Design, construction and testing of a self-powered neutron detector

International Nuclear Information System (INIS)

Correa, R.F.

1987-01-01

The design, construction and testing of a self-powered neutron detector (SPN) and associated electronics are described. Several tests were performed giving information about dielectrical properties of detector and cable, gamma spectra induced in the detector through reactor irradiation, detector response as a function of neutron flux, current stability and reproductibility with the neutron flux. The gamma and neutron sensitivities were also evaluated, by means of thermoluminescent dosimeters and gold foils as references. The test results are presented and show that the detector response is reliable. The gamma and neutron sensitivities are in agreement with those found in the available literature. Nevertheless, a ceramic insulated cable should be employed for permanent use in a reactor. The tests were performed in a 100 KW TRIGA Mark I reactor at the Centro de Desenvolvimento da Tecnologia Nuclear of NUCLEBRAS, in Belo Horizonte, Brazil. (author) [pt

Design constrution and testing of a self-powered neutron detector

International Nuclear Information System (INIS)

Correa, R.F.

1987-01-01

The design, contruction and testing of a self-powered neutron detector (SPN) and associated electronics are described. Several tests were performed giving information about dielectrical properties od detector and cable, gamma spectra induced in the detector through reactor irradiation, detector response as a function of neutron flux, current stability and reproductibility with the neutron flux. The gamma and neutron sensitivities were also evaluated, by means of thermoluminescent dosimeters and gold foils as references. The test results are presented and show that the detector response is reliable. The gamma and neutron sensitivities are in agreement with those found in the available literature. Neverthe less, a ceramic insulated cable should be employed for permanent use in a reactor. The tests were perfomance in a 100 kW TRIGA Mark I reactor at the Centro de Desenvolvimento da Tecnologia Nuclear of NUCLEBRAS,in Belo Horizonte, Brazil. (Author) [pt

Sensitivity of various thermoluminescent, radiophotoluminescent and photographic detectors to neutrons emitted by a 252Cf source

International Nuclear Information System (INIS)

Spurny, Frantisek; Medioni, Roger; Chapuis, A.; Portal, Guy.

1975-07-01

The specific sensitivity of various thermoluminescent, radiophotoluminescent and photographic detectors to the neutron spectrum of a 252 Cf source was measured and the effect of the size and composition of the containers in which they might be put was investigated. PB33 radiophotoluminescent glasses, radiothermoluminescent alumina and calcium sulfate were less sensitive to fission neutrons whereas photographic emulsions were more sensitive. The former should be used for γ detection in mixed fields of photons and fission neutrons [fr

Radiation detectors

International Nuclear Information System (INIS)

2013-01-01

This sixth chapter presents the operational principles of the radiation detectors; detection using photographic emulsions; thermoluminescent detectors; gas detectors; scintillation detectors; liquid scintillation detectors; detectors using semiconductor materials; calibration of detectors; Bragg-Gray theory; measurement chain and uncertainties associated to measurements

Thermoluminescence dosemeter for personal dose equivalent assessment

International Nuclear Information System (INIS)

Silva, T.A. da; Rosa, L.A.R. da; Campos, L.L.

1995-01-01

The possibility was investigated of utilising a Brazilian thermoluminescence individual dosemeter, usually calibrated in terms of photon dose equivalent, for the assessment of the personal dose equivalent, H p (d), at depths of 0.07 and 10 mm. The dosemeter uses four CaSO 4 :Dy thermoluminescent detectors, between different filters, as the sensitive materials. It was calibrated in gamma and X radiation fields in the energy range from 17 to 1250 keV. Linear combinations of the responses of three detectors, in this energy range, allow the evaluation of H p (0.07) and H p (10), for radiation incidence angles varying from 0 to 60 degrees, with an accuracy better than 35%. The method is not applicable to mixed photon-beta fields. (author)

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.

Thermoluminescence dosimetry in Northwest Puerto Rico

International Nuclear Information System (INIS)

Block, A.M.; Clements, R.G.; Rosa, L.I.; Santos, F.

1975-01-01

In October, 1973, the Puerto Rico Water Resources Authority sought the initiation of studies aimed at determining background radiological characteristics of the northwestern quadrant of Puerto Rico using thermoluminescent dosemeters. Some of the studies were required for supporting data for the environmental report submitted as part of the licensing procedure in the establishment of thermonuclear electric power generation facilities in Barrio Islote, Arecibo, Puerto Rico. Previous studies of radiological characteristics of the area had been made using sodium iodide sensing equipment in an airplane flying at an altitude of 500 ft. The results are expressed in counts per second, and provide useful comparative levels for radioactivity measured with the thermoluminescent detectors. (U.S.)

Oxidation/reduction effects on sapphire thermoluminescent detectors

International Nuclear Information System (INIS)

Molnar, G.; Borossay, J.; Suevegh, K.; Vertes, A.

1998-01-01

Complete text of publication follows. The thermoluminescence (TL) and thermally stimulated exoemission (TSEE) properties of Al 2 O 3 has been extensively studied during the past 40 years. It has been suggested as a dosemeter for both ultraviolet light and ionising radiation. Nevertheless the connection between the structure (point defects) of alumina and thermally stimulated relaxation processes has not yet been clearly explained. In this work α-Al 2 O 3 single crystal samples were studied in order to determine the mechanism of electron-hole processes of thermoluminescence and thermally stimulated exoelectron emission peaks. Single crystals prepared in highly reducing conditions were treated in different atmospheres (reducing/oxidising) and their optical absorption (after isochronous annealing), fluorescence, positron-annihilation and TL properties were investigated. Changes of optical absorption and positron annihilation spectra of oxidised samples suggest that Schottky-type defect formation occurred - the concentration of Al-vacancies increased while that of O-vacancies decreased. Also we observed the oxidation of Ti 3+ to Ti 4+ . The reduction of an oxidised sample led to the diminution of Al-vacancy concentration while that of O-vacancies has not been changed. This suggest a Frenkel-type cationic defect. We also tried to correlate these changes to changes of TL glow curves and to explain the origin of some TL peaks

Quality control of thermoluminesce personal dose monitoring

International Nuclear Information System (INIS)

Shang Aiguo; He Wenchang; Zhao Fengtao

2006-01-01

In order to evaluate the influence factor to thermoluminesce personal dose monitoring result, the every question that can appear based on the fact was analyzed. The results show that the detector, annealing, measuring process can influence the monitoring result. It gives some measures to enhance monitoring quality. (authors)

Calibration procedure for thermoluminescent dosemeters in water absorbed doses for Iridium-192 high dose rate sources

International Nuclear Information System (INIS)

Reyes Cac, Franky Eduardo

2004-10-01

Thermoluminescent dosimeters are used in brachytherapy services quality assurance programs, with the aim of guaranteeing the correct radiation dose supplied to cancer patients, as well as with the purpose of evaluating new clinical procedures. This work describes a methodology for thermoluminescent dosimeters calibration in terms of absorbed dose to water for 192 Ir high dose rate sources. The reference dose used is measured with an ionization chamber previously calibrated for 192 Ir energy quality, applying the methodology proposed by Toelli. This methodology aims to standardizing the procedure, in a similar form to that used for external radiotherapy. The work evolves the adaptation of the TRS-277 Code of the International Atomic Energy Agency, for small and big cavities, through the introduction for non-uniform experimental factor, for the absorbed dose in the neighborhood of small brachytherapy sources. In order to simulate a water medium around the source during the experimental work, an acrylic phantom was used. It guarantees the reproducibility of the ionization chamber and the thermoluminescent dosimeter's location in relation to the radiation source. The values obtained with the ionization chamber and the thermoluminescent dosimeters, exposed to a 192 Ir high dose rate source, were compared and correction factors for different source-detector distances were determined for the thermoluminescent dosimeters. A numeric function was generated relating the correction factors and the source-detector distance. These correction factors are in fact the thermoluminescent dosimeter calibration factors for the 192 Ir source considered. As a possible application of this calibration methodology for thermoluminescent dosimeters, a practical range of source-detector distances is proposed for quality control of 192 Ir high dose rate sources. (author)

Thermoluminescence measurements of neutron streaming through JET Torus Hall ducts

OpenAIRE

Obryk, Barbara; Batistoni, Paola; Conroy, Sean; Syme, Brian D.; Popovichev, Sergey; Stamatelatos, Ion E.; Vasilopoulou, Theodora; Bilski, Paweł; Contributors, JET EFDA

2014-01-01

Thermoluminescence detectors (TLD) were used for dose measurements at JET. Several hundreds of LiF detectors of various types, standard LiF:Mg,Ti and highly sensitive LiF:Mg,Cu,P were produced. LiF detectors consisting of natural lithium are sensitive to slow neutrons, their response to neutrons being enhanced by 6Li-enriched lithium or suppressed by using lithium consisting entirely of 7Li. Pairs of 6LiF/7LiF detectors allow distinguishing between neutron/non-neutron components of a radiatio...

In vivo dosimetry with semiconductor and thermoluminescent detectors applied to head and neck cancer treatment; Dosimetria in vivo com uso de detectores semicondutores e termoluminescentes aplicada ao tratamento de cancer de cabeca e pescoco

Energy Technology Data Exchange (ETDEWEB)

Viegas, Claudio Castelo Branco

2003-03-15

In vivo dosimetry in radiotherapy, i. e, the assessment of the doses received by patients during their treatments, permits a verification of the therapy quality. A routine of in vivo dosimetry is, undoubtedly, a direct benefit for the patient. Unfortunately, in Brazil and in Latin America this procedure is still a privilege for only a few patients. This routine is of common application only in developed countries. The aim of this work is to show the viability and implementation of a routine in vivo dosimetry, using diodes semiconductors and thermoluminescent dosimeters (TLD), at the radiotherapy section of the National Institute of Cancer in Brazil, in the case of head and neck cancer treatment. In order to reach that aim, the characteristics of the response of diodes ISORAD-p and LiF:Mg;Ti (TLD-100) thermoluminescent detectors in powder form were determined. The performance of those detectors for in vivo dosimetry was tested using an RANDO Alderson anthropomorfic phantom and, once their adequacy proved for the kind of measurements proposed, they were used for dose assessment in the case of tumour treatments in the head and neck regions, for Cobalt-60 irradiations. (author)

Technical recommendations for the use of thermoluminescence for dosimetry in individual monitoring for photons and electrons from external sources

International Nuclear Information System (INIS)

1975-01-01

The principles of thermoluminescence dosimetry and the role it may play in the field of personnel dosimetry are presented. Technical recommendations are made as an indication of what is generally regarded as good practice and they are intended to be of assistance in avoiding the common sources of error. Errors due to: the detector; the evaluation procedure; the thermal treatment; at the sensitivity of the detector to neutrons. The recommendations are concerned with: the choice of detector material; design of thermoluminescent dosemeters; read-out procedure; reader; handling procedures; dose evaluations; automation; documentation and data handling

A microcomputer controlled thermoluminescence dosimetry system

International Nuclear Information System (INIS)

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

1980-01-01

Using a microcomputer, an automatic thermoluminescence dosimetry system for personal dosimetry and thermoluminescence detector (TLD) research was developed. Process automation, statistical computation and dose calculation are provided by this microcomputer. Recording of measurement data, as well as dose record keeping for radiological workers is carried out with floppy disk. The microcomputer also provides a human/system interface by means of a video display and a printer. The main features of this dosimetry system are its low cost, high degree of flexibility, high degree of automation and the feasibility for use in routine dosimetry as well as in TLD research. The system is in use for personal dosimetry, environmental dosimetry and for TL-research work. Because of its modular set-up several components of the system are in use for other applications, too. The system seems suited for medium sized health physics groups. (author)

Thermoluminescence and applications

International Nuclear Information System (INIS)

Rodrigues, G.V.

1986-01-01

The theory of thermoluminescent emission, the characteristics of main thermoluminescent phosphorus, and some applications are presented. The main thermoluminescent dosemeters used in dosimetry are related. (M.C.K.)

Neutron Activation and Thermoluminescent Detector Responses to a Bare Pulse of the CEA Valduc SILENE Critical Assembly

Energy Technology Data Exchange (ETDEWEB)

Miller, Thomas Martin [ORNL; Isbell, Kimberly McMahan [ORNL; Lee, Yi-kang [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Gagnier, Emmanuel [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Authier, Nicolas [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille; Piot, Jerome [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille; Jacquet, Xavier [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille; Rousseau, Guillaume [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille; Reynolds, Kevin H. [Y-12 National Security Complex

2016-09-01

This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 11, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

Improved processes in therapy dosimetry with solid LiF thermoluminescent detectors

International Nuclear Information System (INIS)

Toivonen, M.

1991-08-01

The thesis presents criteria for thermoluminescence dosimetry systems suitable for precision measurements and, moreover, a detailed examination of the sources of systematic and random error. Instructions are given for annealing processes, calibration procedures, quality control, and operational rules, which are necessary in modem TLD. The performances of some principally different systems are compared. The old LiF-powder-based TLD system, with an overall uncertainty of measurement of about 1.6 percent for ten repeated readouts and for irradiations under calibration conditions with Co-60, is still the best but a comparable, although slightly lower, accuracy of about 1.7 percent can be reached more conveniently with solid LiF detectors. In measurements where absolute system calibration is not of interest (i.e., in depth-dose curve measurements, etc.), the advantages of the simple powder-based system are even more concrete. An integrated TLD process is presented for progressive utilization of automation in precision measurements. The sources of random error and unknown systematic error in current readout instruments are examined. Mechanical tolerances in critical parts of the readout instruments are thought to be the reason why the method of heating with hot gas has not been superior with respect to the precision of measurements, in spite of the excellent repeatability of the glow curve shape observed for successive readouts

Implantation of a new Beta Secondary Standard system at Centro de Desenvolvimento da Tecnologia Nuclear

International Nuclear Information System (INIS)

Reynaldo, Sibele Reis

2005-01-01

The crescent use of beta radiation sources in medical, industrial and research applications has increased the need for higher accuracy in beta dosimetry. As the first Beta Secondary Standard system (BSS1) was developed about 20 years ago, a new BSS2 system was made commercially available to fulfill new metrological demands and to follow the technological development. The BSS2 has a new positioning set-up, high activity and long half-life beta radiation sources and a special safety system. The Centro de Desenvolvimento da Tecnologia Nuclear is the first laboratory in Latin America that has got a BSS2. This work describes the BSS2 and it compares its advantages in relation to BSS1; results of the beam uniformity tests of the radiation fields from 90 Sr/ 90 Y, 85 Kr and 147 Pm sources, that were measured with an ionization chamber and with thermoluminescent detectors, are also shown. Results show that the beta radiation fields are considered to be uniform for diameters between 8 and 20 cm according to the chosen source. (author)

Handbook of thermoluminescence

CERN Document Server

Furetta, Claudio

2010-01-01

This second edition of the Handbook of Thermoluminescence enlarges on all the subjects which were treated in the first edition and adds further arguments, including the theory of thermoluminescent dose measurement, several examples concerning the kinetics parameters determination using various methods such as peak shape, isothermal decay, and so on. A special section is devoted to food irradiation, an important subject at the present time, and to the thermoluminescent characterization of the minerals extracted from the irradiated food. Another new section is devoted to the thermoluminescent ph

Thermoluminescence study of quartzite in a gold and uranium mineralized zone (Canavieiras, Jacobina-Bahia)

International Nuclear Information System (INIS)

Ferreira, J.

1973-01-01

The quartzite of Canavieiras gold mine (Jacobina-Bahia, Brazil) shows in its natural glow curve, a high temperature. The study of the reproductibility of this peak resulted in the standartization of measurement for grain sizes between 80 and 100 mesh. ''In Situ'' total gamma-ray profiles were made using a scintillation detector for the study the distribution of radioactive elements near the pirite, uranium and gold strike. In the interpretation of the profiles it was possible to shown a positive correlation between thermoluminescence and uranium yields. The thermoluminescence peak is sufficiently high temperature peak to let thermoluminescence accumulate at ambient temperatures. It was used in attempt to estimate the time and the event that enitiated the accumulation of thermoluminescence. The result obtained, (7 - + 4).10 6 years, may correspond to the last heating of the rocks at relatively recent time. (C.D.G.) [pt

Accuracy and precision in thermoluminescence dosimetry

International Nuclear Information System (INIS)

Marshall, T.O.

1984-01-01

The question of accuracy and precision in thermoluminescent dosimetry, particularly in relation to lithium fluoride phosphor, is discussed. The more important sources of error, including those due to the detectors, the reader, annealing and dosemeter design, are identified and methods of reducing their effects on accuracy and precision to a minimum are given. Finally, the accuracy and precision achievable for three quite different applications are discussed, namely, for personal dosimetry, environmental monitoring and for the measurement of photon dose distributions in phantoms. (U.K.)

The minimum measurable dose of CaF{sub 2}:Dy measured via an improved heating profile with an automatic 6600 thermoluminescent detector

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

One of the advantages of the thermoluminescent method is its ability to measure low doses, which is useful in environmental dosimetry, as well as in archaeology. The CaF{sub 2}:Dy (Crown as TLD-200), has a sensitivity of 10-30 times greater than the sensitivity of TLD-100, when irradiated by Cs-137. In the present work we evaluated the TL-dose response of CaF{sub 2}:Dy, by using an improved heating profile which is giving the main glow peak alone. The relative standard deviations were fitted to a semiempirical expression, from which the minimum measurable doses (MMD) were derived. The MMD were calculated by taking 3 times the standard deviation of the unirradiated chips. The results of the TL-dose response, as well as file fee calculated MMD by taxing 3 times the standard deviation of unirradiated chips, measured by file new 6600 automatic thermoluminescent detector, are presented in this work. We received a MMD of about 0.01 mGy (1 mrad), an improvement of a factor of 2.5 relatively to the integral light response evaluation using the standard heating profile (authors).

Thermoluminescence and their applications

International Nuclear Information System (INIS)

Rodrigues, G.V.

1986-01-01

The theory involved in the phenomenon of thermoluminescence emission, the characteristics of the main thermoluminescent phosphorus and some of their applications are presented. Some of the main thermoluminescent dosemeters used in dosimetry are described. (M.C.K.) [pt

Method of thermoluminescent measurement of radiation doses from micrograys up to a megagray with a single LiF: Mg,Cu,P detector

International Nuclear Information System (INIS)

Obryk, B.; Bilski, P.; Olko, P.

2011-01-01

On the basis of the newly discovered behaviour of LiF:Mg,Cu,P detectors at high and ultra-high doses, a new method of thermoluminescence (TL) measurement of radiation doses ranging from micrograys up to a megagray, has been recently developed at the Inst. of Nuclear Physics (IFJ). The method is based on the relationship between the TL signal, integrated in the given temperature range and dose. It is quantified by a parameter called the 'ultra-high temperature ratio'. It has been demonstrated that this new method can measure radiation doses in the range of about 1 μGy to 1 MGy, using a single LiF:Mg,Cu,P detector. This method was recently successfully blindly tested for 10 MeV electrons up to doses of 200 kGy. It can be used for dosimetry in high-energy accelerators, especially in the Large Hadron Collider at CERN, and has great potential for accident dosimetry in particular. (authors)

Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium

International Nuclear Information System (INIS)

Barboza F, M.; Melendrez, R.; Castaneda, B.; Pedroza M, M.; Chernov, V.; Perez S, R.; Aceves, R.

2000-01-01

Recent research results are presented about the properties of the optical processes of photo transferred thermoluminescence (TLFT), optical whitening (BO), thermoluminescence induced by light (TLL) and its effect in the thermoluminescent curve (Tl) produced by ionizing and non-ionizing radiation. The systematic analysis of all these processes, acquires a singular importance due that actually the alkaline halogenide crystals are object of intense investigations which analyse their potential applications as detectors and radiation dosemeters through stimulated optical luminescence techniques or thermoluminescence. The obtained data show that the Tl curve of material with this nature can be enormously affected by exposure of phosphorus to the environmental light or UV. This is in part due to liberation processes of charge bearers are shouted and makes a subsequent trapping in less temperature traps; at the same time that induce changes in the intensity of determined Tl bands. Additionally, also it is observed that mentioned phenomena are related as with wavelength of incident light as of the illumination time. Finally, the obtained information allows to conclude that although the illumination effect is extremely complex, it is associated and can be explained mainly with phenomena that implicate the electrons excitation trapped in form of F centers and trapping mechanisms or radioactive and non-radioactive recombination. (Author)

Study of a new dosimetric radio-thermoluminescent systems

International Nuclear Information System (INIS)

Cazac, T.C.

1980-01-01

This is the first Romanian study to investigate conditions to obtain the radio-thermo-luminescent systems: MgB 4 O 7 :A(A-Nd,Sm,Eu,Dy,Tb,Dy+Sm and Tb+Sm) MgF 2 A (A=Mn,Dy,Tb,Sm,Li), their essential dosimetric characters, as well as the (MgF 2 =Mn) thermophosphorus mixture with a ( 6 LiF) lithium target. An investigation was developed upon a new category of radio-thermoluminescent detectors with low radiation energy dependence and fading, magnesjum boride activated by several elements of the lanthanides class (Nd,Sm,Eu,Dy,Tb). A new radio-thermoluminescent dosimetric system with high sensitivity and moderate dependence on energy radiation - (Mnsup(2+)) manganese activated magnesium fluoride - was also studied. The author explored application of investigated detectors MgF 2 =Mn, MgB 4 O 7 =Dy and MgB 4 O 7 :Tb in neutron dosimetry in complex gamma-neutron fields. It is deemed that by using the dosimetric systems reported in the thesis in order to measure gamma, beta and neutron radiation doses, dosimetric control can be ensured both in professional dosimetry and in nuclear accident dosimetry, as well as in various basic and applicative investigations. A modest contribution is thus made towards achieving the national nuclear program through an extension of the thermophosphorus range with practical applications in nuclear radiation dosimetry. (author)

Measurement of dose enhancement close to high atomic number media using optical fibre thermoluminescence dosimeters

International Nuclear Information System (INIS)

Alalawi, Amani I.; Hugtenburg, R.P.; Abdul Rahman, A.T.; Barry, M.A.; Nisbet, A.; Alzimami, Khalid S.; Bradley, D.A.

2014-01-01

Present interest concerns development of a system to measure photoelectron-enhanced dose close to a tissue interface using analogue gold-coated doped silica-fibre thermoluminescence detectors and an X-ray set operating at 250 kVp. Study is made of the dose enhancement factor for various thicknesses of gold; measurements at a total gold thickness of 160 nm (accounting for incident and exiting photons) produces a mean measured dose enhancement factor of 1.33±0.01 To verify results, simulations of the experimental setup have been performed. - Highlights: • Dose enhancement • Thermoluminescence dosimeter • Monte Carlo simulation

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

Dosimetric Characteristics of a LKB:Cu,Mg Solid Thermoluminescence Detector

International Nuclear Information System (INIS)

Alajerami Yasser Saleh Mustafa; Hashim Suhairul; Ramli Ahmad Termizi; Saleh Muneer Aziz; Kadir Ahmad Bazlie Bin Abdul; Saripan, Mohd. Iqbal

2013-01-01

We present the main thermoluminescence characteristics of a newly borate glass dosimeter modified with lithium and potassium carbonate (LKB) and co-doped with CuO and MgO. An enhancement of about three times has been shown with the increment of 0.1mol% MgO as a co-dopant impurity. The effects of dose linearity, storage capacity, effective atomic number and energy dose response are studied. The proposed dosimeter shows a simple glow curve, good linearity up to 10 3 Gy, close effective atomic number and photon energy independence. The current results suggest using the proposed dosimeter in different dosimetric applications

THERMOLUMINESCENT DOSIMETRY

Energy Technology Data Exchange (ETDEWEB)

Malsky, Stanley J.; Amato, Charles G.; Roswit, Bernard

1963-06-15

The performance of CaF/sub 2/: Mn and LiF as thermoluminescent in vivo dosimeters is studied. The facility with which this type of dosimeter can be inserted into the body is discussed. The dosimeter is inserted into the body by trocar or catheter techniques and exposed to radiation; it is then removed and heated, and the thermoluminescence is measured and used as an indication of the absorbed dose. (T.F.H.)

Thermoluminescent dosimetry: theory, materials and applications

International Nuclear Information System (INIS)

Rosa, L.A.R.da.

1978-01-01

A survey about the thermoluminescence theory, the properties of the main thermoluminescent phosphors and their applications is presented. Some of the most important thermoluminescent readers are also mentioned [pt

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.

Thermoluminescence albedo-neutron dosimetry

International Nuclear Information System (INIS)

Strand, T.; Storruste, A.

1986-10-01

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

Electron beam energy monitoring using thermoluminescent dosimeters and electron back scattering

International Nuclear Information System (INIS)

Nelson, Vinod; Gray, Alison

2013-01-01

Periodic checks of megavoltage electron beam quality are a fundamental requirement in ensuring accurate radiotherapy treatment delivery. In the present work, thermoluminescent dosimeters (TLDs) positioned on either side of a lead sheet at the surface of a water equivalent phantom were used to monitor electron beam quality using the electron backscattering method. TLD100 and TLD100H were evaluated as upstream detectors and TLD200, TLD400 and TLD500 were evaluated as downstream detectors. The evaluation assessed the test sensitivity and correlation, long and short term reproducibility, dose dependence and glow curve features. A prototype of an in-air jig suitable for use in postal TLD dose audits was also developed and an initial evaluation performed. The results indicate that the TLD100-TLD200 combination provides a sensitive and reproducible method to monitor electron beam quality. The light weight and easily fabricated in-air jig was found to produce acceptable results and has the potential to be used by radiation monitoring agencies to carry out TLD postal quality assurance audits, similar to audits presently being conducted for photon beams. -- Highlights: ► Monitoring electron beam quality via electron backscattering was investigated. ► Different thermoluminescent materials were evaluated as detectors. ► A TLD100-TLD200 combination produced the most sensitive and reproducible results. ► An in-air jig was evaluated to allow measurements via postal dose audits

Thermoluminescence: how safe are we? ask the crystals

International Nuclear Information System (INIS)

Madiyal, Ananya; Alva, Priyadharshini

2013-01-01

Thermoluminescence means 'light emitted from heat'. Thermoluminescent dosimeter (TLD) is a type of radiation measuring instrument used for the measurement of actual dose received by the operator or patient as a result of radiographic exposure. TLD calculates the ionising radiation exposure by measuring the amount of visible light emitted from a crystal in the detector when the crystal is heated. The two types of TLD are Calcium Fluoride type and the Lithium Fluoride type. The former is used for environmental detection of radiation exposure while the latter is used for detection of personal radiation exposure. A TLD card consists of a nickel plated aluminium plate and 3 filters. The equipment used to heat the exposed material and measure the emitted light produced by heat is called TLD reader. It comprises of a heater, a photomultiplier tube and the electronic system. TLD is used to measure the dose received by a patient while undergoing radiotherapy, for radio-diagnosis and as personnel monitoring devices. It has the advantage of being small in size, chemically inert, accurate and gives a reproducible reading. (author)

Thermoluminescence dating method

International Nuclear Information System (INIS)

Zink, A.

2004-01-01

A crystal that is submitted to radiation stores energy and releases this energy under the form of light whenever it is heated. These 2 properties: the ability to store energy and the ability to reset the energy stored are the pillars on which time dating methods like thermoluminescence are based. A typical accuracy of the thermoluminescence method is between 5 to 7% but an accuracy of 3% can be reached with a sufficient number of measurement. This article describes the application of thermoluminescence to the dating of a series of old terra-cotta statues. This time measurement is absolute and does not require any calibration, it represents the time elapsed since the last heating of the artifact. (A.C.)

Thermoluminescent dosimeter system

International Nuclear Information System (INIS)

Felice, P.E.; Gonzalez, J.L.; Seidel, J.G.

1979-01-01

An improved thermoluminescent dosimeter system and apparatus for sensing alpha particle emission is described. A thermoluminescent body is sealed between a pair of metallized plastic films. The dosimeter is mounted within a protective inverted cup or a tube closed at one end, which is disposed in a test hole for exposure to radioactive radon gas which is indicaive of uranium deposits

Unraveling thermoluminescence

CERN Document Server

Sunta, C M

2014-01-01

The book is essentially about the theoretical aspects of thermoluminescence (TL). It is structured and written in a manner which will specially be of interest to the fresh undergraduate students and young researchers planning to take up work in the field of thermoluminescence. It is arranged into seven chapters, starting with the historical growth of the subject of TL and an overview of the luminescence phenomena. A Physical model involving thermally disconnected deep traps is specially described. Using this model expressions are derived for the TL intensity growth curve, the supralinearity fa

Thermoluminescence of LaAlO3

International Nuclear Information System (INIS)

Morales H, A.; Zarate M, J.; Rivera M, T.; Azorin N, J.

2015-10-01

In this paper the thermoluminescent properties of doped lanthanum aluminate (LaAlO 3 ) with dysprosium ion (Dy) were studied. The thermoluminescence characteristics in the samples were obtained using an ultraviolet radiation of 220 nm. The LaAlO 3 :Dy samples were prepared by the modified Pechini method (Spray Dryer). The structural and morphological characterization was obtained by X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques respectively. The size particle composing the agglomerate was determined by Sem, agglomerated particles composed size of 2μm were observed. The thermoluminescence response of LaAlO 3 :Dy was compared with that obtained with the undoped sample. Thermoluminescence brightness curves of LaAlO 3 :Dy showed a peak centered at 185 grades C. Sensitivity of doped sample was greater, about 100 times compared with the undoped sample. Thermoluminescence response in function of the wavelength showed a maximum at 220 nm. Also the fading in thermoluminescence response was studied. (Author)

Mexican gems as thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorin N, J.

1979-01-01

The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10 -2 to 10 2 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

Performance of thermoluminescent materials for high dose dosimetry

International Nuclear Information System (INIS)

Texeira, Maria I.; Cecatti, Sonia G.P.; Caldas, Linda V.E.

2008-01-01

Cases involving high-doses of ionizing radiation are becoming increasingly common.The objective of this work was to characterize thermoluminescent materials for the dosimetry of workers exposed to high doses. Samples of TLD-200, TLD-400 and TLD-800 pellets from Thermo Electron Corporation were studied in gamma high-doses. Dose-response curves were obtained for doses between 100 mGy and 100 Gy. The reproducibility, the lower detection limits and dose-response curves were obtained for all three materials. The different kinds of detectors show usefulness for dosimetry of workers exposed accidentally to high doses. (author)

Thermoluminescence, a universal tool for dosimetry

International Nuclear Information System (INIS)

Barthe, J.

1999-01-01

Radio-thermoluminescence is a transient light emission occurring when certain substances, which have been exposed to ionizing radiation, are heated. Under some conditions the quantity of emitted light is proportional to the absorbed dose. This linearity allows thermoluminescence to be used in various fields such as dosimetry, geology and age determination. Dosimeters based on thermoluminescence are passive, they do not require a source of energy and they can sustain high temperatures and high levels of irradiation. Thermoluminescence has been applied for determining the dose absorbed by meteorites and lunar rocks

Thermoluminescence dating of pottery

International Nuclear Information System (INIS)

Higashimura, Takenobu; Ichikawa, Yoneta.

1978-01-01

This report is divided into two parts. The first half describes on the history of thermoluminescence dating, and the latter half, the principle and measurement examples. It was in late 1955 that the measurement of radiation dose using thermoluminescence began. The method to thermoluminescence dating was developed when it was found that most natural stones emit the thermoluminescence. About Greek earthen wares, the study of which was presented in 1961 by G. Kennedy of University of California, the dating was able to be made within the standard deviation of 10%. Since then, this dating method progressed rapidly, and a number of laboratories are now forwarding the investigation. In the samples of natural materials, intensity of thermoluminescence I is proportional to natural radiation dose D which has been absorbed by the samples, i.e. I = kD, where k is the susceptibility of thermoluminescence of the samples. Since k is different in each sample, D can be determined by irradiating the sample with β or γ ray of known dose D 0 , measuring its luminescence I 0 , and eliminating k through these two equations, because i 0 = kD 0 . Next, if t is assumed to be the time passed since a pottery was made, D is expressed as Rt, where R is the natural radiation dose per year absorbed by the pottery. Thus t is determined if R is known. The report describes on the method of measuring R. As an example, the results of measurement of the potteries excavated at Iwakura remains, Yorikura, Taishaku-kyo, are listed. Results by 14 C dating are also described for reference. (Wakatsuki, Y.)

Method for detecting radiation dose utilizing thermoluminescent material

International Nuclear Information System (INIS)

Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Durham, J.S.

1992-01-01

The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light. 5 figs

Nuclearites search with the TLS detector

International Nuclear Information System (INIS)

Liang, S.; Wada, T.; Nakatsuka, T.; Okei, K.; Saavedra, O.; Takahashi, N.; Tsuji, S.; Yamamoto, I.; Yamashita, Y.; Lan, S.; Okita, M.; Takahashi, N.; Morita, T.; Ishii, R.; Goto, Y.; Iyono, A.; Matsumoto, H.; Nakagawa, M.; Noda, C.; Masuda, M.

2008-01-01

It is shown that a thermoluminescent sheet stack (TLS) detector, consisting of TL sheets and medical x-ray films, is an effective nuclearite detector. The TLS can be used for searching lighter nuclearites at sea level owing to the fact that the usual relativistic particles cannot make their tracks in the TLS unless they have a charge of larger than 50. We will report recent results of searching for lighter nuclearites at sea level

Thermoluminescent system for low temperatures

International Nuclear Information System (INIS)

Rosa, L.A.R. da; Caldas, L.V.E.; Leite, N.G.

1988-09-01

A system for measurements of the thermoluminescent glow curve, the thermoluminescent emission spectrum and the optical absorption spectrum of solid samples, from liquid nitrogen temperature up to 473 K, is reported. A specially designed temperature programmer provides a linear heating of the sample at a wide range of selectable heating rates, as also long term steady-state temperatures for annealing and isothermal decay studies. The system operates at a pressure of 1.33 x 10 -3 Pa. Presently it is being used for lithium fluoride low temperature thermoluminescent studies. (author) [pt

Preparation of thermoluminescent materials

International Nuclear Information System (INIS)

1976-01-01

Thermoluminescent materials have been found to be suitable for measuring long term exposures to low level ionizing radiation. Oxyhalides of lanthanum, gadolinium and yttrium, including the oxychlorides and oxybromides are activated with terbium and have been found to be most efficient oxygendominated phosphors having thermoradiant efficiencies with excitation by low level ionizing radiation. Thermoluminescence response increases when the previous materials have hafnium and zirconium additives

Characteristics for heavy ions and micro-dosimetry in radiation detectors

International Nuclear Information System (INIS)

Doke, Tadayoshi

1978-01-01

The characteristics of radiation detectors for heavy ions generally present more complex aspects as compared with those for electron beam and γ-ray. There is the ''Katz theory'' applying the target theory in radiobiology phenomenologically to radiation detectors. Here, first, the Katz theory for radiation detectors is explained, then its applications to nuclear plates, solid state track detectors, scintillation detectors and thermoluminescence dosimeters are described, respectively. The theory is used for the calibration of the nuclear charge of heavy ions in nuclear plates and recently is used to simulate the flight tracks of heavy ions or magnetic monopoles. In solid state track detectors, the threshold value of the energy given along the tracks of heavy ions is inherent to a detector, and the Katz theory is applicable as the measure of the threshold. The theory seems to be superior to the other methods. However, it has disadvantages that the calculation is not simple and is difficult for wide objects. In scintillation detectors, the scintillation efficiency is not a single function of dE/dx, but depends on the kinds of heavy ions, which Katz succeeded to describe quantitatively with his theory. Such result has also been produced that the dependence of thermoluminescence dosimeters such as LiF on LET by Katz theory agreed fairly well with experiments. (Wakatsuki, Y.)

Selected references on thermoluminescent dosemeters for personnel monitoring

International Nuclear Information System (INIS)

Lawson, Helen

1976-08-01

This bibliography contains references on: specific thermoluminescent dosemeters used for personnel dosimetry; comparisons of thermoluminescent and other dosemeters for personnel monitoring and read-out apparatus for thermoluminescent dosemeters. An appendix contains selected foreign language references. (author)

Thermoluminescence: its understanding and applications

International Nuclear Information System (INIS)

Nambi, K.S.V.

1977-01-01

The phenomenon of thermoluminescence is treated exhaustively both mathematically and physically. All the possible applications of the phenomenon are briefly described and an optimistic picture of the future trends in this field is projected. A review of latest information on thermoluminescence instrumentation and phosphors is also included [pt

New thermoluminescence techniques for mineral exploration

International Nuclear Information System (INIS)

Levy, P.W.; Holmes, R.J.; Ypma, P.J.; Chen, C.C.; Swiderski, H.S.

1977-01-01

The thermoluminescence of carbonate host rock in the vicinity of known lead-zinc and lead-zinc-fluorite mineralization was reexamined for possible development as an exploration technique. The measurements were made with equipment for determining the thermoluminescence spectrum at closely spaced temperature intervals. Radiation-induced thermoluminescence was also measured. Samples were studied from five localities in Mexico, Southwest Africa, and the United States. Four thermoluminescence properties were found to vary with ''distance-from-ore'' in a systematic manner. These include the glow peak intensity and temperature and the emission spectrum peak energy and full width at half-maximum. For example, in both limestone and dolomite, the high-temperature glow peak intensities are low or negligible within the ore and as the distance from the contact increases the intensity rises rapidly to a maximum, or maxima, and then decreases irregularly to constant value slightly above that in the ore. Depending on the thickness of the ore, the thermoluminescence characteristics associated with the mineralization extended from ten to a hundred or so meters from the ore host rock contact. 5 figures

Values of dose and individual of a individual thermoluminescent dosimeter submitted to x and gamma radiations

International Nuclear Information System (INIS)

Moraes, Cassiana Viccari de; Pela, Carlos Alberto

2001-01-01

The individual monitoring provides information for the control of exposures, and estimates the dose received by individuals. This is an essential tool in personal dosimetry. It's based on a radiation protection concept, allowing an individual exposure control, besides guaranteeing that the dose restrictions will not be exceeded. Usually, the dose monitoring is performed by using an individual dosemeter placed on a representative position of the most exposed point on the thoracic surface. The dosemeter, which is analyzed in the present work, is made of three CaSO 4 -Dy thermoluminescent detectors, plastic filters, copper and copper-lead, mounted in an acrylic support. The dose received by on each detector, which forms the dosemeter, is related according to their energetic curve dependence. The dose amount is calculated from these curves by using an algorithm, and it was taken in to consideration the detector calibration and thermoluminescent responses, due to the x and g radiation exposure. That algorithm has the capacity to determine the energies that were irradiated the detector. Therefore, to aid the service in the moment of evaluate the dose received by the individual and where it is coming from. The algorithm has provided individual dose value H x , defined as operational quantity for photons adopted in the Brazilian Metric System. The algorithm can determine two dose values and such values have been analyzed according to the kind of irradiated energy on the dosimeter and it has shown that both values are within established limits by Instituto de Radioprotecao e Dosimetria (IRD). (author)

Thermoluminescent Signals Caused by Disturbing Effects

International Nuclear Information System (INIS)

German, U.; Weinstein, M.; Ben-Shachar, B.

1999-01-01

One of the major sources of uncertainty in the measurement of low radiation doses by means of thermoluminescence dosemeters is the presence of disturbing thermoluminescence signals, especially luminescence caused by visible light, and by materials attached to the heated areas. Glow curves of thermoluminescence dosemeters contain useful information that can improve the accuracy and the reliability of the thermoluminescent measurements. The influence of the various disturbing effects can be recognised in the shape of the glow curves and can sometimes be separated from the exposure. Some examples are presented of signals arising from the two disturbing effects mentioned above, the signal contributed by Teflon used in the TLD-100 cards of Bicron/Harshaw and some abnormal glow curves due to dirt attached to the cards. Subtraction of the contributions due to these effects is suggested to obtain the net exposure signal. (author)

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

International Nuclear Information System (INIS)

Fernandez, F.

2009-10-01

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

Personnel radiation monitoring by thermoluminescence dosimetry (2000-2001)

International Nuclear Information System (INIS)

Mi-Cho-Cho, Daw; Hla-Hla-Win, Daw; Thin-Thin-Kraing

2001-01-01

Thermoluminescence dosimetry service was introduced in 1991. Personnel who exposed directly or indirectly to radiation is monitored by thermoluminescent dosimeter. TL materials used for thermoluminescent dosimeter are in the form of thin disc. Personnel whole-body and extremity doses are measured by thermoluminescence dosimetry. The Harshaw Model 4500 TLD reader and Vinten 654E TLD reader are used for TLD evaluation. At present about 600 radiation workers are provided with TLD for routine monitoring. It was found that most personnel had received within permissible dose recommended by the International Commission on Radiological Protection (ICRP). (author)

Reactor Gamma Heat Measurements with Calorimeters and Thermoluminescence Dosimeters

DEFF Research Database (Denmark)

Haack, Karsten; Majborn, Benny

1973-01-01

Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than calorimet......Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than...... calorimeters, but possess advantages such as a small probe size and the possibility of making simultaneous measurements at many different positions. Hence, thermoluminescence dosimeters may constitute a valuable supplement to calorimeters for reactor γ-ray heating measurements....

Thermoluminescence dosimetry in very hot atmosphere with a view to the dosimetry in nuclear reactors

International Nuclear Information System (INIS)

Bikwaku, Nsampala Tomakunsimba

1985-01-01

In order to develop radiation resistant materials for use in the region of nuclear reactor cores, it is necessary to know the dose absorbed by the surrounding structures. A passive thermoluminescence technique was chosen, an activated alumina material with very deep traps which are stable at high temperature (450 deg. C), being used. The characteristic properties of this detector have been studied and an attempt made to interpret the results obtained. (author) [fr

Absorbed dose from a beta source as shown by thermoluminescence dosimetry

International Nuclear Information System (INIS)

Wintle, A.G.; Aitken, M.J.

1977-01-01

The depth-dose curve was obtained for a 90 Sr- 90 Y beta source using a fine grain TL phosphor to measure the observed dose, aluminium absorbers being interposed between the source and the detector; the curve went through a maximum at an absorber thickness of about 40 mg cm -2 . This curve was then used to predict the average dose rate to various thicknesses of calcium fluoride which has a similar absorption characteristic to aluminium; these values were compared with experimentally determined dose rates. This work was done in connection with thermoluminescence dating of flint and calcite in archaeology and geology. (author)

Thermoluminescent response of LaAlO3:Pr

International Nuclear Information System (INIS)

Morales H, A.; Zarate M, J.; Azorin N, J.; Rivera M, T.

2015-10-01

In this study, the thermoluminescence response of doped lanthanum aluminate (LaAlO 3 ) with praseodymium ion (Pr) obtained by the Pechini method and drying by the spraying technique Spry Dryer was studied. The obtained powders were analyzed structurally by the X-ray diffraction technique; the morphological characterization was by the scanning electron microscopy technique. The obtained powders at 800 degrees C presented crystallinity and showed a Rhombohedral crystal structure, this phase was observed by X-ray diffraction patterns. Thermoluminescence response of LaAlO 3 :Pr showed a brightness curve with a peak centered at 157 degrees C. The sensitivity of the doped samples was improved about 90 times in comparison with the undoped sample. Thermoluminescence response in function of the wavelength showed a maximum at 230 nm, reproducibility of thermoluminescence response was ±50%. Also the fading in thermoluminescence response was studied. (Author)

Assessment of CaSO4:Dy and LiF:Mg,Ti thermoluminescent dosimeters performance in the dosimetry of clinical electron beams

International Nuclear Information System (INIS)

Nunes, Maira Goes

2008-01-01

The assessment of the performance of CaS0 4 :Dy thermoluminescent detectors produced by IPEN in the dosimetry of clinical electron beams aims to propose an alternative to the LiF:Mg,Ti commercial dosimeters (TLD-100) largely applied in radiation therapy. The two types of thermoluminescent dosimeters were characterised with the use of PMMA, RMI-457 type solid water and water phantoms in radiation fields of 4, 6, 9, 12 and 16 MeV electrons of nominal energies in which the dose-response curves were obtained and the surface and depth doses were determined. The thermoluminescent response dependency with the electron nominal energies and the applied phantom were studied. The CaS0 4 :Dy presented the same behaviour than the LiF:Mg,Ti in such a way that its application as an alternative to the TLD-100 pellets in the radiation therapy dosimetry of electron beams is viable and presents the significantly higher sensitivity to the electron radiation as its main advantage. (author)

Thermoluminescent measurement in space radiation dosimetry

International Nuclear Information System (INIS)

Chen Mei; Qi Zhangnian; Li Xianggao; Huang Zengxin; Jia Xianghong; Wang Genliang

1999-01-01

The author introduced the space radiation environment and the application of thermoluminescent measurement in space radiation dosimetry. Space ionization radiation is charged particles radiation. Space radiation dosimetry was developed for protecting astronauts against space radiation. Thermoluminescent measurement is an excellent method used in the spaceship cabin. Also the authors mentioned the recent works here

Assessment of CaSO{sub 4}:Dy and LiF:Mg,Ti thermoluminescent dosimeters performance in the dosimetry of clinical electron beams; Avaliacao do desempenho dos detectores termoluminesncetes de CaSO{sub 4}:Dy e LiF:Mg,Ti na dosimetria de feixes clinicos de eletrons

Energy Technology Data Exchange (ETDEWEB)

Nunes, Maira Goes

2008-07-01

The assessment of the performance of CaS0{sub 4}:Dy thermoluminescent detectors produced by IPEN in the dosimetry of clinical electron beams aims to propose an alternative to the LiF:Mg,Ti commercial dosimeters (TLD-100) largely applied in radiation therapy. The two types of thermoluminescent dosimeters were characterised with the use of PMMA, RMI-457 type solid water and water phantoms in radiation fields of 4, 6, 9, 12 and 16 MeV electrons of nominal energies in which the dose-response curves were obtained and the surface and depth doses were determined. The thermoluminescent response dependency with the electron nominal energies and the applied phantom were studied. The CaS0{sub 4}:Dy presented the same behaviour than the LiF:Mg,Ti in such a way that its application as an alternative to the TLD-100 pellets in the radiation therapy dosimetry of electron beams is viable and presents the significantly higher sensitivity to the electron radiation as its main advantage. (author)

Thermoluminescence from natural calcites

International Nuclear Information System (INIS)

Calderon, T.; Jaque, F.; Coy-yll, R.

1984-01-01

Thermoluminescence (TL) as well as absorption and EPR spectra of x-irradiated natural calcites have been obtained. Irradiation produces UV absorption bands and a decrease of the Mn 2+ EPR spectrum. A correlation of each TL peak with the bleaching steps of UV absorption bands and the recovering in intensity of the Mn 2+ EPR spectrum has been found. These experimental results support a new model for the radiation damage and thermoluminescence process in calcites. The main point in this model is that holes become trapped at impurities, and the electrons are trapped at dislocations in the form of CO 3 3- . (author)

Characteristic of 120 degree C thermoluminescence peak of iceland spar

International Nuclear Information System (INIS)

Lu Xinwei; Han Jia

2006-01-01

The basic characteristic of 120 degree C thermoluminescence peak of iceland spar was studied. The experimental result indicates the longevity of 120 degree C thermoluminescence peak of iceland spar is about 2 h under 30 degree C. The thermoluminescence peak moves to the high temperature when the heating speed increasing. The intensity of 120 degree C thermoluminescence peak of iceland spar is directly proportional to radiation dose under 15 Gy. (authors)

Thermoluminescence dependence on the wavelength of monochromatic UV-radiation in Cu-doped KCl and KBr at room temperature

Energy Technology Data Exchange (ETDEWEB)

Perez R, A.; Piters, T.; Aceves, R.; Rodriguez M, R.; Perez S, R., E-mail: rperez@cifus.uson.mx [Universidad de Sonora, Departamento de Investigaciones en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

2014-08-15

Thermoluminescence (Tl) dependence on the UV irradiation wavelengths from 200 to 500 nm in Cu-doped KCl and KBr crystals with different thermal treatment has been analyzed. Spectrum of the Tl intensity of each material show lower intensity at wavelengths longer than 420 nm. The Tl intensity depends on the irradiation wavelength. Structure of the Tl intensity spectrum of each sample is very similar to the structure of its optical absorption spectrum, indicating that at each wavelength, monochromatic radiation is absorbed to produce electronic transitions and electron hole pairs. Thermoluminescence of materials with thermal treatment at high temperature shows electron-hole trapping with less efficiency. The results show that Cu-doped alkali-halide materials are good detectors of a wide range of UV monochromatic radiations and could be used to measure UV radiation doses. (Author)

Thermoluminescence dependence on the wavelength of monochromatic UV-radiation in Cu-doped KCl and KBr at room temperature

International Nuclear Information System (INIS)

Perez R, A.; Piters, T.; Aceves, R.; Rodriguez M, R.; Perez S, R.

2014-08-01

Thermoluminescence (Tl) dependence on the UV irradiation wavelengths from 200 to 500 nm in Cu-doped KCl and KBr crystals with different thermal treatment has been analyzed. Spectrum of the Tl intensity of each material show lower intensity at wavelengths longer than 420 nm. The Tl intensity depends on the irradiation wavelength. Structure of the Tl intensity spectrum of each sample is very similar to the structure of its optical absorption spectrum, indicating that at each wavelength, monochromatic radiation is absorbed to produce electronic transitions and electron hole pairs. Thermoluminescence of materials with thermal treatment at high temperature shows electron-hole trapping with less efficiency. The results show that Cu-doped alkali-halide materials are good detectors of a wide range of UV monochromatic radiations and could be used to measure UV radiation doses. (Author)

Numerical analysis of thermoluminescence glow curves

International Nuclear Information System (INIS)

Gomez Ros, J. M.; Delgado, A.

1989-01-01

This report presents a method for the numerical analysis of complex thermoluminescence glow curves resolving the individual glow peak components. The method employs first order kinetics analytical expressions and is based In a Marquart-Levenberg minimization procedure. A simplified version of this method for thermoluminescence dosimetry (TLD) is also described and specifically developed to operate whit Lithium Fluoride TLD-100. (Author). 36 refs

Personal radiation monitoring with thermoluminescent dosemeters

International Nuclear Information System (INIS)

Miano, S.C.

1987-01-01

The technique of personal dosimetry used by SAPRA (Servico de Assessoria e Protecao Radiologica S/C Ltda., Brazil) is presented. Thermoluminescent monitors and CaSO 4 : Dy are used in pastilles united by teflon. Characteristics of the dosemeters are briefly reported. The system of thermoluminescent measurement, designed and constructed by SAPRA, and the system of personal monitoring are described. (M.A.C.) [pt

Clay as Thermoluminescence Dosemeter in diagnostic Radiology ...

African Journals Online (AJOL)

This paper reports the investigation of the basic thermoluminescence properties of clay at x-rays in the diagnostic radiology range, including dose monitoring in abdominal radiography. Clay sourced from Calabar, Nigeria, was tested for thermoluminescence response after irradiation at diagnostic radiology doses, including ...

Radiation detectors as surveillance monitors

International Nuclear Information System (INIS)

Fehlau, P.E.; Dowdy, E.J.

1981-01-01

The International Atomic Energy Agency (IAEA) proposes to use personnel dosimetry radiation detectors as surveillance monitors for safeguards purposes. It plans to place these YES/NO monitors at barrier penetration points declared closed under IAEA safeguards to detect the passage of plutonium-bearing nuclear material, usually spent fuel. For this application, commercially available dosimeters were surveyed as well as other radiation detectors that appeared suitable and likely to be marketed in the near future. No primary advantage was found in a particular detector type because in this application backgrounds vary during long counting intervals. Secondary considerations specify that the monitor be inexpensive and easy to tamper-proof, interrogate, and maintain. On this basis radiophotoluminescent, thermoluminescent, and electronic dosimeters were selected as possible routine monitors; the latter two may prove useful for data-base acquisition

Thermoluminescent analysis of CaSO{sub 4} composites activated with rare earths; Analise termoluminescente de compositos de CaSO{sub 4} ativado com terras raras

Energy Technology Data Exchange (ETDEWEB)

Junot, D.O.; Chagas, M.A.P.; Souza, D.N., E-mail: danilo.junot@hotmail.com, E-mail: mchagasfisica@gmail.com, E-mail: divanizi@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Fisica

2013-07-01

Since the thermoluminescence started to be applied to the dosimetry of ionizing radiation in 1940 different materials detectors have been proposed, and one of the most common is CaSO{sub 4}. The motivation of this work was to produce crystals of CaSO{sub 4} doped with rare earth elements such as europium (Eu), neodymium (Nd) and thulium (Tm). It was also produced crystals of CaSO{sub 4}:Ag. The interest in the production of these materials was to investigate other methods of production of thermoluminescent materials. The results show that the CaSO{sub 4}:Tm is more suitable for use in the thermoluminescent dosimetry. Although not the most intense peak, the peak at 170 °C could be a dosimetric peak. Analyses showed that all samples have a TL response proportional to the dose absorbed. (author)

Thermoluminescent dosimetry and assessment of personal dose

International Nuclear Information System (INIS)

Boas, J.F.; Martin, L.J.; Young, J.G.

1982-01-01

Thermoluminescence is discussed in terms of the energy band structure of a crystalline solid and the trapping of charge carriers by point defects. Some general properties of thermoluminescent materials used for dosimetry are outlined, with thermoluminescence of CaSO 4 :Dy being described in detail. The energy response function and the modification of the energy response of a dosimeter by shielding are discussed. The final section covers the connection between exposure, as recorded by a TLD badge, and the absorbed dose to various organs from gamma radiation in a uranium mine; the conversion from absorbed dose to dose equivalent; and uncertainties in assessment of dose equivalent

Investigations on low temperature thermoluminescence centres in quartz

International Nuclear Information System (INIS)

Bernhardt, H.

1984-01-01

The present paper will help to understand the often investigated process of thermoluminescence of quartz which is of high complexity. A lot of traps exist in quartz crystals which compete with each other with respect to the trapping of charge carriers during the X-ray treatment. That is why a variety of processes takes place after X-irradiation at liquid nitrogen temperature (LNT) of quartz which complicate the phenomenology of low temperature thermoluminescence. This competition in the trapping process leads to the so-called 'sensibilization' or 'desensibilization' effects of thermoluminescence, respectively, which are described in this paper for the first time. This effect means the dependence of the LNT thermoluminescence intensity on a pre-irradiation dose applied at room temperature (RT). The influence of this pre-irradiation is understood assuming the saturation of competitive traps. This favours an enhanced trapping of charge carriers at LNT-(shallow) traps instead of the preferential trapping on the deep traps in the case of X-ray treatment of the as-grown crystal at LNT. To get the afore mentioned model we take into account not only thermoluminescence but also coloration, ir- and vuv-absorption measurements. (author)

Dosimetric of extremities with Dosemeters thermoluminescent in Cuba

International Nuclear Information System (INIS)

Molina Perez, D.; Diaz Bernal, E.; Vera Alonso, L.

