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Sample records for lif tld-100 irradiated

  1. Thermoluminescence of pure LiF and Lif (TLD-100) irradiated at room temperature; Termoluminiscencia en LiF puro y LiF dosimetrico (TLD-100), irradiados a temperatura ambiente

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    Sagastibelza Chivite, F.

    1980-07-01

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

  2. Comparative study of thermoluminescent properties of LiF: Mg, Cu, P, LiF: Mg, Ti and TLD-100 irradiated with X-rays; Estudio comparativo de las propiedades termoluminiscentes de LiF: Mg, Cu, P, LiF: Mg, Ti y TLD-100 irradiados con rayos X

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    Azorin, J.; Rivera, T.; Gonzalez, P.; Ortega, X.; Ginjaume, M. [Universidad Autonoma Metropolitana-Iztapalapa, 09000 Mexico D.F. (Mexico)

    2000-07-01

    The thermoluminescent properties (Tl) of LiF: Mg, Cu, P, and LiF: Mg, Ti, were investigated both developed in Mexico and comparing them with the properties of TLD-100 when they are exposure to X-rays. The Tl curve of LiF: Mg, Cu, P exhibited two peaks at 200 and 300 Centigrade. Its response Tl in function of dose resulted linear in the interval of 0.5 Gy until 5 Gy and its sensitivity to X-ray was around 25 times greater that of the TLD-100. Also it was measured the Tl response of the three materials in function of photon energy. The results showed that LiF: Mg, Cu, P has potential to be used as X-ray dosemeter. (Author)

  3. Comments on ``large enhancement of TLD-100 sensitivity by irradiation in a reactor core''

    Science.gov (United States)

    Lakshmanan, A. R.; Chandra, Bhuwan; Bhatt, R. C.

    1987-06-01

    The large enhancement of TLD-100 sensitivity on irradiation in a reactor core reported by Lau et al. [Nucl. Instr. and Meth. B17 (1986) 170] is false and is in complete contradiction with the results reported earlier in the literature and with our recent findings. Lau et al. have misinterpreted the TL signal from thermal neutron induced 3H betas in LiF as due to enhanced TL sensitivity because of neutron induced traps/luminescent centres.

  4. A new interpretation of the thermoluminescence and isothermal decay of LiF TLD-100

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    Dorendrajit Singh, S.; Gartia, R.K. (Manipur Univ. (India). Dept. of Physics)

    1993-01-14

    Some of the published experimental results on the thermoluminescence and isothermal decay of LiF TLD-100 have been explained on the basis of a continuous uniform trap distribution within a finite range ([Delta]E) assuming first-order kinetics. This provides credibility to the results of two rival groups of workers who, in the recent past, have severely criticized the conclusions of each other in a number of publications. (Author).

  5. Computerized glow curve deconvolution: the case of LiF TLD-100

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    Gartia, R.K.; Dorendrajit Singh, S.; Mazumdar, P.S. (Manipur Univ. (India). Dept. of Physics)

    1993-05-14

    It has been accepted by a large number of workers that the glow curve of LiF TLD (Thermoluminescent dosimetry)-100 can be described by thermoluminescence (TL) peaks following the Randall-Wilkins (RW) equation, even though the model fails to explain a number of experimental facts. A further simplification of the model is the Podgorsak-Moran-Cameron (PMC) approximation which is also in use. This paper points out the limitation of the PMC approximation in deconvoluting glow curves of LiF TLD-100. (author).

  6. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon; Obtencion de eficiencias termoluminiscentes mediante irradiacion de dosimetros TLD-100 con haces de protones, helios y carbon

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    Avila, O.; Rodriguez V, M.; Aviles, P.; Gamboa de Buen, I.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

  7. Response of TLD-100 LiF dosimeters for X-rays of low energies; Respuesta de dosimetros de TLD-100 de LiF para rayos X de bajas energias

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    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, X5016LEA Cordoba (Argentina)

    2011-10-15

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

  8. Measure of the attenuation curve of a beam of X-rays with TLD-100 dosimeters of LiF; Medicion de la curva de atenuacion de un haz de rayos X con dosimetros TLD-100 de LiF

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    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, Cordoba (Argentina); Germanier, A. [Ministerio de Ciencia y Tecnologia, Ceprocor, Unidad de Estudios Fisicos, Alvarez de Arenas 230, X5004AAP Barrio Juniors, Cordoba (Argentina); Delgado, V. [Universidad Complutense de Madrid, Departamento de Fisica Medica, Ciudad Universitaria, 28040 Madrid (Spain)

    2011-10-15

    The attenuation curve of a beam of X-rays represents the beam intensity in function of the attenuator thickness interposed between the source and the detector. To know with the major possible precision the attenuation curve is indispensable in procedures of spectral reconstruction. Their periodic measuring also offers valuable information on the correct operation of a tube of X-rays, diagnostic or therapy, when not have a specific detector for that activity. In this work was measured the attenuation curve of a tube of X-rays operated to 50 kV and 0.5 ma, using existent elements in any diagnostic or therapy laboratory with radiations. In the measures commercial aluminum foil was used, bent until 24 times and thermoluminescent dosimeters TLD 100 - LiF. Also, for comparison, was measured this attenuation curve with an ionization chamber brand Capintec model 192. Was determined by X-rays fluorescence the composition of the aluminium foil, since the present elements in the alloy can to affect the form of the attenuation curve. It is interesting to observe that these elements are in very low proportion (ppm) that they do not alter the attenuation capacity of the pure aluminium. Finally in a precision balance we weigh a big piece (30 cm x 100 cm) of aluminium foil and we obtained the thickness in g/c m2. It is possible to obtain attenuation curves of a beam of X-rays, with a high precision procedure and reproducibility. The use of TLD-100 dosimeters of LiF or similar makes that this activity was also quick and simple. (Author)

  9. Use of TLD-100 to verify a dosimetric method for total electron skin irradiation

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    Mesa, F.; Sosa, M. [Physics Institute, University of Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2007-07-01

    Full text: A clinical dosimetric method for generating a homogeneous field of radiation around of patients under treatment of total skin electron irradiation and its verification using thermoluminescent dosimetry is presented. The irradiations were performed utilizing a 6 MeV electron beam generated by a Varian Clinac 21EX linear accelerator installed in the oncology unit of the IMSS-Tl hospital in Leon. Levels of radiation for diverse adjustment performed in the treatment planning system of the lineal accelerator and registered to different treatment distances using a computerized water phantom system were studied. A large batch of TLD-100 chips calibrated in terms of air-kerma rate to the standard treatment distance and positioned in an anthropomorphic Alderson Random Phantom was used. Dose verification and comparison with the measurements made with the computerized system were analyzed. A single field electron beam for treatment of total skin irradiation was implemented. Preliminary results indicate that the levels of dose homogeneities were larger than 90% for distances up to 3.0 m. The results suggest that the method developed is a reliable for delivering an electron beam with significantly homogeneity for these treatments. Analyses and results of both thermoluminescent and computerized dosimetric system calibrations are also presented. (Author)

  10. Production dosimeter LiF: Mg, Ti and comparison its responses with dosimeter LiF: Mg, Ti (TLD-100 in Harshaw company against of gamma rays

    Directory of Open Access Journals (Sweden)

    KH Mohammadi

    2010-03-01

    Full Text Available Thermoluminescence dosimeters are small tablets used with 3. 2*3. 2*0. 9mm^3 for measurement of received dose from radioactive various beams. The most common dosimeter is TLD-100 which is lithium-fluoride family and this dosimeter contain magnesium impurities. In this study, first lithium-flouride powder was mixed with titanium and controlled atmosphere samples were heated. After measuring of samples density and hardness, their glow curves were drawn and microscopic pictures of producted samples were provided. Of course, the reader should know that the best press pressure, the best range of temperature heating and the best range of samples heating were determined in 6-8 (ton/cm2, 775-800 ° C and 15-20 h, respectively [1]. Then, the response of producted TLD-100 under radiation of gamma sources, 60Co, was measured in 500 mSv rate and obtained values were compared with obtained values by Harshaw producted samples. Dosimetry characteristics of producted samples was evaluated according to ASTM E 668-00, IEC-ISO 1066 standards. The results of comparisions indicate good agreements between producted sample and Harshaw sample.

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

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    Estrada E, D

    2002-07-01

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

  12. Evaluation of the Entrance Skin Dose in Animals Undergoing Diagnostic Radiology Using LiF, Mg, Ti Thermoluminescence Dosimetry (TLD-100

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    Sedigheh Sina

    2016-06-01

    Full Text Available Introduction According to the International Commission on Radiological Protection publication numbers 60 and 21, the environmental control standards should ensure human and other species protection to a desirable degree. Since application of radiographic procedures in Veterinary Medicine has increased significantly, in this study, we aimed to evaluate the entrance skin dose to the animals (e.g., dogs, cats, horses, and birds undergoing diagnostic radiology. Materials and Methods The entrance skin dose to the animals in different radiology procedures were estimated through a indirect estimation using the output of X-ray tubes and b direct measurement using LiF:Mg, Ti  (TLD-100  thermoluminescence dosimeter. Regression analysis was performed for comparison of the two methods. The animals included in this study were cats, dogs, small birds, horses, parrots, and chough. Results The dose received by the animals varied from 20 mGy to 1189.2 mGy, depending on the animal thickness, focal spot to surface distance, imaging technique, and animal type. Conclusion Optimized procedures are suggested for obtaining high-quality images, with a reasonably low dose imposed to the animals.

  13. Reproducibility study of TLD-100 dosimeters for {sup 122}I seeds used in brachytherapy

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    Zeituni, Carlos A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil); E-mail: czeituni@ipen.br; Moura, Eduardo S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faculdade Oswaldo Cruz, Sao Paulo, SP (Brazil); Manzoli, Jose E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade Sao Judas Tadeu, Sao Paulo, SP (Brazil); Terremoto, Luis A.A.; Rostelato, Maria Elisa C.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2007-07-01

    In order to provide the dosimetry for {sup 125}I seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the precision of the response will not be the same. As a consequence, they must be measured one by one. This paper presents the calculation methodology for selection procedure to TLD-100 dosimeter used, embracing 143 TLD-100 dosimeters prepared by Harshaw Company on December 19th, 2005. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. The annealing procedure used for these dosimeters consists of annealing the TLD dosimeters at 400 deg C for 65 minutes using a PC controlled annealing oven. This procedure is followed by an oven-typical cooling down profile to about 100 deg C for 127 minutes. The pre-readout thermal stabilization was used and it consists of an annealing at 100 deg C for 15 minutes. Irradiations were performed using 36 {sup 125}I seeds with activity of 0,623 mCi (23,05 MBq) on October 20th, 2006 for approximately 150 minutes, to guarantee a minimum of 5 Gy absorbed dose in each dosimeter. Different evanescence times have been used. These complete procedures were carried out four times in order to compare the data and minimize the systematic error. (author)

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

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

    1998-12-31

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

  15. An ultra-high dose of electron radiation response of Germanium Flat Fiber and TLD-100

    Science.gov (United States)

    Alawiah, A.; Amin, Y. M.; Abdul-Rashid, H. A.; Abdullah, W. S. Wan; Maah, M. J.; Bradley, D. A.

    2017-01-01

    The thermoluminescence (TL) response of Germanium Flat Fiber (GFF) and TLD-100 irradiated with 2.5 MeV electrons for the doses up to 1 MGy were studied and compared. The aim was to evaluate the TL supralinearity response at an ultra-high dose (UHD) range and to investigate the change in kinetic parameters of the glow peaks, as the doses increases up to 1 MGy. It is found that the critical dose limit (CDL) of GFF is 5 times higher as compared to TLD-100. CDL is determined by the dose at the maximum supralinearity, f(D)max. It is also found that annealing the TLD-100 and GFF with temperature more than 400 °C is required to reset it back to its original condition, following radiation doses up to 1 MGy. It is also noticed the strange behavior of Peak 4 (TLD-100), which tends to be invisible at the lower dose (<10 kGy) and starts to be appeared at the critical dose limit of 10 kGy. This result might be an important clue to understand the behavior of TLD-100 at extremely high dose range. For both samples, it is observed that the TL intensity is not saturated within the UHD range studied.

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

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

    2004-07-01

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

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

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

    2014-07-01

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

  18. TL response of LiF: Mg, Cu, P dosemeters in function of the photon energy; Respuesta TL de dosimetros de LiF: Mg, Cu, P en funcion de la energia del foton

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    Gonzalez, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2005-07-01

    In this work the obtained results of studying the response of dosemeters of LiF: Mg, Cu, P + Ptfe, developed in the ININ, commercial dosemeters GR200A (LiF: Mg, Cu, P) of chinese manufacture and TLD-100 (LiF: Mg, Ti) US are presented, when irradiating them with X rays 16, 24, 34.5, 42, 100 and 145 keV of effective energy, with gamma rays of 662 keV ({sup 137} Cs) and 1252 keV ({sup 60} Co). The results are presented in function of the sensitivity that the dosemeters showed normalized to gamma radiation of {sup 60} Co. It was appreciated that the dosemeters more equivalent to the tissue, they were those of LiF: Mg, Cu, P + Ptfe, while the less equivalent ones were the TLD-100. (Author)

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

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    Raffaele Liuzzi

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

  20. Quality control for thermoluminescent dosemeters TLD-100 de Li F: Mg, Ti for high dose rate treatments using Ir-192 sources in breast, esophagus and bronchus; Control de calidad con dosimetros thermoluminiscentes TLD-100 de Li F: Mg, Ti para tratamientos de alta tasa de dosis com fuentes de Ir-192 en canceres de seno, esofago y bronchio

    Energy Technology Data Exchange (ETDEWEB)

    Torres, F. [Universidad Nacional de Colombia, Bogota (Colombia)]. E-mail: franciscotorreshoyos@yahoo.com; Plazas, M.C. [Instituto Nacional de Cancerologia, Bogota (Colombia); Cavadia, W. [Universidad de Cordoba (Colombia)

    2004-07-01

    Rods - shaped, TLD - 100, LiF: Mg,Ti thermoluminescence dosimeters are used to check duality control during breast, esophagus and bronchus cancer treatments with high rate dose and Ir -192 source. We conclude that the specificity dose in prescription points is in agreement with parameters given in international protocols. (author)

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

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

    2014-11-07

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

  2. Comparison of the calculated absorbed dose using the Cadplan™ treatment planning software and Tld-100 measurements in an Alderson-Rando phantom for a bronchogenic treatment

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    Gutiérrez Castillo, J. G., E-mail: jggc59@hotmail.com [Departamento de Física, Hospital de Oncología, IMSS, CMN Siglo XXI, Cuauhtémoc 330 Col. Doctores (Mexico); Álvarez Romero, J. T., E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx; Calderón, A. Torres, E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx; M, V. Tovar, E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx [SSDL, Departamento de Metrología ININ, Salazar, Estado de México 15245 (Mexico)

    2014-11-07

    To verify the accuracy of the absorbed doses D calculated by a TPS Cadplan for a bronchogenic treatment (in an Alderson-Rando phantom) are chosen ten points with the following D's and localizations. Point 1, posterior position on the left edge with 136.4 Gy. Points: 2, 3 and 4 in the left lung with 104.9, 104.3 and 105.8 Gy, respectively; points 5 and 6 at the mediastinum with 192.4 and 173.5 Gy; points 7, 8 and 9 in the right lung with 105.8, 104.2 and 104.7 Gy, and 10 at posterior position on right edge with 143.7 Gy. IAEA type capsules with TLD 100 powder are placed, planned and irradiated. The evaluation of the absorbed dose is carried out a curve of calibration for the LiF response (nC) {sup vs} {sup DW}, to several cavity theories. The traceability for the DW is obtained with a secondary standard calibrated at the NRC (Canada). The dosimetric properties for the materials considered are determined from the Hounsfield numbers reported by the TPS. The stopping power ratios are calculated for nominal spectrum to 6 MV photons. The percent variations among the planned and determined D in all the cases they are < ± 3%.

  3. SU-E-T-172: Characterization of TLD-100 (LiF:Mg,Ti) Microcube Energy Response in a Cylindrical Chamber Phantom

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    Desai, V; Hammer, C; Kunugi, K; Culberson, W; DeWerd, L [University of WI-Madison/ADCL, Madison, WI (United States)

    2015-06-15

    Purpose: To characterize the energy response of TLD-100 microcubes inside a Virtual Water chamber phantom. Methods: Four TLD microcubes were placed inside a water-proof Virtual Water (VW) chamber phantom and irradiated to a known dose on a Varian linac in a 1D water tank. These chamber phantoms were then replaced by TLD-100 chips inside a separate VW paddle and irradiated to the same dose. Each energy response reading was calculated as light output per unit dose in nC/cGy and normalized to a calibration set irradiated to the same dose in 60Co. The differences in response between the TLD chips and microcubes were then analyzed. Results: Across all energies, the average microcube response was less sensitive to energy than the average chip response with both falling consistently within 2.8% of previously established values in the literature Conclusion: TLD microcubes showed a lower average sensitivity to energy than their TLD chip counterparts. The use of TLD-100 microcubes inside the chamber phantom was validated against TLD-100 chips inside of VW paddles.

  4. Tl response of LiF: Mg, Cu, P + PTFE (Mexico) and GR200A (China) dosemeters; Respuesta Tl de dosimetros de LiF: Mg, Cu, P + PTFE (Mexico) y GR200A (China)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R. [ININ, A.P. 18-1027, Mexico D.F. (Mexico); Azorin N, J.; Furetta, C. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    TLD-100 was the commercial dosemeter more known since some decades ago. This dosemeter was considered for many research groups as the reference material for developing new Tl materials for ionizing radiation dosimetry. Actually it seems that TLD-100 is going to be replaced by the Chinese material GR200A, as reference material due that this material in addition to be considered as a tissue equivalent material, is 30 to 35 times more sensitive that TLD- 100. Results of the study of the Tl response of LiF: Mg, Cu, P + Ptfe developed at ININ-Mexico, comparing them with those of GR200A are presented. These results showed that the sensitivity (s = Tl intensity/weight x dose) to gamma radiation of the LiF: Mg, Cu, P + Ptfe dosimeters was 4.34 meanwhile that of the commercial dosemeter was 3.41. Detection threshold of the dosemeters studied was 2.22 and 0.52 {mu}Gy respectively Repeatability after 10 cycles Irradiation-reading-annealing was {+-}1.39% and {+-}1.86% respectively. Both types of dosemeters presented a linear response as a function of gamma radiation in the range from 0.02 mGy and 100 Gy. (Author)

  5. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters; Proposta de um sistema postal para a calibracao de fontes de {sup 192} Ir, utilizadas em braquiterapia de alta taxa de dose, com dosimetros termoluminescentes de LiF: Mn: Ti

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V. [Instituto de Radioprotecao e Dosimetria. CNEN Caixa Postal 37750, 22780-160, Rio de Janeiro (Brazil)

    1998-12-31

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  7. A study on the behaviour of TLD-100 glow peaks at extreme ambient temperatures in Riyadh, Saudi Arabia.

    Science.gov (United States)

    Al-Haj, Abdalla N; Lagarde, Charlie S

    2006-01-01

    In this study, the temperature-induced variations in the TLD-100 response and the modifications in its glow peaks are investigated in real environmental exposure conditions in Riyadh, Saudi Arabia, where ambient temperatures during summer reach >45 degrees C and with relative humidity of 8814 TLD cardholders were deployed as environmental dosemeters for a period of approximately 1 month for 12 consecutive months. One group was irradiated to 5 mGy 137Cs prior to deployment; another was irradiated to the same dose after deployment, while the last group was left unirradiated. Analysis of glow curves was done using commercially available glow curve deconvolution software (CGCD). Monthly variations in peak 3, 4 and 5 areas relative to the corresponding peak areas of a prompt glow curve are presented. Results of this study show good TL signal compensation between peaks 4 and 5 at all ambient temperatures encountered in this experiment, despite the observed individual variations experienced by each of these peaks. The sum of peak 4 and 5 areas is constant to within approximately 10%, for both pre- and post-irradiated dosemeters, during this 12-month cycle.

  8. Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ; Determinacion de parametros cineticos en dosimetros Tl de LiF: Mg, Cu, P + PTFE desarrollados en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Basurto G, B.S

    2002-07-01

    The objective of this work, is the one of determining the kinetic parameters of the dosemeter of LiF: Mg, Cu, P + Ptfe; starting from the curves Tl obtained at being irradiated with alpha radiation ({alpha}), beta ({beta}) and gamma ({gamma}). As like to compare its sensitivity with each radiation type, considering the sensitivity of the TLD-100 as the unit. In the Chapter 1, the fundamental structure of the matter is described, making emphasis in the different radiation types, and their interaction with this. In the Chapter 2, the units are described but used in the dosimetry of the radiation. In the Chapter 3, the basic concepts of the phenomenon of Tl are described and those are explained characteristic of the deconvolution method to determine the kinetics of the one phenomenon. In the Chapter 4, the methodology is detailed that was used in the elaboration of this thesis work, describing the material Tl that were considered like reference, as well as the sources of ionizing radiation, with those that the dosemeters were irradiated and the equipment in the one that the curves Tl was obtained. Reference is made to the software used to carry out the deconvolution of the curves Tl that were obtained in the one experimental development. In the Chapter 5, the obtained results of this study are presented, showing the tables of homogenization of dosemeters and the reading of the same one; they are observed the curves Tl obtained to different radiation doses (alpha, beta and gamma), the intensity Tl in function of the dose. Also they are tabulated, the obtained results in the kinetic parameters of the three different study materials (TLD-100H, USA; TLD-100, USA and LiF: Mg, Cu, P + Ptfe developed in the l.N.l.N). They are analyzed shortly for each material Tl their sensitivity to the ionizing radiation as well as their kinetic parameters. The obtained results showed that the Tl dosemeters of LiF: Mg,Cu,P + Ptfe, they presented a bigger sensitivity that the TLD-100 when

  9. Proton/gamma relative thermoluminescence efficiencies of LiF:Mg,Cu,P+PTFE prepared at ININ and TLD-100H

    Energy Technology Data Exchange (ETDEWEB)

    Avila, O.; Gonzalez, P.; Murillo, G. [Departamento de Fisica, ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2009-10-15

    Properties of LiF:Mg,Cu,P+PTFE dosemeters developed at ININ have been investigated in order to evaluate their performance compared to those of equivalent commercial dosemeters. In this work both LiF:Mg,Cu,P+PTFE and TLD-100H pellets were exposed to low fluence 3 MeV protons and to low dose gamma radiation to evaluate experimental proton/gamma efficiencies. Gamma irradiation was performed using the Vic krad irradiator at ININ at varying doses between 25 and 500 mGy. For proton irradiation the Tandem Van de Graaff accelerator at ININ was used. Dosemeters were placed on a holder inside a scattering chamber where protons impinge on a gold target and scatter in all directions. The holder allows for several angular positions so that dosemeters receive proton fluence between 10{sup 6} and 10{sup 1}0 p/cm{sup 2}. Experimental efficiency values found for LiF:Mg,Cu,P+PTFE and TLD-100H were 0.18 +- 03 and 0.23 +- 0.03, respectively. These results allow to confirm the reliability of the dosemeters developed at ININ. (Author)

  10. Optimizing the TLD-100 readout system for various radiotherapy beam doses using the Taguchi methodology

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.Y. [School of Medical Imaging Technology, Chung Shan Medical University, Taichung 402, Taiwan (China); Liu, K.C.; Chen, H.H. [Graduate Institute of Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan (China); Pan, L.K. [Graduate Institute of Radiological Science, Central Taiwan University of Science and Technology, Takun, Taichung 406, Taiwan (China)], E-mail: lkpan@ctust.edu.tw

    2010-03-15

    The TLD-100 readout system was optimized for various radiotherapy beam doses using the Taguchi method. The radiotherapy beam was produced by a Varian 21EX linear accelerator (LINAC) at 6 MV. The beam doses were 50, 100 and 150 cGy, and the measured data in each group were averaged from three TLD-100 chips. A total of nine combinations of four parameters were arranged, in the manner suggested by Taguchi. The four parameters were defined as initial temperature, heating rate, preheat time and maximum set temperature of the readout system during TLD reading. The loss function {eta} adopted herein was specifically defined to satisfy the requirements of both sharp linearity and good reproducibility of the TLD reading at various radiotherapy beam doses. The optimized values were: (1) 50 deg. C for initial temperature, (2) 3 deg. C/s for heating rate, (3) 5 min for the TLD preheat time and (4) 250 deg. C for the maximum temperature for TLD reading. Additionally, the parameters that dominated the TLD readout were: (1) initial temperature, (2) heating rate and (4) maximum temperature setting for TLD reading; and the minor parameter was (3) TLD preheat time before reading. The interactions among the dominant parameters were also studied: no significant cross interaction occurred between initial temperature and heating rate or between initial temperature and maximum temperature. However, a complex cross-interaction existed between optimal heating rate and maximum temperature.

  11. Thermoluminescence Study of Gamma Irradiated Cr-Doped LiF Phosphors

    Science.gov (United States)

    Kumar, Satinder; Gathania, A. K.; Vij, Ankush; Kumar, Ravi

    2016-06-01

    We have synthesized Cr-doped LiF phosphors by using modified co-precipitation. X-ray diffraction study confirms the single-phase cubic structure up to 0.05 mol.% of Cr in LiF; afterwards, a secondary phase of formation was observed. The field emission scanning electron microscope (FESEM) images revealed micro-cubic surface morphology of samples. The thermoluminescent (TL) behavior of the samples studied after irradiating them with gamma rays in the dose range 0.1-30 kGy. The TL glow curve of Cr-doped LiF comprises a prominent peak observed at 407 K and a broad band ranging from 448 K to 512 K at a fixed gamma dose of 10 kGy. The shape of the TL glow curve remained similar at all concentrations of Cr in LiF; however, TL intensity was found to vary with Cr concentration, and Cr (0.02 mol.%)-doped LiF sample exhibit highest TL response. The glow curve of the optimized sample as a function of gamma irradiation dose within the range 0.1-30 kGy shows an almost linear increase in TL intensity of the main glow peak up to 10 kGy, and afterwards it decreases. Further, at the high dose of 30 kGy, the intensity of the prominent TL glow peak at 407 K decreases and another broad peak starts growing at 468 K signifying the formation of new trapping sites. The kinetic parameters, namely activation energy, order of kinetics, and frequency factor of the optimized sample were evaluated by using Chen's peak shape method and glow curve deconvolution (GCD) functions based on Kitti's equations.

  12. Thermoluminescence of gamma rays irradiated LiF nanocubes doped with different elements

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Department of Aeronautical Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-05-15

    Lithium fluoride (LiF) doped with proper activator is a highly sensitive phosphor, widely used as a dosimeter for ionizing radiations. This work reports on the thermoluminesence (TL) response of LiF nanocubes doped with different impurities. These nanocubes were synthesized by the co-precipitation method and characterized by different techniques. The dopants used in this study are Eu, Tb, Dy, Cu and Ag. The gamma radiation induced TL glow peaks are located in the temperature range 120–125 °C. These samples have different TL sensitivities, where Eu doped one is found to be the most TL sensitive. Further irradiations in the dose range from 10 Gy to 30 kGy were performed to LiF:Eu and the obtained result is explained using a proposed multilevel TL model. According to this model, Eu dopant (in Eu{sup 3+} ionic form) could induce shallow and deep electron traps in the host of LiF nanocubes. These traps differ in their response according to the doses. The optimum concentration of Eu ions in LiF host is found to be 0.2 mol%. It is also found that LiF nanocubes are thermally stable in the range of 30–400 °C with a single phase. This property along with the good sensitivity of Eu doped one makes this tissue equivalent nanomaterial a proper candidate for heavy dose measurement like swift heavy ions used in radiotherapy. - Highlights: • Nanocubes of pure and doped LiF were produced by the co-precipitation method. • They were doped with Eu, Tb, Dy, Cu and Ag and studied for their TL response. • The gamma radiation induced TL glow peaks are located in the range 120–125 °C. • The Eu doped one is found to be the most TL sensitive, followed by Tb. • The tissue equivalent LiF:Eu nanocubes might be useful for heavy dose measurement.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  14. Tl response of LiF:Mg, Cu, P + PTFE to Am-Be neutrons; Respuesta Tl de LiF: Mg, Cu, P + PTFE a neutrones de Am-Be

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    In different laboratories of the world it is followed the research about development of new Tl materials, whose main characteristics should be their equivalence with the tissue and their high sensibility to any type of radiation. The study consists in to measure the Tl peak intensity which TLD-100 presents at being irradiated with neutrons and that appears over 250 Centigrade, for compare it with the Tl intensity of the LiF: Mg, Cu, P + PTFE dosemeters. However, not all dosemeters of the same group show the interesting peak, by this only can be the total Tl intensity of dosemeters studied. In the ININ dosemeters development laboratory, we have developed a Tl material of lithium fluoride activated with magnesium, copper and phosphorus (LiF: Mg, Cu, P) that in polycrystalline powder form is almost 35 times more sensitive than the TLD-100 commercial dosemeter of Harshaw/Filtrol, USA. With the use of polytetrafluorethylene (PTFE) and with the above described Tl material, it has been possible to obtain dosemeters in pellet form of LiF: Mg, Cu, P + PTFE. (Author)

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

    CERN Document Server

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

    2002-01-01

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

  16. Stability of the post irradiation traps in LiF: Mg, Cu, P; Estabilidad de las trampas posradiacion en LiF: Mg, Cu, P

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Furetta, C. [Physics Department, Rome University ' ' La Sapienza' ' , Rome (Italy); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the results of the study of the stability of the traps are presented in dosemeters Tl of LiF: Mg,Cu,P, irradiated with gamma radiation of {sup 60} Co. The studied dosemeters were of LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese manufacture. Before being exposed to the radiation, the dosemeters received their standard treatment from having erased, two hours after the irradiation they took the initial readings. The dosemeters faded again and they were irradiated to the same dose, soon after they stayed under normal conditions, protected of the light, later on they were taken their readings periodically during six months. The readings taken Tl the same day of the irradiation presented four peaks whose energy, determined by the deconvolution method were; 1.30 {+-} 0.01 eV, 1.50 {+-} 0.01 eV, 1.70 {+-} 0.01 eV and 2.58 {+-} 0.02 eV, for LiF: Mg,Cu,P + Ptfe, while GR200A stops the energy they were: 1.33 {+-} 0.11 eV, 1.58 {+-} 0.11 eV, 1.73 {+-} 0.11 eV and 2.60 {+-} 0.03 eV. In both cases the peak 1, with the energy but it lowers, it disappears completely after some later hours to the irradiation, while the peak 2, it disappears completely after 122 days for the local dosemeter and after 94 days for the commercial dosemeter. The energy of the peaks 3 and 4 that remained visible during the whole period of study it was: 1.38 {+-} 0.01 eV and 2.65 {+-} 0.01 eV, for LiF: Mg,Cu,P + Ptfe respectively, in the same order for GR200A, the energies were: 1.51 {+-} 0.02 eV and 2.64 {+-} 0.03 eV. In all the cases the peaks with energy below 2 eV, showed tendency to the drop, while the main peak, showed certain tendency to increase, as they show it the results. (Author)

  17. Dosimetric evaluation of the response of the TLD-100 dosemeters in the IMRT technique by 'Step and Shoot'; Evaluacion dosimetrica de la respuesta de los dosimetros TLD-100 en la tecnica de IMRT por 'Step and Shoot'

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, J. [Fundacion Clinica Valle del Lili, A.A. 020338, Cali (Colombia); Benavides, S.O. [Depto. de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)

    2005-07-01

    We show the results of the dosimetry response of LiF thermoluminescent crystals: TLD-100, where they were radiated in a linear accelerator Siemens Primus Hl using the Intensity Modulated Radiation Therapy (IMRT) by step and shoot technique. Previous to the crystals calibration and response evaluation, the acceptation procedures recommended by the TG-53 protocol for validation of the technique were carried out. The planning system utilized was the Theraplan Plus 3.8, using the algorithm of Pencil Kernel. The register and verification system was Lantis 5.2. The response curve of dose versus charge was obtained from the readings of the TLD in a Harshaw 3500. The crystals were radiated in a Bench- Marck phantom with doses previously determined by using ionization chambers for square radiation fields, in a beam with a 0.68 TPR20,10 corresponding to 6 MV of energy. We compare the response of these through of radiation of segmented fields in a Anthropomorphic phantom and the calculated doses by the planning system. The results obtained in the crystals response show deviations less than 5 % between the measured dose and the calculated dose in the zones of low gradient. It allows its implementation like routine control of quality by IMRT. (Author)

  18. Comparison of the responses of TLD-100 and radiochromic films exposed to X-rays of low energy in a radiodiagnostic clinical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Castro, M.; Mesa, F.; Sosa, M. [Physics Institute, University of Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2007-07-01

    Full text: In this work a comparison of the responses of a TLD-100 and a radiochromic film exposed to a low energy X-ray beam is presented. X-rays in the range of 20 to 120 KV from a clinical machine at the radiodiagnostic unit of the IMSS-Tl hospital in Leon were used. The processes of calibration of both the TLD-100 and the radiochromic films are also discussed. (Author)

  19. Evaluation of The Combined Effects of Hyperthermia, Cobalt-60 Gamma Rays and IUdR on Cultured Glioblastoma Spheroid Cells and Dosimetry Using TLD-100

    Directory of Open Access Journals (Sweden)

    Ali Neshasteh-Riz

    2014-04-01

    Full Text Available Objective: In radiation treatment, the irradiation which is effective enough to control the tumors far exceeds normal-tissues tolerance. Thus to avoid such unfavourable outcomes, some methods sensitizing the tumor cells to radiation are used. Iododeoxyuridine (IUdR is a halogenated thymidine analogue that known to be effective as a radiosensitizer in human cancer therapy. Improving the potential efficacy of radiation therapy after combining to hyperthermia depends on the magnitude of the differential sensitization of the hyperthermic effects or on the differential cytotoxicity of the radiation effects on the tumor cells. In this study, we evaluated the combined effects of IUdR, hyperthermia and gamma rays of 60Co on human glioblastoma spheroids culture. Materials and Methods: In this experimental study,the cultured spheroids with 100μm diameter were treated by 1 μM IUdR, 43˚C hyperthermia for an hour and 2 Gy gamma rays, respectively. The DNA damages induced in cells were compared using alkaline comet assay method, and dosimetry was then performed by TLD-100. Comet scores were calculated as mean ± standard error of mean (SEM using one-way ANOVA. Results:Comparison of DNA damages induced by IUdR and hyperthermia + gamma treatment showed 2.67- and 1.92-fold enhancement, respectively, as compared to the damages induced by radiation alone or radiation combined IUdR. Dosimetry results showed the accurate dose delivered to cells. Conclusion: Analysis of the comet tail moments of spheroids showed that the radiation treatments combined with hyperthermia and IUdR caused significant radiosensitization when compared to related results of irradiation alone or of irradiation with IUdR. These results suggest a potential clinical advantage of combining radiation with hyperthermia and indicate effectiveness of hyperthermia treatment in inducing cytotoxicity of tumor cells.

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

    Energy Technology Data Exchange (ETDEWEB)

    Flores M, E. [UNAM, Facultad de Ciencias, 04510 Mexico D.F. (Mexico)

    2007-07-01

    The increase of the applications of ion beams in radiotherapy treatments has generated interest in the study of the thermoluminescent materials (TL) that allow to determine the applied doses. A way to quantify the TL response from these materials to ions is by means of the relative thermoluminescent efficiency. In the group of Thermoluminescent dosimetry of the Institute of Physics of the UNAM (IFUNAM) the thermoluminescent response of the TLD-100 dosemeters has been studied, which present a glow curve characteristic with several peaks that correspond to traps and luminescent centers in the material. The stable peaks know each other as 4, 5, 6a, 6b, 7, 8, 9 and 10. The efficiencies should be measured using the response so much to the radiation of interest (in this case protons and helium ions) as the response to gamma radiation. In previous works with ions of low energy taken place in the Pelletron accelerator of the IFUNAM was only measured the TL efficiency for the peak 5 and the total signal. It had not been possible to measure the efficiency of the peaks of high temperature (6a-10) because, for the gamma radiation, the peaks of high temperature show very small signals; however, recently Massillon carries out measures of efficiency TL of peaks of high temperature for ions of intermediate energy using a protocol special of reading and of deconvolution that allows to measure the signals coming from the peaks of high temperature. In this work is implemented this same protocol to complete the study of TL efficiencies at low energy of protons and helium and to determine if the values of efficiency depend on the used reading protocol. For it is reported it measures of the relative efficiency of the peaks of high temperature from the TLD-100 exposed to protons of 1.5 MeV and nuclei of helium of 3 and 7.5 MeV. (Author)

  1. Relationship between electromagnetic and acoustic emissions during plastic deformation of gamma-irradiated LiF monocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Hadjicontis, V.; Mavromatou, C.; Mastrogiannis, D. [Department of Solid State Physics, University of Athens, Panepistimiopolis, Zografos, TK 157 84, Athens (Greece); Antsygina, T. N.; Chishko, K. A. [B. Verkin Institute for Low Temperature Physics and Engineering, 47 Lenin Ave., 61103 Kharkov (Ukraine)

    2011-07-15

    Simultaneous measurements of acoustic emissions (AE) and electromagnetic emissions (EME) during plastic deformation and destruction under uniaxial compression along <001> direction are made on LiF monocrystals after gamma irradiation by {sup 60}Co source. The irradiation doses are 1, 2, and 10 Mrad. The EME measurements in the radio-frequency range are carried out using two types of electromagnetic sensors: (i) a simple electrical stub antenna and (ii) a toroidal inductance coil. Two checking experiments on unirradiated crystals are performed as the starting point to discover the effect of gamma irradiation on acoustic and electromagnetic emissive ability of plastically deformed ionic crystals. Unirradiated LiF monocrystals demonstrate high-intensive EME at easy glide and work hardening stages, as well as at the fracture during destruction of the sample. At radiation doses more than {approx}1 Mrad, in the active loading stage the EME of LiF monocrystals vanishes, except few individual electromagnetic pulses (only at 1 and 2 Mrad doses), which are time correlated with well-defined drop-jumps on the loading diagram and therefore can be associated with macroscopic crack openings. Moderate electromagnetic activity in irradiated crystals occurs only in the final stage of deformation at the complete fracture of the sample. Thus, after gamma irradiation the formation of polarization currents due to dynamic interaction between charged vacancies and moving dislocations is suppressed, and only EME connected with the redistribution of the free charge on the crack branches is observed. Acoustic emission diagrams of low-irradiated LiF are typical for the work hardening stage in crystals containing a great amount of strong point stoppers. At larger irradiation doses the AE diagram displays quite different behavior at low- and high-loading regions with a sharp boundary between them. The low-loading region shows poor AE activity, which changes sharply into high-active burst

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-22

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

  3. Fading of the Tl signal in LiF: Mg, Cu, P during a large post irradiation period; Desvanecimiento de la senal Tl en LiF: Mg, Cu, P durante un largo periodo posradiacion

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universidad de Roma, Piazzale Aldo Moro 2, Roma (Italy)

    2004-07-01

    In this work the obtained results of the study of the fading of the Tl signal in dosemeters of LiF activated with magnesium, copper and phosphorus (LiF:Mg,Cu,P) are presented. The studied dosemeters were LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese manufacture. In both cases the Tl curve presents four peaks; in LiF: Mg,Cu,P + Ptfe, the peaks of smaller size appear in 359 K, 389 K and 447 K, the main dosimetric peak appears in 486 K; in GR200A, the peaks of smaller size appear in 360 K, 389 K and 445 K; while the main dosimetric peak appears in 487 K. The highest fading shown by the dosemeters of LiF: Mg,Cu,P + Ptfe, it was of 3.07%, value very below the one recommended for dosimetric purposes. While the commercial dosemeters presented a fading until of 6.23%, surpassing with the recommended values. The observed fading, it corresponds to the lost of the Tl signal of the peaks 1 and 2, since the first one disappears few hours after the irradiation, while the peak 2, it disappears completely after 94 days, the peak 3 remained stable during the six months of study, while the peak 4, it showed a slight increment due to the contribution of the dose of natural environmental radiation. (Author)

  4. TL response of Eu activated LiF nanocubes irradiated by 85 MeV carbon ions

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Numan, E-mail: nsalah@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alharbi, Najlaa D. [Sciences Faculty for Girls, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Habib, Sami S. [Center of Nanotechnology, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Lochab, S.P. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-09-01

    Carbon ions were found to be effective for cancer treatment. These heavy ions have a high relative biological effectiveness compared to those of photons. They have higher linear energy transfer and sharper Bragg peak with a very excellent local tumor control. However, the dose of these swift heavy ions needs to be measured with great accuracy. Lithium fluoride (LiF) is a highly sensitive phosphor widely used for radiation dosimetry. In this work Eu activated LiF nanocubes were exposed to 85 MeV C{sup 6+} ion beam and evaluated for their thermoluminescence (TL) response. Pellet forms of this nanomaterial were exposed to these ions in the fluence range 10{sup 9}–10{sup 13} ions/cm{sup 2}. The obtained result shows a prominent TL glow peak at around 320 °C, which is different than that induced by gamma rays. This glow peak exhibits a linear response in the range 10{sup 9}–10{sup 12} ions/cm{sup 2}, corresponding to the equivalent absorbed doses 0.273–273 kGy. The absorbed doses, penetration depths and main energy loss were calculated using TRIM code based on the Monte Carlo simulation. The supralinearity function and stopping power in this nanomaterial were also studied. The modification induced in the glow curve structure as a result of changing irradiation type might be utilized to use LiF:Eu nanocubes as a dosimeter for mixed filed radiations. Moreover, the wide linear response of LiF:Eu nanocubes along with the low fading are another imperative results suggesting that this nanomaterial might be a good candidate for carbon ions dosimetry.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  6. Preliminary assessment of LiF and alanine detectors for the dosimetry of proton therapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Fattibene, P.; Calicchia, A.; De Angelis, C.; Onori, S. [Istituto Superiore di Sanita, Rome (Italy)]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy). Sezione Sanita; d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari]|[Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Egger, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    An experimental intercomparison between the proton response of LiF TLD-100 and alanine detectors is reported. The investigations were performed with LiF chips and alanine pellets in a 62 MeV proton beam at the Paul Scherrer Institut in Villigen (CH). Results were compared with reference dosimetry provided by Markus type parallel plate ionization chamber. The response of the detectors was studied, in a phantom, at different beam penetration depths in pristine and modulated beams. For both alanine and TL detectors, within the experimental uncertainty of the measurements, no significant energy dependence in the response was observed down to the Bragg peak region. The sensitivity of alanine and LiF detectors to protons was measured in the centre of modulated Bragg peak and no significant difference was found with respect to {sup 60}Co. Contrary to LiF, alanine also offers a remarkable tissue equivalence which favours its choice for in-phantom dosimetry. (author).

  7. Tl response of LiF: Mg, Cu, P+Ptfe at X rays of 24, 42 and 100 KeV; Respuesta TL de LiF: Mg, Cu, P+Ptfe a rayos X de 24, 42 y 100 KeV

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R.; Tovar M, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma (Italy); Quiroz C, M.C. [Facultad de Medicina, UAEM, 50180 Toluca, Estado de Mexico (Mexico)

    2005-07-01

    In this work the obtained results of the irradiation of thermoluminescent dosemeters (Tl) of LiF: Mg,Cu,P + Ptfe with X rays for the effective radiation energy of 24, 42 and 100 keV, in an interval of Kerma in air in the sinus of the air between 0.05 and 1.0 Gy are presented. The rate of Kerma in air was determined with an ionization chamber PTW-1152, gauged by the Laboratoire Central des Industries Electriques (LCIE). As reference commercial TLD-100 dosemeters was used. The results showed that the studied Tl dosemeters presented a lineal response in the interval of mentioned Kerma. On the other hand the estimated Kerma with the Tl dosemeter in the calibration curves for X rays, were similar to the one measured with the previously gauged ionization chamber. The Tl of LiF: Mg, Cu, P + Ptfe, developed in the ININ, are highly reliable for X-ray dosimetry. (Author)

  8. Mysteries of LiF TLD response following high ionisation density irradiation: nanodosimetry and track structure theory, dose response and glow curve shapes.

