remind readers that astrophysics is about real observable phenomena. Included towards the end is a set of tables offering information on physical and astronomical data, mathematical techniques and constellation names and abbreviations. This last table puzzled me as to its value. There is a helpful bibliography which includes society contacts and a website related to the text. Perhaps my one regret is that there is no section where students are encouraged to actually do some real astronomy. Astrophysics is in danger of becoming an armchair and calculator interest. There are practical projects that students could undertake either for school assessment or for personal interest. Simple astrophotography to capture star trails, observe star colours and estimate apparent magnitudes is an example, as is a simple double-star search. There are dozens more. However, the author's style is friendly and collaborative. He befriends the reader as they journey together through the ideas. There are progress questions at the end of each chapter. Their style tends to be rather closed and they emphasize factual recall

  6. Study of the influence of the time temperature profile on the minimum detectable dose of TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Leonardo S.; Lacerda, Marco Aurelio S.; Meira-Belo, Luiz C.; Ferreira, Hudson R., E-mail: meirelesls@cdtn.br, E-mail: masl@cdtn.br, E-mail: lcmb@cdtn.br, E-mail: hrf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Monitoring of workers and workplaces is an integral part of any radiation protection programme (RPP). It is essential to demonstrate compliance with regulations that limit the allowable dose to the public from manmade sources and to enable the responsible of the installations to verify compliance with the legal dose limits to the workers and ALARA goals. Thermoluminescent dosemeters (TLDs) are generally employed to assess the environmental and personnel doses. To completely characterize a TLD dosimetry system is fundamental to determine the Lowest Dose that the system is capable of measuring. As the amount of the light emitted by TLD material is a function of the time temperature profile (TTP), in the present study, the influence of the TTP on the Detection Threshold (MDD) of the LiF:Mg,Ti (TLD-100) detectors was evaluated. Eighteen different TTPs were tested for two different annealing processes: (I) utilization of the TTP itself and; (II) a microprocessor controlled oven annealing procedure. Results showed that TTP choice can influence significantly in the MDD values. The worst results were generally found for TLDs annealed by the TTP itself. The lack of pattern or the unexpected behavior to the influence of some parameters of the TTP on the calculated MDDs must be carefully investigated. Greater variations on the TTP parameters must be undertaken. Special attention must be also done on the methodology of calculating the MDDs. (author)

  7. Test of an albedo neutron dosimetry system: TLD calibration and readout procedure, neutron calibration, dosimetry properties, routine application

    International Nuclear Information System (INIS)

    Piesch, E.; Burgkhardt, B.

    1988-03-01

    The two-component albedo dosemeter in use consists of an universal boron-loaded plastic encapsulation, the beta and albedo neutron windows of which are adopted to the corresponding TLD system of the manufacturers Alnor, Harshaw, Panasonic and Vinten. Beside the TLD detectors the capsule may contain also track etch detectors. Within a BMU project the system was investigated by four governmental measurement services in the FRG with respect to its qualification for personnel monitoring with emphasis in the readout and calibration procedures for the TLD system, the evaluation technique for the estimation of the photon and neutron dose equivalent in routine monitoring and the calibration of the personnel dosemeter in stray neutron fields. The test has shown the readiness of the system to act in the application areas of nuclear power reactors and linacs behind heavy shieldings, in the fuel element cycle, use of fissile materials, criticality, use of radionuclide sources, high energy particle accelerators. The uncertainty due to energy dependence was found to be within a factor of 2 for a single application area. In the case of irradiations from the front half space the dose equivalent H'(10) is indicated sufficiently independent of the direction of the radiation incidence. After completion of the test the albedo dosemeter became the official neutron personnel dosemeter in the FRG. It allows the separate estimation of the dose equivalent of hard beta radiation, photon radiation and neutrons. (orig./HP) [de

  8. A Pb-TLD spectrometer to measure high energy photons in z-pinch experiments on the primary test stand

    International Nuclear Information System (INIS)

    Si, Fenni; Yang, Jianlun; Xu, Rongkun; Yuan, Xi; Huang, Zhanchang; Ye, Fan; Wang, Dong; Zhang, Chuanfei

    2017-01-01

    Highlights: • A Pb-TLD spectrometer has been developed to measure spectra of high energy photons in wire-array z pinches on PTS. • Energy spectra of high energy photons on PTS has been firstly obtained by unfolding programs developed with MATLAB code. • The energy of high energy x-ray on PTS is obtained to be mainly within the region of 100 keV to 1.3 MeV. - Abstract: A Pb-TLD spectrometer has been developed based on attenuation techniques to measure high energy photons in wire-array z-pinch experiments on the primary test stand (PTS). It is composed of a stack of 18 lead filters interspersed with 19 thermoluminescent dosimeters (TLD). A shield is constructed for the spectrometer and scattered radiation is reduced to less than 5% by the shield. Response functions of the spectrometer are calculated by MCNP5 for 0–2 MeV photons. Based on response functions and 19 dose data measured in experiments, energy spectra of high energy photons on PTS has been firstly obtained by unfolding programs developed with MATLAB code using iterative least square fit. Results show that energy peak locates within 200 keV and 300 keV, and the fluence decreases to background level at energy higher than 1.3 MeV.

  9. In-vivo dosimetry in radiotherapy: a comparison of the response of semiconductor and thermoluminescence (TLD700) dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Vynckier, S [Universite Catholique de Louvain, Brussels (Belgium). Cliniques Universitaires St. Luc; Greffe, J L; Loncol, T; Vanneste, F; Octave-Prignot, M; Denis, J M; De Patoul, N

    1995-12-01

    Semiconductor dosemeters and thermoluminescence dosemeters were calibrated in view of in-vivo dosimetry. Their response in a 8 MV photon beam and the respective correction factors for the treatment conditions were systematically studied. A total of 249 entrance and exit measurements with this dual detector combination were performed, mainly for treatments of the head and neck region. The resulting entrance and exit doses were compared with the expected doses at these positions, calculated on basis of the treatment and patient parameters. The results at the entrance showed a value of 1.010 (2.8% for the ratio of the measured to the calculated dose by diodes, 1.013) 4.9% for the ratio of the measured to the calculated dose by TLD and 1.003 (3.6% for the ratio of the measured dose by TLD to diodes. With respect the exit dose, the results were 0.998) 4.9%, 1.016 (7.7% and 1.019) 7.0% respectively after correction for the heterogeneity`s. Although the standard deviation for the TLD dosemeters is systematically larger than the standard deviation for the diodes, it is concluded that both dosemeters will yield similar results for-in-vivo dosimetry, if utilized under the same conditions.

  10. A Pb-TLD spectrometer to measure high energy photons in z-pinch experiments on the primary test stand

    Energy Technology Data Exchange (ETDEWEB)

    Si, Fenni; Yang, Jianlun; Xu, Rongkun; Yuan, Xi; Huang, Zhanchang; Ye, Fan; Wang, Dong; Zhang, Chuanfei, E-mail: sifenni@163.com

    2017-05-15

    Highlights: • A Pb-TLD spectrometer has been developed to measure spectra of high energy photons in wire-array z pinches on PTS. • Energy spectra of high energy photons on PTS has been firstly obtained by unfolding programs developed with MATLAB code. • The energy of high energy x-ray on PTS is obtained to be mainly within the region of 100 keV to 1.3 MeV. - Abstract: A Pb-TLD spectrometer has been developed based on attenuation techniques to measure high energy photons in wire-array z-pinch experiments on the primary test stand (PTS). It is composed of a stack of 18 lead filters interspersed with 19 thermoluminescent dosimeters (TLD). A shield is constructed for the spectrometer and scattered radiation is reduced to less than 5% by the shield. Response functions of the spectrometer are calculated by MCNP5 for 0–2 MeV photons. Based on response functions and 19 dose data measured in experiments, energy spectra of high energy photons on PTS has been firstly obtained by unfolding programs developed with MATLAB code using iterative least square fit. Results show that energy peak locates within 200 keV and 300 keV, and the fluence decreases to background level at energy higher than 1.3 MeV.

  11. Study of the influence of the time temperature profile on the minimum detectable dose of TLD-100

    International Nuclear Information System (INIS)

    Meireles, Leonardo S.; Lacerda, Marco Aurelio S.; Meira-Belo, Luiz C.; Ferreira, Hudson R.

    2013-01-01

    Monitoring of workers and workplaces is an integral part of any radiation protection programme (RPP). It is essential to demonstrate compliance with regulations that limit the allowable dose to the public from manmade sources and to enable the responsible of the installations to verify compliance with the legal dose limits to the workers and ALARA goals. Thermoluminescent dosemeters (TLDs) are generally employed to assess the environmental and personnel doses. To completely characterize a TLD dosimetry system is fundamental to determine the Lowest Dose that the system is capable of measuring. As the amount of the light emitted by TLD material is a function of the time temperature profile (TTP), in the present study, the influence of the TTP on the Detection Threshold (MDD) of the LiF:Mg,Ti (TLD-100) detectors was evaluated. Eighteen different TTPs were tested for two different annealing processes: (I) utilization of the TTP itself and; (II) a microprocessor controlled oven annealing procedure. Results showed that TTP choice can influence significantly in the MDD values. The worst results were generally found for TLDs annealed by the TTP itself. The lack of pattern or the unexpected behavior to the influence of some parameters of the TTP on the calculated MDDs must be carefully investigated. Greater variations on the TTP parameters must be undertaken. Special attention must be also done on the methodology of calculating the MDDs. (author)

  12. Neural Bases of Automaticity

    Science.gov (United States)

    Servant, Mathieu; Cassey, Peter; Woodman, Geoffrey F.; Logan, Gordon D.

    2018-01-01

    Automaticity allows us to perform tasks in a fast, efficient, and effortless manner after sufficient practice. Theories of automaticity propose that across practice processing transitions from being controlled by working memory to being controlled by long-term memory retrieval. Recent event-related potential (ERP) studies have sought to test this…

  13. Automatic control systems engineering

    International Nuclear Information System (INIS)

    Shin, Yun Gi

    2004-01-01

    This book gives descriptions of automatic control for electrical electronics, which indicates history of automatic control, Laplace transform, block diagram and signal flow diagram, electrometer, linearization of system, space of situation, state space analysis of electric system, sensor, hydro controlling system, stability, time response of linear dynamic system, conception of root locus, procedure to draw root locus, frequency response, and design of control system.

  14. Automatic Camera Control

    DEFF Research Database (Denmark)

    Burelli, Paolo; Preuss, Mike

    2014-01-01

    Automatically generating computer animations is a challenging and complex problem with applications in games and film production. In this paper, we investigate howto translate a shot list for a virtual scene into a series of virtual camera configurations — i.e automatically controlling the virtual...

  15. Automatic differentiation of functions

    International Nuclear Information System (INIS)

    Douglas, S.R.

    1990-06-01

    Automatic differentiation is a method of computing derivatives of functions to any order in any number of variables. The functions must be expressible as combinations of elementary functions. When evaluated at specific numerical points, the derivatives have no truncation error and are automatically found. The method is illustrated by simple examples. Source code in FORTRAN is provided

  16. Status of services, overexposure and QAC in TLD PMS to defence

    International Nuclear Information System (INIS)

    Rathore, A.S.; Gupta, D.K.; Samaria, H.C.; Chouhan, R.L.; Mishra, M.; Goyal, J.K.; Gautam, M.; Kalla, R.

    2008-01-01

    Individual monitoring has always played an important role in radiological protection. There is continuous development in the field of dosimetry systems and many changes have taken place in last many years. The use of radiation for peaceful purposes is increasing with advancement of technological growth in the country. Thermo luminescence dosimeters (TLDs) have emerged as one of the best alternatives for personal monitoring. Defence sector has nearly 2100 persons, who are working in various Military Hospitals, Military Colleges, DRDO Labs, Defence Ordinance factories and many others CPMFs like CISF, BSF, who are likely to receive radiation doses. Defence Laboratory, Jodhpur is providing the TLD personal monitoring service since Jan 1999 as per the guideline by B.A.R.C. to all the institutions mentioned above. This paper brings out salient features of this service in terms of facility available, procedures fulfilling the requirement of accreditation, over exposure reported, quality measures adopted and quality assurance results conducted by BARC, utility and suggestions for such type of services. (author)

  17. PTTL Dose Re-estimation Applied to Quality Control in TLD-100 Based Personal Dosimetry

    International Nuclear Information System (INIS)

    Muniz, J.L.; Correcher, V.; Delgado, A.

    1999-01-01

    A new method for quality control of dose performance in Personal Dosimetry using TLD-100 is presented. This method consists of the application of dose reassessment techniques based on phototransferred thermoluminescence (PTTL). Reassessment is achieved through a second TL readout of the dosemeters worn by the controlled workers, after a reproducible UV exposure. Recent refinements in the PTTL technique developed in our laboratory allow reassessing doses as low as 0.2 mSv, thus extending the reassessment capability to the entire dose range that must be monitored in personal dosimetry. After a one month exposure, even purely environmental doses can be reassessed. This method can be applied for either re-estimation of single doses or of the total dose accumulated after a number of exposures and dose measurements. Several tests to reconfirm low doses in normal working conditions for personal dosimetry have been performed. Each test consisted of several cycles of exposure and TL evaluations and a final PTTL re-estimation of the total accumulated dose in those cycles. The results obtained always showed very good agreement between the sum of the partial doses and the total reassessed dose. The simplicity of the method and the possibility of re-evaluating the doses assessed to the workers employing their own dosemeters are advantageous features to be considered in designing systems for the determination of real performance in personal dosimetry. (author)

  18. Measurement of dose to skin using TLD of several radiodiagnostic studies in San Jose, Costa Rica

    International Nuclear Information System (INIS)

    Mora, P.

    1998-01-01

    It is quantified the radiation doses on skin for several radiodiagnostic studies in patients of the Calderon Guardia Hospital in San Jose, Costa Rica at the period October 1997-September 1998 using thermoluminescent dosemeters TLD 100. The crystals receive the decoction standard procedures and they are arranged at the middle of the irradiation field. For a total of 973 radiodiagnostic studies it was found that the dose on skin in mGy are: 2.09 for thorax AP/AP, 5.33 for thorax LAT, 5.35 for skull AP/PA, 2.98 for skull LAT, 10.74 for abdomen, hips and pelvis, 6.20 for spines AP, 9.35 for spines LAT, 11.48 for lumbar columns AP, 29.99 for lumbar columns LAT and 6.87 for intravenous skin diagrams (first plate ap). It is produced thus the first reference bank for the national hospitals, which is compared with the orientation levels of doses for IAEA. Recommendations to diminish the collective doses through quality control programs are discussed, taking as goal to have got radiographs of excellent diagnostic quality, but with the less possible doses. (Author)

  19. 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)

  20. External radiation monitoring in TAPS and RAPS environs (1980-81) using TLD

    International Nuclear Information System (INIS)

    Basu, A.S.; Nambi, K.S.V.; Sunta, C.M.

    1983-01-01

    Results of environmental external radiation monitoring using quarterly integrated TLD measurements are presented for environments of the Tarapur Atomic Power Station (TAPS) and the Rajasthan Atomic Power Station (RAPS) for the two year monitoring period (1980-81). The data fit into the unimodal log-normal distribution except for locations where gaseous radioactivity escaping from the plant makes a significant contribution. The average natural radiation background in TAPS and RAPS environment is estimated to be 59.6 +- 4.7 mR yr -1 and 65.1 +- 9.8 mR yr -1 respectively. Contribution from the plant superimposed over the natural level leads frequently to bi-normal distribution. The effect of stack-released gaseous radioactivity is seen in locations within 1.6 km of TAPS: for example Ghivoli village registered an excess of 9.3 mR yr -1 over the natural background. The quarterly background values indicate minor temporal and spatial variations which can be attributed to changes in natural as well as stack released radioactivity. (author)

  1. Thermoluminescent dosemeters (TLD) exposed to high fluxes of gamma radiation, thermal neutrons and protons

    International Nuclear Information System (INIS)

    Gambarini, G.; Martini, M.; Meinardi, F.; Raffaglio, C.; Salvadori, P.; Scacco, A.; Sichirollo, A.E.