1998-01-01

From final of the year 1995 in the CPHR implement the service of monitoring of the extremities using Dosemeter thermoluminescent (TL). The dosemeter consists on a metallic ring with a circular hole where a detector of LiF:Mg,Ti is placed (model JR1152C) of 5x5x0.9 mm 3 , covered by a fine layer of polyethylene. In the work the characteristic dosimetric as of the dosemeter is studied it satisfies the main requirements for their use in the monitoring from the exhibition to radiation photonic of the extremities. The doses are also presented registered during the first two years of operation of the service. The results obtained until the moment point out to you practice them of nuclear medicine, radiotherapy and production of substances radioactive how as of more contribution

Phototransfered thermoluminescence for dose reassessment in LiF:mg,ti , LiF: mg,Cu,p TL detectors

International Nuclear Information System (INIS)

Rodriguez Otazo, M.; Baly, L.

2001-01-01

Phototransfered Thermoluminescence (PTTL) from LiF:Mg,Ti (TLD-100) and LiF: Mg,Cu,P (GR-200) was studied at different conditions using different sources of UV light for dose reassessment purposes. The TL dosimeters were irradiated with 137Cs in the range 2 mGy to 100 mGy. The convenience of using PTTL for dose reassessment was analyzed

Thermoluminescence of meteorites and their orbits

Science.gov (United States)

Melcher, C. L.

1981-01-01

The thermoluminescence levels of 45 ordinary chondrites are measured in order to provide information on the orbital characteristics of the meteorites before impact. Glow curves of the photon emission response of powdered samples of the meteorites to temperatures up to 550 C in the natural state and following irradiation by a laboratory test dose of 110,000 rad were obtained as functions of terrestrial age and compared to those of samples of the Pribram, Lost City and Innisfree meteorites, for which accurate orbital data is available. The thermoluminescence levels in 40 out of 42 meteorites are found to be similar to those of the three control samples, indicating that the vast majority of ordinary chondrites that survive atmospheric entry have perihelia in the range 0.8-1 AU. Of the remaining two, Farmville is observed to exhibit an unusually large gradient in thermoluminescence levels with sample depth, which may be a result of a temperature gradient arising in a slowly rotating meteorite. Finally, the thermoluminescence measured in the Malakal meteorite is found to be two orders of magnitude lower than control samples, which is best explained by thermal draining by solar heating in an orbit with a perihelion distance of 0.5 to 0.6 AU.

Dental tissue as a thermoluminescence dosimetry dosimeter

International Nuclear Information System (INIS)

Solaimani, F.; Zahmatkesh, M.H.; Akhlaghpoor, Sh.

2003-01-01

Background: Thermoluminescence dosimetry is one of the dosimetry procedures used widely as routine and personal dosimeters. In order to extend this kind of dosimeters, dental tissue has been examined and was found promising as a Thermoluminescence Dosimetry dosimeter. Materials and Methods: In this study, 70 health teeth were collected. The only criterion, wich was considered for selection of the teeth, was the healthiness of them regardless of age and gender of the donors. All collected samples were washed and cleaned and milled uniformly. The final powder had a uniform grain size between 100-300 micrometer. The sample was divided into four groups. Group A and B were used for measurement of density and investigation of variation of thermoluminescent characteristics with temperature respectively. Groups C and D were used for investigation of variation of thermoluminescent intensity with dose and fading of this intensity with time. In all cases the results obtained with dental tissue were compared to a standard LiF, thermoluminescence dosimetry dosimeter. Results: It was found that, average density of the dental tissue was 1.570 g/cm 3 , which is comparable to density of LiF, which is 1.612g/cm 3 . It was also concluded that the range of 0-300 d ig C , dental tissue has a simple curve with two specific peaks at 140 and 25 d ig C respectively. The experiment also showed that, the variation of relative intensity versus dose is linear in the range of 0.04-0.1 Gy. The fading rate of dental tissue is higher than LiF but still in the acceptable range (14% per month in compare to 5.2% per month). Conclusion: Dental tissue as a natural dosimeter is comparable with Thermoluminescence Dosimetry and can be used in accidental events with a good approximation

Thermoluminescence - physics and applications

International Nuclear Information System (INIS)

Sunta, C.M.

1992-01-01

The interaction of ionizing radiations with matter leads to various effects, some of which leave memory in the target material. These memory effects can be seen as the after-effects of the irradiation. Thermoluminescence is one such phenomenon in the insulating solids. This paper describes the sequence of the physical events beginning with the incidence of an ionizing particle, leading to a trail of atomic and electronic displacements which stabilize in the form of so called defect centres. These defects - interstitials, colour centres, etc., store energy in their configuration. Most of the damage effects are reversible. The return of the displaced entities to their original site leads to the release of the stored energy. Thermoluminescence is the result of the re-adjustment (relaxation) of the displaced electrons. The stimulation for the relaxation process is provided by heating of the irradiated sample. The kinetics of the thermoluminescence process has been explained phenomenologically. The correspondence between the defect centres and the TL glow peaks has remained vague or ambiguous even in the most widely studied TL materials. Notwithstanding this deficiency, the phenomenon has found many practical applications. The paper deals mainly with the physical processes involved in the TL emission and alludes briefly to its involvement in applied areas.(author). 6 refs., 2 figs

External dosimetry by Thermoluminescent Dosimetry Laboratory - IPEN/CNEN - Brazil

International Nuclear Information System (INIS)

Manzoli, Jose Eduardo; Carvalho, Ricardo Nunes

2001-01-01

The Thermoluminescence Dosimetry Laboratory, LDT - IPEN/CNEN - Brazil, executes around six thousand TLD readings monthly. It is responsible for the dose evaluation and registration and for all the manufacture process of preparation and sending the dosemeters which are used by IPEN itself, hospitals, industries, town halls, universities, etc. Although prepared to read many kinds of materials, actually the LDT reads only CaSO 4 :Dy detector chips. Chips, heating molds, plastic packaging and almost every material or instrument are made right here at IPEN. The readings are performed in a Bicron Harshaw TLD model 5500, but an old model 2000-AB is ready to be used if necessary. In this work it is presented some features of this important service realized to the IPEN workers and to the community. (author)

A technique for the assessment of the masses of residual plutonium in gloveboxes using thermoluminescent dosimeters

International Nuclear Information System (INIS)

Day, B.; Godward, D.F.

1979-01-01

A means of measuring the mass of residual plutonium in gloveboxes in the size range 1 to 10 m 3 has been developed using multiple thermoluminescent detectors. By optimising the location and the number of detectors, and by using suitable filtration, the mean response from them has been made insensitive to the distribution and the composition of the plutonium. It is possible to detect 10 g of plutonium in the largest glovebox considered. The measurement and mass estimation processes have been reduced to simple operations which can be carried out by skilled industrial staff. The routine application of the technique has been arranged to minimise disturbance to be production work going on in the gloveboxes by making unattended measurements during silent hours

A theoretical description of complex thermoluminescence curves: Pt. 1

International Nuclear Information System (INIS)

Kantorovich, L.N.; Fogel, G.M.; Gotlib, V.I.

1988-01-01

Thermoluminescence kinetics has been discussed within the framework of a band model assuming an extensive retrapping of charge carriers in comparison with their recombination. Assuming that a luminophor has one type of recombination centre and an arbitrary number of trapping centres we succeeded in analysing complex thermoluminescence curves with an arbitrary number of peaks. It has been shown for an elementary peak that its form almost coincides with the Randall-Wilkins curve, and its intensity is proportional to the square of the absorbed dose. The effect of both the processes of localised charge carriers accumulation (irradiation and isothermal decay) and their redistribution on trapping centres during the thermoluminescence process have been dealt with taking into account the form and intensity of the thermoluminescence peaks. (author)

ESTRATÉGIA DO DESENVOLVIMENTO URBANO COMO FATOR DETERMINANTE PARA O DESENVOLVIMENTO INDUSTRIAL SUSTENTÁVEL

Directory of Open Access Journals (Sweden)

Rúbia Tânia Welter

2016-11-01

Full Text Available Este artigo tem por objetivo identificar a estratégia do desenvolvimento urbano como fator do desenvolvimento industrial sustentável. Para alcançar este objetivo, foi realizada uma pesquisa documental e uma revisão histórico-bibliográfica de uma cidade, neste caso, a cidade de Joinville-SC. Foi realizado, também, um estudo sobre a evolução dos acontecimentos históricos da cidade pesquisada, como forma de estabelecer que estratégias adotadas interferiram neste processo de desenvolvimento. Como resultado, foram identificados os fatores estratégicos inerentes ou determinantes para o desenvolvimento industrial da cidade. Palavras-chave: Desenvolvimento urbano. Desenvolvimento industrial. Fatores estratégicos.

Thermoluminescence spectra measured with a Michelson interferometer

International Nuclear Information System (INIS)

Haschberger, P.

1991-01-01

A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium; Procesos opticos y termoluminiscentes en dosimetros de halogenuros alcalinos contaminados con Europio

Energy Technology Data Exchange (ETDEWEB)

Barboza F, M.; Melendrez, R.; Castaneda, B.; Pedroza M, M.; Chernov, V.; Perez S, R.; Aceves, R. [Centro de Investigacion en Fisica, Universidad de Sonora, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico)

2000-07-01

Recent research results are presented about the properties of the optical processes of photo transferred thermoluminescence (TLFT), optical whitening (BO), thermoluminescence induced by light (TLL) and its effect in the thermoluminescent curve (Tl) produced by ionizing and non-ionizing radiation. The systematic analysis of all these processes, acquires a singular importance due that actually the alkaline halogenide crystals are object of intense investigations which analyse their potential applications as detectors and radiation dosemeters through stimulated optical luminescence techniques or thermoluminescence. The obtained data show that the Tl curve of material with this nature can be enormously affected by exposure of phosphorus to the environmental light or UV. This is in part due to liberation processes of charge bearers are shouted and makes a subsequent trapping in less temperature traps; at the same time that induce changes in the intensity of determined Tl bands. Additionally, also it is observed that mentioned phenomena are related as with wavelength of incident light as of the illumination time. Finally, the obtained information allows to conclude that although the illumination effect is extremely complex, it is associated and can be explained mainly with phenomena that implicate the electrons excitation trapped in form of F centers and trapping mechanisms or radioactive and non-radioactive recombination. (Author)

Thermoluminescence in alkali halides irradiated at 80K

International Nuclear Information System (INIS)

Jimenez de Castro, M.

1978-01-01

The thermoluminescence, the thermally stimulated currents and the thermal stability of the F centres induced in pure NaCl and KC1 crystals by X irradiation at 80K have been studied in detail, in the range between 80 and 300K. The thermoluminescent processes induced by illumination at 80K with F light in samples previously irradiated at room temperature has also been studied. It has been clearly observed the existence of thermoluminescent processes due to electrons and holes thermally released from traps, in which the F centres are not involved. The existence of hole-F centre recombination has not been observed. There are several thermoluminescent processes in both materials which are scribed to the recombination of F centres with mobile interstitial halogen atoms thermally released from traps, which are likely monovalent impurities in this temperature interval. The light emitting stage in these processes is originated by the formation of self trapped excitons. (Author) 66 refs

Estimation of eye absorbed doses in head & neck radiotherapy practices using thermoluminescent detectors

Directory of Open Access Journals (Sweden)

Gh Bagheri

2011-09-01

Full Text Available  Determination of eye absorbed dose during head & neck radiotherapy is essential to estimate the risk of cataract. Dose measurements were made in 20 head & neck cancer patients undergoing 60Co radiotherapy using LiF(MCP thermoluminescent dosimeters. Head & neck cancer radiotherapy was delivered by fields using SAD & SSD techniques. For each patient, 3 TLD chips were placed on each eye. Head & neck dose was about 700-6000 cGy in 8-28 equal fractions. The range of eye dose is estimated to be (3.49-639.1 mGy with a mean of maximum dose (98.114 mGy, which is about 3 % of head & neck dose. Maximum eye dose was observed for distsnces of about 3 cm from edge of the field to eye.

Equipment for observing thermoluminescence

International Nuclear Information System (INIS)

Sette Camara, Alexandre; Cogneau, Michel; Ristori, Christian; Vargas, Jose Israel

1971-06-01

A detailed description is given of an apparatus for investigating thermoluminescence properties. Chopping of the emitted light and subsequent amplification of the electric signal derived led to high stability and sensitivity [fr

Radiation dosimetry for microbial experiments in the International Space Station using different etched track and luminescent detectors

Czech Academy of Sciences Publication Activity Database

Goossens, O.; Vanhavere, F.; Leys, N.; De Boever, P.; O'Sullivan, D.; Zhou, D.; Spurný, František; Yukihara, E.; Gaza, R.; McKeever, S.

2006-01-01

Roč. 120, 1- 4 (2006), s. 433-437 ISSN 0144-8420 R&D Projects: GA MŠk 1P05OC032 Institutional research plan: CEZ:AV0Z10480505 Keywords : bacteria l experiments * space flight * etched track detectors * thermoluminescent detectors Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.446, year: 2006

Study and determination of thermoluminescent properties of a new dosemeter based on α -Al2O3:C

International Nuclear Information System (INIS)

Rivera Montalvo, T.

1993-01-01

Study and determination of the thermoluminescent properties of a new dosimeter based on α -Al 2 O 3 :C. Dosimetric characteristics studied were: glow curve structure, sensitivity, reproducibility, TL response as function of dose, and fading. Each experimental data point represents the average value of at least five measurements. The new detectors exhibited two peaks in its glow curve at 383 and 493 K. The low temperature peak decayed at room temperature in a few hours. Sensitivity of α -Al 2 O 3 :C detectors to gamma radiation per unit of absorbed dose was 3 times that of LiF:Mg, Cu, P and 11 times that of CaSO 4 : Dy + PTFE; the last two detectors possess characteristics which make them appropriate for diverse applications in the field of radiation dosimetry, specially for environmental measurements. (Author)

Thermoluminescent phosphor

Science.gov (United States)

Lasky, Jerome B.; Moran, Paul R.

1978-01-01

A thermoluminescent phosphor comprising LiF doped with boron and magnesium is produced by diffusion of boron into a conventional LiF phosphor doped with magnesium. Where the boron dopant is made to penetrate only the outer layer of the phosphor, it can be used to detect shallowly penetrating radiation such as tritium beta rays in the presence of a background of more penetrating radiation.

Annual radiation dose in thermoluminescence dating

International Nuclear Information System (INIS)

Li Huhou

1988-01-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned

Annual radiation dose in thermoluminescence dating

Energy Technology Data Exchange (ETDEWEB)

Huhou, Li [Chinese Academy of Social Sciences, Beijing, BJ (China). Inst. of Archaeology

1988-11-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned.

Track etch and thermo luminescent detectors response to high energy charged particles

Czech Academy of Sciences Publication Activity Database

Spurný, František; Jadrníčková, Iva

2008-01-01

Roč. 43, Supp. 1 (2008), S169-S173 ISSN 1350-4487. [International Conference on Solids /23./. Beijing, 11.09.2006-15.09.2006] R&D Projects: GA ČR GA202/04/0795 Grant - others:Evropské společenství(XE) ILSRA - 2004 - 248 Institutional research plan: CEZ:AV0Z10480505 Keywords : track etch detector * thermoluminescent detectors * LET spectrometry Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.267, year: 2008

Intrinsic thermoluminescence of NaCl:Tl in UV dosimetry

International Nuclear Information System (INIS)

Barghare, S.P.; Joshi, R.V.; Joshi, T.R.; Kathuria, S.P.

1982-01-01

NaCl:Tl(T) phosphor is found to have high intrinsic thermoluminescence (TL) sensitivity to 253.7 nm UV-radiation. The dosimetric glow peak II grows sublinearly with increase in UV dose in the range 10 3 to 10 6 JM -2 . The other requirements of an efficient dosimeter material such as high storage stability, matching of the spectral response of detector tube and TL-emission from phosphor, reproducibility, desirable size and shape, easy availability in powder, pellet and crystal forms at cheaper rates, and repeated re-usability of the same phosphor without much difficulty, etc., are additional factors which strengthen the claim of NaCl:Tl(T) phosphor as UV dosimetric material. It is proposed that present NaCl:Tl(T) material is suitable TL-phosphor for UV dosimetry in the range 10 3 to 10 6 JM -2 . (author)

Application of thermoluminescence measurements to detect irradiated strawberries

International Nuclear Information System (INIS)

Heide, L.; Guggenberger, R.; Bogl, K.W.

1990-01-01

The thermoluminescence intensity of unirradiated and irradiated strawberries was studied with regard to dose response, storage time, and different varieties. An identification method could finally be developed. Further investigations were carried out to determine the origin of the thermoluminescence effect, which was found to be attributable to mineral grains adhering to the sample surface

Personnel monitoring of radiations with thermoluminescent dosemeters

International Nuclear Information System (INIS)

Miano, S.C.

1987-01-01

The basics of personnel dosimetry technics, used by the Radiologic Protetion and Assessorie Service (SAPRA) are presented, consisting on use of thermoluminescent and CaSO 4 :Dy monitors in aggregated pellets by Teflon. The characteristics of this dosemeters, relating to the sensitivity, energetic dependence, spike temperature, characteristic emission curve, decay and light effect are shown. The thermoluminescent dosemeter measure system and the personnel monitoring system are also described. (C.G.C.) [pt

MEIO AMBIENTE E DESENVOLVIMENTO

Directory of Open Access Journals (Sweden)

Suely Salgueiro Chacon

2009-12-01

Full Text Available O objetivo deste artigo é resgatar elementos para subsidiar uma reflexão crítica sobre o modelo de desenvolvimento econômico prevalente na sociedade e as relações com o meio ambiente, sob a ameaça que ronda o destino da espécie humana, conforme afirmação de Lovelock (2006, p. 20 sobre o conceito de desenvolvimento sustentável: “uma ideia adorável se a tivéssemos aplicado 200 anos atrás, quando havia um bilhão de pessoas no mundo. Agora é tarde demais. Não há mais espaço para nenhum tipo de desenvolvimento. A humanidade tem que regredir”. Este artigo apresenta a evolução do conceito de desenvolvimento econômico sob a ótica da sustentabilidade, e interliga temas como: o ambientalismo, aglutinador de distintos pensamentos sobre as relações entre a sociedade e a natureza; o movimento ambiental, a fundamentar a disseminação do conceito de desenvolvimento sustentável, e a gestão ambiental, abordada como prática orientada pelo conceito de desenvolvimento sustentável.

Thermoluminescent behavior of diamond thin films exposed to ultraviolet radiation

International Nuclear Information System (INIS)

Barboza F, M.; Gastelum, S.; Melendrez, R.; Chernov, V.; Bernal, R.; Cruz V, C.; Brown, F.

2002-01-01

In this work the thermoluminescent properties of diamond thin films are discussed which are grown up through the chemical vapor method exposed to ultraviolet radiation of 200-280 nm. The films with thickness 3, 6, 9, 12, 180 and 500 microns were grown up using a precursor gas formed of H 2 -CH 4 -CO excited through microwave energy or hot filament.The structure and morphology of the films were examined through scanning electron microscopy, indicating the formation of different diamond polycrystal structures which depend on the type of heating of the precursor gas used as well as the film dimensions. In general, the brilliance curve depends on the sample and the wavelength of the irradiation ultraviolet light, however it presents clearly thermoluminescence bands in 148, 160, 272, 304, 320 and 324 C degrees. The maximum of the thermoluminescence efficiency is obtained for the case of sample exposure with light of 214 nm. The sample of 500 microns is what exhibits greater thermoluminescent efficiency of those studied samples. The thermoluminescent behavior in function of radiation dose presents regions of linearity and supra linearity for higher and small doses respectively. The disappearance of the thermoluminescent signal depends on the characteristics of the film and it can reach until a 30 % of loss before to reach the stability. (Author)

Neutron dosimetry using activation of thermoluminescent CaSO 4

Science.gov (United States)

Azorín, Juan; Gutiérrez, Alicia

1984-11-01

Sulfur activation in calcium sulfate doped with dysprosium (CaSO 4:Dy) thermoluminescent powder, which is bound in pure sulfur, has been used to measure the fast neutron dose at the tangential beam port of a Triga Mark III reactor. After a post-irradiation time of 3 d, the dosimeters were annealed at 600°C for 30 min in order to erase all the thermoluminescence acquired during the irradiation. The dosimeters were then stored to allow self-irradiation by betas from 32P produced by sulfur activation. The thermoluminescent signal accumulated during a post-irradiation time of 20 d due to a neutron fluence of 2.2 × 10 11 n/cm 2 was equivalent to an absorbed dose of 10 mGy of 60Co gamma rays. The thermoluminescence as a function of fast neutron dose fitted to a straight line on a log-log scale from 1 Gy to 10 4Gy.

Calibration of Mg2SiO4(Tb) thermoluminescent dosimeters for use in determining diagnostic X-ray doses to Adult Health Study participants

International Nuclear Information System (INIS)

Kato, Kazuo; Antoku, Shigetoshi; Sawada, Shozo; Russell, W.J.

1989-11-01

Characteristics of Mg 2 SiO 4 (Tb) thermoluminescent dosimeters (TLD) were ascertained preparatory to measuring dose from diagnostic X-ray examinations received by Adult Health Study participants. These detectors are small, relatively sensitive to low-dose X rays, and are appropriate for precise dosimetry. Extensive calibration is necessary for precisely determining doses according to their thermoluminescent intensities. Their sensitivities were investigated, by dose according to X-ray tube voltage, and by exposure direction, to obtain directional dependence. Dosimeter sensitivity lessened due to the fading effect and diminution of the planchet. However, these adverse effects can be avoided by storing the dosimeters at least 1.5 hours and by using fresh silver-plated planchets. Thus, the TLDs, for which sensitivities were determined in this study, will be useful in subsequent diagnostic X-ray dosimetry. (author)

Kerma determination in air on mamma by thermoluminescence

International Nuclear Information System (INIS)

Palacios P, L. L.; Rivera M, T.

2009-10-01

In this work the experimental results of the entrance exposition are shown and Kerma in air [mGy] in mamma obtained by irradiation of accreditation phantom of American College of Radiology (ACR). The irradiations were realized in a conventional mammography equipment of Hospital Juarez in Mexico; the technique used during the irradiations was of automatic exposition; the thickness for the phantom ACR obtained by the technique were of 4.2 and 4.5 cm; the kilo voltage pick was of 24 kV p , the time and the milli amperage per second variable. The measuring of Kerma in air was obtained with thermoluminescent dosemeters of solid state, of nano particles of zirconium dioxide prepared by the precipitation method. The dosemeters were homogenized previously in low energies of X-rays that are those used for mammography. The thermoluminescent dosemeters of ZrO 2 were calibrated by means of an ionization chamber for different expositions. The calibration curve is reported for the exposition and Kerma in air against thermoluminescent intensity obtained by reading of thermoluminescent dosemeters of ZrO 2 , as well as the technique employee for the Kerma determination in air and entrance exposition in mamma. (Author)

Development of multiwire gas detectors for X-rays; Desenvolvimento de detectores a gas multifilares para raios-X

Energy Technology Data Exchange (ETDEWEB)

Sales, Eraldo de

2015-06-01

This work presents the prototype of a 2D position sensitive gas detector for application in X-ray scattering and diffraction experiments. Starting from a detector initially developed for other applications and will show the required changes on the original concept of this device. The strategy used to determine the necessary adaptations were based on searching in the literature for the overall characteristics of a multi-wire X-ray detector (choice of gas, pressure, window, etc.), the use of simulations, implementation of the changes and finally operational tests. Computational tools were used to calculate the mechanical strength and attenuation of the X-ray photons that helped to determine the most appropriate material for the construction of the entrance window. Detector simulations were built with Garfield software and were used to study the overall properties of the detector, and to determine the optimum parameters for the equipment operation. Typical parameters are the distance between the wires, wire diameter, high voltage to be used, among several other parameters. The results obtained showed that the multi-wire detector concept with the implemented adaptations allowed the detection of X-rays. However, depending on the application, it may be necessary improve the resolution of the equipment, in order to have a better description of the collected data. Several ideas are suggested for this improvement. It is also presented interesting results obtained with a microscopic pattern detector called triple GEM. This device belongs to the Gas Detectors Development group (GDD group) at CERN and was used in my training at this institution. The results showed the potential of the equipment for detection of X-rays. The results and simulations presented in this work, confirmed that the changes in the concept of the original detector permitted it use on X-ray detection applications. Also, it was possible to obtain several indications for further optimization, which may

Authenticity test in ceramics and archaeological figures by thermoluminescence

International Nuclear Information System (INIS)

Ramirez L, A.; Schaaf, P.; Filloy, L.

1999-01-01

At present exists quite a lot of false archaeological pieces which provokes doubts about the legitimacy of the pieces. In this work it is presented the Authenticity test by Thermoluminescence realized at the urn of the goddess 13 serpent of the zapotec culture of Oaxaca which is exposed in Mexico City. The original piece contains crystalline structures which present hardly the thermoluminescence phenomena by the presence of 238 U, 232 Th, and 40 K getting with this the form and intensity of the natural thermoluminescence curve of an archaeological piece which shows a Tl peak and allows to know so if it was made recently or not. (Author)

Dosimetric characteristics of radiation fields on board Czechoslovak Airlines' aircraft as measured with different active and passive detectors

International Nuclear Information System (INIS)

Spurney, F.; Obraz, O.; Pernicka, F.; Votockova, I.; Turek, K.; Vojtisek, O.; Starostova, V.

1993-01-01

Dosimetric characteristics on board Czechoslovak Airlines' aircraft (TU 154M; A310-300) were studied with different active and passive detectors (ionisation chamber RSS 112; scintillator based rate meter; GM counter based rate meter; neutron remmeter based on neutron moderation; thermoluminescence detectors, CR 39 track detectors and bubble-damage neutron detectors). Results obtained are analysed and discussed. It is estimated that the dose equivalent rates at altitudes of about 10 km are at least 3-4 μSv.h-1. Conclusions and recommendations for further studies and for radiation protection are given. (author)

Thermoluminescence of LiF: Mg, Ti between 77 and 315 K

International Nuclear Information System (INIS)

Rosa, L.A.R. da.

1989-01-01

A special thermoluminescent system was developed. It is able to operate right from liquid nitrogen temperature and also permits the determination of the sample thermoluminescent emission spectrum. Using this system, the thermoluminescence displayed by 77 K irradiated LiF:Mg,Ti (TLD-100), from the irradiation temperature to 315 K, was studied. In this temperature range seven glow peaks, at 139, 153, 194, 240, 260, 283 and 300 K, were determined. (author)

Thermoluminescence: Potential Applications in Forensic Science

Science.gov (United States)

Ingham, J. D.; Lawson, D. D.

1973-01-01

In crime laboratories one of the most difficult operations is to determine unequivocally whether or not two samples of evidence of the same type were originally part of the same thing or were from the same source. It has been found that high temperature thermoluminescence (room temperature to 723 K) can be used for comparisons of this type, although work to date indicates that there is generally a finite probability for coincidental matching of glass or soil samples. Further work is required to determine and attempt to minimize these probabilities for different types of materials, and to define more clearly the scope of applicability of thermoluminescence to actual forensic situations.

The thermoluminescent curve as parameter to compare archaeological ceramics

International Nuclear Information System (INIS)

Dominguez R, I.R.; Ramirez C, G.A.; Gonzalez M, P.R.; Mendoza A, D.; Martinez C, G.

2006-01-01

Most mineral materials, including the constituents of pottery, have the property of thermoluminescence (TL), where part of the energy from radioactive decay in the mineral is stored and later released as light upon strong heating. The intensity of emitted light as a function of temperature is the thermoluminescence glow curve. However, it is well-know the thermoluminescence glow curve form depends of several factors associates with the incident radiation and type of materials. Between the factors associated with the materials, it can be mentioned the quantity and type of crystalline phases, and quantity and type of impurities that they could be present in the material. That is to say, materials with different physicochemical characteristics will produce different thermoluminescence glow curve, although, they have been irradiated under the same conditions. In accordance with the above mentioned, it is possible to identified differences between pre hispanic ceramic belonging to a same site and other sites. In this work a discussion about advantages and disadvantages is presented. Some specific examples in ceramic artifacts belonging to the Matlatzinca and Teotihuacan cultures are included. (Author)

A study of the high-temperature signal characteristics in the thermoluminescence of porcelain

International Nuclear Information System (INIS)

Yin Gongming

2001-01-01

The thermoluminescence pre-dose technique for dating ancient porcelain was developed in many laboratories. This technique was the only method which could directly determine the age of old porcelain. But the thermoluminescence high-temperature signal (over 200 degree C) had not been studied. The authors conduced a preliminary study of the characteristic of thermoluminescence high-temperature signal, such as the TL natural glow curve, and the glow curves after beta or alpha irradiation. Most of the 32 ancient porcelains had thermoluminescence high temperature signal, and only one peak in their TL glow curve was found

Thermoluminescence of zirconium oxide nanostructured to mammography X-ray beams

International Nuclear Information System (INIS)

Palacios, L.L.; Rivera, T.; Roman, J.; Azorín, J.; Gaona, E.

2012-01-01

In the present work thermoluminescent (TL) response of zirconium oxide (ZrO 2 ) nanostructured induced by mammography X-ray radiation was investigated. Measurements were made of the response per unit air kerma of ZrO 2 with mammography equipment parameters (semiautomatic exposure control, 24 kVp and 108 mAs). The calibration curves were obtained by simultaneously irradiating ZrO 2 samples and ion chamber. Samples of ZrO 2 showed a linear response as a function of entrance skin air kerma. The observed results in TL properties suggest that ZrO 2 nanostructured could be considered as an effective material for X-ray beams dosimetry if appropriate calibration procedures are performed. - Highlights: ► X-ray low energy thermoluminescent of ZrO 2 dosimeter is developed. ► Air kerma measurements were made by thermoluminescent dosimeter ZrO 2 using mammography equipment parameters. ► Entrance surface skin doses were made using thermoluminescent dosimeter of ZrO 2 to X-ray beam quality control.

Review of surface dose detectors in radiotherapy

LENUS (Irish Health Repository)

O'Shea, E.

2006-11-20

Several instruments have been used to measure absorbed radiation dose under non-electronic equilibrium conditions, such as in the build-up region or near the interface between two different media, including the surface. Many of these detectors are discussed in this paper. A common method of measuring the absorbed dose distribution and electron contamination in the build-up region of high-energy beams for radiation therapy is by means of parallel-plate ionisation chambers. Thermoluminescent dosimeters (TLDs), diodes and radiographic film have also been used to obtain surface dose measurements. The diamond detector was used recently by the author in an investigation on the effects of beam-modifying devices on skin dose and it is also described in this report

γ radiation thermoluminescence performance of HFCVD diamond films

International Nuclear Information System (INIS)

Gastelum, S.; Cruz-Zaragoza, E.; Melendrez, R.; Chernov, V.; Barboza-Flores, M.

2006-01-01

Polycrystalline chemically vapor deposited (CVD) diamond films have been proposed as detectors and dosimeters of ionizing radiation with prospective applications in high-energy photon dosimetry applications. We present a comparison study on the thermoluminescence (TL) properties of two diamond film samples grown by the hot filament CVD method having thickness of 180 and 500 μm and exposed to γ radiation in the 1-300 Gy dose range. The 180 μm thick sample deposited on silicon substrate displayed a TL glow curve peaked at 145 deg. C. The 500 μm, which was a free standing sample, exhibited higher intensity and a well defined first order kinetics TL glow peak around 289 deg. C. Both diamond samples showed a linear dose behavior in the 1-50 Gy range and sublinear behavior for higher doses. The 180 and 500 μm samples presented about 80% and 30% TL losses in a 24 h period, respectively, with both samples showing excellent TL reproducibility. The results indicate that the 500 μm CVD diamond film exhibited a good TL behavior adequate for γ radiation dosimetry

Dose measurements in dental radiology using thermoluminescent dosimetry

International Nuclear Information System (INIS)

Chiara, Ana Claudia M. de; Costa, Alessandro M.; Pardini, Luiz Carlos

2009-01-01

The aim of this work was the implementation of a code of practice for dosimetry in dental radiology using the technique of thermoluminescent dosimetry. General principles for the use of thermoluminescent dosimeters were followed. The irradiations were performed using ten X-ray equipment for intra-oral radiography and an X-ray equipment for panoramic radiography. The incident air kerma was evaluated for five different exposure times used in clinical practice for intra-oral radiographs. Using a backscatter factor of 1.2, it was observed that approximately 40% of the entrance skin dose values found for intra-oral radiographs are above the diagnostic reference level recommended in national regulation. Different configurations of voltage and current were used representing the exposure as a child, woman and man for panoramic radiographs. The results obtained for the air kerma area product were respectively 53.3 +- 5.2 mGy.cm 2 , 101.5 +- 9.5 mGy.cm 2 and 116.8 +- 10.4 mGy.cm 2 . The use of thermoluminescent dosimetry requires several procedures before a result is recorded. The use of dosimeters with ionization chambers or semiconductors provides a simple and robust method for routine measurements. However, the use of thermoluminescent dosimetry can be of great value to large-scale surveys to establish diagnostic reference levels. (author)

Development of thermoluminescence dating techniques at Oxford

International Nuclear Information System (INIS)

Fleming, S.J.

1977-01-01

The two-decade long history of thermoluminescene as a pottery dating method is surveyed with particular reference to the various problems that have been encountered in the Oxford Laboratory's research programme. Effects, such as supralinearity and radon emanation, are explained in terms of how they are measured and how their existence influences thermoluminescence (TL) dating accuracy (currently close to plus minus 7% per analysis). Illustrations of Thermoluminescence (TL) applications include a Nok culture terracotta from Nigeria and a Cambodia bronze Buddha figure of the Khmer period, dated ising the ceramic-like casting-core retained within it. (author)

Re-use of radio-thermoluminescent LiF without regeneration; Reemploi sans regeneration du LiF radiothermoluminescent

Energy Technology Data Exchange (ETDEWEB)

Portal, G; Francois, H; Blanchard, Ph [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

There is at the present time a rapid development of dosimetry techniques using thermoluminescence. Amongst the many substance actually in use, research laboratories generally employ lithium fluoride which is of particular interest for dosing {beta} radiation and low-energy X and {gamma} radiation. It might also be of use in radioprotection if its practical application were simpler. It has in effect unstable traps situated just below the surface which adversely affect the measurements if the material is not regenerated before each operation; this process considerably complicates the carrying out of measurements in the field of radioprotection. We have prepared a lithium fluoride giving unstable peaks which are less pronounced that those of the commercially available product and which can therefore be used without regeneration. In this report we compare the thermoluminescence curves for these two products. An analysis is given of the reasons for which this radio-thermoluminescent product has a stable luminescence curve and can be used almost one hundred times without being regenerated. We show that this quality can be retained when the LiF is used as a filler for teflon for applications in detectors. (authors) [French] On assiste a un developpement rapide des techniques de dosimetrie par thermoluminescence. Parmi les nombreux materiaux actuellement utilises, les laboratoires de recherche font generalement porter leur preference sur le fluorure de lithium qui est particulierement interessant pour la dosimetrie des rayonnements {beta} et des rayonnements X et {gamma} de faible energie. Ses qualites seraient egalement appreciees en radioprotection si sa mise en oeuvre etait plus simple. Il presente en effet des pieges instables situes a une faible profondeur qui alterent les mesures si l'on ne procede pas, avant chaque utilisation, a la regeneration du materiau, operation qui alourdit considerablement les mesures pratiquees en radioprotection. Nous avons prepare un

Obtention of a thermoluminescent material for dosimetry of ionizing radiation

International Nuclear Information System (INIS)

Gonzalez M, P.R.

1990-01-01

The thermoluminescent dosemeters are small crystals which suffer changes in their structure by the radiation effect, being displaced the electrons toward higher energy levels. On heating the previously irradiated crystals, the electrons come back to their base state emitting light photons. The light quantity emitted is proportional to the received radiation dose. The light quantity emitted is proportional to the received radiation dose. The lithium fluoride is one of the thermoluminescent materials considered as tissue equivalents by having a low effective atomic number (Z ef ). At present, the more used commercial product used of this type is the TLD-100*. In this work the obtained results in the preparation of the lithium fluoride thermoluminescent material are presented. This is activated with magnesium (Mg) and titanium (Ti), which we have labelled as: LiF: Mg, Ti. The results from the tests performed for verifying his thermoluminescent properties are presented too, as powder form as in pellets form. These tests were performed in simultaneous form with TLD-100 samples, which is considered as reference. The LiF: Mg, Ti thermoluminescent material manufactured in the ININ presents similar dosimetric characteristics to those ones of the TLD-100. Therefore being able to replace the imported dosemeters. * (TLD-100 is a commercial trademark registered by Harshaw/Filtrol (US) for LiF: Mg, Ti Tl dosemeters) (Author)

Rapid assessment of accidental exposures (RACE) with MCP-N (LiF:Mg,Cu,P) detectors

International Nuclear Information System (INIS)

Budzanowski, M.; Bilski, P.; Olko, P.; Saez-Vergara, J.C.; Gomes-Ros, J.M.

1998-01-01

The system is based on a new generation of ultra-sensitive thermoluminescent dosemeters and is able to monitor environmental radiation doses at a large number of locations within few days and to perform rapid (24 - 48 hours) in situ dose assessment in the event of any nuclear or radiation accident. Technical specifications of the instrumentation and procedures of the system are given. The linearity of the detector response for doses within the range of 1 μGy to 1 Gy is better than 2%. All the detectors investigated demonstrated a good stability in long-term exposure. The detectors are fully comparable with active detectors in short-term and daily routine dose rate measurements. (M.D.)

Instrumentation in thermoluminescence dosimetry

International Nuclear Information System (INIS)

Julius, H.W.

1986-01-01

In the performance of a thermoluminescence dosimetry (TLD) system the equipment plays an important role. Crucial parameters of instrumentation in TLD are discussed in some detail. A review is given of equipment available on the market today - with some emphasis on automation - which is partly based on information from industry and others involved in research and development. (author)

Thermoluminescence of zirconium oxide nanostructured to mammography X-ray beams

Energy Technology Data Exchange (ETDEWEB)

Palacios, L.L. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria, IPN. Av. Legaria 694, 11500 Mexico D.F. (Mexico); Rivera, T., E-mail: trivera@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria, IPN. Av. Legaria 694, 11500 Mexico D.F. (Mexico); Roman, J. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria, IPN. Av. Legaria 694, 11500 Mexico D.F. (Mexico); Azorin, J. [Universidad Autonoma Metropolitana-Iztapalapa. Av. San Rafael Atlixco 187, 09340 Mexico D.F. (Mexico); Gaona, E. [Universidad Autonoma Metropolitana-Xochimilco. Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)

2012-07-15

In the present work thermoluminescent (TL) response of zirconium oxide (ZrO{sub 2}) nanostructured induced by mammography X-ray radiation was investigated. Measurements were made of the response per unit air kerma of ZrO{sub 2} with mammography equipment parameters (semiautomatic exposure control, 24 kVp and 108 mAs). The calibration curves were obtained by simultaneously irradiating ZrO{sub 2} samples and ion chamber. Samples of ZrO{sub 2} showed a linear response as a function of entrance skin air kerma. The observed results in TL properties suggest that ZrO{sub 2} nanostructured could be considered as an effective material for X-ray beams dosimetry if appropriate calibration procedures are performed. - Highlights: Black-Right-Pointing-Pointer X-ray low energy thermoluminescent of ZrO{sub 2} dosimeter is developed. Black-Right-Pointing-Pointer Air kerma measurements were made by thermoluminescent dosimeter ZrO{sub 2} using mammography equipment parameters. Black-Right-Pointing-Pointer Entrance surface skin doses were made using thermoluminescent dosimeter of ZrO{sub 2} to X-ray beam quality control.

Thermoluminescence properties of Yb-Tb-doped SiO2 optical fiber subject to 6 and 10 MV photon irradiation

Science.gov (United States)

Sahini, M. H.; Wagiran, H.; Hossain, I.; Saeed, M. A.; Ali, H.

2014-08-01

This paper reports thermoluminescence characteristics of thermoluminescence dosimetry 100 chips and Yb-Tb-doped optical fibers irradiated with 6 and 10 MV photons. Thermoluminescence response of both dosimeters increases over a wide photon dose range from 0.5 to 4 Gy. Yb-Tb-doped optical fibers demonstrate useful thermoluminescence properties and represent a good candidate for thermoluminescence dosimetry application with ionizing radiation. The results of this fiber have been compared with those of commercially available standard thermoluminescence dosimetry-100 media. Commercially available Yb-Tb-doped optical fibers and said standard media are found to yield a linear relationship between dose- and thermoluminescence signal, although Yb-Tb-doped optical fibers provide only 10 % of the sensitivity of thermoluminescence dosimetry-100. With better thermoluminescence characteristics such as small size (125 μm diameter), high flexibility, easy of handling and low cost, as compared to other thermoluminescence materials, indicate that commercial Yb-Tb-doped optical fiber is a promising thermoluminescence material for variety of applications.

Radiation induced defects and thermoluminescence mechanism in aluminum oxide

Energy Technology Data Exchange (ETDEWEB)

Atobe, K.; Kobayashi, T.; Awata, T. [Naruto Univ. of Education, Tokushima (Japan); Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Nakagawa, M. [Kagawa Univ., Faculty of Education, Takamatsu, Kagawa (Japan)

2001-01-01

The thermoluminescence of the irradiated aluminum oxides were measured to study the radiation induced defects and their behaviors. Neutron and {gamma}-ray irradiation were performed for a shingle crystal of the high purity aluminum oxide. The thermoluminescence glow curve and its activation energy were measured. The spectroscopy measurement on the thermoluminescence and the absorption are also carried out. The observed 430 and 340 nm peaks are discussed relating to the F{sup +} and F centers, respectively. Activation state of the F center transits to 3P state through 1P state by emitting phonons. Trapped electron on 3P state emits phonon of 2.9 eV (430 nm) during transition to the ground state. The above reaction can be written by the equation. F{sup +} + e {yields} (F){sup *} {yields} F + h{nu}(2.9 eV, 470 nm). (Katsuta, H.)

Dose-rate dependence of thermoluminescence response

International Nuclear Information System (INIS)

McKeever, S.W.S.; Chen, R.; Groom, P.J.; Durrani, S.A.

1980-01-01

The previously observed dose-rate effect of thermoluminescence in quartz at high dose-rates is given at theoretical formulation. Computer calculations simulating the experimental conditions yield similar results to the experimental ones. (orig.)

Study of some thermoluminescent phosphors for the dosimetry of ionizing radiations

International Nuclear Information System (INIS)

Jaafari, M.

1983-01-01

Thermoluminescence dosimetry techniques are reviewed and interactions radiation matter are recalled. The need for new phosphors is evidenced. Numerous phosphors are examined and calcium, strontium and barium sulfides are synthetized and deposited on glass supports. The thermoluminescence of the dosimeters obtained with these materials is analyzed [fr

Thermoluminescence properties of micro and nano structure hydroxyapatite after gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Shafaei, Mostafa; Ziaie, Farhood; Hajiloo, Nahid [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School

2016-12-15

The goal of this study is to compare the thermoluminescence properties of nano and micro structure hydroxyapatite. Nano structure hydroxyapatite was synthesized via hydrolysis method, while the micro structure one was from Merck Company. X-ray diffraction and fourier transform infrared spectroscopy were used to determine the crystal structure and chemical composition of the hydroxyapatite samples. Particles sizes of each sample were estimated using Scherer equation and transmission electron microscopy system. Thermoluminescence properties of the samples were investigated under gamma irradiation. The glow curves of micro and nano structure samples show a peak at 150 C and 200 C, respectively. Thermoluminescence responses of both the samples were linear in the range of 25 - 1 000 Gy where, nano structure sample show a greater slope and stronger linearity in comparison to the micro sample. The results show that the thermoluminescence response of micro sample faded rapidly in comparison to the nano sample due to the existence of the peak at higher temperature.

Thermoluminescence sensitivity variations in LiF PTFE dosemeters incurred by improper handling procedures

CERN Document Server

Mason, E W; MacKinlay, Alistair F; Saunders, D

1975-01-01

A systematic study of some anomalous darkening effects and thermoluminescence sensitivity variations observed in LiF:PTFE thermoluminescent dosemeters is described. Various likely causes of such effects have been investigated. The manufacturer's recommended cleaning procedures have been found to be inadequate and, in some cases, have been found to actually promote discolouration of the dosemeters. Recommendations are given for the successful use of LiF:PTFE thermoluminescent dosemeters in personal dosimetry.

Thermoluminescence of strontium tetraborate

International Nuclear Information System (INIS)

Santiago, M.; Caselli, E.; Lester, M.

1999-01-01

The thermoluminescent properties of crystalline strontium tetraborate are reported. Without activators it has an efficiency comparable to that of TLD-700 powder. Its fading after 40 days amount to less than 2%. The isometric plot shows that most of the emitted light is concentrated at wavelengths ranging from 350 to 450 nm, which accounts partially for the high efficiency. (author)

Variation in thermoluminescence of irradiated brands of foodstuffs: a test for hygienic quality

International Nuclear Information System (INIS)

Mamoon, A.; Zaheer, A.; Abu-Abdullah, S.

1996-01-01

Thermoluminescence of irradiated foodstuffs such as herbs and spices, is mostly due to attached dust or soil particles. Different brands of the same foodstuff sometimes give thermoluminescent signals of different intensities, apparently due to different degrees of dust contamination. It is of obvious importance to choose brands of foodstuffs that appear to have less dust contamination, i.e. of better hygienic quality. Several food items were investigated with respect to their thermoluminescent (TL) emission in order to assess TL usefulness as an indicator of hygienic quality for foods prone to contamination by dust. In this regard some foodstuff were artificially contaminated with a soil sample and their thermoluminescent emission was obtained. (author)

Thermoluminescence of Zn O thin films deposited by chemical bath

International Nuclear Information System (INIS)

Camacho A, M. C.; Cruz V, C.; Bernal H, R.; Berman M, D.; Castano M, V. M.

2015-10-01

Full text: Zn O films on Si were synthesized using a deposition method by chemical bath and thermally treated at 900 degrees C for 12 h in air. The morphological characterization by scanning electron microscopy reveals that uniform films were obtained. To investigate the thermoluminescent properties of the films were exposed to irradiation with beta particles with doses in the range from 0.5 to 128 Gy. The brightness curves obtained using a heating rate of 5 degrees C have two peaks, one at 124 and another at 270 degrees C, and a linear dependence of the integrated thermoluminescence as a function of dose. The second maximum reveals the existence of localized trapping states of potential utility in thermoluminescent dosimetry. (Author)

Thermoluminescent response of LiF before variation of the heating rate

International Nuclear Information System (INIS)

Barrios, R.; Avila, O.

2003-01-01

Comparisons of glow curves of lithium fluoride dosemeters TLD-100 measured to two heating rates with the purpose of quantifying the change in the temperature of the peaks 5 and 7 for the thermoluminescent reader equipment Harshaw 4000 of the thermoluminescence laboratory of the ININ were carried out. (Author)

Thermoluminescence of LaAlO{sub 3}; Termoluminescencia de LaAlO{sub 3}:Dy

Energy Technology Data Exchange (ETDEWEB)

Morales H, A.; Zarate M, J. [Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Investigacion en Metalurgia y Materiales, Ciudad Universitaria, Edif. U, 58060 Morelia, Michoacan (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Azorin N, J., E-mail: feyo_yo@hotmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

2015-10-15

In this paper the thermoluminescent properties of doped lanthanum aluminate (LaAlO{sub 3}) with dysprosium ion (Dy) were studied. The thermoluminescence characteristics in the samples were obtained using an ultraviolet radiation of 220 nm. The LaAlO{sub 3}:Dy samples were prepared by the modified Pechini method (Spray Dryer). The structural and morphological characterization was obtained by X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques respectively. The size particle composing the agglomerate was determined by Sem, agglomerated particles composed size of 2μm were observed. The thermoluminescence response of LaAlO{sub 3}:Dy was compared with that obtained with the undoped sample. Thermoluminescence brightness curves of LaAlO{sub 3}:Dy showed a peak centered at 185 grades C. Sensitivity of doped sample was greater, about 100 times compared with the undoped sample. Thermoluminescence response in function of the wavelength showed a maximum at 220 nm. Also the fading in thermoluminescence response was studied. (Author)

Food irradiation dosimetry using thermoluminescence of quartz sand

International Nuclear Information System (INIS)

Khan, H.M.; Ehlermann, D.A.E.

1993-01-01

Thermoluminescence of quartz sand, which is inert and concomitant to several food materials, has been investigated for applications in food irradiation dosimetry and detection of irradiated foods. The glow curves consist of at least three overlapping peaks from 100 to 420 C. The peak at lower temperature is not stable and decays quickly at room temperature. However, the peaks at higher temperature are stable and more useful for dosimetry work. The intensity of the peak at 360 C, measured using different optical filters, shows a linear response in the range of 0.05 to 23 kGy. Stability of these signals at different annealing temperatures has been investigated. Thermoluminescence from adhering minerals and contaminating dust in different food materials has been found useful for the detection of irradiation treatment. Since quartz is frequently one of these minerals, further computerized deconvolution of individual glow peaks from the complex glow curves of quartz sand was carried out which improves the dosimetric results. Possible applications of thermoluminescence of quartz sand in food irradiation dosimetry and detection of irradiated foods have been discussed. (orig.)

New color-photographic observation of thermoluminescence from sliced rock samples

International Nuclear Information System (INIS)

Hashimoto, Tetsuo; Kimura, Kenichi; Koyanagi, Akira; Takahashi, Kuniaki; Sotobayashi, Takeshi

1983-01-01

New observation technique has been established for the thermoluminescence photography using extremely high-sensitive color films. Considering future application to the geological fields, a granite was selected as a testing material. The sliced specimens (0.5--0.7 mm in thickness), which were irradiated with a 60 Co source, were mounted on the heater attached with a thermocouple, which was connected to a microcomputer for measuring the temperature. The samples were heated in the temperature range of 80--400 0 C by operating the camera-shutter controlled with the microcomputer. Four commercially available films (Kodak-1000(ASA), -400, Sakura-400, Fuji-400) could give apparently detectable color-images of artificial thermoluminescence above a total absorbed dose of 880 Gy(88 krad). The specimens, irradiated upto 8.4 kGy(840krad), allowed easily to distinguish the distinct appearance of the thermoluminescence images depending on kinds of white mineral constituents. Moreover, such color images were changeable with the heating temperature. Sakura-400 film has proved the most colorful images from aspects of color tone although Kodak-1000 film showed the highest sensitivity. By applying this Kodak-1000, it was found that the characteristic color image due to natural thermoluminescence was significantly observed on the Precambrian granite which was exposed with natural radiation alone since its formation. This simple and interesting technique, obtainable surface information reflecting impurities and local crystal defects in addition to small mineral constituents, was named as the thermoluminescence color imaging (abbreviated to TLCI) technique by the authors and its versatile applications were discussed. (author)

Thermoluminescent dosemeter in a X-ray diffractometer

International Nuclear Information System (INIS)

Mendoza A, D.; Gonzalez M, P.; Falcon B, T.; Castano, V.M.

1999-01-01

In this work it was presented the results obtained of the dosimetry which was realized in a X-ray diffractometer for powders, trademark Siemens D5000, using the thermoluminescent signal generated by the X-rays in the commercial dosemeter TLD-100 of Harshaw, US. In according to the results obtained, the radiation quantity received by an analysed material in the diffractometer, will be proportional to exposure time and it can vary from unities until tenths of grays. These results are very outstanding when are analysed crystalline materials in a diffractometer, for knowing the present crystalline phases, mainly if these are highly sensitive to the ionizing radiation, as it is the case of the thermoluminescent materials. (Author)

Thermoluminescence spectra of amethyst

Energy Technology Data Exchange (ETDEWEB)

Zhang, Q. [Suzhou Railway Teachers College (China). Dept. of Physics; Yang, B. [Beijing Normal University (China). Dept. of Physics; Wood, R.A.; White, D.R.R.; Townsend, P.D.; Luff, B.J. [Sussex Univ., Brighton (United Kingdom). School of Mathematical and Physical Sciences

1994-04-01

Thermoluminescence and cathodoluminescence data from natural and synthetic amethyst and synthetic quartz samples are compared. The spectra include features from the quartz host lattice and from impurity-generated recombination sites. Emission features exist throughout the wavelength range studied, 250-800 nm. The near infrared emission at 740-750 nm appears to be characteristic of the amethyst and is proposed to be due to Fe ion impurity. (Author).

Thermoluminescence kinetics of pyrite (FeS2)

International Nuclear Information System (INIS)

Silverman, A.N; Levy, P.W.; Kierstead, J.A.

1990-01-01

Thermoluminescence of pyrite (FeS 2 ) has been investigated to study the kinetics of single peak glow curves. The material used normally exhibits one large and four small peaks. However a glow curve can be obtained with only the large single peak that is suitable for testing thermoluminescence kinetics. Glow curves from aliquots of a single natural pyrite crystal studied in detail contain two low intensity thermoluminescence (TL) peaks at ∼90 degree and ∼250 degree C, and two chemiluminescence (CL) peaks at ∼350 degree and ∼430 degree C. The CL peaks are largely removable by initially heating the sample chamber under vacuum, pumping through liquid nitrogen traps, and recording glow curves immediately after helium is introduced, procedures which reduce system contaminants that react with pyrite. The shape, the variation of the temperature of the peak maximum (T max ) with dose, and the retrapping to recombination cross section ratio σ of the large 250 degree C peak are better described by the general one trap (GOT) kinetic equation, the basic equation from which the 1st and 2nd order kinetic equations are obtained as special cases (see text), than by the 1st and 2nd order equations. 12 refs., 7 figs

Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

International Nuclear Information System (INIS)

Braunlich, P.F.; Tetzlaff, W.

1989-01-01

Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters are disclosed. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phosphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate. 34 figs

Results obtained with the passive radiation detectors in the ICCHIBAN-4 experiment

International Nuclear Information System (INIS)

Bilski, P.; Horwacik, T.