    Science.gov (United States)

    Horowitz, Y; Fuks, E; Datz, H; Oster, L; Livingstone, J; Rosenfeld, A

    2011-06-01

    Three outstanding effects of ionisation density on the thermoluminescence (TL) mechanisms giving rise to the glow peaks of LiF:Mg,Ti (TLD-100) are currently under investigation: (1) the dependence of the heavy charged particle (HCP) relative efficiency with increasing ionisation density and the effectiveness of its modelling by track structure theory (TST), (2) the behaviour of the TL efficiency, f(D), as a function of photon energy and dose. These studies are intended to promote the development of a firm theoretical basis for the evaluation of relative TL efficiencies to assist in their application in mixed radiation fields. And (3) the shape of composite peak 5 in the glow curve for various HCP types and energies and following high-dose electron irradiation, i.e. the ratio of the intensity of peak 5a to peak 5. Peak 5a is a low-temperature satellite of peak 5 arising from electron-hole capture in a spatially correlated trapping centre/luminescent centre (TC/LC) complex that has been suggested to possess a potential as a solid-state nanodosemeter due to the preferential electron/hole population of the TC/LC at high ionisation density. It is concluded that (1) the predictions of TST are very strongly dependent on the choice of photon energy used in the determination of f(D); (2) modified TST employing calculated values of f(D) at 2 keV is in agreement with 5-MeV alpha particle experimental results for composite peak 5 but underestimates the 1.5-MeV proton relative efficiencies. Both the proton and alpha particle relative TL efficiencies of the high-temperature TL (HTTL) peaks 7 and 8 are underestimated by an order of magnitude suggesting that the HTTL efficiencies are affected by other factors in addition to radial electron dose; (3) the dose-response supralinearity of peaks 7 and 8 change rapidly with photon energy: this behaviour is explained in the framework of the unified interaction model as due to a very strong dependence on photon energy of the relative

  9. Characterization of TLD-100 in powders for dosimetric quality control of {sup 192} Ir sources used in brachytherapy of high dose rate; Caracterizacion de TLD-100 en polvo para control de calidad dosimetrico de fuentes de Ir{sup 192} usadas en braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P

    2007-07-01

    The Secondary Standard Dosimetric at the National Institute of Nuclear Research (ININ) calibrated a lot of powdered TLD-100 (LiF:Mg,Ti) in terms of absorbed dose to water D{sub w} for the energy of: {sup 60}Co, {sup 137C}s, X rays of 250 and 50 kVp. Later on, it is carried out an interpolation of the calibration for the energy of the {sup 192}Ir. This calibration is part of a dosimetric quality control program, to solve the problems of traceability for the measurements carried out by the users of {sup 192}Ir sources employed in the treatments of High Dose Rate Brachytherapy (HDR) at the Mexican Republic. The calibrations of the radiation beams are made with the following protocols: IAEA TRS-398 for the {sup 60}Co for D{sub w}, using a secondary standard ionization chamber PTW N30013 calibrated in D{sub w} by the National Research Council (NRC, Canada). AAPM TG-43 for D{sub w} in terms of the strength kerma Sk, calibrating this last one quantity for the {sup 137}Cs radioactive source, with a well chamber HDR 1000 PLUS traceable to the University of Wisconsin (US). AAPM TG-61 for X ray of 250 and 50 kVp for D{sub w} start to Ka using field standard a Farmer chamber PTW 30001 traceable to K for the Central Laboratory of Electric Industries (CLEI, France). The calibration curves (CC) they built for the response of the powder TLD: R{sub TLD} vs D{sub w}: For the energy of {sup 60}Co, {sup 137}Cs, X rays of 250 and 50 kVp. Fitting them with the least square method weighed by means of a polynomial of second grade that corrects the supra linearity of the response. iii. Each one of the curves was validated with a test by lack of fitting and for the Anderson Darling normality test, using the software MINITAB in both cases. iv. The sensibility factor (F{sub s}) for each energy corresponds to the slope of the CC, v. The F{sub s} for the two {sup 192}Ir sources used are interpolated: one for a Micro Selectron source and the other one a Vari Source source. Finally, a couple of

  10. Measurement of the Dose to the Family Members Taking Care of Thyroid Cancer Patients Undergoing I-131 Therapy in Nuclear Medicine Using TLD-100.

    Science.gov (United States)

    Zehtabian, M; Dehghan, N; Danaei Ghazanfarkhani, M; Haghighatafshar, M; Sina, S

    2017-05-01

    The family members or friends of the patients undergoing treatment using radioiodine in nuclear medicine are inevitably exposed to ionization radiation. The purpose of this study is measurement of the dose received by the people taking care of the thyroid cancer patients treated by 131I. For this purpose, the dose amounts received by 29 people accompanying patients were measured using thermoluminescence dosimeters. A badge containing three TLD-100 chips was given to each caregiver. The people were asked to wear the badges for 24 days, when they are taking care of the patients. Finally the dose to each person was estimated by averaging the readings of the three TLDs. The measured dose amounts to the people were compared with the recommendations of international commitions. According to the results obtained in this study, the amounts of dose received by the caregivers were between 0.03 and 0.38 mSv, with the average of 0.12 mSv. By comparison of the results of this study with the recommendations of International Commission on Radiological Protection (ICRP), it can be observed that the dose to family members of the patients is less than the dose constraints. However, it is recommended that the caregivers be aware of the radiation protection principles in order to reduce their dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Production of LiF films for dosimetric thermoluminescence application; Producao de filmes de LiF para aplicacao em dosimetria termoluminescente

    Energy Technology Data Exchange (ETDEWEB)

    Mauricio, Claudia Lucia de Pinho

    2000-12-01

    This work studies the LiF monolayer and multilayer polycrystalline film's dosimetric properties. The films were produced by electron beam evaporation technique in aluminium and stainless steel substrates maintained at several temperatures. As dosimetric variable, the intensity of the thermoluminescent (TL) glow curve of the films was used. effects of the substrate type and temperature; of the addition of layers of Mg F{sub 2} NaF and Cu F{sub 2} to the LiF films; and of thermal treatments in the TL response of the produced films were studied. The microstructural characterization of the films was accomplished through measures of scanning electronic microscopy and grazing incidence X-rays diffraction analysis. The dosimetric characterization was made of gamma radiation exposure in a {sup 60} Co source, with kerma from 0,1 to 500 Gy. Studies of reproducibility, homogeneity, stability and other environmental effects were also made. LiF and Cu F{sub 2}: LiF; Mg F{sub 2} films were the only ones that presented mechanical stability and reproducibility of the TL emission. There is a strong indication of some correlation between the residual tension fields inside the films and the intensity of its TL emission peaks. LiF monolayer films present supralinear behaviour from 0,2 to 100 Gy. These films present a main TL glow peak around 150 deg C, whose half-time is about 30 days. Its volumetric sensitivity can reach about 60 times that of LiF powder and about 0,25 that of TLD100 (LiF:Mg, Ti commercial dosimeter from Harshaw Chemical Co.) The homogeneity and reproducibility inside a same film batch is better than 12% for 95% confidence level. Cu F{sub 2} : LiF: Mg F{sub 2} films present linear behaviour from 3 to 500 Gy and its main TL glow peak around 200 deg C did not present any fading for a a period of 30 days, in laboratory conditions. This glow peak is characteristic of the Mg doping of LiF, which confirms the diffusion of Mg ions from the Mg F{sub 2} layer to the LiF

  12. ON HF (TLD -100) PHOSPHORS

    African Journals Online (AJOL)

    2005-08-19

    Aug 19, 2005 ... Department of Physics and Solar Energ/, Bowen University, Two, Nigeria ... annealing at higher temperatures for longer length of time appears to improve the sensitivity of the ... reported that it was sublinear at low dose;.

  13. Mensuration of equivalent dose with personal dosemeters and instruments of radiological protection in the new operative quantities ICRU, for external fields of beta radiation. Part II. I study of the angular response of personal dosemeters TLD-100 in secondary patron fields of beta radiation ({sup 90}Sr / {sup 90}Y); Medicion de dosis equivalente con dosimetros personales e instrumentos de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion beta externos. Parte II. Estudio de la respuesta angular de dosimetros personales TLD-100 en campos patrones secundarios de radiacion beta ({sup 90}Sr/{sup 90}Y)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-01-15

    The objective of this work is to carry out one of the possible ones test type for personal dosemeters TLD, under the recomendations of the ICRU 39, ICRU 43 and the draft of the norm ISO 6980,(1992), with the purpose of verifying the capacity of these detectors to carry out the operative unit: H' (0.07;{alpha}). Since H' (O. 07;{alpha}) this defined one in an expanded field, one of these tests type consist on determining the angular response of these detectors. 20 personal dosemeters TLD-100 was used, (card marks: Harshaw, Model: G-1, with two glasses of TLD-100 absorbed in teflon; the portadosemeters has two windows, a free one and another with a filter of Pb of 171.0 mg cm{sup -2}); these dosemeters they were previously selected, [to see, {sup S}tudy of the Homogeneity of the response of Personal Dosemeters (Cards G-l, TLD-100) in Radiation of Countrysides of {sup 60}Co{sup ,} J.T. Alvarez R. Technician Report GSR/IT/0001/94].The irradiations to effectued in secondary countryside of radiation beta of {sup 90}Sr/{sup 90}Y. The study was undertaken by means of an experimental design of blocks random that contemplate the following variables: intensity of the radiation source, (1850 MBq and 74 MBq); position of irradiation, (four positions); incidence of angle of the radiation (0, 15, 30, 45, 60 and 75 grades) and the absorbed dose in air, (0.005, 0.010, 0.020, 0.050 and 0.100 Gy). Then null hypothesis it was to suppose that there was not difference among the stockings of each treatment, to used the statistical of Duncan to carry out tests of stockings at a level of significance of 5%.These tests of stockings throw the following results in those variables of the experimental design: The irradiations carried out so much with the source pattern secondary of {sup 90}Sr/{sup 90}Y of 1850 MBq and of 74 MBq, they are equivalent reason why they can be used indistinctly. The responses of each one of the glasses of the card are strongly anisotropic for each glass

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-15

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

  15. Dosimetry for small fields in stereotactic radiosurgery using gafchromic MD-V2-55 film, TLD-100 and alanine dosimeters.

    Directory of Open Access Journals (Sweden)

    Guerda Massillon-J L

    Full Text Available This work investigated the suitability of passive dosimeters for reference dosimetry in small fields with acceptable accuracy. Absorbed dose to water rate was determined in nine small radiation fields with diameters between 4 and 35 mm in a Leksell Gamma Knife (LGK and a modified linear accelerator (linac for stereotactic radiosurgery treatments. Measurements were made using Gafchromic film (MD-V2-55, alanine and thermoluminescent (TLD-100 dosimeters and compared with conventional dosimetry systems. Detectors were calibrated in terms of absorbed dose to water in (60Co gamma-ray and 6 MV x-ray reference (10×10 cm(2 fields using an ionization chamber calibrated at a standards laboratory. Absorbed dose to water rate computed with MD-V2-55 was higher than that obtained with the others dosimeters, possibly due to a smaller volume averaging effect. Ratio between the dose-rates determined with each dosimeter and those obtained with the film was evaluated for both treatment modalities. For the LGK, the ratio decreased as the dosimeter size increased and remained constant for collimator diameters larger than 8 mm. The same behaviour was observed for the linac and the ratio increased with field size, independent of the dosimeter used. These behaviours could be explained as an averaging volume effect due to dose gradient and lack of electronic equilibrium. Evaluation of the output factors for the LGK collimators indicated that, even when agreement was observed between Monte Carlo simulation and measurements with different dosimeters, this does not warrant that the absorbed dose to water rate in the field was properly known and thus, investigation of the reference dosimetry should be an important issue. These results indicated that alanine dosimeter provides a high degree of accuracy but cannot be used in fields smaller than 20 mm diameter. Gafchromic film can be considered as a suitable methodology for reference dosimetry. TLD dosimeters are not

  16. Application of the Cavity theory in the calibration of the powder TLD-100 for energies of {sup 60} Co, {sup 137} Cs, {sup 192} Ir and RX 50, 250 k Vp; Aplicacion de la Teoria de la Cavidad en la calibracion de polvo TLD-100 para energias de {sup 60} Co, {sup 137} Cs, {sup 192} Ir y RX 50, 250 kVp

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P. [UAEM, Programa de Maestria en Fisica Medica, 50180, Toluca, Estado de Mexico (Mexico); Alvarez R, J.T. [ININ, 52750, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: sandraplc_04@yahoo.com.mx

    2006-07-01

    A powder lot TLD-100 (LiF:Mg,Ti) in absorbed dose terms in water D{sub w} for the following radiation sources: {sup 60} Co, {sup 137} Cs and RX 50 and 250 k Vp is calibrated; to continuation is made a lineal interpolation of the TLD response in function of the effective energy of the sources to calibrate a source of {sup 192} Ir. The calibration of those fields in D{sub w} are carried out with aid of the Bragg-Gray cavity theory, the one which finds implicit in the following protocols: IAEA-TRS 398 for the {sup 60} Co and the AAPM TG61 for X Rays of 50 and 250 k Vp. Additionally the AAPM protocol TG43 to determine the D{sub w} in function of the kerma intensity S{sub k} in the case of the {sup 137} Cs is used. The calibration curves for the response of the TLD-100 R{sub TLD} vs D{sub w}, corresponding to each one of the sources already mentioned are constructed. The R{sub TLD} vs D{sub w} by least heavy square by means of a second order polynomial that corrects the supralineality of the response is adjusted. The curves are validated by lack of LOF adjustment and by the Anderson Darling normality test. Later the factors of sensitivity (F{sub s}) for the sources of {sup 192} Ir: Micro Selectron and Vari Source are interpolated, used respectively in the A and B hospitals for treatments of brachytherapy of high dose rate (HDR), the expanded uncertainties associated to the D{sub w} and F{sub s} are also determined. Finally, an acrylic phantom and a couple of capsules are already sent to the hospitals mentioned, to verify a nominal D{sub w} of 2 Gy, in a case an underestimate in 5.5% in the imparted D{sub w} and in other an overestimation in a range of -1.5 to -8.0% was obtained. The obtained results in this work establish the bases for the development of a national dosimetric quality control program for brachytherapy of HDR with sources of {sup 192} Ir. (Author)

  17. Calibration of TLD-100 powder for energies of {sup 60} Co, {sup 137} Cs, {sup 192} Ir and RX of 250, 50 kV{sub p} in absorbed dose in water with dosimetric quality control purposes for brachytherapy of high dose rate; Calibracion de polvo TLD-100 para energias de {sup 60} Co, {sup 137} Cs, {sup 192} Ir y RX de 250, 50 kVp en dosis absorbida en agua con fines de control de calidad dosimetrico para braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P. [Programa de Maestria en Fisica Medica, Universidad Autonoma del Estado de Mexico, Paseo Tollocan S/N, esquina con Jesus Carranza, Colonia Moderna de la Cruz, 50180 Toluca, Edo. de Mexico (Mexico); Alvarez R, J.T. [Laboratorio Secundario de Calibracion Dosimetrica LSCD, Departamento de Metrologia, ININ, Carretera Federal Mexico Toluca S/N, La Marquesa, 52750 Ocoyoacac, Edo. de Mexico (Mexico)

    2006-07-01

    To help solve the traceability and quality control dosimetric problems for the users of {sup 192} Ir sources in the Mexican Republic, the Secondary Standard Dosimetric Laboratory at ININ to calibrated a batch of powder TLD- 100 (LiF: Mg,Ti) in terms of absorbed dose to water D{sub w} for the following radiation sources: {sup 60} Co, {sup 137C}s and RX 250 and 50 k Vp. Later on, the calibration is interpolated to obtain the {sup 192} Ir. The calibration radiation field is carried out with the following protocols: For the {sup 60} Co, IAEA TRS 398 protocol employing a secondary standard Farmer chamber PTW N30013, calibrated on D{sub w} at the NRC (Canada). For {sup 137} Cs the AAPM TG 43 protocol is used, in terms of air kerma strength S{sub k} determined by the air kerma K{sub a}, measured with a secondary standard chamber type thimble NE2611 traceable to the NIST (USA). For Rays X 250 and 50 k Vp, the protocol AAPM TG 61 using a tertiary standard Farmer chamber PTW 30001, with traceability to the LCIE (France) on air kerma K{sub a}. The calibration curves are built for the TLD response R{sub TLD} vs D{sub w}, they are fitted by means of a least squares fit technique with a second degree polynomial that corrects the supra linearity response. The curves are validated by the lack of fit test, and the Anderson Darling normality test. Later on, the sensibility factors are interpolated for the sources of {sup 192} Ir: Micro Selectron and Vari Source. Two capsules are sent to two hospitals to verify a nominal D{sub w} = 2 Gy, in the first one an underestimate of the D{sub w} is obtained, and in other one an overestimation is presented. Finally, the expanded uncertainty associated to D{sub w} and the F{sub s} are calculated. (Author)

  18. Elaboration of pellets of LiF: Mg, Cu, P and its dosimetric properties; Elaboracion de pastillas de LiF: Mg, Cu, P y sus propiedades dosimetricas

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez C, A.; Gonzalez M, P.R.; Azorin N, J

    1991-03-15

    The LiF: Mg, Cu, P is at the moment in the entire world one of the TL materials of more interest, by its equivalence with the tissue, as well as for its high sensitivity, which is 25 to 35 times greater than of the TLD-100 of Harshaw (USA). In our laboratory dosemeters of this material have been developed in form of sinterized pellets. The importance of these new dosemeters in pellet form is due to that in this form its manipulation is facilitated. Due to its high sensitivity, these dosemeters result to be those but appropriate to measure the ionizing radiations, in intervals of extremely low dose. In this report the method of elaboration of the pellets, as well as its main dosimetric characteristics are presented. (Author)

  19. Dosimetric characterization of a Tl new material of LiF: Mg, Cu, P; Caracterizacion dosimetrica de un nuevo material TL de LiF: Mg, Cu, P

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R.; Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Quiroz, C. [UAEM, Facultad de Medicina, 50180, Toluca, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the method of preparation of a new material T L is described of LiF: Mg, Cu, P and the preliminary results of the tests corresponding to their dosimetric characterization are reported. The carried out tests were: detection threshold, sensitivity, dissipation of the sign T L, answer T L in function of the dose of radiation gamma, among others. The results showed that this material when receiving the one thermal treatment of having erased of 280 C by 10 min, followed by 100 C for two hours, he/she has a detection threshold ten times but I lower that that of the TLD-100, is 21 times but sensitive that that of reference and the dissipation of the sign T L during two months was null. This new material T L overcomes in many aspects to the commercial dosemeters of its type. (Author)

  20. Thermoluminescence Responses of Photon and Electron Irradiated Ge- and Al-Doped SiO2 Optical Fibres

    Institute of Scientific and Technical Information of China (English)

    H. Wagiran; I. Hossain; D. Bradley; A. N. H. Yaakob; T. Ramli

    2012-01-01

    We carry out a comparison of the thermoluminescence (TL) response of photon and electron irradiated Ge- and Al-doped SiO2 optical fibres,as well as cross-comparison with that of TLD-100.Irradiation is made with 6 MeV electrons and 6 MV photons,for doses ranging from 0.2 Gy to 4.0Gy.The commercially available Al- and Gedoped optical fibres produce a linear dose-TL response.The TL yield for both of the doped fibres and also for TLD-100 is greater for electron irradiation than for photon irradiation.The TL yield of the Al-doped fibres is a small fraction of that of Ge-doped fibres (by a factor of 25),the Ge-doped fibres offering a response of 59%o of that of TLD-100.%We carry out a comparison of the thermoluminescence (TL) response of photon and electron irradiated Ge- and Al-doped SiO2 optical fibres, as well as cross-comparison with that of TLD-100. Irradiation is made with 6 MeV electrons and 6MV photons, for doses ranging from 0.2 Gy to 4.0Gy. The commercially available Al- and Ge-doped optical fibres produce a linear dose-TL response. The TL yield for both of the doped fibres and also for TLD-100 is greater for electron irradiation than for photon irradiation. The TL yield of the Al-doped fibres is a small fraction of that of Ge-doped fibres (by a factor of 25), the Ge-doped fibres offering a response of 59% of that of TLD-100.

  1. Mensuration of equivalent dose with personal dosemeters and instruments of radiological protection in the new operative magnitudes ICRU, for external fields of beta radiation. Part I. Study of the homogeneity of the response personal dosemeters leaves (cards G-1, TLD-100), in radiation fields of Co{sub 60}; Medicion de dosis equivalente con dosimetros personales e instrumentos de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion beta externos. Parte I. Estudio de la homogeneidad de la respuesta dosimetros personales (tarjetas G-1, TLD-100), en campos de radiacion de Co{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-01-15

    A sample of 40 composed personal dosemeters by cards model: G-l, (each card is made up of two TLD-100 crystals encapsulated in teflon), Harshaw trademark; those personal dosemeters present a free window and another with a filter of A1 of 171.7 mg cm{sup -2} of mass thickness.The objective of the work is to select of this sample of 40 personal dosemeters a population with the same stocking and standard deviation. The technique used is that of comparison of stockings, (ANOVA; Variance Analysis, when samples of the same one were had size; and/or GLM, Widespread Lineal Models, when the samples were of different size), by means of the use of those Duncan statistics, SNK, Tukey, Gabriel; the results are validated proving the kindness of adjustment of the experimental data to a Normal distribution by means of the Shapiro-Wilks statistics.The experimental design used consists on a test of two vias: a via is the variable card with two levels, (crystal 1 and 2), the other via is the variable irradiation position with four levels, (LS=left superior, SR= right superior, LI= left Inferior, IR = right inferior). The irradiations carried out in blocks of four personal dosemeters in a gamma radiation beam range of Cobalt 60; carrying out three repetitions of the design. With object of proving the homogeneity of the filter of A1 in those personal dosemeters the experimental design was executed for those cards without personal dosemeters.They were also carried out tests of stockings to the readings of bottom and sensibility of the reader equipment, (Harshaw, model marks 2271), certain that doesn{sup t} exist differences for sequence of reading, but if in the stockings of the sensibility, (they were 4 different populations). The responses of the dosemeters were corrected subtracting him the reading correspondence of bottom and by sensibility of the reader equipment before subjecting them to the tests of stockings mentioned. Of the results of the tests of stockings for the cards with

  2. Radiation-Induced Color Centers in LiF for Dosimetry at High Absorbed Dose Rates

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Miller, Arne; Ellis, S. C.

    1980-01-01

    Color centers formed by irradiation of optically clear crystals of pure LiF may be analyzed spectrophotometrically for dosimetry in the absorbed dose range from 102 to 107 Gy. Routine monitoring of intense electron beams is an important application. Both 6LiF and 7LiF forms are commercially avail...... available, and when used with filters as albedo dosimeters in pairs, they provide discrimination of neutron and gamma-ray doses....

  3. Influence of polarization on irradiating LiF crystal by femtosecond laser%偏振对飞秒激光辐照LiF晶体的影响∗

    Institute of Scientific and Technical Information of China (English)

    王承伟; 赵全忠; 张扬; 王关德; 钱静; 鲍宗杰; 李阳博; 柏锋; 范文中

    2015-01-01

    The processing morphology of cubic crystal LiF irradiated by femtosecond laser varies with the polarization direc-tion. When the polarization direction is parallel to the crystal orientation⟨110⟩, the distance between the starting point and the surface is 1.08 times that along ⟨100⟩ polarization, and the distance between the end point and the surface is 1.01 times. While the cubic crystal is irradiated by a femtosecond laser, self-focusing and inverse bremsstrahlung are two probable mechanisms dependent on polarization. In order to investigate the relation between the self-focusing and polarization, in this paper we report the nonlinear refractive index n2 of LiF crystal which is linear with respect to self-focusing coefficient. The Z-scan technique is used to measure the nonlinear refractive indexes at different polarizations. As the polarization direction is rotated from⟨110⟩to⟨100⟩, the nonlinear refractive index decreases, and the self-focusing effect becomes weaker. If self-focusing leads to the dependence of morphology on polarization, the distance between the starting point and the surface for ⟨100⟩ polarization should be longer than that for ⟨110⟩ polarization. However, the experiment exhibits an opposite result that the distance between starting point and the surface for⟨100⟩polarization is shorter than that for⟨110⟩polarization. Therefore, the processing morphology which changes with polarization is not a consequence of the self-focusing. So in order to understand why the processing morphology varies with polarization, in this paper we present a model which combines inverse bremsstrahlung, avalanche ionization and radiationless transition. We believe that the recombination due to radiationless transition has a great effect on laser machining. The inverse bremsstrahlung coefficient of ⟨110⟩ polarization is less than that of ⟨100⟩ polarization, as a result, the density of free electrons which are produced by inverse

  4. Synthesis and characterization of europium doped LiF phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Villalobos, M. L.; Vallejo, M. A.; Sosa A, M. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Loma del Bosque No. 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Diaz T, L. A., E-mail: villaloboscm2010@licifug.ugto.mx [Centro de Investigaciones en Optica, A. C., Loma del Bosque No. 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2015-10-15

    LiF with different dopants has been one of the most investigated materials to use as thermoluminescent dosimeter. In this paper, we present the preparation method, the characterization and the thermoluminescent response of Eu doped LiF irradiated with X-rays. Pure and Eu doped LiF samples with different dopant concentration (0, 0.25, 0.5, 0.75 and 1 % mol) were synthesized using the precipitation method. The samples were structurally characterized by X-ray diffraction (XRD), the diffraction patterns showed a main cubic crystalline structure and a secondary hexagonal structure. The photoluminescence spectrum exhibited four well defined peaks characteristic of the Eu{sup 3+} ion. Thermoluminescent (Tl) glow curves of x-ray irradiated samples showed a well-defined single peak around 200 degrees C, except for the pure and 0.25% Eu doped samples. (Author)

  5. Fabrication of Microstructures in LiF Crystals by a Femtosecond Laser

    Institute of Scientific and Technical Information of China (English)

    赵全忠; 邱建荣; 杨旅云; 姜雄伟; 赵崇军; 朱从善

    2003-01-01

    We report the space-selective formation of colour centres and refractive index change in LiF crystals at room temperature by an 800nm Ti:sapphire femtosecond laser irradiation. Optical absorption and photoluminescence spectra have been measured for the crystal before and after the laser irradiation. The absorption spectra indicate F and F+3 colour centres are induced in LiF after the laser irradiation. When the temperature of heat treatment reaches 300 ℃, the absorption peak disappears, indicating that the induced colour centres are bleached. The induced refractive index change is also evaluated. A mechanism for the formation of colour centres and refractive index change is proposed.

  6. LIF signaling in stem cells and development.

    Science.gov (United States)

    Onishi, Kento; Zandstra, Peter W

    2015-07-01

    Leukemia inhibitory factor (LIF) is a member of the interleukin-6 (IL-6) cytokine family. All members of this family activate signal transducer and activator of transcription 3 (STAT3), a transcription factor that influences stem and progenitor cell identity, proliferation and cytoprotection. The role of LIF in development was first identified when LIF was demonstrated to support the propagation of mouse embryonic stem cells. Subsequent studies of mice deficient for components of the LIF pathway have revealed important roles for LIF signaling during development and homeostasis. Here and in the accompanying poster, we provide a broad overview of JAK-STAT signaling during development, with a specific focus on LIF-mediated JAK-STAT3 activation.

  7. Radiological environmental monitoring with LiF-700-H dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Scarnichia, E.; Levanon, I.; Andres, P.; Miani, C.; Ramirez, S., E-mail: andresp@cab.cnea.gov.ar [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Grupo Proteccion Radiologica, Exequiel Bustillo 5AV 9500, R8402AGP San Carlos de Bariloche, Rio Negro (Argentina)

    2011-10-15

    Since 2008 a radiological environmental monitoring with LiF-700-H has been carried out as a result of increasing the Ra-6 research reactor core power. The information obtained is used to evaluate and to quantify analytically the air kerma rate, the fading and the associated uncertainty by developing software tools (deconvolution and uncertainty algorithms). LiF-700-H dosemeters were chosen because of their high sensitivity to low air kerma rates. They show a very good stability and a negligible fading for two-month working periods. The air kerma rate detection limit (based on the 3{sigma} criterion) during these working periods is about 0.4 n Gy/h. Air kerma rates of about 70 n Gy/h are measured with this detection limit. Following the Nist guidelines, an algorithm was developed in order to find the associated uncertainty. It considers several aspects, such as the source activity decay, distance source-dosemeter during the calibration procedure, irradiation time, calibration factor, dosemeter readout, dosemeter sensitivity, TLD reader stability and fading. The associated uncertainty is found to be about 25% for a 95% confidence interval (k = 2.025), which can be considered acceptable when taking into account the very low air kerma rates estimated. The LiF-700-H response to different energies and its relationship with climate changes over the calendar year are planned as future tasks. (Author)

  8. Thermoluminescence characteristics of LiF: Cu nanocrystalline phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Seth, Pooja, E-mail: pujaseth05@gmail.com; Aggarwal, Shruti [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi (India)

    2016-05-23

    Copper (Cu) activated LiF phosphor in nanocrystalline form has been prepared by the chemical co-precipitation method for radiation dosimetry application. The formation of nanocrystalline structure has been confirmed by X-ray diffraction and Scanning electron microscopy. Cubical shaped nanostructure with average particle size of 33nm has been formed. The sample was prepared at different concentration of Cu from 0.01mol% to 3 mol%. TL properties were investigated by studying the glow curve after irradiating the phosphor to gamma ray Co{sup 60} source with dose of 15 Gy. It has been found that nanocrystalline LiF: Cu show simple glow curve structure with a single glow peak at 404 K where as commercially available phosphors exhibits multi peak complex glow curve structure. The effect of different normality on the TL properties of phosphor has been studied. Maximum TL intensity for LiF: Cu (0.1mol %) phosphor is observed at the normality of 0.5N and annealing temperature of 200°C. The phosphor showed good linearity up to 10 KGy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  10. Effect of spectral shape in the relative efficiency of LiF: Mg,Ti exposed to 20 keV effective energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Ixquiac-Cabrera, J.M., E-mail: mixquiac@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 DF (Mexico); Departamento de Fisica, Universidad de San Carlos de Guatemala, Edificio T-1 Facultad de Ingenieria (Guatemala); Brandan, M.E.; Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Ruiz-Trejo, C. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 DF (Mexico); Gamboa-deBuen, I. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 DF (Mexico)

    2011-04-15

    This work is aimed at studying the possible dependence of the thermoluminescent response of LiF:Mg,Ti (TLD-100) on the X-ray beam spectrum. TLD-100 chips were irradiated with 20 keV effective energy filtered tungsten X-ray spectra, generated by a tube operated at 30, 40, 50, 60, 70 and 80 kV, and the response was measured relative to the response to {sup 60}Co gammas. TLDs were exposed in air at air kerma values between 50 and 300 mGy. Glow curve deconvolution into 8 peaks (3, 4, 5, 6a, 6b, 7, 8 and 9) was performed in order to evaluate the response of individual peaks and regions of interest in the glow curve. Results show that all peaks display a linear response, at least up to 200 mGy, for all X-ray beam qualities. The relative response of the total glow curve area, the dosimetric region (peaks 3 + 4 + 5) and peaks 5 to 9 is statistically constant for beams generated by voltages from 30 to 70 kV; for 80 kV, the values are lower by about 20% for peaks 8 and 9 and 9% for the rest. The relative efficiency for the glow curve area, the dosimetric region and peaks 5 (1.15, 1.10 and 1.13), peaks 8 and 9 (2.05 and 1.55) do not depend on the beam spectrum between 30 and 70 kV, while for 80 kV the efficiency is lower. For peaks 6a, 6b and 7, relative efficiencies (1.91, 2.94 and 2.60) are voltage independent.

  11. 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)

  12. Synthesis and characterization of LiF: Mg, Ti for ionizing radiations dosimetry; Sintesis y caracterizacion de LiF: Mg, Ti para dosimetria de radiaciones ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Lozano R, I. B.

    2011-07-01

    Among the different thermoluminescence materials (Tl), the LiF:Mg, Ti is the most used for dosimetric purposes, because its equivalence to the human tissue, it has an effective atomic number of 8.14, the best known commercial dosemeter of this kind is the TLD-100. However, because this dosimeter is an imported product, is quite expensive for many research groups and hospitals. The purpose of this work is the optimization of its synthesis, as the dosimetric characterization, so it can replace the imported dosimeters. The synthesis of LiF:Mg, Ti is a careful process, since one of the reagents, the ion fluorine is highly corrosive. In this work the synthesis of the LiF:Mg, Ti was done by the molten substance method, was used LiF of analytical grade and the magnesium (Mg) and titanium (Ti) activators were incorporated in aqueous solution. For to optimize the handle of the material Tl, we elaborated pellets and teflon (Ptfe) was used as agglutinate material, in a 2:3 proportion. First was prepared the LiF, incorporating just Mg as dopant with a concentration of 400 parts per million (ppm). After the Ti with concentrations from 15 to 120 ppm was incorporated keeping fixed the concentration of Mg (400 ppm). The morphological and structural characterization of the Tl material were made by scanning electron microscopy and X-ray diffraction. The optimal concentration of Ti, was determined as a function of the radiation dose sensibility of the Tl material. The material prepared with 60 ppm of the Ti showed a higher sensibility. However, also the rest of the preparations had the requirements recommended by the international agencies to be used in ionizing radiations dosimetry. For the dosimetric characterization were used samples with 400 ppm of Mg, 400 ppm Mg and 30 ppm Ti, 400 ppm Mg and 60 ppm Ti. The LiF:Mg showed its dosimetric peak at 240 C, while the LiF:Mg, Ti (30 ppm and 60 ppm Ti) showed their dosimetric peak at 220 C and 222 C respectively. The study of the Tl

  13. Thermally and optically stimulated luminescence of AlN-Y2O3 ceramics after ionising irradiation

    DEFF Research Database (Denmark)

    Trinkler, L.; Bos, A.J.J.; Winkelman, A.J.M.;

    1999-01-01

    Thermally (TL) and optically stimulated luminescence (OSL) were studied in AlN-Y2O3 ceramics after irradiation with ionising radiation. The extremely high TL sensitivity (approximately 60 times the sensitivity of LiF:Mg,Tl (TLD-100)) makes AlN-Y2O3 ceramics attractive as a TLD material. However......, an essential drawback of AlN-Y2O3 is its high fading rate. Special attention has been focused on understanding and improving the fading properties. In particular, the influence of the ceramics production conditions and the additive concentration on the fading rate have been studied. Experimental results...

  14. 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)

  15. Optimization of a sup 6 LiF bolometric neutron detector

    CERN Document Server

    Silver, C S; Piccirillo, L; Timbie, P T; Zhou, J W

    2002-01-01

    The optimization of a sup 6 LiF bolometer for neutron spectroscopy applications has been accomplished with a series of 12 different detectors. This type of detector is similar to X-ray bolometers, which have been extensively studied, and the absorber has a high neutron capture cross-section. Each bolometer was irradiated with alpha particles to investigate its response to thermal pulses. The best resolution obtained with this series of bolometers was 39 keV FWHM at 5.3 MeV. One of the bolometers was calibrated with monoenergetic neutrons, and its thermal properties are derived from measurements over a range of temperatures. We discuss the considerations involved in optimizing a sup 6 LiF bolometer for different types of neutron applications.

  16. Point defects induced in LiF by low energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Baldacchini, Giuseppe; Montereali, Rosa Maria [ENEA, Centro Ricerche Frascati, Rome (Italy); Scacco, Augusto [Rome, Univ. (Italy). Dipt. di Fisica]|[INFM, Rome (Italy); Cremona, Marco; D`Auria, Giuliano

    1997-09-01

    A systematic study of the coloring of LiF crystals and films irradiated by 3 keV electrons at various temperatures was carried out analysing their absorption and luminescence spectra. The three stage behaviour of the F coloring curve as a function of the irradiation dose was revealed and the saturation of the process was identified for the first time with this kind of radiation. The kinetics of the defect formation confirmed the expectations derived from the most comprehensive theoretical model developed to explain the coloring process. The irradiation temperature was found to have an influence on both the proportion of different defects created and on their stability and the overall coloring efficiency turned out to be higher when the irradiation was performed on films. Various explanations to these observations are put forward and discussed.

  17. Thermal annealing study of F center clusters in LiF single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Izerrouken, M., E-mail: izerrouken@yahoo.co [Centre de Recherche Nucleaire de Draria (CRND), BP 43, Sebbala, Draria, Alger (Algeria); Guerbous, L. [Centre de Recherche Nucleaire d' Alger (CRNA), 2 Bd Frantz Fanon, BP 399, Alger gare (Algeria); Meftah, A. [LRPCSI, Universite 20 Aout 55 route d' El-Hadaik, BP 26, 21000 Skikda (Algeria)

    2010-01-21

    The present work is devoted to study the thermal annealing process of F center clusters (F{sub n}) induced in LiF single crystal under high-dose gamma-rays and high reactor neutrons fluence irradiations. With heating under argon atmosphere, the F-type center aggregates and gives rise to a new absorption band at 500 nm attributed to Li colloids. The optical density associated with F{sub 2} center observed in gamma-ray irradiated LiF decreases with increasing annealing temperature and exhibits two distinct annealing processes with activation energies E{sub 1}=0.9+-0.3 eV and E{sub 2}=1.6+-0.5 eV. Also, it is clear from the results that the F{sub 3}{sup +} and F{sub 2} emission bands positions are affected by the irradiated dose. Reactor neutrons irradiation induces large Li colloids. These colloids persist even after annealing at 450 deg. C.

  18. In vivo clinical dosimetry with LiF: PTFE dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, A. (Junta de Energia Nuclear, Madrid (Spain)); Manzanas, M.J.; Fernandez Leton, P. (Clinica Seg. Soc. 1. Octubre, Madrid (Spain))

    1984-01-01

    The purpose of this report is to describe the implementation of a dosimetric system suitable for ''in vivo'' measurements in some clinical applications. This system is based in re-usable thermoluminiscent dosimeters of Lithium fluoride embebded in teflon (PTFE). The results obtained in the utilization of these dosimeters for the determination of entrance absorbed doses on an antropomorphical phantom and patients are also presented. The irradiations have been made in several anatomical localizations with /sup 60/Co gamma rays. A great number of measurements has been made to determine properly the precision that can be reached with LiF: PTFE dosimeters. A considerable improvement of this precission has been obtained calibrating individually each dosimeter. The effects of the remanent sensibilization of the dosimeters that have received relatively high doses (approx. 1 Gy) are also reported. In order to take into account this unwanted effect it is necessary to calibrate frequently the dosimeters during their useful life, lowering, in this way, the risk of making wrong assignation of absorbed doses. From the results obtained in the measurements of absorbed doses in patients, it is clearly deduced that, even in anatomical localizations without special difficulties, such as the abdominal: flat and without problems to maintain the treatment position, rather high discrepancies can be found between the planned doses and those really imparted in practice. These results confirms the usefulness of making patient dose measurements in order to have effective control of the necessary quality of the therapeutical treatments.

  19. 6LiF oleic acid capped nanoparticles entrapment in siloxanes for thermal neutron detection

    Science.gov (United States)

    Carturan, S.; Maggioni, G.; Marchi, T.; Gramegna, F.; Cinausero, M.; Quaranta, A.; Palma, M. Dalla

    2016-07-01

    The good light output of siloxane based scintillators as displayed under γ-rays and α particles has been exploited here to obtain clear and reliable response toward thermal neutrons. Sensitization towards thermal neutrons has been pursued by adding 6LiF, in form of nanoparticles. Aiming at the enhancement of compatibility between the inorganic nanoparticles and the low polarity, siloxane based surrounding medium, oleic acid-capped 6LiF nanoparticles have been synthesized by thermal decomposition of Li trifluoroacetate. Thin pellets siloxane scintillator maintained their optical transmittance up to weight load of 2% of 6Li. Thin samples with increasing 6Li concentration and thicker ones with fixed 6Li amount have been prepared and tested with several sources (α, γ-rays, moderated neutrons). Light output as high as 80% of EJ212 under α irradiation was measured with thin samples, and negligible changes have been observed as a result of 6LiF addition. In case of thick samples, severe light loss has been observed, as induced by opacity. Nevertheless, thermal neutrons detection has been assessed and the data have been compared with GS20, based on Li glass, taken as a reference material.

  20. Production of waveguides in LiF by MeV ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, J.A.M. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil)]. E-mail: jamp@fge.if.usp.br; Cremona, M. [PUC-Rio, Physics Department, CP 38071, 22452-970 Rio de Janeiro, RJ (Brazil); Pelli, S. [Nello Carrara Institute of Applied Physics - CNR, Optoelectronics and Photonics Department, via Panciatichi 64, 50127 Firenze (Italy); Macchione, E.L.A. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Koide, K. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Vasconcelos, S.S. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Righini, G.C. [Nello Carrara Institute of Applied Physics - CNR, Optoelectronics and Photonics Department, via Panciatichi 64, 50127 Florence (Italy)

    2005-10-15

    Alkali fluorides containing color centers are promising systems for applications in new integrated optical devices like active waveguides and color center lasers. In this work, we report the development of a simple method, based on high-energy ion beam irradiation, to create active waveguides in alkali halide materials. MeV carbon and helium beams at normal incidence were used to irradiate lithium fluoride crystals, with different ion doses varying from 10{sup 14} up to 10{sup 16} cm{sup -2}, producing thin colored strips. Irradiated waveguides were also characterized by means of optical absorption spectroscopy in order to obtain the distribution of the color centers induced by the ion beam. The results confirm the feasibility of integrated active devices based on color centers in LiF such as tunable light amplifiers, lasers and hybrid optoelectronic components.

  1. Confocal fluorescence microscopy investigation of visible emitting defects induced by electron beam lithography in LIF films

    Energy Technology Data Exchange (ETDEWEB)

    Montereali, R.M.; Bigotta, S.; Pace, A.; Piccinini, M. [ENEA, Divisione Fisica Applicata, Centro Ricerche Frascati, Frascati, RM (Italy); Burattini, E.; Grilli, A.; Raco, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Fisica, Frascati, Rome (Italy); Giammatteo, M. [Unita' Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy)]|[L' Aquila Univ., L' Aquila (Italy). Centro di Microscopia Elettronica; Picozzi, P.; Santucci, S. [Unita' Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy)]|[L' Aquila Univ., L' Aquila (Italy). Dipt. di Fisica

    2000-07-01

    Low energy electron irradiation of lithium fluoride (LiF), in the form of bulk crystals and films, gives rise to the stable formation of primary F defects and aggregated color centers in a thin layer located at the surface of the investigated material. For the first time a confocal light scanning microscope (CLSM) in fluorescence mode was used to reconstruct the depth distribution of efficiently emitting laser active color centers in a stripe-like region induced by 12 and 16 keV electrons on LiF films thermally evaporated on glass. The formation of the F{sub 3}{sup +} and F{sub 2} aggregated defects appears restricted to the electron penetration and proportional to their energy depth profile, as obtained from Monte Carlo simulations. [Italian] L'irraggiamento con elettroni di bassa energia del fluoruro di litio (LiF), in forma di cristalli e film, induce la formazione di difetti primari F e centri di colore aggregati stabili in un sottile strato localizzato alla superficie del materiale investigato. Per la prima volta un microscopio confocale a scansione (CLSM) in modalita' fluorescenza e' stato usato per ricostruire la distribuzione di centri di colore laser attivi ad alta efficienza di emissione nel visibile, in strisce colorate ottenute con elettroni da 12 e 16 keV su film di LiF evaporati termicamente su vetro. La formazione dei difetti aggregati F2 e F3+ risulta ristretta spazialmente nella regione di penetrazione degli elettroni e proporzionale al profilo della distribuzione dell'energia da essi depositata, ricavata tramite simulazioni Monte Carlo.

  2. Electrical conduction of LiF interlayers in organic diodes

    Energy Technology Data Exchange (ETDEWEB)

    Bory, Benjamin F.; Janssen, René A. J.; Meskers, Stefan C. J., E-mail: s.c.j.meskers@tue.nl [Molecular Materials and Nanosystems and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Gomes, Henrique L. [Instituto de Telecomunicações, Av. Rovisco, Pais, 1, 1049–001, Lisboa, Portugal and Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Leeuw, Dago M. de [Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany and King Abdulaziz University, Jeddah (Saudi Arabia)

    2015-04-21

    An interlayer of LiF in between a metal and an organic semiconductor is commonly used to improve the electron injection. Here, we investigate the effect of moderate bias voltages on the electrical properties of Al/LiF/poly(spirofluorene)/Ba/Al diodes by systematically varying the thickness of the LiF layer (2-50 nm). Application of forward bias V below the bandgap of LiF (V < E{sub g} ∼ 14 V) results in reversible formation of an electrical double layer at the LiF/poly(spirofluorene) hetero-junction. Electrons are trapped on the poly(spirofluorene) side of the junction, while positively charged defects accumulate in the LiF with number densities as high as 10{sup 25}/m{sup 3}. Optoelectronic measurements confirm the built-up of aggregated, ionized F centres in the LiF as the positive trapped charges. The charged defects result in efficient transport of electrons from the polymer across the LiF, with current densities that are practically independent of the thickness of the LiF layer.