    1996-01-01

    Thermoluminescent dosemeters (TLD), widely experimented and utilized in personal dosimetry, have some advantageous characteristics which induce one to employ them also in radiotherapy. The new radiotherapy techniques are aimed at selectively depositing a high dose in cancerous tissues. This goal is reached by utilising both conventional and other more recently proposed radiation, such as thermal neutrons and heavy charged particles. In these inhomogeneous radiation fields a reliable mapping of the spatial distribution of absorbed dose is desirable, and the utilized dosemeters have to give such a possibility without notably perturbing the radiation field with the materials of the dosemeters themselves. TLDs, for their small dimension and their tissue equivalence for most radiation, give good support in the mapping of radiation fields. After exposure to the high fluxes of therapeutic beams, some commercial TL dosemeters have shown a loss of reliability. An investigation has therefore be performed, both on commercial and on laboratory made phosphors, in order to investigate their behaviour in such radiation fields. In particular the thermal neutron and gamma ray mixed field of the thermal column of a nuclear reactor, of interest for Boron Neutron Capture Therapy (B.N.C.T.) and a proton beam, of interest for proton therapy, were considered. Here some results obtained with new TL phosphors exposed in such radiation fields are presented, after a short description of some radiation damage effect on commercial LiF TLDs exposed in the (n th ,γ) field of the thermal column of a reactor. (author)

  2. Enhanced TDMA Based Anti-Collision Algorithm with a Dynamic Frame Size Adjustment Strategy for Mobile RFID Readers

    Directory of Open Access Journals (Sweden)

    Kwang Cheol Shin

    2009-02-01

    Full Text Available In the fields of production, manufacturing and supply chain management, Radio Frequency Identification (RFID is regarded as one of the most important technologies. Nowadays, Mobile RFID, which is often installed in carts or forklift trucks, is increasingly being applied to the search for and checkout of items in warehouses, supermarkets, libraries and other industrial fields. In using Mobile RFID, since the readers are continuously moving, they can interfere with each other when they attempt to read the tags. In this study, we suggest a Time Division Multiple Access (TDMA based anti-collision algorithm for Mobile RFID readers. Our algorithm automatically adjusts the frame size of each reader without using manual parameters by adopting the dynamic frame size adjustment strategy when collisions occur at a reader. Through experiments on a simulated environment for Mobile RFID readers, we show that the proposed method improves the number of successful transmissions by about 228% on average, compared with Colorwave, a representative TDMA based anti-collision algorithm.

  3. Enhanced TDMA Based Anti-Collision Algorithm with a Dynamic Frame Size Adjustment Strategy for Mobile RFID Readers.

    Science.gov (United States)

    Shin, Kwang Cheol; Park, Seung Bo; Jo, Geun Sik

    2009-01-01

    In the fields of production, manufacturing and supply chain management, Radio Frequency Identification (RFID) is regarded as one of the most important technologies. Nowadays, Mobile RFID, which is often installed in carts or forklift trucks, is increasingly being applied to the search for and checkout of items in warehouses, supermarkets, libraries and other industrial fields. In using Mobile RFID, since the readers are continuously moving, they can interfere with each other when they attempt to read the tags. In this study, we suggest a Time Division Multiple Access (TDMA) based anti-collision algorithm for Mobile RFID readers. Our algorithm automatically adjusts the frame size of each reader without using manual parameters by adopting the dynamic frame size adjustment strategy when collisions occur at a reader. Through experiments on a simulated environment for Mobile RFID readers, we show that the proposed method improves the number of successful transmissions by about 228% on average, compared with Colorwave, a representative TDMA based anti-collision algorithm.

  4. Metacognition and Reading: Comparing Three Forms of Metacognition in Normally Developing Readers and Readers with Dyslexia.

    Science.gov (United States)

    Furnes, Bjarte; Norman, Elisabeth

    2015-08-01

    Metacognition refers to 'cognition about cognition' and includes metacognitive knowledge, strategies and experiences (Efklides, 2008; Flavell, 1979). Research on reading has shown that better readers demonstrate more metacognitive knowledge than poor readers (Baker & Beall, 2009), and that reading ability improves through strategy instruction (Gersten, Fuchs, Williams, & Baker, 2001). The current study is the first to specifically compare the three forms of metacognition in dyslexic (N = 22) versus normally developing readers (N = 22). Participants read two factual texts, with learning outcome measured by a memory task. Metacognitive knowledge and skills were assessed by self-report. Metacognitive experiences were measured by predictions of performance and judgments of learning. Individuals with dyslexia showed insight into their reading problems, but less general knowledge of how to approach text reading. They more often reported lack of available reading strategies, but groups did not differ in the use of deep and surface strategies. Learning outcome and mean ratings of predictions of performance and judgments of learning were lower in dyslexic readers, but not the accuracy with which metacognitive experiences predicted learning. Overall, the results indicate that dyslexic reading and spelling problems are not generally associated with lower levels of metacognitive knowledge, metacognitive strategies or sensitivity to metacognitive experiences in reading situations. 2015 The Authors. Dyslexia Published by John Wiley & Sons Ltd.

  5. Alternative Text Types to Improve Reading Fluency for Competent to Struggling Readers

    Directory of Open Access Journals (Sweden)

    Timothy V. Rasinski

    2016-01-01

    Full Text Available This article offers instructional suggestions and strategies based on research and theoretical literature for developing reading fluency through the use of rhyming poetry and other texts beyond the narrative and informational texts that have been traditionally used for reading instruction. Readers’ lack of fluency in reading can be a monumental impediment to proficiency in good comprehension and overall reading competency. For all readers it is well established that as they progress in reading competence their reading ability grows (Stanovich, 1993/1994. This continued reading success begets continued reading growth; however, many struggling readers have difficulty in moving to a level of automaticity and fluency in their reading that enables them to engage in a successful practice. Lack of practice inhibits their reading comprehension. Readers’ abilities to effectively comprehend texts are significantly affected by their proficiency in accurate and automatic word recognition and prosody (May, 1998; Stanovich, 1993/1994; LaBerge & Samuels, 1974; Schreiber, 1991. Repeated reading practice has been shown to be a powerful way to improve these important fluency competencies. Certain texts are particularly well suited for repeated reading that improves both aspects of fluency

  6. Glycan Reader: Automated Sugar Identification and Simulation Preparation for Carbohydrates and Glycoproteins

    Science.gov (United States)

    Jo, Sunhwan; Song, Kevin C.; Desaire, Heather; MacKerell, Alexander D.; Im, Wonpil

    2011-01-01

    Understanding how glycosylation affects protein structure, dynamics, and function is an emerging and challenging problem in biology. As a first step toward glycan modeling in the context of structural glycobiology, we have developed Glycan Reader and integrated it into the CHARMM-GUI, http://www.charmm-gui.org/input/glycan. Glycan Reader greatly simplifies the reading of PDB structure files containing glycans through (i) detection of carbohydrate molecules, (ii) automatic annotation of carbohydrates based on their three-dimensional structures, (iii) recognition of glycosidic linkages between carbohydrates as well as N-/O-glycosidic linkages to proteins, and (iv) generation of inputs for the biomolecular simulation program CHARMM with the proper glycosidic linkage setup. In addition, Glycan Reader is linked to other functional modules in CHARMM-GUI, allowing users to easily generate carbohydrate or glycoprotein molecular simulation systems in solution or membrane environments and visualize the electrostatic potential on glycoprotein surfaces. These tools are useful for studying the impact of glycosylation on protein structure and dynamics. PMID:21815173

  7. [Survey among readers of the Tijdschrift voor Psychiatrie].

    Science.gov (United States)

    Brandt-Dominicus, J C; van Harten, P N

    2006-01-01

    The editorial board has defined the objectives of this journal as follows: to provide its readers with refreshing information, to report the results of scientific research and to build bridges between research and everyday practice. To find out what readers want and whether they support the board's objectives, and to use this information in planning the contents of future issues of the journal. All readers were invited to complete a questionnaire either on paper or via the website. Questionnaires were completed by 255 readers (response rate 5.7%). The average rating on a 5-point Likert scale was 3.8. Thematic issues and issues devoted to book reviews were given a high rating. There seems to be a demandfor evidence-based medicine, the inclusion of scientific results reported in other journals and practice-based articles. No significant differences were found between the views expressed by readers who had previously submitted an article for publication and those who had not, nor between Flemish readers and Dutch readers. The website was not visited very often. The Tijdschrift voor Psychiatrie is greatly appreciated by its readers. They are largely in agreement with the objectives formulated by the editorial board. Thematic issues are highly rated and many subjects are mentioned by the readers for future issues. The low response to the survey can affect its representativity. The editorial board will take readers' wishes into consideration when selecting material for future issues of the journal.

  8. Thai Automatic Speech Recognition

    National Research Council Canada - National Science Library

    Suebvisai, Sinaporn; Charoenpornsawat, Paisarn; Black, Alan; Woszczyna, Monika; Schultz, Tanja

    2005-01-01

    .... We focus on the discussion of the rapid deployment of ASR for Thai under limited time and data resources, including rapid data collection issues, acoustic model bootstrap, and automatic generation of pronunciations...

  9. Automatic Payroll Deposit System.

    Science.gov (United States)

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  10. Automatic Test Systems Aquisition

    National Research Council Canada - National Science Library

    1994-01-01

    We are providing this final memorandum report for your information and use. This report discusses the efforts to achieve commonality in standards among the Military Departments as part of the DoD policy for automatic test systems (ATS...

  11. Reader performance in visual assessment of breast density using visual analogue scales: Are some readers more predictive of breast cancer?

    Science.gov (United States)

    Rayner, Millicent; Harkness, Elaine F.; Foden, Philip; Wilson, Mary; Gadde, Soujanya; Beetles, Ursula; Lim, Yit Y.; Jain, Anil; Bundred, Sally; Barr, Nicky; Evans, D. Gareth; Howell, Anthony; Maxwell, Anthony; Astley, Susan M.

    2018-03-01

    Mammographic breast density is one of the strongest risk factors for breast cancer, and is used in risk prediction and for deciding appropriate imaging strategies. In the Predicting Risk Of Cancer At Screening (PROCAS) study, percent density estimated by two readers on Visual Analogue Scales (VAS) has shown a strong relationship with breast cancer risk when assessed against automated methods. However, this method suffers from reader variability. This study aimed to assess the performance of PROCAS readers using VAS, and to identify those most predictive of breast cancer. We selected the seven readers who had estimated density on over 6,500 women including at least 100 cancer cases, analysing their performance using multivariable logistic regression and Receiver Operator Characteristic (ROC) analysis. All seven readers showed statistically significant odds ratios (OR) for cancer risk according to VAS score after adjusting for classical risk factors. The OR was greatest for reader 18 at 1.026 (95% Cl 1.018-1.034). Adjusted Area Under the ROC Curves (AUCs) were statistically significant for all readers, but greatest for reader 14 at 0.639. Further analysis of the VAS scores for these two readers showed reader 14 had higher sensitivity (78.0% versus 42.2%), whereas reader 18 had higher specificity (78.0% versus 46.0%). Our results demonstrate individual differences when assigning VAS scores; one better identified those with increased risk, whereas another better identified low risk individuals. However, despite their different strengths, both readers showed similar predictive abilities overall. Standardised training for VAS may improve reader variability and consistency of VAS scoring.

  12. Skilled deaf readers have an enhanced perceptual span in reading.

    Science.gov (United States)

    Bélanger, Nathalie N; Slattery, Timothy J; Mayberry, Rachel I; Rayner, Keith

    2012-07-01

    Recent evidence suggests that, compared with hearing people, deaf people have enhanced visual attention to simple stimuli viewed in the parafovea and periphery. Although a large part of reading involves processing the fixated words in foveal vision, readers also utilize information in parafoveal vision to preprocess upcoming words and decide where to look next. In the study reported here, we investigated whether auditory deprivation affects low-level visual processing during reading by comparing the perceptual span of deaf signers who were skilled and less-skilled readers with the perceptual span of skilled hearing readers. Compared with hearing readers, the two groups of deaf readers had a larger perceptual span than would be expected given their reading ability. These results provide the first evidence that deaf readers' enhanced attentional allocation to the parafovea is used during complex cognitive tasks, such as reading.

  13. Brand and automaticity

    OpenAIRE

    Liu, J.

    2008-01-01

    A presumption of most consumer research is that consumers endeavor to maximize the utility of their choices and are in complete control of their purchasing and consumption behavior. However, everyday life experience suggests that many of our choices are not all that reasoned or conscious. Indeed, automaticity, one facet of behavior, is indispensable to complete the portrait of consumers. Despite its importance, little attention is paid to how the automatic side of behavior can be captured and...

  14. Position automatic determination technology

    International Nuclear Information System (INIS)

    1985-10-01

    This book tells of method of position determination and characteristic, control method of position determination and point of design, point of sensor choice for position detector, position determination of digital control system, application of clutch break in high frequency position determination, automation technique of position determination, position determination by electromagnetic clutch and break, air cylinder, cam and solenoid, stop position control of automatic guide vehicle, stacker crane and automatic transfer control.

  15. Automatic intelligent cruise control

    OpenAIRE

    Stanton, NA; Young, MS

    2006-01-01

    This paper reports a study on the evaluation of automatic intelligent cruise control (AICC) from a psychological perspective. It was anticipated that AICC would have an effect upon the psychology of driving—namely, make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but might reduce the workload and make driving might less stressful. Drivers were asked to drive in a driving simulator under manual and automatic inte...

  16. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia

    International Nuclear Information System (INIS)

    Sierra C, B. Y.; Jimenez, Y.; Plazas, M. C.; Eslava S, J.; Groot R, H.

    2014-08-01

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  17. Long-term TLD measurements of environmental background radiation in the New York City Area

    International Nuclear Information System (INIS)

    Maiello, M.

    1994-11-01

    The results of month-long TLD measurements at seven locations within 150 km of New York City are reported for 12 years at a few locations and for up to 18 years at others. At some locations, multiple dosimeters were deployed to acquire concurrent indoor and outdoor measurements. The sites were varied and include an urban high-rise residence, three suburban backyards, a rural hillside, and the wooded outskirts of a nuclear power plant (nonoperational). Long-term mean dose rates in air ranged from 50.8 to 123.1 nGy h -1 (5.8 to 14.1 μR h -1 ) across the area. The typical seasonal dose rate in air variations are presented for two of the sites and are briefly discussed in terms of soil conditions. The data indicate that it is possible to achieve monthly variations from the long-term mean as high as 20 to 40%. One of these locations was monitored for indoor (2 floors) and outdoor air dose rates. This allowed for a time series comparison to be performed illustrating the changing contribution of terrestrial radiation to the total dose rate relative to the steady building material-derived radioactivity. This site also permitted the calculation of indoor/outdoor ratios for two floors. Another suburban location yielded an indoor/outdoor ratio using ground floor dose-rate-in-air measurements. Also presented are mean annual dose rates in air showing a long-term decrease at some locations. A statistical Kendall test was performed to quantify the magnitude of the decrease. A definitive explanation of this trend requires further study

  18. Measurement of Thyroid Dose by TLD arising from Radiotherapy of Breast Cancer Patients from Supraclavicular Field

    Directory of Open Access Journals (Sweden)

    Farhood B.

    2016-06-01

    Full Text Available Background: Breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. Radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. The treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary fields. Objective: In the present study, due to the presence of sensitive organ such as thyroid inside the supraclavicular field, thyroid dose and its effective factors were investigated. Materials and Methods: Thyroid dose of 31 female patients of breast cancer with involved supraclavicular lymph nodes which had undergone radiotherapy were measured. For each patient, three TLD-100 chips were placed on their thyroid gland surface, and thyroid doses of patients were measured. The variables of the study include shield shape, the time of patient’s setup, the technologists’ experience and qualification. Finally, the results were analyzed by ANOVA test using SPSS 11.5 software. Results: The average age of the patients was 46±10 years. The average of thyroid dose of the patients was 140±45 mGy (ranged 288.2 and 80.8 in single fraction. There was a significant relationship between the thyroid dose and shield shape. There was also a significant relationship between the thyroid dose and the patient’s setup time. Conclusion: Beside organ at risk such as thyroid which is in the supraclavicular field, thyroid dose possibility should be reduced. For solving this problem, an appropriate shield shape, the appropriate time of the patient’s setup, etc. could be considered.

  19. Response analysis of TLD-300 dosimeters in heavy-particle beams

    International Nuclear Information System (INIS)

    Loncol, Th.; Hamal, M.; Vynckier, S.; Scalliet, P.; Denis, J.M.; Wambersie, A.