2005-05-01

In frame of the InterComparison of Cosmic rays with Heavy Ions Beams at NIRS (ICCHIBAN) organized at the HIMAC accelerator in Chiba several types of the thermoluminescent detectors (TLD), as well as CR-39 track detectors, were exposed. Four different types of TLDs were used: MTS-7 ( 7 LiF:Mg,Ti), MTS-6 ( 6 LiF:Mg,Ti), MCP-7 ( 7 LiF:Mg,Cu,P) and MTT-7 ( 7 LiF:Mg,Ti with changed activator composition. All TLDs were manufactured at the Institute of Nuclear Physics (INP) in Cracow. The detectors were irradiated with various doses of He, C, Ne and Fe ions. Part of exposures were done in unknown conditions, to test measuring capabilities of the detectors. For analyses of these results, the method of obtaining information on ionisation density of an unknown radiation field, which is based on ratios of responses of different LiF detectors, was successfully used. (author)

Thermoluminescence studies on plant seeds of different radiosensitivity

International Nuclear Information System (INIS)

Yamaguchi, Hikoyuki; Eguchi, Hoshio; Koizumi, Yoshinobu.

1975-01-01

The thermoluminescence was found when the pulverized powders from the whole seeds of six plant species or the hypocotyls from the seeds of five soybean varieties were irradiated at a liquid nitrogen temperature with gamma-rays. The spectra of luminescence emitted, the light peak temperature, the decaying after irradiation and the dose relationship of luminescence were determined. A high yield of the rapidly-decaying luminescence occurred in the more radiosensitive variety when irradiated with relatively lower doses. The very drastic decrease of the thermoluminescence was observed in the samples irradiated at room temperature prior to the exposure at 77 0 K. (auth.)

Influence of thermoluminescence signal for debris flow surface materials by sunlight bleaching

International Nuclear Information System (INIS)

Song Bo; Wei Mingjian; He Youbing; Zhou Rui; Zhao Qiuyue; Zhang Bin

2013-01-01

Thermoluminescence was utilized for measuring the thermoluminescence signals of the standard debris flow samples which were bleached by simulated sunlight and debris flow samples after real sunlight bleaching. The experiment results demonstrate that light bleaching phenomenon of the debris flow occurs when it experiences a period of exposure. The thermoluminescence signal of the samples weakens gradually with the increase of depth. The optical bleaching phenomenon is obvious. Within a certain depth, light bleaching phenomenon is enhanced with the increase of light intensity. The annealing depth of simulated sunlight bleaching experiment is about 1 mm, and the actual annealing depth of sunlight bleaching is about 6 mm. According to the equivalent dose variation with depth, the mud of natural debris flow can be divided into two stages. It has fundamental significance in the application of thermoluminescence dating techniques to divide the stages of debris flow sediments. (authors)

Monitoring on board spacecraft by means of passive detectors

International Nuclear Information System (INIS)

Ambrozova, I.; Brabcova, K.; Spurny, F.; Shurshakov, V. A.; Kartsev, I. S.; Tolochek, R. V.

2011-01-01

To estimate the radiation risk of astronauts during space missions, it is necessary to measure dose characteristics in various compartments of the spacecraft; this knowledge can be further used for estimating the health hazard in planned missions. This contribution presents results obtained during several missions on board the International Space Station (ISS) during 2005-09. A combination of thermoluminescent and plastic nuclear track detectors was used to measure the absorbed dose and dose equivalent. These passive detectors have several advantages, especially small dimensions, which enabled their placement at various locations in different compartments inside the ISS or inside the phantom. Variation of dosimetric quantities with the phase of the solar cycle and the position inside the ISS is discussed. (authors)

Synthesis and thermoluminescence properties of CaF2:Tm,Ce nanoparticles

Directory of Open Access Journals (Sweden)

M Zahedifar

2013-10-01

Full Text Available Calcium fluoride nanoparticles doped with thulium and cerium were synthesized as a novel nanostructure by using the hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD and energy dispersive spectrometer (EDS. The crystallite size of about 36 nm was estimated employing Scherer’s formula. Its shape and size were also observed by scanning electron microscope (SEM. Computerized glow curve deconvolution (CGCD technique revealed two overlapping thermoluminescence glow peaks at around 402 and 457 K in the complex thermoluminescence glow curve of this phosphor. Other thermoluminescence characteristics of this phosphor such as fading, reuseability and dose response recommend it as a good candidate for high dose dosimetry.

Relationship between thermoluminescence and X-ray induced luminescence in alkali halides

International Nuclear Information System (INIS)

Aguilar, M.; Lopez, F.J.; Jaque, F.

1978-01-01

The wavelength spectra of thermoluminescence and X-ray induced luminescence in pure and divalent cation doped alkali halides, in the temperature range LNT-RT have been studied. The more important conclusion is that the wavelength spectra in both cases are very similar. This allows a new point of view to be presented on thermoluminescence mechanisms. (author)

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Thermoluminescence dosimetry environmental monitoring system

International Nuclear Information System (INIS)

Bortoluzzi, S.

1989-01-01

In this report, characteristics and performances of an environmental monitoring system with thermoluminescence dosimetry are presented. Most of the work deals with the main physical parameters necessary for measurements of ambiental dose. At the end of this report some of level doses in the environment around the site of the ENEA Center of Energy Research Salluggia (Italy) are illustrated

Thermoluminescent dosimetry of new phosphors of Zn O exposed to beta radiation

International Nuclear Information System (INIS)

Cruz V, C.; Burruel I, S.E.; Grijalva M, H.; Barboza F, M.; Bernal, R.

2004-01-01

In this work, we report the thermoluminescence dosimetry of a new Zn O phosphor obtained by annealing of Zn S powder precipitated when Zn S films were grown by employing a CBD method. The collected Zn S powder was pressed in a die to form pellets which were subjected to different thermal treatments under air atmosphere. X-ray diffraction (XRD) patterns and energy-dispersive X-ray Spectrometry (EDS) analyses confirmed the transformation of Zn S to Zn O. The phosphors thus obtained were exposed to high doses of beta radiation and their thermoluminescent dosimetry show that these new phosphors are materials suitable to be used in high dose thermoluminescence dosimetry. (Author)

Thermoluminescence, luminescence optically stimulated and creation of defects in alkaline halogenides contaminated with Europium

International Nuclear Information System (INIS)

Barboza F, M.

1999-01-01

The alkaline halogenides have been subject matter of investigations related with the search of sensor materials for X-ray bidimensional images or optical memories. The understanding of the damage formation processes generated by ionizing and non-ionizing radiations is important for the correct design of devices that working as detectors and dosemeters of both type of radiations. In this work we present the investigation results related with the defects produced by the ionizing radiation type X and ultraviolet light in the range of 200-360 nm in crystals of KCl: Eu 2+ and KBr:Eu 2+ . It is examined the thermoluminescence and luminescence spectra with the purpose of identifying the exciton processes, owing to the excitation of the halogenide ions in which the primary defects correspond to the F and H centers. It has been found that the 400-600 nm emission is associated with the luminescence type that in his turn can be associated with autotrapped excitons perturbed by the impurity. On the other hand, it is examined the emission spectra of the luminescence optically stimulated in crystals of KBr: Eu 2+ and KCl: Eu 2+ finding too that such materials would be used as optical memories susceptible of to store information, and through of photostimulation to read this. It was determined that the F centers participate in the luminescence optically stimulated in these crystals, as well as too in the recombination processes responsible by the thermoluminescent emission. (Author)

A teoria do “desenvolvimento fragmentador”

Directory of Open Access Journals (Sweden)

Fred Scholz

2010-04-01

Full Text Available O pensamento desenvolvimentista do passado era dominado pela ideia de que o subdesenvolvimento do Terceiro Mundo poderia ser superado mediante ajuda técnica, financeira e pessoal dos países do Norte. A meta era alcançar o nível de desenvolvimento dos países ocidentais industrializados por meio de um desenvolvimento retardatário. Na base dessa ideia estava, por um lado, o consenso de valores ocidental-humanitários, que, o mais tardar desde a época do Esclarecimento, determinou o pensar e o devir social. Por outro lado, a ideia baseou-se na responsabilidade histórica (surgida das condições da Guerra Fria, aceita política e socialmente do "Ocidente" para com os chamados países em desenvolvimento, na sua maioria ex-colônias. Argumenta-se, neste artigo, que a ideia de um desenvolvimento retardatário deve, na era da globalização, ser substituída pelo fato de um desenvolvimento fragmentador.

Thermoluminescence of magnesium doped zirconium oxide (ZrO2:Mg) UV irradiated

International Nuclear Information System (INIS)

Rivera Montalvo, Teodoro; Furetta, Claudio

2008-01-01

Full text: The monitoring of ultraviolet radiation (UVR) different thermoluminescent (TL) materials have been used to measure UVR. UV dosimetry using thermoluminescence phenomena has been suggested in the past by several authors. This technique has an advantage over others methods due to the readout of the samples. Other advantages of these phosphors are their small size, portability, lack of any power requirements, linear response to increasing radiation dose and high sensitivity. Zirconium oxide, recently received full attention in view of their possible use as thermoluminescent dosimeter (TLD), if doped with suitable activators, in radiation dosimetry. In the present investigation thermoluminescent (TL) properties of magnesium doped zirconium oxide (ZrO 2 :Mg) under ultraviolet radiation (UVR) were studied. The ZrO 2 :Mg powder of size 30-40 nm, having mono clinical structure, exhibit a thermoluminescent glow curve with one peak centered at 180 C degrees. The TL response of ZrO 2 :Mg as a function ultraviolet radiation exhibits four maxima centered at 230, 260, 310 and 350 nmn. TL response of ZrO 2 :Mg as a function of spectral irradiance of UV Light was linear in a wide range. Fading and reusability of the phosphor were also studied. The results showed that ZrO 2 :Mg nano powder has the potential to be used as a UV dosemeter in UVR dosimetry. (author)

Desenvolvimento econômico, desigualdade e saúde

Directory of Open Access Journals (Sweden)

Prata Pedro Reginaldo

1994-01-01

Full Text Available O autor se refere a dimensão socioeconômica, individual e coletiva do fenômeno saúde-doença. Refere-se também ao fato das populações estarem sobre a influência desigual de fatores de risco e de proteção à saúde. Discute as desigualdades no desenvolvimento e a relação entre desenvolvimento, riqueza, saúde e justiça social. Questiona as teorias de desenvolvimento econômico, diferenciando desenvolvimento de crescimento. Cunha os conceitos de armadilha do desenvolvimento e refugiados sociais. Define uma comunidade saudável. Propõe a necessidade de mudança no modelo de desenvolvimento. Baliza o papel e as limitações do setor saúde no que diz respeito a iniqüidade social.

Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with 60Co

International Nuclear Information System (INIS)

Ruiz G, B.; Cruz Z, E.; Barboza F, M.

2009-10-01

The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 μm by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with 60 Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

Thermoluminescent dosimetric characterization of the perovskite, KMgF3, activated with lanthanum

International Nuclear Information System (INIS)

Sepulveda M, F.

2003-01-01

The new ICRP regulation about the Radiological Protection allows to the different groups to study new thermoluminescent materials highly sensitive for dosimetric applications (personal and environmental). This work reports the relative experimental results to the thermoluminescent characteristic of a new preparation of the fluorine perovskite activated with lanthanum absorbed in polytetrafluoroethylene (KMgF 3 : LaF 3 + Ptfe). The main thermoluminescent properties investigated were: the TL response like a function of the absorbed dose, the attainable accuracy in the dose measurement, the reproducibility of the TL readings and the threshold dose. The obtained results were compared with the requirements of the ANSI protocol for the environmental dosimetry, resulting in a very good agreement with the required yields. (Author)

Combination of archaeomagnetism and thermoluminescence for precision dating

Science.gov (United States)

Becker, H.; Göksu, H. Y.; Regulla, D. F.

Archaeomagnetic dating was applied to two chalk-burning ovens from an early medieval noble-cemetery. Usually this method allows dating by the investigation of the geomagnetic declination and inclination through the thermoremanent magnetisation of baked clay in situ. However, in this case the method resulted in multiple dates since it was not possible to distinguish the brainching of the geomagnetic secular variation curve. Thermoluminescence dating was applied to the same samples to overcome the problem of multiple dates. This first combined application of archaeomagnetism and thermoluminescence for dating yielded A.D. 670±30 for the two ovens, which dates the first stone-church at the site after a wooden predecessor archeologically dated A.D. 620-630.

Study on carbonated hydroxyapatite as a thermoluminescence dosimeter

International Nuclear Information System (INIS)

Shafaei, M.; Sardari, D.; Ziaie, F.; Larijani, M.M.

2015-01-01

In this study, carbonated hydroxyapatite nanoparticles were used for thermoluminescence dosimetry. The nano-structure carbonated hydroxyapatite synthesized via hydrolysis of CaHPO 4 and CaCO 3 . The obtained nano powders were characterized by XRD technique and FTIR spectroscopy system. The carbonated hydroxyapatite samples were irradiated at different doses using 60 Co gamma rays, and were subjected to thermoluminescence measurement system, consequently. The TL glow curve exhibited two distinguishable peaks centered at around of 165 C and 310 C. The TL response of carbonated hydroxyapatite samples as a function of absorbed dose was linear in the range of 25-1000 Gy. Other dosimetric features of the carbonated hydroxyapatite nanoparticles including fading and reproducibility were also investigated.

The dielectric track and thermoluminescent detectors applied to neutron dosimetry in personnel monitoring

International Nuclear Information System (INIS)

Mebhah, D.

1984-03-01

The personnal dosimeter for neutron based on the detection of fission fragments from 237 Np and 232 Th by a polycarbonate 10 gm, and lithium fluorite 6 LIF/ 7 LIF, allow to cover an energy spectrum from 0.05 eV to 14 MeV with a easy neutron gamma discrimination. In criticality dosimetry, the energy spectrum of the incident neutrons can be defined by two components: the fast component by E b exp(-ae) with E between 0.1 and 14 MeV, a and b determined by a combination of 237 Np and 232 Th track detector responses, and the epithermal component in 1/E, the thermal component having a minor contribution to the total equivalent dose. We took into account the body influence on the detectors response by introducing effective cross section. The equivalent dose obtained by this dosimeter is 20% overestimated in low doses dosimetry. The interpretation of the detectors responses is based on the definition of a factor and a calibration parameter for each zone in which the spectrum is constant. The knowledge of this parameter for individual dosimeters allows to account for the variations of the conditions of calibration

Report on the results of the third intercomparison study of thermoluminescent dosimeters for environmental measurements

International Nuclear Information System (INIS)

Driscoll, C.M.H.

1988-01-01

Scientific laboratories within the Member States of the European Communities have a continuing interest in the use and development of both thermoluminescent dosimeters and thermoluminescence measurement techniques for the assessment of exposure from environmental gamma radiation. In the United Kingdom, for example, environmental thermoluminescent dosimeters have been developed by the National Radiological Protection Board (NRPB) and used in a national survey of indoor radiation exposure. Other laboratories in various Member States are currently involved in similar studies of natural radiation exposure or are using thermoluminescent dosimeters for environmental measurements at reactor sites. Therefore, it is appropriate that such laboratories have facilities within the European Community for standardization and intercomparison of their environmental measurement techniques

Synthetic diamond devices for radiotherapy applications: Thermoluminescent dosimeter and ionisation chamber

International Nuclear Information System (INIS)

Descamps, C.; Tromson, D.; Mer, C.; Nesladek, M.; Bergonzo, P.

2006-01-01

In radiotherapy field, the major usage of dosimeters is in the measurement of the dose received by the patient during radiotherapy (in-vivo measurements) and in beam calibration and uniformity checks. Diamond exhibits several interesting characteristics that make it a good candidate for radiation detection. It is indeed soft-tissue equivalent (Z=6 compared to Z=7.42 for human tissue), mechanically robust and relatively insensitive to radiation damage, chemically stable and non toxic. Moreover, the recent availability of synthetic samples, grown under controlled conditions using the chemical vapour deposition (C.V.D.) technique, allowed decreasing the high cost and the long delivery time of diamond devices. Diamond can be use for off-line dosimetry as thermoluminescent dosimeters or for on-line dosimetry as ionisation chamber [2,3]. These both applications are reported here. For this study, samples were grown in the laboratory and devices were then tested under X-ray irradiations and in clinical environment under medical cobalt source. The work described in this paper was performed in the framework of the European Integrated Project M.A.E.S.T.R.O., Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology, (6. FP) which is granted by the European Commission.The first results of this study clearly show that C.V.D. diamond detectors are suitable for dosimetry in radiotherapy applications. Moreover, for both T.L. dosimeters and ionisation chambers applications, and even though the sensitivity is subsequently reduced, nitrogen incorporation in films seems to significantly improve the dosimetric characteristics of the devices. Therefore, the optimisation of the material quality appears as a very important issue in order to increase the dosimetric characteristics of devices and more particularly, for use as thermoluminescent dosimeters, other impurities (Nickel, Phosphorus) will be tested. For ionisation chamber applications, experiments with

Influence of dopants on the glow curve structure and energy dependence of LiF:Mg,Cu,Si detectors

Energy Technology Data Exchange (ETDEWEB)

Knezevic, Z., E-mail: zknez@irb.h [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Ranogajec-Komor, M.; Miljanic, S. [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Lee, J.I.; Kim, J.L. [Korea Atomic Energy Research Institute, P.O. Box 105 Yuseong, Daejon 305-600 (Korea, Republic of); Music, S. [Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia)

2011-03-15

LiF thermoluminescent material doped with Mg, Cu and Si recently developed by the Korea Atomic Energy Research Institute (KAERI) has shown very good dosimetric properties. Since the thermoluminescence in LiF was found to be dependent on the proper combination of dopants, the investigation of the concentration and type of dopants is very important in developing and characterisation of new TL materials. The aim of this work was to determine the influence of type and concentration of activators on the glow curve structure, sensitivity, reproducibility and on the photon energy response of LiF:Mg,Cu,Si detectors. The energy response was studied in air and on the ISO water phantom in the range of mean photon energies between 33 keV and 164 keV. The morphology and local chemical composition of LiF:Mg,Cu,Si detectors were examined using high resolution scanning electron microscopy (FE-SEM). The results show that type and concentration of activators influence the glow curve and sensitivity. Different dopant concentrations did not show influence on the photon energy response. The sensitivity of LiF:Mg,Cu,Si detector with dopant concentration of Mg = 0.35 mol%, Cu = 0.025 mol% and Si = 0.9 mol% was very high (up to 65 times higher than that of TLD-100). The photon energy response of LiF:Mg,Cu,Si detectors containing all three dopants in various concentrations is in accordance with the IAEA recommendations for individual monitoring.

Influence of dopants on the glow curve structure and energy dependence of LiF:Mg,Cu,Si detectors

International Nuclear Information System (INIS)

Knezevic, Z.; Ranogajec-Komor, M.; Miljanic, S.; Lee, J.I.; Kim, J.L.; Music, S.

2011-01-01

LiF thermoluminescent material doped with Mg, Cu and Si recently developed by the Korea Atomic Energy Research Institute (KAERI) has shown very good dosimetric properties. Since the thermoluminescence in LiF was found to be dependent on the proper combination of dopants, the investigation of the concentration and type of dopants is very important in developing and characterisation of new TL materials. The aim of this work was to determine the influence of type and concentration of activators on the glow curve structure, sensitivity, reproducibility and on the photon energy response of LiF:Mg,Cu,Si detectors. The energy response was studied in air and on the ISO water phantom in the range of mean photon energies between 33 keV and 164 keV. The morphology and local chemical composition of LiF:Mg,Cu,Si detectors were examined using high resolution scanning electron microscopy (FE-SEM). The results show that type and concentration of activators influence the glow curve and sensitivity. Different dopant concentrations did not show influence on the photon energy response. The sensitivity of LiF:Mg,Cu,Si detector with dopant concentration of Mg = 0.35 mol%, Cu = 0.025 mol% and Si = 0.9 mol% was very high (up to 65 times higher than that of TLD-100). The photon energy response of LiF:Mg,Cu,Si detectors containing all three dopants in various concentrations is in accordance with the IAEA recommendations for individual monitoring.

Effect of particle size on the thermoluminescent response of hydroxyapatite

International Nuclear Information System (INIS)

Barrera V, A.; Zarate M, J.; Contreras, M. E.; Rivera M, T.

2016-10-01

We present the study of the structural characterization and the thermoluminescent response of the hydroxyapatite as a function of the calcination temperature and the effect of the particle size. For precipitation synthesis, calcium nitrate (Ca(NO_3)_2 and dibasic ammonium phosphate ((NH_4)_2HPO_4) were used as precursors and ammonium hydroxide (NH_4OH) as a ph controlling agent. The characterization of the samples was carried out by the techniques of X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The powders obtained are composed of hydroxyapatite, with a different degree of dehydroxylation. The thermoluminescent characterization indicates that at higher calcination temperature there is a higher thermoluminescent response, the calcined powders at 1300 degrees Celsius show a very well defined brightness curve with a higher intensity, with its maximum intensity located at a temperature of 210 degrees Celsius, which indicates that this material can be used as a dosimeter. (Author)

Comparing of the yield curve of the pediatric X-ray equipment using thermoluminescent dosimeters and cylindrical ionization chamber

International Nuclear Information System (INIS)

Filipov, Danielle; Schelin, Hugo R.; Tilly Junior, Joao G.

2014-01-01

The determination of the yield curve of a radiographic equipment should be realized once a year, or when the unit be serviced. Besides being a requirement of ANVISA, through this test is possible to determine the incident air kerma (at a given point in the center of the beam) - INAK. Based on these concepts, the main objective of this work is the comparison of yield curves of the pediatric X-ray apparatus using two different detectors: one cylindrical ionization chamber and thermoluminescent dosimeters type LiF: Mg, Cu, P, as per protocol RLA / 9/057 IAEA. Then the equation of the yield curve (generated by each detector) was used to determine the INAK of 10 pediatric examinations, performed on this equipment. After the process of calibration of both detectors, they were placed side by side at a focus of the tube equipment for determining the performance of the same curve. Finally, using the curves generated by two detectors, INAK values of the 10 tests were calculated (from the kVp values, and mAs focus-patient of each exams), generating difference values at most 5%. As a conclusion, it can be said that the TLD lithium fluoride doped with Mg, Cu and P and the cylindrical ionization chambers may be used satisfactorily to determine the yield curve, whether as quality control or dosimetry

Measurements of radon in dwellings with CR-39 track detectors

DEFF Research Database (Denmark)

Majborn, Benny

1986-01-01

A passive integrating dosemeter has been designed for measuring natural radiation in dwellings. The dosemeter contains one or two CR-39 track detectors to measure radon and three thermoluminescence dosemeters to measure external radiation. The dosemeter was investigated in a pilot study in 1983....../84, and it is now used in a nationwide survey of natural radiation in Danish dwellings. The characteristics of the dosemeter with respect to radon measurements are presented, and the radon monitoring results obtained in the pilot study are summarized...

Thermoluminescence properties of irradiated commercial color pencils for accidental retrospective dosimetry

International Nuclear Information System (INIS)

Meriç, Niyazi; Şahiner, Eren; Bariş, Aytaç; Polymeris, George S.

2015-01-01

Color pencils are widely used mostly in kindergartens, in schools and could be found in all houses with families having young children. Their wide spread use in modern times as well as their chemical composition, consisting mostly of Si and Al, constitute two strong motivations towards exploiting their use as accidental retrospective thermoluminescent dosimeters. The present manuscript reports on the study of colored pencils manufactured by a commercial brand in China which is very common throughout Turkey. The preliminary results discussed in the present work illustrated encouraging characteristics, such as the presence of a trapping level giving rise to natural TL in a temperature range that is sufficiently high. Specific thermoluminescence features of this peak, such as glow peak shape and analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability to low attributed doses were studied. The results suggest that the color pencils could be effectively used in the framework of retrospective thermoluminescent dosimetry with extreme caution, based on multiple aliquot protocols. - Highlights: • Thermoluminescence of the inner part of commercial colored pencils was studied. • The presence of a trapping level giving rise to natural TL at 260 °C was yielded. • Deco analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability of this peak were studied

Modulation of the thermoluminescence glow curve of sol-gel synthesized SiO2 and Si O-2:Eu through thermal annealing

International Nuclear Information System (INIS)

Salas J, Ch. J.; Cruz V, C.; Bernal, R.; Castano, V. M.

2015-10-01

Full text: Due to the increasing use of ionizing radiations, is necessary to monitor the radiation fields and exposure doses in facilities in which they are used. Different facilities or applications involve the use of different radiation and doses, and the sort of needed dosimetry also varies. Sometimes a conventional thermoluminescence (Tl) dosimetry satisfy the requirements since the record of the accumulated dose in a time interval is enough, but other cases could require for real-time measurement of a radiation field, being required a non-Tl dosimetric technique. On the other hand, different applications involve the use of different dose ranges, and so dosimeters with different sensitivities are needed. To solve the diverse needs of radiation detectors and dosimeters, a lot of phosphors materials has been characterized concerning their dosimetric capabilities. For medical application, biocompatible materials are desirable. In this work, we present experimental evidence that Sol-Gel synthesized SiO 2 and SiO 2 :Eu phosphors exhibit Tl glow curves composed by the superposition of several individual glow peaks each located at different temperature ranging from values below 100 up to temperatures greater than 400 degrees C, whose relative sensitivities can be modified by subjecting the phosphors to different thermal annealing. By modulating the relative intensities of the individual Tl peaks, glow curves with different shapes are obtained in such a way that SiO 2 and SiO 2 :Eu can be used to develop dosimeters useful for different dose ranges, and for both, conventional thermoluminescence dosimetry and non-thermoluminescence afterglow-based) dosimetry. (Author)

Fast neutron dosimetry using CaSO4:Dy thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorin, N.G.; Salvi, C.R.; Rubio, J.L.; Gutierrez, C.A.

1980-01-01

The use of CaSO 4 :Dy phosphor powder in fast neutron dose measurements using the activation of sulphur from the 32 S(n,p) 32 P reaction is described. The thermoluminescence induced during the irradiation and that due to the decay of short-lived activation products, is erased by annealing the dosimeters after a post-irradiation time of 3 days. The self-induced thermoluminescence measured at different intervals of post-irradiation time, gives an estimation of the fast neutron dose to which the dosimeters were exposed

Thermoluminescence dosimeters with narrow bandpass filters

Science.gov (United States)

Walker, Scottie W.

2004-07-20

A dosimetry method exposes more than one thermoluminescence crystals to radiation without using conventional filters, and reads the energy stored in the crystals by converting the energy to light in a conventional manner, and then filters each crystal output in a different portion of the spectrum generated by the crystals.

Rare earth oxyhalogenide base thermoluminescent material

International Nuclear Information System (INIS)

Rabatin, J.G.

1976-01-01

A process is described that consists to expose a thermoluminescent material to ionizing radiations, the material being a rare earth oxyhalogenide with terbium additions, to heat this material up to the emission of visible radiations and to measure the emitted radiations which are proportional to the ionizing radiation dose [fr

Photoluminescence, trap states and thermoluminescence decay ...

Indian Academy of Sciences (India)

Administrator

Photoluminescence, trap states and thermoluminescence decay process study of Ca2MgSi2O7 : Eu. 2+. , Dy. 3+ phosphor. RAVI SHRIVASTAVA*, JAGJEET KAUR, VIKAS DUBEY and BEENA JAYKUMAR. Govt. VYT PG Autonomous College, Durg 491 001, (C.G.) India. MS received 9 July 2013; revised 5 December 2013.

Thermoluminescent response of aluminium oxide thin films subject to gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Arrieta, A.; Escobar A, L.; Camps, E.; Villagran, E.; Gonzalez, P.R

2006-07-01

The thermoluminescent (TL) properties of amorphous aluminium oxide thin films (thicknesses as low as 0.3 {mu}m) subjected to gamma (Co-60) irradiation are reported. Aluminium oxide thin films were prepared by laser ablation from an Al{sub 2}O{sub 3} target using a Nd: YAG laser with emission at the fundamental line. The films were exposed to gamma radiation (Co-60) in order to study their TL response. Thermoluminescence glow curves exhibited two peaks at 110 and 176 C. The high temperature peak shows good stability and 30% fading in the first 5 days after irradiation. A linear relationship between absorbed dose and the thermoluminescent response for doses span from 150 mGy to 100 Gy was observed. These results suggest that aluminium oxide thin films are suitable for detection and monitoring of gamma radiation. (Author)

Analysis of the thermoluminescent signal in the hydroxyapatite synthesized by the sol-gel method

International Nuclear Information System (INIS)

Mendoza A, D.; Gonzalez, P.R.; Lobato, M.; Rubio, E.; Rodriguez L, V.; Custodio, E.

2004-01-01

The physical properties of the ceramics are related with the chemical bonds and the crystalline structure, because the elements that constitute it can be united by ionic bonds or partially ionic giving a covalent character, this last causes that the outer layer is full of electrons. This property makes that the ceramic ones become interesting materials for thermoluminescent applications, as it demonstrates through the recent works presented on the hydroxyapatite that is a ceramic biomaterials that has shown an interesting thermoluminescent signal when being exposed to gamma radiation. In this sense, this work presents the thermoluminescent signal analysis induced by the UV and gamma radiation in a particular type of hydroxyapatite synthesized by sol gel method in which the temperature synthesis is varied. The final thermoluminescent sensitivity of materials is correlated with the crystalline degree, which is analysed through X-ray diffraction. (Author)

Thermoluminescence studies in geology

International Nuclear Information System (INIS)

Sankaran, A.V.; Sunta, C.M.; Nambi, K.S.V.; Bapat, V.N.

1980-01-01

Even though the phenomenon of thermoluminescence is well studied, particularly over last 3 decades, its potentialities in the field of geology have not been adequately evaluated. In this report several useful applications of TL in mineralogy, petrogenesis, stratigraphy, tectonics, ore-prospecting and other branches have been identified with particular emphasis to the Indian scene. Important areas in the country that may provide the basic material for such studies are indicated at the end along with brief geological or mineralogical accounts. (auth.)

Study of a new glass matrix by the thermoluminescence technique

International Nuclear Information System (INIS)

Ferreira, Pamela Z.; Vedovato, Uly P.; Cunha, Diego M. da; Dantas, Noelio O.; Silva, Anielle C.A.; Neves, Lucio P.; Perini, Ana P.; Carrera, Betzabel N.S.; Watanabe, Shigueo

2015-01-01

The thermoluminescence technique is widely used for both personal and for high-dose dosimetry. In this work, the thermoluminescence technique was utilized to study a new glass matrix, with nominal composition of 20Li 2 CO 3 .10Al 2 O 3 .20BaO.50B 2 O 3 (mol%), irradiated with different doses in a 60 Co source. The glow curves and the dose-response curve were obtained for radiation doses between 50 Gy and 900 Gy. The results showed that this new glass matrix presents potential use in high-dose dosimetry. (author)

Modulation of the thermoluminescence glow curve of sol-gel synthesized SiO{sub 2} and Si O-2:Eu through thermal annealing

Energy Technology Data Exchange (ETDEWEB)

Salas J, Ch. J.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: salasjuarez@gimmunison.com [UNAM, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

2015-10-15

Full text: Due to the increasing use of ionizing radiations, is necessary to monitor the radiation fields and exposure doses in facilities in which they are used. Different facilities or applications involve the use of different radiation and doses, and the sort of needed dosimetry also varies. Sometimes a conventional thermoluminescence (Tl) dosimetry satisfy the requirements since the record of the accumulated dose in a time interval is enough, but other cases could require for real-time measurement of a radiation field, being required a non-Tl dosimetric technique. On the other hand, different applications involve the use of different dose ranges, and so dosimeters with different sensitivities are needed. To solve the diverse needs of radiation detectors and dosimeters, a lot of phosphors materials has been characterized concerning their dosimetric capabilities. For medical application, biocompatible materials are desirable. In this work, we present experimental evidence that Sol-Gel synthesized SiO{sub 2} and SiO{sub 2}:Eu phosphors exhibit Tl glow curves composed by the superposition of several individual glow peaks each located at different temperature ranging from values below 100 up to temperatures greater than 400 degrees C, whose relative sensitivities can be modified by subjecting the phosphors to different thermal annealing. By modulating the relative intensities of the individual Tl peaks, glow curves with different shapes are obtained in such a way that SiO{sub 2} and SiO{sub 2}:Eu can be used to develop dosimeters useful for different dose ranges, and for both, conventional thermoluminescence dosimetry and non-thermoluminescence afterglow-based) dosimetry. (Author)

Historical note: thermoluminescent dosimetry (LiF) 1950-51

International Nuclear Information System (INIS)

Heckelsberg, L.F.

1980-01-01

The early history of thermoluminescent dosimetry has not been adequately described and one of the first workers in this field takes this opportunity to record more fully the history of the period. (author)

Design and development of low cost thermoluminescence measurement system using PIC16F877 microcontroller

International Nuclear Information System (INIS)

Neelamegam, P; Rajendran, A

2006-01-01

A real time microcontroller based thermoluminescence system has been developed to measure light intensity and temperature and to control linear heating. This instruments permits to conduct investigations on thermoluminescent materials, such as alkali halides, phosphors and related compounds, which have important applications in materials science and in dosimetry. A low cost dedicated PIC16F877 based microcontroller board was employed for the hardware. The detail of its interface and software to measure thermoluminescence and to send data to PC is explained in this paper

Design and development of low cost thermoluminescence measurement system using PIC16F877 microcontroller

Energy Technology Data Exchange (ETDEWEB)

Neelamegam, P [Department of Electronics and Instrumentation Engineering, Shunmuga Arts, Science, Technology and Research Academy (SASTRA), Deemed University, Thanjavur-613 402, Tamil Nadu (India); Rajendran, A [PG and Research Department of Applied Physics, Nehru Memorial College (Autonomous), Puthanampatti-621 007, Tiruchirappalli, Tamil Nadu (India)

2006-05-15

A real time microcontroller based thermoluminescence system has been developed to measure light intensity and temperature and to control linear heating. This instruments permits to conduct investigations on thermoluminescent materials, such as alkali halides, phosphors and related compounds, which have important applications in materials science and in dosimetry. A low cost dedicated PIC16F877 based microcontroller board was employed for the hardware. The detail of its interface and software to measure thermoluminescence and to send data to PC is explained in this paper.

Thermoluminescence in some copper-doped compounds

International Nuclear Information System (INIS)

Patil, R.R.; Moharil, S.V.; Dhopte, S.M.; Muthal, P.L.; Kondawar, V.K.

2003-01-01

Thermoluminescence (TL) in various Cu + -doped materials is studied. A good correlation between the presence of copper in the Cu + form and TL sensitivity is observed. Correlation between TL emission spectra and photoluminescence suggests that Cu + acts as the emission center in the TL process. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Design and validation of a single sphere multi-detector neutron spectrometer based on LiF: Mg,Cu,P thermoluminescent dosemeters

International Nuclear Information System (INIS)

Gomez-Ros, Jose Maria; Bedogni, Roberto; Moraleda, Montserrat; Romero, Ana; Delgado, Antonio; Esposito, Adolfo

2010-01-01

This communication describes a new neutron spectrometer consisting of pairs of 7 Li and 6 Li based thermoluminescent dosemeters (MCP-6, MCP-7) located at selected positions within a single moderating polyethylene sphere. The spatial arrangement of the dosemeters has been designed using the MCNPX Monte Carlo code to calculate the response matrix in order to obtain a nearly isotropic response for neutrons in the energy range up to 20 MeV. A partial validation of the calculated response matrix has been performed with the calibrated 241 Am-Be neutron source at the INFN-LNF Laboratory, using the shadow cone technique.

Irradiated black pepper identification based on thermoluminescence of silicate minerals

International Nuclear Information System (INIS)

Faycal Kharfi; Randa Ketfi

2018-01-01

In this work we have successfully implemented thermoluminescence TL method for irradiated food identification. First tests are performed on Indian black pepper and show promising results to extend the proposed method to many other foods. The X-ray diffraction (XRD) shows that SiO 2 (p3 2 21) is the main component of the separated mineral phase. A saturation dose of ∼ 100 Gy is determined for this pepper above which all thermoluminescent centers of the quartz are activated. Thus, above this threshold dose, only the pepper irradiation will be confirmed but no accuracy on the exact dose received. (author)

State of the art in thermoluminescent dosimetry using dosemeters with automated read-out

International Nuclear Information System (INIS)

Regulla, D.F.

1979-01-01

In the beginning, the results obtained with automated read-out TLD have been quite disappointing, both for manufacturers and users. In response to this, industry then seeked advice and assistance from those experienced in the practical use of dosemeters, and the development of the second generation of automated TLD has been a common task of manufacturers and purchosers. As a preliminary achievement of development work along this line, a dosemeter has been presented by a Japanese manufacturer, meeting the requirements in quite a satisfactory way. The device is characterized by a frequency of disturbance of -5 , a microprocessor for controlling the measuring and control functions, possibility of active input of device parameters and boundary conditions, extensive self-control of operating functions, complete data protection, and thin-film detector technique. Pursuing this line of development, and taking into account future recommentations, automated thermoluminescent dosimetry does seem to be a promising alternative to current measuring techniques in personnel monitoring. (orig./RW) [de

O DIREITO FUNDAMENTAL AO DESENVOLVIMENTO SUSTENTÁVEL

OpenAIRE

Fernandes, Jeferson Nogueira

2012-01-01

Este artigo jurídico trata do direito fundamental do ser humano ter um desenvolvimento sustentável, e tem como objetivo identificar o desenvolvimento sustentável como sendo um direito fundamental consagrado universalmente. Em sua elaboração foi utilizado o seguinte material: textos doutrinários, legislação nacional pertinente e documentos internacionais. A conclusão indica que: o desenvolvimento sustentável é um direito fundamental do homem e que devemos manter equilibrada a relação ambiente ...

Saúde e desenvolvimento

Directory of Open Access Journals (Sweden)

Ana Luiza D'Ávila Viana

Full Text Available Considerando que os modernos sistemas de saúde são o resultado da complexa interação de processos econômicos, políticos e sociais, o objetivo do trabalho é discutir a relação entre saúde e desenvolvimento no Brasil, mostrando que o esgotamento do modelo liberal de política econômica abre nova perspectiva para a retomada do desenvolvimento, entendido como combinação entre crescimento da economia, mudanças na estrutura produtiva e melhora das condições de vida da população. O complexo produtivo da saúde joga papel decisivo nesse processo, pois constitui um campo em que inovação tecnológica e acumulação de capital geram oportunidades de investimento, trabalho e renda, além de produzir avanços importantes para melhorar o estado de saúde das pessoas. A recente adoção de políticas públicas voltadas para articular, de forma positiva, aspectos da política econômica e da política social revela que a questão do desenvolvimento nacional ganhou nova centralidade na agenda governamental, o que abre a perspectiva de maior integração entre a lógica econômica e a lógica sanitária. Entretanto, é preciso reconhecer que o Brasil ainda não logrou alcançar uma associação virtuosa entre saúde e desenvolvimento.

Preparation and structural characterization of the thermoluminescent material CaSO4: Dy

International Nuclear Information System (INIS)

Sanchez R, A.; Azorin, J.; Gonzalez M, P.R.; Rivera, T.

2005-01-01

The grade of crystallinity of a material is important so that the one is presented the thermoluminescence phenomenon; for what is necessary to study those structural characteristic of a TL material and to correlate them with its TL response when being irradiated with ionizing radiation. The calcium sulfate activated with Dysprosium (CaSO 4 : Dy) it is a material that has demonstrated its efficiency in the dosimetry of the ionizing radiation for the thermoluminescence method. In this work the structural characterization of this prepared material for the recrystallization method by means of the evaporation of the solvent and their relationship with their TL response is presented. The results showed that the best material to be used in thermoluminescent dosimetry presents a crystalline structure in orthorhombic phase and a particle size in the interval of 80 μm to 200 μm. (Author)

Numerical analysis of thermoluminescence glow curves; Analisis numerico de las cruvas de termoluminiscencia

Energy Technology Data Exchange (ETDEWEB)

Gomez Ros, J M; Delgado, A

1989-07-01

This report presents a method for the numerical analysis of complex thermoluminescence glow curves resolving the individual glow peak components. The method employs first order kinetics analytical expressions and is based In a Marquart-Levenberg minimization procedure. A simplified version of this method for thermoluminescence dosimetry (TLD) is also described and specifically developed to operate whit Lithium Fluoride TLD-100. (Author). 36 refs.

Thermoluminescent Dosimeter as the Gamma Component of a Nuclear Accident Dosimeter; Utilisation du Dosimetre Thermoluminescent Comme Element Detecteur Gamma d'un Dosimetre pour les cas d'Accident Nucleaire; 0422 0415 0420 041c 0414 ; Los Detectores de Termoluminiscencia Como Elemento Gammametrico de un Dosimetro para Casos de Accidente Nuclear

Energy Technology Data Exchange (ETDEWEB)

Handloser, J. S. [Edgerton, Germeshausen and Grier, Inc., Santa Barbara, CA (United States)

1965-06-15

Various types of gamma dosimeters have been employed as the gamma-measuring component of accident dosimeters. These have included various types of glass dosimeters, film, chemical dosimeters and polymerization dosimeters. The thermoluminescent dosimeter has notable advantages over these other types. The wide range of the thermoluminescent dosimeter permits it to be used both as a daily monitor for radiation protection purposes and as an accident dosimeter. This concept eliminates the need for special instrumentation for accident dosimeters and allows the well-calibrated instrumentation in daily use to be utilized in the accident dosimeter system. Commonly, the thermoluminescent dosimeter's inherent range is from 5 mr to 100 000 r, with a reproducibility of {+-} 10%. A single-type calcium fluoride dosimeter and associated readout equipment has been designed and manufactured to cover 5 mr to 5000 r. Readout of the dosimeter is accomplished by heating the phosphor and measuring the light output. Six decade readout instruments are available and completely automated systems have been designed. None of the readout equipment requires more than 20 seconds per dosimeter. Another advantage of the thermoluminescent dosimeter is the low neutron response. The neutron response will vary with the type of container and the type of phosphor. One type of calcium fluoride dosimeter has a neutron response of 0.27 x 10{sup -9} rad per n/cm{sup 2}. Two physical forms of the thermoluminescent dosimeter are considered. The first is an internally heated evacuated dosimeter contained in a glass envelope. This dosimeter is about 3/8-in diam.x 2 Vulgar-Fraction-One-Half -in long. The second type consists of a small-bore glass tube with the phosphor sealed inside. This dosimeter is 0.8-mm diam. x 6-mm long. Energy response correction shields have been designed for both types of dosimeter. (author) [French] L'auteur a employe divers types de cellules comme elements detecteurs des rayons gamma

Measurement conditions of natural soil thermoluminescence and their application in a granite type uranium deposit

International Nuclear Information System (INIS)

Chen Yue; Yang Yaxin; Liu Qingcheng

2009-01-01

A measuring method of natural soil thermoluminescence is used for prospecting of uranium deposits. The better effects are obtained by using the method, but the parameters selected have significant effects on the intensity of soil thermoluminescent. So, the measuring parameters are selected according to the different soil samples. Based on the measuring 1 000 soil samples of granite type uranium deposit,the optimum heating up program of natural soil thermoluminescence is obtained, that is, preheating, lasting heating, constant temperature and the halting heating. The parameters selected are as follows: the heating rate being 15 degree C/s, the temperatures of the first and second constant temperature being 135 degree C and 400 degree C respectively. Using the selected parameters for measuring soil samples from a known mining area in Guangdong province, the result indicates that the abnormities of thermoluminescence have corresponding relations with the underground orebodies. (authors)

Needle-type differential thermoluminescent dosemeter

International Nuclear Information System (INIS)

Kubu, M.

1988-01-01

The dosemeter serves to measure the depth distribution of absorbed dose in a phantom in mixed neutron and gamma radiation fields. It consists of a stratified cylindrical absorber in which alternate moderator and cadmium layers. Inside are two bores along the longitudinal axis for tubes filled with 6 LiF and 7 LiF powder thermoluminescent dosemeters. The device is easily portable and allows to carry out measurements with a high level of reproducibility. (J.B.). 4 figs

Thermoluminescence in CVD diamond films: application to actinometric dosimetry

International Nuclear Information System (INIS)

Barboza-Flores, M.; Melendrez, R.; Chernov, V.; Castaneda, B.; Pedroza-Montero, M.; Gan, B.; Ahn, J.; Zhang, Q.; Yoon, S.F.

2002-01-01

Diamond is considered a tissue-equivalent material since its atomic number (Z=6) is close to the effective atomic number of biological tissue (Z=7.42). Such a situation makes it suitable for radiation detection purposes in medical applications. In the present work the analysis is reported of the thermoluminescence (TL) and dosimetric features of chemically vapour deposited (CVD) diamond film samples subjected to ultraviolet (UV) irradiation in the actinometric region. The TL glow curve shows peaks at 120, 220, 320 and 370 deg. C. The 120 and 370 deg. C peaks are too weak and the first one fades away in a few seconds after exposure. The overall room temperature fading shows a 50% TL decay 30 min after exposure. The 320 deg. C glow peak is considered to be the most adequate for dosimetric applications due to its low fading and linear TL behaviour as a function of UV dose in the 180-260 nm range. The TL excitation spectrum presents a broad band with at least two overlapped components around 205 and 220 nm. The results indicate that the TL behaviour of CVD diamond film can be a good alternative to the currently available dosemeter and detector in the actinometric region as well as in clinical and medical applications. (author)

Thermoluminescence properties of alkali borate glasses containing neodymium

Energy Technology Data Exchange (ETDEWEB)

Abbas, A.F.; Henaish, B.A.; Kenaway, M.A.; Salem, L.R.

1988-01-01

The thermoluminescence properties of sodium borate glasses as a function of neodymium oxide content as well as the divalent metal oxides (RO = ZnO, MgO and CaO) in replacement of Na/sub 2/O have been investigated. It is observed that the addition of Nd/sub 2/O/sub 3/ imparts to the host glass a monopeak glow curve according to an active luminescent centre (E approx. = 0.97 eV to 1.232 eV). The gradual addition of neodymium oxide to the sodium borate glass causes gradual enhancement in the TL-intensity up to a quenching concentration value (4 g Nd/sub 2/O/sub 3/ added to 100 g of borate glass) above which a draw back in TL-intensity occurs. On the other hand the replacement of 5 wt% Na/sub 2/O by RO shows that CaO dominates the other two divalent metal oxides used, as it possesses a much deeper luminescent trap (1.232 eV). The results obtained suggest that these glasses can be used in radiation detection and dosimetry. The ..gamma..-induced Tl-signal of such type of glass is found to be reproducible within an acceptable error of not more than 3.5% in all individual and group scattering over the detector samples each of which is used 10 times for evaluating the same ..gamma..-dose.

An intercomparison of the thermoluminescent efficiency of various preparations of lithium fluoride

CERN Document Server

Driscoll, C M H

1977-01-01

Possible alternative sources of supply of lithium fluoride to that used at present in the NRPB automated TLD system dosemeter are being considered on the grounds of economy and quality control. Initial measurements on the thermoluminescent properties and efficiency of various preparations of lithium fluoride are described, including the Harshaw TLD-700 which is currently in use in the automated thermoluminescent dosemeter. Material obtained from British Nuclear Fuels Ltd (which may be an atypical batch) showed 75% of the sensitivity of the Harshaw material, with around 20% fading of the signal after 1 month's storage. French material, obtained from Desmarquest and Carbonisation Entreprise et Ceramique and used by the Commissariat a l'Energie Atomique, showed good fading resistance but, after standard preparational treatments, was only half as sensitive in the thermoluminescent response. Without additional treatments to improve the characteristics of these materials, they cannot be considered as being satisfac...

Statistical methods to evaluate thermoluminescence ionizing radiation dosimetry data

International Nuclear Information System (INIS)

Segre, Nadia; Matoso, Erika; Fagundes, Rosane Correa

2011-01-01

Ionizing radiation levels, evaluated through the exposure of CaF 2 :Dy thermoluminescence dosimeters (TLD- 200), have been monitored at Centro Experimental Aramar (CEA), located at Ipero in Sao Paulo state, Brazil, since 1991 resulting in a large amount of measurements until 2009 (more than 2,000). The data amount associated with measurements dispersion, since every process has deviation, reinforces the utilization of statistical tools to evaluate the results, procedure also imposed by the Brazilian Standard CNEN-NN-3.01/PR- 3.01-008 which regulates the radiometric environmental monitoring. Thermoluminescence ionizing radiation dosimetry data are statistically compared in order to evaluate potential CEA's activities environmental impact. The statistical tools discussed in this work are box plots, control charts and analysis of variance. (author)

Thermoluminescent response of LaAlO{sub 3}:Pr; Respuesta termoluminiscente de LaAlO{sub 3}:Pr

Energy Technology Data Exchange (ETDEWEB)

Morales H, A.; Zarate M, J. [Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Investigacion en Metalurgia y Materiales, Ciudad Universitaria, Edif. U, 58060 Morelia, Michoacan (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Rivera M, T., E-mail: feyo_yo@hotmail.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico)

2015-10-15

In this study, the thermoluminescence response of doped lanthanum aluminate (LaAlO{sub 3}) with praseodymium ion (Pr) obtained by the Pechini method and drying by the spraying technique Spry Dryer was studied. The obtained powders were analyzed structurally by the X-ray diffraction technique; the morphological characterization was by the scanning electron microscopy technique. The obtained powders at 800 degrees C presented crystallinity and showed a Rhombohedral crystal structure, this phase was observed by X-ray diffraction patterns. Thermoluminescence response of LaAlO{sub 3}:Pr showed a brightness curve with a peak centered at 157 degrees C. The sensitivity of the doped samples was improved about 90 times in comparison with the undoped sample. Thermoluminescence response in function of the wavelength showed a maximum at 230 nm, reproducibility of thermoluminescence response was ±50%. Also the fading in thermoluminescence response was studied. (Author)

DIREITOS HUMANOS, DESENVOLVIMENTO SUSTENTÁVEL E SUSTENTABILIDADE

OpenAIRE

Carvalho, Sonia Aparecida de; Silva, Denival Francisco da; Adolfo, Luiz Gonzaga Silva

2015-01-01

Este artigo trata da relação intrínseca entre os direitos humanos, o desenvolvimento sustentável e a sustentabilidade. Seu objetivo geral consiste em analisar o modelo de desenvolvimento implementado e a necessária proteção e preservação do meio ambiente ligado à defesa dos direitos humanos. Os objetivos específicos pretendem investigar a distinção dos termos sustentabilidade e desenvolvimento sustentável, como a concretização do direito à sustentabilidade, os critérios e as dimensões da sust...

Method of preparing a thermoluminescent phosphor

Science.gov (United States)

Lasky, Jerome B.; Moran, Paul R.

1979-01-01

A thermoluminescent phosphor comprising LiF doped with boron and magnesium is produced by diffusion of boron into a conventional LiF phosphor doped with magnesium. Where the boron dopant is made to penetrate only the outer layer of the phosphor, it can be used to detect shallowly penetrating radiation such as tritium beta ays in the presence of a background of more penetrating radiation.

Gestões do desenvolvimento e desenvolvimentos da gestão: da unilateralidade reificada à dialogicidade da simbiose homem/natureza

Directory of Open Access Journals (Sweden)

Carlos Eduardo Justen

Full Text Available Este artigo, ao situar culturalmente os fenômenos da gestão e do desenvolvimento, em sua concepção tradicional, no projeto da modernidade e ao identificar o predomínio da unilateralidade reificada na interface entre gestão e desenvolvimento - a primeira vista como instrumento técnico submisso à via clássica do segundo - almeja evidenciar as potencialidades da compreensão e da construção de alternativas, tanto para a gestão como para o desenvolvimento, a partir da ressignificação dessa interface. Para tanto, o esforço foi direcionado ao resgate do que é comum aos fenômenos da gestão e do desenvolvimento - os substratos antropológico e ecológico -, nucleados nos princípios da reciprocidade dialógica, concretizadora da condição antropológica, e da finitude, caracterizadora da condição ecológica. Ao final, são apresentadas oito potenciais contribuições advindas da exploração renovada da interface entre a gestão e o desenvolvimento. Propôs-se, ainda, a substituição da lógica instrumental da eficiência financeira, comum à concepção tradicional dos fenômenos estudados, pela lógica da simbiose dialógica homem/natureza, uma vez que, como fenômenos sociais, desenvolvimento e gestão, mediados pelo meio, também são ecológicos em sua essência.

Study of natural thermoluminescence of quartzite in a gold and uranium mineralized zone (Canavieiras, Jacobina, Brazil)

International Nuclear Information System (INIS)

Ferreira, J.; Nordemann, D.

1976-01-01

The quartzite of the Canavieiras gold mine (Jacobina, Bahia, Brazil) exhibits a high temperature peak (280 +- 2) 0 C in its natural thermoluminescence glow curve. It was experimentally determined that the amount of light in this peak could be reproduced to within 5% for grain sizes between 80 and 100 mesh (0.149 and 0.177 mm). A positive correlation was found between the amount of this thermoluminescence and the uranium content with saturation beginning to be detected at the maximum (700 ppm) amount of uranium found. Assuming that the thermoluminescence peak used is at a temperature high enough to permit accumulation and stability at room temperatures, the thermoluminescence found could have accumulated in (12.1 +- 0.3) x 10 6 years. This may date a complete liberation of trapped electrons in conjunction with a well documented initiation of weathering. (author) [pt

The thermoluminescence glow-curve analysis using GlowFit - the new powerful tool for deconvolution

International Nuclear Information System (INIS)

Puchalska, M.; Bilski, P.

2005-10-01

A new computer program, GlowFit, for deconvoluting first-order kinetics thermoluminescence (TL) glow-curves has been developed. A non-linear function describing a single glow-peak is fitted to experimental points using the least squares Levenberg-Marquardt method. The main advantage of GlowFit is in its ability to resolve complex TL glow-curves consisting of strongly overlapping peaks, such as those observed in heavily doped LiF:Mg,Ti (MTT) detectors. This resolution is achieved mainly by setting constraints or by fixing selected parameters. The initial values of the fitted parameters are placed in the so-called pattern files. GlowFit is a Microsoft Windows-operated user-friendly program. Its graphic interface enables easy intuitive manipulation of glow-peaks, at the initial stage (parameter initialization) and at the final stage (manual adjustment) of fitting peak parameters to the glow-curves. The program is freely downloadable from the web site www.ifj.edu.pl/NPP/deconvolution.htm (author)

Thermoluminescence of sulfated zircon exposed to gamma radiation

International Nuclear Information System (INIS)

Rubio, E.; Castano, V.M.; Mendoza A, E.; Gonzalez, P.R.