  3. LIF-free embryonic stem cell culture in simulated microgravity.

    Directory of Open Access Journals (Sweden)

    Yumi Kawahara

    Full Text Available BACKGROUND: Leukemia inhibitory factor (LIF is an indispensable factor for maintaining mouse embryonic stem (ES cell pluripotency. A feeder layer and serum are also needed to maintain an undifferentiated state, however, such animal derived materials need to be eliminated for clinical applications. Therefore, a more reliable ES cell culture technique is required. METHODOLOGY/PRINCIPAL FINDINGS: We cultured mouse ES cells in simulated microgravity using a 3D-clinostat. We used feeder-free and serum-free media without LIF. CONCLUSIONS/SIGNIFICANCE: Here we show that simulated microgravity allows novel LIF-free and animal derived material-free culture methods for mouse ES cells.

  4. LIF-imaging and gas-phase diagnostics of laser desorbed MALDI-matrix plumes

    Energy Technology Data Exchange (ETDEWEB)

    Puretzky, A.A.; Geohegan, D.B. [Oak Ridge National Lab., TN (United States). Solid State Div.

    1997-07-01

    The first gated LIF-imaging and absorption spectroscopy has been performed on laser desorbed plumes from organic crystals which are commonly used as MALDI (Matrix Assisted Laser Desorption Ionization) matrices. These plasma diagnostic techniques, including ion probe measurements were employed to investigate the desorbed products, densities, fractional ionization, and velocity distributions of the plume of ejecta which is typically employed as the main desorption product in the mass spectrometry analysis of large biomolecules. Ultraviolet pulsed 193-nm and 248-nm irradiation of 3-hydroxypicolinic acid (3-HPA) crystals were studied to understand the effect of very different gas-phase absorption cross sections measured here for this material. In both cases, LIF imaging revealed two plume components: a fast (maximum {approximately} 0.1 cm/{micro}s) low-intensity component which appear to be 3-HPA fragments, and a slower component of 3-HPA expanding at 0.05 cm/{micro}s. In the case of ArF-laser irradiation, optical absorption spectroscopy indicated a breaking of the intramolecular hydrogen bond in the gas-phase matrix material.

  5. Characterization of X-ray polycapillary optics by LiF crystal radiation detectors through confocal fluorescence microscopy

    Science.gov (United States)

    Bonfigli, Francesca; Hampai, Dariush; Dabagov, Sultan B.; Montereali, Rosa Maria

    2016-08-01

    Solid-state radiation imaging detectors based on photoluminescent colour centres in lithium fluoride (LiF) crystals have been successfully tested for both advanced 2D and 3D characterizations of X-ray polycapillary optics by a table-top laboratory system. Polycapillary optics can control X-ray beams propagation and allows obtaining quasi-parallel beam (half-lens) or focused beams (full-lens). The combination of a fine-focused micro X-ray tube and a polycapillary lens can provide the high intensity radiation fluxes that are necessary for high resolution X-ray imaging. In this paper we present novel results about advanced characterization of these complex optics by 2D as well as 3D confocal laser fluorescence microscopy of X-ray irradiated LiF crystal detectors. Two dimensional high spatial resolution images on a wide field of view of transmitted X-rays through a semi-lens and 3D direct inspection of the coloured volumes produced in LiF crystals by both focused and parallel X-ray beam transmitted by a full and a semi-lens, respectively, as well as their 3D reconstructions were obtained. The results show that the photoluminescent colour centres volume in LiF crystals combined with an optical sectioning reading system provide information about tomography of transmitted X-ray beams by policapillary optics in a single exposure process. For the first time, the use of LiF crystal plates as versatile radiation imaging luminescent detectors have been used to characterize the operation of polycapillary optics as X-ray lens, in focusing and parallel mode.

  6. Research of mine water source identification based on LIF technology

    Science.gov (United States)

    Zhou, Mengran; Yan, Pengcheng

    2016-09-01

    According to the problem that traditional chemical methods to the mine water source identification takes a long time, put forward a method for rapid source identification system of mine water inrush based on the technology of laser induced fluorescence (LIF). Emphatically analyzes the basic principle of LIF technology. The hardware composition of LIF system are analyzed and the related modules were selected. Through the fluorescence experiment with the water samples of coal mine in the LIF system, fluorescence spectra of water samples are got. Traditional water source identification mainly according to the ion concentration representative of the water, but it is hard to analysis the ion concentration of the water from the fluorescence spectra. This paper proposes a simple and practical method of rapid identification of water by fluorescence spectrum, which measure the space distance between unknown water samples and standard samples, and then based on the clustering analysis, the category of the unknown water sample can be get. Water source identification for unknown samples verified the reliability of the LIF system, and solve the problem that the current coal mine can't have a better real-time and online monitoring on water inrush, which is of great significance for coal mine safety in production.

  7. LIF Mediates Proinvasive Activation of Stromal Fibroblasts in Cancer

    Directory of Open Access Journals (Sweden)

    Jean Albrengues

    2014-06-01

    Full Text Available Signaling crosstalk between tumor cells and fibroblasts confers proinvasive properties to the tumor microenvironment. Here, we identify leukemia inhibitory factor (LIF as a tumor promoter that mediates proinvasive activation of stromal fibroblasts independent of alpha-smooth muscle actin (α-SMA expression. We demonstrate that a pulse of transforming growth factor β (TGF-β establishes stable proinvasive fibroblast activation by inducing LIF production in both fibroblasts and tumor cells. In fibroblasts, LIF mediates TGF-β-dependent actomyosin contractility and extracellular matrix remodeling, which results in collective carcinoma cell invasion in vitro and in vivo. Accordingly, carcinomas from multiple origins and melanomas display strong LIF upregulation, which correlates with dense collagen fiber organization, cancer cell collective invasion, and poor clinical outcome. Blockade of JAK activity by Ruxolitinib (JAK inhibitor counteracts fibroblast-dependent carcinoma cell invasion in vitro and in vivo. These findings establish LIF as a proinvasive fibroblast producer independent of α-SMA and may open novel therapeutic perspectives for patients with aggressive primary tumors.

  8. LIF-dependent signaling: new pieces in the Lego.

    Science.gov (United States)

    Mathieu, Marie-Emmanuelle; Saucourt, Claire; Mournetas, Virginie; Gauthereau, Xavier; Thézé, Nadine; Praloran, Vincent; Thiébaud, Pierre; Bœuf, Hélène

    2012-03-01

    LIF, a member of the IL6 family of cytokine, displays pleiotropic effects on various cell types and organs. Its critical role in stem cell models (e.g.: murine ES, human mesenchymal cells) and its essential non redundant function during the implantation process of embryos, in eutherian mammals, put this cytokine at the core of many studies aiming to understand its mechanisms of action, which could benefit to medical applications. In addition, its conservation upon evolution raised the challenging question concerning the function of LIF in species in which there is no implantation. We present the recent knowledge about the established and potential functions of LIF in different stem cell models, (embryonic, hematopoietic, mesenchymal, muscle, neural stem cells and iPSC). We will also discuss EVO-DEVO aspects of this multifaceted cytokine.

  9. Relevance of LIF and EGF on Mouse Preimplantation Embryo Development

    Directory of Open Access Journals (Sweden)

    Iraj Amiri

    2008-01-01

    Full Text Available Objective: Recent evidence suggests that Leukemia Inhibitory Factor (LIF, a member ofinterleukin-6 family, has biological actions on preimplantation embryo development. Alsoit is established that Epidermal Growth Factor (EGF, a strong mitosis-promoting agent,improves the preimplantation embryo development by increasing the cell metabolism andproliferation. The purpose of the present study is to investigate the effects of these factors,alone and in combination together, on preimplantation and development of the embryo.Materials and Methods: Six to eight weeks old NMRI mice were super ovulated by injectionof 10IU PMSG and 10IU hCG, then the mated mice were killed 46 hours later. Theiroviducts were flushed, two-cell embryos collected and divided randomly to the four groupsas following: Control, treatment 1 (LIF, treatment 2 (EGF, treatment 3 (LIF+EGF. In eachgroup, the embryos were cultured in an incubator at 37°C with 5% CO2 and 90% humidityfor 72hrs. The state of embryo development was evaluated in 24,36,48,60 and 72hrsfollowing the embryos cultures. By the end of the cultures, cell apoptosis was studiedby the terminal deoxynucleotidyl transferas-mediated dUTP nick end-labeling (TUNELtechnique.Results: Significant difference was detected in the rate of hatching in the LIF and LIF+EGFgroups. This difference was also seen in the rate of blastocyst formation after 36hrs(p<0.05 and in the average of the total cell number (p<0.05 after 72hrs. In comparison tothe apoptotic index, there was no significant difference between the control and treatmentgroups.Conclusion: The findings in this study show a beneficial effect of LIF and EGF on theblastocyst formation, hatching and its total cell numbers in vitro.

  10. Analysis of the stability of the traps in LiF: Mg, Cu, P by deconvolution of it Tl curve; Analisis de la estabilidad de las trampas en LiF: Mg, Cu, P por deconvolucion de su curva TL

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [UAM-I, San Rafael Atlixco 186, Col Vicentina 09340 Mexico, D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185, Roma, (Italy); Lopez, J. [Facultad de Matematicas, UADY, s/C.P. Merida, Yucatan (Mexico)

    2004-07-01

    The results of the study of the stability of the traps are presented in Tl dosemeters of LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese factory. The readings taken Tl the same day of the irradiation they presented four peaks whose energy, determined by deconvolution were; 1.30 {+-} 0.01 eV, 1.50 {+-} 0.01 eV, 1.70 {+-} 0.01 eV and 2.58{+-} 0.02 eV, for LiF: Mg,Cu,P + Ptfe, while for GR200A the energies were: 1.33 {+-} 0.11 eV, 1.58 {+-} 0.11 eV, 1.73 {+-} 0.11 eV and 2.60 {+-} 0.03 eV. The energy of the peaks 3 and 4 that remained visible during six months of study it was: 1.38 {+-} 0.01 eV and 2.65 {+-} 0.01 eV, for LiF: Mg,Cu,P + Ptfe respectively, in the same order for GR200A, the energies were: 1.51 {+-} 0.02 eV and 2.64 {+-} 0.03 eV. (Author)

  11. Low temperature dosimetry in LiF: Mg, Cu, P and CaSO{sub 4}: Dy doped crystals; Dosimetria de baja temperatura en cristales dopados LiF: Mg, Cu, P y CaSO{sub 4}: Dy

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, E.; Ramos B, S.; Negron M, A.; Rivera, T. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543, 04510 Mexico D.F. (Mexico)

    2000-07-01

    It is presented a behavior study of LiF solid dosemeters doped with Mg, Cu and P also polycrystalline samples of CaSO{sub 4} with Dy sinterized in laboratory, both of them were subjected at low temperature. In order to analyse linear behavior to the dose of these dosemeters, it was used thermoluminescence. These materials were exposed to gamma radiation coming from a Co-60 source. The samples were irradiated at dose rates 1.08 {+-} 0.01 Gy/min at liquid nitrogen temperature (LNT) and also the response of dosemeters are compared at ambient temperature and LNT. (Author)

  12. Low temperature dosimetry in LiF: Mg, Cu, P and CaSO{sub 4}: Dy doped crystals; Dosimetria de baja temperatura en cristales dopados LiF: Mg, Cu, P y CaSO{sub 4}: Dy

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, E.; Ramos B, S.; Negron M, A.; Rivera, T. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543, 04510 Mexico D.F. (Mexico)

    2000-07-01

    It is presented a behavior study of LiF solid dosemeters doped with Mg, Cu and P also polycrystalline samples of CaSO{sub 4} with Dy sinterized in laboratory, both of them were subjected at low temperature. In order to analyse linear behavior to the dose of these dosemeters, it was used thermoluminescence. These materials were exposed to gamma radiation coming from a Co-60 source. The samples were irradiated at dose rates 1.08 {+-} 0.01 Gy/min at liquid nitrogen temperature (LNT) and also the response of dosemeters are compared at ambient temperature and LNT. (Author)

  13. Boron Diffused Thermoluminescent Surface Layer in LiF TLDs for Skin Dose Assessments

    DEFF Research Database (Denmark)

    Christensen, Poul; Majborn, Benny

    1980-01-01

    A new high-temperature glow peak produced in a thin surface layer of LiF TLDs by diffusion of boron into the LiF material has been studied for skin dose assessments in personnel dosimetry.......A new high-temperature glow peak produced in a thin surface layer of LiF TLDs by diffusion of boron into the LiF material has been studied for skin dose assessments in personnel dosimetry....

  14. MagLIF scaling on Z and future machines

    Science.gov (United States)

    Slutz, Stephen; Stygar, William; Gomez, Matthew; Campbell, Edward; Peterson, Kyle; Sefkow, Adam; Sinars, Daniel; Vesey, Roger

    2015-11-01

    The MagLIF (Magnetized Liner Inertial Fusion) concept [S.A. Slutz et al Phys. Plasmas 17, 056303, 2010] has demonstrated [M.R. Gomez et al., PRL 113, 155003, 2014] fusion-relevant plasma conditions on the Z machine. We present 2D numerical simulations of the scaling of MagLIF on Z indicating that deuterium/tritium (DT) fusion yields greater than 100 kJ could be possible on Z when operated at a peak current of 25 MA. Much higher yields are predicted for MagLIF driven with larger peak currents. Two high performance pulsed-power machines (Z300 and Z800) have been designed based on Linear Transformer Driver (LTD) technology. The Z300 design would provide approximately 48 MA to a MagLIF load, while Z800 would provide about 66 MA. We used a parameterized Thevenin equivalent circuit to drive a series of 1D and 2D numerical simulations with currents between and beyond these two designs. Our simulations indicate that 5-10 MJ yields may be possible with Z300, while yields of about 1 GJ may be possible with Z800. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. LIF supports primitive endoderm expansion during pre-implantation development

    DEFF Research Database (Denmark)

    Morgani, Sophie M; Brickman, Joshua M

    2015-01-01

    report that LIF has two distinct roles: it blocks early epiblast (Epi) differentiation, and it supports the expansion of primitive endoderm (PrE)-primed ESCs and PrE in vivo. We find that activation of JAK/STAT signalling downstream of LIF occurs initially throughout the pre-implantation embryo......, but later marks the PrE. Moreover, the addition of LIF to cultured embryos increases the GATA6(+) PrE population, whereas inhibition of JAK/STAT signalling reduces both NANOG(+) epiblast and GATA6(+) PrE. The reduction of the NANOG(+) Epi might be explained by its precocious differentiation to later Epi...... derivatives, whereas the increase in PrE is mediated both by an increase in proliferation and inhibition of PrE apoptosis that is normally triggered in embryos with an excess of GATA6(+) cells. Thus, it appears that the relative size of the PrE is determined by the number of LIF-producing cells in the embryo...

  16. Hundred joules plasma focus device as a potential pulsed source for in vitro cancer cell irradiation

    Science.gov (United States)

    Jain, J.; Moreno, J.; Andaur, R.; Armisen, R.; Morales, D.; Marcelain, K.; Avaria, G.; Bora, B.; Davis, S.; Pavez, C.; Soto, L.

    2017-08-01

    Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely "PF-400J", was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.

  17. Organic Light-Emitting Devices with a LiF Hole Blocking Layer

    Institute of Scientific and Technical Information of China (English)

    LIAN Jia-Rong; YUAN Yong-Bo; ZHOU Xiang

    2007-01-01

    We introduce a thin LiF layer into tris-8-hydroxyquinoline aluminium (Alq3) based bilayer organic light-emittingdevices to block hole transport. By varying the thickness and position of this LiF layer in Alq3, we obtain an electroluminescent efficiency increase by a factor of two with respect to the control devices without a LiF blocking layer. By using a 10nm dye doped Alq3 sensor layer, we prove that LiF can block holes and excitons effectively.Experimental results suggest that the thin LiF layer may be a good hole and exciton blocking layer.

  18. Upregulation of leukemia inhibitory factor (LIF during the early stage of optic nerve regeneration in zebrafish.

    Directory of Open Access Journals (Sweden)

    Kazuhiro Ogai

    Full Text Available Fish retinal ganglion cells (RGCs can regenerate their axons after optic nerve injury, whereas mammalian RGCs normally fail to do so. Interleukin 6 (IL-6-type cytokines are involved in cell differentiation, proliferation, survival, and axon regrowth; thus, they may play a role in the regeneration of zebrafish RGCs after injury. In this study, we assessed the expression of IL-6-type cytokines and found that one of them, leukemia inhibitory factor (LIF, is upregulated in zebrafish RGCs at 3 days post-injury (dpi. We then demonstrated the activation of signal transducer and activator of transcription 3 (STAT3, a downstream target of LIF, at 3-5 dpi. To determine the function of LIF, we performed a LIF knockdown experiment using LIF-specific antisense morpholino oligonucleotides (LIF MOs. LIF MOs, which were introduced into zebrafish RGCs via a severed optic nerve, reduced the expression of LIF and abrogated the activation of STAT3 in RGCs after injury. These results suggest that upregulated LIF drives Janus kinase (Jak/STAT3 signaling in zebrafish RGCs after nerve injury. In addition, the LIF knockdown impaired axon sprouting in retinal explant culture in vitro; reduced the expression of a regeneration-associated molecule, growth-associated protein 43 (GAP-43; and delayed functional recovery after optic nerve injury in vivo. In this study, we comprehensively demonstrate the beneficial role of LIF in optic nerve regeneration and functional recovery in adult zebrafish.

  19. LIF is a contraction-induced myokine stimulating human myocyte proliferation

    DEFF Research Database (Denmark)

    Broholm, Christa; Laye, Matthew J; Brandt, Claus

    2011-01-01

    Background: The cytokine leukemia inhibitory factor (LIF) is expressed by skeletal muscle and induces proliferation of myoblasts. We hypothesized that LIF is a contraction-induced myokine functioning in an autocrine fashion to activate gene regulation of human muscle satellite cell proliferation....... Methods: Skeletal muscle LIF expression, regulation and action were examined in two models: 1) Young men performing a bout of heavy resistance exercise of the quadriceps muscle and 2) cultured primary human satellite cells. Results: Resistance exercise induced a 9-fold increase in LIF mRNA content...... in skeletal muscle, but LIF was not detectable in plasma of the subjects. However, electrically stimulated cultured human myotubes produced and secreted LIF, suggesting that LIF is a myokine with local effects. The well-established exercise-induced signaling molecules PI3K, Akt and mTor contributed...

  20. LIF Measurement of Interacting Gas Jet Flow with Plane Wall

    Science.gov (United States)

    Yanagi, A.; Kurihara, S.; Yamazaki, S.; Ota, M.; Maeno, K.

    2011-05-01

    Discharging rarefied gas jets in low-pressure conditions are interesting and important phenomena from an engineering point of view. For example they relate to the attitude control of the space satellite, or the semiconductor technology. The jets, however, deform to the complicated shapes by interacting with solid walls. In this paper we have performed the experiments the flow visualization as a first step by applying the LIF (Laser Induced Fluorescence) method on the jet-wall interaction. Jet is spouting out from a φ1.0 mm circular hole into the low pressure air chamber, impinging on a flat plate. The LIF visualization of interacting rarefied gas jet is carried out by using the iodine (I2) tracer and argon ion laser.

  1. LIF-Free Embryonic Stem Cell Culture in Simulated Microgravity

    OpenAIRE

    Yumi Kawahara; Tomotaka Manabe; Masaya Matsumoto; Teruyuki Kajiume; Masayasu Matsumoto; Louis Yuge

    2009-01-01

    BACKGROUND: Leukemia inhibitory factor (LIF) is an indispensable factor for maintaining mouse embryonic stem (ES) cell pluripotency. A feeder layer and serum are also needed to maintain an undifferentiated state, however, such animal derived materials need to be eliminated for clinical applications. Therefore, a more reliable ES cell culture technique is required. METHODOLOGY/PRINCIPAL FINDINGS: We cultured mouse ES cells in simulated microgravity using a 3D-clinostat. We used feeder-free and...

  2. INVESTIGATION OF CE/LIF AS A TOOL IN THE ...

    Science.gov (United States)

    The investigation of emerging contaminant issues is a proactive effort in environmental analysis. As a part of this effort, sewage effluent is of current analytical interest because of the presence of pharmaceuticals and their metabolites and personal care products The environmental impact of these components is still under investigation but their constant perfusion into receiving waters and their potential effect on biota is of concern. This paper examines a tool for the characterization of sewage effluent using capillary electrophoresis/laser-induced fluorescence (CE/LIF) with a frequency-doubled laser operated in the ultraviolet (UV). Fluorescent acidic analytes are targeted because they present special problems for techniques such as gas chromatography/mass spectrometry (GC/MS) but are readily accessible to CE/LIF. As an example of the application of this tool, salicylic acid is determined near the 100 ng/L level in sewage effluent. Salicylic acid is a metabolite of various analgesics Relatively stable in the environment, it is a common contaminant of municipal sewage systems. Salicylic acid was recovered from freshly collected samples of the effluent by liquid-liquid extraction as part of a broad characterization effort. Confirmation of identity was by electron ionization GC/MS after conversion of the salicylic acid to the methyl ester by means of trimethylsilyidiazomethane CE/LIF in the UV has revealed more than 50 individual peaks in the extract and a bac

  3. Design of MagLIF experiments using the Z facility

    Science.gov (United States)

    Sefkow, Adam

    2013-10-01

    The MagLIF (Magnetized Liner Inertial Fusion) concept has been presented as a path toward obtaining substantial fusion yields using the Z facility, and related experiments have begun in earnest at Sandia National Laboratories. We present fully integrated numerical magnetohydrodynamic simulations of the MagLIF concept, which include laser preheating of the fuel, the presence of electrodes, and end loss effects. These simulations have been used to design neutron-producing integrated MagLIF experiments on the Z facility for the capabilities that presently exist, namely, D2 fuel, peak currents of Imax 15-18 MA, pre-seeded axial magnetic fields of Bz0 = 7-10 T, and laser preheat energies of Elaser = 2-3 kJ delivered in 2 ns. The first fully integrated experiments, based on these simulations, are planned to occur in 2013. Neutron yields in excess of 1011 are predicted with the available laser preheat energy and accelerator drive energy. In several years, we plan to upgrade the laser to increase Elaser = by several more kJ, provide Bz0 up to 30 T, deliver Imax 22 MA or more to the load, and develop the capability to use DT fuel. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Localized transitions in the thermoluminescence of LiF : Mg,Ti: potential for nanoscale dosimetry

    CERN Document Server

    Horowitz, Y S; Biderman, S; Einav, Y

    2003-01-01

    We describe the effect of nanoscale spatially coupled trapping centre (TC)-luminescent centre (LC) pairs on the thermoluminescence (TL) properties of LiF : Mg,Ti. It is shown that glow peak 5a (a low-temperature satellite of the major glow peak 5) arises from localized electron-hole (e-h) recombination in a TC-LC pair believed to be based on Mg sup 2 sup + -Li sub v sub a sub c trimers (the TCs) coupled to Ti(OH) sub n molecules (the LCs). Due to the localized nature of the e-h pair, two important properties are affected: (i) heavy charged particle (HCP) TL efficiency: the intensity of peak 5a relative to peak 5 following HCP high-ionization density irradiation is greater than that following low ionization density irradiation in a manner somewhat similar to the ionization density dependence of the yield of double-strand breaks (DSBs) induced in DNA. Our experimental measurements in a variety of HCP and fast neutron radiation fields have demonstrated that the ratio of glow peaks 5a/5 is nearly independent of p...

  5. Effect of LiF on Densification and Mechanical Properties of Dy-α-Sialon Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effect of LiF on the densification and mechanical properties of hot-pressed Dy-α-sialon ceramics was studied. Comparatively, without LiF as sintering additive, the pure Dy-α-sialon ceramic should be sintered at 1750 ℃. When LiF is used, the sintering temperature of the Dy-α-sialon is greatly lowered to 1500~1650 ℃. Obviously, the addition of LiF has a strong effect on the improvement in densification. Meanwhile, the resultant Dy-α-sialon has no significant changes in the mechanical properties.

  6. Normalized Design of Multi-channel LIF Digital Receiver

    Institute of Scientific and Technical Information of China (English)

    方航锋; 郁发兴; 汪海航

    2004-01-01

    A design method for parallel processing application on multi-channel low-intermediate-frequency(LIF) digital receiver was presented. It is based on the DSP sub-array with a simple topology and operation timing to evaluate and determine the processing capability and then construct the parallel processing array for multi-channel signals according to the restriction of operation timing. Using this method, the design of multi-channel digital receiver may be simplified. Finally, a design example was used to show how to apply this method.

  7. LIF characterization of ancient umber ceramics and frescos; Applicazione della tecnica LIF alle antiche ceramiche umbre e agli affreschi

    Energy Technology Data Exchange (ETDEWEB)

    Fantoni, R.; Palucci, A.; Ribezzo, S. [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Borgia, I. [Perugia Univ., Perugia (Italy)

    1999-07-01

    The report shows the result carried out by the LIF (layer induced fluorescence) system developed for pigment analysis at ENEA (National Agency for New Technology, Energy and the Environment) Frascati research centre (Rome) . The frescos and ceramics by Umbria region (Italy) are analysed. [Italian] Vengono riportati i risultati ottenuti dall'indagine della fluorescenza indotta da laser su antiche ceramiche umbre e su affreschi. La tecnica e' stata anche utilizzata per determinare la fluorescenza dei pigmenti contenuti in campioni di affresco.

  8. The interaction of atoms with LiF(001) revisited

    CERN Document Server

    Miraglia, J E

    2016-01-01

    Pairwise additive potentials for multielectronic atoms interacting with a LiF(001) surface are revisited by including an improved description of the electron density associated with the different lattice sites, as well as non-local electron density contributions. Within this model, the electron distribution around each ionic site of the crystal is described by means of an onion approach that accounts for the influence of the Madelung potential. From such densities, binary interatomic potentials are then derived by using well-known non-local functionals for the kinetic, exchange and correlation terms. Rumpling and long-range contributions due to projectile polarization and van der Waals forces are also included in an analogous fashion. We apply this pairwise additive approximation to evaluate the interaction potential between closed-shell - He, Ne, Ar, Kr, and Xe - and open-shell - N, S, and Cl - atoms and the LiF surface, analyzing the relative importance of the different contributions. The performance of the...

  9. Determination of flame temperature using laser induced fluorescence (LIF)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Lina Augusta Martins Ramos da [Instituto Tecnologico de Aeronautica (ITA/DCTA), Sao Jose dos Campos, SP (Brazil); Barreta, Gilberto; Carinhana Junior, Dermeval; Toledo, Antonio Osny de [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil)

    2011-07-01

    Full text: Laser Induced Fluorescence, LIF, is one of the most used techniques in combustion diagnostics. The excitation method is based on the spontaneous spectrum from atoms or molecules that were excited by laser radiation. In general, intermediated combustion species, as OH and CH radicals, are used as temperature probes. Usually, several rotational levels are used by tuning the laser afterwards across the corresponding absorption transitions. The emission spectrum is detected in a convenient spectral range. The accuracy of measurements depends on the laser linewidth, the delay between the laser excitation and spectra detection and, mainly, the spectral interval of laser excitation. In this work, OH LIF spectra from stoichiometric LPG (Liquefied Petroleum Gas) flames were obtained using a tuned laser with a spectral range set from 282 nm up to 283 nm. This corresponds to the rotation levels of the 0-1 vibration band of OH radical. The laser energy was ca. 0.2 mJ. The emission spectrum was collected in the spectral range of the 305-310 nm, which corresponds to the region of the 0-0 band. The temperature was determined by the Boltzmann method. This is based on the measurement of the relative peak intensities of the emission spectrum. A plot of natural logarithm of line intensities versus energy level returns a straight line, whose slope is the inverse of the rotational temperature. The flame temperature was ca. 2300 K. This value is consistent with previous results obtained in our laboratory. (author)

  10. Laser heating challenges of high yield MagLIF targets

    Science.gov (United States)

    Slutz, Stephen; Sefkow, Adam; Vesey, Roger

    2014-10-01

    The MagLIF (Magnetized Liner Inertial Fusion) concept is predicted by numerical simulation to produce fusion yields of about 100 kJ, when driven by 25 MA from the existing Z accelerator [S. A. Slutz et al. Phys. Plasmas 17, 056303 (2010)] and much higher yields with future accelerators delivering higher currents [Slutz and Vesey PRL 108, 025003 (2012)]. The fuel must be heated before compression to obtain significant fusion yields due to the relatively slow implosion velocities (~ 100 km/s) of magnetically driven liners. Lasers provide a convenient means to accomplish this pre-compressional heating of the fusion fuel, but there are challenges. The laser must penetrate a foil covering the laser entrance hole and deposit 20-30 kJ within the ~1 cm length of the liner in fuel at 6-12 mg/cc. Such high densities could result in beam scattering due to refraction and laser plasma interactions. Numerical simulations of the laser heating process are presented, which indicate that energies as high as 30 kJ could be deposited in the fuel by using two laser pulses of different wavelengths. Simulations of this process will be presented as well of results for a MagLIF design for a potential new machine delivering 50 MA of current. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  11. Neutron Measurements in Small MagLIF Experiments on OMEGA

    Science.gov (United States)

    Glebov, V. Yu.; Barnak, D. H.; Davies, J. R.; Knauer, J. P.; Betti, R.; Regan, S. P.; Sangster, T. C.; Campbell, E. M.

    2016-10-01

    The Laboratory for Laser Energetics (LLE) is participating in laser-driven magnetized linear inertial fusion (MagLIF) research on the OMEGA Laser System in partnership with Sandia as part of ARPA-E's ALPHA Program. In the current OMEGA setup, a CH cylindrical tube filled with D2 gas is compressed by 40 laser beams, preheated by one of the beams, and an axial magnetic field is applied to limit electron heat loss. Two copper coils provide 10-T magnetic fields. A neutron time-of-flight (nTOF) detector has been designed, fabricated, and calibrated to diagnose primary D-D fusion neutron yield in the range of 1 ×107 to 5 ×109 and ion temperature from 2 to 8 keV. The design details and calibration results of these nTOF detectors will be presented together with neutron measurement results from recent laser-driven MagLIF experiments on OMEGA. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000568, and the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  12. Two-dimensional thermoluminescence method for checking LiF crystals homogeneity

    Science.gov (United States)

    Marczewska, B.; Bilski, P.; Gieszczyk, W.; Kłosowski, M.

    2017-01-01

    Thermoluminescence (TL), being one of the common luminescence methods, is very sensitive to the presence of any impurities in the material structure and can be used for the detection of impurity distribution in the bulk of the crystal. If in a TL reader a CCD camera is used, a measurement of TL signal would give us an unique two-dimensional (2-D) imaging of TL signal distribution, and thereby the distribution of dopants. The possibility of the application of 2-D TL method for the control of uniformity of the crystal related to dopant distribution in the volume of the bulk crystal was tested on the large area samples of LiF doped and un-doped crystals grown by Czochralski method at the IFJ PAN in Kraków. The special TL reader with a CCD camera was used for analyzing of luminescence emitting during the heating of the irradiated in uniform radiation field slices of crystals cut longitudinal and perpendicular to the growth axis and for analyzing of the shape of TL glow curves for selected crystal areas. Non-uniform distribution of the dopants was demonstrated for doped crystal grown with relatively slow growth rate.

  13. Multiple Sclerosis and the LIF/IL-6 Axis: Use of Nanotechnology to Harness the Tolerogenic and Reparative Properties of LIF

    Directory of Open Access Journals (Sweden)

    Su M. Metcalfe

    2015-05-01

    tions for the treatment of autoimmune diseases, where the clinical burden is immense. It encompasses more than 100 diseases and, in the USA alone, costs more than $100 billion in direct health care costs annually. Other properties of LIF include the promotion of healthy neuro-glial interactions within the central nervous system (CNS, where, in addition to MS, LIF-NP therapy is relevant to inflammatory neurodegenerative diseases that represent a large and increasing need within aging populations. Thirdly, LIF is a reparative growth factor that can maintain genomic plasticity. LIF-NP supports the use of stem cell-based therapies in regenerative medicine plus augment thera‐ peutic benefits within the patient. These core properties of LIF are greatly amplified in value by the advantage of being formulated as nanoparticles, namely (i targeted delivery, (ii exploitation of endogenous regulatory pathways and (iii creation of surrogate micro-stromal niches. We discuss LIF-NP as a means to harness endogenous pathways for the treatment of MS, both to reset immune self-tolerance and to promote repair of myelin that is required to support health within the nervous system.

  14. Design of a Real-time Signal Processing System for LIF Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xiande; Zheng Wengang; Dong Daming; Shen Changjun; Zhang Xin; Zhou Jianjun; Yan Hua; Wu Wenbiao, E-mail: zhengwg@nercita.org.cn [National Engineering Research Center for Information Technology in Agriculture, 100097 (China)

    2011-02-01

    Laser Induced Fluorescence (LIF) sensor is one of the most sensitive approaches available for a variety of analytical applications, such as determination of nitrogen content of plant leaves, detection of chlorophyll content in water, etal. As a core instrumental requirements of real time LIF sensor, signal processing system is used to store effective processing and identification algorithms in a short time. By analyzing the working principle of LIF sensor in detail, a novel platform of signal processing system used in LIF sensor is proposed in this paper. The design solutions and hardware architecture of the system are described in this paper, include Digital Signal Processor (DSP), data transmission block, and memory block. Several steps of signal processing methods are proposed, according to the characteristic of LIF sensor. At last, an application of using the signal processing system designed in this paper for measuring chlorophyll content in plant leaves is shown.

  15. LiF crystals as high spatial resolution neutron imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Matsubayashi, M., E-mail: matsubayashi.masahito@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Shirane 2-4, Shirakata, Tokai, Ibaraki 319-1195 (Japan); Faenov, A.; Pikuz, T. [Joint Institute for High Temperatures of Russian Academy of Sciences, Izhorskaja Street 13/19, Moscow (Russian Federation); Fukuda, Y. [Kansai Photon Science Institute, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Kato, Y. [The Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Yasuda, R.; Iikura, H.; Nojima, T.; Sakai, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Shirane 2-4, Shirakata, Tokai, Ibaraki 319-1195 (Japan)

    2011-09-21

    Neutron imaging by color center formation in LiF crystals was applied to a sensitivity indicator (SI) as a standard samples for neutron radiography. The SI was exposed to a 5 mm pinhole-collimated thermal neutron beam with an LiF crystal and a neutron imaging plate (NIP) for 120 min in the JRR-3M thermal neutron radiography facility. The image in the LiF crystal was read out using a laser confocal microscope. All gaps were clearly observed in images for both the LiF crystal and the NIP. The experimental results showed that LiF crystals have excellent characteristics as neutron imaging detectors in areas such as high spatial resolution.

  16. The hnRNP-Q protein LIF2 participates in the plant immune response.

    Directory of Open Access Journals (Sweden)

    Clémentine Le Roux

    Full Text Available Eukaryotes have evolved complex defense pathways to combat invading pathogens. Here, we investigated the role of the Arabidopsis thaliana heterogeneous nuclear ribonucleoprotein (hnRNP-Q LIF2 in the plant innate immune response. We show that LIF2 loss-of-function in A. thaliana leads to changes in the basal expression of the salicylic acid (SA- and jasmonic acid (JA- dependent defense marker genes PR1 and PDF1.2, respectively. Whereas the expression of genes involved in SA and JA biosynthesis and signaling was also affected in the lif2-1 mutant, no change in SA and JA hormonal contents was detected. In addition, the composition of glucosinolates, a class of defense-related secondary metabolites, was altered in the lif2-1 mutant in the absence of pathogen challenge. The lif2-1 mutant exhibited reduced susceptibility to the hemi-biotrophic pathogen Pseudomonas syringae and the necrotrophic ascomycete Botrytis cinerea. Furthermore, the lif2-1 sid2-2 double mutant was less susceptible than the wild type to P. syringae infection, suggesting that the lif2 response to pathogens was independent of SA accumulation. Together, our data suggest that lif2-1 exhibits a basal primed defense state, resulting from complex deregulation of gene expression, which leads to increased resistance to pathogens with various infection strategies. Therefore, LIF2 may function as a suppressor of cell-autonomous immunity. Similar to its human homolog, NSAP1/SYNCRIP, a trans-acting factor involved in both cellular processes and the viral life cycle, LIF2 may regulate the conflicting aspects of development and defense programs, suggesting that a conserved evolutionary trade-off between growth and defense pathways exists in eukaryotes.

  17. Electronic stopping power in LiF from first principles.

    Science.gov (United States)

    Pruneda, J M; Sánchez-Portal, D; Arnau, A; Juaristi, J I; Artacho, Emilio

    2007-12-07

    Using time-dependent density-functional theory we calculate from first principles the rate of energy transfer from a moving proton or antiproton to the electrons of an insulating material, LiF. The behavior of the electronic stopping power versus projectile velocity displays an effective threshold velocity of approximately 0.2 a.u. for the proton, consistent with recent experimental observations, and also for the antiproton. The calculated proton/antiproton stopping-power ratio is approximately 2.4 at velocities slightly above the threshold (v approximately 0.4 a.u.), as compared to the experimental value of 2.1. The projectile energy loss mechanism is observed to be extremely local.

  18. Near-infrared LIF spectroscopy of HfF

    CERN Document Server

    Grau, Matt; Loh, Huanqian; Sinclair, Laura C; Stutz, Russel P; Yahn, Tylser S; Cornell, Eric A

    2012-01-01

    The molecular ion HfF$^+$ is the chosen species for a JILA experiment to measure the electron electric dipole moment (eEDM). Detailed knowledge of the spectrum of HfF is crucial to prepare HfF$^+$ in a state suitable for performing an eEDM measurement\\cite{Leanhardt}. We investigated the near-infrared electronic spectrum of HfF using laser-induced fluorescence (LIF) of a supersonic molecular beam. We discovered eight unreported bands, and assign each of them unambiguously, four to vibrational bands belonging to the transition $[13.8]0.5 \\leftarrow X1.5$, and four to vibrational bands belonging to the transition $[14.2]1.5 \\leftarrow X1.5$. Additionally, we report an improved measurement of vibrational spacing of the ground state, as well as anharmonicity $\\omega_e x_e$.

  19. Establishment of an exogenous LIF-free culture system for mouse embryonic stem cells.

    Science.gov (United States)

    Feng, Shumei; Mo, Lijuan; Wu, Rongrong; Chen, Xiaopan; Zhang, Ming

    2009-09-01

    Mouse embryonic stem cells (mESCs) have played a key role in the newly emerging fields of stem cell research. The traditional derivation and culture of mESCs have been based on the use of mouse embryonic fibroblasts (MEFs) treated with exogenous leukemia inhibitory factor (LIF). However, the rapid senescence of MEFs, coupled with the high cost of LIF, has significantly hampered the widespread use of mESCs in stem cell research. Thus, we present a novel exogenous LIF-free culture system for general mESCs applications, comprising fibroblast-like cells derived from the rabbit spleen (RSFs). We demonstrated that mESCs cultured on RSFs (mESCs-RSFs) maintained all mESC features after prolonged LIF-free culture, including alkaline phosphatase, cell surface markers (SSEA-1), molecular markers (OCT-4, NANOG, TERT, REX-1), karyotype, and pluripotency. The high expression level of both LIF and WNT3A in the RSFs may account for their ability to maintain mESCs without exogenous LIF. Moreover, this exogenous LIF-free culture system was verified to be of microbiological quality through analysis with electron transmission microscopy.

  20. Studying the Attribution of LiF in OLED by the - Characteristics

    Directory of Open Access Journals (Sweden)

    Chun-lin Zhang

    2010-01-01

    Full Text Available The organic light-emitting device (OLED with simple structures of indium tin oxide (ITO/tris(8-quinolinolato aluminum (Alq3/LiF/Al and ITO/Alq3/Al was fabricated to analyze the contribution of LiF in OLED. We used the - characteristics to investigate the contribution of LiF in OLED and found that the capacitance of the above-mentioned structures was 12.5 nF and 77.5 nF, respectively. It is shown that the LiF layer affects the property of OLED resulting in the change of the capacitance of the device.

  1. Effect of LiF on the Optical Transmittance of Magnesium Aluminate Spinel

    Institute of Scientific and Technical Information of China (English)

    LI Fahui; LIN Hong; LI Jianbao; LEI Muyun; HUANG Cunxin; WEN Fang

    2012-01-01

    The effect of LiF as a sintering aid to the optical transparency of magnesium aluminate (MgAl2O4) spinel ceramics is studied.The spinel ceramics is prepared in a process proved to be suitable for commercial production.LiF,in different concentrations ranging from 0-2.5 wt%,is doped into MgAl2O4powders prepared by sol-gel method.Sample MgAl2O4 ceramic discs are fabricated by ball milling,cold pressing,and hot-pressing,or hot-isostatic-pressing of the powder mixtures.Optical transparency measurements show that,hot-pressed samples exhibit higher transparency when more LiF is added,While for hot-isostatic pressed samples,excessive LiF content leads to a decrease in optical transparency.The optimal LiF doping quantity is suggested for the present technique.

  2. Reliable LIF/Mie droplet sizing in sprays using structured laser illumination planar imaging.

    Science.gov (United States)

    Mishra, Yogeshwar Nath; Kristensson, Elias; Berrocal, Edouard

    2014-02-24

    In this article, Structured Laser Illumination Planar Imaging (SLIPI) is used in combination with the LIF/Mie ratio technique for extracting a reliable two-dimensional mapping of the droplets Sauter Mean Diameter (SMD). We show that even for the case of a fairly dilute spray, where single scattering events are in majority, the conventional LIF/Mie technique still remains largely affected by errors introduced by multiple light scattering. To remove this unwanted light intensity on both the LIF and Mie images SLIPI is used prior to apply the image ratio. For the first time, the SLIPI LIF/Mie results are calibrated and compared with measurement data from Phase Doppler Interferometry (PDI).

  3. Electron micrography and x-ray study of dip-lacquered LiF (220)

    DEFF Research Database (Denmark)

    Palmari, J.; Rasigni, M.; Rasigni, G.;

    1991-01-01

    It has been proposed to use the 220 reflection of LiF with a multilayer deposited upon the top for simultaneous spectroscopy near Fe-k and O-k and below the C-k absorption edge (284 eV) in x-ray astronomy. We demonstrate that a substantial reduction of surface roughness is obtained by dip...... lacquering state-of-the-art polished LiF(220) surfaces. Using a microdensitometer analysis of electron micrographs of surface replicas and x-ray reflection, we have measured ∼ 10-Å rms roughness of Au-coated dip-lacquered LiF(220) crystals, as opposed to ∼ 60 Å measured on the bare LiF(220) crystal surface....

  4. Study of T L LiF: Mg,Ti (Model JR1152C) material for its use in the environmental monitoring; Estudio del material TL LiF: Mg, Ti (JR1152C) para su empleo en el monitoreo ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Diaz B, E.; Prendes A, M. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo. postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

    1999-07-01

    In order to evaluate the possibility to use the T L material of LiF: Mg,Ti (Model JR1152C) as environmental dosemeter it was realized its characterization of it according to the established criterion in the standard IEC-1066. The properties studied were: homogeneity of the lot, reproducibility, response linearity, detection threshold, auto irradiation, residual signal, response pride (fading) and angular dependence. The results prove the compliment of the IEC requirements and therefore the applicability of this dosemeter in the environmental monitoring. (Author)

  5. Window decompression in laser-heated MagLIF targets

    Science.gov (United States)

    Woodbury, Daniel; Peterson, Kyle; Sefkow, Adam

    2015-11-01

    The Magnetized Liner Inertial Fusion (MagLIF) concept requires pre-magnetized fuel to be pre-heated with a laser before undergoing compression by a thick solid liner. Recent experiments and simulations suggest that yield has been limited to date by poor laser preheat and laser-induced mix in the fuel region. In order to assess laser energy transmission through the pressure-holding window, as well as resultant mix, we modeled window disassembly under different conditions using 1D and 2D simulations in both Helios and HYDRA. We present results tracking energy absorption, time needed for decompression, risk of laser-plasma interaction (LPI) that may scatter laser light, and potential for mix from various window thicknesses, laser spot sizes and gas fill densities. These results indicate that using thinner windows (0.5-1 μm windows) and relatively large laser spot radii (600 μm and above) can avoid deleterious effects and improve coupling with the fuel. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under DE-AC04- 94AL85000.