    1996-01-01

    In vivo dosimetry is recommended as part of the quality control procedure for treatment verification in radiation therapy. Using thermoluminescence, such controls are planned in the p(65)+Be neutron and 85 MeV proton beams produced at the cyclotron at Louvain-La-Neuve and dedicated to therapy applications. A preliminary study of the peak 3 (150 deg. C) and peak 5 (250 deg. C) response of CaF 2 :Tm (TLD-300) to neutron and proton beams aimed to analyse the effect of different radiation qualities on the dosimetric behaviour of the detector irradiated in phantom. To broaden the range of investigation, the study was extended to an experimental C-12 heavy ion beam (95 MeV/nucleon). The peak 3 and 5 sensitivities in the neutron beam, compared to Co-60, varied little with depth. A major change of peak 5 sensitivity was observed for samples positioned under five leaves of the multi-leaf collimator. While peak 3 sensitivity was constant with depth in the unmodulated proton beam, peak 5 sensitivity increased by 15%. Near the Bragg peak, peak 3 showed the highest decrease of sensitivity. In the modulated proton beam, the sensitivity values were not significantly smaller than those measured in the unmodulated beam far from the Bragg peak region. The ratio of the heights of peak 3 and peak 5 decreased by 70% from the Co-60 reference radiation to the C-12 heavy-ion beam. This parameter was strongly correlated with the change of radiation quality. (author)

  20. 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)

  1. Reception theory and the Christian reader: A preliminary perspective

    Directory of Open Access Journals (Sweden)

    A. L. Comhrink

    1983-03-01

    Full Text Available In recent years there has been a significant shift in emphasis from text- centred criticism in literature to reader-centred criticism. This new field of criticism, called Reception Theory or Reader Response Criticism, denies the immutable nature of the "text” and regards as its object of study the work of literature that is created through the co-constituent creative and interpre­tive acts o f both writer and reader.

  2. Readers Theatre : Dramatising environment issues for oral skills development

    OpenAIRE

    Paatrick Ng Chin Leong

    2009-01-01

    Readers Theatre was introduced to a class of Japanese students studying intermediate-level English in an international university in Japan. The aim of the study is to investingate whether Readers Theatre enhances the oral skills of Japanese students as they negotiate an environmental issue in English. In my presentation, I will demonstrate how Readers Theatre is implemented in class and the comments by students will be analysed and discussed during the presentation.

  3. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study.

    Science.gov (United States)

    Koivisto, J; Schulze, D; Wolff, J; Rottke, D

    2014-01-01

    The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Organ and effective dose measurements were performed using 40 TLD and 20 MOSFET dosemeters that were alternately placed in 20 different locations in 1 anthropomorphic RANDO(®) head phantom (the Phantom Laboratory, Salem, NY). The phantom was exposed to four different CBCT default maxillofacial protocols using small (4 × 5 cm) to full face (20 × 17 cm) fields of view (FOVs). The TLD effective doses ranged between 7.0 and 158.0 µSv and the MOSFET doses between 6.1 and 175.0 µSv. The MOSFET and TLD effective doses acquired using four different (FOV) protocols were as follows: face maxillofacial (FOV 20 × 17 cm) (MOSFET, 83.4 µSv; TLD, 87.6 µSv; -5%); teeth, upper jaw (FOV, 8.5 × 5.0 cm) (MOSFET, 6.1 µSv; TLD, 7.0 µSv; -14%); tooth, mandible and left molar (FOV, 4 × 5 cm) (MOSFET, 10.3 µSv; TLD, 12.3 µSv; -16%) and teeth, both jaws (FOV, 10 × 10 cm) (MOSFET, 175 µSv; TLD, 158 µSv; +11%). The largest variation in organ and effective dose was recorded in the small FOV protocols. Taking into account the uncertainties of both measurement methods and the results of the statistical analysis, the effective doses acquired using MOSFET dosemeters were found to be in good agreement with those obtained using TLD dosemeters. The MOSFET dosemeters constitute a feasible alternative for TLDs for the effective dose assessment of CBCT devices in the maxillofacial region.

  4. The e-Reader — an Educational or an Entertainment Tool? e-Readers in an Academic Setting

    Directory of Open Access Journals (Sweden)

    Peter Ahlroos

    2012-01-01

    Full Text Available In this paper the authors will discuss a pilot project conducted at the Tritonia Academic Library, Vaasa, in Finland, from September 2010 until May 2011. The project was designed to investigate the application of e-readers in academic settings and to learn how teachers and students experience the use of e-readers in academic education. Four groups of students and one group of teachers used Kindle readers for varied periods of time in different courses. The course material and the textbooks were downloaded on the e-readers. The feedback from the participants was collected through questionnaires and teacher interviews. The results suggest that the e-reader is a future tool for learning, though some features need to be improved before e-readers can really enable efficient learning and researching.

  5. Evaluating secondary neutron doses of a refined shielded design for a medical cyclotron using the TLD approach

    International Nuclear Information System (INIS)

    Lin, Jye-Bin; Tseng, Hsien-Chun; Liu, Wen-Shan; Lin, Ding-Bang; Hsieh, Teng-San; Chen, Chien-Yi

    2013-01-01

    An increasing number of cyclotrons at medical centers in Taiwan have been installed to generate radiopharmaceutical products. An operating cyclotron generates immense amounts of secondary neutrons from reactions such the 18 O(p, n) 18 F, used in the production of FDG. This intense radiation can be hazardous to public health, particularly to medical personnel. To increase the yield of 18 F-FDG from 4200 GBq in 2005 to 48,600 GBq in 2011, Chung Shan Medical University Hospital (CSMUH) has prolonged irradiation time without changing the target or target current to meet requirements regarding the production 18 F. The CSMUH has redesigned the CTI Radioisotope Delivery System shield. The lack of data for a possible secondary neutron doses has increased due to newly designed cyclotron rooms. This work aims to evaluate secondary neutron doses at a CTI cyclotron center using a thermoluminescent dosimeter (TLD-600). Two-dimensional neutron doses were mapped and indicated that neutron doses were high as neutrons leaked through self-shielded blocks and through the L-shaped concrete shield in vault rooms. These neutron doses varied markedly among locations close to the H 2 18 O target. The Monte Carlo simulation and minimum detectable dose are also discussed and demonstrated the reliability of using the TLD-600 approach. Findings can be adopted by medical centers to identify radioactive hot spots and develop radiation protection. - Highlights: • Neutron doses were verified using TLD approach. • Neutron doses were increased at cyclotron centers. • Revised L-shaped shield suppresses effectively the neutrons. • Neutron dose can be attenuated to 1.13×10 6 %

  6. The intercomparison of 137Cs irradiator output measurement and personal dose equivalent, Hp(10), using TLD and film

    International Nuclear Information System (INIS)

    Nazaroh; Susetyo Trijoko; Sri Inang Sunaryati

    2010-01-01

    Intercomparison of output measurement of 137 Cs irradiator and personal dose equivalent, Hp(10) using TLD and film have been carried out in the year of 2006 to 2008. According to IAEA recommendation, intercomparison is one of audit activities but it is performed in the spirit of collaboration and support rather than in the spirit of inspection. The aim of intercomparison of output measurement of 137 Cs irradiator is to verify the dose stated by the participant laboratories. Intercomparison is also to assess the competency of the participant, to keep traceability and consistency of measurement result, to assure that instrument work correctly and the result of evaluation was in agreement, and also for fulfilling one of the clauses of ISO-17025-2005. Besides that, this intercomparison aimed to facilitate link between the system and members of national measurement and transfer of experience in measurement technique and dose evaluation of radiation. The benefit of intercomparison is important among others as tests of proficiency in dose evaluation or measurement, upgrading quality of service and for obeying supervisor body legislation (BAPETEN). TLD was used as a means of output 137 Cs irradiator measurement, whereas film and TLD were used for dose intercomparison. This paper presented result of intercomparison of output measurement and evaluation of personal dose equivalent, Hp(10) in the year of 2006 to 2008 followed by 6 participants: Balai Pengamanan Fasilitas Kesehatan (BPFK) Jakarta, Medan, Surabaya, Makasar, PTLR and Laboratory of Keselamatan dan Kesehatan Lingkungan (KKL)-PTKMR BATAN. In this intercomparison, the dose of TLD stated by participant were compared with the dose measured by Radiation Metrology Laboratory (LMR), and the results showed the differences were within 10 %, so it was satisfied. The results of intercomparison of personal dose equivalent, Hp(10) were evaluated based on ISO/IEC Guide 43-1, 1997 analysis and expressed as E n . The values of E n

  7. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon

    International Nuclear Information System (INIS)

    Avila, O.; Rodriguez V, M.; Aviles, P.; Gamboa de Buen, I.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E.

    2002-01-01

    In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

  8. In vivo TLD-measurement of the radiation burden after intake of sup(99m)Tc-labelled compounds

    International Nuclear Information System (INIS)

    Kletter, K.; Frischauf, H.; Dudczak, R.; Nowotny, R.

    1978-01-01

    Organ and whole-body radiation doses by sup(99m)Tc labelled preparations were measured on patients subjected to scintigraphy of liver (+spleen), thyroid of kidneys. Body surface doses were determined by means of TLD-100 (LiF) dosimeters. From these values organ doses were calculated by inference from surface and organ measurements on a Remcal - Alderson phantom which also served to examine the influence of variable fat layers on the surface doses. The results were compared with data calculated from pharmacokinetic measurements of organ uptake as well as blood and urine activity. Both methods gave corresponding results. (author)

  9. Usefulness of semi-automatic volumetry compared to established linear measurements in predicting lymph node metastases in MSCT

    Energy Technology Data Exchange (ETDEWEB)

    Buerke, Boris; Puesken, Michael; Heindel, Walter; Wessling, Johannes (Dept. of Clinical Radiology, Univ. of Muenster (Germany)), email: buerkeb@uni-muenster.de; Gerss, Joachim (Dept. of Medical Informatics and Biomathematics, Univ. of Muenster (Germany)); Weckesser, Matthias (Dept. of Nuclear Medicine, Univ. of Muenster (Germany))

    2011-06-15

    Background Volumetry of lymph nodes potentially better reflect asymmetric size alterations independently of lymph node orientation in comparison to metric parameters (e.g. long-axis diameter). Purpose To distinguish between benign and malignant lymph nodes by comparing 2D and semi-automatic 3D measurements in MSCT. Material and Methods FDG-18 PET-CT was performed in 33 patients prior to therapy for malignant melanoma at stage III/IV. One hundred and eighty-six cervico-axillary, abdominal and inguinal lymph nodes were evaluated independently by two radiologists, both manually and with the use of semi-automatic segmentation software. Long axis (LAD), short axis (SAD), maximal 3D diameter, volume and elongation were obtained. PET-CT, PET-CT follow-up and/or histology served as a combined reference standard. Statistics encompassed intra-class correlation coefficients and ROC curves. Results Compared to manual assessment, semi-automatic inter-observer variability was found to be lower, e.g. at 2.4% (95% CI 0.05-4.8) for LAD. The standard of reference revealed metastases in 90 (48%) of 186 lymph nodes. Semi-automatic prediction of lymph node metastases revealed highest areas under the ROC curves for volume (reader 1 0.77, 95%CI 0.64-0.90; reader 2 0.76, 95%CI 0.59-0.86) and SAD (reader 1 0.76, 95%CI 0.64-0.88; reader 2 0.75, 95%CI 0.62-0.89). The findings for LAD (reader 1 0.73, 95%CI 0.60-0.86; reader 2 0.71, 95%CI 0.71, 95%CI 0.57-0.85) and maximal 3D diameter (reader 1 0.70, 95%CI 0.53-0.86; reader 2 0.76, 95%CI 0.50-0.80) were found substantially lower and for elongation (reader 1 0.65, 95%CI 0.50-0.79; reader 2 0.66, 95%CI 0.52-0.81) significantly lower (p < 0.05). Conclusion Semi-automatic analysis of lymph nodes in malignant melanoma is supported by high segmentation quality and reproducibility. As compared to established SAD, semi-automatic lymph node volumetry does not have an additive role for categorizing lymph nodes as normal or metastatic in malignant

  10. Calibration of a TLD system to estimate personal doses in fields of gamma-neutrons radiation

    International Nuclear Information System (INIS)

    Villegas, E.N.; Somarriba, S.I.

    2016-01-01

    Currently Nicaragua has no personal neutron dosimetry system. The calibration of a batch of albedo neutron dosimeters consisting of two pairs of "6LiF and "7LiF (Mg, Ti) detectors was done. The dosimeter and reader sensitivities were obtained using a "1"3"7Cs source, and a neutron calibration factor was found with a "2"4"1AmBe source. Reproducibility and homogeneity tests were performed, and the detection limit of the system was determined. This calibration will allow the beginning of neutron personal monitoring in the country. (author)

  11. Semi-automatic analysis of standard uptake values in serial PET/CT studies in patients with lung cancer and lymphoma

    Directory of Open Access Journals (Sweden)

    Ly John

    2012-04-01

    Full Text Available Abstract Background Changes in maximum standardised uptake values (SUVmax between serial PET/CT studies are used to determine disease progression or regression in oncologic patients. To measure these changes manually can be time consuming in a clinical routine. A semi-automatic method for calculation of SUVmax in serial PET/CT studies was developed and compared to a conventional manual method. The semi-automatic method first aligns the serial PET/CT studies based on the CT images. Thereafter, the reader selects an abnormal lesion in one of the PET studies. After this manual step, the program automatically detects the corresponding lesion in the other PET study, segments the two lesions and calculates the SUVmax in both studies as well as the difference between the SUVmax values. The results of the semi-automatic analysis were compared to that of a manual SUVmax analysis using a Philips PET/CT workstation. Three readers did the SUVmax readings in both methods. Sixteen patients with lung cancer or lymphoma who had undergone two PET/CT studies were included. There were a total of 26 lesions. Results Linear regression analysis of changes in SUVmax show that intercepts and slopes are close to the line of identity for all readers (reader 1: intercept = 1.02, R2 = 0.96; reader 2: intercept = 0.97, R2 = 0.98; reader 3: intercept = 0.99, R2 = 0.98. Manual and semi-automatic method agreed in all cases whether SUVmax had increased or decreased between the serial studies. The average time to measure SUVmax changes in two serial PET/CT examinations was four to five times longer for the manual method compared to the semi-automatic method for all readers (reader 1: 53.7 vs. 10.5 s; reader 2: 27.3 vs. 6.9 s; reader 3: 47.5 vs. 9.5 s; p Conclusions Good agreement was shown in assessment of SUVmax changes between manual and semi-automatic method. The semi-automatic analysis was four to five times faster to perform than the manual analysis. These findings show the

  12. Co-editors’ Note to Readers

    Directory of Open Access Journals (Sweden)

    Wen-hsin Yeh

    2015-06-01

    Full Text Available Dear Cross-Currents readers, We are pleased to present you with the fifteenth quarterly issue of the Cross-Currents e-journal. The research articles in the June 2015 issue—guest edited by Elena Barabantseva (University of Manchester, Xiang Biao (University of Oxford, and Antonia Chao (Tunghai University—explore the theme “Governing Marriage Migrations: Perspectives from Mainland China and Taiwan.” The issue includes five articles by scholars from Japan, Germany, the UK, Taiwan, and Hong Kong who are engaged in critical analysis of cross-border migration for the purpose of marriage in the People’s Republic of China and Taiwan as a subject of governance. As the guest editors emphasize in their introduction, cross-border marriage is “perceived to be inseparable from a wide range of other issues, such as sexual morality, family norms, national identity, and border security.” The contributors—Hongfang Hao (Kyoto University, Caroline Grillot (Max Planck Institute for Social Anthropology, Elena Barabantseva (University of Manchester, Mei-Hua Chen (National Sun Yat-sen University, and Hsun-Hui Tseng (Chinese University of Hong Kong—offer valuable new insights on international marriage migration in their multidisciplinary and fieldwork-based studies...

  13. Automatic analog IC sizing and optimization constrained with PVT corners and layout effects

    CERN Document Server

    Lourenço, Nuno; Horta, Nuno

    2017-01-01

    This book introduces readers to a variety of tools for automatic analog integrated circuit (IC) sizing and optimization. The authors provide a historical perspective on the early methods proposed to tackle automatic analog circuit sizing, with emphasis on the methodologies to size and optimize the circuit, and on the methodologies to estimate the circuit’s performance. The discussion also includes robust circuit design and optimization and the most recent advances in layout-aware analog sizing approaches. The authors describe a methodology for an automatic flow for analog IC design, including details of the inputs and interfaces, multi-objective optimization techniques, and the enhancements made in the base implementation by using machine leaning techniques. The Gradient model is discussed in detail, along with the methods to include layout effects in the circuit sizing. The concepts and algorithms of all the modules are thoroughly described, enabling readers to reproduce the methodologies, improve the qual...