2003-01-01

In this work, the thermoluminescent (Tl) signal induced by gamma radiation in zirconia and sulfated zirconia samples embedded in Ptfe pellets is reported and discussed. In this case, samples were obtained through sol-gel method using zirconium n-propoxide and H 2 SO 4 as precursors, and later were subjected to thermal treatment at 600 C to obtain, the tetragonal phase accordingly to X-ray diffraction analysis. Experimental results show that the thermoluminescent glow peak depends on both, the crystalline structure and sulfate concentration. Two maximum peaks were observed located at 147 C and 274 C arising from the electronic transitions. Tl response as a function of the absorbed dose shows a linear increase for a wide of range exposure as well as good stability in time. The high sensitivity, dose linearity and signal stability of this material open the potential possibility to be used for the dosimetry applications. (Author)

Thermoluminescence method for detection of irradiated food

International Nuclear Information System (INIS)

Pinnioja, S.

1998-01-01

A method of thermoluminescence (TL) analysis was developed for the detection of irradiated foods. The TL method is based on the determination of thermoluminescence of adhering or contaminating minerals separated from foods by wet sieving and treatment with high density liquid. Carbon tetrachloride provided a suitable alternative for foods that form gels with water. Thermoluminescence response of minerals in a first TL measurement is normalised with a second TL measurement of the same mineral sample after calibration irradiation to a dose of 5 kGy. The decision about irradiation is made on the basis of a comparison of the two TL spectra: if the two TL glow curves match in shape and intensity the sample has been irradiated, and if they are clearly different it has not been irradiated. An attractive feature of TL analysis is that the mineral material itself is used for calibration; no reference material is required. Foods of interest in the investigation were herbs, spices, berries and seafood. The presence of minerals in samples is a criterion for application of the method, and appropriate minerals were found in all herbs, spices and berries. The most common minerals in terrestrial food were tecto-silicates - quartz and feldspars - which with their intense and stable thermoluminescence were well suited for the analysis. Mica proved to be useless for detection purposes, whereas carbonate in the form of calcite separated from intestines of seafood was acceptable. Fading of the TL signal is considerable in the low temperature part of the glow curve during a storage of several months after irradiation. However, spices and herbs could easily be identified as irradiated even after two years storage. Conditions for seafood, which is stored in a freezer, are different, and only slight fading was observed after one year. The effect of mineral composition and structure on TL was studied for feldspars. Feldspars originating from subtropical and tropical regions exhibit lower TL

Thermoluminescence method for detection of irradiated food

Energy Technology Data Exchange (ETDEWEB)

Pinnioja, S

1998-12-31

A method of thermoluminescence (TL) analysis was developed for the detection of irradiated foods. The TL method is based on the determination of thermoluminescence of adhering or contaminating minerals separated from foods by wet sieving and treatment with high density liquid. Carbon tetrachloride provided a suitable alternative for foods that form gels with water. Thermoluminescence response of minerals in a first TL measurement is normalised with a second TL measurement of the same mineral sample after calibration irradiation to a dose of 5 kGy. The decision about irradiation is made on the basis of a comparison of the two TL spectra: if the two TL glow curves match in shape and intensity the sample has been irradiated, and if they are clearly different it has not been irradiated. An attractive feature of TL analysis is that the mineral material itself is used for calibration; no reference material is required. Foods of interest in the investigation were herbs, spices, berries and seafood. The presence of minerals in samples is a criterion for application of the method, and appropriate minerals were found in all herbs, spices and berries. The most common minerals in terrestrial food were tecto-silicates - quartz and feldspars - which with their intense and stable thermoluminescence were well suited for the analysis. Mica proved to be useless for detection purposes, whereas carbonate in the form of calcite separated from intestines of seafood was acceptable. Fading of the TL signal is considerable in the low temperature part of the glow curve during a storage of several months after irradiation. However, spices and herbs could easily be identified as irradiated even after two years storage. Conditions for seafood, which is stored in a freezer, are different, and only slight fading was observed after one year. The effect of mineral composition and structure on TL was studied for feldspars. Feldspars originating from subtropical and tropical regions exhibit lower TL

Thermoluminescence sensitivity of ulexite after UV irradiation

Energy Technology Data Exchange (ETDEWEB)

Topaksu, M., E-mail: mats@cu.edu.tr [Cukurova University, Arts-Sciences Faculty, Physics Department, 01330 Adana (Turkey); CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Correcher, V. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Garcia-Guinea, J. [Museo Nacional de Ciencias Naturales, (CSIC), C/José Gutiérrez Abascal 2, 28006 Madrid (Spain)

2015-04-15

Highlights: •UV-induced thermoluminescence emission of Turkish ulexite was studied. •There are three groups of components. •The UV exposures were performed at controlled temperatures. -- Abstract: The effects of UV radiation on the thermoluminescence (TL) properties of natural materials, in contrast to synthetic materials, have been scarcely studied. We report on the UV-induced thermoluminescence emission of a Turkish ulexite (NaCaB{sub 5}O{sub 6}(OH){sub 6}·5H{sub 2}O) that displays very complex TL glow curves, with at least three groups of components peaked at 130–140 °C, 240 °C and, 340 °C, wherein the last group is weaker. Such emission could be associated with structural changes in the lattice as well as alkali self-diffusion processes. The UV exposure performed at controlled temperatures (at room temperature (RT), 50 °C and 100 °C) produced a (i) different evolutions of the intensities of each maximum, which are directly related to the controlled thermal treatment; (ii) different intensity ratios among the groups of components; (iii) different activation energies (E{sub a}) (1.13 eV for RT, 0.99 eV for 50 °C and 0.49 eV for 100 °C) calculated using the initial rise method; and (iv) similar scattering values (12.4%, 8.2% and 12.8%), which were not a function of the controlled temperature. The thermal stability tests conducted on this borate at different temperatures, based on the T{sub stop} protocol, confirm the presence of a continuum in the distribution of the trap system with progressively increasing E{sub a} (from 0.60 to 0.90 eV)

Thermoluminescence characterization of LiMgF3: DyF3 phosphors exposed to beta radiation

International Nuclear Information System (INIS)

Bernal, R.; Alday S, K.R.; Brown, F.; Cruz V, C.; Furetta, C.; Cruz Z, E.; Kitis, G.

2006-01-01

LiMgF 3 : DyF 3 phosphors were obtained as polycrystalline solids from the melting of component salts, with two DyF 3 concentrations, 2.02 % mol, and 4.04 % mol. In order to guarantee the homogeneity of composition, the samples were crushed and the resulting powder was pressed to form pellet-shaped phosphors, some of which were sintered at 700 C for 5 h under air atmosphere. Thermoluminescence measurements of beta irradiated samples show that these phosphors exhibit adequate properties to be considered for development of thermoluminescence dosimeters. Integrated thermoluminescence as a function of dose displays a linear dependence with dose for doses below 20.0 Gy. (Author)

Thermoluminescence, a method for determining the date at which a ceramic object was fired

International Nuclear Information System (INIS)

Sayre, E.V.

The theory on which thermoluminescence dating of archeological ceramic objects is based and the measurement methods used are outlined. Separation of fine grain particles and quartz particles permits the determination of the thermoluminescence of each and often a more accurate age determination. The application of the method to the dating of a bronze horse from the Metropolitan Museum is described

Thermoluminescence authentication of T'ang and Han Dynasty pottery

International Nuclear Information System (INIS)

Price, D.M.

1997-01-01

More than 80 pieces of T'ang Dynasty and 40 Han Dynasty style ceramic wares have been analysed to determine the amount of thermoluminescence (TL) accumulated since the initial firing of the object and the level of the radiation flux which has created the TL. This paper presents a summary of the thermoluminescence analysis results. Approximately 60% of Han ceramics and 45% of the T'ang pottery authenticated have been shown to belong to periods other than that stylistically suggested. Items which have been found not to be of the anticipated antiquity generally fall into distinct age groups. Of the T'ang wares the most commonly copied item is found to be the horse and for the Han pieces, human figures and ewers/pots/vases represent the most frequently reproduced wares

Thermoluminescence dating. Application to the chronology of volcanic ashes

International Nuclear Information System (INIS)

Pilleyre, T.

1991-09-01

Thermoluminescent (TL) dating is generally used for minerals heated in the past and can be used for absolute chronology of volcanic ashes but seems limited to less than 15.000 years. The aim of the thesis is the study of thermoluminescent properties of quartz for high doses and long irradiations using the red TL peak of quartz which is situated at high temperature (about 370 deg. C) to extend the method for higher ages. A theory, based on spatial correlation between electron and hole created during the same ionization, is developed. A chapter is devoted to dosimetry because of its importance in TL dating, especially alpha scintillation counting and the influence of humidity on the determination of annual dose. Volcanic samples are dated from 10.000 to 80.000 years before present

The thermoluminescence of carp otoliths: A fingerprint in ...

African Journals Online (AJOL)

use

2011-12-14

Dec 14, 2011 ... provide a quick and qualitative means for environmental assessments in lake pollution. Key words: Thermoluminescence, fish otolith, heavy-metal elements, lake, pollution. INTRODUCTION. Fish otoliths are widely .... cleaned HDPE plastic bottles that have been rinsed with sample three times prior to use.

The Properties of CaSO{sub 4}: Mn Thermoluminescence Dosimeters

Energy Technology Data Exchange (ETDEWEB)

Bjaerngard, Bengt

1963-06-15

The properties of the radio thermoluminescence of CaSO{sub 4}:Mn, used for dosimetry of gamma and roentgen radiation, have been investigated. The light yield of the luminophore has been determined to 1.5 percent for 1 MeV gamma radiation. The dependence of the thermoluminescence light sum on the exposure, the exposure rate, and the exposure time can qualitatively be described by the first order process model, modified by a broad energy distribution of the electron trap depths. Some applications are discussed. The cheapness of the dosimeters, the convenient read-out, and the broad range of measurable exposures suggest that CaSO{sub 4}:Mn can be a valuable complement to other dosimetry systems.

Synthesis and thermoluminescence of LaAlO3:Pr3+ to UVC radiation dosimetry

International Nuclear Information System (INIS)

Morales-Hernández, A.; Zarate-Medina, J.; Contreras-García, M.E.; Azorín-Nieto, J.; Rivera-Montalvo, T.

2016-01-01

Thermoluminescent (TL) response of trivalent praseodymium ion doped lanthanum aluminate (LaAlO 3 :Pr 3+ ) obtained by Pechini method and Spray Dryer was studied. TL response of LaAlO 3 :Pr 3+ powders submitted at 1600 °C exhibited one peak centered at 157 °C. Sensitivity of LaAlO 3 :Pr 3+ was improved in around 90 times compared with undoped LaAlO 3 . TL response as a function of wavelength showed a maximum in 230 nm. Dosimetric characteristics of LaAlO 3 :Pr 3+ under UVR radiation effects were analyzed. Evaluation of activation energy was obtained by Glow Fit v.1.3 software. Experimental results about thermoluminescent characteristics of LaAlO 3 :Pr 3+ suggest as good candidate to be employed as a complementary thermoluminescent device with other TL phosphors as aluminum oxide - Highlights: • High sensitivity of new phosphor to UVC dosimetry was is studied. • Thermoluminescence response of LaAlO 3 :Pr 3+ is presented. • LaAlO 3 :Pr 3+ is suggested as UVCR dosimeter. • TL response of LaAlO 3 :Pr 3+ has dependence on sintering temperature.

Thermoluminescent characteristics of CaSO4:Dy+PTFE irradiated with high energy electron beams

International Nuclear Information System (INIS)

Alvarez, R.; Rivera, T.; Calderon, J. A.; Jimenez, Y.; Rodriguez, J.; Oviedo, O.; Azorin, J.

2011-10-01

In the present work thermoluminescent response of dysprosium doped calcium sulfate embedded in polytetrafluorethylene (CaSO 4 :Dy+PTFE) under high electron beam irradiations from linear accelerator for clinical applications was investigated. The irradiations were carried out using high electron beams (6 to 18 MeV) from a linear accelerator Varian, C linac 2300C/D, for clinical practice purpose. The electron irradiations were obtained by using the water solid in order to guarantee electronic equilibrium conditions. Field shaping for electron beams was obtained with electron cones. Glow curve and other thermoluminescent characteristics of CaSO 4 :Dy+PTFE were conducted under high electron beams irradiations. The thermoluminescent response of the pellets showed and intensity peak centered at around 235 C. Thermoluminescent response of CaSO 4 :Dy+PTFE as a function of high electron absorbed dose showed a linearity in a wide range. To obtain reproducibility characteristic, a set of pellets were exposed repeatedly for the same electron absorbed dose. The results obtained in this study can suggest the applicability of CaSO 4 :Dy+PTFE pellets for high electron beam dosimetry, provided fading is correctly accounted for. (Author)

Thermoluminescent and dosimetric properties of anion-defective a-Al2O3 single crystals with filled deep traps

International Nuclear Information System (INIS)

Kortov, V.S.; Milman, I.I.; Nikiforov, S.V.

2002-01-01

Some new experimental results illustrating the effect of deep traps on luminescent and dosimetric properties of anion-defective single crystals of a-Al 2 O 3 have been described. It was found that deep traps had an electronic origin. They were filled thanks to the photoionisation of F-centres and their filling was accompanied by the conversion of FF+ centres. The experiments revealed an interactive interaction of deep trapping centres. A model taking into account the thermal ionisation of excited states of F-centres was proposed. This model describes the trap filling process and mechanisms of the radio-, photo- and thermoluminescence, TSC and TSEE of the crystals under study. The sensitivity of TLD-500 detectors based on anion-defective a-Al 2 O 3 equalised when deep trapping centres were filled. (author)

Development of a multichannel dosimeter for radiotherapy; Desenvolvimento de um dosimetro multicanal para radioterapia

Energy Technology Data Exchange (ETDEWEB)

Menezes, Claudio Jose Mesquita

2000-06-01

In radiotherapy, verification of the patient dose is of great important for the success of the treatment. Uncertainties in the evaluation of this dose can produce serious complications such as the loss of the control of the disease and damage to normal tissue. Semiconductor detectors present advantages over other types of radiation detectors such as ionization chambers and thermoluminescent dosimeters including small dimensions, high sensitivity and fast response. In this work, a multichannel dosimetric system is linear with dose, for a 6 MV x-ray beam and also with a beam of cobalt-60 gamma rays. The coefficients of determination of the calibration curves were better then 0,9998 in all cases. The four sensors presented similar response with the dose for different field sizes. The variation of the response was smaller than 1%. In a related study, depth dose was measured, and the results showed a good agreement compared to theoretical values. The angular response of the detectors showed a variation of 7% for angles of 45 deg C. Using the Anderson Random phantom, dose at the isocenter was determined from measurements of the surface dose. From the results obtained it can be concluded that the dosimetric system developed is adequate for the evaluation of many parameters in radiation fields used in radiotherapy. This system can be used to measure the patient entrance dose under treatment conditions, and the equipment can be used in the radiotherapy quality assurance program. (author)

Thermoluminescence of pyramid stones

International Nuclear Information System (INIS)

Gomaa, M.A.; Eid, A.M.

1982-01-01

It is the aim of the present study to investigate some thermoluminescence properties of pyramid stones. Using a few grammes of pyramid stones from Pyramids I and II, the TL glow peaks were observed at 250 and 310 0 C, respectively. The TL glow peaks of samples annealed at 600 0 C, then exposed to 60 Co γ-rays were observed at 120, 190 and 310 0 C, respectively. The accumulated dose of natural samples is estimated to be around 310 Gray (31 krad). By assuming an annual dose is 1 mGy, the estimated age of pyramid stones is 0.31 M year. (author)

Thermoluminescence of pyramid stones

Energy Technology Data Exchange (ETDEWEB)

Gomaa, M A; Eid, A M [Atomic Energy Establishment, Cairo (Egypt)

1982-01-01

It is the aim of the present study to investigate some thermoluminescence properties of pyramid stones. Using a few grammes of pyramid stones from Pyramids I and II, the TL glow peaks were observed at 250 and 310/sup 0/C, respectively. The TL glow peaks of samples annealed at 600/sup 0/C, then exposed to /sup 60/Co ..gamma..-rays were observed at 120, 190 and 310/sup 0/C, respectively. The accumulated dose of natural samples is estimated to be around 310 Gray (31 krad). By assuming an annual dose is 1 mGy, the estimated age of pyramid stones is 0.31 M year.

Meios e fins do desenvolvimento para Celso Furtado

Directory of Open Access Journals (Sweden)

Fabio Antonio de Campos

2014-10-01

Full Text Available O objetivo desse artigo é expor o conceito de desenvolvimento para Celso Furtado. Para tanto, nos interessa apresentar o desenvolvimento nacional como um fim em sua abordagem sobre a formação social brasileira Para atingir tal estágio, os meios para o autor seriam assegurados por um típico desenvolvimento capitalista. Dentro dessa problemática, mostraremos também o alcance e os limites dessa concepção para o caráter dependente e subdesenvolvido do capitalismo brasileiro.

O desafio político do desenvolvimento sustentado

OpenAIRE

Guimarães,Roberto P.

1995-01-01

A unanimidade que hoje parece haver em favor do desenvolvimento sustentado contrasta com a ausência de iniciativas políticas significativas para transformar as instituições econômicas, sociais e políticas que estão comprometidas com o estilo vigente de desenvolvimento. Em particular, há uma patente contradição entre o discurso antiestatista hegemônico e as exigências do desenvolvimento sustentado, que incluem um Estado ainda mais forte, em suas capacidades reguladoras e de planificação, que o...

N.R.P.B.'s new record-keeping service and thermoluminescent dosemeter

International Nuclear Information System (INIS)

Dennis, J.A.; Marshall, T.O.; Shaw, K.B.; Kendall, G.M.

1977-01-01

With the approval of the Health and Safety Executive the National Radiological Protection Board is introducing a radiation dose record keeping service in association with a thermoluminescent dosimeter. This service will relieve employers of the responsibility for maintaining and keeping dose records. Both the record keeping and dosimeter systems are described, including the documents which will be produced for employers. The thermoluminescent dosimeter is more accurate and less sensitive to environmental factors than the film dosimeter, which it replaces. It also reduces the consumption of materials and, with automated processing, is labour saving. (author)

Sensitization by UV light of α-Al2O3:C polycrystalline detectors

International Nuclear Information System (INIS)

Meira B, L. C.; Rubio F, H.; Neres de A, E.; Santos, A.

2014-08-01

This paper describes an increase in sensitivity to gamma and beta radiation on α-Al 2 O 3 :C polycrystalline detector, which has been produced by a sol-gel process, following previous exposure to ultraviolet light. The increased sensitivity of the detector as a function of the exposure time and ultraviolet wavelength was studied. Since the main luminescent centers have emission peaks at different wavelengths, selective measurements of thermoluminescent emission intensity were done, in order to investigate the possible conversion of centers as a result of the exposition to ultraviolet light. Experimental results indicate that the nature and parameters of the luminescent centers in α-Al 2 O 3 :C sol-gel material can be very different of those in α-Al 2 O 3 :C single crystal. (author)

Radiation effects in the polycarbonate of bisphenol-A. Thermoluminescence electron spin resonance and charged particle track studies

International Nuclear Information System (INIS)

Edmonds, E.A.

1978-09-01

A detailed investigation is presented of the thermoluminescence observable above room temperature from the polycarbonate of bisphenol-A after its exposure to different radiations. A correlation study is described by which features of the complex thermoluminescence glow curve from a commercial grade of the polycarbonate of bisphenol-A are related to the etchability of charged particle damage trails and the radiogenic ESR signal. A model is presented whereby the etchability of charged particle damage trails is associated with chain scission caused by the high local dose of radiation in the vicinity of the trajectories of charged particles. Methods by which activation constants controlling the thermoluminescence glow curve can be evaluated are discussed and results are presented. It is concluded that glow peaks associated with the ESR signal or enhanced etchability are related to small-scale motions in the molecular matrix of the polycarbonate of bisphenol-A. These motions are thermally activated in accord with the simple Boltzmann relation usually incorporated into theories of thermoluminescence. Another component glow peak of the thermoluminescence glow curve is shown to be associated with the glass-rubber transition in the polycarbonate of bisphenol-A. Different features of the thermoluminescence glow curve can be related to relaxations of the polymer matrix and decomposition of the matrix. It is confirmed that the dominant bulk effect of radiation in the polycarbonate of bisphenol-A exposed to large doses of radiation is chain scission. (author)

Retrospective dosimetry assessment using the 380 deg. C thermoluminescence peak of tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Secu, C.E. [National Institute for Materials Physics, PO Box MG-7, 77125 Bucharest-Magurele (Romania); Cherestes, M. [Dozimed Ltd., Dosimetry Laboratory, 77125 Bucharest-Magurele (Romania); Secu, M., E-mail: msecu@infim.ro [National Institute for Materials Physics, PO Box MG-7, 77125 Bucharest-Magurele (Romania); Cherestes, C.; Paraschiva, V. [Dozimed Ltd., Dosimetry Laboratory, 77125 Bucharest-Magurele (Romania); Barca, C. [Faculty of Physics, University of Bucharest, 77125 Bucharest-Magurele (Romania)

2011-10-15

The thermoluminescence (TL) response to gamma-ray irradiation of tooth enamel is reported. The tooth enamel was separated from dentine by using mechanical and physico-chemical procedures followed by grinding (grain size {approx}100 {mu}m) and etching. The TL was attributed to the recombination of CO{sub 2}{sup -} radicals incorporated into or attached to the surface of hydroxyapatite crystals. The growth of the {approx}380 deg. C TL peak with absorbed dose was examined with irradiated tooth enamel samples and reconstructed doses evaluated for tooth enamel samples from four human subjects. - Highlights: > Thermoluminescence response after gamma-ray irradiation of tooth enamel was investigated. > Thermoluminescence was attributed to the recombination of CO{sub 2}{sup -} radicals. > CO{sub 2}{sup -} radicals are produced inside or at the surface of hydroxyapatite crystals. > From the growth of the 380C peak reconstructed doses have been evaluated.

Thermoluminescence in alkali halides irradiated at 80K; Termoluminiscencia en haluros alcalinos irradiados a 80K

Energy Technology Data Exchange (ETDEWEB)

Jimenez de Castro, M

1978-07-01

The thermoluminescence, the thermally stimulated currents and the thermal stability of the F centres induced in pure NaCl and KC1 crystals by X irradiation at 80K have been studied in detail, In the range between 80 and 300K. The thermoluminescent processes induced by illumination at 80K with F light in samples previously irradiated at room temperature has also been studied. It has been clearly observed the existence of thermoluminescent processes due to electrons and holes thermally released from traps, in which the F centres are not involved. The existence of hole-F centre recombination has not been observed. There are several thermoluminescent processes in both materials which are scribed to the recombination of F centres with mobile interstitial halogen atoms thermally released from traps, which are likely monovalent impurities in this temperature interval. The light emitting stage in these processes is originated by the formation of self trapped excitons. (Author) 66 refs.

Thermoluminescence and cathodoluminescence studies of calcite and MgO: surface defects and heat treatment

International Nuclear Information System (INIS)

Goeksu, H.Y.; Brown, L.M.

1988-01-01

Some of the problems which preclude accurate thermoluminescence (TL) dating of geologically formed calcite stem from different sample pre-treatment procedures, such as grinding, drilling or pre-heating. It has long been known that grinding can introduce spurious TL in calcite, but there have been wide differences of opinion as to the magnitude of the influence and its importance. Therefore, various grinding and acid-washing procedures have been suggested to avoid spurious thermoluminescence. Various models have been developed to explain the mechanism. We have studied the changes in thermoluminescence (TL) and cathodoluminescence (CL) properties as well as in the spectral composition of the glow from calcite and MgO due to surface defects and heat treatment. It is found that both laboratory heat treatment and surface indents give rise to changes in TL efficiency. (author)

Preliminary research on thermoluminescence application in complicated geological situation

International Nuclear Information System (INIS)

Gong Gelian; Liu Chunsheng

2003-01-01

Thermoluminescent phenomenon resulting from two kinds of complicated geological situation, Ordos Basin and Huainan deposits in Anhui Province, is studied by the means of thermoluminescence counting method. It is shown that: (1) there are no apparent abnormalities of natural TL detected from the rock samples selected in the first 1000 meter depth of the Earth, and these natural TL are accumulated through natural radiation effects; (2) the natural TL shows statistically obvious reducing trends for the rock samples selected under the 2000 meter depth, and even no detectable TL is found for those rocks selected at 4000 meter depth. (3) the natural TL peaks corresponding to high temperature generally shift to the direction of higher temperature for the quartz-related rock samples, and several thermal events which occurred during the geological times might be responsible for this case

Thermoluminescence dating of pleistocene sediments

International Nuclear Information System (INIS)

Poupeau, G.; Souza, J.H.

1984-01-01

After a short introduction on recent trends in quaternary geochronology, this article focuses on the thermoluminescence (TL) dating of sediments, whose principles, present limits and prospects are discussed. Results are presented for TL behavior of sands from various geological contexts in Brazil. They show that the coarse (approx. 100-200 μm) quartz fraction of coastal and intracontinental, eolian and fluvial - type deposits, might be datable by TL from the upper Holocene to at least the base of the upper Pleistocene, with a precision of +- 10-15%. (Author) [pt

Thermoluminescence dating of pleistocene sediments

International Nuclear Information System (INIS)

Poupeau, G.; Souza, J.H.; Rivera, A.

1984-01-01

After a short introduction on recent trends in quaternary geochronology, this article focuses on the thermoluminescence dating of sediments, whose principles and present limits and prospects are discussed. Results are presented for the TL behaviour of sands from various geological contexts in Brazil. They show that the coarse (approx. 100-200μm) quartz fraction of coastal and intra continental, eolian and fluvial-type deposits, might be datable by TL from the upper Holocene to at least the basis of the upper Pleistocene, with a precision of + - 10-15%. (Author) [pt

Models and methods in thermoluminescence

International Nuclear Information System (INIS)

Furetta, C.

2005-01-01

This work contains a conference that was treated about the principles of the luminescence phenomena, the mathematical treatment concerning the thermoluminescent emission of light as well as the Randall-Wilkins model, the Garlick-Gibson model, the Adirovitch model, the May-Partridge model, the Braunlich-Scharman model, the mixed first and second order kinetics, the methods for evaluating the kinetics parameters such as the initial rise method, the various heating rates method, the isothermal decay method and those methods based on the analysis of the glow curve shape. (Author)

Models and methods in thermoluminescence

Energy Technology Data Exchange (ETDEWEB)

Furetta, C. [ICN, UNAM, A.P. 70-543, Mexico D.F. (Mexico)

2005-07-01

This work contains a conference that was treated about the principles of the luminescence phenomena, the mathematical treatment concerning the thermoluminescent emission of light as well as the Randall-Wilkins model, the Garlick-Gibson model, the Adirovitch model, the May-Partridge model, the Braunlich-Scharman model, the mixed first and second order kinetics, the methods for evaluating the kinetics parameters such as the initial rise method, the various heating rates method, the isothermal decay method and those methods based on the analysis of the glow curve shape. (Author)

Evaluation of the response of thermoluminescent detectors in clinical beams dosimetry using different phantoms; Avaliacao da resposta de detectores termoluminescentes na dosimetria de feixes clinicos utilizando diferentes objetos simuladores

Energy Technology Data Exchange (ETDEWEB)

Matsushima, Luciana Cardoso

2010-07-01

Radiotherapy is one of the three principal treatment modalities used in the treatment of malignant diseases such as cancer, the other two are chemotherapy and radiosurgery. In contrast to other medical specialties that rely mainly on the clinical knowledge and experience of medical specialists, radiotherapy, with its use of ionizing radiation in treatment of cancer, relies heavily on modern technology and the collaborative efforts of several professionals whose coordinated team approach greatly influences the outcome of the treatment. In the area of clinical dosimetry, an efficient and accurate calibration of the radiation beam ensures knowledge of the radiation dose delivered to the patient, allowing thus the success of radiotherapy. This study aims to compare the thermoluminescent response of calcium sulfate doped with dysprosium (CaSO{sub 4}:Dy) dosimeters produced by IPEN (6 mm in diameter and 0,8 mm tick) with the response of lithium fluoride (3,15 x 3,15 x 0,9 mm{sup 3}) doped with magnesium and titanium (LiF:Mg,Ti) in dosimetry of clinical photons (6 and 15 MV) and electrons beams (6 and 9 MeV) using solid water (RMI-457), water and PMMA phantoms. Initially, the dose-response curves were obtained for irradiation in cobalt-60 gamma radiation source in air (PMMA plates) and under electronic equilibrium conditions and for clinical electrons and photons beams at depth of maximum dose. The sensitivities of the thermoluminescent dosimeters were also evaluated and the values of their reproducibilities and intrinsic efficiency were determined for the response to different types of phantoms and radiation energy. The obtained results indicate that the main advantage of CaSO{sub 4}:Dy dosimeters is the enhanced sensitivity to radiation doses measured for {sup 60}Co, photons and electrons beams, thus representing a viable alternative for application in dosimetry in the radiotherapy area. (author)

Natural dose level determination at Johor State with thermoluminescence dosimetry

International Nuclear Information System (INIS)

Ahmad Termizi Ramli; Yusof Jasman

1995-01-01

This paperwork presented the results of using thermoluminescence dosimetry (TLD) method in measuring background dose level, which is done at State of Johor, South Malaysia. The problems faced also discussed

Storage Telemetry of Radionuclide Tracers by Implantable Thermoluminescent Dosimeters

DEFF Research Database (Denmark)

Bojsen, J.; Møller, U.; Christensen, Poul

1977-01-01

A storage telemetrical method using thermoluminescent (TL) dosimeters for long-term measurements of incorporated radioactive substances in unrestrained rats has been developed. The system has been used in combination with radiotelemetrical registration of the circadian temperature rhythm. By sequ...

Thermoluminescence dosimetry in quality imaging in CR mammography systems

Energy Technology Data Exchange (ETDEWEB)

Gaona, E.; Franco E, J.G. [UAM-Xochimilco, 04960 Mexico D.F. (Mexico); Azorin N, J. [UAM-Iztapalapa, 09340 Mexico D.F. (Mexico); Diaz G, J.A.I. [CICATA, Unidad Legaria, Av. Legaria 694, 11599 mexico D.F. (Mexico); Arreola, M. [Department of Radiology, Shands Hospital at UF, PO Box 100374, Gainesville, FL 32610-0374 (United States)

2006-07-01

The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

Thermoluminescence dosimetry in quality imaging in CR mammography systems

International Nuclear Information System (INIS)

Gaona, E.; Franco E, J.G.; Azorin N, J.; Diaz G, J.A.I.; Arreola, M.

2006-01-01

The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

Thermoluminescence characterization of CVD diamond film exposed to UV and beta radiation

International Nuclear Information System (INIS)

Barboza-Flores, M.; Melendrez, R.; Gastelum, S.; Chernov, V.; Bernal, R.; Cruz-Vazquez, C.; Brown, F.; Pedroza-Montero, M.; Gan, B.; Ahn, J.; Zhang, Q.; Yoon, S.F.

2003-01-01

Thermoluminescence (TL) properties of diamond films grown by microwave and hot filament CVD techniques were studied. The main purpose of the present work was to characterize the thermoluminescence response of diamond films to ultraviolet and beta radiation. The thermoluminescence excitation spectrum exhibits maximum TL efficiency around 210-215 nm. All samples presented a glow curve composed of at least one TL peak and showed regions of linear as well as supralinear behavior as a function or irradiation dose. The linear dose dependence was found for up to sixteen minutes of monochromatic UV irradiation and 300 Gy for beta irradiated samples. The activation energy and the frequency factor were determined and found in the range of 0.33-1.7 eV and 5.44 x 10 2 -5.67 x 10 16 s -1 , respectively. The observed TL performance is reasonable appropriate to justify further investigation of diamond films as radiation dosimeters keeping in mind that diamond is an ideal TL dosemeter since it is tissue-equivalent and biological compatible. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Burnout detector design for heat transfer experiments

International Nuclear Information System (INIS)

Dias, H.F.

1992-01-01

This paper describes the design of an burnout detector for heat transfer experiments, applied during tests for optimization of fuel elements for PWR reactors. The burnout detector avoids the fuel rods destruction during the experiments at the Centro de Desenvolvimento da Tecnologia Nuclear. The detector evaluates the temperature changes over the fuel rods in the temperature changes over the fuel rods in the area where the burnout phenomenon could be anticipated. As soon as the phenomenon appears, the system power supply is turned off. The thermal Circuit No. 1, during the experiments, had been composed by nine fuel rods feed parallelly by the same power supply. Fine copper wires had been attached at the centre and at the ends of the fuel rod to take two Wheat stone bridge arms. The detector had been applied across the bridge diagonals, which must be balanced the burnout excursion can be detected as a small but fast increase of the signal over the detector. Large scale experiments had been carried out to compare the resistance bridge performance against a thermocouple attached through the fuel rod wall. These experiments had been showed us the advantages of the first method over the last, because the bridge evaluates the whole fuel rod, while the thermocouple evaluates only the area where it had been attached. (author)

The thermoluminescence of carp otoliths: A fingerprint in ...

African Journals Online (AJOL)

This paper reports a pilot study on the thermoluminescence (TL) of carbonate minerals of carp otoliths from the heavily polluted Baiyangdian Lake (BYD) in Hebei Province and non-polluted Miyun Water Reservoir (MY) in Beijing Municipality of China. Analyses on trace elements of otoliths and water show that the heavy ...

Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Lead Reflected Pulse of the CEA Valduc SILENE Critical Assembly

International Nuclear Information System (INIS)

Miller, Thomas Martin; Celik, Cihangir; Isbell, Kimberly McMahan; Lee, Yi-kang; Gagnier, Emmanuel; Authier, Nicolas; Piot, Jerome; Jacquet, Xavier; Rousseau, Guillaume; Reynolds, Kevin H.

2016-01-01

This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 13, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube, and the Rocky Flats detects neutrons via charged particles produced in a thin 6 LiF disc, depositing energy in a Si solid-state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Polyethylene Reflected Pulse of the CEA Valduc SILENE Critical Assembly

International Nuclear Information System (INIS)

Miller, Thomas Martin; Celik, Cihangir; McMahan, Kimberly L.; Lee, Yi-kang; Gagnier, Emmanuel; Authier, Nicolas

2016-01-01

This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 19, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube and the Rocky Flats detects neutrons via charged particles produced in a thin "6LiF disc depositing energy in a Si solid state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Polyethylene Reflected Pulse of the CEA Valduc SILENE Critical Assembly

Energy Technology Data Exchange (ETDEWEB)

Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McMahan, Kimberly L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [French Atomic Energy Commission (CEA), Saclay (France); Gagnier, Emmanuel [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette; Authier, Nicolas [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Piot, Jerome [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Jacquet, Xavier [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Rousseau, Guillaume [French Atomic Energy Commission (CEA), Salives (France). Valduc Centre for Nuclear Studies; Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

2016-09-01

This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 19, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube and the Rocky Flats detects neutrons via charged particles produced in a thin ⁶LiF disc depositing energy in a Si solid state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

Neutron Activation Foil and Thermoluminescent Dosimeter Responses to a Lead Reflected Pulse of the CEA Valduc SILENE Critical Assembly

Energy Technology Data Exchange (ETDEWEB)

Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Isbell, Kimberly McMahan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Yi-kang [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Gagnier, Emmanuel [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Authier, Nicolas [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Piot, Jerome [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Jacquet, Xavier [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Rousseau, Guillaume [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA-Saclay), Gif-sur-Yvette (France); Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

2016-09-01

This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 13, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. The CIDAS detects gammas with a Geiger-Muller tube, and the Rocky Flats detects neutrons via charged particles produced in a thin ⁶LiF disc, depositing energy in a Si solid-state detector. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

Thermoluminescence properties of Eu-doped and Eu/Dy-codoped Sr2 Al2 SiO7 phosphors.

Science.gov (United States)

Jadhaw, Akhilesh; Sonwane, Vivek D; Gour, Anubha S; Jha, Piyush

2017-11-01

We report the thermoluminescence properties of Sr 1.96 Al 2 SiO 7 :Eu 0.04 and Sr 1.92 Al 2 SiO 7 :Eu 0.04 Dy 0.04 phosphors. These phosphors were prepared by a high-temperature solid-state reaction method. The prepared phosphors were characterized by X-ray diffraction. A 254 nm source was used for ultraviolet (UV) irradiation and a 60 Co source was used for γ-irradiation. The effect of heating rate and UV-exposure were examined. The thermoluminescence temperature shifts to higher values with increasing heating rate and thermoluminescence intensity increases with increasing UV exposure time. The trapping parameters such as activation energy (E), order of kinetics and frequency factor (s) were calculated by peak shape method. The effect of γ- and UV-irradiation on thermoluminescence studies was also examined. Copyright © 2017 John Wiley & Sons, Ltd.

CONHECIMENTO: UM FATOR DE DESENVOLVIMENTO ORGANIZACIONAL

Directory of Open Access Journals (Sweden)

Adilson dos Santos Morais

2017-09-01

Full Text Available Cada vez mais, criar conhecimento útil para atuar em uma posição de vantagem competitiva, orientado para o desenvolvimento organizacional e valorizando o capital humano tem-se demonstrato uma estratégia eficaz. O presente artigo busca apresentar a importância do conhecimento para o desenvolvimento das organizações em âmbito geral com destaque para as comunidades de prática. Esse conhecimento é derivado das interações desenvolvidas em processos de aprendizagem que ocorrem no ambiente organizacional. Para este, realizou-se um estudo teórico, descritivo, que tem como procedimento a pesquisa bibliográfica. Deste modo, apresenta como resultado deste trabalho a evidência de que existem poucos resultados divulgados sobre retorno financeiro e os benefícios dos investimentos realizados no capital intelectual humano pelas organizações. Porém, o conhecimento agrega valor à organização aumentando o valor do capital intelectual e as literaturas sobre o conhecimento e desenvolvimento organizacional consideram o capital intelectual o fator chave para a melhoria nos sistemas estratégicos. Destaca-se que esta contribuição poderá instigar cada vez mais a criação de conhecimento como fator de reconhecimento humano e de desenvolvimento das organizações.

Phosphor for thermoluminescent type radiation dosimeter

International Nuclear Information System (INIS)

Nada, N.; Yamashita, T.

1975-01-01

This has the accumulation effect of radiation energy and is mainly used as the element for thermoluminescent type radiation dosimeters. It has as the principal constituent a phosphor consisting of calcium sulfate as the principal constituent and other impurity elements such as dysprosium, thulium and the like. It is more sensitive by the order of 1 to 2 or more figures than the conventional ones and is excellent in the retention of absorbed radiation energy. (U.S.)

A pocket type thermoluminescent personnel dosimeter

International Nuclear Information System (INIS)

Vora, K.G.; Nagpal, J.S.; Pendurkar, H.K.; Gangadharan, P.

1979-01-01

A pocket type thermoluminescent personnel dosemeter using CaSO 4 : Dy phosphor is described. Two glass capillaries containing the phosphor are fitted into a plastic tube and covered by a cylindrical filter. The combination is fitted into an ink barrel of a fountain pen. The response of this Dy glass dosimeter was studied for various incident photon energies. A uniform response over the energy range from 33 keV to 1250 keV is achieved. (A.K.)

Application of numerical analysis methods to thermoluminescence dosimetry

International Nuclear Information System (INIS)

Gomez Ros, J. M.; Delgado, A.

1989-01-01

This report presents the application of numerical methods to thermoluminescence dosimetry (TLD), showing the advantages obtained over conventional evaluation systems. Different configurations of the analysis method are presented to operate in specific dosimetric applications of TLD, such as environmental monitoring and mailed dosimetry systems for quality assurance in radiotherapy facilities. (Author) 10 refs

Desenvolvimento e sociologia: uma aproximação necessária

Directory of Open Access Journals (Sweden)

Alessandro André Leme

2015-08-01

Full Text Available ResumoO debate acerca do desenvolvimento na América Latina e no Brasil em particular revelou-se como um dos temas proeminentes do pensamento sociopolítico e econômico brasileiro. As interpretações do Brasil a partir da temática do desenvolvimento ganham força a partir da década de 1930, porém, será após a Segunda Guerra Mundial, com a intensificação da industrialização e a modernização da sociedade capitalista brasileira, que o tema adquire centralidade na sociologia/ciência política. Por outro lado, as discussões acerca do Estado e do desenvolvimento estão intimamente ligadas ao desenvolvimento do capitalismo brasileiro, ou seja, configura uma tríade que simultaneamente evidencia tanto um tipo historicamente determinado de Estado como um tipo particular de desenvolvimento econômico e social do país. O desenvolvimento do Brasil caracteriza-se por um embate entre o mercado e o Estado, sendo a influência desse último fundante para o padrão de desenvolvimento pretendido no país. Propomos a análise do processo de desenvolvimento como forma de revisitar o debate teórico e conceitual produzido sobre a temática no país, assim como investigar o movimento histórico, econômico e político adotado pelo Brasil como estratégia para o desenvolvimento nos anos 1990.

Thermoluminescence dosimetry of gamma rays from the fallout of the Semipalatinsk nuclear tests

International Nuclear Information System (INIS)

Takada, J.; Hoshi, M.; Endo, S.; Yamamoto, M.; Nagatomo, T.; Gusev, B.I.; Rozenson, R.I.; Apsalikov, K.N.; Tchaijunusova, N.J.

1996-01-01

Field missions were sent to several settlements near the Semipalatinsk nuclear test site out in order to investigate dosimetry for the residents in 1995. The results of measurements of environmental radiation doses and thermoluminescence dosimetry in some villages near the Semipalatinsk nuclear test site are presented. The radiation levels in several villages are the natural background level in 1995, 6 years after the final nuclear explosion. On the other hand, thermoluminescence dosimetry revealed significant radiation exposure to residents in this area due to nuclear tests. (author)

Image in nuclear dosimetry using thermoluminescent dosimetry

International Nuclear Information System (INIS)

Guinsburg, G.; Matsuoka, M.; Watanabe, S.

1987-01-01

A low cost methodology to produce images of internal sick organs by radioisotopic intake, is presented. Dosimetries of thermoluminescent material and Teflon (ratio:50%) in bidimensional matrix shape are used with a Pb collimator. This collimator-bidimensional matrix system was tested ''in vivo'' and in thyroid phantoms using 99m Tc. A comparative evaluation between this method and the scintigraphy one is presented. (M.A.C.) [pt

Thermoluminescent properties of CaSO4:Dy prepared by precipitation method

International Nuclear Information System (INIS)

Roman, J.; Rivera, T.; Azorin, J.

2009-10-01

This paper reports the synthesis and thermoluminescent (Tl) characterization of CaSO 4 :Dy obtained by the precipitation method. Thermoluminescent CaSO 4 :Dy powder and Teflon (PTFE) were mixed in order to obtain samples in pellets form. Samples of CaSO 4 :Dy were exposed to a radiation gamma source of 60 Co and 90 Sr beta particles. Tl response of CaSO 4 :Dy showed a glow curve with two peaks centered at around 164 and 302 C. Tl phosphor showed a good linearity in the range from 0.5 to 30 Gy. Fading of the Tl information was 5.19 % in 37 days and presented a standard deviation of 4% for reproducibility. (Author)

Thermoluminescence dating of late Devensian loesses in southern England

International Nuclear Information System (INIS)

Wintle, A.G.

1981-01-01

The results are reported of thermoluminescence dating of six relatively recent deposits of loess-like material from southern Britiain between the Scilly Isles and Kent. The dates have been obtained on the loess itself and confirm the ages as being late Devensian. (U.K.)

A theoretical description of complex thermoluminescence curves: 2

International Nuclear Information System (INIS)

Kantorovich, L.N.; Fogel, G.M.

1989-01-01

Thermoluminescence kinetics is discussed using a model with one type of recombination centre and an arbitrary number of trapping centre types, assuming that electron retrapping is dominant. A distinctive feature of the suggested method is that an integral equation is obtained for the one-time function z(t) through which both the intensity of the thermoluminescence curve (TLC) and the concentration of charge carriers are expressed. Using a series of approximations, which are analysed in detail, analytical solutions of the integral equation are obtained for an arbitrary elementary peak in a complex TLC consisting of a number of slightly overlapping peaks. The comparison of the theoretical results with the numerical ones obtained by the Runge-Kutta method shows that the obtained analytical expression is precise for the first peak and describes the following TLC peaks satisfactorily. The possibility of using the results of the present study for computer division of a complex TLC into elementary components, even in the case of considerably overlapping peaks, is also discussed. (author)

An experimental system for thermoluminescent dosimetry

International Nuclear Information System (INIS)

Perry, K.E.G.; George, E.

1965-08-01

A thermoluminescent dosimeter (T.L.D.) reader has been developed for experimental investigations on the use of lithium fluoride for 'finger tip' dosimetry. The design of the reader is based on the maximum use of standard electronic units in the A.E.R.E. Type 2000 series but some new unit development has been necessary. The reader gives improved experimental facilities over present commercially-available designs. The technique for 'finger-tip' dosimetry is described and the initial experimental results are given. (author)

Improving neutron dosimetry using bubble detector technology

International Nuclear Information System (INIS)

Buckner, M.A.

1993-02-01

Providing accurate neutron dosimetry for a variety of neutron energy spectra is a formidable task for any dosimetry system. Unless something is known about the neutron spectrum prior to processing the dosimeter, the calculated dose may vary greatly from that actually encountered; that is until now. The entrance of bubble detector technology into the field of neutron dosimetry has eliminated the necessity of having an a priori knowledge of the neutron energy spectra. Recently, a new approach in measuring personnel neutron dose equivalent was developed at Oak Ridge National Laboratory. By using bubble detectors in combination with current thermoluminescent dosimeters (TLDs) as a Combination Personnel Neutron Dosimeter (CPND), not only is it possible to provide accurate dose equivalent results, but a simple four-interval neutron energy spectrum is obtained as well. The components of the CPND are a Harshaw albedo TLD and two bubble detectors with theoretical energy thresholds of 100 key and 1500 keV. Presented are (1) a synoptic history surrounding emergence of bubble detector technology, (2) a brief overview of the current theory on mechanisms of interaction, (3) the data and analysis process involved in refining the response functions, (4) performance evaluation of the original CPND and a reevaluation of the same data under the modified method, (5) the procedure used to determine the reference values of component fluence and dose equivalent for field assessment, (6) analysis of the after-modification results, (7) a critique of some currently held assumptions, offering some alternative explanations, and (8) thoughts concerning potential applications and directions for future research

Performance tests on the NRPB thermoluminescent dosemeter

CERN Document Server

Shaw, K B

1977-01-01

Performance tests on the thermoluminescent dosemeter, designed at NRPB for use in the automated personal dosimetry system, are described. An ultra-thin lithium borate dosemeter has been developed for skin absorbed dose measurement. The X-ray, gamma-ray and beta-ray energy response of the dosemeter has been investigated and the angular response for the dosemeter has been examined. The annealing, read-out and stabilisation procedures for the dosemeter are described.

Spatially-resolved thermoluminescence from snail opercula using an EMCCD

DEFF Research Database (Denmark)

Duller, G.A.T.; Kook, Myung Ho; Stirling, R.J.

2015-01-01

In recent years opercula of the snail species Bithynia tentaculata have been shown to emit thermoluminescence (TL) signals that can be used to determine equivalent dose, and may be capable of dating events throughout the entire Quaternary period. Concentric growth lines are a notable feature of a...

CERVEJA ARTESANAL E DESENVOLVIMENTO REGIONAL EM SANTA CATARINA (BRASIL)

OpenAIRE

Valdinho Pellin; Oklinger Mantovaneli Jr.

2016-01-01

Discussões relacionadas ao fortalecimento do desenvolvimento regional tem estimulado um debate em relação a contribuições que Indicações Geográficas (IGs) podem oferecer ao desenvolvimento. IGs se constituem em elemento de identificação de produtos ou serviços com seus territórios e podem oferecer contribuições importantes para o desenvolvimento regional, agregando valor aos produtos, facilitando o acesso a novos mercados e valorizando tradições locais. Este artigo procura discutir a importân...

Observations on some thermoluminescence emission centres in geological quartz

International Nuclear Information System (INIS)

Scholefield, R.B.; Prescott, J.R.; Fox, P.J.; Franklin, A.D.

1994-01-01

We report measurements of three-dimensional thermoluminescence emission spectra of samples of geological quartz, derived from Australian sediments. The emphasis is on peaks of particular practical interest for thermoluminescence sediment dating, viz. the 110 o C peak, which is used for pre-dose dating and the peak at 325 o C, which is of significance for partial and selective bleach techniques and for optically stimulated luminescence (OSL) dating. Because the 325 o C peak can be bleached to essentially zero, it can be isolated in a given spectrum by subtracting the bleached spectrum from the unbleached spectrum. By including both peaks in the same spectrum, it is demonstrated that they do not emit at the same wavelength, although this does not necessarily mean that the emission is from different emission centres. The 375 o C peak, which is important in total bleach methods, emits at a distinguishable wavelength. The use of bleaching and subtraction in practical dating is discussed. (Author)

Comparative study of thermoluminescence detection methods for irradiated spices

International Nuclear Information System (INIS)

Kawamura, Y.; Kojima, K.; Sugita, T.; Yamada, T.; Saito, Y.

1995-01-01

The thermoluminescence (TL) detection methods for irradiated spices were compared using spice samples obtained on the Japanese market, irradiated at doses of 1, 5, 10 and 30 kGy and stored for 1 year before analysis. The TL intensities of irradiated spices were stable for 1 year after irradiation. Measurement with whole samples failed to identify irradiated samples. Minerals were separated from spices in sodium tungstate saturated solution and/or sodium polytungstate solution. The TL intensity of minerals which had undergone irradiation was significantly increased for all samples. However, the ranges of TL intensity of irradiated and unirradiated samples overlapped. Clear discrimination has been obtained between the TL ratios of irradiated and unirradiated spices by using normalized measurement with reirradiation. The detection limit in terms of irradiation dose is 1 kGy even in a sample that has been irradiated 1 year prior to analysis. Normalization is the best technique currently available for thermoluminescence analysis to identify irradiated spices

Sensitization by UV light of α-Al{sub 2}O{sub 3}:C polycrystalline detectors

Energy Technology Data Exchange (ETDEWEB)

Meira B, L. C.; Rubio F, H.; Neres de A, E. [Centro de Desenvolvimento da Tecnologia Nuclear - CNEN, Laboratorio de Dosimetria Termoluminicente, Av. Antonio Carlos 6627, Campus UFMG, CEP 31270-901, Belo Horizonte (Brazil); Santos, A., E-mail: hrf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear - CNEN, Laboratorio de Microesferas Gel, Av. Antonio Carlos 6627, Campus UFMG, CEP 31270-901, Belo Horizonte (Brazil)

2014-08-15

This paper describes an increase in sensitivity to gamma and beta radiation on α-Al{sub 2}O{sub 3}:C polycrystalline detector, which has been produced by a sol-gel process, following previous exposure to ultraviolet light. The increased sensitivity of the detector as a function of the exposure time and ultraviolet wavelength was studied. Since the main luminescent centers have emission peaks at different wavelengths, selective measurements of thermoluminescent emission intensity were done, in order to investigate the possible conversion of centers as a result of the exposition to ultraviolet light. Experimental results indicate that the nature and parameters of the luminescent centers in α-Al{sub 2}O{sub 3}:C sol-gel material can be very different of those in α-Al{sub 2}O{sub 3}:C single crystal. (author)

Thermoluminescence of irradiated foods

International Nuclear Information System (INIS)

Wagner, U.; Helle, N.; Boegl, K.W.; Schreiber, G.A.

1993-01-01

This report describes developments and applications of the thermoluminescence (TL) analysis of mineral contaminants in foods. Procedures are presented to obtain minerals from most different products such as pepper, mangos, shrimps and mussels. The effect of light exposure during the storage of foods on the TL intensity of minerals is examined and corresponding conclusions for routine control are drawn. It is also shown that the normalization of TL intensities - the essential step to identify irradiated samples - can not only be achieved by γ, X or β rays but also by UV radiation. The results allow the conclusion that a clear identification of any food which has been irradiated with more than 1 kGy is possible if enough minerals can be isolated. (orig.)

Custom synthesized diamond crystals as state of the art radiation detectors

International Nuclear Information System (INIS)

Keddy, R.J.; Nam, T.L.; Fallon, P.J.

1990-01-01

The fact that as a radiation detector, diamond is a stable, non-toxic and tissue equivalent (Z=6) material, makes it an ideal candidate for in vivo radiation dosimetry or the dosimetry of general radiation fields in environmental monitoring. Natural diamond crystals have the disadvantage, however, that no two crystals can be guaranteed to have the same response characteristics. This disadvantage can be overcome by synthesizing the crystals under controlled conditions and by using very selective chemistry. Such synthetic diamonds can be used as thermoluminescence dosimeters (TLDs) where they exhibit characteristics comparable to presently available commercial TLDs or they can be used as ionization chambers to produce either ionization currents or pulses where the small physical size of the diamond (1 mm 3 ) and possibilities of digital circuitry makes miniaturization an extremely attractive possibility. It has also been found that they can perform as scintillation detectors. This contribution describes aspects of the performance characteristics of such diamonds in all three modes. 24 refs., 14 figs

Thermoluminescent dosemeters characterization for patient dosimetry in diagnostic radiology preliminary results

International Nuclear Information System (INIS)

Castro, William J.; Squair, Peterson L.; Gonzaga, Natalia B.; Nogueira, Maria S.; Silva, Teogenes A. da

2009-01-01

The determination of the metrological characteristics of thermoluminescent (TL) dosimeters plays an important role in dosimetry of patients submitted to x-ray examinations for diagnostic purpose. Entrance surface doses can be measured with TL dosimeters to verify the compliance with the diagnostic reference levels. Organ doses can be estimated through TL measurements in an anthropomorphic phantom which it allows the radiation risk assessment. In this work, LiF:Mg,Ti (TLD-100) rod and chip thermoluminescent dosimeters were characterized considering their use for patient dosimetry in computerized tomography and mammography. Preliminary results showed that TL dosimeters have a response reproducibility of 7.8% and 4.8% and homogeneity of 18.4% and 6.5% for rod and chip shapes, respectively. (author)

Persistent luminescence and thermoluminescence of UV/VIS -irradiated SrAl2O4: Eu2+, Dy3+ phosphor

International Nuclear Information System (INIS)

Pereyda-Pierre, C.; Meléndrez, R.; García, R.; Pedroza-Montero, M.; Barboza-Flores, M.