  6. LIF Diagnostic for Measuring Beam-Transport Magnetic Fields

    Science.gov (United States)

    Jones, T. G.; Hinshelwood, D. D.; Neri, J. M.; Ottinger, P. F.; Noonan, W. A.

    1997-11-01

    A novel, spatially-resolved diagnostic is being developed to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as is envisioned for light ion-driven ICF. The diagnostic technique uses laser-induced fluorescence (LIF) spectroscopy, and can be varied to measure either small or large fields. Small fields, as expected in ballistic transport with solenoidal lens focusing using ~ 1 Torr gas, produce Zeeman shifts, Δ λ_Z, smaller than the transition linewidth, Δ λ. High sensitivity to measure these shifts is achieved by a variation on the Babcock technique.^1 Large fields, as expected in self-pinched transport using 1--100 mTorr gas, produce Δ λZ larger than Δ λ. These Δ λZ will be resolved using an etalon as a narrowband, high-throughput optical filter. Available results from benchtop experiments using calibrated B-fields for both the small- and large-field techniques, and progress in fielding this diagnostic on the Gamble-II accelerator for beam-transport studies will be presented. Work supported by DOE through Sandia National Laboratories. ^ National Research Council Research Associate. ^ Present address University of Maryland, College Park, MD. ^1 W.A. Noonan, et al., Rev. Sci. Instrum. 68, 1032 (1997).

  7. First Scaled-Down Integrated MagLIF Experiments on OMEGA

    Science.gov (United States)

    Davies, J. R.; Barnak, D. H.; Betti, R.; Glebov, V. Yu.; Knauer, J. P.; Regan, S. P.

    2016-10-01

    Magnetized liner inertial fusion (MagLIF) is an inertial confinement fusion (ICF) scheme that relies on compression of a cylindrical, magnetized, preheated plasma to achieve fusion conditions with a lower implosion velocity and a lower convergence ratio than conventional ICF. MagLIF research to date has been centered on the Z pulsed-power machine at Sandia National Laboratories-the only facility capable of carrying out such experiments. A laser-driven version of MagLIF has now been implemented on the OMEGA laser at the Laboratory for Laser Energetics, using targets roughly ten times smaller in linear dimensions than Z targets. Laser-driven MagLIF on OMEGA will test the scaling of MagLIF and provide a higher shot rate with better diagnostic access than Z. Preliminary results from integrated MagLIF experiments on OMEGA will be presented for the first time. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000568, and the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  8. Three-Dimensional Conformal Radiotherapy in Prostate Cancer Patients: Rise in Interleukin 6 (IL-6) but not IL-2, IL-4, IL-5, Tumor Necrosis Factor-{alpha}, MIP-1-{alpha}, and LIF Levels

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Lopes, Carlos [Universidade do Vale do Paraiba, Centro de Oncologia Radioterapica do Vale do Paraiba, Universidade do Vale do Paraiba Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Sao Jose dos Campos, Sao Paulo (Brazil); Callera, Fernando, E-mail: fcallera@gmail.com [Centro de Hematologia Onco-hematologia e Transplantes de Medula Ossea do Vale do Paraiba, Sao Paulo (Brazil)

    2012-03-15

    Purpose: To investigate the effect of radiotherapy (RT) on serum levels of interleukin-2 (IL-2), IL-4, IL-5, IL-6, tumor necrosis factor alpha (TNF-{alpha}), macrophage inflammatory protein-1-alpha (MIP-1-{alpha}) and leukemia inhibitory factor (LIF) in patients with prostate cancer. Methods and Materials: Forty eight patients with prostate cancer received three-dimensional conformal blocking radiation therapy with a linear accelerator. IL-2, IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were measured by the related immunoassay kit 1 day before the beginning of RT and during RT at days 15 and 30. Results: The mean IL-2 values were elevated before and during the RT in contrast with those of IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF, which were within the normal range under the same conditions. Regarding markers IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF, comparisons among the three groups (before treatment and 15 and 30 days during RT) did not show significant differences. Although values were within the normal range, there was a significant rise in IL-6 levels at day 15 of RT (p = 0.0049) and a decline at day 30 to levels that were similar to those observed before RT. Conclusions: IL-6 appeared to peak after 15 days of RT before returning to pre-RT levels. In contrast, IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were not sensitive to irradiation. The increased levels of IL-6 following RT without the concurrent elevation of other cytokines involved in the acute phase reaction did not suggest a classical inflammatory response to radiation exposure. Further studies should be designed to elucidate the role of IL-6 levels in patients with prostate cancer treated with RT.

  9. Quantum Chemical Insight into the LiF Interlayer Effects in Organic Electronics: Reactions between Al Atom and LiF Clusters.

    Science.gov (United States)

    Wu, Shui-Xing; Kan, Yu-He; Li, Hai-Bin; Zhao, Liang; Wu, Yong; Su, Zhong-Min

    2015-08-06

    It is well known that the aluminum cathode performs dramatically better when a thin lithium fluoride (LiF) layer inserted in organic electronic devices. The doping effect induced by the librated Li atom via the chemical reactions producing AlF3 as byproduct was previously proposed as one of possible mechanisms. However, the underlying mechanism discussion is quite complicated and not fully understood so far, although the LiF interlayer is widely used. In this paper, we perform theoretical calculations to consider the reactions between an aluminum atom and distinct LiF clusters. The reaction pathways of the Al-(LiF)n (n = 2, 4, 16) systems were discovered and the energetics were theoretically evaluated. The release of Li atom and the formation of AlF3 were found in two different chemical reaction routes. The undissociated Al-(LiF)n systems have chances to change to some structures with loosely bound electrons. Our findings about the interacted Al-(LiF)n systems reveal new insights into the LiF interlayer effects in organic electronics applications.

  10. Development of a cryogenically cooled platform for the Magnetized Liner Inertial Fusion (MagLIF) Program

    Science.gov (United States)

    Awe, T. J.; Shelton, K. P.; Sefkow, A. B.; Lamppa, D. C.; Baker, J. L.; Rovang, D. C.; Robertson, G. K.

    2017-09-01

    A cryogenically cooled hardware platform has been developed and commissioned on the Z Facility at Sandia National Laboratories in support of the Magnetized Liner Inertial Fusion (MagLIF) Program. MagLIF is a magneto-inertial fusion concept that employs a magnetically imploded metallic tube (liner) to compress and inertially confine premagnetized and preheated fusion fuel. The fuel is preheated using a ˜2 kJ laser that must pass through a ˜1.5-3.5-μm-thick polyimide "window" at the target's laser entrance hole (LEH). As the terawatt-class laser interacts with the dense window, laser plasma instabilities (LPIs) can develop, which reduce the preheat energy delivered to the fuel, initiate fuel contamination, and degrade target performance. Cryogenically cooled targets increase the parameter space accessible to MagLIF target designs by allowing nearly 10 times thinner windows to be used for any accessible gas density. Thinner LEH windows reduce the deleterious effects of difficult to model LPIs. The Z Facility's cryogenic infrastructure has been significantly altered to enable compatibility with the premagnetization and fuel preheat stages of MagLIF. The MagLIF cryostat brings the liquid helium coolant directly to the target via an electrically resistive conduit. This design maximizes cooling power while allowing rapid diffusion of the axial magnetic field supplied by external Helmholtz-like coils. A variety of techniques have been developed to mitigate the accumulation of ice from vacuum chamber contaminants on the cooled LEH window, as even a few hundred nanometers of ice would impact laser energy coupling to the fuel region. The MagLIF cryostat has demonstrated compatibility with the premagnetization and preheat stages of MagLIF and the ability to cool targets to liquid deuterium temperatures in approximately 5 min.

  11. Dosimetric intercomparison in Cobalt 60 unities using TLD-100 crystals and CaSO{sub 4}: Dy + Ptfe; Intercomparacion dosimetrica en unidades de cobalto 60 usando cristales de TLD-100 y CaSO{sub 4}: Dy + PTFE

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E. [Universidad Autonoma Metropolitana Xochimilco, Mexico D.F. (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana Iztapalapa, Mexico D.F. (Mexico); Perez P, M.A. [Instituto Nacional de Cancerologia, Mexico D.F. (Mexico); Castillo H, M. [Centro Medico Nacional 20 de Noviembre, ISSSTE, Mexico D.F. (Mexico); Flores F, F. [Unidad de Oncologia, Centro Medico Nacional, IMSS, Mexico D.F. (Mexico); Guzman R, L.V. [Unidad de Oncologia, Hospital General de Mexico, Mexico D.F. (Mexico)

    1999-07-01

    The purpose of this work is to design and construct a phantom in basis of thermoplastic polymer of methyl methacrylate that is reutilizable and which allows to do an analysis of the absorbed doses in thermoluminescent crystals (Tl) exposed to cobalt 60 to establish the dosimetric intercomparison in cobalt units which allows to do the follow-up of the Quality assurance programs, standardization of calibration procedures, dosimetry and TLD post intercomparison in radiotherapy. This work allows also prove new thermoluminescent materials of national manufacture developed by Juan Azorin and collaborators as the CaSO{sub 4}: Dy + Ptfe. This is a first study which is realized in Mexico with the system crystal-phantom for aims to intercomparison in cobalt 60 units. In this work participate eight unities of cobalt 60 of different trades belonging at four radiotherapy centers. The results of the dose intercomparison of the eight unities of cobalt 60 were in the range 0.95-1.13, taking in account that the values between 0.95 and 1.05 were considered acceptable in terms of the requirements by the standing legislation. (Author)

  12. Thermal neutron response and theoretical comparison of LiF coated aluminized Mylar

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu; Bellinger, Steven L.; Edwards, Nathaniel S.; Montag, Benjamin W.; Schmidt, Aaron J.; Wayant, Clayton; McGregor, Douglas S.

    2014-10-21

    Thin layers of LiF were deposited on a 2.0 µm thick aluminized BoPET (i.e. Mylar) in thicknesses of 4.5, 9.9, and 14.0 µm using an electron beam evaporator. These coatings were thinner than the summed triton and alpha particle range from the {sup 6}Li(n,t){sup 4}He reaction, which allows both particles to escape a suspended absorber sheet simultaneously and measured in a proportional gas region concurrently. Each thickness of the LiF coated Mylar sheets were positioned separately in a test chamber that had a single anode wire positioned on each side of the absorber sheets. The thermal neutron response pulse-height spectra were collected for each LiF thickness and are presented and discussed. The coatings became fragile at thicknesses greater than 5.0 µm and would flake off of the Mylar sheets. Additionally, the ideal LiF coating thickness that maximizes the intrinsic thermal neutron detection efficiency is greater than 5.0 µm, which is discussed in a greater detail in the text. Overall, the detectors are capable of achieving thermal-neutron detection efficiencies greater than 30% for a 5 layer device and 60 % for 20 layers, but these devices are complex to fabricate due to flaking of the LiF coatings. Additional research is required to eliminate flaking by possibly using additional mechanical structures or adhesive materials.

  13. Triton and alpha-particle contribution from LiF converter for neutron dosimeter

    CERN Document Server

    Camacho, M E; Balcazar, M

    1999-01-01

    A personnel neutron dosimeter prototype based on chemical and electrochemical etched CR-39 detector, combined with LiF converter, has been calibrated using an ICRP-like phantom, under a heavy-water moderated Californium source neutron spectra; A conversion factor of 1.052+-126 spots cm sup - sup 2 mSv sup - sup 1 was obtained. The sealing properties of the detector holder showed a ten-fold reduction in radon background when it was tested in a high radon atmosphere. A convenient mechanical shock resistance was achieved in LiF converters by sintering to 11 tons pressure LiF powder at 650 deg. C, during one hour.

  14. CD133+ adult human retinal cells remain undifferentiated in Leukaemia Inhibitory Factor (LIF

    Directory of Open Access Journals (Sweden)

    Mayer Eric J

    2009-02-01

    Full Text Available Abstract Background CD133 is a cell surface marker of haematopoietic stem and progenitor cells. Leukaemia inhibitory factor (LIF, sustains proliferation and not differentiation of embryonic stem cells. We used CD133 to purify adult human retinal cells and aimed to determine what effect LIF had on these cultures and whether they still had the ability to generate neurospheres. Methods Retinal cell suspensions were derived from adult human post-mortem tissue with ethical approval. With magnetic automated cell sorting (MACS CD133+ retinal cells were enriched from post mortem adult human retina. CD133+ retinal cell phenotype was analysed by flow cytometry and cultured cells were observed for proliferative capacity, neuropshere generation and differentiation with or without LIF supplementation. Results We demonstrated purification (to 95% of CD133+ cells from adult human postmortem retina. Proliferating cells were identified through BrdU incorporation and expression of the proliferation markers Ki67 and Cyclin D1. CD133+ retinal cells differentiated whilst forming neurospheres containing appropriate lineage markers including glia, neurons and photoreceptors. LIF maintained CD133+ retinal cells in a proliferative and relatively undifferentiated state (Ki67, Cyclin D1 expression without significant neurosphere generation. Differentiation whilst forming neurospheres was re-established on LIF withdrawal. Conclusion These data support the evidence that CD133 expression characterises a population of cells within the resident adult human retina which have progenitor cell properties and that their turnover and differentiation is influenced by LIF. This may explain differences in retinal responses observed following disease or injury.

  15. Synthesis and thermoluminescent characterization of LiF doped with Ag; Sintesis y caracterizacion termoluminiscente de LiF dopado con Ag

    Energy Technology Data Exchange (ETDEWEB)

    Encarnacion, E. K.; Reyes, J.; Guerrero, Z. [Universidad Autonoma de Santo Domingo, Facultad de Ciencias, Ciudad Universitaria, Santo Domingo (Dominican Republic); Sosa, M. A.; Vallejo, M. A.; Rivera P, E., E-mail: emma.kee@gmail.com [Universidad de Guanajuato, Campus Leon, Division de Ciencias e Ingenierias, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: In this paper the synthesis and characterization of lithium fluoride (LiF) crystals pure and activated with silver (Ag) is reported. The synthesis was carried out by the method of co-precipitation; three samples were obtained one of pure LiF and two were activated with 0.02 and 0.04% of Ag. All samples were subjected to X-ray emission and the results were analyzed. The synthesized samples were characterized by X-ray diffraction, thermoluminescence and X-ray fluorescence. The XRD results show complete crystal structures. The radiation dosimetry responses are discussed. These are the first results of a research conducted at the Universidad Autonoma de Santo Domingo in collaboration with the Universidad de Guanajuato. (Author)

  16. Density and ionic structure of NdF_3-LiF melts

    Institute of Scientific and Technical Information of China (English)

    胡宪伟; 王兆文; 高炳亮; 石忠宁; 刘风国; 曹晓舟

    2010-01-01

    NdF3-LiF melts are commonly used in the electrolysis process of metallic neodymium production. Research on the density and ionic structure of the electrolyte is important for its close connection with the electrolysis mechanism and process. In this paper, the density of LiF-NdF3 melts was studied by the Archimedes method. The results showed that the density decreased with increasing temperature and LiF contents. The changing law was discussed and explained in terms of the micro ionic structure of the melts....

  17. Dosimetric analysis for photon and electron beams in Whole body irradiation; Analisis dosimetrico para haces de fotones y electrones en irradiacion corporal total

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado G, M. [Posgrado. Fisica Medica Radiologica. Universidad Nacional de Colombia, Bogota. Instituto Nacional de Cancerologia. Instituto Regional de Cancer de la Orinoquia. Hospital Regional de Villavicencio, Meta (Colombia)

    1998-12-31

    To initiate the Whole body irradiation as an alternative for the treatment of the hematological diseases, leukemia and assistant for the osseous marrow transplantation, it may be taken account the application of International Protocols about control and quality assurance. It is established the intercomparison by the different dosimetric methods: cylindrical ionization chambers and parallel plane, radiographic emulsion film, semiconductor diodes (Mosfet transistors) and TLD-100 thermoluminescent crystals, obtained measurements for 140 x 140 cm{sup 2} fields and large distances 340 cm respect conventional fields in Radiotherapy. The in vitro dosimetry was realized at the Universal Anthropomorphic puppet Alderson Rando basically with the cylindrical crystals (1 mm diameter) of TLD-100 lithium fluoride. It was obtained the dose value with a 0.6 cm{sup 3} cylindrical ionization chamber and the Farmer electrometer for Whole body irradiation (ICT) with photons for electrons and were obtained values with the Markus plane parallel camera. Knowing the dose rate value to the source-surface distance DFS= 80 cm, it was calibrated the crystals with the reference radiation beam of {sup 60} Co for obtaining the response curve: Dose vs. Tl lecture. It was characterized the 10 % of the total population for 300 crystals for applying the statistics corresponding. The luminescence curve obtained of Gaussian form was considered satisfactory by its stability during the pre-anneal lecture and anneal process, getting the main peak lecture at 300 Centigrade according to assigned parameters at lecture equipment TLD Harshaw model 4500. The results indicate the functional dependence with the distance DFS= 340 cm for the following depth PPD, the relations TMR and TPR, the TAR is not calculated by the increment of the dispersion in air. The penumbra increment indicates an increase of the radiation field respect of luminous field. The dispersion angle q{sub 1} respect at the field central axis

  18. Irradiation dose determination below room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Bernal, S. E-mail: ramos@nuclecu.unam.mx; Cruz, E.; Negron-Mendoza, A.; Bustos, E

    2002-03-01

    The measurements presented were undertaken to provide quantitative information on the low temperature irradiation of thermoluminiscence phosphors. The crystals used were (a) LiF co-doped with Mg, Cu and P, and (b) CaSO{sub 4} doped with Dy. The absorbed dose values in the interval studied showed a linear behavior at low doses and low temperature. The aim of this work is to test if these crystals can be used to measure the dose absorbed by solids at low temperature.

  19. Control of flowering and cell fate by LIF2, an RNA binding partner of the polycomb complex component LHP1.

    Directory of Open Access Journals (Sweden)

    David Latrasse

    Full Text Available Polycomb Repressive Complexes (PRC modulate the epigenetic status of key cell fate and developmental regulators in eukaryotes. The chromo domain protein like heterochromatin protein1 (LHP1 is a subunit of a plant PRC1-like complex in Arabidopsis thaliana and recognizes histone H3 lysine 27 trimethylation, a silencing epigenetic mark deposited by the PRC2 complex. We have identified and studied an LHP1-Interacting Factor2 (LIF2. LIF2 protein has RNA recognition motifs and belongs to the large hnRNP protein family, which is involved in RNA processing. LIF2 interacts in vivo, in the cell nucleus, with the LHP1 chromo shadow domain. Expression of LIF2 was detected predominantly in vascular and meristematic tissues. Loss-of-function of LIF2 modifies flowering time, floral developmental homeostasis and gynoecium growth determination. lif2 ovaries have indeterminate growth and produce ectopic inflorescences with severely affected flowers showing proliferation of ectopic stigmatic papillae and ovules in short-day conditions. To look at how LIF2 acts relative to LHP1, we conducted transcriptome analyses in lif2 and lhp1 and identified a common set of deregulated genes, which showed significant enrichment in stress-response genes. By comparing expression of LHP1 targets in lif2, lhp1 and lif2 lhp1 mutants we showed that LIF2 can either antagonize or act with LHP1. Interestingly, repression of the FLC floral transcriptional regulator in lif2 mutant is accompanied by an increase in H3K27 trimethylation at the locus, without any change in LHP1 binding, suggesting that LHP1 is targeted independently from LIF2 and that LHP1 binding does not strictly correlate with gene expression. LIF2, involved in cell identity and cell fate decision, may modulate the activity of LHP1 at specific loci, during specific developmental windows or in response to environmental cues that control cell fate determination. These results highlight a novel link between plant RNA

  20. Lifetime Improvement of Organic Light Emitting Diodes using LiF Thin Film and UV Glue Encapsulation

    Science.gov (United States)

    Huang, Jian-Ji; Su, Yan-Kuin; Chang, Ming-Hua; Hsieh, Tsung-Eong; Huang, Bohr-Ran; Wang, Shun-Hsi; Chen, Wen-Ray; Tsai, Yu-Sheng; Hsieh, Huai-En; Liu, Mark O.; Juang, Fuh-Shyang

    2008-07-01

    This work demonstrates the use of lithium fluoride (LiF) as a passivation layer and a newly developed UV glue for encapsulation on the LiF passivation layer to enhance the stability of organic light-emitting devices (OLEDs). Devices with double protective layers showed a 25-fold increase in operational lifetime compared to those without any packaging layers. LiF has a low melting point and insulating characteristics and it can be adapted as both a protective layer and pre-encapsulation film. The newly developed UV glue has a fast curing time of only 6 s and can be directly spin-coated onto the surface of the LiF passivation layer. The LiF thin film plus spin-coated UV glue is a simple packaging method that reduces the fabrication costs of OLEDs.

  1. Monte Carlo calculations of monoenergetic electron depth dose distributions in LiF chips: Skin dose correction factors for beta rays

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Y.S. [Ben Gurion Univ. of the Negev, Beersheva (Israel); Hirning, C.R. [Ontario Hydro, Whitby (Canada); Yuen, P.; Wong, P. [Chalk River Labs., Ontario (Canada)

    1994-10-01

    Monte Carlo calculations have been carried out for monoenergetic electrons from 0.1 to 4 MeV irradiating LiF chips in both perpendicular and isotropic geometry. This enabled the calculation of skin dose correction factors (beta factors) for typical beta energy spectra as measured with a beta-ray spectrometer at CANDU nuclear generating stations. The correction factors were estimated by averaging the depth dose distributions for the monoenergetic electrons over the experimentally measured beta-ray spectra. The calculations illustrate the large uncertainty in beta factors arising from the unknown angular distribution of the beta-ray radiation field and uncertainties in the shape of the beta-ray spectra below 500 keV. 28 refs., 8 figs., 2 tabs.

  2. Directional effect on coloration in LiF crystal by H{sup +} and H{sub 2}{sup +} ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Gan Mingle; Naramoto, Hiroshi; Aoki, Yasushi; Yamamoto, Shunya; Zeng Jianer; Takeshita, Hidefumi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    In the present paper, the first results are reported about the coloration in LiF crystals induced by bombardments of single hydrogen ions (H{sup +}) and molecular hydrogen ions (H{sub 2}{sup +}) with the same velocity under the <100> aligned and random conditions. For the single hydrogen ion irradiation, the coloration is rather simple. The F-type color center absorption under the <100> aligned condition becomes larger than that under the random condition with the dose increase because of larger fraction of electronic energy loss under channeling condition. On the contrary, the coloration for the molecular ions does not show big channeling effect. In the low dose region some difference can be seen but the difference of coloration is not observed any more with the dose increase. The pronounced coloration for molecular ions under the channeling condition is observed in comparison with that for single ions. (author)

  3. Variation in the calibrated response of LiF, Al2O3, and silicon dosimeters when used for in-phantom measurements of source photons with energies between 30 KeV AND 300 KeV.

    Science.gov (United States)

    Poudel, Sashi; Currier, Blake; Medich, David C

    2015-04-01

    The MCNP5 radiation transport code was used to quantify changes in the absorbed dose conversion factor for LiF, Al2O3, and silicon-based electronic dosimeters calibrated in-air using standard techniques and summarily used to measure absorbed dose to water when placed in a water phantom. A mono-energetic photon source was modeled at energies between 30 keV and 300 keV for a point-source placed at the center of a water phantom, a point-source placed at the surface of the phantom, and for a 10-cm radial field geometry. Dosimetric calculations were obtained for water, LiF, Al2O3, and silicon at depths of 0.2 cm and 10 cm from the source. These results were achieved using the MCNP5 *FMESH photon energy-fluence tally, which was coupled with the appropriate DE/DF card for each dosimetric material studied to convert energy-fluence into the absorbed dose. The dosimeter's absorbed dose conversion factor was calculated as a ratio of the absorbed dose to water to that of the dosimeter measured at a specified phantom depth. The dosimeter's calibration value also was obtained. Based on these results, the absorbed dose conversion factor for a LiF dosimeter was found to deviate from its calibration value by up to 9%, an Al2O3 dosimeter by 43%, and a silicon dosimeter by 61%. These data therefore can be used to obtain LiF, Al2O3, and silicon dosimeter correction factors for mono-energetic and poly-energetic sources at measurement depths up to 10 cm under the irradiation geometries investigated herein.

  4. Effect of Bushenantai Recipe on the Expression of Endometrial LIF in Mice with Embryonic Implantation Dysfunction

    Institute of Scientific and Technical Information of China (English)

    Mingmin ZHANG; Yuqin HUANG; Guijin ZHU; Guangying HUANG; Liping DONG; Jinjin ZHANG

    2008-01-01

    In order to observe the effect of Bushenantai recipe on the expression of endometrial leukemia-inhibitory factor (LIF) in mice with embryonic implantation dysfunction (EID), 120 Kun- ruing mice post coition were randomized into three groups: normal control group, model group and traditional Chinese medicine group (TCM group) (n=40 in each group). Uterus was collected on the pregnancy day (Pd) 4, 5, 6 after an intravenous injection of Evan's blue. The endometrium was dyed by Evan's blue and the mean points of response were observed on Pd 5. The expression of LIF mRNA and protein was detected by RT-PCR and immunohistochemistry respectively and analyzed statistically by image system. The results showed that the number of implantation sites in model group was remarkably less than in normal control group and TCM group. There was no significant difference between normal control group and TCM group. The expression of L1F mRNA and protein in model group was delayed. Bushenantai recipe could increase the expression of LIF mRNA and protein in endometria of mice with EID. It was suggested that Bushenantai recipe could improve em- bryo implantation of mice with EID by promoting the endometrial LIF expression and endometrial decidualization.

  5. AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion

    Directory of Open Access Journals (Sweden)

    Rapp SM

    2011-08-01

    Full Text Available Steven M Rapp1, Larry E Miller2,3, Jon E Block31Michigan Spine Institute, Waterford, MI, USA; 2Miller Scientific Consulting Inc, Biltmore Lake, NC, USA; 3Jon E. Block, Ph.D., Inc., San Francisco, CA, USAAbstract: Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF system is a minimally invasive fusion device that accesses the lumbar (L4–S1 intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date.Keywords: AxiaLIF, fusion, lumbar, minimally invasive, presacral

  6. Deposition of LiF onto Films of Fullerene Derivatives Leads to Bulk Doping

    NARCIS (Netherlands)

    Torabi, Solmaz; Liu, Jian; Gordiichuk, Pavlo; Herrmann, Andreas; Qiu, Li; Jahani, Fatemeh; Hummelen, Jan C.; Koster, L. Jan Anton

    2016-01-01

    One of the most commonly used cathode interlayers for increasing the efficiency of electron injection/extraction in organic electronic devices is an ultrathin layer of LiF. Our capacitance measurements and electrical conductivity E analysis show that thin films of fullerene derivatives and their mix

  7. LIF and TNF alpha concentrations in embryo culture media are predictive for embryo implantation in IVF

    Institute of Scientific and Technical Information of China (English)

    Ursula Zollner; Sonja Bischofs; Irena Lalic; Klaus-Peter Zollner

    2012-01-01

    Objective:There is strong evidence that the cytokines leucemia inhibitory factor (LIF) and tumor necrosis factor (TNF) alpha are related to embryo development and implantation. The aim of this study was to determine the levels of LIF and TNF alpha in embryo culture media and to assess its relationship to the outcome of in-vitro fertilization and embryo transfer. Methods:A total of 99 patients were included in this prospective trial and underwent either IVF or ICSI procedure. A total of 865 oocytes were collected. Embryos were cultured in sequential media until day 5. A standardized morphology evaluation of all embryos, including a detailed pronuclear scoring, was performed daily during this period followed by the replacement of one or two selected embryos. Collected embryo culture fluids of days 3 and 5 were analysed for LIF and TNF alpha on days 3 and 5. Results:Mean TNF alpha concentration in culture media on day 3 was 0.54 and 0.37 pg/mL on day 5 and was significantly lower in women conceiving than in not conceiving (0.43 pg/mL versus 0.59 pg/mL on day 3). Mean LIF concentration on day 3 was 31.5 pg/mL and 35.5 pg/mL on day 5 and was significantly higher in women conceiving (56.2 pg/mL versus 22.2 pg/mL on day 3). Conclusions:The results indicate that LIF could have a function in early embryogenesis and as a factor required for embryo implantation. High TNF alpha concentrations seem to be predictive of implantation failure.

  8. Dosimetric verification of dose calculation algorithm in the lung during total marrow irradiation using helical tomotherapy.

    Science.gov (United States)

    Konstanty, Ewelina; Malicki, Julian; Łagodowska, Katarzyna; Kowalik, Anna

    2017-01-01

    Treatment of proliferative diseases of the hematopoietic system involves, in most cases, chemotherapy combined with radiation therapy, which is intended to provide adequate immunosuppressant. Conventionally, total body irradiation (TBI) was used; however, total marrow irradiation (TMI) performed with helical tomotherapy (HT) has been proposed as an alternative, with the aim of delivering the highest dose in the target area (skeleton bone). The purpose of this study is to evaluate the accuracy of the dose calculation algorithm for the lung in TMI delivered with HT. Thermoluminescent detectors (TLD-100 Harshaw) were used to measure delivered doses. Doses were calculated for 95 selected points in the central lung (53 TLDs) and near the rib bones (42 TLDs) in the anthropomorphic phantom. A total of 12 Gy were delivered (6 fractions of 2 Gy/fraction). HT-TMI technique reduces the dose delivered to the lungs in a phantom model to levels that are much lower than those reported for TBI delivered by a conventional linear accelerator. The mean calculated lung dose was 5.6 Gy versus a mean measured dose of 5.7 ± 2.4 Gy. The maximum and minimum measured doses were, respectively, 11.3 Gy (chest wall) and 2.8 Gy (central lung). At most of the 95 points, the measured dose was lower than the calculated dose, with the largest differences observed in the region located between the target volume and the adjacent lung tissue. The mean measured dose was lower than the calculated dose in both primary locations: -3.7% in the 42 rib-adjacent detectors and -3.0% in the 53 central lung TLDs. Our study has shown that the measured doses may be lower than those calculated by the HT-TMI calculation algorithm. Although these differences between calculated and measured doses are not clinically relevant, this finding merits further investigation.

  9. Soft x-ray free-electron laser imaging by LiF crystal and film detectors over a wide range of fluences.

    Science.gov (United States)

    Pikuz, Tatiana A; Faenov, Anatoly Ya; Fukuda, Yuji; Kando, Masaki; Bolton, Paul; Mitrofanov, Alexander; Vinogradov, Alexander V; Nagasono, Mitsuru; Ohashi, Haruhiko; Yabashi, Makina; Tono, Kensuke; Senba, Yasunori; Togashi, Tadashi; Ishikawa, Tetsuya

    2013-01-20

    LiF crystal and film detectors were used to measure the far-field fluence profile of a self-amplified spontaneous-emission free-electron laser beam and diffraction imaging with high spatial resolution. In these measurements the photoluminescence (PL) response of LiF crystal and film was compared over a wide range of soft x-ray fluences. It was found that the soft x-ray fluence dependences of LiF crystal and film differ. At low fluence, the LiF crystal shows higher PL response compared to LiF film, while this comparison is the opposite at higher fluence. Accurate measurement of LiF crystal and film PL response is important for precise characterization of the spatial, spectral, and coherence features of x-ray beams across the full profile and in localized areas. For such measurements, crucial LiF detector attributes are high spatial resolution and high dynamic range.

  10. A simple method for production and purification of soluble and biologically active recombinant human leukemia inhibitory factor (hLIF) fusion protein in Escherichia coli.

    Science.gov (United States)

    Imsoonthornruksa, Sumeth; Noisa, Parinya; Parnpai, Rangsun; Ketudat-Cairns, Mariena

    2011-02-20

    Mouse embryonic stem cells (mESCs) rely on a cytokine named leukemia inhibitory factor (LIF) to maintain their undifferentiated state and pluripotency. However, the progress of mESC research is restricted and limited to highly funded laboratories due to the cost of commercial LIF. Here we presented the homemade hLIF which is biologically active. The hLIF cDNA was cloned into two different vectors in order to produce N-terminal His₆-tag and Trx-His₆-tag hLIF fusion proteins in Origami(DE3) Escherichia coli. The His₆-hLIF fusion protein was not as soluble as the Trx-His₆-hLIF fusion protein. One-step immobilized metal affinity chromatography (IMAC) was done to recover high purity (> 95% pure) His₆-hLIF and Trx-His₆-hLIF fusion proteins with the yields of 100 and 200 mg/l of cell culture, respectively. The hLIF fusion proteins were identified by Western blot and verified by mass spectrometry (LC/MS/MS). The hLIF fusion proteins specifically promote the proliferation of TF-1 cells in a dose-dependent manner. They also demonstrate the potency to retain the morphology of undifferentiated mESCs, in that they were positive for mESC markers (Oct-4, Sox-2, Nanog, SSEA-1 and alkaline phosphatase activity). These results demonstrated that the N-terminal fusion tags of the His₆-hLIF and Trx-His₆-hLIF fusion proteins do not interfere with their biological activity. This expression and purification approach to produce recombinant hLIF is a simple, reliable, cost effective and user-friendly method.

  11. Study of energetic dependence of LiF TLDs for photons

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, Tassio A.; Antunes, Paula C.G.; Paiva, Fabio; Branco, Isabela S.; Sena, Michelle K.S.; Siqueira, Paulo T.D.; Yoriyaz, Helio, E-mail: tcavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The LiF TLDs are widely used for photon dosimetry. However, in the most case the energetic dependence of these TLDs are not taken into account. This work is a preliminary study of energetic photon dependence in LiF TLD (TLD 700, enriched with {sup 7}Li). For this study it was utilized a methodology already used in others works that seek understand the dependence energetic of TLD. It was utilized three different X-ray spectrum and a {sup 137}Cs source; Beyond the calculus utilized in previous works, it was built the calibration curve for each spectrum to see the difference in dosimetry that the energetic dependence could cause. (author)

  12. Laboratory LiF characterization of different phytoplankton species originating harmful blooms

    Energy Technology Data Exchange (ETDEWEB)

    Barbini, R.; Colao, F.; Fantoni, R.; Palucci, A.; Ribezzo, S. [ENEA, Centro Ricerche Frascati, Rome (Italy). Dip. Innovazione; Micheli, C. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione

    1997-11-01

    A systematic laboratory characterization of different phytoplankton cultures has been performed in combination with LiF (Laser Induced Fluorescence) measurements aimed to investigate the possibility of their remote monitoring by means of lidar fluoro sensor systems. Cultures of microalgae characterized by different pigment contents have been analyzed in the visible region upon UV laser excitation. High resolution laboratory spectra have been measured in order to obtain the fingerprint of each species. Emission wavelength related to the main pigments contribution have been identified. Detection limits of the emitted red chlorophyll signal have been evaluated for the different species after dilution in the culture medium and in real sea water. Prior to the LiF excitation aimed to the remote characterization the algal cultures were morphologically analyzed by fluorescence and scanning electron microscopy. Furthermore the relevant cell number was counted for biomass estimation, and the chlorophylls content was determined by different chemical methods.

  13. PIV and LIF study of slot continuous jet at low Reynolds number

    Directory of Open Access Journals (Sweden)

    Broučková Zuzana

    2016-01-01

    Full Text Available This study deals with a continuous jet issuing from a small narrow slot with a width of 0.36 mm. The experimental arrangement is based on the piezoelectric synthetic jet actuator studied previously for easy comparisons. The working fluid is water at room temperature. The experiments were performed using methods of particle image velocimetry (PIV and flow visualization (laser induced fluorescence, LIF. The time-mean volume flux through the exit nozzle was quantified using precise scales. The mean velocity and the Reynolds number were evaluated as Um = 0.12 m/s and Re = 90, respectively. The results of LIF and PIV techniques revealed the three-dimensional character of the flow field, namely the saddle-shape velocity profiles. This behavior is typical for steady jets from a rectangular nozzle. The obtained results were compared with previous measurements of the synthetic jet issuing from the same cavity and the slot nozzle.

  14. Thermal neutron detection by entrapping 6LiF nanocrystals in siloxane scintillators

    Science.gov (United States)

    Carturan, S. M.; Marchi, T.; Maggioni, G.; Gramegna, F.; Degerlier, M.; Cinausero, M.; Dalla Palma, M.; Quaranta, A.

    2015-06-01

    Exploiting the long experience in design and production of scintillating mixtures based on siloxane matrices with combinations of primary dye and waveshifter, a first set of 6LiF loaded scintillator disks has been produced. The synthesis is herein described and reported, as well as preliminary results on their light response towards thermal neutrons. The preservation of transparency and mechanical integrity of the scintillator material is challenging when introducing the inorganic salt LiF which is a "foreign body" to the organic polysiloxane host matrix Different strategies such as synthesis of nanoparticles and surface functionalization have been pursued to succeed in the entrapment of the neutron converter whilst maintaining moderate light output, optical transparency and flexibility of the base scintillator.

  15. STAT5 transcriptional activity is impaired by LIF in a mammary epithelial cell line.

    Science.gov (United States)

    Granillo, Agustina Rodriguez; Boffi, Juan Carlos; Barañao, Lino; Kordon, Edith; Pecci, Adali; Guberman, Alejandra

    2007-05-11

    Gene regulation mediated by STAT factors has been implicated in cellular functions with relevance to a variety of processes. Particularly, STAT5 and STAT3 play a crucial role in mammary epithelium displaying reciprocal activation kinetics during pregnancy, lactation and involution. Here, we show that LIF treatment of mammary epithelial HC11 cells reduces the phosphorylation levels and transcriptional activity of p-STAT5 in correlation with STAT3 phosphorylation. We have also found that STAT5 activity is negatively modulated by this cytokine, both on a gene whose expression is induced, as well as on a promoter repressed by STAT5. Besides, our results show that lactogenic hormones increase LIF effect on gene induction without modifying STAT3 phosphorylation state. Our findings strongly suggest that there is crosstalk between STAT5 and STAT3 pathways that could modulate their ability to regulate gene expression.

  16. IMPROVEMENT IN PREPARATION OF LiF TLD AND OPTIMIZATION OF MEASUREMENT PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    张建; 郭勇; 等

    1994-01-01

    The technological process for preparation of LiF TLD is reported.Sixteen types of TLD of LiF:Mg,Ti and LiF:Mg,Cu,P series are produced for dosimetry of X,γ radiations and in neutron-γ mixed radiation field.The measurement parameters have been optimizationally selected by factors of parameter evaluation(P) and orthogonal method,and the procedure of quality control is recommended.

  17. Investigating the laser heating of underdense plasmas at conditions relevant to MagLIF

    Science.gov (United States)

    Harvey-Thompson, Adam

    2015-11-01

    The magnetized Liner Inertial Fusion (MagLIF) scheme has achieved thermonuclear fusion yields on Sandia's Z Facility by imploding a cylindrical liner filled with D2 fuel that is preheated with a multi-kJ laser and pre-magnetized with an axial field Bz = 10 T. The challenge of fuel preheating in MagLIF is to deposit several kJ's of energy into an underdense (ne/ncritMagLIF. In particular, magnetization of the preheated plasma suppresses electron thermal conduction, which can modify laser energy coupling. Providing an experimental dataset in this regime is essential to not only understand the dynamics of a MagLIF implosion and stagnation, but also to validate magnetized transport models and better understand the physics of laser propagation in magnetized plasmas. In this talk, we present data and analysis of several experiments conducted at OMEGA-EP and at Z to investigate laser propagation and plasma heating in underdense D2 plasmas under a range of conditions, including densities (ne = 0.05-0.1 nc) and magnetization parmaters (ωceτe ~ 0-10). The results show differences in the electron temperature of the heated plasma and the velocity of the laser burn wave with and without an applied magnetic field. We will show comparisons of these experimental results to 2D and 3D HYDRA simulations, which show that the effect of the magnetic field on the electron thermal conduction needs to be taken into account when modeling laser preheat. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  18. On the localization of plastic strain under compression of LiF crystals

    Science.gov (United States)

    Barannikova, S. A.; Nadezhkin, M. V.; Zuev, L. B.

    2010-07-01

    The plastic flow localization patterns for alkali halide LiF crystals under compression have been investigated. The main spatiotemporal regularities of the strain localization at different stages of deformation hardening in the single crystals have been established. The relation has been traced between the orientation of localized strain zones and the crystallography of slip systems of the test specimens studied simultaneously by the double-exposure speckle photography and photoelasticity methods.

  19. Investigation of Three-Dimensional Flow Structure in a Transonic Diffuser by the LIF Method

    OpenAIRE

    小野, 大輔; 半田, 太郎; 青木, 俊之; 益田, 光治

    2007-01-01

    The three-dimensional flow structure induced by normal shock-wave/boundary-layer interaction in a transonic diffuser is investigated by a laser-induced fluorescence (LIF) method. This diagnostic system uses an argon-ion laser as a light source, and target gas is dry nitrogen with iodine seeded as a fluorescence material. The Mach-number distributions in the diffuser are obtained from the measured fluorescence intensity, and the three-dimensional shape of the boundary layers is obtained immedi...

  20. Aberrant expression of leukemia inhibitory factor receptor (LIFR) and leukemia inhibitory factor (LIF) is associated with tubal pregnancy occurrence

    OpenAIRE

    Li, Yong; Sun, Lizhou; ZHAO, Denmei; Ouyang, Jun; Xiang, Mei

    2015-01-01

    Tubal pregnancy is a major cause of maternal death in the first trimester and exploration of its underlying molecular mechanism is of great importance. This study aimed to explore the association of tubal pregnancy with leukemia inhibitory factor (LIF) and leukemia inhibitory factor receptor (LIFR) expression in oviduct tissues. Materials and methods: Immunohistochemistry was performed to probe the differential expression of LIF and LIFR in oviduct tissues among a control group (including NP...

  1. Chiral MEKC-LIF of amino acids in foods: analysis of vinegars.

    Science.gov (United States)

    Carlavilla, Davinia; Moreno-Arribas, M Victoria; Fanali, Salvatore; Cifuentes, Alejandro

    2006-07-01

    The formation of D-amino acids (D-aa's) in many fermented foods depends, among other factors, on the particular fermentation conditions, the action and autolysis of the microorganisms involved. In this sense, the analysis of chiral amino acids is an interesting analytical strategy for food scientists, since these compounds can be used as bacterial markers and can help, e.g., to detect adulterations, microbiological contaminations, etc. In this work, a fast and sensitive method based on MEKC-LIF has been developed to analyze and quantitate L-amino acid (L-aa) and D-aa in vinegars. The chiral MEKC-LIF procedure uses 100 mM sodium tetraborate, 30 mM SDS, and 20 mM beta-CD at pH 9.7 as running buffer, obtaining a good separation of the main vinegar L-/D-aa previously derivatized with fluorescein isothiocianate. Namely, L/D proline, alanine, arginine, glutamic, and aspartic acid, plus the nonchiral amino acid gamma-aminobutyric acid are separated in less than 20 min with high efficiency (up to 720,000 plates/m) and good sensitivity (LODs lower than 16.6 nM were achieved). Several D-aa's were detected and quantified in balsamic, sherry, white wine, and cider vinegars using this MEKC-LIF procedure, observing interesting differences in their L-aa and D-aa profiles and contents.

  2. Application of tridimensional intravertebral bone graft combined with AxiaLIF technique in lumbar interbody fusion

    Directory of Open Access Journals (Sweden)

    Xiangdong Duan

    2009-05-01

    Full Text Available "nLumbar interbody fusion techniques are becoming more and more minimally invasive. AxiaLIF technique can be used in low back pain caused by degenerative disc disease or minor spondylolisthesis, but there are risks for fusion failure. Intravertebral bone graft is performed in painful osteoporotic or posttraumatic vertebral compression fractures (VCFs. Until now, no attempt has been made to apply intravertebral bone graft with AxiaLIF technique."nSo first, we hypothesize a novel method for tridimensional intravertebral bone graft with a special designed bone grafting instrument and describe it vividly. The special instrument would mainly consist of a hollow tube and a rod, the distal parts of them would be shape into 45o slope, so the direction of grafting would be decided by the slope. By rotating the tube we can deliver cancellous bone granules in one plane, but by retreating the tube we can perform tridimensional intravertebral bone graft. Second, intravertebral bone graft is supposed to be performed combined with AxiaLIF technique in order to create biologic vertebral reconstruction and raise fusion rate. We believe this is the first description of such a method, future clinical studies are needed to validate these hypotheses.