  14. Experimental comparison of profiles of acquired small fields with ionization chambers, diodes, radiochromic s and TLD films; Comparacion experimental de perfiles de campos pequenos adquiridos con camaras de ionizacion, diodos, peliculas radiocromicas y TLD

    Energy Technology Data Exchange (ETDEWEB)

    Venencia, D.; Garrigo, E. [Instituto Privado de Radioterapia, Obispo Oro 423, X5000BFI Cordoba (Argentina); Filipuzzi, M. [Instituto Balseiro, Centro Atomico Bariloche, Av. Bustillo 9500, 8400 Bariloche - Rio Negro (Argentina); Germanier, A., E-mail: devenencia@radioncologia-zunino.org [Centro de Excelencia en Productos y Procesos, Santa Maria de Punilla, 5164 Cordoba (Argentina)

    2014-08-15

    The use of radiation small fields, introduced by new techniques, can bring a considerable uncertainty in the precision of the acquired profiles, due to the conditions of lateral electronic non-equilibrium and the perturbations introduced by the detectors (volume effect and alteration of the charged particles flowing) [Das et al., 2007]. The development of new miniature detectors looks to diminish the uncertainty created by the material and the size of the sensitive volume of the dosimeter. For this reason, comparative measurements for three sizes of square field were carried out (20 mm, 10 mm and 5 mm, of side) using a detectors series: 3 ionization chambers (PTW-31003, IBA-CC04, PTW-31016), 2 diodes (PTW-60012, IBA-Sfd), thermoluminescent detectors micro-cubes of 1 mm of edge (TLD-700) and radiochromic s films EBT-3. These last two were used as reference detectors, due to their spatial high resolution and similar performance with Monte Carlo simulations [Francescon et al., 1998]. So much the thermoluminescent detectors as the radiochromic films resolved the profiles in a similar way. Both diodes responded correctly, but the rest of the detectors overestimated the gloom of the fields, which allows conclude that the used TLD (and both diodes) can resolve field sizes correctly, usually utilized in radio-surgery, without producing significant alterations in the acquired data. (author)

  15. Breaking the Silence: Toward Improving LGBTQ Representation in Composition Readers

    Science.gov (United States)

    Hudson, John

    2014-01-01

    Lesbian-Gay-Bisexual-Transgender-Queer (LGBTQ) representation in composition readers remains limited and is frequently nonexistent. In addition, the LGBTQ-related materials that do find their way into composition readers are often problematic. In this essay I explain why WPAs and composition teachers should be concerned about LGBTQ representation…

  16. Accelerated Reader Program: What Do Teachers Really Think?

    Science.gov (United States)

    Smith, Amy Frances; Westberg, Karen; Hejny, Anne

    2017-01-01

    What do teachers really think about the Accelerated Reader program, a widely used supplemental, independent reading program in which their students read fiction and non-fiction books of their choice and take brief online comprehension quizzes about the books? The Accelerated Reader (AR) program was designed by Renaissance Learning Company to…

  17. Eye Movements Reveal Readers' Lexical Quality and Reading Experience

    Science.gov (United States)

    Taylor, Jessica Nelson; Perfetti, Charles A.

    2016-01-01

    Two experiments demonstrate that individual differences among normal adult readers, including lexical quality, are expressed in silent reading at the word level. In the first of two studies we identified major dimensions of variability among college readers and among words using factor analysis. We then examined the effects of these dimensions of…

  18. Infographics for Educational Purposes: Their Structure, Properties and Reader Approaches

    Science.gov (United States)

    Yildirim, Serkan

    2016-01-01

    Infographics are one of the new educational environments used to provide information to their readers in a visual way. Infographics are designed to provide information to their readers using various visuals such as texts, pictures, drawings, diagrams, graphs, etc. The use of infographics becomes increasingly widespread both in advertising…

  19. How the Relationship between Text and Headings Influences Readers' Memory

    Science.gov (United States)

    Ritchey, Kristin; Schuster, Jonathan; Allen, Jaryn

    2008-01-01

    Two questions regarding signals' influence on memory were examined. First, the relationship between headings and text was manipulated to determine whether headings serve as visual cues, directing readers to recall all subsequent information, or content-specific cues, directing readers to recall only to certain information. Second, distance between…

  20. Are You Ready for E-Readers in Your Library?

    Science.gov (United States)

    Gustafson, Chris

    2012-01-01

    This article discusses some things to consider when thinking about adding e-readers to one's collection. These include: (1) What is the purpose?; (2) Which device?; (3) How will one keep track of his or her e-readers and their contents?; (4) What are some potential pitfalls?; (5) Is there a positive impact on student learning?; and (6) Are…

  1. Sexism Springs Eternal--in the Reader's Digest.

    Science.gov (United States)

    Zimbardo, Philip G.; Meadow, Wendy

    This document reports on an empirical investigation of anti-women humor appearing in the Reader's Digest over three decades, revealing the operation of an unconscious sexist ideology. A systematic analysis was made of 1,069 jokes appearing in two featured columns of the Reader's Digest for the two-year periods 1947-48, 1957-58, and 1967-68.…

  2. A Comparative Review of Stratification Texts and Readers

    Science.gov (United States)

    Peoples, Clayton D.

    2012-01-01

    Social stratification is a core substantive area within sociology. There are a number of textbooks and readers available on the market that deal with this central topic. In this article, I conduct a comparative review of (a) four stratification textbooks and (b) four stratification readers. (Contains 2 tables.)

  3. Chinese Deaf Readers Have Early Access to Parafoveal Semantics

    Science.gov (United States)

    Yan, Ming; Pan, Jinger; Bélanger, Nathalie N.; Shu, Hua

    2015-01-01

    In the present study, we manipulated different types of information available in the parafovea during the reading of Chinese sentences and examined how deaf readers make use of the parafoveal information. Results clearly indicate that although the reading-level matched hearing readers make greater use of orthographic information in the parafovea,…

  4. Resolving Struggling Readers' Homework Difficulties: A Social Cognitive Perspective

    Science.gov (United States)

    Margolis, Howard; Mccabe, Patrick

    2004-01-01

    Struggling readers often fail to complete homework or complete it in a slipshod, haphazard fashion. Often, this adversely affects grades, erodes motivation for academics, and causes conflict between readers, parents, and school personnel. To help teachers and educational consultants (e.g., reading specialists, school psychologists) help struggling…

  5. Organizing Instruction for Struggling Readers in Tutorial Settings

    Science.gov (United States)

    Mokhtari, Kouider; Hutchison, Amy C.; Edwards, Patricia A.

    2010-01-01

    In this article, the authors suggest that many of the problems struggling readers encounter while reading stem from distinct yet fundamental sources of difficulty related to the types of text read (print or online), the task or activity readers engage in, and the sociocultural context of reading. The authors further argue that although these…

  6. Addressing Learning Disabilities with UDL and Technology: Strategic Reader

    Science.gov (United States)

    Hall, Tracey E.; Cohen, Nicole; Vue, Ge; Ganley, Patricia

    2015-01-01

    CAST created "Strategic Reader," a technology-based system blending Universal Design for Learning (UDL) and Curriculum-Based Measurement (CBM) in a digital learning environment to improve reading comprehension instruction. This experimental study evaluates the effectiveness of Strategic Reader using two treatment conditions for measuring…

  7. Peace Pilgrim: A Readers Theatre Approach to Peace Education.

    Science.gov (United States)

    Curran, Joanne M.

    Readers theater is a dramatic art that directs attention to the words of a text. During a performance, a reader (rather than an actor) presents and interprets the work within a narrative context intended by the author. In this project, the text, a collection of the words and writings of a woman known as the Peace Pilgrim, tells the story of her…

  8. Finding versus Fixing: Self-Monitoring for Readers Who Struggle

    Science.gov (United States)

    Anderson, Nancy L.; Kaye, Elizabeth L.

    2017-01-01

    This article explains how teachers can understand, notice, and supportively respond to readers who struggle with self-monitoring during text reading. The unique strategic processing demands for readers who struggle support the argument that teaching children to find and notice errors is different than fixing a word, or getting it right. Three…

  9. Automatic Program Development

    DEFF Research Database (Denmark)

    Automatic Program Development is a tribute to Robert Paige (1947-1999), our accomplished and respected colleague, and moreover our good friend, whose untimely passing was a loss to our academic and research community. We have collected the revised, updated versions of the papers published in his...... honor in the Higher-Order and Symbolic Computation Journal in the years 2003 and 2005. Among them there are two papers by Bob: (i) a retrospective view of his research lines, and (ii) a proposal for future studies in the area of the automatic program derivation. The book also includes some papers...... by members of the IFIP Working Group 2.1 of which Bob was an active member. All papers are related to some of the research interests of Bob and, in particular, to the transformational development of programs and their algorithmic derivation from formal specifications. Automatic Program Development offers...

  10. LESS SKILLED READERS HAVE LESS EFFICIENT SUPPRESSION MECHANISMS.

    Science.gov (United States)

    Gernsbacher, Morton Ann

    1993-09-01

    One approach to understanding the component processes and mechanisms underlying adult reading skill is to compare the performance of more skilled and less skilled readers on laboratory experiments. The results of some recent experiments employing this approach demonstrate that less skilled adult readers suppress less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meanings of spade ), the incorrect forms of homophones (e.g., patients vs. patience ), the typical-but-absent members of scenes (e.g., a tractor in a farm scene), and words superimposed on pictures. Less skilled readers are not less efficient in activating contextually appropriate information; in fact, they activate contextually appropriate information more strongly than more skilled readers do. Therefore, one conclusion that can be drawn from these experiments is that less skilled adult readers suffer from less efficient suppression mechanisms.

  11. Overview of PADC nuclear track readers. Recent trends and solutions

    International Nuclear Information System (INIS)

    Hulber, E.

    2009-01-01

    The development of automated track readers dates back to the first routine dosimetry applications of solid state nuclear track detectors. Many research-laboratory track readers and a few commercial systems were introduced in the past 25 years. The traditional application area for high-throughput track readers is radon testing in buildings and fast neutron dosimetry. The latter application, in particular, has considerably increased the need for efficient polyallyldiglycol carbonate (PADC) track reader systems with high throughput. The paper provides an overview of recent trends in the development of high-throughput PADC track readers and it gives a glimpse into the practice of designing this category of devices. A general overview is provided of the technical aspects relating to the optics, the hardware and the track recognition approaches. Ultimate theoretical limits in the performance as well as promising new approaches are addressed. Requirements and practical solutions are illustrated with reference to a commercially available system.

  12. SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Lin, Y [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Chen, H [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Tsai, H [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Healthy Aging Research Center, Chang Gung University, Linkou, Taoyuan, Taiwan (China)

    2015-06-15

    Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ({sup 6}LiF: Mg, Ti) and TLD-700 ({sup 7}LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

  13. SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

    International Nuclear Information System (INIS)

    Chen, Y; Lin, Y; Chen, H; Tsai, H

    2015-01-01

    Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ( 6 LiF: Mg, Ti) and TLD-700 ( 7 LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

  14. Automatic text summarization

    CERN Document Server

    Torres Moreno, Juan Manuel

    2014-01-01

    This new textbook examines the motivations and the different algorithms for automatic document summarization (ADS). We performed a recent state of the art. The book shows the main problems of ADS, difficulties and the solutions provided by the community. It presents recent advances in ADS, as well as current applications and trends. The approaches are statistical, linguistic and symbolic. Several exemples are included in order to clarify the theoretical concepts.  The books currently available in the area of Automatic Document Summarization are not recent. Powerful algorithms have been develop

  15. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  16. Automatic NAA. Saturation activities

    International Nuclear Information System (INIS)

    Westphal, G.P.; Grass, F.; Kuhnert, M.

    2008-01-01

    A system for Automatic NAA is based on a list of specific saturation activities determined for one irradiation position at a given neutron flux and a single detector geometry. Originally compiled from measurements of standard reference materials, the list may be extended also by the calculation of saturation activities from k 0 and Q 0 factors, and f and α values of the irradiation position. A systematic improvement of the SRM approach is currently being performed by pseudo-cyclic activation analysis, to reduce counting errors. From these measurements, the list of saturation activities is recalculated in an automatic procedure. (author)

  17. Use of TL - dosimeters of TLD - 500K type for precision estimation of spatial distributions of mixed dose fields in 'Ukryttia' conditions

    CERN Document Server

    Lagutin, I G; Ershova, N N

    2003-01-01

    In some works being currently carried out in ISTC 'Ukryttia' divisions within the framework of 'Complex program of works at 'Ukryttia' object', a necessary arose to estimate local values of radiation dose fields of mixed type (beta + gamma). The most convenient tool for estimation of local values of long - term integrals of such doses are dosimeters fabricated on the basis of thermoluminescent detectors (TLD) having small sensitive volume under sufficient radiating capacity, convenient performance and high reproducibility of results. It was offered to use TL - detectors of TLD-500K type on the basis of sapphire monocrystal (alpha-Al sub 2 O sub 3).

  18. Difficulty in estimation of dose for the abnormal patterns of the TLD disc readings - need investigation and improvement in work practices

    International Nuclear Information System (INIS)

    Madhumita, B.; Ande, C.D.; Sneha, C.; Bakshi, A.K.; Datta, D.

    2018-01-01

    TLD badge based on CaSO 4 :Dy detector used for external radiation monitoring of occupational workers of radiation facilities in India plays a vital role in radiation protection program. Energy and type of radiation in the work-field can be well identified from the dose evaluation algorithm. Algorithm developed earlier use the set of disc ratio from the three disc readings of the TLD badge to arrive at the dose and the type of radiation. Algorithm fails to estimate the dose for the abnormal patterns. The paper discusses the root cause of the abnormal patterns and investigation followed to arrive the estimation of dose

  19. Image-guided method for TLD-based in vivo rectal dose verification with endorectal balloon in proton therapy for prostate cancer

    International Nuclear Information System (INIS)

    Hsi, Wen C.; Fagundes, Marcio; Zeidan, Omar; Hug, Eugen; Schreuder, Niek

    2013-01-01

    Purpose: To present a practical image-guided method to position an endorectal balloon that improves in vivo thermoluminiscent dosimeter (TLD) measurements of rectal doses in proton therapy for prostate cancer. Methods: TLDs were combined with endorectal balloons to measure dose at the anterior rectal wall during daily proton treatment delivery. Radiopaque metallic markers were employed as surrogates for balloon position reproducibility in rotation and translation. The markers were utilized to guide the balloon orientation during daily treatment employing orthogonal x-ray image-guided patient positioning. TLDs were placed at the 12 o'clock position on the anterior balloon surface at the midprostatic plane. Markers were placed at the 3 and 9 o'clock positions on the balloon to align it with respect to the planned orientation. The balloon rotation along its stem axis, referred to as roll, causes TLD displacement along the anterior-posterior direction. The magnitude of TLD displacement is revealed by the separation distance between markers at opposite sides of the balloon on sagittal x-ray images. Results: A total of 81 in vivo TLD measurements were performed on six patients. Eighty-three percent of all measurements (65 TLD readings) were within +5% and −10% of the planning dose with a mean of −2.1% and a standard deviation of 3.5%. Examination of marker positions with in-room x-ray images of measured doses between −10% and −20% of the planned dose revealed a strong correlation between balloon roll and TLD displacement posteriorly from the planned position. The magnitude of the roll was confirmed by separations of 10–20 mm between the markers which could be corrected by manually adjusting the balloon position and verified by a repeat x-ray image prior to proton delivery. This approach could properly correct the balloon roll, resulting in TLD positioning within 2 mm along the anterior-posterior direction. Conclusions: Our results show that image-guided TLD

  20. Calibration of TLD badge to photons of energies above 6 MeV encountered in nuclear reactors

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Bakshi, A.K.

    1999-01-01

    Response of CaSO 4 :Dy Teflon discs based TLD badge has been evaluated for radiation fields having photons of energy above 6 MeV, often encountered in nuclear power plants. Gamma ray response of the TLD disc under metal filter in the badge (used for evaluation of gamma ray doses) was found to increase by about 10% to photons above 6 MeV as compared to the response for reference calibration to 60 Co gamma rays. Response of discs under the open window and the plastic filter was found to be only 40-60% of that under metal filter. Thus, while measurement of whole body dose is not affected seriously, the estimation of beta dose in the mixed fields of high energy gamma rays and beta rays could be in serious error. In the above fields for situations having beta doses of about 1.65 times the gamma ray doses, the present use of dose evaluation will record beta dose as zero, a serious under estimation of beta ray doses. Study also provides an explanation to an anomalous situation where reading under window or plastic filter is much less than that under metal filter. These aspects of personal dosimetry need attention. (author)

  1. Design of photon energy compensation filters for the new four element CaSO4:Dy TLD badge

    International Nuclear Information System (INIS)

    Mishra, D.R.; Kulkarni, M.S.; Pradeep, Ratna; Kannan, S.