2011-01-01

The persistent luminescence and thermoluminescence properties of SrAl 2 O 4 : Eu 2+ , Dy 3+ phosphors excited with UV–VIS light in the 200–500 nm region were investigated. The thermoluminescence glow curve was found to be composed of peaks around 70, 125 and 245 °C. The persistent luminescence and thermoluminescence excitation spectra exhibited a broad band around 300–500 nm centered at 400 and 420 nm respectively. A linear behavior of the integrated thermoluminescence intensity and persistent luminescence versus irradiation time was found for the first 60 s. The charge detrapping from the 70 °C trapping levels was the major contributor to the observed persistent luminescence at room temperature. The SrAl 2 O 4 : Eu 2+ , Dy 3+ phosphors have suitable properties to be applied as storage and persistent luminescence UV–VIS irradiation dose phosphor. -- Highlights: ► SrAl 2 O 4 :Eu 2+ , Dy 3+ persistent luminescence and thermoluminescence was measured. ► The phosphor was irradiated with UV–VIS photons in the 200–500 nm wavelength range. ► SrAl 2 O 4 :Eu 2+ , Dy 3+ behaves adequately as persistent and storage UV–VIS dosimeter. ► The persistent luminescence dosimetry does not require heat or light stimulation.

Development of a nano structured system based on zirconia and Co nanoparticles for thermoluminescent applications: sensor of gamma and UV radiation

International Nuclear Information System (INIS)

Villa S, G.

2014-01-01

Powders of zirconium IV oxide as well as systems composed of zirconia nano crystals and cobalt nanoparticles (ZrO 2 :NPCo) with dimensions of nanometers were synthesized by the sol-gel method. Zirconia and ZrO 2 :NPCo systems have crystalline structure tetragonal or monoclinic is the heat treatment was to 500 and 1000 degrees Celsius respectively. The characterization of the synthesized materials consisted of a morphological and structural analysis, the information obtained was correlated to its thermoluminescent response induced by gamma and ultraviolet radiation. Thermoluminescent behavior was analyzed on different concentrations of cobalt nanoparticles incorporated during the synthesis process of the zirconium oxide. The monoclinic structure has the highest sensitivity thermoluminescent induced by ultraviolet and gamma radiation. Moreover, the thermoluminescence intensity decreased considerably in ZrO 2 :NPCo systems and was induced the growth of a glow peak at 280 degrees Celsius. In most of the materials analyzed the relation of the thermoluminescence intensity depending the time of irradiation with ultraviolet light showed the saturation of the traps in the material after 60 s of irradiation. Using gamma radiation is observed a behavior linear in the applied dose range between 0.25 Gy and 450 Gy. The growth of a glow peak at 280 degrees Celsius is the most important change in the thermoluminescence characteristics of zirconia. The ZrO 2 :NPCo systems can be used in the development of thermoluminescent dosimeters for detecting gamma radiation fields mainly. (Author)

Rede de Protagonismo Local para o Desenvolvimento Global

DEFF Research Database (Denmark)

Weber, Ángela; Hermann, Roberto Rivas

Este artigo pretende fazer uma reflexão sobre metodologia a ser desenvolvida e utilizada num projeto de desenvolvimento local, através das ações protagonizadas pela própria comunidade. Para isso parte de uma discussão sobre o conceito de desenvolvimento sustentável, e a seguir propõe a busca de f...

Dating of pre hispanic ceramics from the archaeological zone of Zoque by thermoluminescence method

International Nuclear Information System (INIS)

Valdes, J.V.; Gonzalez, P.R.; Mendoza, D.; Tenorio, D.; Terreros, E.; Ramirez, A.

2007-01-01

Full text: The dating of pre hispanic ceramics resides permitting us to located them in a certain period of the history; allows us to verify it origin. The thermoluminescence is a technique that permits us to estimate the absolute age of the archaeological samples. The present work is directed in determining the age by the method of thermoluminescence of archaeological samples of the grotto of Concubac, located in the Serrana Region of Tabasco. To determine the mineralogical composition of the samples, analysis of diffraction of X rays and Energy Dispersive X-ray Spectroscopy (EDS) have been conducted. The radiation emitted by the ground where the samples were buried and the contribution of the cosmic radiation was measured with thermoluminescent dosimeters of LiF:Mg,Cu,P+PTFE. The feasibility of dating of the studied samples is broadly disputed in function of the contents of minerals, as well as the procedure and management of the sample. (Author)

Intrinsic sensitivity calculation for a large number of LiF(Mg, Cu, P) detectors

International Nuclear Information System (INIS)

Argazzi, E.; Baldassarre, G.; De Maio, U.; Fantuzzi, E.; Monteventi, F.; Uleri, G.

1996-07-01

At the ENEA (Italian National Agency for New Technologies, Energy and the Environment) Personal Dosimetry Service it was decided to substitute the X and gamma dosimetry system based on BeO detectors in use since 10 years ago, with new dosimeters based on the new thermoluminescence material LiF(Mg,Cu,P). This report describes the procedures through which intrinsic sensitivity of a couple of TL detectors, which constitutes a card dosemeter, is determined. The intrinsic sensitivity archive allows to calculate the value of dose applying a specific correction factor for the systematic sensitivity, difference among the 60000 detectors used at the Service, therefore reducing the final uncertainty. The characterization of 60000 TL detectors has been possible only relying on a specific procedure and an informatic system. The irradiation and reading procedure allowed to take into account all the various uncertainty sources on TL readings and to carry out only one reading for almost all detectors. It could get through this aim using a reference group of dosimeters, characterized with an accuracy of 3%, to check each uncertainty parameter. Data acquisition and intrinsic sensitivity calculation have been carried out through an interactive procedure based on a personal computer connected with the reading instrument

Thermoluminescence dosimetry materials: properties and uses

International Nuclear Information System (INIS)

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

1995-01-01

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

Evaluation of glasses containing cadmium for high dose dosimetry by the thermoluminescence technique

International Nuclear Information System (INIS)

Carvalho, Gabriel Soares Marchiori de; Ferreira, Pamela Zati; Cunha, Diego Merigue da; Dantas, Noelio Oliveira; Silva, Anielle C.A.; Perini, Ana Paula; Neves, Lucio Pereira; Carrera, Betzabel Noemi Silva; Watanabe, Shigueo

2016-01-01

New glass matrices were evaluated for high dose dosimetry by the thermoluminescence technique. Their nominal composition are 20Li_2CO_3.10Al_2O_3.15CdO.55B_2O_3 and 20Li_2CO_3.10Al_2O_3.20CdO.50B_2O_3 (mol%). The glass matrices were irradiated with different doses: 50, 100, 200, 500, 700 and 900 Gy, and the thermoluminescence emission curves were obtained for each of these values. The results show a great potential of using these matrices in high dose dosimetry. (author)

Recent research into thermoluminescent dosimetry

Energy Technology Data Exchange (ETDEWEB)

Nakajima, T [National Inst. of Radiological Sciences, Chiba (Japan)

1979-04-01

The trend of basic research in thermoluminescent dosimetry (TLD), the results, and developing fields in which it can be applied are reported. This trend is outlined from the viewpoint fields of application, a new trend in TLD readers, the conditions of development of new photogenic substances, and research in the radiation characteristics of photogenic substances (radiosensitivity to particle rays and ultraviolet rays, dose rate dependence, temperature dependence at irradiation, and ..gamma.. ray energy dependence). Utilization of TLD in the medical field for measurement of environmental radiation and as a monitor for workers exposed to radiation is discussed. An international comparison of dose was necessary in order to prove its universal validity.

Thermoluminescence study of lithium fluorides

CERN Document Server

Abu-Alazm, S M

2003-01-01

The spectrum of the light emitted during thermoluminescence (TL) from irradiated lif sample with different doses of Xe, Kr and electrons have been studied. The results show a main peak for all samples irradiated and unirradiated at temperature about 200 degree C. Morcever when the reaches to the value 5x10 sup 1 1 ion/cm sup 2 a new two bands begin to appear in case of Xe and Kr ion irradiation. The TL spectra under Kr and Xe ion irradiation similar at the same dose. However, the spectra under electron irradiation were found to be rather different than under heavy ions irradiation.

Da revolução verde ao discurso do PRONAF: a representação do desenvolvimento nas políticas públicas de desenvolvimento rural no Brasil

Directory of Open Access Journals (Sweden)

Michell Leonard Duarte de Lima Tolentino

2016-12-01

Full Text Available Este trabalho procura refletir acerca das várias representações de desenvolvimento que embasam algumas das políticas públicas de desenvolvimento rural no Brasil, partindo das representações de desenvolvimento subjacentes à Revolução Verde e focando, posteriormente, no discurso do Programa Nacional de Fortalecimento da Agricultura Familiar (PRONAF. O trabalho se embasa em uma ampla pesquisa bibliográfica e documental. De início abordamos o discurso do desenvolvimento de forma crítica, para logo depois atentarmos para a maneira como este coloca o espaço rural. Para tanto utilizamos autores como Esteva (2000, Escobar (2000, Santos (1979 e Montenegro Gómez (2006. Posteriormente analisamos a Revolução Verde “brasileira” compreendendo o fordismo enquanto seu principal modelo de desenvolvimento. Em seguida, partimos para uma reflexão mais profunda sobre o PRONAF. O PRONAF assume fundamental importância nesse trabalho, pois o entendemos enquanto uma política de extrema relevância para se ler esse momento de inflexão das políticas públicas para o campo, de mudança nas representações sobre o espaço rural e o desenvolvimento rural brasileiro. Ao nos determos no PRONAF, discutimos a mudança de um modelo de desenvolvimento fordista para um modelo de desenvolvimento flexível.

PROPOSTA TEÓRICO-CONCEITUAL DE DESENVOLVIMENTO EM ARRANJOS PRODUTIVOS LOCAIS

Directory of Open Access Journals (Sweden)

Adriana Valélia Saraceni

2013-04-01

Full Text Available O objetivo central deste trabalho foi evidenciar algumas ferramentas para o desenvolvimento da inovação e verificar a relação com a configuração do desenvolvimento em Arranjos Produtivos Locais (APLs. Esta pesquisa pode ser considerada como exploratória e descritiva, pois envolve levantamento bibliográfico e análise de exemplos que estimulem a compreensão. Estudos sobre ferramentas de inovação tecnológica e referencias do desenvolvimento de ecossistemas industriais, foram utilizados buscando demonstrar uma proposta teórico-conceitual de integração das ferramentas. Por meio do resultado obtido com a aplicação da metodologia e do referencial teórico, verificou-se que aplicação das ferramentas de inovação tecnológica e a operacionalização com a implantação de métodos e ações cooperadas, tende a fortalecer o desempenho do processo de inovação do arranjo produtivo. A aplicação do conceito de ecologia industrial no desenvolvimento ambientalmente sustentável do aglomerado tende a fortalecer não só o desenvolvimento do APL, como também o desenvolvimento econômico e regional.

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Radiation dosimetry for microbial experiments in the International Space Station using different etched track and luminescent detectors

International Nuclear Information System (INIS)

Goossens, O.; Vanhavere, F.; Leys, N.; De Boever, P.; O'Sullivan, D.; Zhou, D.; Spurny, F.; Yukihara, E. G.; Gaza, R.; McKeever, S. W. S.

2006-01-01

The laboratory of Microbiology at SCK.CEN, in collaboration with different universities, participates in several ESA programmes with bacterial experiments that are carried out in the International Space Station (ISS). The main objective of these programmes is to study the effects of space flight conditions such as microgravity and cosmic radiation on the general behaviour of model bacteria. To measure the radiation doses received by the bacteria, different detectors accompanied the microbiological experiments. The results obtained during two space flight missions are discussed. This dosimetry experiment was a collaboration between different institutes so that the doses could be estimated by different techniques. For measurement of the high linear energy transfer (LET) doses (>10 keV μm -1 ), two types of etched track detectors were used. The low LET part of the spectrum was measured by three types of thermoluminescent detectors ( 7 LiF:Mg,Ti; 7 LiF:Mg,Cu,P; Al 2 O 3 :C) and by the optically stimulated luminescence technique using Al 2 O 3 :C detectors. (authors)

Thermoluminescence detected in Magicicada sp. exoskeletons

International Nuclear Information System (INIS)

Fields, D.E.; Randall, R.B.; Bauman, C.E. III

1979-01-01

Thermoluminescent emission from the irradiated exoskeletons of cicada have been observed. At a heating rate of approximately 60 0 C/min. the peak light emission temperature was 183 +- 3 0 C. This effect corresponds to charge-carrier trap parameters of Esub(a) = 0.82 +- 0.04 eV and w 0 = 10sup(9.1 +- 0.5) sec -1 . Response to filtered γ radiation of 50-kV peak energy was on the order of 3.2 x 10 6 photons/R/g. Insect exoskeletons are thus potentially useful as dosimeters. (author)

Thermoluminescent properties of ZnS:Mn nanocrystalline powders

International Nuclear Information System (INIS)

Ortiz-Hernández, Arturo Agustín; Méndez García, Víctor Hugo; Pérez Arrieta, María Leticia; Ortega Sígala, José Juan

2015-01-01

Thermoluminescent ZnS nanocrystals doped with Mn 2+ ions were synthesized by chemical co-precipitation method. From X-ray diffraction studies it was observed that the synthesized nanoparticles have cubic zinc blende structure with average sizes of about 40–50 nm. Morphology was analyzed by TEM. Photoluminescence studies showed two transitions, one of them close to 396 nm and other close to 598 nm, which is enhanced with increasing dopant concentration, this behavior was also observed in the cathodoluminescence spectrum. The thermoluminescence gamma dose-response has linear behavior over dose range 5–100 mGy, the glow curve structure shows two glow peaks at 436 K and at 518 K that were taken into account to calculate the kinetic parameters using the Computerized Glow Curve Deconvolution procedure. - Highlights: • Nanocrystals in powder of ZnS:Mn were synthesized using the co-precipitation method. • The integrated TL spectra has a linear behavior on the dose range 5–100 mGy of γ-radiation. • The kinetic parameters were obtained by the CGCD procedure. • Results support the possible use of nanocrystalline ZnS:Mn as a new γ-dose nanoTLD

Quality control of dosimetric systems using thermoluminescent crystals

International Nuclear Information System (INIS)

Mahecha, L.; Plazas, M. C.; Machado, M.; Perea, M. D.

2006-01-01

To achieve an optimal tumoral control to prostate cancer in early and locally advanced stages, it is necessary to increase the dose with a low mobility probability at the vesicle an rectal level. This is achieved through conformal radiotherapy. The Instituto Nacional de Cancerologia uses this technique, but two questions arise from the medical-physicists and medical radio-oncologist: In accordance with clinical protocols, the conformal radiotherapy delivers a low dose to the adjacent healthy tissues. What experimental method exists that can prove with certainly the veracity of this affirmation?. And, Do the dosimetric simulation system calculate suitable the dose for each tissues?. Through thermoluminescent dosimetry and the use of a physical simulator,we measured the absorbed dose at the target volume and the adjacent tissues using conformal and conventional radiotherapy. We proved that organs such as the rectum and bladder, receiver a minor dose in conformal radiotherapy, hence reducing their mobility probability. In addition, the readings from the thermoluminescent dosimeters and the doses calculated by the ECLIPSE dosimetric system were compared, concluding that the patient's prescribed dose is effectively delivered as recommended by the quality control program in radiotherapy. (Author)

Thermoluminescence of double fluorides doped with rare earths

International Nuclear Information System (INIS)

Azorin N, J.; Sanchez R, A.; Khaidukov, N.M.

2004-01-01

In this work the thermoluminescent characteristics of double fluorides K 2 YF 5 , K 2 GdF 5 and K 2 LuF 5 doped are presented with Tb 3+ , studied in the interval of temperature from 30 to 400 C. The materials that presented better answer to the irradiation with particles beta and with ultraviolet light they were the K 2 YF 5 : Tb (1% at. Tb 3+ ) and the K 2 LuF 5 : Tb (1% at. Tb 3+ ); while the K 2 YF 5 : Tb to high concentrations (10% and 20% at. Tb 3+ ) and the K 2 LuF 5 : Tb (1% at. Tb 3+ ) and the K 2 LuF 5 : Tb (1% at. Tb 3+ ) they presented an acceptable answer in front of the gamma radiation. The intensity of the Tl answer induced in these materials is a decisive factor to continue studying its dosimetric characteristics, what allows to consider them as the base for the development of potential materials to use them in the dosimetry of beta particles, of the UV light of the gamma radiation using the thermoluminescence method. (Author)

Thermo-luminescent dosimetry

Energy Technology Data Exchange (ETDEWEB)

Reither, M; Schorn, B; Schneider, E

1981-01-01

The development of paediatric radiology which began in the late 195O's has been characterised by the need to limit the dose of ionising radiation to which the child is subjected. The aim has been to keep radiation exposure as low as possible by the introduction of suitable techniques and by the development of new methods. It is therefore surprising that studies in dosimetry in the paediaytric age range have only been carried out in recent years. One reason for this may have been the fact that a suitable technique of measurement was not available at the time. The introduction of solid state dosimetry based on thermo-luminescence, first into radiotherapy (1968) and subsequently into radiodiagnosis, has made it possible to abandon the previously widely used ionisation chamber. The purpose of the present paper is to indicate the suitability of this form of dose measurement for paediatric radiological purposes and to stimulate its application in this field.

Thermoluminescence induced by X-rays in silica materials with metallic impurities

International Nuclear Information System (INIS)

Mendoza A, D.; Gonzalez M, P.; Espinosa P, M.; Salas, P.; Castano, V.M.

1999-01-01

Diverse materials of silica with Fe, Cu, Mg, and Mn impurities were synthesized by the sol-gel method, using tetraethyl orthosilicate as precursor. The materials obtained were subjected to thermal treatment at 500, 700 and 1000 Centigrade also they were irradiated with X-ray generated by a X-ray diffractometer which is installed in the ININ. The thermoluminescent signal was analysed and correlated with the type of impurities that are present in the material and with the grade of crystallinity produced by the thermal treatment in them. In according to the results obtained these materials show a thermoluminescent signal which is influenced by the crystallinity grade. It was analysed the behavior of the response for different doses, with the purpose of utilizing them to quantify very intense fields of radiation. (Author)

Applicability of thermoluminescent dosimeters in X-ray organ dose determination and in the dosimetry of systemic and boron neutron capture radiotherapy

International Nuclear Information System (INIS)

Aschan, C.

1999-01-01

The main detectors used for clinical dosimetry are ionisation chambers and semiconductors. Thermoluminescent (TL) dosimeters are also of interest because of their following advantages: (i) wide useful dose range, (ii) small physical size, (iii) no need for high voltage or cables, i.e. stand alone character, and (iv) tissue equivalence (LiF) for most radiation types. TL detectors can particularly be used for the absorbed dose measurements performed with the aim to investigate cases where dose prediction is difficult and not as part of a routine verification procedure. In this thesis, the applicability of TL detectors was studied in different clinical applications. Particularly, the major phenomena (e.g. energy dependence, sensitivity to high LET radiation, reproducibility) affecting on the precision and accuracy of TL detectors in the dose estimations were considered in this work. In organ dose determinations of diagnostic X-ray examinations, the TL detectors were found to be accurate within 5% (1 S.D.). For in viva studies using internal irradiation source, i.e. for systemic radiation therapy, a method for determining the absorbed doses to organs was introduced. The TL method developed was found to be able to estimate the absorbed doses to those critical organs near the body surface within 50%. In the mixed neutron-gamma field of boron neutron capture therapy (BNCT), TL detectors were used for gamma dose and neutron fluence measurements. They were found able to measure the neutron dose component with the accuracy of 16%, and therefore to be a useful addition to the activation foils in BNCT neutron dosimetry. The absorbed gamma doses can be measured with TL detectors within 20% in the mixed neutron-gamma field, which enables in viva measurements at BNCT beams with approximately the same accuracy. In this study, the uncertainties of TL dosimeters were found to be high but not essentially greater than those in other measurement techniques used for clinical dosimetry

Thermoluminescence dating

International Nuclear Information System (INIS)

Price, D.M.

1999-01-01

Thermoluminescence (TL) dating of sediments depends upon the acquisition and long term stable storage of TL energy by crystalline minerals contained within a sedimentary unit. This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Prior to the final depositional episode it is necessary that any previously acquired TL is removed by exposure to sunlight. After burial the TL begins to build up again at a rate dependent upon the radiation flux delivered by long-lived isotopes of uranium, thorium and potassium. The presence of rubidium and cosmic radiation generally play a lesser but contributory roll, and the total radiation dose delivered to the TL phosphor is modified by the presence of water. The period since deposition is therefore measured by determining the total amount of stored TL energy, the palaeodose (P), and the rate at which this energy is acquired, the annual radiation dose (ARD). TL dating may be applied to eolian, fluvial, coastal and in some cases, marine sediments. the technique is also successfully applied to volcanic materials and to a certain extent to archeological specimens

Thermoluminescent response of Y2O3:Ce,Eu irradiated with X-rays

International Nuclear Information System (INIS)

Sanchez J, F. del R.; Sosa A, M. A.

2017-10-01

The thermoluminescent response of various materials has been studied when irradiated with X-rays, and the parameters that characterize the order of the kinetics of the material, depth of traps and frequency have been determined. The objective of this project was to characterize the thermoluminescent response of dosimeters based on yttrium oxide (Y 2 O 3 ) irradiated with X-rays. To do this, the thermoluminescent response of the Y 2 O 3 :Ce,Eu dosimeter was measured and exposed to an X-ray radiation field; five levels of radiation were used: in the first, a potential of 53.5 kv was used and a working load of 5.6 m As, in the second: 70.0 kv, 12.5 m As; in the third: 81.0 kv, 20.0 m As; in the fourth: 109 kv, 32 m As, in the fifth: 121 kv, 80.0 m As, applying an exposure range between 17.7 and 40 R. The irradiation was performed exposing the sample at 104 cm from the focus of the X-ray tube. To obtain the readings of the thermoluminescent response, a Harshaw TLD 3500 reader was used. The data captured by the reader was processed using the WinREMS software. The deletion protocol was as follows: the dosimeters already read were placed, one hour in the Terlab MA12D muffle at a temperature of (400 ± 1) degrees centigrade, the dosimeters were removed and left at room temperature of 20 degrees centigrade for 20 minutes. Then they were placed in the Binder high temperature oven ED23 at 100 ± 1 centigrade degrees for 2 hours. The brightness curves were de convolved using the WebPlotDigitizer v 3.8 software and the individual peaks of the brightness curves were obtained. We found that: the synthesized materials presented a good thermoluminescent response when irradiated with X-rays. However, only one of the dosimeters, of Yttrium oxide doped with 0.5% Cerium, showed a relatively linear response in the applied dose range. The analysis made to the brightness curve of the Yttrium oxide doped with Cerium at 0.5%, applying the method of the three points for the parameters

An evaluation of the Panasonic model UD513AC-1 Thermoluminescence Dosimetry system

International Nuclear Information System (INIS)

Durrer, R.E. Jr.

1991-12-01

An evaluation of the Panasonic UD513AC-1 Thermoluminescence Dosimetry system was performed to determine the system's capabilities as a general purpose thermoluminescence dosimeter measuring device. The tests that were performed included a critique of the user's manual, delimitation of the operating parameters, the quality of construction, and an evaluation of the features that were unique to this system. The UD513AC-1 was found to be an adequate measuring device for most dosimetric applications. It was not well suited for experimental work with thermoluminescence materials due to a low sensitivity displayed by the photomultiplier tube to commonly used materials. The system was well constructed and did not suffer hardware failure during this research. Major attributes of the UD513AC-1 were automatic data storage, highly reproducible heating ramps, an excellent infrared light filter and a unique feature to a single phosphor unit, a dose determination function. Negative aspects of the system included a limited data manipulation capability within the controlling program, a poorly written user's manual, inadequate sensitivity on the part of the photomultiplier tube, and insufficient capability to adjust the hot N 2 gas flow to desired levels

Type test of the Rados MTS-N thermoluminescent dosimetry system for individual monitoring of whole body photons in HP (10)

International Nuclear Information System (INIS)

Ferreira, M.S.; Silva, E.R. da; Maurício, C.L.P.

2017-01-01

The Institute of Radioprotection and Dosimetry (IRD/CNEN-RJ), uses an automatic thermoluminescent dosimetry (TL) system for evaluation of whole body for photons with individual monitors RADOS MTS-N, with TLF detector of LiF: Mg, Ti. The objective of this work was to characterize this system for the evaluation of H P (10) operating magnitude. The measuring range is 0.2 mSv to 2 Sv, for photon energies from 20 keV to 1250 keV. Performance tests were done for the following characteristics: homogeneity of the monitors, system reproducibility, linearity, temperature and humidity effect, energy and angular dependence and fading. The acceptance requirements used to test system performance have been drawn from national and international documents. The results obtained prove that the system can be used to measure the occupational dose of photons in H P (10)

Evaluation of glasses containing cadmium for high dose dosimetry by the thermoluminescence technique

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Gabriel Soares Marchiori de; Ferreira, Pamela Zati; Cunha, Diego Merigue da; Dantas, Noelio Oliveira; Silva, Anielle C.A.; Perini, Ana Paula; Neves, Lucio Pereira, E-mail: lucio.neves@ufu.br [Universidade Federal de Uberlandia (INFIS/UFU), MG (Brazil). Instituto de Fisica; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Carrera, Betzabel Noemi Silva; Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), SP (Brazil). Instituto de Fisica

2016-07-01

New glass matrices were evaluated for high dose dosimetry by the thermoluminescence technique. Their nominal composition are 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.15CdO.55B{sub 2}O{sub 3} and 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.20CdO.50B{sub 2}O{sub 3} (mol%). The glass matrices were irradiated with different doses: 50, 100, 200, 500, 700 and 900 Gy, and the thermoluminescence emission curves were obtained for each of these values. The results show a great potential of using these matrices in high dose dosimetry. (author)

Study of a new glass matrix by thermoluminescent technique for high-dose dosimetry

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Pamela Z.; Carvalho, Gabriel S. Marchiori de; Cunha, Diego M. da; Dantas, Noelio O.; Silva, Anielle C.A.; Neves, Lucio P.; Perini, Ana P., E-mail: anapaula.perini@ufu.br [Universidade Federal de Uberlandia (UFU), MG (Brazil). Instituto de Fisica; Linda, V.E. Caldas [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carrera, Betzabel N.S.; Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica

2016-07-01

The thermoluminescence technique is widely used for both personal and for high-dose dosimetry. In this work, the thermoluminescence technique was utilized to study a new glass matrix, with nominal composition of 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.30BaO.40B{sub 2}O{sub 3} (mol%), irradiated with different doses in a {sup 60}Co source. The glow curves and the dose-response curve were obtained for radiation doses of 10, 50, 100, 200 e 700 Gy. The results showed that this new glass matrix has potential use in high-dose dosimetry. (author)

Ultraviolet radiation monitoring in makkah city, Saudi Arabia, using thermoluminescence material CaF2:Tm

International Nuclear Information System (INIS)

Al-Ghorabie, F.H.; Natto, S.S.; AL-Lehyani, S.A.

2005-01-01

The aim of the present study is to explore the possibility of using Ca F2:Tm thermoluminescence material for measuring and monitoring of solar UV R in Makkah City, Saudi Arabia. Several laboratory experiments, prior to the field measurements, were performed included study of the effects of ultraviolet wavelengths on the response of the phosphor, study of the effect of increasing ultraviolet radiation dose on the intensity of thermoluminescence and study the effect of time factor on the thermoluminescence fading of Ca F 2 :Tm. The phosphor was then exposed directly for one hour to sunlight radiation on a daily basis for 90 days in an open field inside Umm Al-Qura university campus. The field measurements were performed during the months of June, July and August 2003 at 1:00 p.m. The laboratory and field results of this study showed that Ca F 2 :Tm can be used as a suitable dosimeter for solar UV R

Methods for implementation of in vivo dosimetry (entrance dose) using thermoluminescent dosimeters during radiotherapy treatment with photon beam

International Nuclear Information System (INIS)

Barsanelli, Cristiane

2006-01-01

Selection, calibration procedure to convert TLD signal into absorbed dose and physical characteristics at the thermoluminescent dosimeters, as well as the determination of correction factors and the methodology to determine expected entrance dose, are described in this work. Practical aspects and the utility of entrance dose measures with thermoluminescent dosimeters were investigated, as well as the exactness and the reproducibility of the daily dose release. The entrance dose measures were performed in five patients with diagnosis of breast cancer treated with a 6 MV photon beam. The measured dose and the expected dose values agreed in ± 5%, due to excellent treatment equipment stability, to automatic verification system and the good exactness in the daily treatment adjustment. Good precision can be achieved when the correction factors for each parameter of influence in the dosimeter response are carefully determined and applied to convert the thermoluminescent signal into absorbed dose. The study demonstrates the viability of thermoluminescent dosimeters use for in vivo dosimetry and its utility as part of a quality assurance program in a radiation therapy service. (author)

The thermoluminescent curve as parameter to compare archaeological ceramics; La curva termoluminiscente como parametro para comparar ceramica arqueologica

Energy Technology Data Exchange (ETDEWEB)

Dominguez R, I.R.; Ramirez C, G.A. [Centro INAH Estado de Mexico. Morelos Ote. 502, Col. San Sebastian, 50090 Toluca, Estado de Mexico (Mexico); Gonzalez M, P.R.; Mendoza A, D. [lNIN, Carr. Mexico-Toluca S/N, La Marquesa, 52750 Ocoyoacac, Estado de Mexico (Mexico); Martinez C, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, INAH, Mexico D.F. (Mexico)

2006-07-01

Most mineral materials, including the constituents of pottery, have the property of thermoluminescence (TL), where part of the energy from radioactive decay in the mineral is stored and later released as light upon strong heating. The intensity of emitted light as a function of temperature is the thermoluminescence glow curve. However, it is well-know the thermoluminescence glow curve form depends of several factors associates with the incident radiation and type of materials. Between the factors associated with the materials, it can be mentioned the quantity and type of crystalline phases, and quantity and type of impurities that they could be present in the material. That is to say, materials with different physicochemical characteristics will produce different thermoluminescence glow curve, although, they have been irradiated under the same conditions. In accordance with the above mentioned, it is possible to identified differences between pre hispanic ceramic belonging to a same site and other sites. In this work a discussion about advantages and disadvantages is presented. Some specific examples in ceramic artifacts belonging to the Matlatzinca and Teotihuacan cultures are included. (Author)

Investigations on thermoluminescent dosimetry (TLD) with doped alumina ceramics

International Nuclear Information System (INIS)

Janas, R.; Huebner, K.

1976-01-01

Alumina ceramics doped and burned under various conditions have been investigated with regard to their suitability for thermoluminescent dosimetry. The production of ceramics is described. The properties essential for dosimetric purposes, such as glow curve, energy dose characteristics, fading, recoverability, lower detection limit and energy dependence, are indicated. The advantages and disadvantages of alumina ceramics are compared. (author)

Thermically stimulated exoelectronic emissions and thermoluminescence of MgO

International Nuclear Information System (INIS)

Chubaci, J.F.D.

1987-01-01

In this work, studies were performed on the following topics: i) thermically stimulated exoelectronic emission (TSEE) in pure MgO single crystals ion implanted, submitted to thermal treatment with fast on slow cooling and water adsorption; ii) ultraviolet light effect on TSEE; iii) thermoluminescent emission; iv) crystallization of FeCoB amorphous alloys. (A.C.A.S.) [pt

Development of a highly sensitive lithium fluoride thermoluminescence dosimeter

International Nuclear Information System (INIS)

Moraes da Silva, Teresinha de; Campos, Leticia Lucente

1995-01-01

In recent times, LiF: Mg, Cu, P thermoluminescent phosphor has been increasingly in use for radiation monitoring due its high sensitivity and ease of preparation. The Dosimetric Materials Production Laboratory of IPEN, (Nuclear Energy Institute) has developed a simple method to obtain high sensitivity LiF. The preparation method is described. (author). 4 refs., 1 fig., 1 tab

On the phototransferred thermoluminescence in MgB4O7:Dy

International Nuclear Information System (INIS)

Richmond, R.G.

1987-01-01

On exposure to ionizing radiations, the normal traps in MgB 4 0 7 :Dy can be emptied by the readout process only or by annealing at suitable temperatures, leaving the deep traps still intact. Subsequently, it is possible to repopulate the dosimetric peak by illuminating with u.v. light. Charge carriers released from the traps during the second readout give rise to a thermoluminescent output proportional to the ionizing radiation exposure and the u.v. radiant energy. This is called phototransferred thermoluminescence (PTTL). The PTTL method can be utilized for the reassessment of the initial γ-ray exposure. This paper presents the measurements of the intrinsic response of the commercially available MgB 4 0 7 :Dy to u.v. radiation, with a demonstration of its use for γ-ray dose re-estimation using the PTTL technique. (author)

Authenticity test in ceramics and archaeological figures by thermoluminescence; Prueba de Autenticidad en ceramicas y figuras arqueologicas por termoluminiscencia

Energy Technology Data Exchange (ETDEWEB)

Ramirez L, A.; Schaaf, P. [Laboratorio de Termoluminiscencia, Instituto de Geofisica-UNAM (Mexico); Filloy, L. [Museo Nacional de Antropologia e Historia, Ciudad de Mexico (Mexico)

1999-07-01

At present exists quite a lot of false archaeological pieces which provokes doubts about the legitimacy of the pieces. In this work it is presented the Authenticity test by Thermoluminescence realized at the urn of the goddess 13 serpent of the zapotec culture of Oaxaca which is exposed in Mexico City. The original piece contains crystalline structures which present hardly the thermoluminescence phenomena by the presence of {sup 238} U, {sup 232} Th, and {sup 40} K getting with this the form and intensity of the natural thermoluminescence curve of an archaeological piece which shows a Tl peak and allows to know so if it was made recently or not. (Author)

Thermoluminescence dosimetry applied to quality assurance in radiotherapy, brachytherapy and radiodiagnostic

Energy Technology Data Exchange (ETDEWEB)

Marinello, G [Centre Hospitalo-Universitaire, Creteil (France). Dept. Inter-Hospitalier de Cancerologie

1996-08-01

Thermoluminescence (TL) dosimetry is very interesting for in vivo measurements because TL detectors have the advantages of being very sensitive under a very small volume and do not meet to be connected to an electrometer with an unwieldy cable. The principle of the method being briefly recalled, criteria of choice of a TL material according to the applications to be performed are given. It is shown that to be used for in vivo measurements, TL material should have the same response at room and patient temperatures and be equivalent to soft tissue, lungs or bones for the energy ranges encountered in practice. Theoretical data are provided in order to facilitate the user`s choice. The different heating processes (linear or isothermal heating kinetics, hot gas, etc.) and light detection systems of TL readers are also presented. TL manual and automatic readers commercially available in 1994, and the emission temperature and wavelength the dosimetric peaks of usual TL materials are presented in two tables, respectively. Then the principal properties of TL dosimeters to be used for in vivo measurements and their practical consequences are summarized: signal stability after irradiation, intrinsic precision, sensitivity, response with dose, dose-rate, mass and energy. At last some examples of applications as different as total body and skin irradiations, brachytherapy, diagnostic radiology and quality assurance purposes are given. (author). 35 refs, 6 figs, 4 tabs.

Thermoluminescence of novel MgO–CeO_2 obtained by a glycine-based solution combustion method

International Nuclear Information System (INIS)

Barrón, Victor Ramón Orante; Ochoa, Flor María Escobar; Vázquez, Catalina Cruz; Bernal, Rodolfo

2016-01-01

Thermoluminescence dosimetry properties of novel MgO–CeO_2 obtained by solution combustion synthesis in a glycine-nitrate process, are presented for the very first time. X-ray diffraction indicates the presence of cubic MgO and cerianite (CeO_2) for the annealed powder samples. Dosimetry features such as linear behaviour of the dose response without saturation in the dose interval studied, as well as asymptotic behaviour of the thermoluminescent signal fading place MgO–CeO_2 phosphor as a promising material for low-dose radiation dosimetry applications. - Highlights: • Thermoluminescence (TL) dosimetry properties of novel MgO–CeO_2 are presented. • TL glow curves display stable and dosimetric components. • Dose response showed a linear trend in the dose interval studied. • TL fading decay curve showed an asymptotic behaviour. • MgO–CeO_2 is suitable for personal, environmental and medical dosimetry.

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

Thermoluminescence as a criterium in the acquisition of ceramic art objects

International Nuclear Information System (INIS)

Erlach, R.; Pichler, B.

1985-01-01

Thermoluminescence is a measure for the external archeological dose received and can be used for age estimation. Examples are given of Egyptian objects where the age is known independently and thereby the accuracy of the method can be evaluated. (G.Q.)

Utilization of thermoluminescent dosemeters in radiation field studies for different materials

International Nuclear Information System (INIS)

Carron, W.; Guilardi Neto, T.

1987-01-01

The dose conversion factor of lithium fluoride thermoluminescent for the follows materials: water, wood and soil, the dose curve surveying in function of depth and the regression equations that better adapt to the dose curves were calculated. (C.G.C.) [pt

Thermoluminescent kinetic parameters of the perovskite, KMgF3, activated with lanthanum

International Nuclear Information System (INIS)

Sepulveda M, F.; Azorin N, J.; Rivera M, T.; Furetta, C.; Sanipoli, C.

2004-01-01

The thermoluminescent curves induced by the beta radiation in the perovskite KMgF 3 were investigated activated with lanthanum. The classic methods were used to determine the kinetic parameters (the kinetic order b, the activation energy E and the frequency of escape intent s) associated with the peaks of the thermoluminescent curve (Tl) in the KMgF 3 activated with lanthanum after the irradiation with beta rays. The method is based on the position of the thermoluminescent peaks, obtained of the temperature change of the peak in the maximum emission caused by the change in the heating rapidity to which the samples were measured. In this work, the samples in form of pellets were re cooked previously at 400 C during one hour before irradiating them with beta particles. The Tl measures were made with a Tl reader system using three different heating rapidities and storing the glow curves. To calculate the depth of the E traps and the frequency factor s, the parameters of the glow curve were determined experimentally of the shame of the glow curve by means of the mensuration of the shame of the maximum temperature of the peak, T M like a function of the heating rapidity. The results indicate that the values of the kinetic parameters are very near among if when they are obtained indistinctly of anyone of the different methods. (Author)

O conceito histórico de desenvolvimento econômico

OpenAIRE

Pereira, Luiz C. Bresser

2006-01-01

Uma Análise do Conceito de Desenvolvimento Econômico. o Crescimento Econômico, ou Desenvolvimento Econômico, é Visto como um Fenômeno Histórico como Resultado da Revolução Capitalista, E, Consequentemente, da Revolução Comercial, da Industrial E, no Meio Delas, da Revolução Nacional. Assim, é Necessário um Conceito Histórico de Crescimento Econômico, e não um Conceito Normativo. Visto sob este Aspecto, o Desenvolvimento Econômico é Intrinsecamente Relacionado ao Surgimento do Estado-Nação M...

Determinantes do desenvolvimento do setor agropecuário nos municípios

Directory of Open Access Journals (Sweden)

Caio César de Medeiros Costa

2013-06-01

Full Text Available Dada a importância do setor agropecuário para a economia brasileira, é fundamental conhecer os fatores determinantes do desenvolvimento agropecuário em seus municípios. Sob a luz de referencial teórico que aborda questões relacionadas aos fatores determinantes do desenvolvimento agropecuário e do desenvolvimento econômico local, neste estudo fez-se uso das metodologias de análise multivariada conhecidas como análise fatorial e análise de cluster. Utilizou-se o estado de Minas Gerais como recorte analítico. Foram selecionadas 22 variáveis para cada município, representando diferentes dimensões do desenvolvimento, visando verificar quais os fatores determinantes do desenvolvimento agropecuário. Após a análise fatorial, optou-se pela extração de seis fatores com raiz característica maior do que um e que respondem, em conjunto, por 62,25% da variância total dos dados: desenvolvimento econômico, investimento público, qualidade de vida, condições da atividade agropecuária, condições de meio ambiente e consumo, e condições de financiamento. Pela análise de cluster, foram criados cinco grupos, de acordo com o desempenho dos membros nos fatores. Os resultados corroboram os apontamentos literários em quase sua totalidade e, além disso, destaca-se e discute-se a existência de um ciclo positivo gerado pelo incremento dos fatores determinantes do desenvolvimento agropecuário e pelas vantagens competitivas. Neste estudo, aponta-se a importância do investimento público na promoção do desenvolvimento, reforçando o proposto por trabalhos anteriores de que o Estado desempenha papel fundamental para garantir condições que propiciem o desenvolvimento do setor agropecuário. Outra constatação factível é a de que fatores isolados, tais como as boas condições da agricultura e do meio ambiente, não são capazes de propiciar desenvolvimento para o setor nos municípios mineiros.

Percentage depth dose evaluation in heterogeneous media using thermoluminescent dosimetry

Science.gov (United States)

da Rosa, L.A.R.; Campos, L.T.; Alves, V.G.L.; Batista, D.V.S.; Facure, A.

2010-01-01

The purpose of this study is to investigate the influence of lung heterogeneity inside a soft tissue phantom on percentage depth dose (PDD). PDD curves were obtained experimentally using LiF:Mg,Ti (TLD‐100) thermoluminescent detectors and applying Eclipse treatment planning system algorithms Batho, modified Batho (M‐Batho or BMod), equivalent TAR (E‐TAR or EQTAR), and anisotropic analytical algorithm (AAA) for a 15 MV photon beam and field sizes of 1×1,2×2,5×5, and 10×10cm2. Monte Carlo simulations were performed using the DOSRZnrc user code of EGSnrc. The experimental results agree with Monte Carlo simulations for all irradiation field sizes. Comparisons with Monte Carlo calculations show that the AAA algorithm provides the best simulations of PDD curves for all field sizes investigated. However, even this algorithm cannot accurately predict PDD values in the lung for field sizes of 1×1 and 2×2cm2. An overdosage in the lung of about 40% and 20% is calculated by the AAA algorithm close to the interface soft tissue/lung for 1×1 and 2×2cm2 field sizes, respectively. It was demonstrated that differences of 100% between Monte Carlo results and the algorithms Batho, modified Batho, and equivalent TAR responses may exist inside the lung region for the 1×1cm2 field. PACS number: 87.55.kd

Thermoluminescence glow curve of CaZrO3 phosphor doped with Eu3+

International Nuclear Information System (INIS)

Tiwari, Neha; Kuraria, R.K.; Kuraria, S.R.

2014-01-01

Behaviour displayed by thermoluminescence analysis of Eu 3+ doped CaZrO 3 phosphor prepared by combustion synthesis technique. The sample was synthesized by combustion method because it is less time taking method as well as low temperature synthesis. For the thermoluminescence study the prepared sample irradiated by UV lamp the wavelength is 254 nm. Every time 2 mg of sample used for TL record at fixed heating rate 5℃ s -1 , sample shows well resolved higher temperature peak at 273℃. The high temperature peak shows more stability and less fading in prepared phosphor which is suitable for TL dosimetry. Also the variation with UV dose (5 to 30 min) shows sublinear response with dose

Thermoluminescent dosimetry for LDEF experiment M0006

International Nuclear Information System (INIS)

Chang, J.Y.; Giangano, D.; Kantorcik, T.; Stauber, M.; Snead, L.

1992-01-01

Experiment M0006 on the Long Duration Exposure Facility had as its objective the investigation of space radiation effects on various electronic and optical components, as well as on seed germination. The Grumman Corporate Research Center provided the radiation dosimetric measurements for M0006, comprising the preparation of thermoluminescent dosimeters (TLD) and the subsequent measurement and analysis of flight exposed and control samples. In addition, various laboratory exposures of TLD's with gamma rays and protons were performed to obtain a better understanding of the flight exposures

Semiconductor scintillator detector for gamma radiation; Detector cintilador semicondutor para radiacao gama

Energy Technology Data Exchange (ETDEWEB)

Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S., E-mail: ftvdl@ufrgs.br, E-mail: borges@ufrgs.br, E-mail: jorge.zabadal@ufrgs.br [Universidade Federal do Rio Grande do Sul (GENUC/DEMEC/UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares. Departamento de Engenharia Mecanica

2015-07-01

Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

Deconvolution of the thermoluminescent emission curve. Second order kinetics

International Nuclear Information System (INIS)

Moreno y M, A.; Moreno B, A.

1999-01-01

In this work it is described the Randall and Wilkins second order kinetics in Microsoft Excel language, which allows its expression as the sum of Gaussian and the correction factors corresponding. These factors are obtained of the differences between the real thermoluminescent curve and the Gaussian proposed. The results obtained justify the Gaussian expression added to the correction factor. (Author)

The application of thermoluminescence dosimeters to studies of released activity distributions

International Nuclear Information System (INIS)

Ruden, B.I.

1969-06-01

In this report the theoretical conditions necessary for the study of the behaviour of released activity by the use of CaSO 4 : Mn thermoluminescence dosimeters are considered. A method is derived for calculating exposure distributions from drifting volume activity. The correlation between exposure distributions and concentration distributions is discussed. One of thirty experiments where Br 82 was released into water through a nozzle some metres above the bottom is described. The resulting exposure distribution was measured in a vertical plane at distances of 10, 50 and 200 metres by CaSO 4 : Mn thermoluminescence dosimeters. The measured exposures are described and discussed. The advantages and disadvantages of the technique are compared with other methods. The method using exposure measurements for the study of active release in water has given satisfactory results in practice. The measurements have been made at concentration levels which are considerably below that permissible for drinking water according to the recommendations by ICRPA special advantage with this method is that the measurements can be made simultaneously at a large number of places and that integration is possible over sufficiently long periods of time. An experiment is described where Ar 41 was released in free air at a height of one metre above ground and the resulting exposure distribution was measured in a vertical plane at 100 and 250 metres distance by CaSO 4 : Mn thermoluminescence dosimeters. Shielding problems in connection with the experiments have been small since the method permits the measurement of very small doses. An account is given of the possibility of using the beta emitting isotope Kr 85 instead of the gamma emitting Ar 41 for diffusion experiments in air. The results obtained from some experiments are presented and discussed. The thermoluminescent signal from the dosimeters are, at the same concentration and exposure time, 2.5 times greater for Kr 85 than for Ar 41. The Kr

Thermoluminescent dosimetry of ionizing radiations using ZrO2 prepared at low temperatures

International Nuclear Information System (INIS)

Rivera M, T.; Diaz G, J.A.I.; Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M.

2005-01-01

The thermoluminescent dosimetry (TLD) it is a versatile tool for an evaluation of dose of ionizing radiation. A great variety of ceramic materials and their different physical forms allow a determination of the ionizing radiation in a wide dose interval. In this work the results of studying those thermoluminescent characteristics (TL) of the zirconium oxide obtained by means of the sol-gel technique to low temperatures are presented. To these temperatures the material was obtained in its amorphous state (ZrO 2 -a). The structural characteristics of ZrO 2 -a they were obtained by means of X-ray diffraction. The TL characteristics studied were: TL curve, reproducibility of the TL signal and the fading of the information. The powders of ZrO 2 -a, previously irradiated with beta particles of 90 Sr/ 90 Y, they presented a thermoluminescent curve with two peaks at 150 and 260 C. The fading of the information of the one ZrO 2 -a it was of 20% during the first two hours starting from this time there was one lost of information of 5% to the finish of the 30 days. The reproducibility of the information was of ± 2.5% in standard deviation. (Author)

Modelling the optical bleaching of the thermoluminescence of K2YF5:Pr3+

International Nuclear Information System (INIS)

Marcazzó, J.; Santiago, M.; Khaidukov, N.; Caselli, E.

2012-01-01

Optical bleaching of the thermoluminescence (TL) curve of K 2 YF 5 :Pr 3+ has been observed after optically stimulated luminescence (OSL) readout of pre-irradiated crystals. The traps being responsible for the TL signal are not emptied completely by the optical stimulation. Furthermore, if the illumination time is increased a constant intensity level of the residual TL glow curve is eventually achieved. On the other hand, if the low temperature peak of the glow curve is thermally cleaned, no subsequent OSL is measured. This behavior has been successfully explained by assuming that part of the electrons in the trap being responsible for the low temperature glow peak of K 2 YF 5 :Pr 3+ recombine with holes via localized transitions during optical stimulation. During TL all trapped electrons recombine via delocalized transitions. Simulations have been carried out in order to demonstrate the feasibility of the model. - Highlights: ► The optical bleaching of the thermoluminescence of K2YF5:Pr 3+ has been studied. ► A model accounting for the optical bleaching has been put forward. ► Thermoluminescence occurs via delocalized transitions. ► Localized transitions occur during optical stimulation.

A família e a escola como contextos de desenvolvimento humano

Directory of Open Access Journals (Sweden)

Maria Auxiliadora Dessen

2007-04-01

Full Text Available Escola e família constituem dois contextos de desenvolvimento fundamentais para a trajetória de vida das pessoas. Neste artigo, são destacadas as contribuições destes contextos para a promoção do desenvolvimento humano, enfatizando suas implicações nos processos evolutivos. Questões sobre configurações, vínculos familiares e a importância da rede social de apoio para o desenvolvimento da família são discutidas. Focalizam-se as funções da escola, considerando sua influência nas pessoas em desenvolvimento. Apontam-se algumas considerações sobre a necessidade de compreender as inter-relações entre escola e família, visando facilitar a aprendizagem e desenvolvimento humano. A integração entre esses dois contextos é destacada como desafio para a prática profissional e pesquisa empírica.

Thermoluminescence of thin films deposited by laser ablation; Termoluminiscencia de peliculas delgadas depositadas por ablacion laser

Energy Technology Data Exchange (ETDEWEB)

Escobar A, L.; Camps, E.; Arrieta, A.; Romero, S.; Gonzalez, P.R.; Olea M, O.; Diaz E, R. [Depto. de Fisica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2003-07-01

Materials in thin film form have received great attention in the last few years mainly because of their singular properties, which may differ significantly from their bulk attributes making them attractive for a wide variety of applications. In particular, thermoluminescence (Tl) properties of thin films have been studied recently owing to their potential applications in detection for both ionizing and non ionizing radiation. The aim of the present work is to report the synthesis and characterization of C Nx, aluminum oxide and titanium oxide thin films. Thermoluminescence response of the obtained thin films was studied after subject thin films to UV radiation (254 nm) as well as to gamma radiation (Co-60). Thermoluminescence glow curves exhibited a peak centered at 150 C for CN{sub x} whereas for titanium oxide the glow curve shows a maximum peaking at 171 C. Characterization of the physical properties of the deposited materials is presented. (Author)

Valores e Desenvolvimento Humano

NARCIS (Netherlands)

F. Comim (Flavio); A. Macedo de Jesus (Anderson); R.C.B Oliveira (Raissa); A. Davison (Anna); S. Galeno (Sabrina); A.C.V. Ribeiro (Ana)

2010-01-01

markdownabstractA primeira parte desse Relatório de Desenvolvimento Humano do Brasil 2009/2010 começa com a descrição de um amplo processo de consulta aberta à sociedade, denominada Brasil Ponto a Ponto, para a escolha do tema do relatório. A Campanha Brasil Ponto a Ponto teve por objetivo

Thermoluminescence in medical dosimetry

International Nuclear Information System (INIS)

Rivera, T.

2011-10-01

The dosimetry by thermoluminescence (Tl) is applied in the entire world for the dosimetry of ionizing radiations specially to personal and medical dosimetry. This dosimetry method has been very interesting for measures in vivo because the Tl dosimeters have the advantage of being very sensitive in a very small volume and they are also equivalent to tissue and they do not need additional accessories (for example, cable, electrometer, etc.) The main characteristics of the diverse Tl materials to be used in the radiation measures and practical applications are: the Tl curve, the share homogeneity, the signal stability after the irradiation, precision and exactitude, the response in function with the dose and the energy influence. In this work a brief summary of the advances of the radiations dosimetry is presented by means of the thermally stimulated luminescence and its application to the dosimetry in radiotherapy. (Author)

Thermally stimulated conductivity and thermoluminescence from Al2O3 : C

DEFF Research Database (Denmark)

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

1999-01-01

Simultaneous measurements of thermoluminescence (TL) and thermally stimulated conductivity (TSC) are reported on single-crystal dosimetry-quality Al2O3:C following gamma irradiation at room temperature. Analysis of the data reveals a superposition of several first-order TL and TSC peaks caused...

Thermoluminescence dating of some Hungarian medieval churches

International Nuclear Information System (INIS)

Kasa, I.; Bajnoczy, G.

1984-01-01

Thermoluminescence dating of three Hungarian historic churches was performed using the quarz inclusion technique and sup(60)Co gamma irradiation. Quarz grains obtained from the bricks were irradiated and the radiation doses were measured by CaSOsub(4):Dy TL dosemeters. Glow curves of irradiated and non-irradiated samples were also measured. From the results it was concluded that the ages of two churches were 10 and 30 percent less, respectively, than the ages estimated earlier. The age of the third church proved to be correct. (R.P.)

Measurement of the dose by dispersed radiation in a lineal accelerator using thermoluminescent dosimeters of CaSO4:Dy

International Nuclear Information System (INIS)

Chavez C, N.; Torijano, E.; Azorin, J.; Herrera, A.

2014-08-01

The thermoluminescence (Tl) is based on the principle of the luminescent in a material when is heated below their incandescence temperature. Is a technique very used in dosimetry that is based on the property that have most of the crystalline materials regarding the storage of the energy that they absorb when are exposed to the ionizing radiations. When this material has been irradiated previously, the radioactive energy that contains is liberated in form of light. In general, the principles that govern the thermoluminescence are in essence the same of those responsible for all the luminescent processes and, this way, the thermoluminescence is one of the processes that are part of the luminescence phenomenon. For this work, the dispersed radiation was measured in the therapy area of the lineal accelerator of medical use type Elekta, using thermoluminescent dosimeters of CaSO 4 :Dy + Ptfe developed and elaborated in the Universidad Autonoma Metropolitana, Unidad Iztapalapa. With the dosimeters already characterized and calibrated, we proceeded to measure the dispersed radiation being a patient in treatment. The results showed values for the dispersed radiation the order of a third of the dose received by the patient on the treatment table at 30 cm of the direct beam and the order of a hundredth in the control area (4 m of the direct beam, approximately). The conclusion is that the thermoluminescent dosimeters of CaSO 4 : Dy + Ptfe are appropriate to measure dispersed radiation dose in radiotherapy. (author)

Preparando um ambiente de desenvolvimento para a plataforma android

Directory of Open Access Journals (Sweden)

Felipe Pires de Oliveira

2015-11-01

Full Text Available Este artigo descreve as etapas para a criação de um ambiente de desenvolvimento para a plataforma Android. O artigo foi dividido em quatro partes: Primeiro uma introdução sobre o assunto. Na segunda seção são mostrados os passos necessários para a configuração do ambiente de desenvolvimento. Na terceira seção, é demonstrado como criar uma aplicação para dispositivo Android que calculo Índice de Massa Corporal (IMC. A quarta seção apresenta as considerações finais. A solução abordada tem como base a IDE Eclipse e o SDK do Android, bem como o Kit de Desenvolvimento Java da Oracle (JDK.