  3. The Effect of External Magnetic Fields on the MRT Instability in MagLIF

    Science.gov (United States)

    Hess, Mark; Peterson, Kyle; Weis, Matthew; Lau, Yue Ying

    2014-10-01

    Recent experiments on MagLIF which incorporate an external B-field suggest that the MRT instability within the liner has a different behavior than without the B-field. Previous work by Chandrasekhar and Harris have illustrated how the MRT growth rate, assuming fixed liner density and fixed acceleration, can change due to the presence of an external B-field. In this work, we show how the growth rate of the MRT instability is dynamically affected by the rapidly varying acceleration, liner density, and surface magnetic field, which is composed of the external B-field and the drive B-field of the liner in the MagLIF experiments. In addition, we also examine the effects of finite liner resistivity on MRT growth, which gives rise to an additional time scale corresponding to magnetic diffusion. We discuss the implications of this result for future MagLIF designs. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

  4. Leukemia Inhibitory Factor (LIF) Inhibition during Mid-Gestation Impairs Trophoblast Invasion and Spiral Artery Remodelling during Pregnancy in Mice.

    Science.gov (United States)

    Winship, Amy; Correia, Jeanne; Zhang, Jian-Guo; Nicola, Nicos A; Dimitriadis, Evdokia

    2015-01-01

    The placenta forms the interface between the maternal and fetal circulation and is critical for the establishment of a healthy pregnancy. Trophoblast cell proliferation, migration and invasion into the endometrium are fundamental events in the initiation of placentation. Leukemia inhibitory factor (LIF) has been shown to promote trophoblast invasion in vitro, however its precise role in trophoblast invasion in vivo is unknown. We hypothesized that LIF would be required for normal trophoblast invasion and spiral artery remodeling in mice. Both LIF and its receptor (LIFRα) co-localized with cytokeratin-positive invasive endovascular extravillous trophoblasts (EVT) in mouse implantation sites during mid-gestation. Temporally blocking LIF action during specific periods of placental development via administration of our unique LIFRα antagonist, PEGLA, resulted in abnormal trophoblast invasion and impaired spiral artery remodeling compared to PEG control. PEGLA-treated mouse decidual vessels were characterized by retention of α-smooth muscle actin (αSMA)-positive vascular smooth muscle cells (VSMCs), while PEG control decidual vessels were remodelled by cytokeratin-positive trophoblasts. LIF blockade did not alter F4/80-positive decidual macrophage numbers between treatment groups, but resulted in down-regulation of decidual transcript levels of monocyte chemoattractant protein-1 (MCP-1) and interleukin-10 (IL-10), which are important immune cell activation factors that promote spiral artery remodeling during pregnancy. Our data suggest that LIF plays an important role in trophoblast invasion in vivo and may facilitate trophoblast-decidual-immune cell cross talk to enable adequate spiral artery remodeling.

  5. Electronic sputtering of LiF, CaF2, LaF3 and UF4 with 197 MeV Au ions. Is the stoichiometry of atom emission preserved?

    Science.gov (United States)

    Toulemonde, M.; Assmann, W.; Muller, D.; Trautmann, C.

    2017-09-01

    Sputtering experiments with swift heavy ions in the electronic energy loss regime were performed by using the catcher technique in combination with elastic recoil detection analysis. Four different fluoride targets, LiF, CaF2, LaF3 and UF4 were irradiated in the electronic energy loss regime using 197 MeV Au ions. The angular distribution of particles sputtered from the surface of freshly cleaved LiF and CaF2 single crystals is composed of a broad cosine distribution superimposed by a jet-like peak that appears perpendicular to the surface independent of the angle of beam incidence. For LiF, the particle emission in the entire angular distribution (jet plus broad cosine component) is stoichiometric, whereas for CaF2 the ratio of the sputtered F to Ca particles is at large angles by a factor of two smaller than the stoichiometry of the crystal. For single crystalline LaF3 no jet component is observed and the angular distribution is non-stoichiometric with the number of sputtered F particles being slightly larger than the number of sputtered La particles. In the case of UF4, the target was polycrystalline and had a much rougher surface compared to cleaved crystals. This destroys the appearance of a possible jet component leading to a broad angular distribution. The ratio of sputtered U atoms compared to F atoms is in the order of 1-2, i.e. the number of collected particles on the catcher is also non-stoichiometric. Such unlike behavior of particles sputtered from different fluoride crystals creates new questions.

  6. Cloning of leukemia inhibitory factor (LIF) and its expression in the uterus during embryonic diapause and implantation in the mink (Mustela vison).

    Science.gov (United States)

    Song, J H; Houde, A; Murphy, B D

    1998-09-01

    Leukemia inhibitory factor (LIF) is essential for embryo implantation in mice. Whether LIF plays a role in termination of embryonic diapause and initiation of implantation in carnivores, especially in species with obligate delayed implantation such as the mink, is not known. The objectives of this study were to clone the LIF coding sequence in the mink and determine its mRNA abundance in the uterus through embryonic diapause, implantation, and early postimplantation. We show that the mink LIF cDNA contains 609 nt encoding a deduced protein of 203 amino acids. The homologies are 80.6, 90, 88.2, 87.6, and 86.8% in coding sequence and 79.2, 90.1, 91, 90.1 and 85.4% in amino acid sequence with mouse, human, pig, cow, and sheep respectively. Glycosylation sites and disulfide bonds present in other species are generally conserved in the mink LIF sequence. Quantitation by polymerase chain reaction amplification indicates that LIF mRNA is expressed in mink uterus just prior to implantation and during the first two days after implantation, but not during diapause or later after implantation pregnancy. The abundance of LIF mRNA was significantly higher in the uterus at the embryo expansion stage (P coincidence of LIF expression with implantation in this species suggests that LIF is involved in the implantation process, and may be a maternal signal which terminates obligate embryonic diapause.

  7. Improving efficiency of organic light-emitting devices by optimizing the LiF interlayer in the hole transport layer

    Institute of Scientific and Technical Information of China (English)

    Jiauo Zhi-Qiang; Wu Xiao-Ming; Hua Yu-Lin; Dong Mu-Sen; Su Yue-Ju; Shen Li-Ying; Yin Shou-Gen

    2011-01-01

    The efficiency of organic light-emitting devices (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-N,l' biphenyl-4,4'-diamine (NPB) (the hole transport layer) and tris(8-hydroxyquinoline) aluminum (Alq3) (both emission and electron transport layers) is improved remarkably by inserting a LiF interlayer into the hole transport layer.This thin LiF interlayer can effectively influence electrical performance and significantly improve the current efficiency of the device.A device with an optimum LiF layer thickness at the optimum position in NPB exhibits a maximum current efficiency of 5.96 cd/A at 215.79 mA/cm2,which is about 86% higher than that of an ordinary device (without a LiF interlayer,3.2 cd/A).An explanation can be put forward that LiF in the NPB layer can block holes and balance the recombination of holes and electrons.The results may provide some valuable references for improving OLED current efficiency.

  8. LiF Reduces MICs of Antibiotics against Clinical Isolates of Gram-Positive and Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    H. C. Syed

    2012-01-01

    Full Text Available Antibiotic resistance is an ever-growing problem yet the development of new antibiotics has slowed to a trickle, giving rise to the use of combination therapy to eradicate infections. The purpose of this study was to evaluate the combined inhibitory effect of lithium fluoride (LiF and commonly used antimicrobials on the growth of the following bacteria: Enterococcus faecalis, Staphyloccoccus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, and Streptococcus pneumoniae. The in vitro activities of ceftazidime, sulfamethoxazole-trimethoprim, streptomycin, erythromycin, amoxicillin, and ciprofloxacin, doxycycline, alone or combined with LiF were performed by microdilution method. MICs were determined visually following 18–20 h of incubation at 37°C. We observed reduced MICs of antibiotics associated with LiF ranging from two-fold to sixteen-fold. The strongest decreases of MICs observed were for streptomycin and erythromycin associated with LiF against Acinetobacter baumannii and Streptococcus pneumoniae. An eight-fold reduction was recorded for streptomycin against S. pneumoniae whereas an eight-fold and a sixteen-fold reduction were obtained for erythromycin against A. baumannii and S. pneumoniae. This suggests that LiF exhibits a synergistic effect with a wide range of antibiotics and is indicative of its potential as an adjuvant in antibiotic therapy.

  9. Estimates of crystalline LiF thermal conductivity at high temperature and pressure by a Green-Kubo method

    Science.gov (United States)

    Jones, R. E.; Ward, D. K.

    2016-07-01

    Given the unique optical properties of LiF, it is often used as an observation window in high-temperature and -pressure experiments; hence, estimates of its transmission properties are necessary to interpret observations. Since direct measurements of the thermal conductivity of LiF at the appropriate conditions are difficult, we resort to molecular simulation methods. Using an empirical potential validated against ab initio phonon density of states, we estimate the thermal conductivity of LiF at high temperatures (1000-4000 K) and pressures (100-400 GPa) with the Green-Kubo method. We also compare these estimates to those derived directly from ab initio data. To ascertain the correct phase of LiF at these extreme conditions, we calculate the (relative) phase stability of the B1 and B2 structures using a quasiharmonic ab initio model of the free energy. We also estimate the thermal conductivity of LiF in an uniaxial loading state that emulates initial stages of compression in high-stress ramp loading experiments and show the degree of anisotropy induced in the conductivity due to deformation.

  10. Distributed synaptic weights in a LIF neural network and learning rules

    Science.gov (United States)

    Perthame, Benoît; Salort, Delphine; Wainrib, Gilles

    2017-09-01

    Leaky integrate-and-fire (LIF) models are mean-field limits, with a large number of neurons, used to describe neural networks. We consider inhomogeneous networks structured by a connectivity parameter (strengths of the synaptic weights) with the effect of processing the input current with different intensities. We first study the properties of the network activity depending on the distribution of synaptic weights and in particular its discrimination capacity. Then, we consider simple learning rules and determine the synaptic weight distribution it generates. We outline the role of noise as a selection principle and the capacity to memorize a learned signal.

  11. Auto and crosscorrelograms for the spike response of LIF neurons with slow synapses

    CERN Document Server

    Moreno-Bote, Ruben

    2006-01-01

    An analytical description of the response properties of simple but realistic neuron models in the presence of noise is still lacking. We determine completely up to the second order the firing statistics of a single and a pair of leaky integrate-and-fire neurons (LIFs) receiving some common slowly filtered white noise. In particular, the auto- and cross-correlation functions of the output spike trains of pairs of cells are obtained from an improvement of the adiabatic approximation introduced in \\cite{Mor+04}. These two functions define the firing variability and firing synchronization between neurons, and are of much importance for understanding neuron communication.

  12. Point and planar LIF for velocity-concentration correlations in a jet in cross flow

    DEFF Research Database (Denmark)

    Meyer, Knud Erik; Özcan, Oktay; Larsen, Poul Scheel

    2002-01-01

    (LDA). The flow considered is the mixing of a jet in a fully developed cross flow in a square duct with a width of 10 jet diameters. Both a laminar flow case, Re=675, and a turbulent flow case, Re=33750, are presented . For both flows, the ratio jet-to-duct mean velocities was R=3.3. Result of mean...... velocities, mean concentration and Reynolds fluxes in the symmetry plane of the jet are presented for PIV and PLIF measurements. The LIF measurements performed with the LDA equipment was in general in good agreement with the PIV/PLIF measurements. The cross sections selected for comparison are challenging...

  13. Temperature and velocity fields in natural convection by PIV and LIF

    DEFF Research Database (Denmark)

    Meyer, Knud Erik; Larsen, Poul Scheel; Westergaard, C. H.

    2002-01-01

    Natural convection in a cubical cavity (L = 250 mm) filled with water is created by heating a square plate (0.5 L) centred in the bottom wall and by cooling the sidewalls, while the remaining walls are insulated. The Rayleigh number based on cavity side length and temperature difference between...... plate and cooled walls is 1.4×10^10. The flow is turbulent and is similar to some indoor room flows. Combined Particle Image Velocimetry (PIV) and Planar Light Induced Fluorescence (LIF) are used to measure local velocities and temperatures. Data measured in a symmetry plane parallel to a sidewall...

  14. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  15. Statistical differences and systematic effect on measurement procedure in thermoluminescent dosimetry of the Iodine-125 brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Zeituni, Carlos A.; Moura, Eduardo S.; Rostelato, Maria Elisa C.M.; Manzoli, Jose E.; Moura, Joao Augusto; Feher, Anselmo, E-mail: czeituni@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Karam, Dib [Universidade de Sao Paulo (USP Leste), Sao Paulo, SP (Brazil). Escola de Artes, Ciencias e Humanidades

    2009-07-01

    In order to provide the dosimetry for Iodine-125 seed production in Brazil, Harshaw thermoluminescent dosimeters (TLD-100) will be used. Even if measurements with TLD-100 of the same batch of fabrication are performed, the response will not be the same. As a consequence, they must be measured one by one. These dosimeters are LiF type with a micro-cube (1 mm x 1 mm x 1 mm) shape. Irradiations were performed using Iodine-125 seeds to guarantee the same absorbed dose of 5 Gy in each dosimeter. It has been used a Solid Water Phantom with three concentrically circle with 20 mm, 50 mm and 70 mm diameters. The angle of positions used was 0 deg, 30 deg, 60 deg and 90 deg. Of course there are 2 positions in 0 deg and 90 deg and 4 positions in 30 deg and 60 deg. These complete procedures were carried out five times in order to compare the data and minimize the systematic error. The iodine-125 seed used in the experiment was take off in each measure and put again turning his position 180 deg to guarantee the systematic error was minimized. This paper presents also a little discussion about the statistical difference in the measurement and the calculation procedure to determine the systematic error in these measurements. (author)

  16. Determination of absorbed dose in crystalline and thyroid gland with irradiation protocols applied in orthopantomography equipment for dental examination; Determinacion de dosis absorbida en cristalino y glandula tiroides con protocolos de irradiacion aplicados en equipos de ortopantomografia para panoramica dental

    Energy Technology Data Exchange (ETDEWEB)

    Munoz A, A. A.; Ramirez A, L. M. [Instituto Tecnologico Metropolitano, Grupo de Investigacion e Innovacion Biomedica, Medellin, Antioquia (Colombia); Sosa A, M. A.; Azorin V, J. C.; Vallejo H, M. A. [Universidad de Guanajuato, Departamento de Fisica, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2016-10-15

    Ionizing radiations are very useful in the medical field for the diagnostic use of different pathologies. Currently there are different technologies for diagnostic imaging using conventional X-ray, computed tomography, mammography, angiography, dental panoramic X-ray, among others. However, it should be noted that exposure to radiation in this type of diagnostic tests has increased considerably in recent years, because radiological examinations are not always carried out according to the actual clinical needs of each patient, increasing the risk to develop cancer. In this paper, the absorbed dose in the lens and thyroid gland was measured with the help of TLD-100 dosimeters located in a PMMA phantom adapted for orthopantomography (dental panoramic X-ray) equipment in 5 hospitals; using the parameters pre-configured for normal adult for irradiation. A Harshaw 3500 equipment was used to read the dosimeters, obtaining a value of 1.324 ± Sd 0.01 mGy for crystalline and 1.044 ± Sd 0.03 mGy values which are intended to be validated under other conditions and protocols. (Author)

  17. Meyve ve sebze lif konsantreleri ilavesinin hamurun reolojik özellikleri ve bisküvi kalitesine etkileri

    OpenAIRE

    2011-01-01

       Çalışmada; elma, kayısı, portakal, limon, greyfurt, havuç ve balkabağı gibi meyve ve sebzelerden elde edilen lif konsantreleri, iki farklı buğday çeşidinden elde edilen unlara (Gerek-79 ve Guadalupe), değişik oranlarda (% 0, 10, 15, 20 ve 25) katılarak  bunların hamur reolojik özellikleri ile bisküvi kalitesine etkileri araştırılmıştır.

       Araştırmada kullanılan lif konsantrelerinden sebze lif konsantrelerinin...

  18. Magnetic Field Measurements in NSTX-U with the MSE-LIF Diagnostic

    Science.gov (United States)

    Levinton, Fred; Foley, Jill; Dicicco, Darrell; Cylinder, David; La Fleur, Hannah; Yuh, Howard

    2014-10-01

    The motional Stark effect with laser-induced fluorescence diagnostic (MSE-LIF) was installed on NSTX during the 2011 run year. The MSE-LIF will enable radially resolved measurements of the magnetic field pitch angle and magnitude, both of which can be used to constrain plasma equilibrium reconstructions. A diagnostic neutral beam with low axial energy spread, low divergence, and high reliability has been developed. It operates routinely at 35 kV and 40 mA. A laser has been developed with high power (~10 W) and optimal linewidth matched to the energy spread of the neutral beam (~6 GHz). The laser wavelength is near 651 nm for a match to the Doppler-shifted Balmer-alpha transition in the beam neutrals. The unique high-power, moderate linewidth laser system utilizes a 19 emitter diode laser bar and feedback from a volume Bragg grating for line width narrowing. A magnetic shield protects the ion source from the NSTX stray fields. Initial data in a gas-filled torus and low magnetic fields was taken on NSTX. Several improvements have been made to the system during the NSTX upgrade, including adding more spatial channels and several laser improvements. Supported by USDOE Grant No. DE-FG02-01ER54616.

  19. LIF diagnostics of hydroxyl radical in a methanol containing atmospheric-pressure plasma jet

    Science.gov (United States)

    Qian, Mu-Yang; Liu, San-Qiu; Pei, Xue-Kai; Lu, Xin-Pei; Zhang, Jia-Liang; Wang, De-Zhen

    2016-10-01

    In this paper, a pulsed-dc CH3OH/Ar plasma jet generated at atmospheric pressure is studied by laser-induced fluorescence (LIF) and optical emission spectroscopy (OES). A gas-liquid bubbler system is proposed to introduce the methanol vapor into the argon gas, and the CH3OH/Ar volume ratio is kept constant at about 0.1%. Discharge occurs in a 6-mm needle-to-ring gap in an atmospheric-pressure CH3OH/Ar mixture. The space-resolved distributions of OH LIF inside and outside the nozzle exhibit distinctly different behaviors. And, different production mechanisms of OH radicals in the needle-to-ring discharge gap and afterglow of plasma jet are discussed. Besides, the optical emission lines of carbonaceous species, such as CH, CN, and C2 radicals, are identified in the CH3OH/Ar plasma jet. Finally, the influences of operating parameters (applied voltage magnitude, pulse frequency, pulsewidth) on the OH radical density are also presented and analyzed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11465013 and 11375041), the Natural Science Foundation of Jiangxi Province, China (Grant Nos. 20151BAB212012 and 20161BAB201013), and the International Science and Technology Cooperation Program of China (Grant No. 2015DFA61800).

  20. Ceramic thick film humidity sensor based on MgTiO{sub 3} + LiF

    Energy Technology Data Exchange (ETDEWEB)

    Kassas, Ahmad, E-mail: a.kassas.mcema@ul.edu.lb [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Bernard, Jérôme; Lelièvre, Céline; Besq, Anthony; Guhel, Yannick; Houivet, David; Boudart, Bertrand [Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Lakiss, Hassan [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Faculty of Engineering, Section III, Hariri Campus, Hadath, Beirut (Lebanon); Hamieh, Tayssir [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon)

    2013-10-15

    Graphical abstract: - Highlights: • The fabricated sensor based on MgTiO{sub 3} + LiF materials used the spin coating technology. • The response time is 70 s to detect variation between 5 and 95% relative humidity. • The addition of Scleroglucan controls the viscosity and decreases the roughness of thick film surface. • This humidity sensor is a promising, low-cost, high-quality, reliable ceramic films, that is highly sensitive to humidity. - Abstract: The feasibility of humidity sensor, consisting of a thick layer of MgTiO{sub 3}/LiF materials on alumina substrate, was studied. The thermal analysis TGA-DTGA and dilatometric analysis worked out to confirm the sintering temperature. An experimental plan was applied to describe the effects of different parameters in the development of the thick film sensor. Structural and microstructural characterizations of the developed thick film were made. Rheological study with different amounts of a thickener (scleroglucan “sclg”), showing the behavior variation, as a function of sclg weight % was illustrated and rapprochement with the results of thickness variation as a function of angular velocity applied in the spin coater. The electrical and dielectric measurements confirmed the sensitivity of the elaborated thick film against moisture, along with low response time.

  1. Effects of Magnetic Field Topology on Secondary Neutron Spectra in MagLIF

    Science.gov (United States)

    Appelbe, Brian; Chittenden, Jeremy

    2015-11-01

    Ignition in Magneto-Inertial Fusion schemes requires both inertial and magnetic confinement of the fuel and charged fusion products. Recent theoretical and experimental work has demonstrated the confinement of charged fusion products by magnetic fields in Magnetized Liner Inertial Fusion (MagLIF) experiments. This confinement can be inferred from the ratio of secondary to primary neutron yields and the shape of secondary neutron spectra. In this work we investigate the effects of magnetic field topology on the shape of secondary neutron spectra. The MagLIF design has a cylindrical geometry and includes both axial and azimuthal magnetic fields. The azimuthal field is initially in the liner surrounding the fuel but instability growth may cause it to penetrate into the fuel. Charged fusion products (such as tritons or alpha particles) that are isotropically emitted and then confined by an axial field will flow parallel and anti-parallel to the field with equal intensities. In the case of tritons, this motion results in a secondary neutron spectrum emitted in the axial direction that is symmetric. However, in an azimuthal field such particles exhibit singular orbits and there is a net ion drift along the axis. This ion drift can cause the secondary neutron spectrum to be asymmetric. We examine the effects on the spectrum shape of confinement by a combination of axial and azimuthal fields.

  2. VISAR Unfold Analysis of MagLIF Laser Blast Wave Experiments

    Science.gov (United States)

    Hess, Mark; Peterson, Kyle; Harvey-Thompson, Adam

    2015-06-01

    MagLIF (Magnetized Liner Inertial Fusion) is a fusion energy scheme, which utilizes a short laser pulse to preheat a fuel, and a magnetically driven cylindrical liner to compress the fuel to high energy density plasma conditions. Recently, a set of successful experiments have been performed to evaluate the effectiveness of our preheat process in MagLIF using the Z-Beamlet laser at Sandia. The fuel is preheated in the liner, with no compression from the Z-machine, and a VISAR diagnostic was fielded on the outer surface of the liner to measure velocity of the liner due to the pressure of the laser blast wave on the inner surface of the liner. In support of this program, we developed a fast unfold method of the VISAR data using semi-analytical techniques/numerical methods. The method incorporates appropriate boundary conditions at both edges of the VISAR foil, realistic EOS tables, and an additional pressure pulse time-delay feature for accurately unfolding the time-dependent pressure from the VISAR data. Our fully automated method can produce high-quality unfolds of the laser blast wave in under a minute. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.

  3. VISAR Unfold Analysis of Load Current in MagLIF Experiments

    Science.gov (United States)

    Hess, Mark; McBride, Ryan; Martin, Matthew

    2013-10-01

    An accurate prediction of the load current is essential in the performance of MagLIF experiments on the Z-Machine at Sandia. At present, the most accurate diagnostic for measuring load current on the Z-machine is the well-established VISAR technique. The VISAR diagnostic measures the velocity of a thin aluminum foil placed near the load, which is subject to the magnetic pressure produced by the load current, using a laser interferometer. The load current unfold analysis is highly nonlinear due to the equation of state/conductivity models, along with the MHD equations governing the foil. Nevertheless, an accurate load current unfold from the VISAR measurement is possible using an MHD code, in conjunction with an optimization algorithm. We will review the VISAR unfold analysis, and show recent current unfolds of MagLIF experiments in comparison to load current measurements using B-dot probes. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. X-ray Imaging of MagLIF Experiments Using a Spherically-Bent Crystal Optic

    Science.gov (United States)

    Harding, E. C.; Gomez, M. R.; Jennings, C. A.; Knapp, P. F.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Hansen, S. B.; Peterson, K. J.; Hahn, K. D.; McBride, R. D.; Rochau, G. A.; Sinars, D. B.; Golovkin, I.

    2015-11-01

    The recent Magnetized Liner Inertial Fusion (MagLIF) experiments performed on Sandia's Z-machine produced significant thermonuclear DD fusion yields that were accompanied by observable x-ray emission [M.R. Gomez et. al., PRL (2014)]. The MagLIF experiments relied on a spherically-bent crystal optic to image portions of the x-ray continuum that were generated by the hot stagnation plasma. The images of stagnation show a long (6 to 8 mm) and narrow (~100 micron) column of x-ray emission with structure in both directions. This structure may be caused by variations in the electron temperature (Te) and density (ne) , as well as opacity variations in the surrounding Be pusher. Here we investigate the possible contributions from each of these effects. We will also discuss the development of a diagnostic technique in which Te and ne of the DD fuel are inferred from spectra emitted by Fe impurities that become ionized to a He-like charge state. Sandia National Labs is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DoE NNSA under contract DE-AC04-94AL85000.

  5. Three Dimensional modeling of instability development in MagLIF loads on the Z Generator

    Science.gov (United States)

    Jennings, C. A.; Harding, E. C.; Gomez, M. R.; Hansen, S. B.; Awe, T. J.; McBride, R. D.; Martin, M. R.; Peterson, K. J.; Chittenden, J. P.

    2015-11-01

    Liners imploded by a fast rising (MagLIF) loads have demonstrated success. Performance may be limited by poor laser coupling in preheating the fuel to be imploded. However time integrated imaging also shows structure in the final fuel assembly indicating potential disruption from instabilities which may also limit neutron yield. We simulate the implosion and stagnation of MagLIF targets using the 3D MHD code GORGON. Generating synthetic diagnostics for comparison with data we discuss how implosion instabilities comparable to those diagnosed with radiography affect fuel compression and confinement. By further comparison of calculation results with PCD traces, time integrated spectra and crystal imaging we discuss how fuel conditions vary in response to feedthrough of implosion instabilities, and how structures formed may affect diagnostic interpretation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  6. A CD25-positive population of activated B1 cells expresses LIFR and responds to LIF

    Directory of Open Access Journals (Sweden)

    Joseph R. Tumang

    2011-03-01

    Full Text Available B1 B cells defend against infectious microorganisms by spontaneous secretion of broadly reactive natural immunoglobulin that appears in the absence of immunization. Among many distinguishing characteristics, B1 B cells display evidence of activation that includes phosphorylated STAT3. In order to identify the origin of pSTAT3 we examined interleukin-2 receptor (IL-2R expression on B1 cells. We found that some (about 1/4 B1a cells express the IL-2R alpha chain, CD25. Although lacking CD122 and unresponsive to IL-2, B1a cells marked by CD25 express increased levels of activated signaling intermediates, interruption of which results in diminished CD25. Further, CD25+ B1a cells contain most of the pSTAT3 found in the B1a population as a whole. Moreover, CD25+ B1a cells express leukemia inhibitory factor receptor (LIFR, and respond to LIF by upregulating pSTAT3. Together, these results define a new subset of B1a cells that is marked by activation-dependent CD25 expression, expresses substantial amounts of activated STAT3, and contains a functional LIF receptor.

  7. Optimizing ZnS/6LiF scintillators for wavelength-shifting-fiber neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Crow, Lowell [ORNL; Funk, Loren L [ORNL; Hannan, Bruce W [ORNL; Hodges, Jason P [ORNL; Riedel, Richard A [ORNL; Wang, Cai-Lin [ORNL

    2016-01-01

    In this paper we compare the performance of grooved and flat ZnS/6LiF scintillators in a wavelength shifting-fiber (WLSF) detector. Flat ZnS/6LiF scintillators with the thickness L=0.2-0.8 mm were characterized using photon counting and pulse-height analysis and compared to a grooved scintillator of approximately 0.8 mm thick. While a grooved scintillator considerably increases the apparent thickness of the scintillator to neutrons for a given coating thickness, we find that the flat scintillators perform better than the grooved scintillators in terms of both light yield and neutron detection efficiency. The flat 0.8-mm-thick scintillator has the highest light output, and it is 52% higher compared with a grooved scintillator of same thickness. The lower light output of the grooved scintillator as compared to the flat scintillator is consistent with the greater scintillator-WLSF separation and the much larger average emission angle of the grooved scintillator. We also find that the average light cone width, or photon travel-length as measured using time-of-flight powder diffraction of diamond and vanadium, decreases with increasing L in the range of L=0.6-0.8 mm. This result contrasts with the traditional Swank diffusion model for micro-composite scintillators, and could be explained by a decrease in photon diffusion-coefficient or an increase in micro-particle content in the flat scintillator matrix for the thicker scintillators.

  8. Leukemia Inhibitory Factor (LIF Inhibition during Mid-Gestation Impairs Trophoblast Invasion and Spiral Artery Remodelling during Pregnancy in Mice.

    Directory of Open Access Journals (Sweden)

    Amy Winship

    Full Text Available The placenta forms the interface between the maternal and fetal circulation and is critical for the establishment of a healthy pregnancy. Trophoblast cell proliferation, migration and invasion into the endometrium are fundamental events in the initiation of placentation. Leukemia inhibitory factor (LIF has been shown to promote trophoblast invasion in vitro, however its precise role in trophoblast invasion in vivo is unknown. We hypothesized that LIF would be required for normal trophoblast invasion and spiral artery remodeling in mice. Both LIF and its receptor (LIFRα co-localized with cytokeratin-positive invasive endovascular extravillous trophoblasts (EVT in mouse implantation sites during mid-gestation. Temporally blocking LIF action during specific periods of placental development via administration of our unique LIFRα antagonist, PEGLA, resulted in abnormal trophoblast invasion and impaired spiral artery remodeling compared to PEG control. PEGLA-treated mouse decidual vessels were characterized by retention of α-smooth muscle actin (αSMA-positive vascular smooth muscle cells (VSMCs, while PEG control decidual vessels were remodelled by cytokeratin-positive trophoblasts. LIF blockade did not alter F4/80-positive decidual macrophage numbers between treatment groups, but resulted in down-regulation of decidual transcript levels of monocyte chemoattractant protein-1 (MCP-1 and interleukin-10 (IL-10, which are important immune cell activation factors that promote spiral artery remodeling during pregnancy. Our data suggest that LIF plays an important role in trophoblast invasion in vivo and may facilitate trophoblast-decidual-immune cell cross talk to enable adequate spiral artery remodeling.

  9. Changes in Expression of LIF and LIFR during Experimental Periodontal Remodeling%实验性牙周改建中 LIF 和 LIFR 的表达变化

    Institute of Scientific and Technical Information of China (English)

    梁又德; 杨旭; 刘莹; 杨芬; 巫家宝; 高丽萍; 刘学

    2014-01-01

    目的:观察大鼠牙周改建中白血病抑制因子(leukemia inhibitory factor,LIF)与白血病抑制因子受体(leu-kemia inhibitory factor receptor,LIFR)的表达变化。方法选用24只6-7周龄雌性 Wistar 大鼠,每只大鼠上颌左右两侧分别为实验侧和对照侧,建立大鼠实验性牙移动的模型。将大鼠随机分成3组,分别在加力后3、7、14 d处死动物。制备标本,用免疫组化染色法检测 LIF 和 LIFR 在大鼠牙周组织中的表达,并采用计算机图像分析软件Image J 对各组 LIF 和 LIFR 在牙周组织中的表达强度进行定量分析。结果LIF 和 LIFR 在正常牙周膜中表达较弱,且主要分布在成纤维细胞、血管内皮细胞、破骨细胞、成骨细胞之中,加力后,实验组表达显著增加。且 LIF 和LIFR 各天之间表达强弱各不相同。在压缩侧,LIF 和 LIFR 的表达在第14天最强,其中 LIF 第14天的表达显著高于第7天(P <0.05);LIFR 在第14天的表达亦显著高于第3天(P <0.01)和第7天(P <0.01)。在牵张侧,LI-FR 在第14天表达最强,且比第3天和第7天表达显著增高(均 P <0.01),而 LIF 表达在各天之间无明显的统计学差异。结论LIF 和 LIFR 的表达呈规律性的变化,参与了牙齿移动过程中的牙周组织改建。%Objective To investigate the changes in the expression of leukemia inhibitory factor (LIF)and leukemia inhibitory factor receptor(LIFR)in periodontal remodeling in rats.Methods Experimental model of tooth movement was established in 24 female Wistar rats aged 7 weeks. The left side of upper jaw of each rat was set as experimental side,and the right side as control side.The model rats were randomly divided into three groups,and then were sacrificed after 3,7 and 14 days,respectively.The upper jaw and periodontal tissue were selected for specimen prepa-ration.The expression of LIF and LIFR in periodontal tissue was

  10. Food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, T.

    1986-01-01

    The proposed use of gamma radiation from cobalt 60 and cesium 137 for food irradiation in the United Kingdom is discussed, with particular reference to the possible dangers and disadvantages to the safety and wholesomeness of the food.

  11. Analysis of rocking curve measurements of LiF flight crystals for the objective crystal spectrometer on SPECTRUM-X-GAMMA

    DEFF Research Database (Denmark)

    Halm, I.; Wiebicke, H.-J.; Geppert, U.R.M.E.;

    1993-01-01

    The Objective Crystal Spectrometer on the SPECTRUM-X-GAMMA satellite will use three types of natural crystals LiF(220), Si(111), RAP(001), and a multilayer structure providing high-resolution X- ray spectroscopy of Fe, S, O, and C line regions of bright cosmic X-ray sources. 330 - 360 LiF(220...

  12. Analysis of rocking curve measurements of LiF flight crystals for the objective crystal spectrometer on SPECTRUM-X-GAMMA

    DEFF Research Database (Denmark)

    Halm, I.; Wiebicke, H.-J.; Geppert, U.R.M.E.

    1993-01-01

    The Objective Crystal Spectrometer on the SPECTRUM-X-GAMMA satellite will use three types of natural crystals LiF(220), Si(111), RAP(001), and a multilayer structure providing high-resolution X- ray spectroscopy of Fe, S, O, and C line regions of bright cosmic X-ray sources. 330 - 360 LiF(220) cr...

  13. [Food irradiation].

    Science.gov (United States)

    Migdał, W

    1995-01-01

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

  14. LiF - a spectroscopic method for rare earth elements identification

    Science.gov (United States)

    Fuchs, Margret; Gloaguen, Richard; Beyer, Jan; Jacob, Sandra; Heitmann, Johannes

    2016-04-01

    Laser-induced fluorescence (LiF) has a great potential for the exploration and identification of rare earth elements (REE) in natural environments. This spectroscopic technique can provide an efficient way to secure resource availability, while the economic and ecological costs are reduced. No time-consuming sample preparation and analysis is needed prior to decisions along the raw material processing chain. Such non-destructive approaches allow for a fast access to analytical results and hence, are the basis for an immediate adjustment of processing steps. The method uses the material-specific luminescence emissions that are induced by laser-stimulation of a certain wavelength. The distinct emission lines of REE make them well suited for the development of a LiF-based exploration technique. However, typical REE emission peaks known from the free elements may shift or be masked in natural materials due to their position in the crystal lattice, varying compositions of minerals or other natural conditions such as water content. The natural variability therefore, demands for comprehensive investigations of REE and their spectral characteristics in minerals. To identify those spectral information that are robust and unequivocal, we analyse spectra of REE standards measured in different matrix minerals including phosphates and fluorides. We use variable laser wavelengths from UV (325 nm) to green (532 nm) and a detection range from 340 nm to 1080 nm. Results show spectral characteristics that sort REE in three groups due to: no distinct emission lines, absorption features, distinct luminescence emission lines. Measured in different matrix minerals, we determine shifts for some of the spectral features and some disappear or decline in intensity. Changing the wavelength of the laser allows for a more selective stimulation of REE emissions, especially wavelengths longer than UV can reduce the unspecific emission of all luminescent components of a sample and thus enhance

  15. Extreme UV and X-ray scattering measurements from a rough LiF crystal surface characterized by electron micrography

    DEFF Research Database (Denmark)

    Alehyane; Arbaoui; Barchewitz

    1989-01-01

    XUV and X-ray scattering by a LiF crystal is measured. The angular distribution of the scattered radiation (ADSR) reveals characteristic features, side peaks or asymmetry. The surface of the sample is statistically characterized by a microdensitometer analysis of electron micrographs resolving th...

  16. Qualification study of LiF flight crystals for the objective crystal spectrometer on the SPECTRUM-X-GAMMA satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Rasmussen, I.; Schnopper, Herbert W.;

    1992-01-01

    The Objective Crystal Spectrometer (OXS) on the SPECTRUM-X-GAMMA satellite will carry these types of natural crystals LiF(220), Ge(111) and RAP(001). They will be used to study, among others, the H- and the He-like emission from the cosmically important elements Fe, S, Ar and O. More than 300 Li...

  17. Siim Nestor soovitab : Bell Orchestre. DJ Deep ja TRL. Akrobatik ja MC Mr.Lif. Black Dice / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2008-01-01

    Muusikaüritustest: Kanada post-rock ansambel Bell Orchestre12. sept. Tallinnas klubis Juuksur, DJ Deep 12. sept. Tallinna Linnahalli ruumides Plektrumi klubiööl (vt. www.plektrumfestival.ee), Akrobatik ja Mr.Lif 12. sept. Tartus klubis Illusion, New Yorgi kollektiiv Black Dice 17. sept. Tallinnas Von Krahlis

  18. Siim Nestor soovitab : Bell Orchestre. DJ Deep ja TRL. Akrobatik ja MC Mr.Lif. Black Dice / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2008-01-01

    Muusikaüritustest: Kanada post-rock ansambel Bell Orchestre12. sept. Tallinnas klubis Juuksur, DJ Deep 12. sept. Tallinna Linnahalli ruumides Plektrumi klubiööl (vt. www.plektrumfestival.ee), Akrobatik ja Mr.Lif 12. sept. Tartus klubis Illusion, New Yorgi kollektiiv Black Dice 17. sept. Tallinnas Von Krahlis

  19. Autotaxin-mediated lipid signaling intersects with LIF and BMP signaling to promote the naive pluripotency transcription factor program

    Science.gov (United States)

    Kime, Cody; Sakaki-Yumoto, Masayo; Goodrich, Leeanne; Hayashi, Yohei; Sami, Salma; Derynck, Rik; Asahi, Michio; Panning, Barbara; Yamanaka, Shinya; Tomoda, Kiichiro

    2016-01-01

    Developmental signaling molecules are used for cell fate determination, and understanding how their combinatorial effects produce the variety of cell types in multicellular organisms is a key problem in biology. Here, we demonstrate that the combination of leukemia inhibitory factor (LIF), bone morphogenetic protein 4 (BMP4), lysophosphatidic acid (LPA), and ascorbic acid (AA) efficiently converts mouse primed pluripotent stem cells (PSCs) into naive PSCs. Signaling by the lipid LPA through its receptor LPAR1 and downstream effector Rho-associated protein kinase (ROCK) cooperated with LIF signaling to promote this conversion. BMP4, which also stimulates conversion to naive pluripotency, bypassed the need for exogenous LPA by increasing the activity of the extracellular LPA-producing enzyme autotaxin (ATX). We found that LIF and LPA-LPAR1 signaling affect the abundance of signal transducer and activator of transcription 3 (STAT3), which induces a previously unappreciated Kruppel-like factor (KLF)2-KLF4-PR domain 14 (PRDM14) transcription factor circuit key to establish naive pluripotency. AA also affects this transcription factor circuit by controlling PRDM14 expression. Thus, our study reveals that ATX-mediated autocrine lipid signaling promotes naive pluripotency by intersecting with LIF and BMP4 signaling. PMID:27738243

  20. Effects of specific and prolonged expression of zebrafish growth factors, Fgf2 and Lif in primordial germ cells in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Ten-Tsao, E-mail: wong20@purdue.edu [Department of Animal Sciences, Purdue University, 901 W. State Street, West Lafayette, IN 47907 (United States); Collodi, Paul [Department of Animal Sciences, Purdue University, 901 W. State Street, West Lafayette, IN 47907 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer We discovered that nanos3 3 Prime UTR prolonged PGC-specific protein expression up to 26 days. Black-Right-Pointing-Pointer Expression of Fgf2 in PGCs significantly increased PGC number at later developmental stages. Black-Right-Pointing-Pointer Expression of Lif in PGCs resulted in a significant disruption of PGC migration. Black-Right-Pointing-Pointer Lif illicited its effect on PGC migration through Lif receptor a. Black-Right-Pointing-Pointer Our approach could be used to achieve prolonged PGC-specific expression of other proteins. -- Abstract: Primordial germ cells (PGCs), specified early in development, proliferate and migrate to the developing gonad before sexual differentiation occurs in the embryo and eventually give rise to spermatogonia or oogonia. In this study, we discovered that nanos3 3 Prime UTR, a common method used to label PGCs, not only directed PGC-specific expression of DsRed but also prolonged this expression up to 26 days post fertilization (dpf) when DsRed-nanos3 3 Prime UTR hybrid mRNAs were introduced into 1- to 2-cell-stage embryos. As such, we employed this knowledge to express zebrafish leukemia inhibitory factor (Lif), basic fibroblast growth factor (Fgf2) and bone morphogenetic protein 4 (Bmp4) in the PGCs and evaluate their effects on PGC development in vivo for over a period of 3 weeks. The results show that expression of Fgf2 significantly increased PGC number at 14- and 21-dpf while Bmp4 resulted in severe ventralization and death of the embryos by 3 days. Expression of Lif resulted in a significant disruption of PGC migration. Mopholino knockdown experiments indicated that Lif illicited its effect on PGC migration through Lif receptor a (Lifra) but not Lifrb. The general approach described in this study could be used to achieve prolonged PGC-specific expression of other proteins to investigate their roles in germ cell and gonad development. The results also indicate that zebrafish PGCs

  1. Stopping powers of LiF thin films deposited onto self-supporting Al foils for swift protons

    Energy Technology Data Exchange (ETDEWEB)

    Damache, Smail [Division de Physique, CRNA, 02 Bd. Frantz Fanon, B.P. 399 Alger-gare, Algiers (Algeria); Moussa, Djamel [Université des Sciences et de la Technologie H. Boumediene (USTHB), Faculté de Physique, B.P. 32 El-Alia, 16111 Bab-Ezzouar, Algiers (Algeria); Ouichaoui, Saâd, E-mail: souichaoui@gmail.com [Université des Sciences et de la Technologie H. Boumediene (USTHB), Faculté de Physique, B.P. 32 El-Alia, 16111 Bab-Ezzouar, Algiers (Algeria)

    2013-08-01

    The energy losses of ∼(0.273–3.334) MeV protons in LiF thin films deposited by vacuum evaporation onto self-supporting Al foils have been measured using the transmission method. The thicknesses of selected and used LiF/Al target samples were accurately determined via systematic energy loss measurements for alpha particles from a very thin mixed {sup 241}Am/{sup 239}Pu/{sup 233}U radioactive source. The samples were investigated in detail for their stoichiometry and their impurity contents by backscattering Rutherford spectrometry and nuclear reaction analysis. Then, LiF stopping powers have been determined with overall relative uncertainty of less than 2.7% arising mainly from errors in the determination of target sample thicknesses. These S(E) data are reported and discussed in comparison to previous experimental data sets from the literature and to values calculated by the Sigmund–Schinner binary collision stopping theory both for molecular LiF, and for the LiF compound assuming Bragg–Kleeman’s additivity rule. Our S(E) data show to be in excellent agreement with the latter theory for molecular LiF over the whole proton energy range explored, which supports the use of modified electronic hydrogen wave functions for evaluating atomic shell corrections in the case of low-Z{sub 2} target materials. In contrast, they exhibit a slightly increasing deviation from theoretical values derived for the LiF compound with assuming stopping force additivity as the proton energy decreases from E ≈ 400 keV towards lower proton velocities. This deviation in excess relative to experimental data, amounting only up to (at most) ∼2.5%, can be ascribed to strong effects of 2s-state valence electrons of Li atoms within the LiF compound. Besides, the comparison to values calculated by the SRIM-2008 computer code indicates that this program satisfactorily accounts for our S(E) data above E ≈ 1.30 MeV but underestimates them with substantially increasing deviations (up to

  2. Temperature and velocity fields in natural convection by PIV and LIF

    DEFF Research Database (Denmark)

    Meyer, Knud Erik; Larsen, Poul Scheel; Westergaard, C. H.