    2001-01-01

    A new four element TLD badge using CaSO 4 :Dy is being developed for the estimation of personal dose equivalents Hp(10) and Hp(0.07) and to discriminate them in the mix field (low energy x-ray and high energy γ-ray). Design of energy compensation filters for the new TLD badge is discussed. The total metal filter thickness is kept less than 1 mm. The first and second elements of the badge are planned to be open and plastic (≅180 gm/cm 2 ) window. For the third element a combination of 0.2 mm Sn + 0.7mm Cu + 0.1 mm Al with mass thickness ≅ 1100 mg/cm 2 is proposed which gives energy dependent response similar to Hp(10) within ± 20% (above 80 keV). For the fourth dosimeter a filter combination of 0.4 mm Al + 0.07 mm Sn is proposed which gives Hp(10)xR response for diagnostic x-rays within ± 10% in the mix field. (author)

  2. Experimental comparison of profiles of acquired small fields with ionization chambers, diodes, radiochromic s and TLD films

    International Nuclear Information System (INIS)

    Venencia, D.; Garrigo, E.; Filipuzzi, M.; Germanier, A.

    2014-08-01

    The use of radiation small fields, introduced by new techniques, can bring a considerable uncertainty in the precision of the acquired profiles, due to the conditions of lateral electronic non-equilibrium and the perturbations introduced by the detectors (volume effect and alteration of the charged particles flowing) [Das et al., 2007]. The development of new miniature detectors looks to diminish the uncertainty created by the material and the size of the sensitive volume of the dosimeter. For this reason, comparative measurements for three sizes of square field were carried out (20 mm, 10 mm and 5 mm, of side) using a detectors series: 3 ionization chambers (PTW-31003, IBA-CC04, PTW-31016), 2 diodes (PTW-60012, IBA-Sfd), thermoluminescent detectors micro-cubes of 1 mm of edge (TLD-700) and radiochromic s films EBT-3. These last two were used as reference detectors, due to their spatial high resolution and similar performance with Monte Carlo simulations [Francescon et al., 1998]. So much the thermoluminescent detectors as the radiochromic films resolved the profiles in a similar way. Both diodes responded correctly, but the rest of the detectors overestimated the gloom of the fields, which allows conclude that the used TLD (and both diodes) can resolve field sizes correctly, usually utilized in radio-surgery, without producing significant alterations in the acquired data. (author)

  3. Lateral vibration behavior analysis and TLD vibration absorption design of the soft yoke single-point mooring system

    Science.gov (United States)

    Lyu, Bai-cheng; Wu, Wen-hua; Yao, Wei-an; Du, Yu

    2017-06-01

    Mooring system is the key equipment of FPSO safe operation. The soft yoke mooring system is regarded as one of the best shallow water mooring strategies and widely applied to the oil exploitation in the Bohai Bay in China and the Gulf of Mexico. Based on the analysis of numerous monitoring data obtained by the prototype monitoring system of one FPSO in the Bohai Bay, the on-site lateral vibration behaviors found on the site of the soft yoke subject to wave load were analyzed. ADAMS simulation and model experiment were utilized to analyze the soft yoke lateral vibration and it was determined that lateral vibration was resonance behaviors caused by wave excitation. On the basis of the soft yoke longitudinal restoring force being guaranteed, a TLD-based vibration damper system was constructed and the vibration reduction experiments with multi-tank space and multi-load conditions were developed. The experimental results demonstrated that the proposed TLD vibration reduction system can effectively reduce lateral vibration of soft yoke structures.

  4. Glow-peak stability in 6LiF:Mg, Ti (TLD-600) exposed to a Fe-ion beam

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    2001-01-01

    The stability of glow peaks in 6 LiF:Mg, Ti (TLD-600) exposed to a high-energy Fe-ion beam was examined in comparison to 137 Cs γ-ray irradiation under changing annealing conditions. The peak areas induced by the Fe ions were much smaller than those by γ-rays. The sizes and positions of peaks 3-5 in Fe-ion irradiated samples were hardly changed after post-annealing at 100 deg C x 30 min, regardless of the pre-annealing conditions (fast quenching or subsequent pre-annealing at 100 deg C x 2 h). Whereas, the peaks in γ-ray irradiated samples were notably affected by post-annealing; the peak positions and peak-area sizes changed in different ways depending on the pre-annealing conditions. The effects of post-annealing on peak 6 were identical for Fe ions and γ-rays. These facts suggest that peaks 3-5 in TLD-600 comprised both stable and unstable luminescent centers, and that the latter part would be easily depleted in highly dense ionization. (author)

  5. Dosimetric evaluation of the response of the TLD-100 dosemeters in the IMRT technique by 'Step and Shoot'

    International Nuclear Information System (INIS)

    Vasquez, J.; Benavides, S.O.

    2005-01-01

    We show the results of the dosimetry response of LiF thermoluminescent crystals: TLD-100, where they were radiated in a linear accelerator Siemens Primus Hl using the Intensity Modulated Radiation Therapy (IMRT) by step and shoot technique. Previous to the crystals calibration and response evaluation, the acceptation procedures recommended by the TG-53 protocol for validation of the technique were carried out. The planning system utilized was the Theraplan Plus 3.8, using the algorithm of Pencil Kernel. The register and verification system was Lantis 5.2. The response curve of dose versus charge was obtained from the readings of the TLD in a Harshaw 3500. The crystals were radiated in a Bench- Marck phantom with doses previously determined by using ionization chambers for square radiation fields, in a beam with a 0.68 TPR20,10 corresponding to 6 MV of energy. We compare the response of these through of radiation of segmented fields in a Anthropomorphic phantom and the calculated doses by the planning system. The results obtained in the crystals response show deviations less than 5 % between the measured dose and the calculated dose in the zones of low gradient. It allows its implementation like routine control of quality by IMRT. (Author)

  6. Cliff : the automatized zipper

    NARCIS (Netherlands)

    Baharom, M.Z.; Toeters, M.J.; Delbressine, F.L.M.; Bangaru, C.; Feijs, L.M.G.

    2016-01-01

    It is our strong believe that fashion - more specifically apparel - can support us so much more in our daily life than it currently does. The Cliff project takes the opportunity to create a generic automatized zipper. It is a response to the struggle by elderly, people with physical disability, and

  7. Automatic Complexity Analysis

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    1989-01-01

    One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstract...

  8. Automatic Oscillating Turret.

    Science.gov (United States)

    1981-03-01

    Final Report: February 1978 ZAUTOMATIC OSCILLATING TURRET SYSTEM September 1980 * 6. PERFORMING 01G. REPORT NUMBER .J7. AUTHOR(S) S. CONTRACT OR GRANT...o....e.... *24 APPENDIX P-4 OSCILLATING BUMPER TURRET ...................... 25 A. DESCRIPTION 1. Turret Controls ...Other criteria requirements were: 1. Turret controls inside cab. 2. Automatic oscillation with fixed elevation to range from 20* below the horizontal to

  9. 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)

  10. Automatic sweep circuit

    International Nuclear Information System (INIS)

    Keefe, D.J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input is described. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found

  11. Automatic sweep circuit

    Science.gov (United States)

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  12. Recursive automatic classification algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, E V; Dorofeyuk, A A

    1982-03-01

    A variational statement of the automatic classification problem is given. The dependence of the form of the optimal partition surface on the form of the classification objective functional is investigated. A recursive algorithm is proposed for maximising a functional of reasonably general form. The convergence problem is analysed in connection with the proposed algorithm. 8 references.

  13. Automatic Commercial Permit Sets

    Energy Technology Data Exchange (ETDEWEB)

    Grana, Paul [Folsom Labs, Inc., San Francisco, CA (United States)

    2017-12-21

    Final report for Folsom Labs’ Solar Permit Generator project, which has successfully completed, resulting in the development and commercialization of a software toolkit within the cloud-based HelioScope software environment that enables solar engineers to automatically generate and manage draft documents for permit submission.

  14. Examining College Students’ Reading Behaviors and Needs for Ebook Readers

    Directory of Open Access Journals (Sweden)

    Wei-Jane Lin

    2012-12-01

    Full Text Available This study investigates college students’ reading behaviors and attitudes toward print and electronic carriers of books. With the prosperity and variety of ebook readers currently, it is important to understand the genuine needs of the users to better leverage the features and functions of the ebook readers. The methodology of survey research is conducted to explore 76 undergraduate students’ experiences, preferences and appraisals toward reading via the print books and ebook readers. Generally the college students possess positive attitudes toward and are willing to take advantage of the ebook and ebook reader services provided by libraries, but the current rate of use is low. The results suggested that student adoption of ebook readers are affected by their goals of reading. The college students prefer ebook readers significantly for leisure reading, and highly demand the functionality of multimedia presentations and file management. When reading academic contexts, the college students preferred hardcovers and online ebooks via the Web browser, and they value the functions of searching, marking and file management on ebook readers especially. [Article content in Chinese

  15. Semantic and phonological coding in poor and normal readers.

    Science.gov (United States)

    Vellutino, F R; Scanlon, D M; Spearing, D

    1995-02-01

    Three studies were conducted evaluating semantic and phonological coding deficits as alternative explanations of reading disability. In the first study, poor and normal readers in second and sixth grade were compared on various tests evaluating semantic development as well as on tests evaluating rapid naming and pseudoword decoding as independent measures of phonological coding ability. In a second study, the same subjects were given verbal memory and visual-verbal learning tasks using high and low meaning words as verbal stimuli and Chinese ideographs as visual stimuli. On the semantic tasks, poor readers performed below the level of the normal readers only at the sixth grade level, but, on the rapid naming and pseudoword learning tasks, they performed below the normal readers at the second as well as at the sixth grade level. On both the verbal memory and visual-verbal learning tasks, performance in poor readers approximated that of normal readers when the word stimuli were high in meaning but not when they were low in meaning. These patterns were essentially replicated in a third study that used some of the same semantic and phonological measures used in the first experiment, and verbal memory and visual-verbal learning tasks that employed word lists and visual stimuli (novel alphabetic characters) that more closely approximated those used in learning to read. It was concluded that semantic coding deficits are an unlikely cause of reading difficulties in most poor readers at the beginning stages of reading skills acquisition, but accrue as a consequence of prolonged reading difficulties in older readers. It was also concluded that phonological coding deficits are a probable cause of reading difficulties in most poor readers.

  16. E-Books on the Mobile E-Reader

    Directory of Open Access Journals (Sweden)

    Chulyun Kim

    2013-01-01

    Full Text Available The market for e-books has been established during the past several years. Many e-book readers are commercially available, and millions of e-book titles are available for purchase or free download. E-paper technology has matured enough to be used as the screen for dedicated e-book readers which make reading possible with the familiar feel of reading printed books. In this paper, we provide a comprehensive review of the status of the e-book, including the architecture and features of e-book readers, market adoption and e-book industry ecosystem.

  17. Journal of Clipped Words in Reader's Digest Magazine

    OpenAIRE

    Simanjuntak, Lestari

    2012-01-01

    This study deals with Clipped Words in the “Laughter, the Best Medicine” of Reader's Digest. The objectives of the study are to find out the types of clipped words which are used in the “Laughter, the Best Medicine” of Reader's Digest, to find out sthe dominantly used in the whole story and to reason the dominant clipped word use in the text. The study use descriptive qualitative method. The data were collected from seventeen selected Reader's Digest which contains the clipped word by applie...

  18. Usability and Accessibility of eBay by Screen Reader

    Science.gov (United States)

    Buzzi, Maria Claudia; Buzzi, Marina; Leporini, Barbara; Akhter, Fahim

    The evolution of Information and Communication Technology and the rapid growth of the Internet have fuelled a great diffusion of eCommerce websites. Usually these sites have complex layouts crowded with active elements, and thus are difficult to navigate via screen reader. Interactive environments should be properly designed and delivered to everyone, including the blind, who usually use screen readers to interact with their computers. In this paper we investigate the interaction of blind users with eBay, a popular eCommerce website, and discuss how using the W3C Accessible Rich Internet Applications (WAI-ARIA) suite could improve the user experience when navigating via screen reader.

  19. Power Efficient Gurumukhi Unicode Reader Design and Implementation on FPGA

    DEFF Research Database (Denmark)

    Kaur, Amanpreet; Singh, Sunny; Pandey, Bishwajeet

    2017-01-01

    Gurumukhi is found to be the most widely used language of Pakistan, and it is ranked 3rd in Canada, 7th in India and almost 4th most spoken language in U.K. This Unicode Reader is cost effective solution for learning as well as understanding the Punjabi language by the people across the globe .This...... reader helps the user to understand, whether written text is consonants, vowels or digits of Gurumukhi scripts. This paper can also be the solution to the various problems occurred in research of Punjabi natural language processing. Hardware is designed for Gurumukhi Unicode Reader (GUR...

  20. Entropy based quantification of Ki-67 positive cell images and its evaluation by a reader study

    Science.gov (United States)

    Niazi, M. Khalid Khan; Pennell, Michael; Elkins, Camille; Hemminger, Jessica; Jin, Ming; Kirby, Sean; Kurt, Habibe; Miller, Barrie; Plocharczyk, Elizabeth; Roth, Rachel; Ziegler, Rebecca; Shana'ah, Arwa; Racke, Fred; Lozanski, Gerard; Gurcan, Metin N.

    2013-03-01

    Presence of Ki-67, a nuclear protein, is typically used to measure cell proliferation. The quantification of the Ki-67 proliferation index is performed visually by the pathologist; however, this is subject to inter- and intra-reader variability. Automated techniques utilizing digital image analysis by computers have emerged. The large variations in specimen preparation, staining, and imaging as well as true biological heterogeneity of tumor tissue often results in variable intensities in Ki-67 stained images. These variations affect the performance of currently developed methods. To optimize the segmentation of Ki-67 stained cells, one should define a data dependent transformation that will account for these color variations instead of defining a fixed linear transformation to separate different hues. To address these issues in images of tissue stained with Ki-67, we propose a methodology that exploits the intrinsic properties of CIE L∗a∗b∗ color space to translate this complex problem into an automatic entropy based thresholding problem. The developed method was evaluated through two reader studies with pathology residents and expert hematopathologists. Agreement between the proposed method and the expert pathologists was good (CCC = 0.80).

  1. Development of portable ESR spectrometer as a reader for alanine dosimeters

    International Nuclear Information System (INIS)

    Kojima, T.; Haruyama, Y.; Tachibana, H.; Tanaka, R.; Okamoto, J.

    1993-01-01

    A prototype portable electron spin resonance (ESR) spectrometer was designed and tested, and its feasibility as a reader of alanine dosimeters was studied from the two standpoints of reproducibility of readings and sensitivity sufficient for dosimetry in the absorbed dose range 1-100 kGy. It has two main components: a permanent magnet and resonator; and a unit box with a microwave and auto-frequency control (AFC) circuit, a sweep controller of magnetic field, display, etc. In the present preliminary study, reproducibility values are measured with the same ESR parameters and alanine-polystyrene (alanine-PS) dosimeter at a dose of 1 kGy: repeatedly measuring without removing dosimeter from the cavity; individual measurement with removing and inserting again into the cavity with readjustment of ESR parameters. Alanine/ESR dosimetry using this spectrometer has a measurable dose range from 1 to 100 kGy with relatively high precision within ± 3% (1σ) as a preliminary result. The portable ESR spectrometer may also be modified as an automatic, more precise, dedicated alanine dosimeter reader. (author)

  2. Automatic indexing, compiling and classification

    International Nuclear Information System (INIS)

    Andreewsky, Alexandre; Fluhr, Christian.

    1975-06-01

    A review of the principles of automatic indexing, is followed by a comparison and summing-up of work by the authors and by a Soviet staff from the Moscou INFORM-ELECTRO Institute. The mathematical and linguistic problems of the automatic building of thesaurus and automatic classification are examined [fr

  3. Determination of the dose in eyes lens by TLD, in PET/CT by technicians in PET/CT service; Determinacion de la dosis en cristalino por medio de TLD, en personal tecnico de servicio PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Emiliano A., E-mail: eam.marino@gmail.com [Universidad Nacional de Cuyo (UNC), Rio Negro (Argentina). Instituto Balseiro; Arenas, German M. [Fundacion Escuela de Medicina Nuclear (FUESMEN), Mendoza (Argentina)

    2013-11-01

    This work was supported, on the one hand, in a part of the project ORAMED which consisted of a design of a TLD dosimeter for measurements of Hp (3) in areas close to the lens, for interventional radiology physicians. On the other hand, Berhens work proposes using calibrated TLDs Hp (0.07) and Hp (10) to estimate Hp (3) crystal. This resulted in dosimeters calibrated using Hp (10) slab, and mount them on glasses, to estimate the dose to the lens of the technical staff of the Service PET / CT. The value obtained 29mSv/year of Lens Dose Equivalent exceeds the recommended limit. We also demonstrate that, under the current working conditions, the values of Hp (3) reported from whole body dosimeter does not represent faithfully the lens dose.