Preparando um ambiente de desenvolvimento para a plataforma android

Directory of Open Access Journals (Sweden)

Felipe Pires de Oliveira

2015-12-01

Full Text Available Este artigo descreve as etapas para a criação de um ambiente de desenvolvimento para a plataforma Android. O artigo foi dividido em quatro partes: Primeiro uma introdução sobre o assunto. Na segunda seção são mostrados os passos necessários para a configuração do ambiente de desenvolvimento. Na terceira seção, é demonstrado como criar uma aplicação para dispositivo Android que calculo Índice de Massa Corporal (IMC. A quarta seção apresenta as considerações finais. A solução abordada tem como base a IDE Eclipse e o SDK do Android, bem como o Kit de Desenvolvimento Java da Oracle (JDK.

Amenidades ambientais e desenvolvimento rural

OpenAIRE

Dentinho, Tomaz; Rodrigues, Orlando

2007-01-01

Este texto sobre amenidades ambientais e desenvolvimento rural trata, fundamentalmente, da incerteza resultante da reacção das pessoas e das instituições face aos recursos naturais que exploram e quanto ao efeito das políticas que são implementadas.

Effect of Mineral Composition on Thermoluminescence Analysis of Irradiated Garlics

International Nuclear Information System (INIS)

Sookkasem, Atitaya; Wanwisa, Sudprasert; Vitittheeranon, Arag

2009-07-01

Full text: Thermoluminescence (TL) is one of the most popular techniques used for identification of irradiated foods such as spices, herbs and dried fruits in accordance with the Codex Standards. TL analysis is based on the determination of TL of adhering or contaminating minerals in foods. This research aimed to study the effect of mineral composition on the TL intensity. The composited minerals were extracted from 3 types of non-irradiated and irradiated garlic powders by sodium polytungstate solution. X-ray diffraction (XRD) spectroscopy was employed to investigate the type and amount of minerals present in garlic powders. TL of separated minerals were analysed using a Harshaw 4500 TL reader. The results showed that the mineral composition of garlic powders was mainly quartz of varying amounts depending on types of garlics. The TL intensity linearly increased with the amount of quartz present in the samples. It can be concluded that the amount of minerals affect the TL intensity which might influence the identification of irradiated tretment of garlics by thermoluminescence

PATRIMÔNIO CULTURAL ARQUEOLÓGICO: INSTRUMENTO DE DESENVOLVIMENTO TURÍSTICO

OpenAIRE

Rossano Bastos

2012-01-01

O presente trabalho trata das perspectivas de aproveitamento do Patrimônio Cultural Arqueológico como instrumento de desenvolvimento turístico.PALAVRAS-CHAVE: Arqueologia; Turismo;Desenvolvimento.ABSTRACT: This work considers some improvement perspectives ofthe archaeological cultural heritage as an instrument of tourism development.KEY-WORDS: Archaeology; Tourism; Development. 

Incompatibility of sensitisation and re-estimation of lithium fluoride thermoluminescent phosphor

International Nuclear Information System (INIS)

Bartlett, D.T.; Sandford, D.J.

1978-01-01

A technique of useful sensitisation of lithium fluoride thermoluminescent phosphor has been reported by Mayhugh and Fullerton, (USAEC Report COO-1105-209, 1974). This technique differs from that previously described (Cameron and Zimmerman, USAEC Report COO-1105-102, 1965) in that during the anneal at 300 degrees C which follows the high pre-dose, the phosphor is simultaneously exposed to 254 nm ultraviolet light. It is reported that this method removes interfering centres and hence reduces the lowest detectable dose. Sensitisation also has the advantages of improved tissue equivalence and increased range of linearity. However, a disadvantage of both techniques of sensitisation is that for sensitised phosphor, absorbed doses cannot be re-estimated by photo-transferred thermoluminescence. Results are compared for discs of lithium fluoride in PTFE, some of which were sensitised by each method, and some left unsensitised. It is concluded that for routine personal dosimetry the disadvantages of the loss of the facility to re-estimate absorbed dose outweighs the reported advantages of sensitisation. (author)

Thermoluminescence dosimetry: State-of-the-art and frontiers of future research

International Nuclear Information System (INIS)

Horowitz, Y.S.

2014-01-01

The state-of-the-art in the use of thermoluminescence for the measurement of energy imparted by ionizing radiation is discussed. Emphasis is on the advantages obtainable by the use of computerized glow curve analysis in (i) quality control, (ii) low dose environmental dosimetry, (iii) medical applications (especially precision) and microdosimetric applications, and (iv) mixed field ionization-density–dosimetry. Possible frontiers of future research are highlighted: (i) vector representation in glow curve analysis, (ii) combined OSL/TL measurements, (iii) detection of sub-ionization electrons, (iv) requirements for new TL materials and (v) theoretical subjects involving kinetic modeling invoking localized/delocalized recombination applied to dose response and track structure theory including creation of defects. - Highlights:: • State of the art in thermoluminescence dosimetry. • Benefits of computerized glow curve deconvolution. • Frontiers of future research:new materials, mixed-field dosimetry. • Localized/delocalized kinetic theory:ionization density dependence. • Kinetic theory:creation of defects:track structure theory

Proposal of a methodology for quality control in thermoluminescent dosimetry laboratory

International Nuclear Information System (INIS)

Feital, Joao Carlos da S.; Almeida, Claudio Domingues de; Bezerra, Marcos A.

2005-01-01

Taken into account that in thermoluminescence dosimetry adequate selection procedures as well as accurate TLD readings are necessary, this paper presents results of methodology that can be applied as part of quality control programs in thermoluminescence dosimetry laboratories. For the experiment, a set of 200 TLDs ( LiF 100 ) were used and 9 from which were selected, a standard source of Cs -137 , a PTW kiln, a TL 'Harshaw' reader - model 5500 operating under the 'Win Rem' software and a Sr 90 / Y 90 'Bicron' irradiator. In the proceeding the selected dosimeters were irradiated and read 28 times during 18 months, then by one of the standard deviation properties, values up to 14 % were found, for a confidence level of 95 %. The results found and the bibliographic data related to the responses (arbitrary reading) in the crystals used in TLDs, have shown that this methodology can be applied in quality control programs. (author)

Dose measurements in dental radiology using thermoluminescent dosimetry;Medicoes de dose em radiodiagnostico odontologico utilizando dosimetria termoluminescente

Energy Technology Data Exchange (ETDEWEB)

Chiara, Ana Claudia M. de; Costa, Alessandro M. [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras; Pardini, Luiz Carlos [Universidade de Sao Paulo (FORP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Odontologia

2009-07-01

The aim of this work was the implementation of a code of practice for dosimetry in dental radiology using the technique of thermoluminescent dosimetry. General principles for the use of thermoluminescent dosimeters were followed. The irradiations were performed using ten X-ray equipment for intra-oral radiography and an X-ray equipment for panoramic radiography. The incident air kerma was evaluated for five different exposure times used in clinical practice for intra-oral radiographs. Using a backscatter factor of 1.2, it was observed that approximately 40% of the entrance skin dose values found for intra-oral radiographs are above the diagnostic reference level recommended in national regulation. Different configurations of voltage and current were used representing the exposure as a child, woman and man for panoramic radiographs. The results obtained for the air kerma area product were respectively 53.3 +- 5.2 mGy.cm{sup 2}, 101.5 +- 9.5 mGy.cm{sup 2} and 116.8 +- 10.4 mGy.cm{sup 2}. The use of thermoluminescent dosimetry requires several procedures before a result is recorded. The use of dosimeters with ionization chambers or semiconductors provides a simple and robust method for routine measurements. However, the use of thermoluminescent dosimetry can be of great value to large-scale surveys to establish diagnostic reference levels. (author)

Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

Energy Technology Data Exchange (ETDEWEB)

Repetto, Guillermo, E-mail: grepkuh@upo.es [Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Seville (Spain); Zurita, Jorge L. [Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Seville (Spain); Roncel, Mercedes; Ortega, José M. [Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, 41092 Seville (Spain)

2015-01-15

Highlights: • There are very few toxicological applications of thermoluminescence. • It is a luminescence emission induced by heating the sample in the dark. • It is useful for study the photosystem II function and the level of lipid peroxidation. - Abstract: Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromobenzene and diethanolamine, the antioxidant propyl gallate, the semiconductor indium nitrate, the pesticide sodium monofluoroacetate and the antimalarial drug chloroquine. Electron transfer activity of the photosystem II significantly decreased after the exposure of Chlorella cells to all the six chemicals used. Lipid peroxidation was slightly decreased by the antioxidant propyl gallate, not changed by indium nitrate and very potently stimulated by diethanolamine, chloroquine, sodium monofluoroacetate and bromobenzene. For five of the chemicals studied (not bromobenzene) there is a very good correlation between the cytotoxic effects in Chlorella cells measured by the algal growth inhibition test, and the inhibition of photosystem II activity. The results suggest that one very important effect of these chemicals in Chlorella cells is the inhibition of photosynthetic metabolism by the blocking of photosystem II functionality. In the case of sodium monofluoroacetate, diethanolamine and chloroquine this inhibition seems to be related with the induction of high level of lipid peroxidation in cells that may alter the stability of photosystem II. The results obtained by both techniques supply information that can be used as a supplement to the growth inhibition test and allows a more complete assessment of the effects of

Thermoluminescence as a complementary technique for the toxicological evaluation of chemicals in photosynthetic organisms

International Nuclear Information System (INIS)

Repetto, Guillermo; Zurita, Jorge L.; Roncel, Mercedes; Ortega, José M.

2015-01-01

Highlights: • There are very few toxicological applications of thermoluminescence. • It is a luminescence emission induced by heating the sample in the dark. • It is useful for study the photosystem II function and the level of lipid peroxidation. - Abstract: Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromobenzene and diethanolamine, the antioxidant propyl gallate, the semiconductor indium nitrate, the pesticide sodium monofluoroacetate and the antimalarial drug chloroquine. Electron transfer activity of the photosystem II significantly decreased after the exposure of Chlorella cells to all the six chemicals used. Lipid peroxidation was slightly decreased by the antioxidant propyl gallate, not changed by indium nitrate and very potently stimulated by diethanolamine, chloroquine, sodium monofluoroacetate and bromobenzene. For five of the chemicals studied (not bromobenzene) there is a very good correlation between the cytotoxic effects in Chlorella cells measured by the algal growth inhibition test, and the inhibition of photosystem II activity. The results suggest that one very important effect of these chemicals in Chlorella cells is the inhibition of photosynthetic metabolism by the blocking of photosystem II functionality. In the case of sodium monofluoroacetate, diethanolamine and chloroquine this inhibition seems to be related with the induction of high level of lipid peroxidation in cells that may alter the stability of photosystem II. The results obtained by both techniques supply information that can be used as a supplement to the growth inhibition test and allows a more complete assessment of the effects of

Thermoluminescence dosimetry and its applications in medicine. Part 2: history and applications

International Nuclear Information System (INIS)

Kron, T.

1995-01-01

Thermoluminescence dosimetry (TLD) has been available for dosimetry of ionising radiation for nearly 100 years. The variety of materials and their different physical forms allow the determination of different radiation qualities over a wide range of absorbed dose. This makes TL dosimeters useful in radiation protection where dose levels of μ Gy are monitored as well as in radiotherapy where doses up to several Gray are to be measured. The major advantages of TL detectors are their small physical size and that no cables or auxiliary equipment is required during the dose assessment. TLD is considered to be a good method for point dose measurements in phantoms as well as for in vivo dosimetry on patients during radiotherapy treatment. As an integrative dosimetric technique, it can be applied to personal dosimetry and it lends itself to the determination of dose distributions due to multiple or moving radiation sources (e.g. conformal and dynamic radiotherapy, computed tomography). In addition, TL dosimeters are easy to transport, and they can be mailed. This makes them well suited for intercomparison of doses delivered in different institutions. The present article aims at describing the various applications TLD has found in medicine by taking into consideration the physics and practice of TLD measurements which have been discussed in the first part of this review. 198 refs., 4 tabs., 2 figs

Os eventos programados, como alternativo do desenvolvimento do turismo

Directory of Open Access Journals (Sweden)

Andrés Pinassi

2014-10-01

Full Text Available Turismo e lazer são vistos como uma alternativa para o desenvolvimento econômico, social e cultural de uma comunidade. Ambas práticas de lazer são consolidadas como processos sócio-espaciais que podem trazer muitos impactos benéficos para os moradores de uma determinada localidade. Assim, a dinâmica de eventos programados em aldeias visa proporcionar uma alternativa oportunidades de desenvolvimento local para comunidades carentes. Nesse contexto, a pesquisa desenvolvida, em seguida, analisa o desenvolvimento de um festival especial, realizada na Provincia de Buenos Aires (Argentina. Este festival, iniciado a partir da esfera pública municipal, mostrou benefícios económicos significativos e definir um entretenimento alternativa valiosa para a população local e da área de influência.

Curve thermoluminescent analysis of ZrO2 doped with nanoparticles and Ag nano fibers

International Nuclear Information System (INIS)

Mendoza A, D.; Villa S, G.; Gutierrez W, C.; Perez H, R.; Gonzalez M, P.

2008-01-01

This paper presents the results obtained from the analysis of the high temperature thermoluminescence response induced by UV radiation in pure zirconium (ZrO 2 ) and doped with Ag nanoparticles and Ag nano fibers. The zirconium samples were obtained by the sol-gel method and irradiated with a UV lamp for different times. The results showed that the presence of the dopants change the characteristics of the traps associated with the high temperature peak which is located at 230 C for pure zirconium, and that the greater influence is due the presence of Ag nano fibers, inducing a shift to lower temperatures. It also presents the thermoluminescence response as a function of irradiation time. (Author)

An investigation into the radiation damage of the silicon detectors of the H1-PLUG calorimeter within the HERA environment

International Nuclear Information System (INIS)

Hildesheim, W.; Seidel, M.

1995-07-01

The silicon detectors used in the H1-PLUG calorimeter have shown increasing aging effects during the '94 run period of the electron proton storage ring HERA. These effects were particularly manifest as degradation of the signal to noise level and the calibration stability. The reasons for this behaviour have been found to be correlated with radiation damage to the silicon oxide passivation edges of the detectors in strong and fluctuating increases of the leakage currents and in severe changes of the flat band voltages. Depletion voltages however are found to be stable and therefore bulk damage of the silicon can be excluded. A comparison with measurements made by thermoluminescence dosimeters as well as related laboratory experiments suggest that the aging is due to very low energetic electrons and photons. (orig.)

Dosimetric behavior of thermoluminescent dosimeters at low doses in diagnostic radiology

International Nuclear Information System (INIS)

Del Sol F, S.; Garcia S, R.; Guzman M, J.; Sanchez G, D.; Rivera M, T.; Ramirez R, G.; Gaona, E.

2015-10-01

Thermoluminescent (Tl) characteristics of TLD-100, LiF:Mg,Cu,P, and CaSO 4 : Dy the under homogeneous field of X-ray beams of diagnostic irradiation and its verification using thermoluminescent dosimetry is presented. The irradiations were performed utilizing an X-ray beam generated by a Radiology Mexican Company: MRH-II E GMX 325-AF SBV-1 model, with Rotating Anode X-Ray Tube installed in the Hospital Juarez Norte de Mexico in Mexico City. Different thermoluminescent characteristics of dosimetric material were studied, such as, batch homogeneity, Tl glow curve, Tl response as a function of X-ray dose, reproducibility and fading. Materials were calibrated in terms of absorbed dose to the standard calibration distance and positioned in a generic Phantom was used. Dose verification and comparison with the measurements made with that obtained by TLD-100 were analyzed. Preliminary results indicate the dosimetric peak appears at 243, 236 and 277 ± 5 degrees C respectively, these peaks are in agreement with that reported in the literature. Tl glow curve as a function of X-ray dose showed a linearity in the range from 1.76 mGy up to 14.70 mGy for all materials. Fading for a period of one month at room temperature showed low fading LiF:Mg,Cu,P, medium and high for TLD-100 and CaSO 4 : Dy. The results suggest that the three materials are suitable for measurements at low doses in radiodiagnostic, however, for its dosimetric characteristics are most effective for individual applications: personal dosimetry and monitors limb (LiF:Mg,Cu,P), clinical dosimetry and environmental (TLD-100 and CaSO 4 : Dy). (Author)

Thermoluminescence property of LiMgF{sub 3} erbium activated phosphor

Energy Technology Data Exchange (ETDEWEB)

Munoz, I.C. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, A.P. 130, Hermosillo, Sonora 83000 (Mexico); Cruz-Zaragoza, E., E-mail: ecruz@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, Mexico 04510 D.F. (Mexico); Favalli, A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Furetta, C. [Touro University Rome, Division of Touro College New York, Circne Gianicolense 15-17, 00153 Rome (Italy)

2012-05-15

The perovskite-like LiMgF{sub 3}:ErF{sub 3} pellets were obtained from the melt formed by LiF and MgF{sub 2} mixed salts in the stoichiometric ratio. The perovskite material was doped with 1, 2 and 4 mol% of ErF{sub 3} impurity. The pellets samples were {sup 60}Co gamma irradiated and their thermoluminescence (TL) properties were analyzed, i.e., dose-response, fading at RT and under UV irradiation, TL signal reproducibility, and kinetic parameters. The intensity of the TL response against irradiation dose was increased remarkably by the high concentration of impurity, and a linear dose-response was observed in the range of 1-10 Gy. The fading observed at RT was about 10-30% after 24 h from irradiation. All samples were exposed from 1 to 200 Gy gamma dose range. The TL glow peaks were found around 367-376, 438-447, 509-521, and 594-611 K, when the doped samples were 1, 2 and 4 mol% of the erbium impurity concentration. The thermoluminescence kinetics parameters of the glow curves have been analyzed using the Computerized Glow Curve Deconvolution (CGCD) method. - Highlights: Black-Right-Pointing-Pointer Perovskite-like LiMgF{sub 3} pellets were doped with 1, 2, and 4 mol% of ErF{sub 3} impurity. Black-Right-Pointing-Pointer Thermoluminescence properties and kinetics parameters were analyzed. Black-Right-Pointing-Pointer Dose-response, fading at RT and under UV irradiation and reproducibility are reported. Black-Right-Pointing-Pointer Four TL glow peaks were observed between 367 and 611 K, for all samples. Black-Right-Pointing-Pointer Glow curves have been analyzed using the CGCD method.

Past and future application of solid-state detectors in manned spaceflight

International Nuclear Information System (INIS)

Reitz, G.

2006-01-01

The radiation exposure in space missions can be reduced by careful mission planning and appropriate measures, such as provision of a radiation shelter, but it cannot be eliminated. The reason for that is the high penetration capability of the radiation components owing to their high energies. Radiation is therefore an acknowledged primary concern for manned spaceflight and is a potentially limiting factor for long-term orbital and interplanetary missions. The radiation environment is a complex mixture of charged particles of solar and galactic origin and of the radiation belts, as well as of secondary particles produced in interactions of the galactic cosmic particles with the nuclei of atmosphere of the earth. The complexity even increases by placing a spacecraft into this environment owing to the interaction of the radiation components with the shielding material. Therefore it is a challenge to provide for appropriate measurements in this radiation field, coping with the limited resources on experiment power and mass. Solid-state dosemeters were already chosen for measurements in the first manned flights. Thermoluminescence dosemeters (TLDs) and plastic nuclear track detectors (PNTD) especially found a preferred application because they are light-weighted, need no power supply and they are tissue-equivalent. Most of the data available until 1996 were gathered by using these passive detectors; this especially holds for heavy ion particle spectra. The systems, supplemented by converter foils or fission detectors and bubble detectors, provide information on dose, particle flux-, energy- and linear energy transfer spectra of the ionising radiation and neutron fluxes and doses. From 1989, silicon detectors were used for dose and flux measurements and later on for particle spectrometry. Silicon detectors were demonstrated as a powerful tool for the description of space radiation environment. Optical simulated luminescence (OSL) detectors have now been introduced as a

High dose thermoluminescence dosimetry performance of Sol-gel synthesized TiO{sub 2} phosphors

Energy Technology Data Exchange (ETDEWEB)

Salas J, Ch. J.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Castillo U, D. M.; Flores M, K. [Universidad de Sonora, Departamento de Ciencias Quimico Biologicas, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: castillouzeta@gmail.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, Queretaro, Qro. (Mexico)

2015-10-15

Full text: TiO{sub 2} is a ceramic material with many applications due to their different crystalline phases (rutile, anatase and brookite). It has attracted attention in several fields because their high mechanical strength, chemical stability and ion-conducting properties. Moreover, in recent years, some research groups gained interest in the thermoluminescence features of TiO{sub 2} concerning their potential use as thermoluminescence dosimeter. In this work, we present experimental results obtained in the first stage of a long-term research project focused in the synthesis of TiO{sub 2} phosphors for dosimetric applications. The thermoluminescent characterization of samples was carried out after being exposed to beta particle irradiation. TiO{sub 2} was prepared by alkoxide sol-gel route using titanium tetrabutoxide as precursor, ethanol, water and ammonia as catalyst. Pellet-shaped samples were annealed at 700 degrees C for 6 h in air atmosphere followed by slow cooling, and then were exposed to radiation doses from 25 to 400 Gy. The glow curves display maxima located at 103 and 238 degrees C when a 5 C/s heating rate is used. From the experimental results here presented, we conclude that TiO{sub 2} is a promising material to develop high dose Tl dosimeters. (Author)

Desenvolvimento e Gestão Pública: das ideias às práticas

Directory of Open Access Journals (Sweden)

Jackeline Amantino de Andrade

2010-11-01

Full Text Available Este artigo tem como objetivo tratar dos modelos de desenvolvimento no contexto brasileiro e introduzir uma discussão sobre políticas de desenvolvimento e sua gestão. Para tanto, faz-se necessário resgatar a discussão sobre desenvolvimento tanto em suas bases desenvolvimentistas como a atual proposição de desenvolvimento endógeno. Entende-se que o desenvolvimento depende de uma capacidade organizacional na articulação de vários fatores, tangíveis e intangíveis, quantitativos e qualitativos e envolve várias dimensões: econômica, social, cultural, ambiental e físico-territorial, político-institucional e científico-tecnológica e é construído através de estratégias processuais potencializadas por coletivos. A primeira parte apresenta uma discussão conceitual sobre o desenvolvimento e os processos de organizacionais e de gestão neles implicados. A segunda parte apresenta um estudo empírico de caráter exploratório de modo a ampliar a discussão sobre modelos de desenvolvimento a partir da relação entre teoria e prática. Finalmente, são tecidas algumas considerações sobre o por vir, principalmente, quando se considera que nesses tempos de globalização e de acirramento das desigualdades urge encontrar alternativas justas e solidárias para as sociedades.

Evaluation of new and conventional thermoluminescent phosphors for environmental monitoring using automated thermoluminescent dosimeter readers

International Nuclear Information System (INIS)

Rathbone, B.A.; Endres, A.W.; Antonio, E.J.

1994-10-01

In recent years, there has been considerable interest in a new generation of super-sensitive thermoluminescent (TL) phosphors for potential use in routine personnel and environmental monitoring. Two of these phosphors, α-Al 2 O 3 :C and LiF:Mg,Cu,P, are evaluated in this paper for selected characteristics relevant to environmental monitoring, along with two conventional phosphors widely used in environmental monitoring, LiF:Mg,Ti and CaF 2 :Dy. The characteristics evaluated are light-induced fading, light-induced background, linearity and variability at low dose, and the minimum measurable dose. These characteristics were determined using an automated commercial dosimetry system (Harshaw System 8800) and routine processing protocols. Annealing and readout protocols for each phosphor were optimized for use in a large-scale environmental monitoring program

Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

Energy Technology Data Exchange (ETDEWEB)

Iriqui R, J. L.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: jorgeiriqui@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

2015-10-15

Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (E{sub g} ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

Study of thermoluminescence response of purple to violet amethyst quartz from Balikesir, Turkey

International Nuclear Information System (INIS)

Nur, N.; Yeğingil, Z.; Topaksu, M.; Kurt, K.; Doğan, T.; Sarıgül, N.; Yüksel, M.; Altunal, V.; Özdemir, A.; Güçkan, V.; Günay, I.

2015-01-01

Highlights: • We reported on dosimetric characterisation of natural amethyst quartz specimens from Turkey, using TL technique. • The thermoluminescence characterisation tests were performed under the beta radiation exposure. • The IT peaks ∼230 °C show superlinear dose response behavior (g(D) > 1) between 1 Gy and 5 kGy. The HT peaks ∼300 °C show linear behavior (g(D) = 1) at low dose levels (1 < D < 20 Gy) and superlinearity (g(D) > 1) between 20 Gy < D < 2 kGy. • Deviations were determined for recycling measurements for various dose values of 0.1, 0.5, 0.8 and 1 kGy. • Amethyst quartz has great potential to be investigated for dosimetry purpose. - Abstract: In thermoluminescence (TL) dosimetry, the phosphor amethyst quartz as a thermoluminescent, appears to be one of the materials arousing the highest interest. In this study the dosimetric characteristics of natural amethyst quartz crystals collected from Balikesir–Dursunbey (Turkey) were investigated for the purpose of determination of the general properties that phosphors should have in order to be useful for thermoluminescence dosimetry. The natural thermoluminescence was drained by annealing the powder samples at 450 °C for 1.5 h. The effects of high temperature annealing, dose response curves, glow curves after a postirradiation annealing, reusability of the samples and storage of trapped electrons in dark at room temperature were clarified through irradiating the samples with the desired exposures by 90 Sr/ 90 Y beta particles. Isothermal annealing before and after irradiation was found to have a definite effect upon the TL glow curve of amethyst crystal powder. The same sample varied in sensitivity depending upon its previous thermal and radiation history. The peak heights of the glow peaks were examined with respect to dose response at dose levels between 1 Gy and 5 kGy. The intermediate temperature (IT) and high temperature (HT) peaks of 230 °C and 300 °C, respectively, exhibit dose�

Study of thermoluminescence response of purple to violet amethyst quartz from Balikesir, Turkey

Energy Technology Data Exchange (ETDEWEB)

Nur, N., E-mail: nnur@adiyaman.edu.tr [Adiyaman University, Engineering Faculty, Department of Electrical and Electronic Engineering, 02040 Adiyaman (Turkey); Yeğingil, Z.; Topaksu, M. [Cukurova University, Art and Sciences Faculty, Physics Department, 01330 Adana (Turkey); Kurt, K. [University of Mersin, Science and Art Faculty, Physics Department, 33343 Mersin (Turkey); Doğan, T. [Cukurova University, Vocational School of Imamoglu, Department of Technical Programs, 01700 Adana (Turkey); Sarıgül, N. [Institute of Nuclear Science, Hacettepe University, 06532 Ankara (Turkey); Yüksel, M.; Altunal, V.; Özdemir, A.; Güçkan, V. [Cukurova University, Art and Sciences Faculty, Physics Department, 01330 Adana (Turkey); Günay, I. [Cukurova University, Medicine Faculty, Biophysics Department, Adana (Turkey)

2015-09-01

Highlights: • We reported on dosimetric characterisation of natural amethyst quartz specimens from Turkey, using TL technique. • The thermoluminescence characterisation tests were performed under the beta radiation exposure. • The IT peaks ∼230 °C show superlinear dose response behavior (g(D) > 1) between 1 Gy and 5 kGy. The HT peaks ∼300 °C show linear behavior (g(D) = 1) at low dose levels (1 < D < 20 Gy) and superlinearity (g(D) > 1) between 20 Gy < D < 2 kGy. • Deviations were determined for recycling measurements for various dose values of 0.1, 0.5, 0.8 and 1 kGy. • Amethyst quartz has great potential to be investigated for dosimetry purpose. - Abstract: In thermoluminescence (TL) dosimetry, the phosphor amethyst quartz as a thermoluminescent, appears to be one of the materials arousing the highest interest. In this study the dosimetric characteristics of natural amethyst quartz crystals collected from Balikesir–Dursunbey (Turkey) were investigated for the purpose of determination of the general properties that phosphors should have in order to be useful for thermoluminescence dosimetry. The natural thermoluminescence was drained by annealing the powder samples at 450 °C for 1.5 h. The effects of high temperature annealing, dose response curves, glow curves after a postirradiation annealing, reusability of the samples and storage of trapped electrons in dark at room temperature were clarified through irradiating the samples with the desired exposures by {sup 90}Sr/{sup 90}Y beta particles. Isothermal annealing before and after irradiation was found to have a definite effect upon the TL glow curve of amethyst crystal powder. The same sample varied in sensitivity depending upon its previous thermal and radiation history. The peak heights of the glow peaks were examined with respect to dose response at dose levels between 1 Gy and 5 kGy. The intermediate temperature (IT) and high temperature (HT) peaks of 230 °C and 300 °C, respectively

Thermoluminescent dosimetric properties of Descalvado sand

International Nuclear Information System (INIS)

Teixeira, M.I.; Caldas, L.V.E.

2006-01-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ( 60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

Thermoluminescent dosimetry in veterinary diagnostic radiology

International Nuclear Information System (INIS)

Hernández-Ruiz, L.; Jimenez-Flores, Y.; Rivera-Montalvo, T.; Arias-Cisneros, L.; Méndez-Aguilar, R.E.; Uribe-Izquierdo, P.

2012-01-01

This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe. Personnel Dosimetry shows important measurements of daily workday in some persons near to the limit established by ICRP. TL results of radiation measurement suggest TLDs are good candidates as a dosimeter to radiation dosimetry in veterinary radiology. - Highlights: ► Personnel dosimetry in laboratory veterinary diagnostic was determined. ► Student workplaces are safe against radiation. ► Efficiency value of apron lead was determined. ► X-ray beams distribution into veterinarian laboratory was measured.

Thermoluminescent dosimetric properties of Descalvado sand

Energy Technology Data Exchange (ETDEWEB)

Teixeira, M.I.; Caldas, L.V.E

2006-07-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

Effect of low irradiation temperature on the thermoluminescent response of doped crystal NaCl:XCl2 :MnCl2(X=Ca, Cd)

International Nuclear Information System (INIS)

Ortiz M, A.; Cruz Z, E.; Furetta, C.; Kitis, G.

2009-10-01

Production of crystalline materials suitable thermoluminescent properties over a wide range of doses is becoming more important to evaluate different radiation fields. However, the thermoluminescence response and the structure of the glow curves may be modified by the participation of defects to low irradiation temperature. In this work it is analyzed the effect of the irradiation temperature, 77 and 200 K on the thermoluminescence response of crystal NaCl:XCl 2 :MnCl 2 (X=Ca, Cd) doubly doped. The glow curves obtained were analyzed using a deconvolution program of CGCD, and the response linearity was analyzed by supra linearity index. (Author)

Obtention of a thermoluminescent material for dosimetry of ionizing radiation; Obtencion de un material termoluminiscente para dosimetria de la radiacion ionizante

Energy Technology Data Exchange (ETDEWEB)

Gonzalez M, P R

1990-07-01

The thermoluminescent dosemeters are small crystals which suffer changes in their structure by the radiation effect, being displaced the electrons toward higher energy levels. On heating the previously irradiated crystals, the electrons come back to their base state emitting light photons. The light quantity emitted is proportional to the received radiation dose. The light quantity emitted is proportional to the received radiation dose. The lithium fluoride is one of the thermoluminescent materials considered as tissue equivalents by having a low effective atomic number (Z{sub ef}). At present, the more used commercial product used of this type is the TLD-100*. In this work the obtained results in the preparation of the lithium fluoride thermoluminescent material are presented. This is activated with magnesium (Mg) and titanium (Ti), which we have labelled as: LiF: Mg, Ti. The results from the tests performed for verifying his thermoluminescent properties are presented too, as powder form as in pellets form. These tests were performed in simultaneous form with TLD-100 samples, which is considered as reference. The LiF: Mg, Ti thermoluminescent material manufactured in the ININ presents similar dosimetric characteristics to those ones of the TLD-100. Therefore being able to replace the imported dosemeters. * (TLD-100 is a commercial trademark registered by Harshaw/Filtrol (US) for LiF: Mg, Ti Tl dosemeters) (Author)

Determination of the dose rapidity of a 90 Sr beta radiation source using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Gonzalez M, P.R.; Azorin N, J.; Rivera M, T.

2000-01-01

The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a 90 Sr- 90 Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)

Thermoluminescent of induced calcite by gamma and ultraviolet radiation

International Nuclear Information System (INIS)

Lima, J.F. de.

1987-01-01

Samples of brazilian calcite, exposed to gamma radiation in laboratory and heated at constant rate of 2.7 0 C/s, showed three glow peaks at 150, 250 and 350 0 C in their thermoluminescent emission curves. The analysis of these peaks, using different models, indicated that they follow a second order kinetics; it has been obtained, for the activation energy, 1.3, 1.5 and 1.7 eV, and, for the pre-exponential factors, 8.1 x 10 14 , 6.8 x10 13 and 2.4 x 10 12 s -1 . Although the total thermoluminescent emission has stayed constant, the relative height of glow peaks has changed with the temperature of annealing in the range of 400 to 700 0 C. Exposed samples were also illuminated with ultraviolet light and the resultant curves showed partial or total bleaching or some glow peaks and the growth of peaks at lower temperatures. Samples of virgin calcite, submited to increasing exposures of gamma rays, showed a corresponding enhancement of the optical absorption bands in the range of 25000 to 47000 cm -1 A subsequent illumination of these samples with ultraviolet light produced a decrease of the optical absorption bands at the same range. (author) [pt

The initial rise method extended to multiple trapping levels in thermoluminescent materials

Energy Technology Data Exchange (ETDEWEB)

Furetta, C. [CICATA-Legaria, Instituto Politecnico Nacional, 11500 Mexico D.F. (Mexico); Guzman, S. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Ruiz, B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Departamento de Agricultura y Ganaderia, Universidad de Sonora, A.P. 305, 83190 Hermosillo, Sonora (Mexico); Cruz-Zaragoza, E., E-mail: ecruz@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico)

2011-02-15

The well known Initial Rise Method (IR) is commonly used to determine the activation energy when only one glow peak is presented and analysed in the phosphor materials. However, when the glow peak is more complex, a wide peak and some holders appear in the structure. The application of the Initial Rise Method is not valid because multiple trapping levels are considered and then the thermoluminescent analysis becomes difficult to perform. This paper shows the case of a complex glow curve structure as an example and shows that the calculation is also possible using the IR method. The aim of the paper is to extend the well known Initial Rise Method (IR) to the case of multiple trapping levels. The IR method is applied to minerals extracted from Nopal cactus and Oregano spices because the thermoluminescent glow curve's shape suggests a trap distribution instead of a single trapping level.

The initial rise method extended to multiple trapping levels in thermoluminescent materials

International Nuclear Information System (INIS)

Furetta, C.; Guzman, S.; Ruiz, B.; Cruz-Zaragoza, E.

2011-01-01

The well known Initial Rise Method (IR) is commonly used to determine the activation energy when only one glow peak is presented and analysed in the phosphor materials. However, when the glow peak is more complex, a wide peak and some holders appear in the structure. The application of the Initial Rise Method is not valid because multiple trapping levels are considered and then the thermoluminescent analysis becomes difficult to perform. This paper shows the case of a complex glow curve structure as an example and shows that the calculation is also possible using the IR method. The aim of the paper is to extend the well known Initial Rise Method (IR) to the case of multiple trapping levels. The IR method is applied to minerals extracted from Nopal cactus and Oregano spices because the thermoluminescent glow curve's shape suggests a trap distribution instead of a single trapping level.

Thermoluminescence of KI:Eu2+ Stimulated by Ultraviolet Irradiation at Different Temperatures

International Nuclear Information System (INIS)

Aguirre de Carcer, I.; Jaque, F.; Townsend, P.D.

1999-01-01

The thermoluminescence (TL) of KI:Eu 2+ after ultraviolet (254 nm) irradiation at different temperatures from -40 deg. C to +40 deg. C has been studied. Two main glow peaks and some minor features have been identified on the thermoluminescence glow curves. Irradiating at low temperature gives a strong peak at γ5 deg. C and a less pronounced one at 230 deg. C. The TL glow peak emission spectra were analysed as consisting of the addition of several Gaussian shaped emission bands. The position of the Gaussian peaks, and their widths, are coincident with divalent europium emission at different sites of the KI:Eu 2+ system. A new emission band centred at 3.05 eV, 0.16 eV FWHM for Eu 2+ has been observed from the TL emission spectra. The changes in the spectral distribution of the TL emission with irradiation temperature are discussed. (author)

Desenvolvimento de um monitor de apneia pediátrico

OpenAIRE

Caldeira, Gonçalo José Martins

2009-01-01

O trabalho apresentado tem por base o desenvolvimento de um monitor de apneia do sono pediátrico. Aborda questões ao nível da fisiologia respiratória e da mecânica pulmonar de um indivíduo. Apresenta uma proposta de desenvolvimento de um monitor de aquisição e identificação de sinais respiratórios, a fim de efectuar a detecção da apneia do sono.

Desenvolvimento sustentável: um discurso sobre a relação entre desenvolvimento e natureza Sustainable development: a discourse about the relation between development and nature

Directory of Open Access Journals (Sweden)

Hugo Juliano Duarte Matias

2008-04-01

Full Text Available Trata-se do estudo de definições de desenvolvimento sustentável, elemento fundamental de repertórios interpretativos para a relação entre desenvolvimento e natureza. As definições respondiam a um questionário aplicado a 355 estudantes de vários cursos de uma universidade federal. Realizou-se uma análise de conteúdo que buscou a concepção de natureza e sua relação com desenvolvimento nessas definições. Foram encontradas três matrizes discursivas: (a "economicista" - a necessidade de desenvolvimento subordina a necessidade de preservação da natureza, cujo sentido é "recursos naturais"; (b discurso "bem intencionado" - a necessidade de desenvolvimento subordina a de preservação da natureza, cujo sentido é "fragilidade"; (c "esvaziado" - desenvolvimento e natureza são disjuntos. Conclui-se sobre a importância do estudo da atribuição de significado à natureza para explicar como as pessoas pensam a relação entre desenvolvimento e natureza, e sobre como essas matrizes discursivas podem justificar práticas sociais.This study presents the analysis of definitions of sustainable development, as a basic element of interpretative repertoires for the relation between development and nature. Three hundred and fifty five students of several courses of a federal university answered a questionnaire, providing the definitions, thereafter submitted to content analysis to examine the concept of nature and its relation with development. Three discursive matrixes were found: (a the "economic bias" one - the necessity of development subordinates the need of nature preservation nature is a "natural resources"; (b the "good intentions" discourse - the necessity of development subordinates the necessity of preservation - nature is "fragility"; (c the "empty" - one development and nature are separate. It is concluded that the attribution of meaning to nature is important to explain how people think about the relation between development and

Inglês como língua franca: desenvolvimentos recentes

Directory of Open Access Journals (Sweden)

Telma Gimenez

Full Text Available Em face da atual posição do inglês como uma língua franca global, este artigo tem como principal objetivo discutir os desenvolvimentos recentes dessa área, tomando como base os trabalhos apresentados durante a 7th International Conference on English as a Lingua Franca, realizada em Atenas, Grécia, em setembro de 2014. As reflexões, aprofundadas nos tópicos i Teorizações sobre ILF; ii ILF e formação de professores; iii Desenvolvimentos futuros, trazem um olhar analítico sobre os temas discutidos no evento. Espera-se que as informações e reflexões aqui contempladas possam contribuir para o desenvolvimento de uma "curiosidade acadêmica" a respeito do paradigma ILF (inglês como língua franca e para o engajamento com suas questões e implicações.

CERVEJA ARTESANAL E DESENVOLVIMENTO REGIONAL EM SANTA CATARINA (BRASIL

Directory of Open Access Journals (Sweden)

Valdinho Pellin

2016-12-01

Full Text Available Discussões relacionadas ao fortalecimento do desenvolvimento regional tem estimulado um debate em relação a contribuições que Indicações Geográficas (IGs podem oferecer ao desenvolvimento. IGs se constituem em elemento de identificação de produtos ou serviços com seus territórios e podem oferecer contribuições importantes para o desenvolvimento regional, agregando valor aos produtos, facilitando o acesso a novos mercados e valorizando tradições locais. Este artigo procura discutir a importância da cerveja artesanal no contexto do desenvolvimento regional em Santa Catarina. Para tanto explora como objetivos específicos: (i caracterizar as discussões que estão ocorrendo em torno do reconhecimento da IG para chope e cerveja artesanal na região de Blumenau (SC; (ii identificar contribuições e desafios para o Desenvolvimento Regional de um possível reconhecimento da IG; e (iii caracterizar limites e potencialidades sinalizados pela iniciativa em curso. Metodologicamente trata-se de pesquisa analítica e descritiva baseada em estudo de caso de natureza exploratória. Como instrumento de coleta de dados se realizou entrevistas semiestruturadas com gestores de micro cervejarias artesanais da região e atores públicos e privados envolvidos diretamente nas discussões. Além destas fontes primárias o estudo fundamentou-se em fontes consubstanciadas pelos documentos produzidos nas reuniões de trabalho realizadas até o presente. Os principais resultados de análise destacam que um possível reconhecimento da IG poderia contribuir para o fortalecimento do setor, aumentando a competitividade, além de fortalecer a atividade turística na região. Entretanto para isso, alguns conflitos, surgidos no âmbito das discussões, precisam ser assumidos, superados ou mitigados

Personnel radiation monitoring by thermoluminescence dosimetry (1995-96)

International Nuclear Information System (INIS)

Daw Mi Cho Cho; Daw Yi Yi Khin; Daw San San; U Maung Maung Tin; Daw Hla Hla Win

2001-01-01

Personnel radiation monitoring which is the dose assessment of individual doses from external radiation received by radiation workers has been carried out by Thermoluminescence Dosimetry system consisting of a Vinten Toledo TLD reader, LiF dosimeters and associated equipment. The exposed TLD dosimeters were measured by TLD reader and the dose evaluation and dose registration were done on personal computer. Due to the records of 1995-96, most of the radiation workers complied with the permissible dose recommended by IAEA and ICRP 60. (author)

Dating pleistocene fossil coastal sand dunes by thermoluminescence

International Nuclear Information System (INIS)

Poupeau, G.; Souza, J.H.; Soliani Junior, E.; Loss, E.L.

1983-01-01

It was shown recently that sunlight exposure is able to bleach most of the geological thermoluminescence (TL) of wind transported sediments. This property has been used in an attempt to date dunes from the well developed recent quaternary coastal dunes system of Rio Grande do Sul. Preliminary results presented here, show that TL dating on fossil sand dunes from Rio Grande do Sul should be possible in a time range from present to at least 50.000 yr and possibly more than 100.000 yr. (Author) [pt

Method of making isodose curve using thermoluminescence dosemeter

International Nuclear Information System (INIS)

Bakar Ramain, A.

1975-01-01

Line source of 60 Co in the form of needles and tubes are extensively used in radiotherapy in moulds, implants, and intracavitary techniques for the treatment of malignant lesions. It is important to have isodose distributions in tissue for those source for purposes of treatment planning. The isodose distributions have been obtained experimentally by using tinny lithium-fluoride (Lsub(i)F) thermoluminescent dosemeters (TLD) and they are compared to the theoretical results. The distinct advantages of Lsub(i)F (TLD) in such measurements are briefly discussed. (author)

Tutorial para o Desenvolvimento de Jogos 2D usando a Linguagem Java

Directory of Open Access Journals (Sweden)

Soraia Teixeira Barbosa

2015-07-01

Full Text Available Atualmente é grande o estudo e desenvolvimento de jogos eletrônicos tanto no meio acadêmico como fora dele. Entretanto o desenvolvimento do mesmo não é uma tarefa trivial. Este artigo mostra o desenvolvimento de um jogo computacional através de uma versão do conhecido jogo de arcade Space Invaders. O artigo proposto tem como objetivo mostrar os passos básicos para a construção de um jogo computacional em duas dimensões utilizando a linguagem de programação Java.

Issues in the reconstruction of environmental doses on the basis of thermoluminescence measurements in the Techa riverside

Science.gov (United States)

Bougrov, N. G.; Goksu, H. Y.; Haskell, E.; Degteva, M. O.; Meckbach, R.; Jacob, P.; Neta, P. I. (Principal Investigator)

1998-01-01

The potential of thermoluminescence measurements of bricks from the contaminated area of the Techa river valley, Southern Urals, Russia, for reconstructing external exposures of affected population groups has been studied. Thermoluminescence dating of background samples was used to evaluate the age of old buildings available on the river banks. The anthropogenic gamma dose accrued in exposed samples is determined by subtracting the natural radiation background dose for the corresponding age from the accumulated dose measured by thermoluminescence. For a site in the upper Techa river region, where the levels of external exposures were extremely high, the depth-dose distribution in bricks and the dependence of accidental dose on the height of the sampling position were determined. For the same site, Monte Carlo simulations of radiation transport were performed for different source configurations corresponding to the situation before and after the construction of a reservoir on the river and evacuation of the population in 1956. A comparison of the results provides an understanding of the features of the measured depth-dose distributions and height dependencies in terms of the source configurations and shows that bricks from the higher sampling positions are likely to have accrued a larger fraction of anthropogenic dose from the time before the construction of the reservoir. The applicability of the thermoluminescent dosimetry method to environmental dose reconstruction in the middle Techa region, where the external exposure was relatively low, was also investigated.

Development and characterization of the lead iodide semiconductor detector; Desenvolvimento e caracterizacao do detector semicondutor de iodeto de chumbo

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Icimone Braga de

2001-07-01

A methodology for purification and growth of PbI{sub 2} crystal as well as for its characterization as a room temperature radiation detector was developed in this work. Commercial salts were purified using the zone refining method and, for the purified material growth, the Bridgman method was used. To calculate the purification efficiency, studies of the decrease impurities concentrations were made in the salts and in three sections of the materials purified, using the neutron activation analysis technique. The results showed that the impurities segregate preferentially in the ingot final section. A significant decrease of the impurities concentration in function of the purification pass number was observed. The grown crystals presented good crystalline quality according to the results of the X-ray diffraction analysis. To evaluate the crystal as a semiconductor detector, measurements of dark leakage current, resistivity and the response of ({sup 241}Am) alpha particle and ({sup 241}Am, {sup 57}Co, {sup 133}Ba and {sup 137}Cs) gamma rays were carried out. The radiation response is strongly dependent on the crystals purity. The crystals purified with 500 passes exhibited energy resolution of 10% for {sup 241} Am alpha particle and the gamma rays resolution was compatible with the literature. The photosensibility of the PbI{sub 2} crystal found in the wavelength from 400 to 600 nm range suggests an another application at this crystal as a photodetector to be coupled to scintillators. (author)

Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

International Nuclear Information System (INIS)

Petitfils, A.

2007-09-01

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

DANÇA E O DESENVOLVIMENTO MOTOR DE PORTADORES DE NECESSIDADES EDUCATIVAS ESPECIAIS - PNEEs

Directory of Open Access Journals (Sweden)

Liliane de Oliveira

2012-04-01

Full Text Available O estudo objetivou verificar as modificações nos padrões de desenvolvimento motor de PNEEs mediante prática da dança. Participaram 14 PNEEs do CIEP/Cruz Alta. O instrumento foi a Escala de Desenvolvimento Motor (Rosa Neto, 1996. Utilizou-se a estatística descritiva e teste “t” para análise dos dados. Observou-se diferenças estatisticamente significativas (p<0,05 entre pré e pós-testes nas variáveis idade cronológica, motora geral, motricidade ampla e equilíbrio. Concluiu-se que o programa de dança contribuiu significativamente para o desenvolvimento motor de PNEEs. Palavras chave: dança, motor, desenvolvimento, especial, educação.

Elaboração e avaliação de um website sobre o desenvolvimento da linguagem infantil: portal dos bebês - desenvolvimento da linguagem

Directory of Open Access Journals (Sweden)

Aline Martins

2015-02-01

Full Text Available OBJETIVO: criar e desenvolver um website na área de fonoaudiologia com enfoque no desenvolvimento da linguagem de bebês de 0 a 48 meses, além de avaliar a qualidade do conteúdo apresentado e os recursos tecnológicos utilizados. MÉTODOS: na primeira fase do projeto foi realizado um levantamento de dados por meio de revisão de literatura sobre o desenvolvimento e aquisição da linguagem infantil. Em seguida esse conteúdo foi inserido no website e avaliado por 20 pais e/ou cuidadores. RESULTADO: o website Portal dos Bebês - Desenvolvimento da Linguagem foi desenvolvido com linguagem voltada a pais e/ou cuidadores, e seu conteúdo foi dividido em três temas: "Desenvolvimento da Linguagem", "Fala e Linguagem" e "Linguagem e o Ambiente". No que se refere à qualidade do conteúdo e da apresentação, o website foi avaliado como "excelente" por todos os participantes da amostra. Quanto à avaliação sobre o vocabulário utilizado e a forma de apresentação do conteúdo, 70% e 75% respectivamente, consideraram o website como "excelente". Em relação à apresentação visual, 85% dos participantes classificaram como "excelentes", já o tipo de navegação foi classificado como "satisfatório" por 50% dos participantes. Quanto à importância que os pais e/ou cuidadores julgam sobre o site a maioria classificou como "excelente" o auxilio que o mesmo dá no desenvolvimento da linguagem da criança. CONCLUSÃO: o website Portal dos Bebês - Desenvolvimento da Linguagem pode ser acessado pelo endereço online http://portaldosbebes.fob.usp.br, e seu conteúdo e recursos tecnológicos utilizados foram avaliados como satisfatório a excelente pelos pais e/ou cuidadores participantes.

Development of Mg B4 O7:Dy thermoluminescent solid dosemeter for using on the thermal neutron dosimetry

International Nuclear Information System (INIS)

Potiens Junior, A.J.; Campos, L.L.; Todo, A.S.

1992-01-01

The magnesium tetraborate doped with dysprosium (Mg B 4 O 7 :O y ) thermoluminescent phosphor is developed, containing boron, which boron 10 isotope has high cross section for thermal neutrons by 10 B (n,α) 7 Li reaction. The nitric acid concentration, the number of washing for removing the excess of boric acid, the powder granulation of Mg B 4 O 7 :O y , the percentage of teflon used as binder and the reproducibility of thermoluminescent answer are also presented. (C.G.C.)

Personnel radiation dosimetry laboratory accreditation programme for thermoluminescent dosimeters : a proposal

International Nuclear Information System (INIS)

Bhatt, B.C.; Srivastava, J.K.; Iyer, P.S.; Venkatraman, G.

1993-01-01

Accreditation for thermoluminescent dosimeters is the process of evaluating a programme intending to use TL personnel dosimeters to measure, report and record dose equivalents received by radiation workers. In order to test the technical competence for conducting personnel dosimetry service as well as to decentralize personnel monitoring service, it has been proposed by Radiological Physics Division (RPhD) to accredit some of the laboratories, in the country. The objectives of this accreditation programme are: (i) to give recognition to competent dosimetry processors, and (ii) to provide periodic evaluation of dosimetry processors, including review of internal quality assurance programme to improve the quality of personnel dosimetry processing. The scientific support for the accreditation programme will be provided by the scientific staff from Radiological Physics Division (RPhD) and Radiation Protection Services Division (RPSD). This paper describes operational and technical requirements for the Personnel Radiation Dosimetry Laboratory Accreditation Programme for Thermoluminescent Dosimeters for Personnel Dosimetry Processors. Besides, many technical documents dealing with the TL Personnel Dosimeter System have been prepared. (author). 5 refs., 2 figs

A thermoluminescence study of vempalle dolomites and its depositional environments

International Nuclear Information System (INIS)

Bhattacharya, A.K.; Rao, C.N.; Kaul, I.K.

1976-01-01

An attempt has been made to interpret the depositional environment of Vempalle dolomites (India) by thermoluminescence method. It has been demonstrated that glow curve patterns reflect the environmental condition of deposition for carbonate sediments. The glow curves were obtained for natural samples as well as samples irradiated by Co 60 and compared. A majority of the samples were concluded to be diagenetic. (A.K.)

A COMPLEXIDADE ECONÔMICA DOS DIREITOS HUMANOS: UMA DIMENSÃO ESCONDIDA DO DESENVOLVIMENTO HUMANO

Directory of Open Access Journals (Sweden)

Leilane Serratine Grubba

2012-10-01

Full Text Available Este artigo tem por objeto a complexidade econômica dos direitos humanos, mais precisamente, a investigação da relação entre a complexidade econômica e o desenvolvimento humano. Nesse sentido, objetivou demonstrar a intrínseca relação e dependência do desenvolvimento humano à complexidade econômica dos direitos humanos, que influi na positivação dos direitos, assim como na luta pelo acesso aos bens necessários a uma vida digna. Por meio do método dedutivo, o artigo problematizou a relação entre o ser humano e seu contexto econômico-social para o desenvolvimento da vida em dignidade. Diante disso, em primeiro lugar, foi apresentada a noção de complexidade dos direitos humanos, isto é, as suas múltiplas dimensões. No segundo momento, foi analisada a questão econômica do desenvolvimento humano, ou seja, a relação entre o desenvolvimento da vida digna e a dimensão econômica da sociedade, e, finalmente, foi apresentada a complexidade econômica dos direitos humanos. O desenvolvimento humano não está apenas vinculado à dimensão econômica, mas compreende todas as dimensões (complexidade que perfazem uma vida digna de ser vivida. A vida se desenvolve em dignidade mediante o acesso aos bens materiais e imateriais. As políticas do desenvolvimento humano, nesse sentido, devem se integrar a uma estrutura que apoie um crescimento com equidade e sustentabilidade. Palavras-chave: Pensamento complexo. Complexidade econômica. Direitos humanos. Desenvolvimento humano. Dignidade humana.

The initial rise method extended to multiple trapping levels in thermoluminescent materials.

Science.gov (United States)

Furetta, C; Guzmán, S; Ruiz, B; Cruz-Zaragoza, E

2011-02-01

The well known Initial Rise Method (IR) is commonly used to determine the activation energy when only one glow peak is presented and analysed in the phosphor materials. However, when the glow peak is more complex, a wide peak and some holders appear in the structure. The application of the Initial Rise Method is not valid because multiple trapping levels are considered and then the thermoluminescent analysis becomes difficult to perform. This paper shows the case of a complex glow curve structure as an example and shows that the calculation is also possible using the IR method. The aim of the paper is to extend the well known Initial Rise Method (IR) to the case of multiple trapping levels. The IR method is applied to minerals extracted from Nopal cactus and Oregano spices because the thermoluminescent glow curve's shape suggests a trap distribution instead of a single trapping level. Copyright © 2010 Elsevier Ltd. All rights reserved.