    2002-01-01

    plate and cooled walls is 1.4×10^10. The flow is turbulent and is similar to some indoor room flows. Combined Particle Image Velocimetry (PIV) and Planar Light Induced Fluorescence (LIF) are used to measure local velocities and temperatures. Data measured in a symmetry plane parallel to a sidewall......Natural convection in a cubical cavity (L = 250 mm) filled with water is created by heating a square plate (0.5 L) centred in the bottom wall and by cooling the sidewalls, while the remaining walls are insulated. The Rayleigh number based on cavity side length and temperature difference between...... are presented in terms of mean velocities and temperature and in terms turbulent quantities including Reynolds fluxes. The flow consists a plume rising above the heated plate into an almost stagnant fluid with a weakly stratified temperature field, as well as thin buoyancy driven boundary layers down...

  3. Improved sample preparation for CE-LIF analysis of plant N-glycans.

    Science.gov (United States)

    Nagels, Bieke; Santens, Francis; Weterings, Koen; Van Damme, Els J M; Callewaert, Nico

    2011-12-01

    In view of glycomics studies in plants, it is important to have sensitive tools that allow one to analyze and characterize the N-glycans present on plant proteins in different species. Earlier methods combined plant-based sample preparations with CE-LIF N-glycan analysis but suffered from background contaminations, often resulting in non-reproducible results. This publication describes a reproducible and sensitive protocol for the preparation and analysis of plant N-glycans, based on a combination of the 'in-gel release method' and N-glycan analysis on a multicapillary DNA sequencer. Our protocol makes it possible to analyze plant N-glycans starting from low amounts of plant material with highly reproducible results. The developed protocol was validated for different plant species and plant cells.

  4. Integrative Analysis of Hot Spot Conditions in MagLIF Experiments

    Science.gov (United States)

    Knapp, Patrick; Gomez, Matthew; Harding, Eric; Hansen, Stephanie; Hahn, Kelly; Geissel, Matthias; Chandler, Gordon; Smith, Ian; Slutz, Steve; Jennings, Chris; Martin, Matthew; Schmit, Paul; Peterson, Kyle; Rochau, Gregory; McBride, Ryan; Sinars, Daniel

    2016-10-01

    A large data set incorporating all available neutron and x-ray data is used to analyze a broad range of Magnetized Liner Inertial Fusion (MagLIF) experiments conducted on the Z machine at Sandia National Laboratories over the past two years. Electron and ion temperatures, electron density, mix fraction, burn volume and duration, and neutron and x-ray yields are all measured on each experiment; several through multiple independent methods. Complementary methods are used to infer the hot spot energy and pressure, and trends are analyzed. The results are placed in the context of accepted performance metrics for Magneto-Inertial Fusion. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE.

  5. Production of excitons in grazing collisions of protons with LiF surfaces: An onion model

    Energy Technology Data Exchange (ETDEWEB)

    Miraglia, J. E.; Gravielle, M. S. [Instituto de Astronomia y Fisica del Espacio, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Casilla de Correo 67, Sucursal 28, (C1428EGA) Buenos Aires (Argentina)

    2011-12-15

    In this work we evaluate the production of excitons of a lithium fluoride crystal induced by proton impact in the intermediate and high energy regime (from 100 keV to 1 MeV). A simple model is proposed to account for the influence of the Coulomb grid of the target by dressing crystal ions to transform them in what we call onions. The excited states of these onions can be interpreted as excitons. Within this model, total cross section and stopping power are calculated by using the first Born and the continuum distorted-wave (CDW) eikonal initial-state (EIS) approximations. We found that between 7 and 30 excitons per incident proton are produced in grazing collisions with LiF surfaces, becoming a relevant mechanism of inelastic transitions.

  6. Water stress assessment of cork oak leaves and maritime pine needles based on LIF spectra

    Science.gov (United States)

    Lavrov, A.; Utkin, A. B.; Marques da Silva, J.; Vilar, Rui; Santos, N. M.; Alves, B.

    2012-02-01

    The aim of the present work was to develop a method for the remote assessment of the impact of fire and drought stress on Mediterranean forest species such as the cork oak ( Quercus suber) and maritime pine ( Pinus pinaster). The proposed method is based on laser induced fluorescence (LIF): chlorophyll fluorescence is remotely excited by frequency-doubled YAG:Nd laser radiation pulses and collected and analyzed using a telescope and a gated high sensitivity spectrometer. The plant health criterion used is based on the I 685/ I 740 ratio value, calculated from the fluorescence spectra. The method was benchmarked by comparing the results achieved with those obtained by conventional, continuous excitation fluorometric method and water loss gravimetric measurements. The results obtained with both methods show a strong correlation between them and with the weight-loss measurements, showing that the proposed method is suitable for fire and drought impact assessment on these two species.

  7. Diagnosing the Stagnation Conditions of MagLIF Implosions Using High-Resolution Spectroscopy

    Science.gov (United States)

    Harding, Eric

    2016-10-01

    An inertial fusion concept known as Magnetized Liner Inertial Fusion (MagLIF) is currently being pursued on the Z-machine at Sandia National Laboratory. Electrical current from the Z-machine is directly coupled onto the outside surface of a beryllium tube known as a ``liner'' causing it to implode. The liner contains gaseous deuterium (D2) fuel, which is pre-magnetized, pre-heated, and then compressed by the imploding walls of the liner. Target implosions of this type have produced thermonuclear plasmas that generated 2e12 DD neutrons [M.R. Gomez et al., PRL 113, 155003 (2014)]. For the first time we have accurately measured the space-dependent, fuel conditions at the time of stagnation. In addition, the state of the compressed Be liner was determined. This was accomplished by the simultaneous use of high-resolution, x-ray spectroscopic and imaging diagnostics. These new measurements relied on the observation of K-shell spectra emitted by microscopic iron and nickel impurities that naturally occur in the Be. The measurements currently indicate that the non-uniformity of the x-ray emission from the fuel is due to variations in the fuel conditions. Ultimately, the data provides critical insight into the performance of the MagLIF target and will further enable us to enhance the target design. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract No. DE-AC04-94AL85000.

  8. High-level expression and efficient one-step chromatographic purification of a soluble human leukemia inhibitory factor (LIF) in Escherichia coli.

    Science.gov (United States)

    Imaizumi, Keitaro; Nishikawa, Shin-Ichi; Tarui, Hiroshi; Akuta, Teruo

    2013-07-01

    Leukemia inhibitor factor (LIF) is a three disulfide bridge-containing cytokine with numerous regulatory effects. In this report, we present the high level expression of a soluble recombinant human LIF (rhLIF) in Escherichia coli. A codon-optimized Profinity eXact™-tagged hLIF cDNA was cloned into pET3b vector, and transformed into E. coli OrigamiB(DE3) harboring the bacterial thioredoxin coexpression vector. By using an enzyme-based glucose release system (EnBase®) and high-aeration shake flask (Ultra Yield Flask™), the yield of soluble proteins was significantly improved in comparison to commonly-used 2 × YT media. The recombinant protein was purified via a single chromatographic step using an affinity tag-based protein purification system that processed by cleavage with sodium fluoride, resulting in the complete proteolytic removal the N-terminal tag. Soluble rhLIF yield was estimated to be approximately 1mg/g of wet weight cells, with above 98% purity. The rhLIF protein specifically inhibited the proliferation of the murine myeloblastic leukemia M1 cell in a dose-dependent manner, and induced Stat3 phosphorylation in mouse ES cells. This novel expression and purification protocol for the production of recombinant hLIF is a simple, suitable, and effective method.

  9. Thermoluminescent sensitivity of single clad neodymium doped SiO2 optical fibres measured with 6 MeV photons

    Science.gov (United States)

    Saeed, M. A.; Hossain, I.; Hida, N.; Wagiran, H.

    2013-10-01

    This study investigates the thermoluminescent sensitivity of neodymium doped SiO2 optical fibre with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MeV photon irradiations. The TL responses of the neodymium doped silica fibres are compared with available TLD-100 dosimeter in order to determine the suitability as a TL material. We found that the TLD-100 and neodymium doped silica fibre have a significant linear signal to dose relationship. Neodymium doped fibres sensitivity is approximately 11% of TLD-100.

  10. Dependence of the rate of LiF ion pairing on the description of molecular interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pluharova, Eva; Baer, Marcel D.; Schenter, Gregory K.; Jungwirth, Pavel; Mundy, Christopher J.

    2016-03-03

    We present an analysis of the dynamics of ion-pairing of Lithium Fluoride (LiF) in aqueous solvent using both detailed molecular simulation as well as reduced models within a Gener- alized Langevin Equation (GLE) framework. We explored the sensitivity of the ion-pairing phenomena to the details of descriptions of molecular interaction, comparing two empirical potentials to explicit quantum based density functional theory. We find quantitative differences in the potentials of mean force for ion-pairing as well as time dependent frictions that lead to variations in the rate constant and reactive flux correlation functions. These details reflect differences in solvent response to ion-pairing between different representations of molecular interaction and influence anharmonicity of the dynamic response. We find that the short time anharmonic response is recovered with a GLE parameterization. Recovery of the details of long time response may require extensions to the reduced model. We show that the utility of using a reduced model leads to a straight forward application of variational transition state the- ory concepts to the condensed phase system. The significance of this is reflected in the analysis of committor distributions and the variation of planar hypersurfaces, leading to an improved understanding of factors that determine the rate of LiF ion-pairing. CJM and GKS are supported by the U.S. Department of Energy‘s (DOE) Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest Na- tional Laboratory (PNNL) is operated for the Department of Energy by Battelle. MDB is grateful for the support of Laboratory Directed Research and Development funding under the auspices of PNNL’s Laboratory Initiative Materials Synthesis and Simulation across Scales (MS3). Additional computing resources were generously allocated by PNNL’s Institutional Computing program. EP acknowledges support from PNNL’s Alternate Sponsored

  11. A new approach for cloning hLIF cDNA from genomic DNA isolated from the oral mucous membrane.

    Science.gov (United States)

    Cui, Y H; Zhu, G Q; Chen, Q J; Wang, Y F; Yang, M M; Song, Y X; Wang, J G; Cao, B Y

    2011-11-25

    Complementary DNA (cDNA) is valuable for investigating protein structure and function in the study of life science, but it is difficult to obtain by traditional reverse transcription. We employed a novel strategy to clone human leukemia inhibitory factor (hLIF) gene cDNA from genomic DNA, which was directly isolated from the mucous membrane of mouth. The hLIF sequence, which is 609 bp long and is composed of three exons, can be acquired within a few hours by amplifying each exon and splicing all of them using overlap-PCR. This new approach developed is simple, time- and cost-effective, without RNA preparation or cDNA synthesis, and is not limited to the specific tissues for a particular gene and the expression level of the gene.

  12. Electrostimulation of the magnetoplastic effect in LiF crystals by an "internal" electric field induced during indentation

    Science.gov (United States)

    Galustashvili, M. V.; Driaev, D. G.; Akopov, F. Kh.; Tsakadze, S. D.

    2013-08-01

    Indented LiF crystals demonstrate a change in the length of the dislocation rosette rays during their exposure to jointly acting dc magnetic and electric fields. It is shown that magnetic field with induction B = 1 T causes the electrostimulation or electrosuppression depending on the magnitude and direction of the external electric field with respect to the "internal" electric field induced by the charge transfer due to dislocations moving during the indentation.

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

    CERN Document Server

    Kaskanov, G Y

    2003-01-01

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

  14. Three LIF-dependent signatures and gene clusters with atypical expression profiles, identified by transcriptome studies in mouse ES cells and early derivatives

    Directory of Open Access Journals (Sweden)

    Hummel Oliver

    2009-02-01

    Full Text Available Abstract Background Mouse embryonic stem (ES cells remain pluripotent in vitro when grown in the presence of the cytokine Leukaemia Inhibitory Factor (LIF. Identification of LIF targets and of genes regulating the transition between pluripotent and early differentiated cells is a critical step for understanding the control of ES cell pluripotency. Results By gene profiling studies carried out with mRNAs from ES cells and their early derivatives treated or not with LIF, we have identified i LIF-dependent genes, highly expressed in pluripotent cells, whose expression level decreases sharply upon LIF withdrawal [Pluri genes], ii LIF induced genes [Lifind genes] whose expression is differentially regulated depending upon cell context and iii genes specific to the reversible or irreversible committed states. In addition, by hierarchical gene clustering, we have identified, among eight independent gene clusters, two atypical groups of genes, whose expression level was highly modulated in committed cells only. Computer based analyses led to the characterization of different sub-types of Pluri and Lifind genes, and revealed their differential modulation by Oct4 or Nanog master genes. Individual knock down of a selection of Pluri and Lifind genes leads to weak changes in the expression of early differentiation markers, in cell growth conditions in which these master genes are still expressed. Conclusion We have identified different sets of LIF-regulated genes depending upon the cell state (reversible or irreversible commitment, which allowed us to present a novel global view of LIF responses. We are also reporting on the identification of genes whose expression is strictly regulated during the commitment step. Furthermore, our studies identify sub-networks of genes with a restricted expression in pluripotent ES cells, whose down regulation occurs while the master knot (composed of OCT4, SOX2 and NANOG is still expressed and which might be down

  15. Selective radiative cooling with MgO and/or LiF layers

    Science.gov (United States)

    Berdahl, P.H.

    1984-09-14

    A selective radiation cooling material which is absorptive only in the 8 to 13 microns wavelength range is accomplished by placing ceramic magnesium oxide and/or polycrystalline lithium fluoride on an infrared-reflective substrate. The reflecting substrate may be a metallic coating, foil or sheet, such as aluminum, which reflects all atmospheric radiation from 0.3 to 8 microns, the magnesium oxide and lithium fluoride being nonabsorptive at those wavelengths. MgO and/or LiF layer is diffusely scattering, but still nonabsorbing, in the wavelength range of 0.3 to 8 microns. At wavelengths from 8 to 13 microns, the magnesium oxide and lithium fluoride radiate power through the ''window'' in the atmosphere, and thus remove heat from the reflecting sheet of material and the attached object to be cooled. At wavelengths longer than 13 microns, the magnesium oxide and lithium fluoride reflects the atmospheric radiation back into the atmosphere. This high reflectance is only obtained if the surface is sufficiently smooth: roughness on a scale of 1 micron is permissible but roughness on a scale of 10 microns is not. An infrared-transmitting cover or shield is mounted in spaced relationship to the material to reduce convective heat transfer. If this is utilized in direct sunlight, the infrared transmitting cover or shield should be opaque in the solar spectrum of 0.3 to 3 microns.

  16. Coherent control of charge exchange in strong-field dissociation of LiF

    Science.gov (United States)

    Armstrong, Greg; Esry, Brett

    2016-05-01

    The alkali-metal-halides family of molecules are useful prototypes in the study of laser-assisted charge exchange. Typically these molecules possess a field-free crossing between the ionic and covalent diabatic Born-Oppenheimer potential curves, leading to Li+ + F- and Li + F in LiF. These channels are energetically well-separated from higher-lying potentials, and may be easily distinguished experimentally. Moreover, charge exchange involves non-adiabatic transitions between the ionic and covalent channels, thereby allowing the investigation of physics beyond the Born-Oppenheimer approximation. The focus of this work is to control the preference between ionic and covalent dissociative products. We solve the time-dependent Schrödinger equation for the nuclear motion in full dimensionality, and investigate a pump-probe scheme for charge-exchange control. The degree of control is investigated by calculating the kinetic-energy release spectrum as a function of pump-probe delay for the ionic and covalent fragments. This work is supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.

  17. Developing a Pre-Heat Platform for MagLIF with Z-Beamlet

    Science.gov (United States)

    Geissel, Matthias; Harvey-Thompson, Adam J.; Awe, T. J.; Bliss, D. E.; Glinsky, M. E.; Campbell, E. M.; Gomez, M. R.; Harding, E.; Hansen, S. B.; Jennings, C. A.; Kimmel, M. W.; Knapp, P. F.; Lewis, S. M.; McBride, R. D.; Peterson, K.; Schollmeier, M.; Scoglietti, D. J.; Sefkow, A. B.; Shores, J. E.; Sinars, D. B.; Rochau, G. A.; Slutz, S. A.; Smith, I. C.; Weiss, M. R.; Porter, J. L.

    2016-10-01

    Sandia's Magnetized Liner Inertial Fusion Program has put one of the main objectives towards developing standard platform for a `preconditioned' target, providing a scenario that reproducibly delivers pre-heated fuel. The majority of this effort has been done at the ``Pecos'' Target Area using Sandia's Z-Beamlet laser to provide the pre-heat energy, just like for fully integrated MagLIF experiments. The nature and magnitude of Laser-Plasma-Instabilities during this process are particularly important, since they can lead to less energy in the fuel (backscatter processes) or to energy deposition in less desirable areas (filamentation/scatter). We present results for Stimulated Brillouin Backscatter and forward scatter, and show the effect of the laser pulse shape to laser-entrance-hole transmission and blast wave propagation in the fuel. Sandia is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. DOE's Nat'l Nucl. Sec. Admin. under contract DE-AC04-94AL85000.

  18. Analysis of laser preconditioning experiments on Z Beamlet Laser for MagLIF

    Science.gov (United States)

    Glinsky, Michael; Weis, Matthew; Harvey-Thompson, Adam; Geissel, Matthias; Jennings, Christopher; Nagayama, Taisuke; Peterson, Kyle

    2016-10-01

    Presented is an analysis of a series of laser preconditioning experiments on the Z Beamlet Laser (ZBL). These experiments examine the penetration of the laser through the plastic window (a few microns thick), the energy deposition into a gas behind the window, and the resulting density variations in the gas. The ZBL is a glass laser, frequency doubled to 527 μm, capable of delivering up to 4 kJ on target with a pulse length of a few ns. This is the same laser that is used to preheat the fuel in the MagLIF scheme before it is magnetically imploded on the Z generator. The design space for the laser pulse is explored in a series of experiments. Diagnostics include transmitted energy, backscattered energy, x-ray self emission images, and density shadowgrams at several times. These results are matched against HYDRA simulations using the uncertainty quantification engine Dakota. The potential for SBS, SRS, and filamentation are evaluated. Estimates of the energy deposition profile and disposition of the window (important because of potential mix with the fuel) are obtained with uncertainty. Work was performed by Sandia National Laboratories for USDoE under contract DE-AC04-94AL85000. SAND NO. 2016-6689C.

  19. Laser-only experiments in support of the MagLIF scheme

    Science.gov (United States)

    Harvey-Thompson, Adam; Slutz, Stephen; Sefkow, Adam; Bliss, David; Geissel, Matthias; Gomez, Matthew; Harding, Eric; Sinars, Daniel; Smith, Ian; Fiksel, Gennady; Wei, Mingsheng

    2013-10-01

    The MagLIF inertial confinement fusion scheme involves imploding a cylindrical liner with the 24 MA, 100 ns rise-time current pulse delivered by the Z generator which compresses a D2 fuel that is magnetized with an external magnetic field and preheated with an energy source - currently the 2.5 kJ Z-Beamlet laser. For this scheme to be successful, laser energy has to be coupled effectively into the fuel and electron thermal conduction needs to be suppressed by the applied magnetic field. Laser only experiments at ZBL and Omega EP can potentially test these aspects of the scheme, exploring the physics and aiding target design. Completed and planned experiments are discussed. This work was supported by Sandia National Laboratories, a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DoE's NNSA under contract DE-AC04-94AL85000.

  20. Laser Pre-Heat Studies for MagLIF with Z-Beamlet

    Science.gov (United States)

    Geissel, Matthias; Harvey-Thompson, Adam J.; Awe, T. J.; Gomez, M. R.; Harding, E.; Jennings, C.; Kimmel, M. W.; Knapp, P.; Peterson, K.; Schollmeier, M.; Sefkow, A. B.; Shores, J. E.; Sinars, D. B.; Slutz, S. A.; Smith, I. C.; Speas, C. S.; Vesey, R. A.; Porter, J. L.; Campbell, E. M.; Lewis, S. M.

    2015-11-01

    Magnetized Liner Inertial Confinement Fusion (MagLIF) relies on strong pre-heat of the fuel, typically hundreds of eV. Z-Beamlet delivers up to 4 kJ of laser energy to the target to achieve this goal. Over the last year, several experimental campaigns at the Pecos target area of Sandia's Z-Backlighter Facility and in the center section of the Z-Accelerator have been performed to investigate pre-heat. Primary objectives of these campaigns were the transmission through the laser entrance hole (LEH) in dependence of window thicknesses and focus parameters (including phase plate smoothing), as well as energy coupling to the gaseous fuel. The applied diagnostic suite included a wide range of time integrated and time-resolved X-ray imaging devices, spectrometers, backscatter monitors, a full-beam laser transmission calorimeter, and X-ray diodes.We present the findings of these studies, looking ahead towards a standard pre-heat platform. Sandia National Labs is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Dept. of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Differentiating Different Modeling Assumptions in Simulations of MagLIF loads on the Z Generator

    Science.gov (United States)

    Jennings, C. A.; Gomez, M. R.; Harding, E. C.; Knapp, P. F.; Ampleford, D. J.; Hansen, S. B.; Weis, M. R.; Glinsky, M. E.; Peterson, K.; Chittenden, J. P.

    2016-10-01

    Metal liners imploded by a fast rising (MagLIF experiments have had some success. While experiments are increasingly well diagnosed, many of the measurements (particularly during stagnation) are time integrated, limited in spatial resolution or require additional assumptions to interpret in the context of a structured, rapidly evolving system. As such, in validating MHD calculations, there is the potential for the same observables in the experimental data to be reproduced under different modeling assumptions. Using synthetic diagnostics of the results of different pre-heat, implosion and stagnation simulations run with the Gorgon MHD code, we discuss how the interpretation of typical Z diagnostics relate to more fundamental simulation parameters. We then explore the extent to which different assumptions on instability development, current delivery, high-Z mix into the fuel and initial laser deposition can be differentiated in our existing measurements. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DoE's NNSA under contract DE-AC04-94AL85000.

  2. First Results from Laser-Driven MagLIF Experiments on OMEGA: Optimization of Illumination Uniformity

    Science.gov (United States)

    Chang, P.-Y.; Barnak, D. H.; Betti, R.; Davies, J. R.; Fiksel, G.

    2015-11-01

    The physics principles of magnetic liner inertial fusion (MagLIF) are investigated on the Omega Laser Facility using 40 beams for compression and 1 beam for preheating a small (300- μm-radius, 1-mm-long) cylindrical plastic shell. Here we report of the first implosion experiments to optimize the illumination uniformity. These initial experiments do not include laser preheat. The beams in ring 3 and ring 4 around the symmetric axis are used to implode a cylindrical target. Beams in different rings illuminate the target surface with different incident angles, leading to different energy-coupling efficiencies. The beams in ring 3 have a shallower angle of incident than ring 4. When implosion velocities are compared for targets driven by either ring 3 or ring 4, we find that ring 3 couples ~ 40 % less kinetic energy than ring 4. One- and two-dimensional simulations using LILAC (1-D) and FLASH (2-D) are used to compare to the experimental results and to optimize the illumination uniformity. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and by DE-FG02-04ER54786 and DE-FC02-04ER54789 (Fusion Science Center).

  3. Two Dimensional LIF Measurements and Potential Structure of Ion Beam Formation in an Argon Helicon Plasma

    Science.gov (United States)

    Aguirre, Evan; Scime, Earl; Good, Timothy

    2016-10-01

    We report 2-dimensional, spatially resolved observations of ion beam formation in an expanding helicon plasma. Previous studies found that a current free double layer (CFDL) spontaneously arises at low pressure, below 1 mT. We use Laser Induced Fluorescence (LIF), a non-perturbative diagnostic to measure the ion velocity distribution functions (IVDFs) of argon ions both parallel and perpendicular to the background magnetic field. We report ion beam formation as a function of the expansion chamber magnetic field (0-108 G). The ion beam appears peaked in the center of the expansion chamber and decays over a few centimeters radially. We also report the potential structure of the plasma obtained with a planar Langmuir probe. To obtain meaningful Langmuir probe measurements, averages of tens of current-voltage are needed to reduce the effects of large electrostatic fluctuations that arise in plasmas that generate ion beams. We report the dependence of density, electron temperature, and floating potential on radial and axial position in the expansion plume. NSF Award PHYS-1360278.

  4. Preliminary results from the first integrated Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z accelerator

    Science.gov (United States)

    Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Harvey-Thompson, A. J.; Awe, T. J.; Cuneo, M. E.; Geissel, M.; Herrmann, M.; Jennings, C.; Lamppa, D.; Martin, M.; McBride, R. D.; Rovang, D. C.; Sinars, D.; Smith, I. C.

    2013-10-01

    Sandia National Laboratories' Z Machine provides a drive current of up to 27 MA with 100 ns risetime to a magnetically-driven load. Magnetized Liner Inertial Fusion (MagLIF) is the main focus of the inertial confinement fusion program on Z. The MagLIF concept uses an imploding metallic cylindrical liner to compress magnetized, pre-heated fusion fuel. Simulations indicate that fusion yields on the order of 100 kJ (5e16 DT neutrons) are achievable with a drive current of 27 MA in 100 ns, a laser preheat of 8 kJ in 8 ns, an applied axial B-field of 30 T, and deuterium-tritium fusion fuel. The first fully integrated MagLIF experiments are scheduled to be conducted on Z late summer 2013. These tests will utilize a drive current of 16 MA, a laser preheat of 2 kJ in 2 ns, an applied B-field of 10 T, and deuterium fuel. With these reduced parameters, simulations predict yields greater than 1e10 DD neutrons. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. LIF在子痫前期患者血清中的表达与意义%Expression and significance of LIF in patients with preeclampsia

    Institute of Scientific and Technical Information of China (English)

    庞春蓉; 刘蔚; 傅晓冬

    2011-01-01

    目的 测定白血病抑制因子(LIF)在子痫前期患者血清中的表达,探讨其在子痫前期疾病中的作用.方法 采用双抗夹心酶联免疫法(ELISA)检测40例子痫前期孕妇、40例正常妊娠妇女血清中LIF的水平.结果 子痫前期组血清LIF水平低于正常妊娠组(P<0.01);且子痫前期组LIF水平与平均动脉压无相关性.结论 LIF可能参与了子痫前期疾病的病理过程.%Objective To observe the changes of serum leukemia inhibitory factor (LIF) in patients with preeclampsia (PE) and understand the effects of LIF on the pathogenesis of PE.Methods The serum LIF of 40 patients with PE and 40 health gravidas was measured with ELISA.Remits Compared with normal pregnancy group, the serum LIF of PE was significantly reduced P<0.05.Conclusion LIF maybe involve in pathogenic process of preeclampsia.

  6. Yeast DNA ligase IV mutations reveal a nonhomologous end joining function of BRCT1 distinct from XRCC4/Lif1 binding.

    Science.gov (United States)

    Chiruvella, Kishore K; Renard, Brian M; Birkeland, Shanda R; Sunder, Sham; Liang, Zhuobin; Wilson, Thomas E

    2014-12-01

    LIG4/Dnl4 is the DNA ligase that (re)joins DNA double-strand breaks (DSBs) via nonhomologous end joining (NHEJ), an activity supported by binding of its tandem BRCT domains to the ligase accessory protein XRCC4/Lif1. We screened a panel of 88 distinct ligase mutants to explore the structure–function relationships of the yeast Dnl4 BRCT domains and inter-BRCT linker in NHEJ. Screen results suggested two distinct classes of BRCT mutations with differential effects on Lif1 interaction as compared to NHEJ completion. Validated constructs confirmed that D800K and GG(868:869)AA mutations, which target the Lif1 binding interface, showed a severely defective Dnl4–Lif1 interaction but a less consistent and often small decrease in NHEJ activity in some assays, as well as nearly normal levels of Dnl4 accumulation at DSBs. In contrast, mutants K742A and KTT(742:744)ATA, which target the β3-α2 region of the first BRCT domain, substantially decreased NHEJ function commensurate with a large defect in Dnl4 recruitment to DSBs, despite a comparatively greater preservation of the Lif1 interaction. Together, these separation-of-function mutants indicate that Dnl4 BRCT1 supports DSB recruitment and NHEJ in a manner distinct from Lif1 binding and reveal a complexity of Dnl4 BRCT domain functions in support of stable DSB association.

  7. Local BMP-SMAD1 Signaling Increases LIF Receptor-Dependent STAT3 Responsiveness and Primed-to-Naive Mouse Pluripotent Stem Cell Conversion Frequency

    Directory of Open Access Journals (Sweden)

    Kento Onishi

    2014-07-01

    Full Text Available Conversion of EpiSCs to naive ESCs is a rare event that is driven by the reestablishment of the naive transcription factor network. In mice, STAT3 activation is sufficient to drive conversion of EpiSCs to the naive pluripotent stem cell (PSC state. However, the lack of responsiveness of EpiSCs to LIF presents a bottleneck in this conversion process. Here, we demonstrate that local accumulation of BMP-SMAD1 signaling, in cooperation with GP130 ligands, enhances the recovery of LIF responsiveness by directly controlling transcription of the LIF receptor (Lif-r. Addition of BMP and LIF to EpiSCs increases both LIF responsiveness and conversion frequencies to naive PSCs. Mechanistically, we show that the transcriptional cofactor P300 plays a critical role by mediating complex formation between STAT3 and SMAD1. This demonstration of how the local microenvironment or stem cell niche reactivates dormant signaling responsiveness and developmental potential may be applicable to other stem cell niche-containing systems.

  8. Silver nanoparticles on nanopatterned LiF(110) surface studied by extreme ultraviolet light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Giglia, Angelo, E-mail: giglia@iom.cnr.it; Nannarone, Stefano [Istituto Officina dei Materiali - Consiglio Nazionale delle Ricerche, Laboratorio Tecnologie Avanzate e NanoSCienza, Area Science Park Basovizza, S.S. 14 Km 163.5, 34149 Trieste (Italy); Miotti, Paolo [Istituto di Fotonica e Nanotecnologie - Consiglio Nazionale delle Ricerche, Via Trasea 7, 35131 Padova (Italy); Parisse, Pietro [Sincrotrone Trieste S.C.p.A., S.S. 14 km 163.5, 34149 Basovizza, Trieste (Italy)

    2015-12-21

    A LiF(110) surface featuring a ridge-and-valley nanopatterned structure periodic along the [−1,1,0] direction (period and height of the order of 30 nm and 10 nm, respectively) formed by [001] macrosteps exposing (100) and (010) facets was functionalized by rows of Ag nanoparticles and studied by elastic light scattering in the energy range 50–100 eV. Families of diffraction efficiencies curves were taken at grazing incidence angle and fixed photon energy as a function of scattering angle, and elastic scattering curves were taken at fixed scattering angle as a function of energy. The scattering curves presented well-defined features ascribable to the periodicities of the surface, or equivalently to the reciprocal q{sub X} vectors correlated with the power spectral density features of topological images of atomic force microscopy. Other characteristics of the functionalized surface, including the height of ridge-valley profile, the Ag nanoparticle dimensions, and the material distribution in the scattering plane, were obtained by fitting the experimental zero and first order efficiency curves to simulation results of a parameterized model. The simulations were carried out adapting an in-house code based on the electromagnetic differential method, and the different material properties were taken into account by a space dependent complex dielectric constant. Information along the direction perpendicular to the scattering plane was not accessible but morphological insights were obtained combining light diffraction with atomic force microscopy. The results indicate nanoparticles with a quasi-ellipsoidal shape prolate along the ridge direction with minor and major axes of ∼12 nm and ∼21 nm, respectively.

  9. Thermoluminescent dosimetry in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lara C, A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Osorio V, M. [ISSSTE, Centro Medico Nacional 20 de Noviembre, Felix Cuevas 540, Col. del Valle, 03100 Ciudad de Mexico (Mexico); Hernandez O, O., E-mail: armando_lara_cam@yahoo.com.mx [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Ciudad de Mexico (Mexico)

    2016-10-15

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  10. Fast atom diffraction for grazing scattering of Ne atoms from a LiF(0 0 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Gravielle, M.S., E-mail: msilvia@iafe.uba.ar [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28 C1428EGA, Buenos Aires (Argentina); Departamento de Fisica, Fac. de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Schueller, A.; Winter, H. [Institut fuer Physik, Humboldt Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin-Adlershof (Germany); Miraglia, J.E. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28 C1428EGA, Buenos Aires (Argentina); Departamento de Fisica, Fac. de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2011-06-01

    Angular distributions of fast Ne atoms after grazing collisions with a LiF(0 0 1) surface under axial surface channeling conditions are experimentally and theoretically studied. We use the surface eikonal approximation to describe the quantum interference of scattered projectiles, while the atom-surface interaction is represented by means of a pairwise additive potential, including the polarization of the projectile atom. Experimental data serve as a benchmark to investigate the performance of the proposed potential model, analyzing the role played by the projectile polarization.

  11. Ex-situ characterization of synchrotron radiation induced carbon contamination on LiF window

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, P.K., E-mail: pkypay@gmail.com [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Modi, M.H. [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Swami, M.K. [Laser Biomedical Applications & Instrumentation Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Singh, P.J. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-08-15

    Highlights: • Structural characterization of contamination layer is carried out by soft x-ray reflectivity and grazing incidence x-ray diffraction. • Diffraction peaks at 2θ = 28.3° (002) shows a graphitic structures and peak at 75.3° (220) show a carbonado phase. • Out-of-plane grain sizes ∼6.05 nm and ∼2.45 nm are obtained by D.S equation for crystalline graphite and carbonado phase respectively. • Crystalline graphite G band (1556 cm{sup −1}) and disordered graphite D bands (1350 cm{sup −1}) are observed by Raman spectroscopy. • Carbon is in the form of poly carbonates (rings/chains), due to continuous exposure by radiation converted into PLCH and GLCH carbon. - Abstract: Synchrotron radiation induced carbon contaminations on optical elements is a major concern for a beamline designer. Growth mechanism of carbon deposition is not well understood. Structural characterization of radiation (3.5–11.8 eV) induced contamination layer on LiF window is carried out by soft x-ray reflectivity (SXR) and grazing incidence x-ray diffraction (GIXRD) techniques. Diffraction peaks at 2θ = 28.3° (002) shows a graphitic structures and peak at 75.3° (220) show a mixed phase (carbonado) of carbon. Out-of-plane cluster/grain sizes ∼6.05 nm and ∼2.45 nm are measured respectively for crystalline graphite and carbonado phase of carbon by Debye Scherrer equation. For elemental analysis x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy techniques are used. In Raman spectroscopy measurements the crystalline graphite G band (1556 cm{sup −1}) and disordered graphite D bands (1350 cm{sup −1}) are observed. In-plane cluster size∼ 9.62 nm was calculated by empirical relation using I{sub D} and I{sub G} ratio of Raman peaks. XPS peak at 291 eV indicates that most of the carbon is in the form of carbonate (ROCOOR’) that is polymerizing in form of rings/chains and converted into polymer like (PLCH) and graphitic like hydrogenated (GLCH) carbon due

  12. Junctional adhesion molecule 2 mediates the interaction between hatched blastocyst and luminal epithelium: induction by progesterone and LIF.

    Directory of Open Access Journals (Sweden)

    Ren-Wei Su

    Full Text Available BACKGROUND: Junctional adhesion molecule 2 (Jam2 is a member of the JAM superfamily. JAMs are localized at intercellular contacts and participated in the assembly and maintenance of junctions, and control of cell permeability. Because Jam2 is highly expressed in the luminal epithelium on day 4 of pregnancy, this study was to determine whether Jam2 plays a role in uterine receptivity and blastocyst attachment in mouse uterus. METHODOLOGY/PRINCIPAL FINDINGS: Jam2 is highly expressed in the uterine luminal epithelium on days 3 and 4 of pregnancy. Progesterone induces Jam2 expression in ovariectomized mice, which is blocked by progesterone antagonist RU486. Jam2 expression on day 4 of pregnancy is also inhibited by RU486 treatment. Leukemia inhibitory factor (LIF up-regulates Jam2 protein in isolated luminal epithelium from day 4 uterus, which is blocked by S3I-201, a cell-permeable inhibitor for Stat3 phosphorylation. Under adhesion assay, recombinant Jam2 protein increases the rate of blastocyst adhesion. Both soluble recombinant Jam2 and Jam3 can reverse this process. CONCLUSION: Jam2 is highly expressed in the luminal epithelium of receptive uterus and up-regulated by progesterone and LIF via tyrosine phosphorylation of Stat3. Jam2 may play a role in the interaction between hatched blastocyst and receptive uterus.

  13. Magnetic flux and heat losses by diffusive, advective, and Nernst effects in MagLIF-like plasma

    Energy Technology Data Exchange (ETDEWEB)

    Velikovich, A. L., E-mail: sasha.velikovich@nrl.navy.mil; Giuliani, J. L., E-mail: sasha.velikovich@nrl.navy.mil [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Zalesak, S. T. [Berkeley Research Associates, Beltsville, MD 20705 (United States)

    2014-12-15

    The MagLIF approach to inertial confinement fusion involves subsonic/isobaric compression and heating of a DT plasma with frozen-in magnetic flux by a heavy cylindrical liner. The losses of heat and magnetic flux from the plasma to the liner are thereby determined by plasma advection and gradient-driven transport processes, such as thermal conductivity, magnetic field diffusion and thermomagnetic effects. Theoretical analysis based on obtaining exact self-similar solutions of the classical collisional Braginskii's plasma transport equations in one dimension demonstrates that the heat loss from the hot plasma to the cold liner is dominated by the transverse heat conduction and advection, and the corresponding loss of magnetic flux is dominated by advection and the Nernst effect. For a large electron Hall parameter ω{sub e}τ{sub e} effective diffusion coefficients determining the losses of heat and magnetic flux are both shown to decrease with ω{sub e}τ{sub e} as does the Bohm diffusion coefficient, which is commonly associated with low collisionality and two-dimensional transport. This family of exact solutions can be used for verification of codes that model the MagLIF plasma dynamics.

  14. Laser Induced Fluorescence (LIF) Data for Neutral Argon (ArI) in a Large Scale Helicon Plasm

    Science.gov (United States)

    Kelly, Ralph; Gilmore, Mark; Meany, Kevin; Zhang, Yue; Desjardins, Tiffany

    2016-10-01

    When neutral and ion densities are spatially non-uniform, neutral-ion collisions can exert a torque on a magnetized plasma column via the FxB force, where F is the force exerted on ions by neutrals. This FxB force may have a significant effect on the dynamics of plasma instabilities and flows. In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, an Ar I Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable solid state laser. The laser will pumps the metastable (2P3/2 0) 4s level to the (2P1/2 0) 4p level using 696. 7352 nm light, and fluorescence radiation from decay to the (2P1/2 0) 4s level at 772. 6333 nm is observed. The system design and initial data will be presented.

  15. Development of azimuthally correlated instabilities for MagLIF seeded by electro-thermal and material strength effects

    Science.gov (United States)

    Pecover, James; Weinwurm, Marcus; Chittenden, Jeremy

    2014-10-01

    Magnetized liner inertial fusion (MagLIF) is a promising route to controlled thermonuclear fusion. The concept involves magnetically imploding a metal liner; a key limitation of such systems is the magneto-Rayleigh-Taylor (MRT) instability. MagLIF relevant liner implosions carried out at Sandia showed high amplitude MRT growth. 3D simulations with our MHD code Gorgon have shown that azimuthal correlation required to explain this can be contributed to by early time effects the electro-thermal instability (ETI) and an ``electro-choric instability'' (ECI). Shear forces can damp short wavelength perturbations while the liner remains solid, potentially setting axial wavelengths for the ETI and ECI. We can now model shear stresses in solids with Gorgon using a Johnson-Cook strength model and a bulk modulus calculated from the FEOS equation of state. Gorgon results with the strength model are compared to results from the shock hydrodynamics code iSALE. Results for liners show elongation of perturbations at the outer edge relative to the case without strength. We present results showing the model applied to liner implosions with axial magnetic fields of 0 T and 10 T.

  16. Magnetic flux and heat losses by diffusive, advective, and Nernst effects in MagLIF-like plasma

    Science.gov (United States)

    Velikovich, A. L.; Giuliani, J. L.; Zalesak, S. T.

    2014-12-01

    The MagLIF approach to inertial confinement fusion involves subsonic/isobaric compression and heating of a DT plasma with frozen-in magnetic flux by a heavy cylindrical liner. The losses of heat and magnetic flux from the plasma to the liner are thereby determined by plasma advection and gradient-driven transport processes, such as thermal conductivity, magnetic field diffusion and thermomagnetic effects. Theoretical analysis based on obtaining exact self-similar solutions of the classical collisional Braginskii's plasma transport equations in one dimension demonstrates that the heat loss from the hot plasma to the cold liner is dominated by the transverse heat conduction and advection, and the corresponding loss of magnetic flux is dominated by advection and the Nernst effect. For a large electron Hall parameter ωeτe effective diffusion coefficients determining the losses of heat and magnetic flux are both shown to decrease with ωeτe as does the Bohm diffusion coefficient, which is commonly associated with low collisionality and two-dimensional transport. This family of exact solutions can be used for verification of codes that model the MagLIF plasma dynamics.

  17. The effect of electro-thermal and electro-choric instabilities and material strength on MagLIF liner stability

    Science.gov (United States)

    Pecover, James; Chittenden, Jeremy

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising route to controlled thermonuclear fusion. The concept involves magnetically imploding a metal liner containing fuel with an azimuthal magnetic field (Bz) ; a key limitation of such systems is the magneto-Rayleigh-Taylor (MRT) instability. MagLIF relevant liner implosions with Bz = 0 carried out at SNL showed high amplitude MRT growth; we present a quantitative comparison between experimental results and 3D results from our MHD code Gorgon, demonstrating closer agreement for the MRT properties with the inclusion of electro-thermal and electro-choric instabilities (ETI and ECI) and material strength. The ETI and ECI result in early time azimuthally correlated structures which provide a seed for the MRT. Material strength increases the ETI amplitude due to positive feedback during the solid phase of the liner. Similar liner implosions with Bz exhibited a re-orientation of the MRT into helical structures, which are yet to be reproduced by simulations without an artificial helical initialisation. Our 3D Gorgon results with Bz show helices prior to vapourisation; these occur at initially positive angles before changing sign, tending to zero later in time. This angle does not follow the relative magnitudes of Bz and Bθ as would be expected for the MRT. The angle instead follows the ratio of axial and azimuthal currents (induced by compression or rarefaction of the initial Bz) , indicating an electro-thermal origin.

  18. The effect of cytoplasmic regions of LIF receptor on activating MAPK p42/44 in HL-60 cell

    Institute of Scientific and Technical Information of China (English)

    LIU Hou-qi; SHAN Ji-kuan; TANG Shu-ping; LIU Shan-rong; JI Kai-hong

    2001-01-01

    Objective: To study the relation between the cytoplasmic region of each subunit of leukemia inhibitory factor (LIF) receptor and mitogen-activated protein kinase (MAPK) in human leukemia line HL-60 for studying the mechanism of leukemia cell proliferation disorder. Methods: We prepared the chimerical receptor with exchanged cytoplasmic domain (190/130,130/190), expressed it on the membrane of HL-60, and then bound LIF with the wild type receptor competitively. The cytoplasmic region homodimerization (190cyt- 190cyt, 130cyt- 130cyt) initiated intracellular signal transduction, cell proliferation and differentiation. MAPK phosphorylation level was observed by means of immunoblotting and immunobiochemistry. Results: Higher level ofMAPK p42/p44 phosphorylation (Thr202Tyr204) and faster cell proliferation were determined in group 190/130 compared with the wild type receptor. Those in group 130/190 were lower than the others. Conclusion: The cytoplasmic domain ofgpl30 involves in the induction of MAPK activation and the cell proliferation of HL-60.

  19. Vaginally administered PEGylated LIF antagonist blocked embryo implantation and eliminated non-target effects on bone in mice.

    Directory of Open Access Journals (Sweden)

    Ellen Menkhorst

    Full Text Available Female-controlled contraception/HIV prevention is critical to address health issues associated with gender inequality. Therefore, a contraceptive which can be administered in tandem with a microbicide to inhibit sexually transmitted infections, is desirable. Uterine leukemia inhibitory factor (LIF is obligatory for blastocyst implantation in mice and associated with infertility in women. We aimed to determine whether a PEGylated LIF inhibitor (PEGLA was an effective contraceptive following vaginal delivery and to identify non-uterine targets of PEGLA in mice.Vaginally-applied (125I-PEGLA accumulated in blood more slowly (30 min vs 10 min and showed reduced tissue and blood retention (24 h vs 96 h compared to intraperitoneal injection in mice. Vaginally-applied PEGLA blocked implantation. PEGLA administered by intraperitoneal injection inhibited bone remodelling whereas vaginally-applied PEGLA had no effect on bone. Further, PEGLA had no effect in an animal model of multiple sclerosis, experimental auto-immune encephalomyelitis, suggesting PEGLA cannot target the central nervous system.Vaginally-administered PEGLA is a promising non-hormonal contraceptive, one which could be delivered alone, or in tandem with a microbicide. Vaginal application reduced the total dose of PEGLA required to block implantation and eliminated the systemic effect on bone, showing the vagina is a promising site of administration for larger drugs which target organs within the reproductive tract.