  4. Response of TLD-100 LiF dosimeters for X-rays of low energies; Respuesta de dosimetros de TLD-100 de LiF para rayos X de bajas energias

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, X5016LEA Cordoba (Argentina)

    2011-10-15

    In diverse practical applications as the existent in radiological clinics, industrial facilities and research laboratories, the solid state dosimeters are used for the measure of the different types of ionizing radiations. At the present time dosimeters are manufactured with different types of materials that present thermoluminescent properties, to the effects of determining the absorbed radiation dose. Under these conditions, the radiation dose is determined integrated in all the range of energies of the beam of X-rays, since it assumes that the response of these dosimeters is lineal with the energy of the photons or radiant particles. Because interest exists in advancing in the development of a determination method in the way of the X-rays spectrum emitted by a tube of those used in diagnostic or therapy, we have measured the response of TLD-100 LiF dosimeters for low energies, minor at 60 keV, for a several group of these dosimeters. (Author)

  5. Thermoluminescence of pure LiF and Lif (TLD-100) irradiated at room temperature; Termoluminiscencia en LiF puro y LiF dosimetrico (TLD-100), irradiados a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Sagastibelza Chivite, F

    1980-07-01

    The thermoluminescence of pure LiF and LiF (TLD-100) crystals irradiated at room temperature with x - or gamma-rays has been studied up to 460 degree centigree. For most of the glow peaks found the kinetics, preexponential factors and activation energies have been determined. These parameters have been obtained by means of the isothermal method. The study of the thermal annealing of the radiation induced F and Z centres has allow to show that there is a correlation among the glow peaks and the annealing stages of these centres. It is concluded that the F and Z - centres play the role of recombination centres for halogen interstitial atom thermally released from traps. Light emission occurs in this recombination. (Author) 120 refs.

  6. Metal filters for the compensation of photon energy dependence of the response of CaSO4: Dy - Teflon TLD Discs

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Bhatt, R.C.

    1979-01-01

    Metal filters of aluminium, stainless steel, copper, cadmium, tin and lead were studied for compensation of the photon energy dependence of the response of CaSO 4 : Dy Teflon TLD Discs. It was found that metals such as cadmium and tin (which are normally used for this purpose) with their K absorption edges around 30 keV, are poor compensators of photon energy dependence. However, if either cadmium or tin is used in combination with either copper or stainless steel (with the lower Z filter nearer to the TLD dosimeter disc) a better compensation of photon energy dependence is achieved. Consequently, for personnel monitoring of X and gamma radiations, a TLD badge with CaSO 4 : Dy Teflon TLD discs and two sets of combination filters has been recommended. In the range of 27 keV -1.25 MeV this badge offers a photon energy response which varies within +-15%. This is a considerable improvement on the corresponding limits of +-65% on using a single filter. (orig.)

  7. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study

    NARCIS (Netherlands)

    Koivisto, J.; Schulze, D.; Wolff, J.E.H.; Rottke, D.

    2014-01-01

    Objectives: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Methods: Organ and effective

  8. How Readers and Advertisers Benefit from Local Newspaper Competition.

    Science.gov (United States)

    Everett, Shu-Ling Chen; Everett, Stephen E.

    1989-01-01

    Explores relations among three competitive schemes with respect to newspapers' price structures, including advertising rates and prices to consumers. Finds that readers get some benefit from greater competition, but that advertisers do not. (MM)

  9. 21 CFR 866.2850 - Automated zone reader.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2850 Automated zone reader... surface of certain culture media used in disc-agar diffusion antimicrobial susceptibility tests. The...

  10. An Interview with Crosby Bonsall: A Writer for Beginning Readers.

    Science.gov (United States)

    Cox, Carole

    1985-01-01

    Crosby Bonsall, a prolific author-illustrator for young readers, comments on many topics related to writing, illustrating, and young children's initial independent encounters with print in books. (HOD)

  11. the management of writer-reader interaction in newspaper editorials

    African Journals Online (AJOL)

    Ntsane

    how dialogically expansive and contractive resources are used in this respect in editorials from different ... adopts a particular position and how they interact with potential readers. Engagement ..... An introductory tour through Appraisal Theory.

  12. Automatization of welding

    International Nuclear Information System (INIS)

    Iwabuchi, Masashi; Tomita, Jinji; Nishihara, Katsunori.

    1978-01-01

    Automatization of welding is one of the effective measures for securing high degree of quality of nuclear power equipment, as well as for correspondence to the environment at the site of plant. As the latest ones of the automatic welders practically used for welding of nuclear power apparatuses in factories of Toshiba and IHI, those for pipes and lining tanks are described here. The pipe welder performs the battering welding on the inside of pipe end as the so-called IGSCC countermeasure and the succeeding butt welding through the same controller. The lining tank welder is able to perform simultaneous welding of two parallel weld lines on a large thin plate lining tank. Both types of the welders are demonstrating excellent performance at the shops as well as at the plant site. (author)

  13. Automatic structural scene digitalization.

    Science.gov (United States)

    Tang, Rui; Wang, Yuhan; Cosker, Darren; Li, Wenbin

    2017-01-01

    In this paper, we present an automatic system for the analysis and labeling of structural scenes, floor plan drawings in Computer-aided Design (CAD) format. The proposed system applies a fusion strategy to detect and recognize various components of CAD floor plans, such as walls, doors, windows and other ambiguous assets. Technically, a general rule-based filter parsing method is fist adopted to extract effective information from the original floor plan. Then, an image-processing based recovery method is employed to correct information extracted in the first step. Our proposed method is fully automatic and real-time. Such analysis system provides high accuracy and is also evaluated on a public website that, on average, archives more than ten thousands effective uses per day and reaches a relatively high satisfaction rate.

  14. Automatic trend estimation

    CERN Document Server

    Vamos¸, C˘alin

    2013-01-01

    Our book introduces a method to evaluate the accuracy of trend estimation algorithms under conditions similar to those encountered in real time series processing. This method is based on Monte Carlo experiments with artificial time series numerically generated by an original algorithm. The second part of the book contains several automatic algorithms for trend estimation and time series partitioning. The source codes of the computer programs implementing these original automatic algorithms are given in the appendix and will be freely available on the web. The book contains clear statement of the conditions and the approximations under which the algorithms work, as well as the proper interpretation of their results. We illustrate the functioning of the analyzed algorithms by processing time series from astrophysics, finance, biophysics, and paleoclimatology. The numerical experiment method extensively used in our book is already in common use in computational and statistical physics.

  15. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of peaks of high temperature in TLD-100 dosemeters; Eficiencias termoluminiscentes relativas proton/gamma y helio/gamma de picos de alta temperatura en dosimetros TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Flores M, E. [UNAM, Facultad de Ciencias, 04510 Mexico D.F. (Mexico)

    2007-07-01

    The increase of the applications of ion beams in radiotherapy treatments has generated interest in the study of the thermoluminescent materials (TL) that allow to determine the applied doses. A way to quantify the TL response from these materials to ions is by means of the relative thermoluminescent efficiency. In the group of Thermoluminescent dosimetry of the Institute of Physics of the UNAM (IFUNAM) the thermoluminescent response of the TLD-100 dosemeters has been studied, which present a glow curve characteristic with several peaks that correspond to traps and luminescent centers in the material. The stable peaks know each other as 4, 5, 6a, 6b, 7, 8, 9 and 10. The efficiencies should be measured using the response so much to the radiation of interest (in this case protons and helium ions) as the response to gamma radiation. In previous works with ions of low energy taken place in the Pelletron accelerator of the IFUNAM was only measured the TL efficiency for the peak 5 and the total signal. It had not been possible to measure the efficiency of the peaks of high temperature (6a-10) because, for the gamma radiation, the peaks of high temperature show very small signals; however, recently Massillon carries out measures of efficiency TL of peaks of high temperature for ions of intermediate energy using a protocol special of reading and of deconvolution that allows to measure the signals coming from the peaks of high temperature. In this work is implemented this same protocol to complete the study of TL efficiencies at low energy of protons and helium and to determine if the values of efficiency depend on the used reading protocol. For it is reported it measures of the relative efficiency of the peaks of high temperature from the TLD-100 exposed to protons of 1.5 MeV and nuclei of helium of 3 and 7.5 MeV. (Author)

  16. Measure of the attenuation curve of a beam of X-rays with TLD-100 dosimeters of LiF; Medicion de la curva de atenuacion de un haz de rayos X con dosimetros TLD-100 de LiF

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, Cordoba (Argentina); Germanier, A. [Ministerio de Ciencia y Tecnologia, Ceprocor, Unidad de Estudios Fisicos, Alvarez de Arenas 230, X5004AAP Barrio Juniors, Cordoba (Argentina); Delgado, V. [Universidad Complutense de Madrid, Departamento de Fisica Medica, Ciudad Universitaria, 28040 Madrid (Spain)

    2011-10-15

    The attenuation curve of a beam of X-rays represents the beam intensity in function of the attenuator thickness interposed between the source and the detector. To know with the major possible precision the attenuation curve is indispensable in procedures of spectral reconstruction. Their periodic measuring also offers valuable information on the correct operation of a tube of X-rays, diagnostic or therapy, when not have a specific detector for that activity. In this work was measured the attenuation curve of a tube of X-rays operated to 50 kV and 0.5 ma, using existent elements in any diagnostic or therapy laboratory with radiations. In the measures commercial aluminum foil was used, bent until 24 times and thermoluminescent dosimeters TLD 100 - LiF. Also, for comparison, was measured this attenuation curve with an ionization chamber brand Capintec model 192. Was determined by X-rays fluorescence the composition of the aluminium foil, since the present elements in the alloy can to affect the form of the attenuation curve. It is interesting to observe that these elements are in very low proportion (ppm) that they do not alter the attenuation capacity of the pure aluminium. Finally in a precision balance we weigh a big piece (30 cm x 100 cm) of aluminium foil and we obtained the thickness in g/c m2. It is possible to obtain attenuation curves of a beam of X-rays, with a high precision procedure and reproducibility. The use of TLD-100 dosimeters of LiF or similar makes that this activity was also quick and simple. (Author)

  17. Randomized algorithms in automatic control and data mining

    CERN Document Server

    Granichin, Oleg; Toledano-Kitai, Dvora

    2015-01-01

    In the fields of data mining and control, the huge amount of unstructured data and the presence of uncertainty in system descriptions have always been critical issues. The book Randomized Algorithms in Automatic Control and Data Mining introduces the readers to the fundamentals of randomized algorithm applications in data mining (especially clustering) and in automatic control synthesis. The methods proposed in this book guarantee that the computational complexity of classical algorithms and the conservativeness of standard robust control techniques will be reduced. It is shown that when a problem requires "brute force" in selecting among options, algorithms based on random selection of alternatives offer good results with certain probability for a restricted time and significantly reduce the volume of operations.

  18. Automatic food decisions

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    Consumers' food decisions are to a large extent shaped by automatic processes, which are either internally directed through learned habits and routines or externally influenced by context factors and visual information triggers. Innovative research methods such as eye tracking, choice experiments...... and food diaries allow us to better understand the impact of unconscious processes on consumers' food choices. Simone Mueller Loose will provide an overview of recent research insights into the effects of habit and context on consumers' food choices....

  19. Automatic LOD selection

    OpenAIRE

    Forsman, Isabelle

    2017-01-01

    In this paper a method to automatically generate transition distances for LOD, improving image stability and performance is presented. Three different methods were tested all measuring the change between two level of details using the spatial frequency. The methods were implemented as an optional pre-processing step in order to determine the transition distances from multiple view directions. During run-time both view direction based selection and the furthest distance for each direction was ...

  20. LESS SKILLED READERS HAVE LESS EFFICIENT SUPPRESSION MECHANISMS

    OpenAIRE

    Gernsbacher, Morton Ann

    1993-01-01

    One approach to understanding the component processes and mechanisms underlying adult reading skill is to compare the performance of more skilled and less skilled readers on laboratory experiments. The results of some recent experiments employing this approach demonstrate that less skilled adult readers suppress less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meanings of spade), the incorrect forms of homophones (e.g., patients vs. patien...

  1. Making a Commitment to Strategic-Reader Training

    Institute of Scientific and Technical Information of China (English)

    FREDRICKA L. STOLLER; REIKO KOMIYAMA

    2013-01-01

    Skilled readers by definition are strategic; they are able to use a repertoire of reading strategies , flexibly and in meaningful combinations , to achieve their reading comprehension goals . Thus , one of the aims of foreign and second language (L2) reading curricula should be to move students toward becoming more strategic readers . This curricular orientation can be best achieved when a strong commitment is made to strategic-reader training as a regular and consistent component of instruction across the curriculum . To explore this stance , we examine the reading strategies used by skilled readers , contrast teaching strategies with training strategic readers ( i .e . , strategic-reader training) , and examine five strategic-reader training approaches from first language contexts that can be adapted by L2 professionals to enhance the reading instruction offered in their L 2 classes . The five approaches targeted for exploration include Directed Reading-Thinking Activity , Reciprocal Teaching , Transactional Strategies Instruction , Questioning the Author , and Concept-Oriented Reading Instruction . Though distinct from one another , they all acknowledge the importance of explicit explanations about strategies (or reminders about the use of select strategies) , teacher modeling , scaffolded tasks , active student engagement , student practice , classroom discussions of strategy use , and the gradual release of responsibility to students who eventually decide for themselves (and/or with peers) when , where , and why to use which strategies to achieve their comprehension goals . We conclude with a discussion of the challenges , and suggestions for overcoming them , that L 2 teachers and students often face in making a commitment to strategic-reader training .

  2. Flexible electronics enters the e-reader market

    Science.gov (United States)

    Banks, Michael

    2010-02-01

    A company that was spun off from the physics department at the University of Cambridge in the UK 10 years ago released its first product last month. Plastic Logic, founded by Henning Sirringhaus and Richard Friend, launched an electronic reader that can display books, magazines and newspapers on a flexible, lightweight plastic display. The reader commercializes pioneering work first started over 20 years ago at the lab by the two physicists, who are based in the department's optoelectronics group.

  3. Inferential processes in readers with Down syndrome

    Directory of Open Access Journals (Sweden)

    Rosende-Vázquez, Marta

    2013-03-01

    Full Text Available The aim of this work is to know if the source of the difficulty in making inferences, readers with Down syndrome, is in access to prior knowledge or constructing ideas from purely textual knowledge (based on Saldaña and Frith, 2002 for autism. Involved a sample of 20 students with Down syndrome and mild mental retardation (mean IQ = 60 and a control group of 20 children without cognitive deficits. They were matched as to their extent read metal age via Prueba de Evaluación del Retraso Lector (average 8 years. We created two experimental situations: a subjects had to generate inferences based on physical knowledge, b social inferences about knowledge. The ability to check and reaction times in the activation of inferences about physical and social knowledge. We also analyzed the influence that the effect "priming". Results showed: a a rate of correct inferences similar verification tasks between the two groups, b Down subjects take longer to access knowledge that the previous text, c reaction times used by subjects Down were higher in activating physical inferences, d there were no significant differences in the population without reaction times gap between physical and social inferences e subjects without deficits benefited effect "priming" in both types of inferences f Down subjects only improve reaction time in the inferences of social nature. El presente estudio pretende conocer si el origen de la dificultad para realizar inferencias, en lectores con Síndrome de Down, se encuentra en el acceso al conocimiento previo o en la construcción de ideas a partir del conocimiento puramente textual (basándonos en Saldaña y Frith, 2002 para autismo. Participó una muestra de 20 alumnos con Síndrome de Down y discapacidad mental leve (media de C.I.= 60 y un grupo control de 20 alumnos sin déficit cognitivo. Ambos fueron igualados en cuanto a su edad mental lectora medida a través de la Prueba de Evaluación del Retraso Lector (media 8 a

  4. Networks of reader and country status: an analysis of Mendeley reader statistics

    Directory of Open Access Journals (Sweden)

    Robin Haunschild

    2015-11-01

    Full Text Available The number of papers published in journals indexed by the Web of Science core collection is steadily increasing. In recent years, nearly two million new papers were published each year; somewhat more than one million papers when primary research papers are considered only (articles and reviews are the document types where primary research is usually reported or reviewed. However, who reads these papers? More precisely, which groups of researchers from which (self-assigned scientific disciplines and countries are reading these papers? Is it possible to visualize readership patterns for certain countries, scientific disciplines, or academic status groups? One popular method to answer these questions is a network analysis. In this study, we analyze Mendeley readership data of a set of 1,133,224 articles and 64,960 reviews with publication year 2012 to generate three different networks: (1 The network based on disciplinary affiliations of Mendeley readers contains four groups: (i biology, (ii social sciences and humanities (including relevant computer sciences, (iii bio-medical sciences, and (iv natural sciences and engineering. In all four groups, the category with the addition “miscellaneous” prevails. (2 The network of co-readers in terms of professional status shows that a common interest in papers is mainly shared among PhD students, Master’s students, and postdocs. (3 The country network focusses on global readership patterns: a group of 53 nations is identified as core to the scientific enterprise, including Russia and China as well as two thirds of the OECD (Organisation for Economic Co-operation and Development countries.