Thermoluminescence study of aluminium oxide doped germanium prepared by combustion synthesis method

Directory of Open Access Journals (Sweden)

Saharin Nurul Syazlin Binti

2017-01-01

Full Text Available The present paper reports the optimum concentration of germanium (Ge dopant in aluminium oxide (AhO3 samples prepared by combustion synthesis (CS method for thermoluminescence (TL studies. The samples were prepared at various Ge concentration i.e. 1 to 5% mol. The phase formation of un-doped and Ge-doped Al2O3 samples was determined using X-ray Diffraction (XRD. The sharp peaks present in the XRD pattern confirms the crystallinity of the samples. The samples were then exposed to 50 Gy Cobalt-60 sources (Gamma cell 220. TL glow curves were measured and recorded using a Harshaw Model 3500 TLD reader. Comparison of TL peaks were observed to obtain the best composition of Ge dopants. A simple glow curves TL peak at around 175̊C for all composition samples was observed. It was also found that the composition of aluminium oxide doped with 3.0% of germanium exhibits the highest thermoluminescence (TL intensity which is 349747.04 (a.u.

Measurement of thermoluminescence - a new method for detecting radiation treatment of spices. Die Messung der Thermolumineszenz - ein neues Verfahren zur Identifizierung strahlenbehandelter Gewuerze

Energy Technology Data Exchange (ETDEWEB)

Heide, L; Boegl, W

1984-12-01

By the experiments described in this report it was examined in 14 different spices to which extent measurements of thermoluminescence intensity of up to 300/sup 0/C are suitable for detecting treatment with ionizing radiation. The optimal weight of each spice was first determined for a later investigation of the dependence of thermoluminescence intensity on dose and postirradiation storage. In most spices, radiation treatment is detectable as long as after a storage period of over 2 months. In general it may be stated that thermoluminescence measurement is a reliable method for detecting radiation treatment in supplement to chemiluminescence measurement.

On the second kinetic order thermoluminescent glow curves

International Nuclear Information System (INIS)

Dang Thanh Luong; Nguyen Hao Quang; Hoang Minh Giang

1995-01-01

The kinetic parameters of thermoluminescent material such as CaF 2 -N and CaSO 4 -Dy with the different grain sizes are investigated in detail using the least square method of fitting. It was found that the activation energy E (or trap depth) and peak temperature T m ax are changed with the elapsed time between the irradiation and read-out for the low temperature glow curve peaks. The similar TL glow curve shapes are obtained for the different CaSO 4 -Dy grain size. (author). 7 refs., 5 figs., 2 tabs

Thermoluminescent dosemeter in a X-ray diffractometer; Dosimetria termoluminiscente en un difractometro de rayos X

Energy Technology Data Exchange (ETDEWEB)

Mendoza A, D.; Gonzalez M, P.; Falcon B, T. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico); Castano, V.M. [Instituto de Fisica, UNAM, Laboratorio Juriquilla, A.P. 1-1010, C.P. 76001, Queretaro (Mexico)

1999-07-01

In this work it was presented the results obtained of the dosimetry which was realized in a X-ray diffractometer for powders, trademark Siemens D5000, using the thermoluminescent signal generated by the X-rays in the commercial dosemeter TLD-100 of Harshaw, US. In according to the results obtained, the radiation quantity received by an analysed material in the diffractometer, will be proportional to exposure time and it can vary from unities until tenths of grays. These results are very outstanding when are analysed crystalline materials in a diffractometer, for knowing the present crystalline phases, mainly if these are highly sensitive to the ionizing radiation, as it is the case of the thermoluminescent materials. (Author)

An integral equation method for discrete and continuous distribution of centres in thermoluminescence kinetics

International Nuclear Information System (INIS)

Kantorovich, L.N.; Fogel, G.M.; Gotlib, V.I.

1990-01-01

Thermoluminescence kinetics is discussed within the framework of a band model containing an arbitrary number of types of recombination and trapping centres at an arbitrary correlation of all centre parameters. It is shown that the initial system of kinetic equations is reduced to an equivalent system consisting of two integro-differential equations which permit one to perform an accurate generalisation, in the case of a continuous centre distribution, to their parameters for the description of irradiation and thermoluminescence, taking into account charge carrier redistribution to both types of centre. In addition, if only one electron (hole) channel is taken into account, only one integro-differential equation is obtained. On the basis of this equation a precise algebraic equation is obtained for calculation of the area of an arbitrary part of the thermoluminescence curve (TLC), consisting of one or several peaks, which slightly overlap with other peaks. It is shown that at doses which are less than the saturation dose, when the centres are not completely filled by the charge carriers, the dose dependences of such a part of the TLC may have a non-linear character at a simultaneous linear dependence of the area of the whole TLC. At doses which are greater than the saturation dose, the dose dependences of the area of the whole TLC, as well as of its separate parts, undergo breaks at the saturation doses. (author)

Dosimetry of accidents using thermoluminescence of dental restorative porcelains

International Nuclear Information System (INIS)

Mauricio, C.L.P.; Rosa, L.A.R. da; Cunha, P.G. da

1986-01-01

The thermoluminescence (TL) properties of dental restorative porcelain were investigated with the aim of using this material as a TL dosemeter to estimate high doses in radiological accidents. The irradiations were carried out with a 60 Co gamma source and X rays with effective energies from 29 to 95 KeV. The samples have a limit of detection at about 50R and their reproducibility is better than 15%. Linearity was observed from 50 to 5000R. (Author) [pt

Development of TiBr semiconductor crystal for applications as radiation detector and photodetector; Desenvolvimento do cristal semicondutor de brometo de talio para aplicacoes como detector de radiacao e fotodetector

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Icimone Braga de

2006-07-01

In this work, Tlbr crystals were grown by the Bridgman method from zone melted materials. The influence of the purification efficiency and the crystalline surface quality on the crystal were studied, evaluating its performance as a radiation detector. Due to significant improvement in the purification and crystals growth, good results have been obtained for the developed detectors. The spectrometric performance of the Tlbr detector was evaluated by {sup 241}Am (59 keV), {sup 133}Ba (80 e 355 keV), {sup 57}Co (122 keV), {sup 22}Na (511 keV) and {sup 137} Cs (662 keV) at room temperature. The best energy resolution results were obtained from purer detectors. Energy resolutions of 10 keV (16%), 12 keV (15%), 12 keV (10%), 28 keV (8%), 31 keV (6%) and 36 keV (5%) to 59, 80, 122, 355, 511 and 662 keV energies, respectively, were obtained. A study on the detection response at -20 deg C was also carried out, as well as the detector stability in function of the time. No significant difference was observed in the energy resolution between measurements at both temperatures. It was observed that the detector instability causes degradation of the spectroscopic characteristics during measurements at room temperature and the instability varies for each detector. This behavior was also verified by other authors. The viability to use the developed Tlbr crystal as a photodetector coupled to scintillators crystals was also studied in this work. Due to its quantum efficiency in the region from 350 to 500 nm, Tlbr shows to be a promising material to be used as a photodetector. As a possible application of this work, the development of a surgical probe has been initiated using the developed Tlbr crystal as the radiation detector of the probe. (author)

Dose profile measurement in computerized axial tomography equipment using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Azorin V, J.C.; Falcony, C.; Azorin N, J.

2000-01-01

In this work are presented the results about measuring the radiation dose profile in two equipment of computerized axial tomography (Tac). Thermoluminescent dosemeters (Dtl) of LiF, Mg, Cu, P + Ptfe in form of disks were used which were developed and made in Mexico. The results showed that Dtl are appropriated for these type of studies. (Author)

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

Thermoluminescence of Stoichiometric Magnesium-Aluminium Spinel Defects

International Nuclear Information System (INIS)

Kobyakov, V.A.; Gritsina, V.T.; Kazarinov, Yu.G.; Volokitin, V.N.

2005-01-01

The investigations of thermoluminescence of spinel single crystals MgAl 2 O 4 after UV- and X-ray irradiation was provided by using method of self consisting heating. It was shown, that observed maxima at temperatures of ∼360 and ∼530 K in UV- and green ranges of spectra, respectively, are complex and consist of several strongly overlapping partial maxima. By using method of self consisting heating we have revealed the approximate position of partial maxima, which are included in maxima of ∼360 and ∼530 K, and for some partial maxima there was obtained the order of kinetics, activation energies, and frequency factors

Thermoluminescent dosimetry of beta radiations of 90 Sr/ 90 Y using amorphous ZrO2

International Nuclear Information System (INIS)

Rivera M, T.; Olvera T, L.; Azorin N, J.; Barrera R, M.; Soto E, A.M.

2005-01-01

In this work the results of studying the thermoluminescent properties (Tl) of the zirconium oxide in its amorphous state (ZrO 2 -a) before beta radiations of 90 Sr/ 90 Y are presented. The amorphous powders of the zirconium oxide were synthesized by means of the sol-gel technique. The sol-gel process using alkoxides like precursors, is an efficient method to prepare a matrix of zirconium oxide by hydrolysis - condensation of the precursor to form chains of Zr-H 3 and Zr-O 2 . One of the advantages of this technique is the obtention of gels at low temperatures with very high purity and homogeneity. The powders were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO 2 -a, previously irradiated with beta particles of 90 Sr/ 90 Y, presented a thermoluminescent curve with two peaks at 150 and 257 C. The dissipation of the information of the one ZrO 2 -a was of 40% the first 2 hours remaining constant the information for the following 30 days. The reproducibility of the information was of ± 2.5% in standard deviation. The studied characteristics allow to propose to the amorphous zirconium oxide as thermoluminescent dosemeter for the detection of beta radiation. (Author)

Thermoluminescent dosimetry of beta radiations of 90 Sr/ 90 Y using ZrO2: Eu

International Nuclear Information System (INIS)

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

2005-01-01

In this work the results of studying the thermoluminescent properties (TL) of the doped zirconium oxide with europium (ZrO 2 : Eu 3+ ) before beta radiations of 90 Sr/ 90 Y are presented. The powders of ZrO 2 : Eu 3+ were obtained by means of the sol-gel technique and they were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO 2 : Eu 3+ , previously irradiated with beta particles of 90 Sr/ 90 Y, presented a thermoluminescent curve with two peaks at 204 and 292 C respectively. The TL response of the ZrO 2 : Eu 3+ as function of the absorbed dose was lineal from 2 Gy up to 90 Gy. The fading of the information of the ZrO 2 : Eu 3+ was of 10% the first 2 hours remaining almost constant the information by the following 30 days. The ZrO 2 doped with the (Eu 3+ ) ion it was found more sensitive to the beta radiation that the one of zirconium oxide without doping (ZrO 2 ) obtained by the same method. Those studied characteristics allow to propose to the doped zirconium oxide with europium like thermoluminescent dosemeter for the detection of the beta radiation. (Author)

Energy absorption buildup factors for thermoluminescent dosimetric materials and their tissue equivalence

DEFF Research Database (Denmark)

Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

2010-01-01

Gamma ray energy-absorption buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for seven thermoluminescent dosimetric (TLD) materials in the energy range 0.015-15 MeV, and for penetration depths up to 40 mfp (mean free path). The generated energy-absorption...

Characterization of nanoDot optically stimulated luminescence detectors and high-sensitivity MCP-N thermoluminescent detectors in the 40-300 kVp energy range.

Science.gov (United States)

Poirier, Yannick; Kuznetsova, Svetlana; Villarreal-Barajas, Jose Eduardo

2018-01-01

To investigate empirically the energy dependence of the detector response of two in vivo luminescence detectors, LiF:Mg,Cu,P (MCP-N) high-sensitivity TLDs and Al 2 O 3 :C OSLDs, in the 40-300-kVp energy range in the context of in vivo surface dose measurement. As these detectors become more prevalent in clinical and preclinical in vivo measurements, knowledge of the variation in the empirical dependence of the measured response of these detectors across a wide spectrum of beam qualities is important. We characterized a large range of beam qualities of three different kilovoltage x-ray units: an Xstrahl 300 Orthovoltage unit, a Precision x-Ray X-RAD 320ix biological irradiator, and a Varian On-Board Imaging x-ray unit. The dose to water was measured in air according to the AAPM's Task Group 61 protocol. The OSLDs and TLDs were irradiated under reference conditions on the surface of a water phantom to provide full backscatter conditions. To assess the change in sensitivity in the long term, we separated the in vivo dosimeters of each type into an experimental and a reference group. The experimental dosimeters were irradiated using the kilovoltage x-ray units at each beam quality used in this investigation, while the reference group received a constant 10 cGy irradiation at 6 MV from a Varian clinical linear accelerator. The individual calibration of each detector was verified in cycles where both groups received a 10 cGy irradiation at 6 MV. The nanoDot OSLDs were highly reproducible, with ±1.5% variation in response following >40 measurement cycles. The TLDs lost ~20% of their signal sensitivity over the course of the study. The relative light output per unit dose to water of the MCP-N TLDs did not vary with beam quality for beam qualities with effective energies <50 keV (~150 kVp/6 mm Al). At higher energies, they showed a reduced (~75-85%) light output per unit dose relative to 6 MV x rays. The nanoDot OSLDs exhibited a very strong (120

Thermoluminescence of Zn O thin films deposited by chemical bath; Termoluminiscencia de peliculas delgadas de ZnO depositadas por bano quimico

Energy Technology Data Exchange (ETDEWEB)

Camacho A, M. C.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal H, R.; Berman M, D. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Castano M, V. M., E-mail: carmencamacho@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

2015-10-15

Full text: Zn O films on Si were synthesized using a deposition method by chemical bath and thermally treated at 900 degrees C for 12 h in air. The morphological characterization by scanning electron microscopy reveals that uniform films were obtained. To investigate the thermoluminescent properties of the films were exposed to irradiation with beta particles with doses in the range from 0.5 to 128 Gy. The brightness curves obtained using a heating rate of 5 degrees C have two peaks, one at 124 and another at 270 degrees C, and a linear dependence of the integrated thermoluminescence as a function of dose. The second maximum reveals the existence of localized trapping states of potential utility in thermoluminescent dosimetry. (Author)

Thermoluminescence glow curve analysis and CGCD method for erbium doped CaZrO{sub 3} phosphor

Energy Technology Data Exchange (ETDEWEB)

Tiwari, Ratnesh, E-mail: 31rati@gmail.com [Department of Physics, Bhilai Institute of Technology, Raipur, 493661 (India); Chopra, Seema [Department Physics, G.D Goenka Public School (India)

2016-05-06

The manuscript report the synthesis, thermoluminescence study at fixed concentration of Er{sup 3+} (1 mol%) doped CaZrO{sub 3} phosphor. The phosphors were prepared by modified solid state reaction method. The powder sample was characterized by thermoluminescence (TL) glow curve analysis. In TL glow curve the optimized concentration in 1mol% for UV irradiated sample. The kinetic parameters were calculated by computerized glow curve deconvolution (CGCD) techniaue. Trapping parameters gives the information of dosimetry loss in prepared phosphor and its usability in environmental monitoring and for personal monitoring. CGCD is the advance tool for analysis of complicated TL glow curves.

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

A comparative thermoluminescence and electron spin resonance study of synthetic carbonated A-type hydroxyapatite

International Nuclear Information System (INIS)

Oliveira, L.C.; Rossi, A.M.; Baffa, O.

2012-01-01

Intensity of the 150 °C thermoluminescence peak of beta-irradiated carbonated synthetic A-type hydroxyapatite is approximately 12 times higher than that of the noncarbonated material. Deconvolution of the glow curve showed that this peak is a result of a trap distribution. An attempt was made to relate this thermoluminescence peak enhanced by carbonation with the ESR signal of the CO 2 − radical in natural or synthetic hydroxyapatite. - Highlights: ► Synthetic hydroxyapatite was carbonated with CO 2 . ► TL enhanced by 12 times in carbonated synthetic A-type hydroxyapatite. ► EPR and TL were performed to find out a relation between CO 2 − center and the TL. ► No direct relation was found between the CO 2 − center and TL enhancement.

Thermoluminescence as a tool for monitoring ozone-stressed plants

Energy Technology Data Exchange (ETDEWEB)

Skotnica, J.; Gilbert, M.; Weingart, I.; Wilhelm, C

2003-05-01

Thermoluminescence parameters are more sensitive to ozone than fluorescence parameters (F{sub 0}, F{sub M}, F{sub v}/F{sub M}). - The effect of ozone (6 h, various concentrations from 0 to 350 ppb) on barley (Hordeum vulgare L., cv. Bomi) and tomato (Lycopersicon esculentum L., cv. Yellow Cherry) leaves was investigated in parallel by thermoluminescence (TL) and fluorescence (FL) methods. Several significant changes were found in TL glow curves measured after excitation by one single turnover flash at +2 deg. C in the temperature range from 2 to 170 deg. C immediately after ozone exposure. Contrary to TL, ozone induced only negligible changes in FL parameters F{sub 0}, F{sub M} and F{sub v}/F{sub M}. Measurements done 24 h after ozone exposure showed partial recovery of ozone-induced changes. The extent of recovery was not the same in different parts of TL curves. Fluorescence parameters were not significantly changed. The results demonstrate that TL parameters are more sensitive to ozone than conventially used FL parameters F{sub 0}, F{sub M} and F{sub v}/F{sub M}. Moreover, TL measurements seem to give information not only about the PSII electron transport, but also about the extent of oxidative damage and membrane lipid peroxidation. It is concluded, that TL can be a highly informative tool for monitoring the impact of ozone on plants.

Thermoluminescent response of LiF before variation of the heating rate; Respuesta termoluminiscente de LiF ante variacion de la tasa de calentamiento

Energy Technology Data Exchange (ETDEWEB)

Barrios, R. [Facultad de Quimica, UAEM, 50000 Toluca, Estado de Mexico (Mexico); Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2003-07-01

Comparisons of glow curves of lithium fluoride dosemeters TLD-100 measured to two heating rates with the purpose of quantifying the change in the temperature of the peaks 5 and 7 for the thermoluminescent reader equipment Harshaw 4000 of the thermoluminescence laboratory of the ININ were carried out. (Author)

Confrontation of thermoluminescence models in lithium fluoride with experimental data

International Nuclear Information System (INIS)

Niewiadomski, T.

1976-12-01

The thermoluminescent properties of lithium fluoride depend on numerous factors and are much more complex than those of other phosphors. The so far developed fragmentary models are meant to explain the relationships between crystal defect structure and the processes involved in TL. An attempt has been made to compare these models with the veryfied experimental data and to point out the observations which are inconsistant with the models. (author)

Substance for thermoluminescent dosimetry of photon radiation in adipose tissue

International Nuclear Information System (INIS)

Kalmykov, L.Z.; Kandel', T.G.

1983-01-01

Substance composition for thermoluminescent photon dosimetry in adipose tissue is proposed which makes it possible to simplify dosimetric measurements and to improve their accuracy. The substance consists of powder-like thermoluminophor Li 2 B 4 O 7 (0.03%Mn) 48-52 mass % and bistriethylammonium dodecahydrododecaborane - 48-52 mass %. The above substance is equivalent in respect to dosimetry to adipose tissue within the 10 keV - 10 MeV energy range

Irradiated Foods Detection by Thermoluminescence (TL) and DEFT/APC Analysis

International Nuclear Information System (INIS)

Choi, I.D.; Kang, E.K.; Yang, J.S.

2004-01-01

Irradiated food detection methods such as Thermoluminescence (TL) and Direct Epifluorescent Filter Technique and Aerobic Plate Count (DEFT/APC) methods were evaluated. Fresh green-onion, onion, and ginger were irradiated at 0, 0.3, 0.6, and 0.9 kGy. Difference in log DEFT/APC units between irradiated and un-irradiated samples was less than 2 long units, below the average threshold value (3-4 long units) of international researches

Thermal and radiation history of meteorites as revealed by their thermoluminescence records

International Nuclear Information System (INIS)

Bhandari, N.

1985-01-01

Attempts are described to derive information about important parameters of the thermal and radiation history of meteorites from a study of depth profile of thermoluminescence coupled to appropriate annealing studies. In this review some possibilities are examined, emphasizing various factors cardinal to any meaningful application of TL in meteoritics. (author)

Solid thermoluminescent dosemeter of sodium tetraborate and brazilian fluoride sensitive to thermal neutrons

International Nuclear Information System (INIS)

Fratin, L.

1988-01-01

The techniques of compacting sodium tetraborate and natural fluoride mixtures were studied in this work, with the aim of producing a solid dosimeter sensitive to thermal neutrons. The production procedure involves the vitrification of the sodium tetraborate, the grinding, mixture, cold pressing and the sinterization of the pellets. A special arrangement was built for irradiation where paraffin was used as moderator for neutrons from a 241 Am-Be source. Two different mass ratios of sodium tetraborate and flourite showed a linear thermoluminescent response to the neutron fluence in the range of 1.0 to 7.0 x 10 8 n (sub)tcm -2 . Solid dosimeters, manufactured from natural fluorite and sodium chloride, showed a response to gamma radiation similar to the response of the dosimeters sensitive to neutrons. These dosimeters are need to identify the proportion of thermoluminescent response due to gamma radiation present in a neutron field. (author) [pt

Macroscopic polarization and thermoluminescence of barium niobate - sodium niobate

International Nuclear Information System (INIS)

Gorban', I.S.; Gumenyuk, A.F.; Omel'yanenko, V.A.

1989-01-01

Thermoluminescence (TL) of initial and thermally treated purposely undoped crystals of barium niobate - sodium has been studied within 85-400 K. The TL intensity is found to depend on the temperature to which the sample has been heated. A conclusion is drawn that nonstationarity of the TL properties is due to slowly occuring processes of compensation of pyrocharge, which depend on the temperatural prehistory of the sample. A mechanism of the traps transformation in a strong pyrofield of high-impedance crystals is discussed

Preparation Of Thermoluminescence Dosimeters For External Radiotherapy Beam Audit In Malaysia

International Nuclear Information System (INIS)

Norhayati Abdullah; Siti Sara Deraman; Taiman Kadni; Mohd Taufik Dollah; Norhayati Salleh

2014-01-01

The external beam audit is a part of the Quality Assurance Programme (QAP) in radiotherapy that should be carried out to check the accuracy of dose delivered by the radiotherapy treatment units are within the tolerance limit of A ± 5 % as recommended by the International Commission of Radiation Units and Measurements (ICRU) Report No. 24. In this work, thermoluminescence dosimeters (TLD) in powder form were chosen to be used in the dose quality audit for the radiotherapy treatment units in Malaysia. As a preparation, the characterizations of a new batch of TLD-100 powders were studied. The studies include checks for the response of TLD-100 before and after pre-annealing process, reproducibility and linearity of TL signal. Results show that the response of TLD-100 powder after pre-annealing increases by 65 % compared with before pre-annealing process. These TLD-100 powders also provide reliable and consistent readings for the absorbed dose to water within the range of 150 cGy to 250 cGy with the maximum standard uncertainty of 0.554 μC. Finally, the calibration curves for 6 MV and 10 MV photon beams were established. These curves will be used in determining the absorbed dose to water (Dw) from user's irradiated TLDs. The expanded uncertainty (coverage factor k=2) of Dw determination was estimated to be 4.1 %. As a conclusion, these TLD-100 powders are ready to be used as a transfer detector for evaluating the accuracy of user's delivery dose in the radiotherapy beam audit program in Malaysia. (author)

Thermoluminescence properties of CaO powder obtained from chicken eggshells

International Nuclear Information System (INIS)

Nagabhushana, K.R.; Lokesha, H.S.; Satyanarayana Reddy, S.; Prakash, D.; Veerabhadraswamy, M.; Bhagyalakshmi, H.; Jayaramaiah, J.R.

2017-01-01

Eggshell wastage has created serious problem in disposal of the food processing industry which has been triggered the thoughts of researchers to use wasted eggshells as good source of calcium. In the present work, calcium oxide (CaO) has been synthesized by combustion process in furnace (F–CaO) and microwave oven (M–CaO) using the source of chicken eggshells. The obtained F–CaO and M–CaO are characterized by XRD, SEM with EDX and thermoluminescence (TL) technique. XRD pattern of both the samples show cubic phase with crystallite size 45–52 nm. TL glow curves are recorded for various gamma radiation dose (300–4000 Gy). Two TL glows, a small peak at 424 K and stronger peak at 597 K are observed. TL response of M–CaO is 2.67 times higher than F–CaO sample. TL kinetic parameters are calculated by computerized curve deconvolution analysis (CCDA) and discussed. - Highlights: • Calcium oxide powders have been synthesized using chicken egg shells as raw material. • Crystallite size was found to be 45–52 nm. • CaO derived from eggshells shows good thermoluminescence TL response. • TL response of the M–CaO is 2.67 times higher than the F–CaO sample.

Adjustment model of thermoluminescence experimental data

International Nuclear Information System (INIS)

Moreno y Moreno, A.; Moreno B, A.

2002-01-01

This model adjusts the experimental results for thermoluminescence according to the equation: I (T) = I (a i * exp (-1/b i * (T-C i )) where: a i , b i , c i are the i-Th peak adjusted to a gaussian curve. The adjustments of the curve can be operated manual or analytically using the macro function and the solver.xla complement installed previously in the computational system. In this work it is shown: 1. The information of experimental data from a LiF curve obtained from the Physics Institute of UNAM which the data adjustment model is operated in the macro type. 2. A LiF curve of four peaks obtained from Harshaw information simulated in Microsoft Excel, discussed in previous works, as a reference not in macro. (Author)

Ultraviolet dosimetry using thermoluminescent phosphors - an update

International Nuclear Information System (INIS)

Nagpal, J.S.

1998-04-01

Intrinsic response of various thermoluminescent (TL) materials such as CaSO 4 (Dy, Eu, Mn, Sm, Tb, or Tm), LiF (Mg, Cu, P), Mg 2 SiO 4 :Tb, CaF 2 :Dy, CaF 2 :Tb, ThO 2 :Tb and Al 2 O 3 (Si, Ti); cathodoluminescent phosphors Y 3 Al 5 O 12 :Ce, Y 3 Al 5 O 12 :Tb and Y(V,P)O 4 :Eu; and fluorescent lamp phosphors calcium halophosphate (Mn,Sb) and Ce Mg aluminate (Eu, Tb) to ultraviolet (UV) radiations has been studied. Intrinsic TL response of most of the phosphors is rate (radiant flux) dependent. For the first time, UV response of the materials is reported for a fixed total radiant energy (total UV dose), at a single radiant flux (260 μW.cm -2 ), for an appropriate comparison. A wide range of UV sensitivity is observed. Studies conducted using UV radiation from two unfiltered low pressure mercury lamps show significant differences in glow curves, as compared to those obtained with nearly monochromatic UV radiations. Photons of wavelength 365 nm induce bleaching of TL induced by 254 nm photons, in most of the materials. Sequential/tandem exposures to 254 nm and 365 nm photons have yielded new but alarming results in CaF 2 :Tb. Preferential induction and bleaching of specific TL glow peaks by 365 nm and 254 nm photons are interesting characteristics discovered in CaSO 4 :Eu. Photoluminescence studies of Tb 3+ and Eu 3+ activated phosphors have augmented the inferences drawn from the bleaching effects produced by 365 nm photons. Earlier work carried out on phototransferred thermoluminescence of CaSO 4 :Dy-teflon dosimeters, TLD-100, Mg 2 SiO 4 :Tb and Al 2 O 3 (Si,Ti) has also been reviewed. (author)

Study of 225 deg C thermoluminescent of quartz inclusions extracted from cementitious building materials

International Nuclear Information System (INIS)

Campos, Simara S.; Almeida, Geangela M. de; Souza, Suzana O.

2009-01-01

Incidents of excessive exposure of the population to ionizing radiation could result from a nuclear explosion, the direct exposure to a source theft or loss or an accidental exposure to a source without shielding, for example. During these incidents the victims seldom are using individual protection equipment used in the measurement and control of the doses that were exposed. One of the ways found to the doses assessment due to exposure to this type of accident is the retrospective dosimetry, which determines the excessive doses of radiation exposure, whether chronological or acute, using common materials available in the public domain. The methodology for the application of retrospective dosimetry for thermoluminescence in buildings previously burned, as bricks, it is already well established. Interest is now turning to the use of cementitious building materials such as mortar and concrete to enlarge the scope of application. This study aimed to examine some of these materials and techniques for their possible application in the doses assessment from an accidental irradiation by thermoluminescence. For this the peak about 225 deg C of natural quartz and it extracted of mortar and concrete was certain your stability for the plateau and storage tests, and also the dependence of your luminescent intensity with radiation dose. Presenting a life relatively tans compared enough to that of the accumulation of natural and long radiation sign for dosimetric applications, besides other favorable characteristics, the mortar presented evidence that is possible for retrospective dosimetry through thermoluminescence. (author)

Thermoluminescence studies having applications to geology and archaeometry

International Nuclear Information System (INIS)

Levy, P.N.

1978-01-01

Mineral thermoluminescence (TL) studies, undertaken as geophysics investigations, appear to have archaeometric applications. Measurements were made with equipment which records TL emission spectra at closely spaced temperatures. Carbonate rock containing lead-zinc deposits exhibit radiation induced TL against distance-from-ore patterns useful for mineral exploration and locating worked-out deposits. The feldspar albite has second-order TL kinetics, which can introduce dating errors. Heat induced changes in the albite TL emission spectra could be used as a paleotemperature indicator. Quartz remembers previous exposure to radiation, a property influencing TL intensity against dose curves but useful for uranium exploration

Development of BaSO4:Eu thermoluminescence phosphor

International Nuclear Information System (INIS)

Madhusoodanan, U.; Jose, M.T.; Lakshmanan, A.R.

1999-01-01

A highly sensitive thermoluminescence (TL) phosphor based on BaSO 4 :Eu was developed following the coprecipitation technique and firing in argon atmosphere at 1123 K. Photoluminescence studies confirm that firing in argon atmosphere instead of air increased the incorporation of Eu ions in 2+ valence state. At low γ-ray doses, its TL sensitivity is nearly 2 to 3 times higher than that of CaSO 4 :Dy phosphor. The other salient features of this BaSO 4 :Eu TL phosphor are a constant glow curve shape and a nearly linear γ-ray dose response

Thermoluminescence properties of graphene–nano ZnS composite

International Nuclear Information System (INIS)

Sharma, Geeta; Gosavi, S.W.

2014-01-01

This work describes the thermoluminescence (TL) of graphene oxide (GO), reduced graphene oxide (RGO) and graphene–nano ZnS composite. Graphene oxide was synthesized using Hummer's method and then reduced to graphene by hydrazine hydrate. G–ZnS was synthesized via in-situ reduction of graphene oxide (GO) and zinc nitrate [Zn(NO 3 ) 2 ] by sodium sulfide (Na 2 S). The structures of samples were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). XRD pattern confirmed the formation of graphene oxide, reduced graphene oxide and G–ZnS lattice. The p-XRD spectrum of G–ZnS shows peaks of ZnS superimposed on those of graphene and the particle size of ZnS in the complex is less than 10 nm. Ultra thin graphene and graphene oxide sheets with size ranging between tens to several hundreds of square nanometers are observed in TEM images. The TEM micrographs of G–ZnS show that ZnS particles are embedded in graphene sheets and the average particle size of ZnS particles in the composite is less than 10 nm. Samples of RGO, GO and G–ZnS were exposed to different doses of γ-rays in the range of 1 Gy to 50 kGy. The reduced graphene oxide (RGO) did not show any thermoluminescence emission. The thermoluminescence glow curve of GO has a single broad peak whose peak position varied between 500 and 550 K with an absorbed dose increasing from 1 Gy to 5000 Gy. GO shows most intense TL peak, positioned at 523.6 K for a dose of 10 kGy. The glow curves of G–ZnS over the entire range of irradiation have single peak positioned between 492 and 527 K with variation in dose from 1 Gy to 50 kGy. G–ZnS shows the most intense TL glow curve for a dose of 50 kGy. The TL response curve of G–ZnS is found to be linear over a larger dose range from 1 Gy to 50 kGy whereas the response curve of GO shows linearity only at low doses up to 100 Gy. -- Highlights: • Graphene oxide, reduced graphene oxide and graphene–nano ZnS were synthesized. • TL of

Correlation between the thermoluminescence and the F centre thermal stability in KBr, KI, NaCl and NaF irradiated at room temperature

International Nuclear Information System (INIS)

Mariani, D. F.

1977-01-01

Over the years several models have been proposed to explain the thermoluminescence in irradiated alkali halides. To verify these models, the thermoluminescence and the thermal stability of the F centres in KBr, K l, NaCl and NaF single crystals irradiated at room temperature with x or gamma rays have been studied. It has been concluded that both phenomena, the thermoluminescence and the F centre thermal stability are two different aspects of the same basic phenomenon, i.e. the recombination of mobile interstitials thermally released from traps with F centres (Ausin V. and Alvarez Rivas J.L. 1972). It has been found in some cases, that the H centres also play the role of recombination centres for interstitials. (Author) 42 refs

Desenvolvimento humano: contribuições da psicologia moral

Directory of Open Access Journals (Sweden)

Yves de La Taille

2007-03-01

Full Text Available Procuramos avaliar as contribuições do conhecimento acumulado pela Psicologia Moral para a compreensão do desenvolvimento humano, para sustentar a tese segundo a qual a fonte energética do dever moral precisa ser procurada não só em sentimentos exclusivamente morais, mas também em sentimentos que desempenham um papel para o próprio desenvolvimento humano no seu conjunto. Três são os passos da análise deste artigo. Em primeiro lugar, verifi car se há possibilidade de articulação entre teorias psicológicas que enfatizam a dimensão afetiva da moralidade (Freud e Durkheim e outras que enfatizam a dimensão intelectual (Piaget e Kohlberg. Em segundo lugar, uma vez constatada a impossibilidade dessa articulação, sustentar que o sentimento de vergonha, presente na moralidade mas também em outras dimensões do desenvolvimento humano, é condição necessária ao sentimento de obrigatoriedade. Finalmente, analisar se tal sentimento é passível de ser evocado como fonte energética essencial nas abordagens que enfatizam a dimensão intelectual da moralidade.

Recent advances in thermoluminescence dating

International Nuclear Information System (INIS)

Aitken, M.J.

1984-01-01

Initially the application of thermoluminescent dating was to ancient pottery and other baked clay, the detection of forgeries in art ceramics having a particularly powerful impact. In recent years there has been a growing extension of TL into non-pottery materials. Heated flints from paleolithic fire-places is one application. Another is in the dating of igneous rocks from recent volcanic events; formerly this had been impossible on account of the malign phenomenon of non-thermal ('anomalous') fading exhibited by volcanic minerals but this is now being circumvented by utilising TL in the 600 0 C region of the glow curve. TL dating has also been extended to unburnt calcite, one application being stalagmitic floors in paleolithic caves. Another recent development is the use of TL for dating aeolian sediment and some types of waterborne sediment. These developments give prospect of establishing a TL-based chronology, both for archaeology and quaternary research, extending back well beyond the range of radiocarbon, perhaps reaching a million years ago. (author)

O desenvolvimento econômico da Venezuela, 1950/2006

OpenAIRE

Romina Batista de Lucena de Souza

2008-01-01

O objetivo desta tese é avaliar a contribuição do petróleo no desenvolvimento econômico da Venezuela, entre 1950/2006. Investiga-se por que uma economia rica em petróleo ainda não conseguiu industrializar-se. Seguindo os diferentes períodos governamentais, examinam-se a contribuição das políticas macroeconômicas sobre o desenvolvimento e a questão da doença holandesa e do capitalismo rentístico. Segundo a teoria da base econômica, as regiões crescem em torno de uma base exportadora, exercendo...

Planos diretores: o caminho para o desenvolvimento sustentável das cidades

Directory of Open Access Journals (Sweden)

Alexsandro da Miranda

2013-11-01

Full Text Available Os Planos Diretores efetivam a existência de uma legislação geral estabelecendo as normas necessárias à implementação de políticas urbanas, previstas na Constituição Federal e no Estatuto da Cidade (Lei Federal 10.257/2001 e que em seu foco principal está o desenvolvimento e a expansão urbana.  Assim, o presente artigo aborda uma breve discussão teórica do tema, suas problemáticas e contextualizações na perspectiva de fundamentá-las à luz das teorias existentes. Três principais diretrizes devem ser destacadas: o desenvolvimento sustentável, a gestão democrática da cidade e o planejamento do desenvolvimento das cidades, onde os municípios, devem, portanto, utilizar as diretrizes e instrumentos do Estatuto da Cidade com o objetivo de estabelecer as regras que propiciem o pleno desenvolvimento econômico, social, ambiental e sustentável, com vistas a garantir o direito à cidade para todos os que nela vivem.

Desenvolvimento econômico, desigualdade e saúde Economic development, inequality, and health

Directory of Open Access Journals (Sweden)

Pedro Reginaldo Prata

1994-09-01

Full Text Available O autor se refere a dimensão socioeconômica, individual e coletiva do fenômeno saúde-doença. Refere-se também ao fato das populações estarem sobre a influência desigual de fatores de risco e de proteção à saúde. Discute as desigualdades no desenvolvimento e a relação entre desenvolvimento, riqueza, saúde e justiça social. Questiona as teorias de desenvolvimento econômico, diferenciando desenvolvimento de crescimento. Cunha os conceitos de armadilha do desenvolvimento e refugiados sociais. Define uma comunidade saudável. Propõe a necessidade de mudança no modelo de desenvolvimento. Baliza o papel e as limitações do setor saúde no que diz respeito a iniqüidade social.The author refers to the social, economic, individual, and collective dimensions of the relationship between health and disease. He considers that individuals and populations are not equally exposed to protective and risk factors. He highlights the uneven development between nations and Brazilian regions, and communities, as well as discussing the relationship between development, wealth, health, and social justice. The article analyzes development theories and makes a distinction between economic development and growth. The concepts of development trap and social refugees are coined. The author defines a healthy community, points to the need for a shift in the current development model, and delineates the health sector's role and limitations in dealing with social inequality.

Determination of the kinetic parameters of BeO thermoluminescent samples using different methods

Energy Technology Data Exchange (ETDEWEB)

Algarve, Fábio J.; Caldas, Linda V.E., E-mail: fjalgarve@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

The objective of this work was to determine the kinetic parameters of BeO thermoluminescent (TL) samples. The knowledge of the kinetic parameters is important for the general description of the physical characteristics of a thermoluminescent material. Using a linear heating rate of 5K/s{sup -1}, the BeO peak temperatures obtained were (474.7 ± 1.2) K and (620.5 ± 1.2) K, respectively, for the first and second TL peaks. The peak shape and the glow curve area measurement methods and the Urbach formula have been used for the trap parameter determination. A kinetic order of about two was determined for the first peak, whereas the second peak followed the first-order kinetics according to the geometrical factor. The energy activation values obtained using different kinds of measurements are in good agreement, including the Kitis method for deconvolution of the glow curve. Furthermore the results agree with those presented by other authors. (author)

Thermoluminescent properties of nanocrystalline ZnTe thin films: Structural and morphological studies

Science.gov (United States)

Rajpal, Shashikant; Kumar, S. R.

2018-04-01

Zinc Telluride (ZnTe) is a binary II-VI direct band gap semiconducting material with cubic structure and having potential applications in different opto-electronic devices. Here we investigated the effects of annealing on the thermoluminescence (TL) of ZnTe thin films. A nanocrystalline ZnTe thin film was successfully electrodeposited on nickel substrate and the effect of annealing on structural, morphological, and optical properties were studied. The TL emission spectrum of as deposited sample is weakly emissive in UV region at ∼328 nm. The variation in the annealing temperature results into sharp increase in emission intensity at ∼328 nm along with appearance of a new peak at ∼437 nm in visible region. Thus, the deposited nanocrystalline ZnTe thin films exhibited excellent thermoluminescent properties upon annealing. Furthermore, the influence of annealing (annealed at 400 °C) on the solid state of ZnTe were also studied by XRD, SEM, EDS, AFM. It is observed that ZnTe thin film annealed at 400 °C after deposition provide a smooth and flat texture suited for optoelectronic applications.

Semiconductor scintillator detector for gamma radiation

International Nuclear Information System (INIS)

Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S.

2015-01-01

Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

Thermoluminescent dosimetry of new phosphors of Zn O exposed to beta radiation; Dosimetria termoluminiscente de nuevos fosforos de ZnO expuestos a radiacion beta

Energy Technology Data Exchange (ETDEWEB)

Cruz V, C.; Burruel I, S.E.; Grijalva M, H. [UNISON, A.P. 130, Hermosillo, Sonora (Mexico); Barboza F, M.; Bernal, R. [CIF, UNISON, A.P. 5-088, Hermosillo, Sonora (Mexico)

2004-07-01

In this work, we report the thermoluminescence dosimetry of a new Zn O phosphor obtained by annealing of Zn S powder precipitated when Zn S films were grown by employing a CBD method. The collected Zn S powder was pressed in a die to form pellets which were subjected to different thermal treatments under air atmosphere. X-ray diffraction (XRD) patterns and energy-dispersive X-ray Spectrometry (EDS) analyses confirmed the transformation of Zn S to Zn O. The phosphors thus obtained were exposed to high doses of beta radiation and their thermoluminescent dosimetry show that these new phosphors are materials suitable to be used in high dose thermoluminescence dosimetry. (Author)

Crystal scintillators for use in check-light source for thermoluminescent systems

Science.gov (United States)

Nagpal, J. S.; Sabharwal, S. C.; Chougaonkar, M. P.; Godbole, S. V.

1999-08-01

Beta ( 63Ni, Emax 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi 4Ge 3O 12 and CdWO 4 has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported.

Dosimetric characteristics of Li2B4O7:Cu,Ag,P solid TL detectors

International Nuclear Information System (INIS)

Proki, M.

2002-01-01

The main dosimetric characteristics are presented of newly prepared tissue-equivalent, highly sensitive thermoluminescent detector, Li 2 B 4 O 7 :Cu,Ag,P in the form of sintered pellets, developed at the Institute of Nuclear Sciences, Vin a . As a result of an advancement in the preparation procedure by the sensitising of basic copper activated lithium borate TL material, significant improvement in the TL sensitivity of Li 2 B 4 O 7 :Cu,Ag,P was gained. The glow curve of Li 2 B 4 O 7 :Cu,Ag,P consists of well defined main dosimetric peak situated at about 185-190 deg. C with the TL sensitivity which is about four to five times higher than that of LiF:Mg,Ti (TLD-100). From the experimental results a very wide linear dose response range, up to 10 3 Gy is evident. Dosimetric characteristics make sintered solid Li 2 B 4 O 7 :Cu,Ag,P TL detectors very promising for different dosimetry applications particularly in medical dosimetry and also for individual monitoring. (author)

Thermoluminescence, luminescence optically stimulated and creation of defects in alkaline halogenides contaminated with Europium; Termoluminiscencia, luminiscencia opticamente estimulada y creacion de defectos en halogenuros alcalinos contaminados con Europio

Energy Technology Data Exchange (ETDEWEB)

Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

1999-07-01

The alkaline halogenides have been subject matter of investigations related with the search of sensor materials for X-ray bidimensional images or optical memories. The understanding of the damage formation processes generated by ionizing and non-ionizing radiations is important for the correct design of devices that working as detectors and dosemeters of both type of radiations. In this work we present the investigation results related with the defects produced by the ionizing radiation type X and ultraviolet light in the range of 200-360 nm in crystals of KCl: Eu{sup 2+} and KBr:Eu{sup 2+}. It is examined the thermoluminescence and luminescence spectra with the purpose of identifying the exciton processes, owing to the excitation of the halogenide ions in which the primary defects correspond to the F and H centers. It has been found that the 400-600 nm emission is associated with the luminescence type that in his turn can be associated with autotrapped excitons perturbed by the impurity. On the other hand, it is examined the emission spectra of the luminescence optically stimulated in crystals of KBr: Eu{sup 2+} and KCl: Eu{sup 2+} finding too that such materials would be used as optical memories susceptible of to store information, and through of photostimulation to read this. It was determined that the F centers participate in the luminescence optically stimulated in these crystals, as well as too in the recombination processes responsible by the thermoluminescent emission. (Author)

DESENVOLVIMENTO DE RECURSOS DIDÁCTICOS INFORMATIZADOS NO ÂMBITO DA EDUCAÇÃO PARA O DESENVOLVIMENTO SUSTENTÁVEL. O EXEMPLO DO COURSEWARE SeRe

Directory of Open Access Journals (Sweden)

Patrícia Sá

2010-02-01

Full Text Available A falta de recursos didácticos informatizados de qualidade para o 1º e 2º Ciclos do Ensino Básico (1º/2º CEB, concebidos no âmbito da Educação para o Desenvolvimento Sustentável (EDS, numa perspectiva de Ensino por Pesquisa, determinou a organização de uma equipa multidisciplinar para o desenvolvimento do «Courseware Sere - O Ser Humano e os Recursos Naturais». Ajustando alguns princípios de desenvolvimento de software, particularmente de Design Centrado noUtilizador (DCU, o trabalho da equipa multidisciplinar, constituída por elementos com diversas competências (ao nível da Didáctica das Ciências, da Tecnologia Educativa, de Design e de Programação, centrou-se no desenvolvimento de um recurso didáctico informatizado que integra várias tipologias de software, nomeadamente simulações e visualizações, com as actividades didácticas. A orientação do recurso, as temáticas propostas e as metodologias e estratégias de exploração privilegiadas fundamentam-se: i na identificação das orientações nacionais e internacionais da EDS; ii na identificação das necessidades e interesses dos professores quanto à implementação de actividades com orientação EDS (Sá, 2008; Sá e Martins, 2007, iii no paradigma de ensino por competências (Cachapuz, Sá-Chaves e Paixão, 2004 e iv no recurso a um design interactivo centrado no utilizador (Costa, Loureiro, Reis, Sá, Guerra e Vieira, 2009; Guerra, 2007. Neste artigo faz-se uma apresentação do processo de desenvolvimento do recurso didáctico, das temáticas propostas e dasmetodologias e estratégias de exploração perspectivadas pelos autores do recurso.

Thermoluminescence analysis for detection of irradiated food - luminescence characteristics of minerals for different types of radiation and radiation doses

International Nuclear Information System (INIS)

Soika, C.; Delincée, H.

2000-01-01

Federal Research Centre for Nutrition, Institute of Nutritional Physiology, Haid-und-Neu-Straße 9, 76131 Karlsruhe (Germany) Thermoluminescence analysis is used to detect radiation processing of foods which are contaminated with sand or dust. Silicate minerals are isolated, their radiation-induced luminescence is measured and compared to the thermoluminescence from a second measurement after exposure to a dexned radiation dose (normalization). In the present study, the mineral mixture *sand+ and its main components feldspar and quartz were investigated for their thermoluminescence behaviour using different types of radiation, in order to determine adequate radiation sources for the purpose of normalization. The material was irradiated with types of ionizing radiation commonly used for commercial food irradiation, i.e. accelerated electrons with beam energies of 5 MeV as well as 10 MeV, and 60 Co--rays. After thermoluminescence measurements, samples were re-irradiated using either accelerated electrons with beam energies of 2 MeV, 5 MeV or 10 MeV, or 60 Co--rays, 90 Sr--rays or ultraviolet rays (200}280 nm). Evaluation of the xrst and corresponding second glow curve revealed that their shapes depend on the type of minerals in the mixture. The second radiation treatment (normalization) is satisfactory when accelerated electrons (2, 5 and 10 MeV) as well as 60 Co--rays and 90 Sr--rays are employed. Normalization with ultraviolet rays, however, has only a limited range of use

Characterization of the personal thermoluminescent dosemeter of LiF: Mg, Ti + Ptfe

International Nuclear Information System (INIS)

Azorin N, J.; Gutierrez C, A.; Gonzalez M, P.

1991-01-01

The objective of this work is to characterize the thermoluminescent dosemeters taken place in the laboratory in form of pellets of LiF: Mg, Ti + Ptfe like personal dosemeters, subjecting them to the operation tests proposed by the international standards and comparing them with the TLD-100, the Tl dosemeter more used at the moment for personal dosimetry

Thermoluminescence property of nano scale Al{sub 2}O{sub 3}: C by combustion method

Energy Technology Data Exchange (ETDEWEB)

Bharthasaradhi, R.; Nehru, L. C. [Department of Medical Physics, School of Physics, Bharathidasan University, Tiruchirappalli-620 024, Tamilnadu (India)

2016-05-23

In this study, thermoluminescence dosimetry material of carbon doped aluminium oxide by combustion method using Aluminium nitrate and Glycine. The Structure of the prepared Sample was carried out by XRD. The sample was nano crystalline in nature. Having hexagonal structure with unit cell parameters a=4.75Å, C=12.99Å. The surface morphology of the prepared nanopowder was carried out through (SEM). The morphology of the prepared sample is platelet structure and functional group analysis carried out through FT-IR Spectrum. The prepared sample was irradiated through γ-ray CO{sup 60} (100 Gy) was used as γ-ray source. The thermoluminescence glow curve of the irradiated sample showed an isolated peak at around 200°C. The result suggest the prepared nanopowder is suitable for medical radiation dosimetry.

A mesoeconomia do desenvolvimento econômico: o papel das instituições

Directory of Open Access Journals (Sweden)

Huáscar Pessali

2011-01-01

Full Text Available O desenvolvimento econômico depende das instituições e as instituições, ao mesmo tempo, são uma medida do desenvolvimento econômico. Assim, correlação e causalidade se confundem num processo cumulativo e circular - uma espiral de mudanças que condiciona a ampliação das liberdades dos indivíduos. A contribuição pretendida por este ensaio é reunir e propor uma organização de várias idéias dispersas no tema "instituições e desenvolvimento econômico". Nossa releitura adiciona um breve exemplo da relação entre mercados, firmas e estado no âmbito do desenvolvimento. Isto permite defender o retorno a uma análise econômica que não se limite às falhas de mercado, mas que encare a responsabilidade de lidar com um emaranhado mais complexo de interações.

O TRABALHO COMO ATIVIDADE PRINCIPAL NO DESENVOLVIMENTO PSÍQUICO DO INDIVÍDUO ADULTO

Directory of Open Access Journals (Sweden)

Camila Fernanda Moro Rios

2017-12-01

Full Text Available Este artigo visa analisar, por meio da revisão teórica de autores clássicos e contemporâneos da psicologia histórico-cultural, o trabalho como atividade principal na vida adulta, isto é, como a atividade que orienta as principais mudanças no psiquismo humano e na personalidade nessa idade. Para tanto, abstrai e generaliza elementos constantes nos estudos sobre periodização do desenvolvimento psíquico humano. Por um lado, identifica os conteúdos e processos psicológicos que, produzidos pelo trabalho, evidenciam sua relevância para o desenvolvimento do indivíduo adulto. Por outro, aborda os processos de alienação inerentes à sociedade capitalista, que alienam o trabalho como atividade principal. Assim, o trabalho se apresenta, dialeticamente, como atividade humanizadora e alienada. Entende-se que este estudo contribui para o avanço teórico-metodológico da psicologia histórico-cultural por abordar a questão do trabalho como atividade principal, uma discussão que se encontra ainda incipiente e pouco sistematizada. Além disso, supera o enfoque dos estudos sobre o desenvolvimento centrados na infância e reitera o rompimento com a perspectiva maturacionista de que a vida adulta é um período de estagnação do desenvolvimento. Pela análise do trabalho como atividade principal conclui-se que o desenvolvimento psicológico, produzido na vida adulta, se expressa, principalmente, por uma série de aquisições de habilidades e capacidades, pelo exercício da criatividade, por uma complexa reestruturação da esfera afetivo-motivacional da personalidade, pelo desenvolvimento da autoconsciência e pelo movimento dialético da consciência de classe, que tensiona a contradição entre o polo humanizador e o polo alienado/alienante do trabalho numa sociedade que limita e empobrece esse mesmo desenvolvimento.

Calibration of SSNDT detectors for radon measurements

International Nuclear Information System (INIS)

Takahashi, Laura C.; Santos, Talita O.; Pinheiro, Rose Mary M.; Rocha, Zildete

2017-01-01

The methods and instrumentation used to measure the concentration of radon need to be calibrated to obtain accurate results. The Nuclear Track Detector is considered the main method of analysis of radon research. Thus, the Natural Radioactivity Laboratory of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG, Brazil) uses the detector CR-39 (Landauer) to measure the concentration of radon in homes, workplaces, underground mines, soils and in environment. Epidemiological studies reveal the strong relationship between lung cancer and radon exposure. Therefore, it is important to monitor this gas and its progeny in order to assess the radiological risk. The alpha particles emitted by radon and its progeny leave traces on CR-39 due to Coulombian interactions with the atoms of the material. The liquid density of traces is converted to radon concentration by means of a calibration factor obtained in calibrated systems. This work aims to determine the LRN / CDTN calibration factor. To do so, the CR-39 detectors were placed inside the calibration chambers, along with two AlphaGUARD (Saphymo GmbH) detectors and Ra-266 sources with activities of 3,379 kBq or 0.483 kBq, referenced by NIST. From this, six levels of exposure were obtained, which were: 44 kBq.d.m 3 , 4 kBq.d.m 3 , 3 kBq.d.m 3 , 15 kBq.d.m 3 , 30 kBq.d.m 3 , 26 kBq.d.m 3 . The conversion factor between the liquid density of traces and the total exposure time obtained was K = 52.028 ± 0.752 [(trace density.cm -2 ) / (kBq.d.m -3 )]. After the determination of the conversion factor, it was used to measure the concentration of radon in underground mines, obtaining concentration results between 122 ± 24 and 7384 ± 517 kBq.m -3

On the set up of a thermoluminescent dosimetric system

International Nuclear Information System (INIS)

Furetta, C.

2000-01-01

In this work are treated the following features: Introduction to the thermoluminescent dosimetric systems, their prerequisites, Initialisation procedure, Batch homogeneity, Procedure for batch homogeneity (IEC), Reference and field dosimeters, Thermal treatments and its general considerations, as well as its initialisation treatment, erasing treatment or standard annealing (also called pre-irradiation annealing), post-irradiation or pre-readout annealing. Also is presented the performance of the annealing study, with its suggested procedures such as: a first and second procedures. Finally, it is showed about experimental data of the annealing treatments and its diagrams. (Author)

Use of thermoluminescent dosimetry in gamma radiation fields studies

International Nuclear Information System (INIS)

Carron, W.

1987-01-01

The depth-dose curves for gamma rays in material of interest to agronomy were obtained using lithium fluoride thermoluminescent dosimeters. The dose conversion factors for LiF were determined from curves of the absorved dose versus depth in water, wood and soil. Mathematics equations were chosen to best fit these curves. In the view of the results we came to the conclusion that in the studied materials the absorved radiation dose presents a great variation to the depth and could be correlated through of the exponential regression. (author)

Thermoluminescent determination of prehistoric heat treatment of chert artifacts

International Nuclear Information System (INIS)

Melcher, C.L.; Zimmerman, D.W.