  20. Progesterone is essential for protecting against LPS-induced pregnancy loss. LIF as a potential mediator of the anti-inflammatory effect of progesterone.

    Directory of Open Access Journals (Sweden)

    Julieta Aisemberg

    Full Text Available Lipopolysaccharide (LPS administration to mice on day 7 of gestation led to 100% embryonic resorption after 24 h. In this model, nitric oxide is fundamental for the resorption process. Progesterone may be responsible, at least in part, for a Th2 switch in the feto-maternal interface, inducing active immune tolerance against fetal antigens. Th2 cells promote the development of T cells, producing leukemia inhibitory factor (LIF, which seems to be important due to its immunomodulatory action during early pregnancy. Our aim was to evaluate the involvement of progesterone in the mechanism of LPS-induced embryonic resorption, and whether LIF can mediate hormonal action. Using in vivo and in vitro models, we provide evidence that circulating progesterone is an important component of the process by which infection causes embryonic resorption in mice. Also, LIF seems to be a mediator of the progesterone effect under inflammatory conditions. We found that serum progesterone fell to very low levels after 24 h of LPS exposure. Moreover, progesterone supplementation prevented embryonic resorption and LPS-induced increase of uterine nitric oxide levels in vivo. Results show that LPS diminished the expression of the nuclear progesterone receptor in the uterus after 6 and 12 h of treatment. We investigated the expression of LIF in uterine tissue from pregnant mice and found that progesterone up-regulates LIF mRNA expression in vitro. We observed that LIF was able to modulate the levels of nitric oxide induced by LPS in vitro, suggesting that it could be a potential mediator of the inflammatory action of progesterone. Our observations support the view that progesterone plays a critical role in a successful pregnancy as an anti-inflammatory agent, and that it could have possible therapeutic applications in the prevention of early reproductive failure associated with inflammatory disorders.

  1. Winckelmannist Marxi ja Engelsini : kultuuriline sallivus historismi ja klassitsismi esteetiliste suhete probleemina : Lif̧itsi juhtum / Mart Kivimäe

    Index Scriptorium Estoniae

    Kivimäe, Mart, 1951-

    2008-01-01

    Käsitletakse neomarksistliku ajaloopoliitika olulist esteetilist mõõdet - võitlust ajaloolise relativismi vastu modernses kunsti- ja kultuurikäsitluses. Keskpunktiks on Mihhail Lif̧itsi (1905-1983)"klassitsistlikult" põhjendatud marksism ja Winckelmanni retseptsioon ning selle esteetilised ja poliitilised kontekstid. Sotsialismi paradokse kehastava Lif̧itsi Winckelmanni-pilt oli üles ehitatud Marxi-kesksele allikabaasile, püüdes marksismi tähe all elustada klassitsismi, oli ka nõukogude hegelianismi esindaja koos György Luk{u00E1csega (1885-1971)

  2. Winckelmannist Marxi ja Engelsini : kultuuriline sallivus historismi ja klassitsismi esteetiliste suhete probleemina : Lif̧itsi juhtum / Mart Kivimäe

    Index Scriptorium Estoniae

    Kivimäe, Mart, 1951-

    2008-01-01

    Käsitletakse neomarksistliku ajaloopoliitika olulist esteetilist mõõdet - võitlust ajaloolise relativismi vastu modernses kunsti- ja kultuurikäsitluses. Keskpunktiks on Mihhail Lif̧itsi (1905-1983)"klassitsistlikult" põhjendatud marksism ja Winckelmanni retseptsioon ning selle esteetilised ja poliitilised kontekstid. Sotsialismi paradokse kehastava Lif̧itsi Winckelmanni-pilt oli üles ehitatud Marxi-kesksele allikabaasile, püüdes marksismi tähe all elustada klassitsismi, oli ka nõukogude hegelianismi esindaja koos György Luk{u00E1csega (1885-1971)

  3. Elastic wave from fast heavy ion irradiation on solids

    CERN Document Server

    Kambara, T; Kanai, Y; Kojima, T M; Nanai, Y; Yoneda, A; Yamazaki, Y

    2002-01-01

    To study the time-dependent mechanical effects of fast heavy ion irradiations, we have irradiated various solids by a short-bunch beam of 95 MeV/u Ar ions and observed elastic waves generated in the bulk. The irradiated targets were square-shaped plates of poly-crystals of metals (Al and Cu), invar alloy, ceramic (Al sub 2 O sub 3), fused silica (SiO sub 2) and single crystals of KC1 and LiF with a thickness of 10 mm. The beam was incident perpendicular to the surface and all ions were stopped in the target. Two piezo-electric ultrasonic sensors were attached to the surface of the target and detected the elastic waves. The elastic waveforms as well as the time structure and intensity of the beam bunch were recorded for each shot of a beam bunch. The sensor placed opposite to the beam spot recorded a clear waveform of the longitudinal wave across the material, except for the invar and fused silica targets. From its propagation time along with the sound velocity and the thickness of the target, the depth of the...

  4. Elastic wave from fast heavy ion irradiation on solids

    Science.gov (United States)

    Kambara, T.; Kageyama, K.; Kanai, Y.; Kojima, T. M.; Nanai, Y.; Yoneda, A.; Yamazaki, Y.

    2002-06-01

    To study the time-dependent mechanical effects of fast heavy ion irradiations, we have irradiated various solids by a short-bunch beam of 95 MeV/u Ar ions and observed elastic waves generated in the bulk. The irradiated targets were square-shaped plates of poly-crystals of metals (Al and Cu), invar alloy, ceramic (Al 2O 3), fused silica (SiO 2) and single crystals of KC1 and LiF with a thickness of 10 mm. The beam was incident perpendicular to the surface and all ions were stopped in the target. Two piezo-electric ultrasonic sensors were attached to the surface of the target and detected the elastic waves. The elastic waveforms as well as the time structure and intensity of the beam bunch were recorded for each shot of a beam bunch. The sensor placed opposite to the beam spot recorded a clear waveform of the longitudinal wave across the material, except for the invar and fused silica targets. From its propagation time along with the sound velocity and the thickness of the target, the depth of the wave source was estimated. The result was compared with ion ranges calculated for these materials by TRIM code.

  5. Development and implementation of an anthropomorphic pediatric spine phantom for the assessment of craniospinal irradiation procedures in proton therapy

    Directory of Open Access Journals (Sweden)

    Dana J Lewis

    2014-03-01

    Full Text Available Purpose: To design an anthropomorphic pediatric spine phantom for use in the evaluation of proton therapy facilities for clinical trial participation by the Imaging and Radiation Oncology Core (IROC Houston QA Center (formerly RPC.Methods: This phantom was designed to perform an end-to-end audit of the proton spine treatment process, including simulation, dose calculation by the treatment planning system (TPS, and proton treatment delivery. The design incorporated materials simulating the thoracic spinal column of a pediatric patient, along with two thermoluminescent dosimeter (TLD-100 capsules and radiochromic film embedded in the phantom for dose evaluation. Fourteen potential materials were tested to determine relative proton stopping power (RSP and Hounsfield unit (HU values. Each material was CT scanned at 120 kVp, and the RSP was obtained from depth ionization scans using the Zebra multi-layer ion chamber (MLIC at two energies: 160 MeV and 250 MeV. To determine tissue equivalency, the measured RSP for each material was compared to the RSP calculated by the Eclipse TPS for a given HU.Results: The materials selected as bone, tissue, and cartilage substitutes were Techron HPV Bearing Grade (Boedeker Plastics, Inc., solid water, and blue water, respectively. The RSP values did not differ by more than 1.8% between the two energies. The measured RSP for each selected material agreed with the RSP calculated by the Eclipse TPS within 1.2%.Conclusion: An anthropomorphic pediatric proton spine phantom was designed to evaluate proton therapy delivery. The inclusion of multiple tissue substitutes increases heterogeneity and the level of difficulty for institutions to successfully treat the phantom. The following attributes will be evaluated: absolute dose agreement, distal range, field width, junction match and right/left dose profile alignment. The phantom will be tested at several institutions using a 5% dose agreement criterion, and a 5%/3mm gamma

  6. Neutron Fading Characteristics of Copper Doped Lithium Fluoride (LiF: MCP) Thermoluminescent Dosimeters (TLDs)

    Science.gov (United States)

    2008-05-21

    particular type of radiation and has the SI units of Sieverts (Sv) or traditional units of Roentgen Equivalent Man ( rem ). It is calculated by multiplying...dosimeter was irradiated to 50 mSv (5 Rem ). The 10.31 pC 194.5 ROil 689.6 ROl2 8285. ROl3 1040. ROl4 ECC Ra= 1 pA 20 .. 43 44 .. 57 58- 75 76- 92...Methods Laboratory SDDML in Beijing, China shows a sub linear response at about 12 Gy.[73] Italian scientists have effectively measured the dose response

  7. Radio-photoluminescence of highly irradiated LiF:Mg,Ti and LiF:Mg,Cu,P detectors

    CERN Document Server

    Mrozik, Anna; Marczewska, Barbara; Obryk, Barbara; Hodyr, Krzysztof; Gieszczyk, Wojciech

    2014-01-01

    The radio-photoluminescent (RPL) characteristics of LiF:Mg,Ti (MTS) and LiF:Mg,Cu,P (MCP) thermoluminescent detectors, routinely used in radiation protection dosimetry, were investigated after irradiation with ultra-high electron doses ranging up to 1 MGy. The photoluminescence of both types of LiF detectors was stimulated by a blue light (460 nm) and measured within a spectral window around 530 nm. The RPL dose response was found to be linear up to 50 kGy and sublinear in the range of 50 kGy to 1 MGy for MCP detectors and linear up to 3 kGy and next sublinear in the range from 5 kGy to 1 MGy for MTS detectors. For both type of LiF detectors RPL signal is saturated for doses higher than 100 kGy. The observed differences between MCP and MTS may suggest, that the RPL effect in LiF is not entirely governed by intrinsic defects (F2 and F3+ centers), but impurities may also have a significant influence. Due to the non-destructive character of the RPL measurement, it is suggested to apply combined RPL/TL readouts, ...

  8. Design study of multi-imaging plate system for BNCT irradiation field at Kyoto university reactor.

    Science.gov (United States)

    Tanaka, Kenichi; Sakurai, Yoshinori; Kajimoto, Tsuyoshi; Tanaka, Hiroki; Takata, Takushi; Endo, Satoru

    2016-09-01

    The converter configuration for a multi-imaging plate system was investigated for the application of quality assurance in the irradiation field profile for boron neutron capture therapy. This was performed by the simulation calculation using the PHITS code in the fields at the Heavy Water Neutron Irradiation Facility of Kyoto University Reactor. The converter constituents investigated were carbon for gamma rays, and polyethylene with and without LiF at varied (6)Li concentration for thermal, epithermal, and fast neutrons. Consequently, potential combinations of the converters were found for two components, gamma rays and thermal neutrons, for the standard thermal neutron mode and three components of gamma rays, epithermal neutrons, and thermal or fast neutrons, for the standard mixed or epithermal neutron modes, respectively.

  9. Selective irradiation of radicals for biomedical treatment using vacuum ultraviolet light from an excimer lamp

    Science.gov (United States)

    Ono, Ryo; Tokumitsu, Yusuke; Zen, Shungo; Yonemori, Seiya

    2014-10-01

    In plasma medicine, radicals are considered to play important roles. However, the medical effect of each radical, such as OH and O, is unknown. To examine the effect of each radical, selective production of radicals is needed. We developed selective production of radicals for biomedical treatment using a vacuum ultraviolet (VUV) light emitted from an excimer lamp. Selective irradiation of OH radicals can be achieved by irradiating the 172-nm VUV light from a Xe2 excimer lamp to a humid helium flow in a quartz tube. The water molecules are strongly photodissociated by the VUV light to produce OH radicals. A photochemical simulation for the selective OH production is developed to calculate the OH density. The calculated OH density is compared with OH density measured using laser-induced fluorescence (LIF). Selective production of other radicals than OH is also discussed.

  10. Oxygen imaging at the sediment-water interface using lifetime-based laser induced fluorescence (tau LIF) of nano-sized particles

    DEFF Research Database (Denmark)

    Murniati, E.; Gross, D.; Herlina, H.

    2016-01-01

    Most applications of laser induced fluorescence (LIF) for dissolved oxygen (DO) imaging in flowing water are based on luminescence intensity measurements of a dissolved indicator. A major limitation for applying the technique in the bottom boundary layer (BBL) is the sorption of the luminescent dye...

  11. Establishment of LIF-dependent human iPS cells closely related to basic FGF-dependent authentic iPS cells.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hirai

    Full Text Available Human induced pluripotent stem cells (iPSCs can be divided into a leukemia inhibitory factor (LIF-dependent naïve type and a basic fibroblast growth factor (bFGF-dependent primed type. Although the former are more undifferentiated than the latter, they require signal transduction inhibitors and sustained expression of the transgenes used for iPSC production. We used a transcriptionally enhanced version of OCT4 to establish LIF-dependent human iPSCs without the use of inhibitors and sustained transgene expression. These cells belong to the primed type of pluripotent stem cell, similar to bFGF-dependent iPSCs. Thus, the particular cytokine required for iPSC production does not necessarily define stem cell phenotypes as previously thought. It is likely that the bFGF and LIF signaling pathways converge on unidentified OCT4 target genes. These findings suggest that our LIF-dependent human iPSCs could provide a novel model to investigate the role of cytokine signaling in cellular reprogramming.

  12. High performance planar p-i-n perovskite solar cells with crown-ether functionalized fullerene and LiF as double cathode buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaodong; Zhou, Yi, E-mail: yizhou@suda.edu.cn, E-mail: songbo@suda.edu.cn, E-mail: liyf@iccas.ac.cn; Song, Bo, E-mail: yizhou@suda.edu.cn, E-mail: songbo@suda.edu.cn, E-mail: liyf@iccas.ac.cn [Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Lei, Ming [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Li, Yongfang, E-mail: yizhou@suda.edu.cn, E-mail: songbo@suda.edu.cn, E-mail: liyf@iccas.ac.cn [Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-08-10

    Double cathode buffer layers (CBLs) composed of fullerene derivative functionalized with a crown-ether end group in its side chain (denoted as PCBC) and a LiF layer were introduced between the PCBM acceptor layer and the top cathode in planar p-i-n perovskite solar cells (pero-SCs) based on CH{sub 3}NH{sub 3}PbI{sub 3−X}Cl{sub X}. The devices with the PCBC/LiF double CBLs showed significant improvements in power conversion efficiency (PCE) and long-term stability when compared to the device with LiF single CBL. Through optimizing the spin-coating speed of PCBC, a maximum PCE of 15.53% has been achieved, which is approximately 15% higher than that of the device with single LiF CBL. The remarkable improvement in PCE can be attributed to the formation of a better ohmic contact in the CBL between PCBC and LiF/Al electrode arising from the dipole moment of PCBC, leading to the enhanced fill factor and short-circuit current density (J{sub sc}). Besides the PCE, the long-term stability of the devices with PCBC interlayer is also superior to that of the device with LiF single CBL, which is due to the more effective protection for the perovskite/PCBM interface.

  13. Food irradiation makes progress

    Energy Technology Data Exchange (ETDEWEB)

    Kooij, J. van (Joint FAO/IAEA Div. of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Vienna (Austria))

    1984-06-01

    In the past fifteen years, food irradiation processing policies and programmes have been developed both by a number of individual countries, and through projects supported by FAO, IAEA and WHO. These aim at achieving general acceptance and practical implementation of food irradiation through rigorous investigations of its wholesomeness, technological and economic feasibility, and efforts to achieve the unimpeded movement of irradiated foods in international trade. Food irradiation processing has many uses.

  14. Food irradiation in China

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, L.

    1986-08-01

    The paper concerns food irradiation in The People's Republic of China. Its use is envisaged to prolong storage times and to improve the quality of specific foodstuffs. Commercialisation in China, demonstration plants, seasonal shortages and losses, Shanghai irradiation centre, health and safety approval, prospects for wider applications and worldwide use of food irradiation, are all discussed.

  15. Spike Pattern Structure Influences Synaptic Efficacy Variability under STDP and Synaptic Homeostasis. II: Spike Shuffling Methods on LIF Networks

    Science.gov (United States)

    Bi, Zedong; Zhou, Changsong

    2016-01-01

    Synapses may undergo variable changes during plasticity because of the variability of spike patterns such as temporal stochasticity and spatial randomness. Here, we call the variability of synaptic weight changes during plasticity to be efficacy variability. In this paper, we investigate how four aspects of spike pattern statistics (i.e., synchronous firing, burstiness/regularity, heterogeneity of rates and heterogeneity of cross-correlations) influence the efficacy variability under pair-wise additive spike-timing dependent plasticity (STDP) and synaptic homeostasis (the mean strength of plastic synapses into a neuron is bounded), by implementing spike shuffling methods onto spike patterns self-organized by a network of excitatory and inhibitory leaky integrate-and-fire (LIF) neurons. With the increase of the decay time scale of the inhibitory synaptic currents, the LIF network undergoes a transition from asynchronous state to weak synchronous state and then to synchronous bursting state. We first shuffle these spike patterns using a variety of methods, each designed to evidently change a specific pattern statistics; and then investigate the change of efficacy variability of the synapses under STDP and synaptic homeostasis, when the neurons in the network fire according to the spike patterns before and after being treated by a shuffling method. In this way, we can understand how the change of pattern statistics may cause the change of efficacy variability. Our results are consistent with those of our previous study which implements spike-generating models on converging motifs. We also find that burstiness/regularity is important to determine the efficacy variability under asynchronous states, while heterogeneity of cross-correlations is the main factor to cause efficacy variability when the network moves into synchronous bursting states (the states observed in epilepsy). PMID:27555816

  16. Laser propagation through full-scale, high-gain MagLIF gas pipes using the NIF

    Science.gov (United States)

    Pollock, Bradley; Sefkow, Adam; Goyon, Clement; Strozzi, David; Khan, Shahab; Rosen, Mordy; Campbell, Mike; Logan, Grant; Peterson, Kyle; Moody, John

    2016-10-01

    The first relevant measurements of laser propagation through surrogate high-gain MagLIF gas pipe targets at full scale have been performed at the NIF, using 30 kJ of laser drive from one quad in a 10 ns pulse at an intensity of 2e14 W/cm2. The unmagnetized pipe is filled with 1 atm of 99%/1% neopentane/Ar, and uses an entrance window of 0.75 um polyimide and an exit window of 0.3 um of Ta backed with 5 um of polyimide. Side-on x-ray emission from the plasma is imaged through the 100 um-thick epoxy wall onto a framing camera at four times during the drive, and is in excellent agreement with pre-shot HYDRA radiation-hydrodynamics modeling. X-ray emission from the Ta exit plane is imaged onto a streak camera to determine the timing and intensity of the laser burning through the pipe, and the Ar emission from the center of the pipe is spectrally- and temporally-resolved to determine the plasma electron temperature. Backscatter is measured throughout the laser drive, and is found to be of significance only when the laser reaches the Ta exit plane and produces SBS. These first results in unmagnetized surrogate gas fills are encouraging since they demonstrate sufficient laser energy absorption and low LPI losses within high-density long-scale-length plasmas for proposed high-gain MagLIF target designs. We will discuss plans to magnetize targets filled with high-density DT gas in future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  17. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    Directory of Open Access Journals (Sweden)

    H. Fuchs

    2012-07-01

    Full Text Available During recent field campaigns, hydroxyl radical (OH concentrations that were measured by laser-induced fluorescence (LIF were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK, methacrolein (MACR and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD, China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS. Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s−1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03 × 106 cm−3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30–40% (median larger than those by DOAS after MVK (20 ppbv and

  18. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    Science.gov (United States)

    Fuchs, H.; Dorn, H.-P.; Bachner, M.; Bohn, B.; Brauers, T.; Gomm, S.; Hofzumahaus, A.; Holland, F.; Nehr, S.; Rohrer, F.; Tillmann, R.; Wahner, A.

    2012-07-01

    During recent field campaigns, hydroxyl radical (OH) concentrations that were measured by laser-induced fluorescence (LIF) were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK), methacrolein (MACR) and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD), China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS). Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s-1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points) yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03) × 106 cm-3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30-40% (median) larger than those by DOAS after MVK (20 ppbv) and toluene (90 ppbv) had been added. However, this discrepancy has a

  19. Beryllium liner implosion experiments on the Z accelerator in preparation for Magnetized Liner Inertial Fusion (MagLIF)*

    Science.gov (United States)

    McBride, Ryan D.

    2012-10-01

    Magnetized Liner Inertial Fusion (MagLIF) [1] is a concept that involves using a pulsed electrical current to implode an initially-solid, cylindrical metal tube (liner) filled with preheated and magnetized fusion fuel. One- and two-dimensional simulations predict that if sufficient liner integrity can be maintained throughout the implosion, then significant fusion yield (>100 kJ) is possible on the 25-MA, 100-ns Z accelerator. The greatest threat to the liner integrity is the Magneto-Rayleigh-Taylor (MRT) instability, which first develops on the outer liner surface, and then works its way inward toward the inner surface throughout the implosion. Two-dimensional simulations predict that a thick liner, with Router/δR=6, should be robust enough to keep the MRT instability from overly disrupting the fusion burn at stagnation. This talk will present the first experiments designed to study a thick, MagLIF-relevant liner implosion through to stagnation on Z [2]. The use of beryllium for the liner material enabled us to obtain penetrating monochromatic (6151±0.5 eV) radiographs that reveal information about the entire volume of the imploding liner. This talk will also discuss experiments that investigated Z's pulse-shaping capabilities to either shock- or shocklessly-compress the imploding liners [3], as well as our most recent experiments that used 2-micron-thick aluminum sleeves to provide high-contrast tracers for the positions and states of the inner surfaces of the imploding beryllium liners. The radiography data to be presented provide stringent constraints on the simulation tools used by the broader high energy density physics and inertial confinement fusion communities, where quantitative areal density measurements, particularly of convergent fusion targets, are relatively scarce. We will also present power-flow tests of the MagLIF load hardware as well as new micro-B-dot measurements of the azimuthal drive magnetic field that penetrates the initially vacuum

  20. The European multicenter trial on the safety and efficacy of guided oblique lumbar interbody fusion (GO-LIF

    Directory of Open Access Journals (Sweden)

    Birkenmaier Christof

    2010-09-01

    Full Text Available Abstract Background Because of the implant-related problems with pedicle screw-based spinal instrumentations, other types of fixation have been tried in spinal arthrodesis. One such technique is the direct trans-pedicular, trans-discal screw fixation, pioneered by Grob for spondylolisthesis. The newly developed GO-LIF procedure expands the scope of the Grob technique in several important ways and adds security by means of robotic-assisted navigation. This is the first clinical trial on the GO-LIF procedure and it will assess safety and efficacy. Methods/Design Multicentric prospective study with n = 40 patients to undergo single level instrumented spinal arthrodesis of the lumbar or the lumbosacral spine, based on a diagnosis of: painful disc degeneration, painful erosive osteochondrosis, segmental instability, recurrent disc herniation, spinal canal stenosis or foraminal stenosis. The primary target criteria with regards to safety are: The number, severity and cause of intra- and perioperative complications. The number of significant penetrations of the cortical layer of the vertebral body by the implant as recognized on postoperative CT. The primary target parameters with regards to feasibility are: Performance of the procedure according to the preoperative plan. The planned follow-up is 12 months and the following scores will be evaluated as secondary target parameters with regards to clinical improvement: VAS back pain, VAS leg pain, Oswestry Disability Index, short form - 12 health questionnaire and the Swiss spinal stenosis questionnaire for patients with spinal claudication. The secondary parameters with regards to construct stability are visible fusion or lack thereof and signs of implant loosening, implant migration or pseudarthrosis on plain and functional radiographs. Discussion This trial will for the first time assess the safety and efficacy of guided oblique lumbar interbody fusion. There is no control group, but the results, the

  1. Evaluation of machine learning algorithms for classification of primary biological aerosol using a new UV-LIF spectrometer

    Science.gov (United States)

    Ruske, Simon; Topping, David O.; Foot, Virginia E.; Kaye, Paul H.; Stanley, Warren R.; Crawford, Ian; Morse, Andrew P.; Gallagher, Martin W.

    2017-03-01

    Characterisation of bioaerosols has important implications within environment and public health sectors. Recent developments in ultraviolet light-induced fluorescence (UV-LIF) detectors such as the Wideband Integrated Bioaerosol Spectrometer (WIBS) and the newly introduced Multiparameter Bioaerosol Spectrometer (MBS) have allowed for the real-time collection of fluorescence, size and morphology measurements for the purpose of discriminating between bacteria, fungal spores and pollen.This new generation of instruments has enabled ever larger data sets to be compiled with the aim of studying more complex environments. In real world data sets, particularly those from an urban environment, the population may be dominated by non-biological fluorescent interferents, bringing into question the accuracy of measurements of quantities such as concentrations. It is therefore imperative that we validate the performance of different algorithms which can be used for the task of classification.For unsupervised learning we tested hierarchical agglomerative clustering with various different linkages. For supervised learning, 11 methods were tested, including decision trees, ensemble methods (random forests, gradient boosting and AdaBoost), two implementations for support vector machines (libsvm and liblinear) and Gaussian methods (Gaussian naïve Bayesian, quadratic and linear discriminant analysis, the k-nearest neighbours algorithm and artificial neural networks).The methods were applied to two different data sets produced using the new MBS, which provides multichannel UV-LIF fluorescence signatures for single airborne biological particles. The first data set contained mixed PSLs and the second contained a variety of laboratory-generated aerosol.Clustering in general performs slightly worse than the supervised learning methods, correctly classifying, at best, only 67. 6 and 91. 1 % for the two data sets respectively. For supervised learning the gradient boosting algorithm was

  2. Modelling property changes in graphite irradiated at changing irradiation temperature

    CSIR Research Space (South Africa)

    Kok, S

    2011-01-01

    Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

  3. Tunable (0. 86--1. mu. ) cw room-temperature laser utilizing F/sup +//sub 2/ color centers in an LiF crystal

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, Y.L.; Kirpichnikov, A.V.; Kruglov, S.N.; Marennikov, S.I.

    1980-05-01

    The development of a cw room-temperature laser tunable in the 0.86--1 ..mu.. range, utilizing F/sup +//sub 2/ color centers in an LiF crystal, is reported. When pumped by a krypton laser (lambda=0.647 mm), its lasing threshold was 400 mW. A method of regenerating centers using excimer laser radiation (lambda=310 nm) was tried.

  4. Selenate Enhances STAT3 Transcriptional Activity in Endothelial Cells: Differential Actions of Selenate and Selenite on LIF Cytokine Signaling and Cell Viability

    OpenAIRE

    Alturkmani, Hani J; Zgheib, Carlos; Zouein, Fouad A.; Alshaaer, Nour Eddin F.; Kurdi, Mazen; Booz, George W.

    2012-01-01

    Sodium selenate may have utility in treating Alzheimer’s disease and diabetes; however, its impact on the associated proinflammatory cytokine signaling of endothelial cells has not been investigated. We report that treatment of human microvascular endothelial cells with sodium selenate at a pharmacological dose (100 μM) enhanced tyrosine phosphorylation of nuclear STAT3 on Y705 in response to IL-6-type cytokine, leukemia inhibitory factor (LIF), indicative of enhanced STAT3 activity. Accordin...

  5. Upgrade of the POLDI diffractometer with a ZnS(Ag)/6LiF scintillation detector read out with WLS fibers coupled to SiPMs

    OpenAIRE

    Mosset, J. -B.; Stoykov, A.; Davydov, V.; Hildebrandt, M.; Van Swygenhoven, H.; W. Wagner

    2013-01-01

    A thermal neutron detector based on ZnS(Ag)/6LiF scintillator, wavelength-shifting fibers (WLS) and silicon photomultipliers (SiPM) is under development at the Paul Scherrer Institute (PSI) for upgrading the POLDI instrument, a pulse-overlap diffractometer. The design of the detector is outlined, and the measurements performed on a single channel prototype are presented. An innovative signal processing system based on a photon counting approach is under development. Its principle of operation...

  6. Characteristics of a thermal neutrons scintillation detector with the [ZnS(Ag)+$^6$LiF] at different conditions of measurements

    OpenAIRE

    Alekseenko, V. V.; Barabanov, I. R.; Etezov, R. A.; Gavrilyuk, Yu. M.; Gangapshev, A. M.; Gezhaev, A. M.; Kazalov, V. V.; Khokonov, A. Kh.; V.V. Kuzminov; Panasenko, S. I.; Ratkevich, S. S.

    2015-01-01

    A construction of a thermal neutron testing detector with a thin [ZnS(Ag)+$^6$LiF] scintillator is described. Results of an investigation of sources of the detector pulse origin and the pulse features in a ground and underground conditions are presented. Measurements of the scintillator own background, registration efficiency and a neutron flux at different objects of the BNO INR RAS were performed. The results are compared with the ones measured by the $^3$He proportional counter.

  7. Production of lithium positive ions from LiF thin films on the anode in PBFA II

    Energy Technology Data Exchange (ETDEWEB)

    Green, T.A.; Stinnett, R.W.; Gerber, R.A. [and others

    1995-09-01

    The production of positive lithium ions using a lithium-fluoride-coated stainless steel anode in the particle beam fusion accelerator PBFA II is considered from both the experimental and theoretical points of view. It is concluded that the mechanism of Li{sup +} ion production is electric field desorption from the tenth-micron-scale crystallites which compose the columnar growth of the LiF thin film. The required electric field is estimated to be of the order of 5 MV/cm. An essential feature of the mechanism is that the crystallites are rendered electronically conducting through electron-hole pair generation by MeV electron bombardment of the thin film during the operation of the diode. It is proposed that the ion emission mechanism is an electronic conductivity analogue to that discovered by Rollgen for lithium halide crystallites which were rendered ionically conducting by heating to several hundred degrees Celsius. Since an electric field desorption mechanism cannot operate if a surface flashover plasma has formed and reduced the anode electric field to low values, the possibility of flashover on the lithium fluoride coated anode of the PBFA II Li{sup +} ion source is studied theoretically. It is concluded with near certainty that flashover does not occur.

  8. Expression of LIF, VEGF,CD57 and CD68 after the transfer of rat embryos to mouse uteri

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The high failure rate of interspecific pregnancy is a major obstacle to the successful interspecific cloning of mammals. To investigate the reasons for the failure of interspecfic pregnancy between rats and mice, we transferred rat blastocysts into mouse uteri on the third day of pseudopregnancy (D3). Our previous study showed that intact rat embryos could still be observed in mouse uteri on D9. In the present study, we found that expression of CD57 and CD68 increased significantly at the maternal-fetal interface following the transfer of rat embryos. Similarly, Leukaemia inhibitory factor (LIF) expression increased, but vascular endothelial growth factor (VEGF) expession decreased. In a co-culture system, the percentage of rat ectoplacental cones (EPCs) with adhesion and outgrowth and outgrowth area on mouse uterine decidual cells were less than that of mouse EPCs. These results indicate that an increase in the immunological rejection response and a decrease in the invasiveness of rat embryos may be important reasons for the failure of interspecific pregnancy between rat and mouse.

  9. Manifestation of external field effect in time-resolved photo-dissociation dynamics of LiF

    Institute of Scientific and Technical Information of China (English)

    Meng Qing-Tian; A.J.C.Varandas

    2013-01-01

    The photo-dissociation dynamics of LiF is investigated with newly constructed accurate ab initio potential energy curves (PECs) using the time-dependent quantum wave packet method.The oscillations and decay of the wave packet on the adiabats as a function of time are given,which can be compared with the femtosecond transition-state (FTS) spectroscopy.The photo-absorption spectra and the kinetic-energy distribution of the dissociation fragments,which can exhibit the vibration-level structure and the dispersion of the wave packet,respectively,are also obtained.The investigation shows a blue shift of the band center for the photo-absorption spectrum and multiple peaks in the kinetic-energy spectrum with increasing laser intensity,which can be attributed to external field effects.By analyzing the oscillations of the wave packet evolving on the upper adiabat,an approximate inversion scheme is devised to roughly deduce its shape.

  10. Determination of DNA methylation by COBRA: a comparative study of CGE with LIF detection and conventional gel electrophoresis.

    Science.gov (United States)

    Goedecke, Simon; Schlosser, Sabrina; Mühlisch, Jörg; Hempel, Georg; Frühwald, Michael C; Wünsch, Bernhard

    2009-09-01

    DNA methylation as an epigenetic modification of the human genome is under emphatic investigation. Several studies have demonstrated a role of DNA methylation in oncogenesis. In conjunction with histone modifications, DNA methylation may cause the formation of heterochromatin and thus mediate the inactivation of gene transcription. It is important to develop methods that allow for an accurate quantification of the amount of DNA methylation in particular DNA regions, to gain information concerning the threshold of methylation levels necessary for gene inactivation. In this article, a CGE method with on-column LIF detection using SYBR Green is compared with a conventional slab-gel electrophoresis. We thus investigate the validity to analyze DNA methylation in the samples of a combined bisulfite restriction analysis. It is demonstrated that CGE is superior to gel electrophoresis in means of linearity, precision, accuracy, automatization (high throughput), and sample consumption. However, gel electrophoresis is easier to perform (simple devices, no PC usage), and the running costs are comparatively low. A further advantage of CGE is the sparse use of toxic compounds (MeOH and SYBR Green), whereas gel electrophoresis is performed in polyacrylamide gels with ethidium bromide staining.

  11. Predicted neutron yield and radioactivity for laser-induced (p,n) reactions in LiF

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D C; McNaney, J M

    2009-01-30

    Design calculations are presented for a pulsed neutron source comprising polychromatic protons accelerated from a metal foil by a short-pulse laser, and a LiF converter in which (p,n) reactions occur. Although the proton pulse is directional, neutrons are predicted to be emitted relatively isotropically. The neutron spectrum was predicted to be similar to the proton spectrum, but with more neutrons of low energy in the opposite direction to the incident protons. The angular dependence of spectrum and intensity was predicted. The (p,n) reactions generate unstable nuclei which decay predominantly by positron emission to the original {sup 7}Li and {sup 19}F isotopes. For the initial planned experiments using a converter 1mm thick, we predict that 0.1% of the protons will undergo a (p,n) reaction, producing 10{sup 9} neutrons. Ignoring the unreacted protons, neutrons, and prompt gamma emission as excited nuclear states decay, residual positron radioactivity (and production of pairs of 511 keV annihilation photons) is initially 4.2MBq decaying with a half-life of 17.22 s for 6 mins ({sup 19}Ne decays), then 135Bq decaying with a half-life of 53.22 days ({sup 7}Be decays).

  12. Simulations for a Staged Z-pinch and MagLIF at 26 MA, 130 ns, and 22 MJ

    Science.gov (United States)

    Rahman, Hafiz; Wessel, Frank; Ney, Paul; Narkis, Jeff; Valenzuela, Julio; Beg, Farhat; Presura, Radu

    2015-11-01

    Simulations for a Staged Z-pinch (SZP), using a 6-mm diameter, 100- μm thick Silver plasma shell, imploding onto a uniform (target) plasma fill of Deuterium, are compared to MagLIF, configured similarly, except with a 500 μm Beryllium solid liner. Both pinches are pre-magnetized with: Bz = 0, 3, 7, and 10 T and the driver parameters are: τ1 / 4 = 130 ns, Ipeak = 26 MA, Estored = 22 MJ; the simulation code is MACH2, a 2-1/2 D, radiation-MHD code. Solid-liner simulations reproduce well, experimental results. Plasma-liner simulations exhibit magnetosonic shocks in the liner and ordinary sonic shocks in the target, preheating the plasma. A conduction-channel, shock-front at the interface remains stable throughout compression, even as the liner's outer surface becomes RT unstable. At peak compression the target decelerates and interface instability appears, triggering ignition and a fusion yield of, Y > 200 MJ; that is, 10 × greater than Estored . The yield from the solid liner implosion is 4 orders-of-magnitude less, even though it is more stable than the SZP. Funded by the US Department of Energy, ARPA-E, Control Number 1184-1527.

  13. Estimating the atmospheric concentration of Criegee intermediates and their possible interference in a FAGE-LIF instrument

    Science.gov (United States)

    Novelli, Anna; Hens, Korbinian; Tatum Ernest, Cheryl; Martinez, Monica; Nölscher, Anke C.; Sinha, Vinayak; Paasonen, Pauli; Petäjä, Tuukka; Sipilä, Mikko; Elste, Thomas; Plass-Dülmer, Christian; Phillips, Gavin J.; Kubistin, Dagmar; Williams, Jonathan; Vereecken, Luc; Lelieveld, Jos; Harder, Hartwig

    2017-06-01

    We analysed the extensive dataset from the HUMPPA-COPEC 2010 and the HOPE 2012 field campaigns in the boreal forest and rural environments of Finland and Germany, respectively, and estimated the abundance of stabilised Criegee intermediates (SCIs) in the lower troposphere. Based on laboratory tests, we propose that the background OH signal observed in our IPI-LIF-FAGE instrument during the aforementioned campaigns is caused at least partially by SCIs. This hypothesis is based on observed correlations with temperature and with concentrations of unsaturated volatile organic compounds and ozone. Just like SCIs, the background OH concentration can be removed through the addition of sulfur dioxide. SCIs also add to the previously underestimated production rate of sulfuric acid. An average estimate of the SCI concentration of ˜ 5.0 × 104 molecules cm-3 (with an order of magnitude uncertainty) is calculated for the two environments. This implies a very low ambient concentration of SCIs, though, over the boreal forest, significant for the conversion of SO2 into H2SO4. The large uncertainties in these calculations, owing to the many unknowns in the chemistry of Criegee intermediates, emphasise the need to better understand these processes and their potential effect on the self-cleaning capacity of the atmosphere.

  14. Effects of transforming growth factor beta, tumor necrosis factor alpha, interferon gamma and LIF-HILDA on the proliferation of acute myeloid leukemia cells.

    Science.gov (United States)

    Kerangueven, F; Sempere, C; Tabilio, A; Mannoni, P

    1990-01-01

    A group of polypeptide factors that regulate cell growth and differentiation has been tested for their biological activities on the growth and differentiation of leukemic cells isolated from patients with Acute Myeloid Leukemias (AML). The effects of Transforming Growth Factor beta 1 (TGF beta), Tumor Necrosis Factor alpha (TNF alpha), Interferon gamma (IFN gamma) and LIF-HILDA were compared on leukemic cells cultured in vitro for seven days. Spontaneously growing leukemic cells were selected in order to study either inhibition or enhancement of proliferation induced by these factors. Only TGF beta 1 was found to induce a clear inhibition of leukemic proliferation in all cases tested. Recombinant TNF alpha and IFN gamma were found to induce either inhibition or enhancement of the proliferation on separate specimens. Under the conditions of culture, it was not possible to document any effect of LIF-HILDA. Cell differentiation and cell maturation were documented studying the modulation of cell surface antigens. TGF beta did not modify antigen expression on the cells surviving after 3 days in culture. Both TNF alpha and IFN gamma were found to enhance the expression of adhesion molecules and to a lesser extent, the expression of some lineage associated antigens. No effect of LIF-HILDA on antigen modulation was documented in the cases tested. These data confirm that TGF beta is by itself a potent inhibitor of the myeloid leukemia cells proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. In situ synchrotron X-ray powder diffraction for studying the role of induced structural defects on the thermoluminescence mechanism of nanocrystalline LiF.

    Science.gov (United States)

    El Ashmawy, Mostafa; Amer, Hany; Abdellatief, Mahmoud

    2016-03-01

    The correlation between the thermoluminescence (TL) response of nanocrystalline LiF and its microstructure was studied. To investigate the detailed TL mechanism, the glow curves of nanocrystalline LiF samples produced by high-energy ball-milling were analyzed. The microstructure of the prepared samples was analyzed by synchrotron X-ray powder diffraction (XRPD) at room temperature. Then, the microstructure of a representative pulverized sample was investigated in detail by performing in situ XRPD in both isothermal and non-isothermal modes. In the present study, the dislocations produced by ball-milling alter the microstructure of the lattice where the relative concentration of the vacancies, responsible for the TL response, changes with milling time. An enhancement in the TL response was recorded for nanocrystalline LiF at high-temperature traps (after dislocations recovery starts >425 K). It is also found that vacancies are playing a major role in the dislocations recovery mechanism. Moreover, the interactions among vacancies-dislocations and/or dislocations-dislocations weaken the TL response.

  16. Selenate enhances STAT3 transcriptional activity in endothelial cells: differential actions of selenate and selenite on LIF cytokine signaling and cell viability.

    Science.gov (United States)

    Alturkmani, Hani J; Zgheib, Carlos; Zouein, Fouad A; Alshaaer, Nour Eddin F; Kurdi, Mazen; Booz, George W

    2012-04-01

    Sodium selenate may have utility in treating Alzheimer's disease and diabetes; however, its impact on the associated proinflammatory cytokine signaling of endothelial cells has not been investigated. We report that treatment of human microvascular endothelial cells with sodium selenate at a pharmacological dose (100 μM) enhanced tyrosine phosphorylation of nuclear STAT3 on Y705 in response to IL-6-type cytokine, leukemia inhibitory factor (LIF), indicative of enhanced STAT3 activity. Accordingly, STAT3 nuclear binding to DNA was increased, as well as LIF-induced gene expression of chemokine (C-C motif) ligand 2 (CCL2). CCL2 plays a key role in inflammatory processes associated with neuronal degenerative and vascular diseases. The enhancing action of selenate on LIF-induced STAT3 Y705 phosphorylation was replicated by vanadate and a specific inhibitor of protein tyrosine phosphatase, non-receptor type 1 (PTP1B). Moreover, we observed that selenite, the cellular reduction bioproduct of selenate but not selenate itself, inhibited enzymatic activity of human recombinant PTP1B. Our findings support the conclusion that in human microvascular endothelial cells selenate has a vanadate-like effect in inhibiting PTP1B and enhancing proinflammatory STAT3 activation. These findings raise the possibility that beneficial actions of supranutritional levels of selenate for treating Alzheimer's and diabetes may be offset by a proinflammatory action on endothelial cells.

  17. First Results from Laser-Driven MagLIF Experiments on OMEGA: Time Evolution of Laser Gas Heating Using Soft X-Ray Diagnostics

    Science.gov (United States)

    Barnak, D. H.; Betti, R.; Chang, P.-Y.; Davies, J. R.

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising inertial confinement fusion scheme comprised of three stages: axial magnetization, laser heating of the deuterium -tritium gas fill, and compression of the gas by the liner. To study the physics of MagLIF, a scaled-down version has been designed and implemented on the OMEGA-60 laser. This talk will focus primarily on the heating process of a MagLIF target using a 351-nm laser. A neon-doped deuterium gas capsule was heated using a 2.5-ns square pulse delivering 200 J of laser energy. Spectral analysis of the x-ray emission from the side and the laser entrance hole of the capsule is used to infer the time evolution of the gas temperature. The x-ray spectra for a grid of possible gas temperatures and densities are simulated using Spect3D atomic modeling software. The simulation results are then used to deconvolve the raw signals and obtain density and temperature estimations. A gas temperature lower bound of 100 eV at 1.3 ns after the start of the laser pulse can be inferred from these estimations. The estimations are then compared to 2-D hydrocode modeling. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and by DE-FG02-04ER54786 and DE-FC02-04ER54789 (Fusion Science Center).

  18. Development of antireflection coatings with a sup 6 LiF/ sup 6 sup 2 Ni multilayer converter for ultracold neutron detectors

    CERN Document Server

    Maier-Komor, P; Bergmaier, A; Dollinger, G; Paul, S; Schott, W

    2002-01-01

    High efficiency detectors for ultracold neutrons (UCN) are needed at the new high flux neutron source, Forschungsreaktor Muenchen II. In the development described, silicon PIN diodes were chosen to detect the alpha-particles or the tritons created in the reaction sup 6 Li(n,alpha)t. The high reflectance of UCN on sup 6 Li with its positive optical potential must be compensated by a material with negative optical potential. The isotope sup 6 sup 2 Ni was chosen for this. To avoid problems due to chemical reactions of Li with humidity, the compound sup 6 LiF was chosen. One hundred and fifty double layers of sup 6 LiF/ sup 6 sup 2 Ni had to be deposited by physical vapor deposition on silicon PIN diodes which had already been coated with 88 nm approx 77 mu g/cm sup 2 of sup 5 sup 8 Ni for reflection of the UCN. The theoretical optimal thickness of the sup 6 sup 2 Ni layers is 3 nm, and that of sup 6 LiF is 6 nm. Since expensive isotopes were involved, a small source-to-substrate distance had to be used, but wit...