  5. The personnel dosimetry record keeping system at AEE Winfrith

    International Nuclear Information System (INIS)

    Gill, D.W.

    1979-09-01

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

  6. An IoT Reader for Wireless Passive Electromagnetic Sensors.

    Science.gov (United States)

    Galindo-Romera, Gabriel; Carnerero-Cano, Javier; Martínez-Martínez, José Juan; Herraiz-Martínez, Francisco Javier

    2017-03-28

    In the last years, many passive electromagnetic sensors have been reported. Some of these sensors are used for measuring harmful substances. Moreover, the response of these sensors is usually obtained with laboratory equipment. This approach highly increases the total cost and complexity of the sensing system. In this work, a novel low-cost and portable Internet-of-Things (IoT) reader for passive wireless electromagnetic sensors is proposed. The reader is used to interrogate the sensors within a short-range wireless link avoiding the direct contact with the substances under test. The IoT functionalities of the reader allows remote sensing from computers and handheld devices. For that purpose, the proposed design is based on four functional layers: the radiating layer, the RF interface, the IoT mini-computer and the power unit. In this paper a demonstrator of the proposed reader is designed and manufactured. The demonstrator shows, through the remote measurement of different substances, that the proposed system can estimate the dielectric permittivity. It has been demonstrated that a linear approximation with a small error can be extracted from the reader measurements. It is remarkable that the proposed reader can be used with other type of electromagnetic sensors, which transduce the magnitude variations in the frequency domain.

  7. Use of lead aprons - further considerations of estimation of doses and conditions of acute exposures of TLD badge in diagnostic x-ray institutions

    International Nuclear Information System (INIS)

    Pradhan, A.S.; Chatterjee, S.

    2003-01-01

    In the recent study the authors reported that the exposure conditions of the use of the TLD badge, whether worn under or over the lead apron could be estimated from the readout of the TLD badge used in X-ray diagnostic departments. The effectiveness of lead aprons procured from different suppliers having the same value of quoted nominal lead equivalence was found to vary severely and this indicated some limitation in the applicability of the method of evaluation of exposure conditions of the badge. The transmission factors for the lead aprons varied up to a factor of 15 for the same value of quoted nominal lead equivalence procured from three different suppliers. This is of serious consequences in radiation protection and attracts attention for quality control. An error in the estimation of the exposure conditions of the TLD badge could lead to an underestimation of doses up to 4 times using the prevalent method. The estimation of the actual doses of radiation workers in the cases of over-exposures for the situations of the use of the TLD badge over the lead apron showed that the variation in the quality of lead aprons could be wrong in the range from 1.6 to 25 times even if the kVp of the machine is exactly known. Therefore, attempt should not be made to estimate the actual doses under lead apron from the readout of the TLD badge worn over the apron, as the real values of the transmission factors of the aprons and kVp of the X-ray machine may not be available. (author)

  8. Quality Assurance in Individual Monitoring: 10 Years of Performance Monitoring of the TLD Based TNO Individual Monitoring Service (invited paper)

    International Nuclear Information System (INIS)

    Dijk, J.W.E. van

    1998-01-01

    The QA subscription forms the nucleus of the Quality Assurance (QA) programme of the TLD-based Individual Monitoring Service of TNO-CSD. This QA subscription is the subscription of a dummy customer to the service. As this customer is treated exactly like a normal customer, all aspects of the service are monitored by the QA subscription. An overview is given of 10 years of monitoring the performance of the service. Various improvements over the past decade have resulted in a standard deviation in a low dose measurement of 0.01 mSv and a relative standard deviation at higher doses of 5%. These figures represent the performance under routine circumstances and thus include variations due to variations in the natural background from place to place and, for example, due to transport. (author)

  9. Determination of the dose in eyes lens by TLD, in PET/CT by technicians in PET/CT service

    International Nuclear Information System (INIS)

    Marino, Emiliano A.

    2013-01-01

    This work was supported, on the one hand, in a part of the project ORAMED which consisted of a design of a TLD dosimeter for measurements of Hp (3) in areas close to the lens, for interventional radiology physicians. On the other hand, Berhens work proposes using calibrated TLDs Hp (0.07) and Hp (10) to estimate Hp (3) crystal. This resulted in dosimeters calibrated using Hp (10) slab, and mount them on glasses, to estimate the dose to the lens of the technical staff of the Service PET / CT. The value obtained 29mSv/year of Lens Dose Equivalent exceeds the recommended limit. We also demonstrate that, under the current working conditions, the values of Hp (3) reported from whole body dosimeter does not represent faithfully the lens dose

  10. Quality Assurance in Individual Monitoring: 10 Years of Performance Monitoring of the TLD Based TNO Individual Monitoring Service (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, J.W.E. van

    1998-07-01

    The QA subscription forms the nucleus of the Quality Assurance (QA) programme of the TLD-based Individual Monitoring Service of TNO-CSD. This QA subscription is the subscription of a dummy customer to the service. As this customer is treated exactly like a normal customer, all aspects of the service are monitored by the QA subscription. An overview is given of 10 years of monitoring the performance of the service. Various improvements over the past decade have resulted in a standard deviation in a low dose measurement of 0.01 mSv and a relative standard deviation at higher doses of 5%. These figures represent the performance under routine circumstances and thus include variations due to variations in the natural background from place to place and, for example, due to transport. (author)

  11. On the effect of updated MCNP photon cross section data on the simulated response of the HPA TLD.

    Science.gov (United States)

    Eakins, Jonathan

    2009-02-01

    The relative response of the new Health Protection Agency thermoluminescence dosimeter (TLD) has been calculated for Narrow Series X-ray distribution and (137)Cs photon sources using the Monte Carlo code MCNP5, and the results compared with those obtained during its design stage using the predecessor code, MCNP4c2. The results agreed at intermediate energies (approximately 0.1 MeV to (137)Cs), but differed at low energies (<0.1 MeV) by up to approximately 10%. This disparity has been ascribed to differences in the default photon interaction data used by the two codes, and derives ultimately from the effect on absorbed dose of the recent updates to the photoelectric cross sections. The sources of these data have been reviewed.

  12. Beta response of CaSO4:Dy based TLD badge and its angular dependence studies for personnel monitoring applications

    International Nuclear Information System (INIS)

    Kumar, Munish; Rakesh, R.B.; Sneha, C.; Ratna, P.; Bakshi, A.K.; Datta, D.

    2016-01-01

    In India, shallow/skin doses received by radiation workers from beta particles are measured using CaSO 4 :Dy based Teflon embedded TLD badge. The beta particles having maximum energy E max > 0.6 MeV - ≥ 3.54 MeV are monitored. The ratio of the response of discs under open and plastic regions (D Open/ D Perspex ) is used to estimate the energy of the beta source and to apply response correction factor. This is required as the disc dosimeters are thick and exhibit energy dependent response. Due to lack of comprehensive information regarding disc ratios and associated beta multiplication/response correction factors, present study was performed

  13. The use of TLD-700H dosemeters in the assessment of external doses at the former Semipalatinsk nuclear test site.

    Science.gov (United States)

    Hill, P; Dederichs, H; Pillath, J; Schlecht, W; Hille, R; Artemev, O; Ptitskaya, L; Akhmetov, M

    2002-01-01

    The joint projects performed since 1995 by the Jülich Research Centre in co-operation with the Kazakh National Nuclear Centre in the area of the former nuclear test site near Semipalatinsk, in eastern Kazakhstan, have assessed the current dose rate of the population at and around the test site, as well as determining retrospectively the dose rate of persons affected by the atmospheric tests. Measurements of the population by personal dosemeters depend on reliably wearing these dosemeters over prolonged periods of time, and of a sufficient dosemeter return. In the past, such measurements have been particularly successful whenever short wearing times were possible. This requires high sensitivity of the dosemeters. The suitability of the highly sensitive TLD material of the BICRON TLD 700H type for such personal dosimetry measurements was investigated. It was tested in practical field application at the Semipalatinsk nuclear test site in September 2000. Initial results are available from individual doses received by a group of geologists and a group of herdsmen at the test site. For the first time, the individual dose was measured directly in these population groups. Detection limits below 1 microSv permit informative measurements for wearing times of less than two weeks. Most individual doses did not arise significantly out of local fluctuations of natural background. A conservative assessment from the aspect of practical health physics yielded a mean personal dose of 0.55 microSv per day for the herdsmen, whereas the geologists received a mean personal dose of 0.45 microSv per day. For an annual exposure period of typically, about three months, the radiation dose received by the persons investigated, in addition to the natural radiation exposure, is thus well below the international limit value of 1 mSv x a(-1) for the population dose.

  14. Measure of the attenuation curve of a beam of X-rays with TLD-100 dosimeters of LiF

    International Nuclear Information System (INIS)

    Bonzi, E. V.; Mainardi, R. T.; Germanier, A.; Delgado, V.

    2011-10-01

    The attenuation curve of a beam of X-rays represents the beam intensity in function of the attenuator thickness interposed between the source and the detector. To know with the major possible precision the attenuation curve is indispensable in procedures of spectral reconstruction. Their periodic measuring also offers valuable information on the correct operation of a tube of X-rays, diagnostic or therapy, when not have a specific detector for that activity. In this work was measured the attenuation curve of a tube of X-rays operated to 50 kV and 0.5 ma, using existent elements in any diagnostic or therapy laboratory with radiations. In the measures commercial aluminum foil was used, bent until 24 times and thermoluminescent dosimeters TLD 100 - LiF. Also, for comparison, was measured this attenuation curve with an ionization chamber brand Capintec model 192. Was determined by X-rays fluorescence the composition of the aluminium foil, since the present elements in the alloy can to affect the form of the attenuation curve. It is interesting to observe that these elements are in very low proportion (ppm) that they do not alter the attenuation capacity of the pure aluminium. Finally in a precision balance we weigh a big piece (30 cm x 100 cm) of aluminium foil and we obtained the thickness in g/c m2. It is possible to obtain attenuation curves of a beam of X-rays, with a high precision procedure and reproducibility. The use of TLD-100 dosimeters of LiF or similar makes that this activity was also quick and simple. (Author)

  15. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of peaks of high temperature in TLD-100 dosemeters

    International Nuclear Information System (INIS)

    Flores M, E.

    2007-01-01

    The increase of the applications of ion beams in radiotherapy treatments has generated interest in the study of the thermoluminescent materials (TL) that allow to determine the applied doses. A way to quantify the TL response from these materials to ions is by means of the relative thermoluminescent efficiency. In the group of Thermoluminescent dosimetry of the Institute of Physics of the UNAM (IFUNAM) the thermoluminescent response of the TLD-100 dosemeters has been studied, which present a glow curve characteristic with several peaks that correspond to traps and luminescent centers in the material. The stable peaks know each other as 4, 5, 6a, 6b, 7, 8, 9 and 10. The efficiencies should be measured using the response so much to the radiation of interest (in this case protons and helium ions) as the response to gamma radiation. In previous works with ions of low energy taken place in the Pelletron accelerator of the IFUNAM was only measured the TL efficiency for the peak 5 and the total signal. It had not been possible to measure the efficiency of the peaks of high temperature (6a-10) because, for the gamma radiation, the peaks of high temperature show very small signals; however, recently Massillon carries out measures of efficiency TL of peaks of high temperature for ions of intermediate energy using a protocol special of reading and of deconvolution that allows to measure the signals coming from the peaks of high temperature. In this work is implemented this same protocol to complete the study of TL efficiencies at low energy of protons and helium and to determine if the values of efficiency depend on the used reading protocol. For it is reported it measures of the relative efficiency of the peaks of high temperature from the TLD-100 exposed to protons of 1.5 MeV and nuclei of helium of 3 and 7.5 MeV. (Author)

  16. Measurement of residual radioactive surface contamination by 2-D laser heated TLD

    International Nuclear Information System (INIS)

    Jones, S.C.

    1997-06-01

    The feasibility of applying and adapting a two-dimensional laser heated thermoluminescence dosimetry system to the problem of surveying for radioactive surface contamination was studied. The system consists of a CO 2 laser-based reader and monolithic arrays of thin dosimeter elements. The arrays consist of 10,201 thermoluminescent phosphor elements of 40 micron thickness, covering a 900 cm 2 area. Array substrates are 125 micron thick polyimide sheets, enabling them to easily conform to regular surface shapes, especially for survey of surfaces that are inaccessible for standard survey instruments. The passive, integrating radiation detectors are sensitive to alpha and beta radiation at contamination levels below release guideline limits. Required contact times with potentially contaminated surfaces are under one hour to achieve detection of transuranic alpha emission at 100 dpm/100 cm 2 . Positional information obtained from array evaluation is useful for locating contamination zones. Unique capabilities of this system for survey of sites, facilities and material include measurement inside pipes and other geometrical configurations that prevent standard surveys, and below-surface measurement of alpha and beta emitters in contaminated soils. These applications imply a reduction of material that must be classified as radioactive waste by virtue of its possibility of contamination, and cost savings in soil sampling at contaminated sites

  17. When High-Capacity Readers Slow Down and Low-Capacity Readers Speed Up: Working Memory and Locality Effects.

    Science.gov (United States)

    Nicenboim, Bruno; Logačev, Pavel; Gattei, Carolina; Vasishth, Shravan

    2016-01-01

    We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German), while taking into account readers' working memory capacity and controlling for expectation (Levy, 2008) and other factors. We predicted only locality effects, that is, a slowdown produced by increased dependency distance (Gibson, 2000; Lewis and Vasishth, 2005). Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions.

  18. Facilitating coronary artery evaluation in MDCT using a 3D automatic vessel segmentation tool

    International Nuclear Information System (INIS)

    Fawad Khan, M.; Gurung, Jessen; Maataoui, Adel; Brehmer, Boris; Herzog, Christopher; Vogl, Thomas J.; Wesarg, Stefan; Dogan, Selami; Ackermann, Hanns; Assmus, Birgit

    2006-01-01

    The purpose of this study was to investigate a 3D coronary artery segmentation algorithm using 16-row MDCT data sets. Fifty patients underwent cardiac CT (Sensation 16, Siemens) and coronary angiography. Automatic and manual detection of coronary artery stenosis was performed. A 3D coronary artery segmentation algorithm (Fraunhofer Institute for Computer Graphics, Darmstadt) was used for automatic evaluation. All significant stenoses (>50%) in vessels >1.5 mm in diameter were protocoled. Each detection tool was used by one reader who was blinded to the results of the other detection method and the results of coronary angiography. Sensitivity and specificity were determined for automatic and manual detection as well as was the time for both CT-based evaluation methods. The overall sensitivity and specificity of the automatic and manual approach were 93.1 vs. 95.83% and 86.1 vs. 81.9%. The time required for automatic evaluation was significantly shorter than with the manual approach, i.e., 246.04±43.17 s for the automatic approach and 526.88±45.71 s for the manual approach (P<0.0001). In 94% of the coronary artery branches, automatic detection required less time than the manual approach. Automatic coronary vessel evaluation is feasible. It reduces the time required for cardiac CT evaluation with similar sensitivity and specificity as well as facilitates the evaluation of MDCT coronary angiography in a standardized fashion. (orig.)

  19. Echoic memory processes in good and poor readers.

    Science.gov (United States)

    Sipe, S; Engle, R W

    1986-07-01

    Four experiments were conducted to determine whether echoic memory plays a role in differences between good and poor readers. The first two experiments used a suffix procedure in which the subject is read a list of digits with either a tone control or the word go appended to the list. For lists that exceeded the length of the subjects memory span by one digit (i.e., that avoided ceiling effects), the poor readers showed a larger decrement in the suffix condition than did the good readers. The third experiment was directed at the question of whether the duration of echoic memory is different for good and poor readers. Children shadowed words presented to one ear at a rate determined to give 75-85% shadowing accuracy. The items presented to the nonattended ear were words and an occasional digit. At various intervals after the presentation of the digit, a light signaled that the subject was to cease shadowing and attempt to recall any digit that had occurred in the nonattended ear recently. Whereas good and poor readers recalled the digit equally if tested immediately after presentation, the poor readers showed a faster decline in recall of the digit as retention interval increased. A fourth experiment was conducted to determine whether the differences in echoic memory were specific to speech stimuli or occurred at a more basic level of aural persistence. Bursts of white noise were separated by 9-400 ms of silence and the subject was to say whether there were one or two sounds presented. There were no differences in detectability functions for good and poor readers.