1977-01-01

In recent years archeologists have become interested in the extent to which prehistoric peoples heat-treated chert prior to shaping it into tools. Thermoluminescent determination of the radiation dose accumulated by an artifact since it was formed or last heated provides a simple, reliable test for such heat treatment. This test can be applied to single artifacts without the need for raw source material for comparison. Results on 25 artifacts from four sites indicate that, for many chert sources, color and luster are not useful indicators of heat treatment by prehistoric peoples

Thermoluminescence in KBr:D electron irradiated at room temperature

International Nuclear Information System (INIS)

Paredes Campoy, J.C.; Lopez Carranza, E.

1991-07-01

The thermoluminescence of KBr:D samples electron irradiated at room temperature after thermal annealing at 673 K for 1 hour have been studied in the temperature range 360-730 K. The experimental TL-curve was discomposed by computer analysis in seven overlapping TL peaks, giving for them the order of the kinetics of thermal stimulation, the activation energy, the frequency factor, the relative values of the electronic concentration in traps at the initial heating temperature and the temperature at the maximum of the peak. (author). 18 refs, 1 fig., 3 tabs

Thermoluminescence of laterites: applicability in dating

International Nuclear Information System (INIS)

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

1985-01-01

The northward drift of the Indian subcontinent during the past geological periods brought it under the spell of humid tropical climate in post-mesozoic times which initiated chemical weathering processes (lateritization) of the ancient crustal rocks leading to neomineralization. In the present study, thermoluminescence (TL) of these 'later-formed minerals' has been used to date laterites from a number of localities in India. While the TL emission of most of the laterite samples was poor, three from Kerala, Tamil Nadu and Karnataka states, each derived from mineralogically dissimilar parent rock, yielded measurable TL and provided dates in the range of 2 to 3.6 x 10 5 yr. It is suggested that TL dating can be a promising tool for such samples, and especially those with low alpha activity (U, Th at sub-ppm levels). (author)

Thermoluminescence of laterites: applicability in dating

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

The northward drift of the Indian subcontinent during the past geological periods brought it under the spell of humid tropical climate in post-mesozoic times which initiated chemical weathering processes (lateritization) of the ancient crustal rocks leading to neomineralization. In the present study, thermoluminescence (TL) of these 'later-formed minerals' has been used to date laterites from a number of localities in India. While the TL emission of most of the laterite samples was poor, three from Kerala, Tamil Nadu and Karnataka states, each derived from mineralogically dissimilar parent rock, yielded measurable TL and provided dates in the range of 2 to 3.6 x 10/sup 5/ yr. It is suggested that TL dating can be a promising tool for such samples, and especially those with low alpha activity (U, Th at sub-ppm levels).

Theoretical Studies on the Physical and Environmental Factors Which Govern the Thermal Fading of Thermoluminescence Signal

International Nuclear Information System (INIS)

Rasheedy, M.S.; El-Sherif, M.A.; Hefni, M.A.

2008-01-01

Thermoluminescence solid-state detector is widely used to determine the dose in personnel and environmental monitoring for radiation protection purposes, for instance in the field of nuclear power production, medicine and research. However, thermal fading is a limiting factor for a long-term application, especially where temperature is changing significantly during the accumulation period. This paper studied the influence of temperature and duration of storage after irradiation on the thermal fading of the TL signal. Also, this paper discussed the dependence of the thermal fading on the trap parameters of TL glow peak. The most important parameters, which were considered here include the order of kinetics b, the depth of the trap level E (eV) and the frequency factor S (s-1). The dependence of the thermal fading on thermal stability parameters, namely trap depths and frequency factors for the glow peaks is discussed. The variation of the thermal fading as a function of the order of kinetics is demonstrated. In addition, this paper discussed the dependence of the thermal fading on the absorbed dose in case of first-, second- and general-order kinetics. The above-mentioned studies were arranged considering the models of first-, second- and general-order of kinetics

Thermal neutron detection by activation of CaSO4:Dy + KBr thermoluminescent phosphors

International Nuclear Information System (INIS)

Gordon, A.M.P.L.; Muccillo, R.

1979-01-01

Thermoluminescence (TL) studies to detect thermal neutrons were performed in cold-pressed CaSO 4 :0,1%Dy + KBr samples. The detection is based on the self-irradiation of the CaSO 4 :Dy TL phosphor by the Br isotopes activated by exposure to a mixed neutron-gamma field. (Author) [pt

The thermoluminescence and optically stimulated luminescence properties of Cr-doped alpha alumina transparent ceramics

International Nuclear Information System (INIS)

Liu, Qiang; Yang, Qiu Hong; Zhao, Guang Gen; Lu, Shen Zhou; Zhang, Hao Jia

2013-01-01

Highlights: •Polycrystalline Cr:α-Al 2 O 3 transparent ceramics were obtained with vacuum sintering method. •The influence of different concentration of Cr 2 O 3 on the thermoluminescence and optical stimulated luminescence properties of Cr:α-Al 2 O 3 transparent ceramics was studied. •It had a main peak at 503 K of very high intensity and linear concentration dependence up to high concentration. •It showed so interesting results with high TL sensitivity and high stability of OSL signal that Cr:α-Al 2 O 3 transparent ceramics might be a promising material in TL dosimetry and replace Cr:α-Al 2 O 3 crystals. -- Abstract: Polycrystalline Cr:α-Al 2 O 3 transparent ceramics were fabricated by conventional solid-state processing under vacuum condition. The SEM microstructure photographs of Cr:α-Al 2 O 3 transparent ceramics doped with different content of Cr 2 O 3 were investigated. The absorption, emission spectra, thermoluminescence and optical stimulated luminescence of Cr:α-Al 2 O 3 transparent ceramics were comparable to those of Cr:α-Al 2 O 3 crystals. The influence of different concentration of Cr 2 O 3 on the thermoluminescence and optical stimulated luminescence properties of Cr:α-Al 2 O 3 transparent ceramics was discussed. It showed so interesting results with high TL sensitivity and high stability of OSL signal that Cr:α-Al 2 O 3 transparent ceramics might be a promising material in TL dosimetry and replace Cr:α-Al 2 O 3 crystals

Thermoluminescence dating studies at Gua Tok Long, Gunung Senyum, Temerloh, Pahang

International Nuclear Information System (INIS)

Rosli Mahat

2004-01-01

The paper discussed the thermoluminescence dating studies carried-out by the researchers from Physics Department, University Malaya. One of these dating studies was done at a cave of the mountain, Gua Tok Long, Gunung Senyum, Temerloh, Pahang, Malaysia. The result presents a straight line of Age vs Height graph. It shows the particulates and dirts of the cave atmosphere landed at constant rate on the cave floor without an erosion

Thermoluminescence properties of zinc oxide obtained by solution combustion synthesis

Energy Technology Data Exchange (ETDEWEB)

Orante B, V. R.; Escobar O, F. M.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R., E-mail: victor.orante@polimeros.uson.mx [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

2014-08-15

High-dose thermoluminescence dosimetry properties of novel zinc oxide obtained by solution combustion synthesis in a glycine-nitrate process, with a non-stoichiometric value of the elemental stoichiometric coefficient (Φ{sub c}) are presented in this work. Zn O powder samples obtained were annealed afterwards at 900 grades C during 2 h in air. Sintered particles of sizes between ∼ 0.5 and ∼ 2 μm were obtained, according to scanning electron microscopy results. X-ray diffraction indicates the presence of the hexagonal phase of Zn O for the powder samples obtained, before and after thermal annealing, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima; one located at ∼ 149 grades C and another at ∼ 308 grades C, being the latter the dosimetric component of the curve. Dosimetric characterization of non-stoichiometric zinc oxide provided experimental evidence like asymptotic behavior of the Tl signal fading for times greater than 16 h between irradiation and the corresponding Tl readout, as well as the linear behaviour of the dose response without saturation in the dose interval studied (from 12.5 up to 400 Gy). Such characteristics place Zn O phosphors obtained in this work as a promising material for high-dose radiation dosimetry applications (e.g., radiotherapy and food industry). (author)

Effect of thermal decomposition of hydroxyapatite on the thermoluminescent response

International Nuclear Information System (INIS)

Sandoval C, K. J.; Zarate M, J.; Lemus R, J.; Rivera M, T.

2014-08-01

In this work, a study on the thermoluminescence (Tl) induced by gamma radiation in synthetic hydroxyapatite (Hap) annealed at different temperatures obtained by the precipitation method is presented. Synthesis of hydroxyapatite Hap was carried out starting from inorganic precursors [Ca(NO 3 ) 2 ·4H 2 O and (NH 4 ) 2 HPO 4 ]. The precipitate was filtered, washed, dried and then the powder was calcined at different temperatures until the Hap decomposition. The structural and morphological characterization was carried out using both X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques. Thermoluminescent (Tl) properties of Hap powders were irradiated at different gamma radiation doses. According to X ray diffraction patterns, the tricalcium diphosphate phase (Tcp) appear when the Hap was calcined at 900 grades C. Tl glow curve showed two peaks located at around 200 and 300 grades C, respectively. Tl response as a function of gamma radiation dose was in a wide range from 25 to 100 Gy. The fading of the Tl response at 134 days after irradiation was measured. Experimental results showed that the synthetic hydroxyapatite obtained by precipitation technique may have dosimetric applications when is annealed at temperature of 900 grades C, where the Tcp phase appears and contributes to Tl response, which opens the possibility of using this biomaterials in the area of dosimetry, as they are generally used for biomedical implants. (author)

A preliminary approach to identify irradiated foods by thermoluminescence measurements

International Nuclear Information System (INIS)

Shin, Choonshik; Kim, Hyoung-Ook; Lim, Yoongho

2012-01-01

Thermoluminescence (TL) is one of the physical methods for the identification of irradiated foods. Among the currently developed methods, TL is the most widely used method for the identification of irradiated foods. However, in order to use this method, silicate minerals should be isolated from food samples. The process for the isolation of silicate minerals is time consuming and laborious. In this work, we have investigated the applicability of the TL method using iron-containing minerals instead of silicate minerals. In the TL analyses of dried spices, TL glow curves of iron-containing minerals showed maximum temperatures between 150 and 250 °C which were the same as those of silicate minerals. The process for the mineral separation of the proposed method is simple, fast, easy, and reliable. Moreover, the analysis results including TL ratio have not shown significant differences compared with the silicate minerals method. As a result, the TL measurements using the iron-containing minerals could be an excellent method for the identification of the irradiated foods, including dried spices. - Highlights: ► A thermoluminescence method using iron-containing minerals is proposed. ► Current method using silicate minerals is time consuming and laborious. ► However, the proposed method is simple, fast, easy, and reliable. ► Analysis results are similar to those of the silicate minerals method.

Thermoluminescence properties of zinc oxide obtained by solution combustion synthesis

International Nuclear Information System (INIS)

Orante B, V. R.; Escobar O, F. M.; Cruz V, C.; Bernal, R.

2014-08-01

High-dose thermoluminescence dosimetry properties of novel zinc oxide obtained by solution combustion synthesis in a glycine-nitrate process, with a non-stoichiometric value of the elemental stoichiometric coefficient (Φ c ) are presented in this work. Zn O powder samples obtained were annealed afterwards at 900 grades C during 2 h in air. Sintered particles of sizes between ∼ 0.5 and ∼ 2 μm were obtained, according to scanning electron microscopy results. X-ray diffraction indicates the presence of the hexagonal phase of Zn O for the powder samples obtained, before and after thermal annealing, without any remaining nitrate peaks observed. Thermoluminescence glow curves of Zn O obtained after being exposed to beta radiation consists of two maxima; one located at ∼ 149 grades C and another at ∼ 308 grades C, being the latter the dosimetric component of the curve. Dosimetric characterization of non-stoichiometric zinc oxide provided experimental evidence like asymptotic behavior of the Tl signal fading for times greater than 16 h between irradiation and the corresponding Tl readout, as well as the linear behaviour of the dose response without saturation in the dose interval studied (from 12.5 up to 400 Gy). Such characteristics place Zn O phosphors obtained in this work as a promising material for high-dose radiation dosimetry applications (e.g., radiotherapy and food industry). (author)

Environmental radiation measurements using lithium fluoride thermoluminescence dosemeters

Energy Technology Data Exchange (ETDEWEB)

Driscoll, C.M.H.; Green, B.M.R.; McKinlay, A.F.; Richards, D.J. (National Radiological Protection Board, Harwell (UK))

1984-01-01

The National Radiological Protection Board is involved in a large scale environmental survey of radiation levels in homes throughout the United Kingdom. Passive radon and gamma ray dosemeters are posted to a representative sample of households. Lithium fluoride thermoluminescence dosemeters are used to assess natural gamma radiation and are left in the measurement location for a period of six months before being returned to the Board for processing. As a preliminary to the national survey, the Board has been engaged on several limited surveys in regions of igneous and sedimentary geology. Experience gained in these limited surveys and from standardisation studies using environmental dosemeters are reported.

Thermoluminescent characteristics of ZrO2:Nd films

International Nuclear Information System (INIS)

Vera B, G.; Rivera M, T.; Azorin N, J.; Falcony G, C.; Garcia H, M.; Martinez S, E.

2002-01-01

In this work it is exposed the obtained results after analysing the photo luminescent and thermoluminescent characteristics of activated zirconium oxide with neodymium (ZrO 2 :Nd) and its possible application in the UV radiation dosimetry. The realized experiments had as objective to study the characteristics such as the optimum thermal erased treatment, the influence of light on the response, the response depending on the wavelength, the fadeout of the information, the temperature effect, the response depending on the time and the recurring of the response. The results show that the ZrO 2 :Nd is a promising material to be used as Tl dosemeter for the UV radiation. (Author)

PTFE Additive and Re-annealing Effect on Thermoluminescence Response of CaSO4:Dy Derived from Co-precipitation Method

Science.gov (United States)

Nuraeni, Nunung; Dwi Septianto, Ricky; Iskandar, Ferry; Haryanto, Freddy; Waris, Abdul; Hiswara, Eri

2017-07-01

Effect of re-annealing treatment in thermoluminescence response of thermoluminescent dosimeter (TLD) CaSO4:Dy and CaSO4:Dy with PTFE (Polytetrafluoroethylene) addition was investigated. CaSO4:Dy was prepared by a co-precipitation method. The PTFE was added before re-annealing treatment which the mass ratio of CaSO4:Dy and PTFE was fixed to 2:3. The re-annealing treatments of the samples were done at temperature 700 °C for 1 hr. The obtained samples were characterized using a Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) to observe the molecule bonding in sample and crystal properties, respectively. From the experimental results, it was observed that the thermoluminescence intensity of CaSO4:Dy, CaSO4:Dy re-annealed at 700 °C, and CaSO4:Dy + PTFE re-annealed at 700 °C are 57.03, 75.15, and 1191.11 nC, respectively. The intensity of 700 °C-re-annealed CaSO4:Dy increased significantly after PTFE addition.

O coaching enquanto prática de desenvolvimento de recursos humanos

OpenAIRE

Soares, Luciana Rocha

2013-01-01

A presente investigação visa identificar os benefícios do coaching para o desenvolvimento de recursos humanos, procurando entender como esta prática contribui para o desenvolvimento de competências, para a melhoria de desempenhos e resultados organizacionais. Sendo uma pesquisa de natureza qualitativa, foram realizadas entrevistas semiestruturadas a 10 coaches profissionais, as quais foram submetidas a análise de conteúdo. Não representativos da população, os resultados obti...

Suitability of the thermoluminescence method for detection of irradiated foods

International Nuclear Information System (INIS)

Pinnioja, S.

1993-01-01

Irradiated foods can be detected by thermoluminescence (TL) of contaminating minerals. Altogether about 300 lots of herbs, spices, berries, mushrooms and seafood were studied by the TL method. Irradiated herbs and spices were easily differentiated from unirradiated ones two years after irradiation of a 10 kGy dose. The mineral composition of seafood was variable; and while calcite was suitable for the TL analysis, aragonite and smectite gave unreliable results. Control analyses during two years confirmed the reliability of TL method. (author)

Desenvolvimento Policêntrico na Europa : Uma reflexao critica sobre um conceito de politicas normativas

NARCIS (Netherlands)

Meijers, E.J.

Durante a última década, o desenvolvimento policêntrico tornou-se um conceito-chave no desenvolvimento territorial europeu. Em muitos aspectos, é um conceito difuso que significa diferentes coisas para diferentes pessoas em diferentes escalas espaciais. Neste artigo, analisamos as variadas

A computerized glow curve analysis (GCA) method for WinREMS thermoluminescent dosimeter data using MATLAB

International Nuclear Information System (INIS)

Harvey, John A.; Rodrigues, Miesher L.; Kearfott, Kimberlee J.

2011-01-01

A computerized glow curve analysis (GCA) program for handling of thermoluminescence data originating from WinREMS is presented. The MATLAB program fits the glow peaks using the first-order kinetics model. Tested materials are LiF:Mg,Ti, CaF 2 :Dy, CaF 2 :Tm, CaF 2 :Mn, LiF:Mg,Cu,P, and CaSO 4 :Dy, with most having an average figure of merit (FOM) of 1.3% or less, with CaSO 4 :Dy 2.2% or less. Output is a list of fit parameters, peak areas, and graphs for each fit, evaluating each glow curve in 1.5 s or less. - Highlights: → Robust algorithm for performing thermoluminescent dosimeter glow curve analysis. → Written in MATLAB so readily implemented on variety of computers. → Usage of figure of merit demonstrated for six different materials.

Dating by the method of thermoluminescence of a prehistoric campfire found in the archaeological site of Baixa do Umbuzeiro, RN, Brazil

International Nuclear Information System (INIS)

Azevedo, Renata L.; Santana, Sergio T.; Khoury, Helen J.; Sullasi, Henry L.; Borges, Fabio M.; Avila, Gabriela M.; Pessis, Anne-Marie

2011-01-01

In this work it was carried out the dating of a prehistoric campfire found in the archaeological site of Baixa do Umbuzeiro - RN, by the method of thermoluminescence (TL). To perform the dating, were collected five sediment samples from different parts of the campfire. The accumulated dose in these samples was obtained by the method of regenerative doses in which the natural TL intensity is compared with the TL intensity of doses supplied in artificial laboratory through a Co-60 source. The determination of the annual dose rate was performed by the determination of the levels of U, Th and K in the samples by gamma spectrometry with germanium hyper pure detector (GeHP). The five values found for accumulated dose were evaluated by the statistical test ANOVA, having been discarded one of these. The accumulated dose average is 12.5 ± 1.5 Gy and the annual dose rate is 3.31 ± 0.60 mGy/year. These values provided an age of about 3776 ± 821 years for the campfire of Baixa do Umbuzeiro. (author)

Thermal annealing of high dose radiation induced damage at room temperature in alkaline. Stored energy, thermoluminescence and coloration

International Nuclear Information System (INIS)

Delgado, L.

1980-01-01

The possible relation between stored energy, thermoluminescence and colour centre annealing in gamma and electron irradiated alkali halides is studied. Thermoluminescence occurs at temperature higher than the temperature at which the main stored energy peak appears. No stored energy release is detected in additively coloured KC1 samples. Plastic deformation and doping with Ca and Sr induce a stored energy spectrum different from the spectrum observed in pure and as cleaved samples, but the amount of stored energy does not change for a given irradiation dose.Capacity of alkali halides to store energy by irradiation increases as the cation size decreases. (Author) 51 refs

Radiation damage studies of mineral apatite, using fission tracks and thermoluminescence techniques

International Nuclear Information System (INIS)

Al-Khalifa, I.J.M.

1988-01-01

In a uranium (/thorium)-rich mineral sample which has not suffered a recent geological high-temperature excursion, the fossil fission track density (FFTD) will give a good indication of its natural radiation damage, provided that its U/Th ratio is known. From our studies of FFTD and thermoluminescence (TL) properties of several samples of apatite from different locations, and containing varying degrees of natural-radiation damage, an anti-correlation is observed between FFTD and TL sensitivity. It is also found that an anti-correlation exists between TL sensitivity and the amount of damage produced artificially by bombarding apatite crystals with different fluences of ∼30 MeV α-particles from a cyclotron. These results indicate that the presence of radiation damage in this mineral (viz., fluorapatite) can severely affect its TL sensitivity (i.e. TL output per unit test dose). The effect of crystal composition on the thermoluminescence and fission track annealing properties of mineral apatite is also reported. We have found that fission track annealing sensitivity and TL sensitivity are both significantly lower in samples of chlorapatite than in samples consisting predominantly of fluorapatite. (author)

Thermoluminescent response of calcium di aluminate intrinsic and doped with Cr3+

International Nuclear Information System (INIS)

Ceron R, P. V.; Vallejo H, M. A.; Sosa A, M. A.; Montes R, E.; Diaz G, J. A. I.; Diaz T, L. A.

2017-10-01

In numerous studies the thermoluminescent response (Tl) of aluminum oxide has been presented in which various dopants have been incorporated to increase the number of defects and thus modify their dosimetric properties. In related materials such as aluminates have been doped with trivalent ions and their optical characteristics have been determined. Due to this background, the motivation to study the aluminates as possible thermoluminescent dosimeters arises. In this work the synthesis of intrinsic calcium aluminate powders and doped with Cr 3+ is presented by the combustion method, to elaborate pellets and evaluate their Tl response with different radiation sources. The material obtained was characterized by XRD, X-ray fluorescence and UV-Vis; it was found to belong to the monoclinic phase of calcium di aluminate (CaAl 4 O 7 ) with a crystal size of 55 nm, the presence of Cr 3+ in the crystal lattice was also observed. The samples showed a good response Tl for UV radiation, X-rays from a 70 kV source and for Co-60 gammas. The results found show that CaAl 4 O 7 is a good candidate to study its dosimetric properties. (Author)

Crystal scintillators for use in check-light source for thermoluminescent systems

Energy Technology Data Exchange (ETDEWEB)

Nagpal, J.S.; Sabharwal, S.C.; Chougaonkar, M.P.; Godbole, S.V

1999-08-11

Beta ({sup 63}Ni, E{sub max} 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi{sub 4}Ge{sub 3}O{sub 12} and CdWO{sub 4} has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported. (author)

Infrared luminescence and thermoluminescence of lithium borate glasses doped with Sm3+ ions

Directory of Open Access Journals (Sweden)

Anjaiah J.

2015-03-01

Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with Sm3+ ions Li2O-MO-B2O3 (where MO=ZnO, CaO, CdO glasses have been studied in the temperature range of 303 to 573 K. All the pure glasses exhibited single TL peaks at 382 K, 424 K and 466 K. When these glasses were doped with Sm3+ ions no additional peaks have been observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve was found to be maximum for Sm3+ doped glasses mixed with cadmium oxide as a modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen’s formulae. The possible use of these glasses in radiation dosimetry has been described. The results clearly showed that samarium doped cadmium borate glass has a potential to be considered as a thermoluminescence dosimeter.

Analysis of the thermoluminescent signal in the hydroxyapatite synthesized by the sol-gel method; Analisis de la senal termoluminiscente en la hidroxiapatita sintetizada por el metodo sol gel

Energy Technology Data Exchange (ETDEWEB)

Mendoza A, D.; Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Lobato, M.; Rubio, E.; Rodriguez L, V. [Fac. de Ingenieria Quimica, BUAP, Av. San Claudio y 18 Sur, Col. San Manuel, 72570 Puebla (Mexico); Custodio, E. [Universidad Juarez Autonoma de Tabasco, DACB, Carr. Cunduacan-Jalpa Km. 1.5, 86680 Tabasco (Mexico)

2004-07-01

The physical properties of the ceramics are related with the chemical bonds and the crystalline structure, because the elements that constitute it can be united by ionic bonds or partially ionic giving a covalent character, this last causes that the outer layer is full of electrons. This property makes that the ceramic ones become interesting materials for thermoluminescent applications, as it demonstrates through the recent works presented on the hydroxyapatite that is a ceramic biomaterials that has shown an interesting thermoluminescent signal when being exposed to gamma radiation. In this sense, this work presents the thermoluminescent signal analysis induced by the UV and gamma radiation in a particular type of hydroxyapatite synthesized by sol gel method in which the temperature synthesis is varied. The final thermoluminescent sensitivity of materials is correlated with the crystalline degree, which is analysed through X-ray diffraction. (Author)

Método Ágil aplicado ao desenvolvimento de software confiável baseado em componentes

OpenAIRE

Alan Braz

2013-01-01

Resumo: Os Métodos Ágeis, ou Desenvolvimento Ágil de Software (DAS), tem se popularizado, na última década, por meio de métodos como Extreme Programming (XP) e Scrum e isso fez com que fossem aplicadas no desenvolvimento de sistemas computacionais de diversos tamanhos, complexidades técnica e de domínio, e de rigor quanto à confiabilidade. Esse fato evidencia a necessidade de processos de desenvolvimento de software que sejam mais rigorosos e que possuam uma quantidade adequada de modelagem e...

Fatal defect in computerized glow curve deconvolution of thermoluminescence

International Nuclear Information System (INIS)

Sakurai, T.

2001-01-01

The method of computerized glow curve deconvolution (CGCD) is a powerful tool in the study of thermoluminescence (TL). In a system where the plural trapping levels have the probability of retrapping, the electrons trapped at one level can transfer from this level to another through retrapping via the conduction band during reading TL. However, at present, the method of CGCD has no affect on the electron transition between the trapping levels; this is a fatal defect. It is shown by computer simulation that CGCD using general-order kinetics thus cannot yield the correct trap parameters. (author)

Thermoluminescence of the Z centre in Mg-doped KCl

International Nuclear Information System (INIS)

Kamavisdar, V.S.; Deshmukh, B.T.

1980-01-01

Optical absorption and thermoluminescence measurements on KCl:Mg 2+ are reported. Bleaching in F band introduces a new glow peak at 406 K in the glow curves. A similar peak is observed in microcrystalline powders. When this peak is thermally cleaned, the broadening of the absorption observed in prolonged F bleached crystals is removed. On the basis of these observations, the glow peak at 406 K is tentatively attributed to Z 1 centres. The glow peak at 394 K observed in microcrystalline powders is attributed to a combined effect of deformation and Z 1 centres. (author)

Exoemission and thermoluminescence from human enamel and shark enameloid

International Nuclear Information System (INIS)

Davies, J.E.

1983-01-01

Simultaneous measurements of exoelectron emission and thermoluminescence from powdered biological apatites, which have not been chemically or thermally pretreated, are reported. Recycling, that is, consecutive irradiation and non-isothermal scanning, is shown to change both the form of the glow curves and emissivity of samples. Two biological apatites of the hydroxyapatite type (human enamel) and fluorapatite type (shark enameloid) are compared. Although their initial glow curves are different, recycling renders the glow curves similar suggesting that the defects involved are a product of the host lattice. The relevance of exoemission as a ''fingerprinting'' technique for biologically reactive material is discussed. (author)

Detecting irradiation of strawberries by means of thermoluminescence measurement

International Nuclear Information System (INIS)

Heide, L.; Guggenberger, R.; Boegl, K.W.

1989-01-01

Investigations into the origin of the thermoluminescence (TL) have shown that this effect is due to trace amounts of mineral particulates adhering to the irradiated material. This result and own experience have led to the development of the TL-based method for post-factum detection of an irradiation of strawberries. In addition to the analysis of whole fruits, a method has been tested that proceeds via separation of adhering matter to separate TL analysis of the particulates. The results obtained so far show no difference or improvement as compared to whole-fruit TL analysis. (orig./MG) [de

Development of BaSO sub 4 :Eu thermoluminescence phosphor

CERN Document Server

Madhusoodanan, U; Lakshmanan, A R

1999-01-01

A highly sensitive thermoluminescence (TL) phosphor based on BaSO sub 4 :Eu was developed following the coprecipitation technique and firing in argon atmosphere at 1123 K. Photoluminescence studies confirm that firing in argon atmosphere instead of air increased the incorporation of Eu ions in 2+ valence state. At low gamma-ray doses, its TL sensitivity is nearly 2 to 3 times higher than that of CaSO sub 4 :Dy phosphor. The other salient features of this BaSO sub 4 :Eu TL phosphor are a constant glow curve shape and a nearly linear gamma-ray dose response.

Polynomial expressions of electron depth dose as a function of energy in various materials: application to thermoluminescence (TL) dosimetry

Energy Technology Data Exchange (ETDEWEB)

Deogracias, E.C.; Wood, J.L.; Wagner, E.C.; Kearfott, K.J

1999-02-11

The CEPXS/ONEDANT code package was used to produce a library of depth-dose profiles for monoenergetic electrons in various materials for energies ranging from 500 keV to 5 MeV in 10 keV increments. The various materials for which depth-dose functions were derived include: lithium fluoride (LiF), aluminium oxide (Al{sub 2}O{sub 3}), beryllium oxide (BeO), calcium sulfate (CaSO{sub 4}), calcium fluoride (CaF{sub 2}), lithium boron oxide (LiBO), soft tissue, lens of the eye, adiopose, muscle, skin, glass and water. All materials data sets were fit to five polynomials, each covering a different range of electron energies, using a least squares method. The resultant three dimensional, fifth-order polynomials give the dose as a function of depth and energy for the monoenergetic electrons in each material. The polynomials can be used to describe an energy spectrum by summing the doses at a given depth for each energy, weighted by the spectral intensity for that energy. An application of the polynomial is demonstrated by explaining the energy dependence of thermoluminescent detectors (TLDs) and illustrating the relationship between TLD signal and actual shallow dose due to beta particles.

O desenvolvimento do conhecimento na Pesquisa e Desenvolvimento e o registro através de patentes no Brasil – uma experiência profissional

Directory of Open Access Journals (Sweden)

Cynthia Helena Soares Bouças Teixeira

2017-11-01

Full Text Available Este trabalho tem como objetivo fornecer um detalhamento sobre o processo de busca do conhecimento, partindo de uma ferramenta básica que é a informação. No contexto que envolve Pesquisa & Desenvolvimento, o conhecimento pode ser estruturado para o desenvolvimento de novas tecnologias, produtos ou processos, em que o registro do conhecimento pode ocorrer  através das patentes. Dado que é preciso conhecer a legislação do país de depósito,trataremos mais especificamente do sistema de registro de patentes brasileiro denominado Instituto Nacional da Propriedade Intelectual – INPI. As reflexões apresentadas são provenientes de uma experiência profissional.

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.

Nutrição e desenvolvimento Nutrition and development

Directory of Open Access Journals (Sweden)

Ilma K. G. de Arruda

1994-09-01

Full Text Available As discussões sobre desenvolvimento e nutrição freqüentemente se realizam sob um duplo enfoque: aqueles que consideram o estado nutricional como reflexo do desenvolvimento, e os que admitem que a nutrição influencia fortemente no nível e ritmo desse desenvolvimento. Os autores focalizam o tema visualizando a nutrição como um fator decisivo para um bom desenvolvimento social e econômico, particularizando o fato de que as intervenções nutricionais podem contribuir para melhorias significativas nos resultados escolares, na produtividade do trabalho e na resistência às infecções. Assim, os reflexos da desnutrição na economia seriam evidentes: quer pelas limitações na expectativa de renda, quer pelo aumento dos custos dos compromissos que a população assume para proteger-se, quer pelos avultados custos ocultos de origem social - absenteísmo, acidentes do trabalho e rotatividade de pessoal. Em face dos propósitos de modernização e competitividade da economia, é inquestionável a necessidade da nutrição figurar bem alto na lista de prioridades nacionais. Com isso, promover-se-ia o desenvolvimento dos recursos humanos e a preservação desse capital, que é o ideário de uma economia socialmente responsável.Discussions on development and nutrition frequently have a double focus: one that considers nutritional status as a reflection of development, and another that admits that nutrition strongly influences the level and rhythm of development. The authors view nutrition as a decisive factor for adequate social and economic development, specifying the fact that nutritional interventions might contribute to significant improvements in individual classroom performance, productivity at the workplace, and resistance to infections. The implications of malnutrition for the economy are thus evident: either by limitations in income expectations, increased costs deriving from burdens assumed by the population to protect themselves, or

Auto-regenerative thermoluminescence dating using zircon inclusions

International Nuclear Information System (INIS)

Templer, R.H.

1993-01-01

Fired ceramics containing zircon inclusions have been dated by allowing the zircons to regenerate their own thermoluminescence (TL) signal, hence auto-regenerative TL dating. The technique is conceptually straightforward. One first measures the TL accrued since the last heating of the material. The zircon grains are then stored for six months and the TL signal regenerated through self-irradiation is measured. Since the internal dose-rate for zircon is dominated by the internal component the age of the sample is simply given by the ratio of the natural to auto-regenerated signal times the laboratory storage period. The technique, however, requires the measurement of a very small auto-regenerated signal, which introduces a number of experimental and physical complications. The methods for overcoming these problems and successfully dating zircons by auto-regeneration are described. (Author)

Desenvolvimento moral: considerações teóricas a partir de uma abordagem sociocultural construtivista

Directory of Open Access Journals (Sweden)

Martins Lincoln Coimbra

2001-01-01

Full Text Available Partindo da análise de trabalhos tradicionalmente realizados na área de desenvolvimento moral, o artigo sinaliza a necessidade de desenvolver uma abordagem teórica que trate o tema dentro de um enfoque que considere os aspectos socioculturais, cognitivos e afetivos. A questão central reside em abordar de forma sistêmica e integrada a dinâmica do desenvolvimento moral do indivíduo, resgatando a dimensão interativa e contextual envolvida na resolução dos conflitos morais e no desenvolvimento de crenças e valores. O trabalho parte dos pressupostos da perspectiva histórica socio-cultural construtivista do desenvolvimento humano, explicitando as exigências metodológicas implicadas na adoção dos conceitos e categorias utilizados no âmbito de tal perspectiva.

Desenvolvimento moral: considerações teóricas a partir de uma abordagem sociocultural construtivista

Directory of Open Access Journals (Sweden)

Lincoln Coimbra Martins

Full Text Available Partindo da análise de trabalhos tradicionalmente realizados na área de desenvolvimento moral, o artigo sinaliza a necessidade de desenvolver uma abordagem teórica que trate o tema dentro de um enfoque que considere os aspectos socioculturais, cognitivos e afetivos. A questão central reside em abordar de forma sistêmica e integrada a dinâmica do desenvolvimento moral do indivíduo, resgatando a dimensão interativa e contextual envolvida na resolução dos conflitos morais e no desenvolvimento de crenças e valores. O trabalho parte dos pressupostos da perspectiva histórica socio-cultural construtivista do desenvolvimento humano, explicitando as exigências metodológicas implicadas na adoção dos conceitos e categorias utilizados no âmbito de tal perspectiva.

Evaluation of fading factor and self-dose for glass dosimeter and thermoluminescence dosimeter

International Nuclear Information System (INIS)

Yamasaki, T.; Yamanishi, H.; Miyake, H.; Komura, K.

2000-01-01

The glass dosimeter (GD) and thermoluminescence dosimeter (TLD) are both passive radiation detectors. They are often used for measuring environmental radiation. In order to measure low dose rate preciously, it is important to evaluate decreased dose due to fading and self-dose during the exposure period. We evaluate the fading factor and self-dose of thee passive detectors, GD and TLD. We select Ogoya tunnel for the experiment. The tunnel is suitable field for measuring faded dose and self-dose because it is low cosmic radiation. At the center of the tunnel, the intensity of cosmic ray is reduced to about 1/177 than the outside of the funnel. We prepared two sets of dosimeters. One set consists of five GDs, five TLDs and some pre-irradiated GDs and TLDs that are exposed to standard radiation of 4 mGy by Cs-137. These dosimeters are put in the 10 cm thick lead box in order to shield the terrestrial gamma ray. One set is located at the center of the tunnel and the other is the outside of the funnel. The dosimeters were exposed for ten months, from May 1998 to March 1999. After the exposure, the readers of dosimeters are carried into the funnel to read out the signals promptly as soon as taking out the dosimeters. As a result of the measurement, four kinds of data are taken for GD and TLD respectively. Assumed that the self-dose and cosmic ray are constant during exposure, the four independent unknown quantities, a self-dose a dose due to cosmic ray and a fading coefficient at the center of the tunnel and at the outside, are considered. Therefore four simultaneous equations should be obtained. From these examinations, the faded dose of GD is less than 1%, but that of TLD is about 16% during ten months. The coefficient for compensation of fading of GD and TLD is given as the half of the each value. At the outside of the tunnel, the measured dose rate of cosmic ray that can pass through the 10 cm lead is evaluated to be about 16 nGy/h by both detectors. The self

Effect of thermal decomposition of hydroxyapatite on the thermoluminescent response

Energy Technology Data Exchange (ETDEWEB)

Sandoval C, K. J.; Zarate M, J.; Lemus R, J. [Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Investigaciones Metalurgicas, Ciudad Universitaria, Edificio U, 58060 Morelia, Michoacan (Mexico); Rivera M, T., E-mail: karlasandovalc@gmail.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico)

2014-08-15

In this work, a study on the thermoluminescence (Tl) induced by gamma radiation in synthetic hydroxyapatite (Hap) annealed at different temperatures obtained by the precipitation method is presented. Synthesis of hydroxyapatite Hap was carried out starting from inorganic precursors [Ca(NO{sub 3}){sub 2}·4H{sub 2}O and (NH{sub 4}){sub 2}HPO{sub 4}]. The precipitate was filtered, washed, dried and then the powder was calcined at different temperatures until the Hap decomposition. The structural and morphological characterization was carried out using both X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques. Thermoluminescent (Tl) properties of Hap powders were irradiated at different gamma radiation doses. According to X ray diffraction patterns, the tricalcium diphosphate phase (Tcp) appear when the Hap was calcined at 900 grades C. Tl glow curve showed two peaks located at around 200 and 300 grades C, respectively. Tl response as a function of gamma radiation dose was in a wide range from 25 to 100 Gy. The fading of the Tl response at 134 days after irradiation was measured. Experimental results showed that the synthetic hydroxyapatite obtained by precipitation technique may have dosimetric applications when is annealed at temperature of 900 grades C, where the Tcp phase appears and contributes to Tl response, which opens the possibility of using this biomaterials in the area of dosimetry, as they are generally used for biomedical implants. (author)

Proton induced target fragmentation studies on solid state nuclear track detectors using Carbon radiators

Science.gov (United States)

Szabó, J.; Pálfalvi, J. K.; Strádi, A.; Bilski, P.; Swakoń, J.; Stolarczyk, L.

2018-04-01

One of the limiting factors of an astronaut's career is the dose received from space radiation. High energy protons, being the main components of the complex radiation field present on a spacecraft, give a significant contribution to the dose. To investigate the behavior of solid state nuclear track detectors (SSNTDs) if they are irradiated by such particles, SSNTD stacks containing carbon blocks were exposed to high energy proton beams (70, 100, 150 and 230 MeV) at the Proteus cyclotron, IFJ PAN -Krakow. The incident protons cannot be detected directly; however, tracks of secondary particles, recoils and fragments of the constituent atoms of the detector material and of the carbon radiator are formed. It was found that as the proton energy increases, the number of tracks induced in the PADC material by secondary particles decreases. From the measured geometrical parameters of the tracks the linear energy transfer (LET) spectrum and the dosimetric quantities were determined, applying appropriate calibration. In the LET spectra the LET range of the most important secondary particles could be identified and their abundance showed differences in the spectra if the detectors were short or long etched. The LET spectra obtained on the SSNTDs irradiated by protons were compared to LET spectra of detectors flown on the International Space Station (ISS): they were quite similar, resulting in a quality factor difference of only 5%. Thermoluminescent detectors (TLDs) were applied in each case to measure the dose from primary protons and other lower LET particles present in space. Comparing and analyzing the results of the TLD and SSNTD measurements, it was obtained that proton induced target fragments contributed to the total absorbed dose in 3.2% and to the dose equivalent in 14.2% in this particular space experiment.

Comparing of the yield curve of the pediatric X-ray equipment using thermoluminescent dosimeters and cylindrical ionization chamber; Comparacao da curva de rendimento de um aparelho de raios X pediatrico utilizando dosimetros termoluminescentes e camara de ionizacao cilindrica

Energy Technology Data Exchange (ETDEWEB)

Filipov, Danielle, E-mail: dfilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Schelin, Hugo R., E-mail: ledesmaiorgealberto@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil); Tilly Junior, Joao G., E-mail: joao.tilly@derax.com.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Hospital de Clinicas

2014-07-01

The determination of the yield curve of a radiographic equipment should be realized once a year, or when the unit be serviced. Besides being a requirement of ANVISA, through this test is possible to determine the incident air kerma (at a given point in the center of the beam) - INAK. Based on these concepts, the main objective of this work is the comparison of yield curves of the pediatric X-ray apparatus using two different detectors: one cylindrical ionization chamber and thermoluminescent dosimeters type LiF: Mg, Cu, P, as per protocol RLA / 9/057 IAEA. Then the equation of the yield curve (generated by each detector) was used to determine the INAK of 10 pediatric examinations, performed on this equipment. After the process of calibration of both detectors, they were placed side by side at a focus of the tube equipment for determining the performance of the same curve. Finally, using the curves generated by two detectors, INAK values of the 10 tests were calculated (from the kVp values, and mAs focus-patient of each exams), generating difference values at most 5%. As a conclusion, it can be said that the TLD lithium fluoride doped with Mg, Cu and P and the cylindrical ionization chambers may be used satisfactorily to determine the yield curve, whether as quality control or dosimetry.

Determination of the dose index in computerized tomography using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Azorin, J.C.; Calderon, A.; Azorin, J.

2004-01-01

In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with {sup 60}Co; Deteccion y termoluminiscencia del cilantro (Coriandrum sativum L.) irradiado con {sup 60}Co

Energy Technology Data Exchange (ETDEWEB)

Ruiz G, B. [Departamento de Agricultura y Ganaderia, Universidad de Sonora, 083190 Hermosillo, Sonora (Mexico); Cruz Z, E. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, UNAM, A. P. 70-543, 04510 Mexico D. F. (Mexico); Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, 083190 Hermosillo, Sonora (Mexico)

2009-10-15

The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 {mu}m by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with {sup 60}Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

The influence of thyroid geometry on the response of LiF and CaSO4 thermoluminescent discs to 131I and 125I irradiation

International Nuclear Information System (INIS)

O'Connor, M.K.; Malone, J.F.; Cullen, M.J.

1978-01-01

Recent work has demonstrated that LiF and CaSO 4 thermoluminescent discs may be used to monitor the effective half-life of radioiodine in the thyroid in man. To provide a firm basis for the work, the radiation field presented by model thyroids to thermoluminescent discs on the surface of a neck phantom has been examined in detail. The influence of thyroid mass, depth and lobe separation, factors which in practice are highly variable, has also been determined. The results demonstrate that the method is sufficiently sensitive to measure less than 0.5 μCi of 131 I or 125 I in the human thyroid, and that effective half-life determinations should not be influenced by minor positioning errors which may be encountered when placing thermoluminescent discs on the neck surface. (author)

Thermoluminescence analysis of irradiated oyster shells

International Nuclear Information System (INIS)

Cruz-Zaragoza, E.; Marcazzó, J.; Della Monaca, S.; Boniglia, C.; Gargiulo, R.; Bortolin, E.

2012-01-01

This paper reports the thermoluminescence (TL) analysis performed on the oyster shells powder. TL response of 60 Co gamma-rays irradiated samples were studied in the range from 80 Gy to 8 kGy doses. TL signal of irradiated shell powder was higher as compared to the unirradiated control samples, which allowed to identify the irradiated oysters. Results show that the oyster shells have good TL properties and can be useful for the identification of irradiated seafood as well as for the evaluation of the treatment dose. - Highlights: ► TL properties of irradiated oyster shell powder were studied. ► The SEM analysis shows that several elements are present in oyster shell powder. ► Calcite is the main component in the samples and β-calcite is also present. ► Following the European Standard EN 1788, the irradiated oyster can be identified. ► Determination of absorbed dose is possible by performing a preheat treatment.

Thermoluminescence of zircon: a kinetic model

CERN Document Server

Turkin, A A; Vainshtein, D I; Hartog, H W D

2003-01-01

The mineral zircon, ZrSiO sub 4 , belongs to a class of promising materials for geochronometry by means of thermoluminescence (TL) dating. The development of a reliable and reproducible method for TL dating with zircon requires detailed knowledge of the processes taking place during exposure to ionizing radiation, long-term storage, annealing at moderate temperatures and heating at a constant rate (TL measurements). To understand these processes one needs a kinetic model of TL. This paper is devoted to the construction of such a model. The goal is to study the qualitative behaviour of the system and to determine the parameters and processes controlling TL phenomena of zircon. The model considers the following processes: (i) Filling of electron and hole traps at the excitation stage as a function of the dose rate and the dose for both (low dose rate) natural and (high dose rate) laboratory irradiation. (ii) Time dependence of TL fading in samples irradiated under laboratory conditions. (iii) Short time anneali...

Thermoluminescence dating of Brazilian indigenous ceramics

International Nuclear Information System (INIS)

Farias, T. M. B.; Gennari, R. F.; Etchevarne, C.; Watanabe, S.

2009-01-01

Two indigenous ceramics fragments, one from Lagoa Queimada (LQ) and another from Barra dos Negros (BN), both sites located on Bahia state (Brazil), were dated by thermoluminescence (TL) method. Each fragment was physically prepared and divided into two fractions, one was used for TL measurement and the other for annual dose determination. The TL fraction was chemically treated, divided in sub samples and irradiated with several doses. The plot extrapolation from TL intensities as function of radiation dose enabled the determination of the accumulated dose (D ac ), 3.99 Gy and 1.88 Gy for LQ and BN, respectively. The annual dose was obtained through the uranium, thorium and potassium determination by ICP-MS. The annual doses (D an) obtained were 2.86 and 2.26 mGy/year. The estimated ages were ∼1375 and 709 y for BN and LQ ceramics, respectively. The ages agreed with the archaeologists' estimation for the Aratu and Tupi tradition periods, respectively. (authors)

Avaliação do crescimento e desenvolvimento de crianças institucionalizadas

Directory of Open Access Journals (Sweden)

Caroline Magna Pessoa Chaves

2013-10-01

Full Text Available O estudo objetivou avaliar o crescimento e desenvolvimento de crianças de 0 a 6 anos institucionalizadas. Abordagem descritiva, transversal e de natureza quantitativa. Foi realizado em um abrigo da Secretaria do Trabalho e Desenvolvimento Social do Governo do Estado do Ceará, nos meses de março e abril de 2011. A amostra foi composta por 44 crianças. Prevaleceram crianças de sexo masculino (59,1%; faixa etária entre 24 a 72 meses (56,8%, e tempo de abrigamento superior a um ano (72,7%. Verificou-se que as crianças estavam na faixa de normalidade nutricional. Porém, 65,9% das crianças não alcançaram pelo menos um dos marcos do desenvolvimento propostos pelo Ministério da Saúde. O estudo possibilitou uma reflexão sobre como as crianças residentes em abrigos estão sendo assistidas pela equipe de saúde, tornando-se necessário realizar o acompanhamento de seu crescimento e desenvolvimento, a fim de intervir sobre as alterações encontradas.

Photoluminescence and thermoluminescence characterization of Eu3+- and Dy3+ -activated Ca3(PO4)2 phosphor

International Nuclear Information System (INIS)

Nagpure, I.M.; Saha, Subhajit; Dhoble, S.J.

2009-01-01

Rare-earth-doped polycrystalline Ca 3 (PO 4 ) 2 :Eu, Ca 3 (PO 4 ) 2 :Dy and Ca 3 (PO 4 ) 2 :Eu,Dy phosphors prepared by a modified solid-state synthesis has been studied for its X-ray diffraction, thermoluminescence (TL) and photoluminescence (PL) characteristics. The PL emission spectra of the phosphor suggest the presence of Eu 3+ ion in Ca 3 (PO 4 ) 2 :Eu and Dy 3+ ion in Ca 3 (PO 4 ) 2 :Dy lattice sites. The TL glow curve of the Ca 3 (PO 4 ) 2 :Eu compounds has a simple structure with a prominent peak at 228 deg. C, while Ca 3 (PO 4 ) 2 :Dy peaking at 146 and 230 deg. C. TL sensitivity of phosphors are compared with CaSO 4 : Dy and found 1.52 and 1.20 times less in Ca 3 (PO 4 ) 2 :Eu and Ca 3 (PO 4 ) 2 :Dy phosphors, respectively. The Ca 3 (PO 4 ) 2 :Eu,Dy phosphors shows switching behavior under two different excitation wavelengths and enhancement in PL intensity of Dy 3+ ions were reported. The paper discusses the photoluminescence and thermoluminescence behavior of Eu 3+ and Dy 3+ ion in Ca 3 (PO 4 ) 2 hosts, it may be applicable to solid-state lighting as well as thermoluminescence dosimetry applications.

Crystal growth and thermoluminescence response of NaZr2(PO4)3 at high gamma radiation doses

International Nuclear Information System (INIS)

Ordóñez-Regil, E.; Contreras-Ramírez, A.; Fernández-Valverde, S.M.; González-Martínez, P.R.; Carrasco-Ábrego, H.

2013-01-01

Graphical abstract: -- Highlights: •NaZr 2 (PO 4 ) 3 exposed to gamma doses of 10, 30 and 50 MGy. •Gamma radiation produced growth of the crystal size of the NZP. •Morphology changes were reversible by heating. •Linear relationship between the thermoluminescence and the applied gamma dose. •This property could be useful for high-level gamma dosimetry. -- Abstract: This work describes the synthesis and characterization of NaZr 2 (PO 4 ) 3 . The stability of this material under high doses of gamma radiation was investigated in the range of 10–50 MGy. Samples of unaltered and gamma irradiated NaZr 2 (PO 4 ) 3 were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and thermoluminescence. The results showed that while functional groups were not affected by the gamma irradiation, morphology changes were observed with increasing doses of gamma irradiation. The morphology of the non-irradiated compound is agglomerated flakes; however, irradiation at 10 MGy splits the flakes inducing the formation of well-defined cubes. Gamma irradiation induced the crystal size of the NaZr 2 (PO 4 ) 3 to grow. The heat treatment (973 K) of samples irradiated at 50 MGy resulted in the recovery of the original morphology. Furthermore, the thermoluminescence analysis of the irradiated compound is reported

Dating the Morasko meteorite fall by natural thermoluminescence of the fusion crust

Directory of Open Access Journals (Sweden)

Fedorowicz Stanisław

2016-09-01

Full Text Available The date of fall of the Morasko iron meteorite was determined by means of thermoluminescence measurements of the fusion crust and related local materials. Three small pieces, commonly referred to as ‘shrapnel’, were used. The results obtained are 4.5-5.0 ka, which is in good agreement with previous estimates of 4-6 ka on the basis of radiometric, do-simetric and palynological methods.

Interpretation of the thermoluminescent curve by means of a Fermi-Dirac distribution

International Nuclear Information System (INIS)

Nieto H, B.; Azorin N, J.; Vazquez C, G.A.

2002-01-01

This work has the purpose to present in a preliminary form an alternative of the theoretical study of the thermoluminescence phenomena as a first approach to the quantum aspect on the behavior of the systems formed by fermions which take part in the said phenomena. In that way, an analogous expression to the Randall-Wilkins more general is obtained, for kinetics of first order, taking a Fermi-Dirac distribution. (Author)

Study of a new glass matrix by the thermoluminescence technique; Estudo de uma nova matriz vitrea pela tecnica de termoluminescencia

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Pamela Z.; Vedovato, Uly P.; Cunha, Diego M. da; Dantas, Noelio O.; Silva, Anielle C.A.; Neves, Lucio P.; Perini, Ana P., E-mail: anapaula.perini@ufu.br [Universidade Federal de Uberlandia (INFIS/UFU), MG (Brazil). Instituto de Fisica; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carrera, Betzabel N.S.; Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica

2015-07-01

The thermoluminescence technique is widely used for both personal and for high-dose dosimetry. In this work, the thermoluminescence technique was utilized to study a new glass matrix, with nominal composition of 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.20BaO.50B{sub 2}O{sub 3} (mol%), irradiated with different doses in a {sup 60}Co source. The glow curves and the dose-response curve were obtained for radiation doses between 50 Gy and 900 Gy. The results showed that this new glass matrix presents potential use in high-dose dosimetry. (author)

Abordagem grassroots e resistência: atualizando a concepção de desenvolvimento sustentável

Directory of Open Access Journals (Sweden)

Augusto Marcos Carvalho de Sena

Full Text Available Resumo Em contrapartida às especificidades impositivas do modelo de produção capitalista - incluindo-se nesse modelo os meandros de arranjos produtivos que inserem o meio ambiente enquanto alinhado à versão tríplice da concepção tradicional de desenvolvimento sustentável -, tem surgido uma massa crítica de literatura focada na resistência ao modo de funcionamento do capitalismo ocidental. Em relação à teoria, economia solidária (pilar econômico, movimentos sociais (pilar social, ecologia política (pilar ambiental e raízes culturais (pilar cultural são aparatos importantes que não devem ficar à margem na estruturação de uma concepção alternativa do desenvolvimento sustentável. Tais aparatos são considerados elementos de resistência, visto terem fatores diferenciados quando comparados com as características tradicionais dos pilares da criticada concepção de desenvolvimento sustentável. Assim, o objetivo do presente ensaio teórico é conceber alternativas à concepção padrão do desenvolvimento sustentável, considerando aspectos da abordagem grassroots importantes para esse propósito. A contribuição é relevante tendo em vista a consideração de aspectos alternativos e complementares envolvidos na leitura da atualização conjecturada. Os prospectos do desenvolvimento grassroots têm sido usados como guia prático em ações de desenvolvimento local envolvendo comunidades menos desenvolvidas em várias partes do mundo, sem a conjectura que sinaliza para elementos conceituais que podem oferecer uma conformação alternativa à concepção do desenvolvimento sustentável. Conclui-se que a versão tradicional do desenvolvimento sustentável pode ser atualizada com elementos alternativos advindos da abordagem grassroots.

Desenvolvimento de um detector piezelétrico para cromatógrafo a gás interfaceado a microcomputador

Directory of Open Access Journals (Sweden)

Jesus Dosil P. de

1999-01-01

Full Text Available A piezoelectric detector based on a commercial quartz crystal of 3.57MHz is shown. A PTFE cell attached to the GC-column outlet holds the polymer-coated crystal, whose terminals were removed. Two TTL oscillators (reference and sensor are used and the beating of their frequencies is monitored through a home-made counter card inserted in a microcomputer. The original thermal conductivity detector was also interfaced, but through a 12-bit analog-to-digital converter. In spite of the well-known fact that QCM has low sensitivity at high temperatures, results show significant peak deformation for low temperatures. In addition, the phenomenon is also dependent on the chemical composition of the absorbent film besides instantaneous partial pressure and chemical composition of the analyte.