  20. Visual consequences of electronic reader use: a pilot study.

    Science.gov (United States)

    Maducdoc, Marlon M; Haider, Asghar; Nalbandian, Angèle; Youm, Julie H; Morgan, Payam V; Crow, Robert W

    2017-04-01

    With the increasing prevalence of electronic readers (e-readers) for vocational and professional uses, it is important to discover if there are visual consequences in the use of these products. There are no studies in the literature quantifying the incidence or severity of eyestrain, nor are there clinical characteristics that may predispose to these symptoms with e-reader use. The primary objective of this pilot study was to assess the degree of eyestrain associated with e-reader use compared to traditional paper format. The secondary outcomes of this study were to assess the rate of eyestrain associated with e-reader use and identify any clinical characteristics that may be associated with the development of eyestrain. Forty-four students were randomly assigned to study (e-reader iPAD) and control (print) groups. Participant posture, luminosity of the room, and reading distance from reading device were measured during a 1-h session for both groups. At the end of the session, questionnaires were administered to determine symptoms. Significantly higher rates of eyestrain (p = 0.008) and irritation (p = 0.011) were found among the iPAD study group as compared to the print 'control' group. The study group was also 4.9 times more likely to report severe eyestrain (95 % CI [1.4, 16.9]). No clinical characteristics predisposing to eyestrain could be identified. These findings conclude that reading on e-readers may induce increased levels of irritation and eyestrain. Predisposing factors, etiology, and potential remedial interventions remain to be determined.

  1. Automatic quantitative renal scintigraphy

    International Nuclear Information System (INIS)

    Valeyre, J.; Deltour, G.; Delisle, M.J.; Bouchard, A.

    1976-01-01

    Renal scintigraphy data may be analyzed automatically by the use of a processing system coupled to an Anger camera (TRIDAC-MULTI 8 or CINE 200). The computing sequence is as follows: normalization of the images; background noise subtraction on both images; evaluation of mercury 197 uptake by the liver and spleen; calculation of the activity fractions on each kidney with respect to the injected dose, taking into account the kidney depth and the results referred to normal values; edition of the results. Automation minimizes the scattering parameters and by its simplification is a great asset in routine work [fr

  2. AUTOMATIC FREQUENCY CONTROL SYSTEM

    Science.gov (United States)

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  3. Automatic dipole subtraction

    International Nuclear Information System (INIS)

    Hasegawa, K.

    2008-01-01

    The Catani-Seymour dipole subtraction is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. We automatized the procedure in a computer code. The code is useful especially for the processes with many parton legs. In this talk, we first explain the algorithm of the dipole subtraction and the whole structure of our code. After that we show the results for some processes where the infrared divergences of real emission processes are subtracted. (author)

  4. Automatic programmable air ozonizer

    International Nuclear Information System (INIS)

    Gubarev, S.P.; Klosovsky, A.V.; Opaleva, G.P.; Taran, V.S.; Zolototrubova, M.I.

    2015-01-01

    In this paper we describe a compact, economical, easy to manage auto air ozonator developed at the Institute of Plasma Physics of the NSC KIPT. It is designed for sanitation, disinfection of premises and cleaning the air from foreign odors. A distinctive feature of the developed device is the generation of a given concentration of ozone, approximately 0.7 maximum allowable concentration (MAC), and automatic maintenance of a specified level. This allows people to be inside the processed premises during operation. The microprocessor controller to control the operation of the ozonator was developed

  5. Automatic read out system for superheated emulsion based neutron detector

    International Nuclear Information System (INIS)

    Meena, J.P.; Parihar, A.; Vaijapurkar, S.G.; Mohan, Anand

    2010-01-01

    Full text: Defence Laboratory, Jodhpur (DLJ) has developed superheated emulsion technology for neutron and gamma measurements. The laboratory has attempted to develop reader system to display neutron dose and dose rate based on acoustic technique. The paper presents a microcontroller based automatic reader system for neutron measurements using indigenously developed superheated emulsion detector. The system is designed for real time counting of bubbles formed in superheated emulsion detector. A piezoelectric transducer is used for sensing bubble acoustic. The front end of system is mainly consisting of specially designed signal conditioning unit consisted of piezoelectric transducer, an amplifier, a high-pass filter, a differentiator, a comparator and monostable multivibrator. The system is based on PIC 18F6520 microcontroller having large internal SRAM, 10-bit internal ADC, I 2 C interface, UART/USART modules. The paper also describes the design of following peripheral units interfaced to microcontroller temperature and battery monitoring, display, keypad and a serial communication. The reader system measures and displays neutron dose and dose rate, number of bubble and elapsed time. The developed system can be used for detecting very low neutron leakage in the accelerators, nuclear reactors and nuclear submarines. The important features of system are compact, light weight, cost effective and high neutron sensitivity. The prototype was tested and evaluated by exposing to 241 Am-Be neutron source and results have been reported

  6. Automated Low-Cost Smartphone-Based Lateral Flow Saliva Test Reader for Drugs-of-Abuse Detection.

    Science.gov (United States)

    Carrio, Adrian; Sampedro, Carlos; Sanchez-Lopez, Jose Luis; Pimienta, Miguel; Campoy, Pascual

    2015-11-24

    Lateral flow assay tests are nowadays becoming powerful, low-cost diagnostic tools. Obtaining a result is usually subject to visual interpretation of colored areas on the test by a human operator, introducing subjectivity and the possibility of errors in the extraction of the results. While automated test readers providing a result-consistent solution are widely available, they usually lack portability. In this paper, we present a smartphone-based automated reader for drug-of-abuse lateral flow assay tests, consisting of an inexpensive light box and a smartphone device. Test images captured with the smartphone camera are processed in the device using computer vision and machine learning techniques to perform automatic extraction of the results. A deep validation of the system has been carried out showing the high accuracy of the system. The proposed approach, applicable to any line-based or color-based lateral flow test in the market, effectively reduces the manufacturing costs of the reader and makes it portable and massively available while providing accurate, reliable results.

  7. Automated Low-Cost Smartphone-Based Lateral Flow Saliva Test Reader for Drugs-of-Abuse Detection

    Directory of Open Access Journals (Sweden)

    Adrian Carrio

    2015-11-01

    Full Text Available Lateral flow assay tests are nowadays becoming powerful, low-cost diagnostic tools. Obtaining a result is usually subject to visual interpretation of colored areas on the test by a human operator, introducing subjectivity and the possibility of errors in the extraction of the results. While automated test readers providing a result-consistent solution are widely available, they usually lack portability. In this paper, we present a smartphone-based automated reader for drug-of-abuse lateral flow assay tests, consisting of an inexpensive light box and a smartphone device. Test images captured with the smartphone camera are processed in the device using computer vision and machine learning techniques to perform automatic extraction of the results. A deep validation of the system has been carried out showing the high accuracy of the system. The proposed approach, applicable to any line-based or color-based lateral flow test in the market, effectively reduces the manufacturing costs of the reader and makes it portable and massively available while providing accurate, reliable results.

  8. Reader error during CT colonography: causes and implications for training

    International Nuclear Information System (INIS)

    Slater, Andrew; Tam, Emily; Gartner, Louise; Scarth, Julia; Peiris, Chand; Gupta, Arun; Marshall, Michele; Burling, David; Taylor, Stuart A.; Halligan, Steve

    2006-01-01

    This study investigated the variability in baseline computed tomography colonography (CTC) performance using untrained readers by documenting sources of error to guide future training requirements. Twenty CTC endoscopically validated data sets containing 32 polyps were consensus read by three unblinded radiologists experienced in CTC, creating a reference standard. Six readers without prior CTC training [four residents and two board-certified subspecialty gastrointestinal (GI) radiologists] read the 20 cases. Readers drew a region of interest (ROI) around every area they considered a potential colonic lesion, even if subsequently dismissed, before creating a final report. Using this final report, reader ROIs were classified as true positive detections, true negatives correctly dismissed, true detections incorrectly dismissed (i.e., classification error), or perceptual errors. Detection of polyps 1-5 mm, 6-9 mm, and ≥10 mm ranged from 7.1% to 28.6%, 16.7% to 41.7%, and 16.7% to 83.3%, respectively. There was no significant difference between polyp detection or false positives for the GI radiologists compared with residents (p=0.67, p=0.4 respectively). Most missed polyps were due to failure of detection rather than characterization (range 82-95%). Untrained reader performance is variable but generally poor. Most missed polyps are due perceptual error rather than characterization, suggesting basic training should focus heavily on lesion detection. (orig.)

  9. CT colonography: effect of experience and training on reader performance

    International Nuclear Information System (INIS)

    Taylor, Stuart A.; Burling, David; Morley, Simon; Bartram, Clive I.; Halligan, Steve; Bassett, Paul; Atkin, Wendy

    2004-01-01

    The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training (P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow (P<0.001 and P=0.03, respectively), but increased for the trainee (P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases. (orig.)

  10. Development of optically stimulated luminescence reader systems in BARC

    International Nuclear Information System (INIS)

    Kulkarni, M.S.

    2008-01-01

    BARC has very vast experience in the development of thermoluminescence (TL) reader systems both for routine personnel monitoring and research application. However, optically stimulated luminescence (OSL) related instrumentation is a recent development in BARC. The increasing popularity of OSL technique in the radiation dosimetry applications in the recent past has driven investigation and developmental programme in the OSL measurement facilities at BARC. As the consequence of the efforts directed towards the indigenous development of OSL reader system, OSL readers with various readout modes like continuous wave (CW) OSL mode, linear intensity modulated OSL (LM-OSL), pulsed OSL (POSL) have been developed. In addition to these conventional modes of operation a novel non-linear OSL mode (NL-OSL) has also been developed for the OSL measurements. This paper reviews the details of the development of OSL reader system including experience with high intensity blue/green LED stimulation light source and detection system. Also discussed are recently developed versatile integrated TL/OSL reader systems for TL and OSL measurements. (author)

  11. A study on the development of an infographic reader questionnaire and reader opinions

    Directory of Open Access Journals (Sweden)

    Yıldırım Serkan

    2016-01-01

    Full Text Available Educational materials are commonly used to assist with communication during learning. One of the ways to determine the use of educational materials and their contribution to the learning process is to ask students for their opinions. Student opinions provide useful information regarding various objectives such as making both the learning process and resources more effective, bringing about the necessary improvements and organising the teaching process. In this study, we developed a questionnaire for determining the opinions of information graphics (infographics readers on information graphics prepared for teaching purposes. This study was conducted in the fall semester of the 2013-2014 academic year with the participation of 59 students from the Department of Computer and Instructional Technologies Education of the Kazım Karabekir Faculty of Education. The students were provided with a questionnaire consisting of 29 items that inquired their opinions on infographics. The collected data were assessed using Principal Component Analysis. Based on the analysis results, a second questionnaire consisting of 23 items and six factors (Learnability, Selection Preferences, Sharing, Basic Presentation Structure, Memorability, and Role in the Learning Process was developed. According to the study results, the students considered infographics as highly instructive, and described that they help ensure a more lasting learning experience.

  12. Automatic sets and Delone sets

    International Nuclear Information System (INIS)

    Barbe, A; Haeseler, F von

    2004-01-01

    Automatic sets D part of Z m are characterized by having a finite number of decimations. They are equivalently generated by fixed points of certain substitution systems, or by certain finite automata. As examples, two-dimensional versions of the Thue-Morse, Baum-Sweet, Rudin-Shapiro and paperfolding sequences are presented. We give a necessary and sufficient condition for an automatic set D part of Z m to be a Delone set in R m . The result is then extended to automatic sets that are defined as fixed points of certain substitutions. The morphology of automatic sets is discussed by means of examples

  13. Cognitive Processes in Discourse Comprehension: Passive Processes, Reader-Initiated Processes, and Evolving Mental Representations

    Science.gov (United States)

    van den Broek, Paul; Helder, Anne

    2017-01-01

    As readers move through a text, they engage in various types of processes that, if all goes well, result in a mental representation that captures their interpretation of the text. With each new text segment the reader engages in passive and, at times, reader-initiated processes. These processes are strongly influenced by the readers'…

  14. Struggling Readers: Assessment and Instruction in Grades K-6. Solving Problems in the Teaching of Literacy.

    Science.gov (United States)

    Balajthy, Ernest; Lipa-Wade, Sally

    This book focuses on three distinct types of struggling readers that teachers will instantly recognize from their own classrooms--the "Catch-On Reader," the "Catch-Up Reader," and the "Stalled Reader." The book provides detailed case studies which bring to life the specific problems these students are likely to face…

  15. Using Twitter to Teach Reader-Oriented Biblical Interpretation: "Tweading" the Gospel of Mark

    Science.gov (United States)

    Williamson, Robert, Jr.

    2013-01-01

    Twitter offers an engaging way to introduce students to reader-oriented interpretation of the Bible. The exercise described here introduces students to the idea that the reader has a role in the production of a text's meaning, which thus varies from reader to reader. Twitter enables us to capture the real-time thoughts of a variety of…

  16. How Do Fluent and Poor Readers' Endurance Differ in Reading?

    Science.gov (United States)

    Bastug, Muhammet; Keskin, Hasan Kagan; Akyol, Mustafa

    2017-01-01

    It was observed in this research how endurance status of fluent readers and poor readers changed as the text became longer. 40 students of the primary school 4th-grade, 20 were fluent readers and other 20 were poor readers, participated in the research. A narrative text was utilised in the data collection process. Students' oral readings were…

  17. When high-capacity readers slow down and low-capacity readers speed up: Working memory and locality effects

    Directory of Open Access Journals (Sweden)

    Bruno eNicenboim

    2016-03-01

    Full Text Available We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German, while taking into account readers’ working memory capacity and controlling for expectation (Levy, 2008 and other factors. We predicted only locality effects, that is, a slow-down produced by increased dependency distance (Gibson, 2000; Lewis & Vasishth, 2005. Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions.

  18. Automatic identification in mining

    Energy Technology Data Exchange (ETDEWEB)

    Puckett, D; Patrick, C [Mine Computers and Electronics Inc., Morehead, KY (United States)

    1998-06-01

    The feasibility of monitoring the locations and vital statistics of equipment and personnel in surface and underground mining operations has increased with advancements in radio frequency identification (RFID) technology. This paper addresses the use of RFID technology, which is relatively new to the mining industry, to track surface equipment in mine pits, loading points and processing facilities. Specific applications are discussed, including both simplified and complex truck tracking systems and an automatic pit ticket system. This paper concludes with a discussion of the future possibilities of using RFID technology in mining including monitoring heart and respiration rates, body temperatures and exertion levels; monitoring repetitious movements for the study of work habits; and logging air quality via personnel sensors. 10 refs., 5 figs.

  19. Automatic quantitative metallography

    International Nuclear Information System (INIS)

    Barcelos, E.J.B.V.; Ambrozio Filho, F.; Cunha, R.C.

    1976-01-01

    The quantitative determination of metallographic parameters is analysed through the description of Micro-Videomat automatic image analysis system and volumetric percentage of perlite in nodular cast irons, porosity and average grain size in high-density sintered pellets of UO 2 , and grain size of ferritic steel. Techniques adopted are described and results obtained are compared with the corresponding ones by the direct counting process: counting of systematic points (grid) to measure volume and intersections method, by utilizing a circunference of known radius for the average grain size. The adopted technique for nodular cast iron resulted from the small difference of optical reflectivity of graphite and perlite. Porosity evaluation of sintered UO 2 pellets is also analyzed [pt

  20. Semi-automatic fluoroscope

    International Nuclear Information System (INIS)

    Tarpley, M.W.

    1976-10-01

    Extruded aluminum-clad uranium-aluminum alloy fuel tubes must pass many quality control tests before irradiation in Savannah River Plant nuclear reactors. Nondestructive test equipment has been built to automatically detect high and low density areas in the fuel tubes using x-ray absorption techniques with a video analysis system. The equipment detects areas as small as 0.060-in. dia with 2 percent penetrameter sensitivity. These areas are graded as to size and density by an operator using electronic gages. Video image enhancement techniques permit inspection of ribbed cylindrical tubes and make possible the testing of areas under the ribs. Operation of the testing machine, the special low light level television camera, and analysis and enhancement techniques are discussed