  19. Effect of fluctuations on time-averaged multi-line NO-LIF thermometry measurements of the gas-phase temperature

    Science.gov (United States)

    Feroughi, Omid M.; Kronemayer, Helmut; Dreier, Thomas; Schulz, Christof

    2015-09-01

    Multi-line NO laser-induced fluorescence (LIF) thermometry enables accurate gas-phase temperature imaging in combustion systems through least-squares fitting of excitation spectra. The required excitation wavelength scan takes several minutes which systematic biases the results in case of temperature fluctuations. In this work, the effect of various types (linear, Gaussian and bimodal) and amplitudes of temperature fluctuations is quantified based on simulated NO-LIF excitation spectra. Temperature fluctuations of less than ±5 % result in a negligible error of less than ±1 % in temperature for all cases. Bimodal temperature distributions have the largest effect on the determined temperature. Symmetric temperature fluctuations around 900 K have a negligible effect. At lower mean temperatures, fluctuations cause a positive bias leading to over-predicted mean temperatures, while at higher temperatures the bias is negative. The results of the theoretical analysis were applied as a guide for interpreting experimental multi-line NO-LIF temperature measurements in a mildly turbulent pilot-plant scale flame reactor dedicated for nanoparticle synthesis.

  20. Irradiation Creep in Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

  1. First Results from Laser-Driven MagLIF Experiments on OMEGA: Backscatter and Transmission Measurements of Laser Preheating

    Science.gov (United States)

    Davies, J. R.; Barnak, D. H.; Betti, R.; Chang, P.-Y.

    2015-11-01

    A laser-driven version of MagLIF (magnetized liner inertial fusion) is being developed on the OMEGA laser. In the first experiment, laser preheating with a single OMEGA beam was studied. Laser energies of 60 to 200 J in 2.5-ns-long pulses were used, with a distributed phase plate giving a Gaussian intensity profile with a 96 μm full width at half maximum. We report on backscatter measurements from gas-filled cylinders and both backscatter and transmission measurements from the 1.84- μm-thick polyimide foils used for the laser entrance windows. Backscatter spectra and energies from both cylinders and foils alone were very similar. Approximately 0.5% of the total incident laser energy was backscattered. Backscattering lasted for little more than 0.5 ns. The fraction of laser energy transmitted through foils within the original beam path increased from 50% to 64% as the laser energy was increased from 60 to 200 J. Up to 10% of the laser energy was sidescattered as the foil started to transmit. Sidescattering of transmitted light lasted ~0.5 ns. The sidescattering might be avoided by using a short prepulse at least 0.5 ns prior to the main pulse. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and by DE-FG02-04ER54786 and DE-FC02-04ER54789 (Fusion Science Center).

  2. Soft x-ray source for nanostructure imaging using femtosecond-laser-irradiated clusters

    Science.gov (United States)

    Fukuda, Y.; Faenov, A. Ya.; Pikuz, T.; Kando, M.; Kotaki, H.; Daito, I.; Ma, J.; Chen, L. M.; Homma, T.; Kawase, K.; Kameshima, T.; Kawachi, T.; Daido, H.; Kimura, T.; Tajima, T.; Kato, Y.; Bulanov, S. V.

    2008-03-01

    The intense soft x-ray light source using the supersonic expansion of the mixed gas of He and CO2, when irradiated by a femtosecond Ti:sapphire laser pulse, is observed to enhance the radiation of soft x-rays from the CO2 clusters. Using this soft x-ray emissions, nanostructure images of 100-nm-thick Mo foils in a wide field of view (mm2 scale) with high spatial resolution (800nm ) are obtained with high dynamic range LiF crystal detectors. The local inhomogeneities of soft x-ray absorption by the nanometer-thick foils is measured with an accuracy of less than ±3%.

  3. AGC-2 Irradiation Report

    Energy Technology Data Exchange (ETDEWEB)

    Rohrbaugh, David Thomas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Windes, William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Swank, W. David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-06-01

    The Next Generation Nuclear Plant (NGNP) will be a helium-cooled, very high temperature reactor (VHTR) with a large graphite core. In past applications, graphite has been used effectively as a structural and moderator material in both research and commercial high temperature gas cooled reactor (HTGR) designs.[ , ] Nuclear graphite H 451, used previously in the United States for nuclear reactor graphite components, is no longer available. New nuclear graphites have been developed and are considered suitable candidates for the new NGNP reactor design. To support the design and licensing of NGNP core components within a commercial reactor, a complete properties database must be developed for these current grades of graphite. Quantitative data on in service material performance are required for the physical, mechanical, and thermal properties of each graphite grade with a specific emphasis on data related to the life limiting effects of irradiation creep on key physical properties of the NGNP candidate graphites. Based on experience with previous graphite core components, the phenomenon of irradiation induced creep within the graphite has been shown to be critical to the total useful lifetime of graphite components. Irradiation induced creep occurs under the simultaneous application of high temperatures, neutron irradiation, and applied stresses within the graphite components. Significant internal stresses within the graphite components can result from a second phenomenon—irradiation induced dimensional change. In this case, the graphite physically changes i.e., first shrinking and then expanding with increasing neutron dose. This disparity in material volume change can induce significant internal stresses within graphite components. Irradiation induced creep relaxes these large internal stresses, thus reducing the risk of crack formation and component failure. Obviously, higher irradiation creep levels tend to relieve more internal stress, thus allowing the

  4. Irradiation Defects in Silicon Crystal

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The application of irradiation in silicon crystal is introduced.The defects caused by irradiation are reviewed and some major ways of studying defects in irradiated silicon are summarized.Furthermore the problems in the investigation of irradiated silicon are discussed as well as its properties.

  5. Food irradiation; Napromieniowanie zywnosci

    Energy Technology Data Exchange (ETDEWEB)

    Migdal, W. [Instytut Chemii i Techniki Jadrowej, Doswiadczalna Stacja Radiacyjnego Utrwalania Plodow Rolnych, Warsaw (Poland)

    1995-12-31

    A worldwide standard on food irradiation was adopted in 1983 by codex Alimentarius Commission of the Joint Food Standard Programme of the Food and Agriculture Organization (FAO) of the United Nations and The World Health Organization (WHO). As a result, 41 countries have approved the use of irradiation for treating one or more food items and the number is increasing. Generally, irradiation is used to: food loses, food spoilage, disinfestation, safety and hygiene. The number of countries which use irradiation for processing food for commercial purposes has been increasing steadily from 19 in 1987 to 33 today. In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in Inst. of Nuclear Chemistry and Technology. The plant is equipped with a small research accelerator Pilot (19 MeV, 1 kW) and industrial unit Electronika (10 MeV, 10 kW). On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permissions for irradiation for; spices, garlic, onions, mushrooms, potatoes, dry mushrooms and vegetables. (author) 14 refs, 3 tabs

  6. Total lymphoid irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1983-05-01

    Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen.

  7. Irradiation and food processing.

    Science.gov (United States)

    Sigurbjörnsson, B; Loaharanu, P

    1989-01-01

    After more than four decades of research and development, food irradiation has been demonstrated to be safe, effective and versatile as a process of food preservation, decontamination or disinfection. Its various applications cover: inhibition of sprouting of root crops; insect disinfestation of stored products, fresh and dried food; shelf-life extension of fresh fruits, vegetables, meat and fish; destruction of parasites and pathogenic micro-organisms in food of animal origin; decontamination of spices and food ingredients, etc. Such applications provide consumers with the increase in variety, volume and value of food. Although regulations on food irradiation in different countries are largely unharmonized, national authorities have shown increasing recognition and acceptance of this technology based on the Codex Standard for Irradiated Foods and its associated Code of Practice. Harmonization of national legislations represents an important prerequisite to international trade in irradiated food. Consumers at large are still not aware of the safety and benefits that food irradiation has to offer. Thus, national and international organizations, food industry, trade associations and consumer unions have important roles to play in introducing this technology based on its scientific values. Public acceptance of food irradiation may be slow at the beginning, but should increase at a faster rate in the foreseeable future when consumers are well informed of the safety and benefits of this technology in comparison with existing ones. Commercial applications of food irradiation has already started in 18 countries at present. The volume of food or ingredients treated on a commercial scale varies from country to country ranging from several tons of spices to hundreds of thousands of tons of grains per annum. With the increasing interest of national authorities and the food industry in applying the process, it is anticipated that some 25 countries will use some 55 commercial

  8. THE EFFECT OF RECOMBINANT HUMAN LEUKEMIA INHIBITORY FACTOR (rhLIF ON IN VITRO DEVELOPMENT OF MOUSE 2-CELL EMBRYOS AND THEIR ISOLATED BLASTOMERES

    Directory of Open Access Journals (Sweden)

    MOHAMMAD AKBARI

    2004-09-01

    Full Text Available In this study effect of recombinant human leukemia inhibitory factor on invitro development of 2 cells embryos and isolated blastomeres derived from mouse 2 cell embryos were investigated. Female ICR mice that were between 8 to 10 weeks old received intraperitoneal injection of 7.5 IU of PMSG for super ovulation followed by intraperitoneal administration of 7.5 IU of HCG 48 hours later. The mice were then mated to mature ICR male mice and were checked for vaginal plugs after 13-14 hours. Mice were killed 46-48 hours after HCG injection by cervical dislocation, their oviducts were removed and flushing 2 cell embryos were collected. The zona pellucida of 2 cell embryos were removed by Acid Tyrod solution and blastomeres separated with oocyte preparation pipette and then all embryos and blastomeres were cultured in Potassium Simplex Optimized Medium (KSOM +Aminoacid (AA different amounts of rhLIF (500IU/ml, 1000IU/ml and 1500IU/ml. Some embryos and individual blastomere also were cultured without rhLIF as control group. All samples were cultured in an incubator at 370C with 0.05 CO2 for 120 hours. The rate of embryo and individual blastomeres which reached to 2 cell, 4 cell, 8 cell and 9-16 cell were the same in all groups. However in further developmental stages, morula and blastocyst between experimental and control groups were significantly different. Therefore it may be concluded that: cultivation of isolated blastomers up to the blastocyst stage with rhLIF has stimulatory effect on the preimplantation stage (morula and blastocyst but it has no stimulatory and inhibitory effects when was added to culture media at the early cleavage stage.

  9. Hypothyroidism advances mammary involution in lactating rats through inhibition of PRL signaling and induction of LIF/STAT3 mRNAs.

    Science.gov (United States)

    Campo Verde Arboccó, Fiorella; Sasso, Corina V; Actis, Esteban A; Carón, Rubén W; Hapon, María Belén; Jahn, Graciela A

    2016-01-01

    Thyroid diseases have deleterious effects on lactation, litter growth and survival, and hinder the suckling-induced hormone release, leading in the case of hyperthyroidism, to premature mammary involution. To determine the effects of hypothyroidism (HypoT) on late lactation, we analyzed the effect of chronic 6-propyl-2-thiouracil (PTU)-induced HypoT on mammary histology and the expression of members of the JAK/STAT/SOCS signaling pathway, milk proteins, prolactin (PRLR), estrogen (ER), progesterone (PR) and thyroid hormone (TR) receptors, markers of involution (such as stat3, lif, bcl2, BAX and PARP) on lactation (L) day 21. HypoT mothers showed increased histological markers of involution compared with control rats, such as adipose/epithelial ratio, inactive alveoli, picnotic nuclei and numerous detached apoptotic cells within the alveolar lumina. We also found decreased PRLR, β-casein and α-lactoalbumin mRNAs, but increased SOCS1, SOCS3, STAT3 and LIF mRNAs, suggesting a decrease in PRL signaling and induction of involution markers. Furthermore, Caspase-3 and 8 and PARP labeled cells and the expression of structural proteins such as β-Actin, α-Tubulin and Lamin B were increased, indicating the activation of apoptotic pathways and tissue remodelation. HypoT also increased PRA (mRNA and protein) and erβ and decreased erα mRNAs, and increased strongly TRα1, TRβ1, PRA and ERα protein levels. These results show that lactating HypoT rats have premature mammary involution, most probably induced by the inhibition of prolactin signaling along with the activation of the LIF-STAT3 pathway.

  10. First-principles study of the threshold effect in the electronic stopping power of LiF and SiO2 for low-velocity protons and helium ions

    Science.gov (United States)

    Mao, Fei; Zhang, Chao; Dai, Jinxia; Zhang, Feng-Shou

    2014-02-01

    Nonadiabatic dynamics simulations are performed to investigate the electronic stopping power of LiF and SiO2-cristobalite-high crystalline thin films when protons and helium ions are hyperchanneling in the axis. In this theoretical framework, ab initio time-dependent density-functional theory calculations for electrons are combined with molecular dynamics simulations for ions in real time and real space. The energy transfer process between the ions and the electronic subsystem of LiF and SiO2 nanostructures is studied. The velocity-proportional stopping power of LiF and SiO2 for protons and helium ions is predicted in the low-energy range. The measured velocity thresholds of protons in LiF and SiO2, and helium ions in LiF are reproduced. The convergence of the threshold effect with respect to the separation of grid points is confirmed. The underlying physics of the threshold effect is clarified by analyzing the conduction band electron distribution. In addition, the electron transfer processes between the projectile ions and solid atoms in hyperchanneling condition are studied, and its effects on the energy loss is investigated.

  11. Scattering of H(D) from LiF(1 0 0) under fast grazing incidence conditions: To what extent is classical dynamics a useful tool?

    Energy Technology Data Exchange (ETDEWEB)

    Muzas, A.S. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Martín, F. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-nanociencia), Cantoblanco, 28049 Madrid (Spain); Díaz, C., E-mail: cristina.diaz@uam.es [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-07-01

    Diffraction experiments of atoms and molecules under fast grazing incidence conditions have opened a new field in surface science. This experimental effort calls for complementary theoretical studies, which would allow a detailed analysis of experimental data. Here, we have analyzed the ability of classical dynamics simulations to reproduce experimental results. To perform this study, a DFT (density functional theory) based potential energy surface, describing the interaction between a H atom and a LiF(1 0 0) surface, has been computed. Diffraction probabilities have been simulated by means of a classical binning method. Our results have been found to be in qualitative good agreement with recent experimental measurements.

  12. Electronic processes near kinematic threshold for grazing scattering of fast hydrogen atoms from a LiF(0 0 1) surface

    CERN Document Server

    Lederer, S; Winter, H; Aumayr, F; Winter, H P; Staemmler, V

    2003-01-01

    In coincident studies on projectile energy loss and number distributions of emitted electrons for scattering of hydrogen atoms from an atomically clean and flat LiF(0 0 1) surface we derive probabilities for emission of electrons and production of surface excitons near their respective kinematic thresholds. We analyze our data in terms of electron transfer in binary atomic collisions with one collision partner being embedded at the anion site of an ionic crystal and derive information on the energy defects in these collisions.

  13. Monte Carlo studies on water and LiF cavity properties for dose-reporting quantities when using x-ray and brachytherapy sources

    Science.gov (United States)

    Soares Lopes Branco, Isabela; Guimarães Antunes, Paula Cristina; Paiva Fonseca, Gabriel; Yoriyaz, Hélio

    2016-12-01

    Model-based dose calculation algorithms (MBDCAs) are the current tools to estimate dose in brachytherapy, which takes into account heterogeneous medium, therefore, departing from water-based formalism (TG-43). One aspect associated to MBCDA is the choice of dose specification medium since it offers two possibilities to report dose: (a) dose to medium in medium, D m,m; and (b) dose to water in medium, D w,m. The discussion about the preferable quantity to be reported is underway. The dose conversion factors, DCF, between dose to water in medium, D w,m, and dose to medium in medium, D m,m, is based on cavity theory and can be obtained using different approaches. When experimental dose verification is desired using, for example, thermoluminescent LiF dosimeters, as in in vivo dose measurements, a third quantity is obtained, which is the dose to LiF in medium, D LiF,m. In this case, DCF to convert from D LiF,m to D w,m or D m,m is necessary. The objective of this study is to estimate DCFs using different approaches, present in the literature, quantifying the differences between them. Also, dose in water and LiF cavities in different tissue media and respective conversion factors to be able to convert LiF-based dose measured values into dose in water or tissue were obtained. Simple cylindrical phantoms composed by different tissue equivalent materials (bone, lung, water and adipose) are modelled. The phantoms contain a radiation source and a cavity with 0.002 69 cm3 in size, which is a typical volume of a disc type LiF dosimeter. Three x-rays qualities with average energies ranging from 47 to 250 keV, and three brachytherapy sources, 60Co, 192Ir and 137Cs, are considered. Different cavity theory approaches for DCF calculations and different cavity/medium combinations have been considered in this study. DCF values for water/bone and LiF/bone cases have strong dependence with energy increasing as the photon energy increases. DCF values also increase with energy for

  14. Interaction potentials for multi-electron atoms in front of a LiF (0 0 1) surface from rainbow scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gravielle, M.S. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, C1428EGA Buenos Aires (Argentina); Miraglia, J.E., E-mail: miraglia@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Casilla de correo 67, sucursal 28, C1428EGA Buenos Aires (Argentina); Schüller, A.; Winter, H. [Institut für Physik, Humboldt Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin-Adlershof (Germany)

    2013-12-15

    Pairwise interaction potentials for multi-electron atoms moving in front of a LiF (0 0 1) surface are investigated theoretically and experimentally. From angular distributions of fast He, N, S, Cl and Kr atoms grazingly scattered under axial surface channeling conditions, rainbow angles are experimentally determined for a wide range of energies for the motion normal to the surface plane. These angles are used as a benchmark to probe the pairwise potential model. In the simulations the scattering process is described by means of the surface eikonal approximation, while the atom–surface interaction is derived by adding binary interatomic potentials that include the proper asymptotic limit.

  15. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    OpenAIRE

    Mosset, J. -B.; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2015-01-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC^4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC^4 filter has been emulated digitally. The dete...

  16. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    Science.gov (United States)

    Mosset, J.-B.; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2016-07-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC4 filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach.

  17. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    CERN Document Server

    Mosset, J -B; Greuter, U; Hildebrandt, M; Schlumpf, N

    2015-01-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC^4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC^4 filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach.

  18. A new LIF instrument for aircraft related and ground related masurements of OH and HO{sub 2} radicals in the troposphere; Ein neues LIF-Instrument fuer flugzeug- und bodengebundene Messungen von OH- und HO{sub 2}-Radikalen in der Troposphaere

    Energy Technology Data Exchange (ETDEWEB)

    Broch, Sebastian

    2011-07-01

    The author of the contribution under consideration describes the development and characterization of an instrument for the measurement of OH and HO{sub 2} radicals by means of laser-induced fluorescence (LIF). This instrument can be used from the lower troposphere to the lower stratosphere both on the ground and in aircraft applications. After describing the basics of the OH radical chemistry and the measurement principle of laser-induced fluorescence, a new instrument is presented. The LIF measuring cells needs long inlet pipes which lead to a modification of the verification of OH radicals. The effect of these modifications as well as the height dependence of the detection sensitivity for the OH radicals is examined. A model for the theoretical description of the altitude dependence of the detection sensitivity is described. The modification of the measuring cell influences the ozone-water interference in the LIF measurement system. Therefore, the author develops a model to describe the interference in the new system and evaluate this model by measurements. The applicability of this new instrument for ground and flight applications is analyzed in the range from 0 to 18 kilometers regarding sensitivity, detection limit and interference.

  19. The Birmingham Irradiation Facility

    Science.gov (United States)

    Dervan, P.; French, R.; Hodgson, P.; Marin-Reyes, H.; Wilson, J.

    2013-12-01

    At the end of 2012 the proton irradiation facility at the CERN PS [1] will shut down for two years. With this in mind, we have been developing a new ATLAS scanning facility at the University of Birmingham Medical Physics cyclotron. With proton beams of energy approximately 30 MeV, fluences corresponding to those of the upgraded Large Hadron Collider (HL-LHC) can be reached conveniently. The facility can be used to irradiate silicon sensors, optical components and mechanical structures (e.g. carbon fibre sandwiches) for the LHC upgrade programme. Irradiations of silicon sensors can be carried out in a temperature controlled cold box that can be scanned through the beam. The facility is described in detail along with the first tests carried out with mini (1×1 cm2) silicon sensors.

  20. The Birmingham Irradiation Facility

    CERN Document Server

    Dervan, P; Hodgson, P; Marin-Reyes, H; Wilson, J

    2013-01-01

    At the end of 2012 the proton irradiation facility at the CERN PS [1] will shut down for two years. With this in mind, we have been developing a new ATLAS scanning facility at the University of Birmingham Medical Physics cyclotron. With proton beams of energy approximately 30 MeV, fluences corresponding to those of the upgraded Large Hadron Collider (HL-LHC) can be reached conveniently. The facility can be used to irradiate silicon sensors, optical components and mechanical structures (e.g. carbon fibre sandwiches) for the LHC upgrade programme. Irradiations of silicon sensors can be carried out in a temperature controlled cold box that can be scanned through the beam. The facility is described in detail along with the first tests carried out with mini (1 x 1 cm^2 ) silicon sensors.

  1. Irradiation of food

    Energy Technology Data Exchange (ETDEWEB)

    MacGregor, J.; Stanbrook, I.; Shersby, M.

    1989-07-12

    The House of Commons was asked to support the Government's intention to allow the use of the irradiation of foodstuffs under conditions that will fully safeguard the interests of the consumer. The Government, it was stated, regards this process as a useful additional way to ensure food safety. The effect of the radiation in killing bacteria will enhance safety standards in poultry meat, in some shell-fish and in herbs and spices. The problem of informing the public when the food has been irradiated, especially as there is no test to detect the irradiation, was raised. The subject was debated for an hour and a half and is reported verbatim. The main point raised was over whether the method gave safer food as not all bacteria were killed in the process. The motion was carried. (U.K.).

  2. Fabrication and characterization of new LiF: Eu{sup 3+} sintered phosphors exposed to beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Garcia H, A.R.; Cruz V, C. [Depto. de Investigacion en Polimeros y Materiales de la Universidad de Sonora, A.P. 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R.; Barboza F, M. [Universidad de Sonora, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Kitis, G. [Nuclear Physics Laboratory, Aristotle University of Thessaloniki, 54124 (Greece); Castano, V.M. [IFUNAM, A.P. 1-1010, 76000 Queretaro (Mexico)

    2006-07-01

    Pellet-shaped LiF:Eu{sup 3+} phosphors were synthesized by sintering. To improve their thermoluminescence characteristics, different growth conditions were used. Thermal annealing at 750 C during 5 h under air atmosphere provided the samples with highest sensitivity. Characteristic glow curves exhibit an absolute maximum centered at 203 C, and another less intense peak between 250 and 300 C. The first peak has a position very suitable for dosimetry applications. Beta irradiated samples displayed a thermoluminescence response that increases as the radiation dose increased in the 0.16 - 42.0 Gy range. A fast fading of less than 20 % occurs in the first 10 s after irradiation, followed by a remarkable stability at room temperature. Computerized glow curve deconvolution of experimental data obtained applying the McKeever method to resolve the individual peaks revealed that the glow curves fits to nine individual peaks. Activation energies were computed by using the initial rise method. (Author)

  3. LIF和IGF-1对牛胚胎干细胞分离的影响%Influences of LIF and IGF-1 on the isolation of bovine ES cells

    Institute of Scientific and Technical Information of China (English)

    杨奇; 窦忠英

    2002-01-01

    比较了添加LIF,IGF-1和LIF+IGF对牛胚胎干细胞(ES)分离的影响.结果表明:①添加\\{10 ng/mL\\} LIF能提高胚胎贴壁率,促进内细胞团(ICM)和ES细胞的增殖并抑制其分化;②添加10 ng/mL IGF-1既能提高胚胎贴壁率,又能使ICM明显增殖的时间和传代后集落出现的时间提前;③添加10 ng/mL LIF+\\{10 ng/mL\\} IGF-1,可以同时发挥两种生长因子的作用效果,更有利于牛胚胎干细胞的分离.

  4. Measurement of a wide-range of X-ray doses using specialty doped silica fibres

    Science.gov (United States)

    Abdul Sani, S. F.; Hammond, R.; Jafari, S. M.; Wahab, Norfadira; Amouzad Mahdiraji, G.; Siti Shafiqah, A. S.; Abdul Rashid, H. A.; Maah, M. J.; Aldousari, H.; Alkhorayef, M.; Alzimami, M.; Bradley, D. A.

    2017-08-01

    Using six types of tailor-made doped optical fibres, we carry out thermoluminescent (TL) studies of X-rays, investigating the TL yield for doses from 20 mGy through to 50 Gy. Dosimetric parameters were investigated for nominal 8 wt% Ge doped fibres that in two cases were co-doped, using B in one case and Br in the other. A comparative measurement of surface analysis has also been made for non-annealed and annealed capillary fibres, use being made of X-ray Photoelectron Spectroscopy (XPS) analysis. Comparison was made with the conventional TL phosphor LiF in the form of the proprietary product TLD-100, including dose response and glow curves investigated for X-rays generated at 60 kVp over a dose range from 2 cGy to 50 Gy. The energy response of the fibres was also performed for X-rays generated at peak accelerating potentials of 80 kVp, 140 kVp, 250 kVp and 6 MV photons for an absorbed dose of 2 Gy. Present results show the samples to be suitable for use as TL dosimeters, with good linearity of response and a simple glow curve (simple trap) distribution. It has been established that the TL performance of an irradiated fibre is not only influenced by radiation parameters such as energy, dose-rate and total dose but also the type of fibre.

  5. Direct Measurements of the Spatial and Velocity Dependence of the Ion Density Fluctuation Spectrum of a Laboratory Plasma with Two Independent LIF Schemes

    Science.gov (United States)

    Mattingly, Sean; Berumen, Jorge; Chu, Feng; Hood, Ryan; Skiff, Fred

    2014-10-01

    By using two independently tunable lasers, each with its own collection optics and Ar II LIF transition scheme, we are able to investigate plasma ion density fluctuations as a function of not only spatial scales but also as a function of ion velocities as sampled on different points of a single Doppler-broadened spectral emission line. We do this by measuring the two point correlation C (x , v ,x' ,v' , τ) = t . With the current system, the two carriages determine x and x', while the velocities selected by each laser determine v and v'. Using the two lasers to make two point correlations in phase space demonstrates effects that are not fully understood. In this experiment, we explore the striking difference in correlations when, in the past, the particle orbits overlap in space versus when they do not overlap. This is performed on a small cylindrical laboratory plasma with n ~109 cm-3 , Te ~ 5 eV, Ti ~ 0 . 06 , and a 1 kG axial magnetic field. LIF is performed on ions at two locations aligned with the magnetic field line with a viewing volume comparable to the size of the Larmor radius. Results and interpretations from these experiments are presented and discussed. DOE Grant DE-FG02-99ER54543.

  6. Regulation of mouse embryonic stem cell self-renewal by a Yes-YAP-TEAD2 signaling pathway downstream of LIF.

    Science.gov (United States)

    Tamm, Christoffer; Böwer, Nathalie; Annerén, Cecilia

    2011-04-01

    The cytoplasmic tyrosine kinase Yes has previously been shown to have an important role in maintaining mouse and human embryonic stem (ES) self-renewal through an unknown pathway downstream of leukemia inhibitory factor (LIF) and one or more factors in serum. Here, we show that TEAD2 and its transcriptional co-activator, the Yes-associated protein YAP, co-operate in a signaling pathway downstream of Yes. We show that YAP, TEAD2 and Yes are highly expressed in self-renewing ES cells, are activated by LIF and serum, and are downregulated when cells are induced to differentiate. We also demonstrate that kinase-active Yes binds and phosphorylates YAP, and activates YAP-TEAD2-dependent transcription. We found that TEAD2 associates directly with the Oct-3/4 promoter. Moreover, activation of the Yes pathway induced activity of the Oct-3/4 and Nanog promoters, whereas suppression of this pathway inhibited promoter activity. Nanog, in turn, suppressed TEAD2-dependent promoter activity, whereas siRNA-mediated knockdown of Nanog induced it, suggesting a negative regulatory feedback loop. Episomal supertransfection of cells with inhibitory TEAD2-EnR induced endodermal differentiation, which suggests that this pathway is necessary for ES cell maintenance.

  7. An ultracold neutron (UCN) detector with Ti/ sup 6 LiF multi-layer converter and sup 5 sup 8 Ni reflector

    CERN Document Server

    Maier-Komor, P; Bergmaier, A; Dollinger, G; Paul, S; Petzoldt, G; Schott, W

    2002-01-01

    High efficient detectors for ultracold neutrons (UCN) must be developed for the new high flux neutron source Forschungsreaktor Muenchen II (FRM II). On silicon PIN diodes 76 mu g/cm sup 2 sup 5 sup 8 Ni was deposited as a UCN reflector. On this 100 double layers of sup n sup a sup t Ti (4.7 mu g/cm sup 2) and sup 6 LiF (1.8 mu g/cm sup 2) were deposited to function as a UCN converter. On top of this, 33 double layers of sup n sup a sup t Ti (3.4 mu g/cm sup 2) and sup 6 LiF (0.92 mu g/cm sup 2) were condensed in addition to provide sensitivity to very low-energy UCN. Finally, 6.0 mu g/cm sup 2 sup n sup a sup t V was deposited to protect the multi-layers. Vanadium has nearly zero optical potential for UCN and thus should not hinder their transmission. Since no expensive isotopes were involved, a source to substrate distance of 24 cm could be chosen, leading to excellent uniformity. The setup designed for deposition under ultrahigh vacuum conditions and the evaporation procedures are described.

  8. Quantitative impurity analysis of monoclonal antibody size heterogeneity by CE-LIF: example of development and validation through a quality-by-design framework.

    Science.gov (United States)

    Michels, David A; Parker, Monica; Salas-Solano, Oscar

    2012-03-01

    This paper describes the framework of quality by design applied to the development, optimization and validation of a sensitive capillary electrophoresis-sodium dodecyl sulfate (CE-SDS) assay for monitoring impurities that potentially impact drug efficacy or patient safety produced in the manufacture of therapeutic MAb products. Drug substance or drug product samples are derivatized with fluorogenic 3-(2-furoyl)quinoline-2-carboxaldehyde and nucleophilic cyanide before separation by CE-SDS coupled to LIF detection. Three design-of-experiments enabled critical labeling parameters to meet method requirements for detecting minor impurities while building precision and robustness into the assay during development. The screening design predicted optimal conditions to control labeling artifacts while two full factorial designs demonstrated method robustness through control of temperature and cyanide parameters within the normal operating range. Subsequent validation according to the guidelines of the International Committee of Harmonization showed the CE-SDS/LIF assay was specific, accurate, and precise (RSD ≤ 0.8%) for relative peak distribution and linear (R > 0.997) between the range of 0.5-1.5 mg/mL with LOD and LOQ of 10 ng/mL and 35 ng/mL, respectively. Validation confirmed the system suitability criteria used as a level of control to ensure reliable method performance.

  9. Microchip CE-LIF method for the hydrolysis of L-glutamine by using L-asparaginase enzyme reactor based on gold nanoparticle.

    Science.gov (United States)

    Qiao, Juan; Qi, Li; Yan, Huijuan; Li, Yaping; Mu, Xiaoyu

    2013-02-01

    L-Asparaginase (L-Asnase) can suppress the growth of malignant cells by rapid depletion of two essential amino acids, L-glutamine (L-Gln) and L-asparagine (L-Asn). To study the cytotoxic effect and the secondary complications of L-Asnase in the treatment of acute lymphoblastic leukemia, the development of a novel enzyme reactor of L-Asnase for the hydrolysis of L-Gln, employing the enzyme-gold nanoparticle conjugates in capillary, was reported in this work. First, a microchip CE (MCE)-LIF was established for the separation of L-amino acids (L-Gln and L-glutamic acid) and studying the hydrolysis of L-Gln by using L-Asnase enzyme reactor. Then, using L-Gln as target analyte, the enzyme kinetics of L-Asnase in free solution, enzyme-gold nanoparticle conjugates (E-GNP), and the enzyme-gold nanoparticle conjugates immobilized in capillary (E-GNP-C) were investigated in detail with the proposed MCE-LIF method. Moreover, for optimizing the enzymatic reaction efficiency, three important parameters, including the length of capillary, the enzyme concentration reacted with gold nanoparticle and the amount of L-Asnase immobilized on the gold nanoparticle, have been studied. Owing to the high specific activity, the E-GNP-C enzyme reactor exhibited the best performance for the hydrolysis of L-Gln.

  10. Solar Irradiance Variability

    CERN Document Server

    Solanki, Sami K

    2012-01-01

    The Sun has long been considered a constant star, to the extent that its total irradiance was termed the solar constant. It required radiometers in space to detect the small variations in solar irradiance on timescales of the solar rotation and the solar cycle. A part of the difficulty is that there are no other constant natural daytime sources to which the Sun's brightness can be compared. The discovery of solar irradiance variability rekindled a long-running discussion on how strongly the Sun affects our climate. A non-negligible influence is suggested by correlation studies between solar variability and climate indicators. The mechanism for solar irradiance variations that fits the observations best is that magnetic features at the solar surface, i.e. sunspots, faculae and the magnetic network, are responsible for almost all variations (although on short timescales convection and p-mode oscillations also contribute). In spite of significant progress important questions are still open. Thus there is a debat...

  11. NSUF Irradiated Materials Library

    Energy Technology Data Exchange (ETDEWEB)

    Cole, James Irvin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

  12. Cellular Response to Irradiation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; YAN Shi-Wei

    2011-01-01

    To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions.It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

  13. Wholesomeness of irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Raica, Nicholas; McDowell, Marion E.; Darby, William J.

    1963-01-15

    The wholesomeness of irradiated foods was evaluated in mice, rats, dogs, and monkeys over a 2-year period, or 4 generations. Data are presented on the effects of a diet containing radiation-processed foods on growth, reproduction, hematology, histopathology, carcinogenicity, and life span. (86 references) (C.H.)

  14. Post irradiation test report of irradiated DUPIC simulated fuel

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Myung Seung; Jung, I. H.; Moon, J. S. and others

    2001-12-01

    The post-irradiation examination of irradiated DUPIC (Direct Use of Spent PWR Fuel in CANDU Reactors) simulated fuel in HANARO was performed at IMEF (Irradiated Material Examination Facility) in KAERI during 6 months from October 1999 to March 2000. The objectives of this post-irradiation test are i) the integrity of the capsule to be used for DUPIC fuel, ii) ensuring the irradiation requirements of DUPIC fuel at HANARO, iii) performance verification in-core behavior at HANARO of DUPIC simulated fuel, iv) establishing and improvement the data base for DUPIC fuel performance verification codes, and v) establishing the irradiation procedure in HANARO for DUPIC fuel. The post-irradiation examination performed are {gamma}-scanning, profilometry, density, hardness, observation the microstructure and fission product distribution by optical microscope and electron probe microanalyser (EPMA)

  15. Irradiated cocoa beans

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, R.; Tesh, J.M.

    1982-11-01

    Groups of 40 male and 40 female CD rats were fed powdered rodent diet containing 25% (w/w) of either non-irradiated, irradiated or fumigated cocoa beans. The diets were supplemented with certain essential dietary constituents designed to satisfy normal nutritional requirements. An additional 40 male and 40 female rats received basal rodent diet alone (ground) and acted as an untreated control. After 70 days of treatment, 15 male and 15 female rats from each group were used to assess reproductive function of the F/sub 0/ animals and growth and development of the F/sub 1/ offspring up to weaning; the remaining animals were killed after 91 days of treatment.

  16. Irradiated brown dwarfs

    CERN Document Server

    Casewell, S L; Lawrie, K A; Maxted, P F L; Dobbie, P D; Napiwotzki, R

    2014-01-01

    We have observed the post common envelope binary WD0137-349 in the near infrared $J$, $H$ and $K$ bands and have determined that the photometry varies on the system period (116 min). The amplitude of the variability increases with increasing wavelength, indicating that the brown dwarf in the system is likely being irradiated by its 16500 K white dwarf companion. The effect of the (primarily) UV irradiation on the brown dwarf atmosphere is unknown, but it is possible that stratospheric hazes are formed. It is also possible that the brown dwarf (an L-T transition object) itself is variable due to patchy cloud cover. Both these scenarios are discussed, and suggestions for further study are made.

  17. In vivo dosimetry of high-dose fractionated irradiation in an experimental set-up with rats

    Energy Technology Data Exchange (ETDEWEB)

    Fortan, L.; Van Hecke, H.; Van Duyse, B.; De Neve, W.; De Meerleer, B. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Pattyn, P.; Van Renthergem, K. [Ghent University (Belgium). Dept. of Surgery

    1995-12-01

    The feasibility to irradiate a limited section of a rat abdomen with well-defined edges was assessed. Because of the relative small volume involved, in vivo dosimetry with TLDs was necessary in providing us information about the accuracy of the irradiation method. Three to five days prior to the start of the radiotherapy treatment, two plastic strips - each containing a TLD-dosimeter (Harshaw TLD10 LiF rods, 1 mm dia x 6 mm) sealed in polyethylene tubing, and a lead bean - were implanted in the rat abdomen. The plastic strips made a closed loop around the bowel, through the mesenterium, and were fixed with a single stitch on the inner abdominal wall. One loop was made in the hepatic area; another was made in the lower abdomen, around the rectosigmoid. Conscious animals were irradiated using a purpose-build plexi-holder, with rear legs immobilised to avoid longitudinal movements. The implanted lead beans enabled us to simulate the rat prior to each radiation session. This way, the radiation field could be set up individually for each rat, in such way that the rectosigmoid area received full dose and the hepatic area received no irradiation dose at all. Irradiation was carried out, using 5 MV photons of a linear accelerator. Fifteen animals per group were irradiated according a conventional (2.0 Gy / fraction; 5 fractions / week) or a hyperfractionated (1.6 Gy / fraction; 2 daily fractions; 5 days / week) schedule, with different total doses. Prior to implantation, TLDs were individually calibrated and checked for stability. After removal from the abdomen . TLDs were tested again for accuracy. TLDs with an unacceptable read-out curve were rejected (about 2 to 4 TLDs per group of 15). The obtained accumulated doses - as determined by TLD read-outs-were comparable to the theoretical doses, indicating that fractionated radiation of small fields, with well defined mark off, in rats is feasible.

  18. A study on measurement of NO concentrations in laminar premixed CH{sub 4}/O{sub 2}/N{sub 2} flames by LIF

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.W. [Kyung Hee University Graduate School, Seoul (Korea); Jin, S.H.; Kim, G.S. [Korea Institute of Industrial Technology, Chonan (Korea); Park, K.S. [Kyung Hee University, Seoul (Korea)

    2000-11-01

    In this study, quantitative nitric oxide concentration distributions are investigated in the post-flame zone of laminar premixed CH{sub 4}/O{sub 2}/N{sub 2} flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different equivalence ratios varying from 0.8 {approx} 1.4, and flow rate is fixed as 5 slpm. The No A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interferences from Rayleigh scattering and O{sub 2} fluorescence. NO concentration is rised when equivalence ratios increase at different vertical distances form nozzle tip. In any case, the maximum NO concentration reaches the maximum in reaction zone. (author). 11 refs., 9 figs., 1 tab.

  19. Quantum dynamical simulation of the scattering of Ar from a frozen LiF(100) surface based on a first principles interaction potential

    Energy Technology Data Exchange (ETDEWEB)

    Azuri, Asaf; Pollak, Eli, E-mail: eli.pollak@weizmann.ac.il [Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovoth (Israel)

    2015-07-07

    In-plane two and three dimensional diffraction patterns are computed for the vertical scattering of an Ar atom from a frozen LiF(100) surface. Suitable collimation of the incoming wavepacket serves to reveal the quantum mechanical diffraction. The interaction potential is based on a fit to an ab initio potential calculated using density functional theory with dispersion corrections. Due to the potential coupling found between the two horizontal surface directions, there are noticeable differences between the quantum angular distributions computed for two and three dimensional scattering. The quantum results are compared to analogous classical Wigner computations on the same surface and with the same conditions. The classical dynamics largely provides the envelope for the quantum diffractive scattering. The classical results also show that the corrugation along the [110] direction of the surface is smaller than along the [100] direction, in qualitative agreement with experimental observations of unimodal and bimodal scattering for the [110] and [100] directions, respectively.

  20. Image and Radiation Power Analysis Techniques for Determining Electron temperature, Liner Areal Density, and Radiated Energy in MagLIF Experiments

    Science.gov (United States)

    Evans, Matthew; Knapp, Patrick; Gomez, Matthew; Hansen, Stephanie; McBride, Ryan; MacPherson, L. Armon; Gourdain, Pierre

    2016-10-01

    We describe techniques developed to analyze filtered Time Integrated Pinhole Camera (TIPC) images to determine the axially resolved electron temperature and liner areal density at stagnation in MagLIF experiments conducted on the Z machine at Sandia National Laboratories. X-ray power detectors are analyzed to determine the absolute radiated energy. The TIPC images are co-registered using intensity based similarities. This technique is shown to provide accurate registration without the use of fiducial markings. A filtered 6-channel PCD array was used to record the radiated power at photon energies >1 keV. A model for the x-ray emission is used with the data set to perform Bayesian parameter estimation to simultaneously determine the electron temperature, liner areal density and x-ray yield with uncertainties via χ2 minimization.

  1. Detector for the FSD Fourier-Diffractometer Based on ZnS(Ag)/^{6}LiF Scintillation Screen and Wavelength Shifting Fibers Readout

    CERN Document Server

    Kuzmin, E S; Bokuchava, G D; Zhuk, V V; Kudryashov, V A; Buklin, A P; Trounov, V A

    2001-01-01

    At the IBR-2 pulsed reactor (FLNP, JINR, Dubna), a specialized time-of-flight instrument Fourier-Stress-Diffractometer (FSD) intended for the measurement of internal steresses in bulk samples by using high-resolution neutron diffraction is under construction. One of the main components of the diffractometer is a new-type detector with combined electronic - geometrical focusing uniting a large solid angle and a small geometry contribution to the instrumental resolution. The first two modules of the detector, based on scintillation screen ZnS(Ag)/^{6}LiF with wavelength shifting fibers readout have been developed and tested. The design of the detector and associated electronics are described. The method of time focusing surface approximation, using the screen flexibility is proposed. Characteristics of tested modules in comparison with a detector of previous generation are presented and advantages of new detector design for high-resolution diffractometry are discussed.

  2. Regulation of food irradiation and detection of irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, P.B. [Institute of Geological and Nuclear Sciences, Lower Hutt (New Zealand)

    1998-12-31

    The main international standards for irradiated foods are those produced by the Codex Alimentarius Commission. The international regulatory environment is now favourable towards irradiated foods. Most countries still regulate on a food-by-food, case-by-case basis. However in Asia there is movement towards a Harmonised Regulation for Irradiated Foods. The WHO believes that irradiated foods may be safely irradiated at any dose above 10 kGy. This may lead to the Codex maximum dose being raised or abandoned. If this occurs there are opportunities to produce shelf-stable foods in lightweight packaging that last for years at room temperature. Detection methods for irradiated foods are now available and may assist to reassure consumers that labelling regulations can be enforced. (author)

  3. ATF Neutron Irradiation Program Irradiation Vehicle Design Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Cetiner, N. O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Petrie, Christian M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Smith, Kurt R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; McDuffee, J. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to Japan. This report discusses the conceptual design, the development and irradiation of the test vehicles.

  4. Gemstone dedicated gamma irradiation development

    Energy Technology Data Exchange (ETDEWEB)

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  5. OH-LIF measurement of H2/O2/N2 flames in a micro flow reactor with a controlled temperature profile

    Science.gov (United States)

    Shimizu, T.; Nakamura, H.; Tezuka, T.; Hasegawa, S.; Maruta, K.

    2014-11-01

    This paper presents combustion and ignition characteristic of H2/O2/N2 flames in a micro flow reactor with a controlled temperature profile. OH-LIF measurement was conducted to capture flame images. Flame responses were investigated for variable inlet flow velocity, U, and equivalence ratio, phi. Three kinds of flame responses were experimentally observed for the inlet flow velocities: stable flat flames (normal flames) in the high inlet flow velocity regime; unstable flames called Flames with Repetitive Extinction and Ignition (FREI) in the intermediate flow velocity regime; and stable weak flames in the low flow velocity regime, at phi = 0.6, 1.0 and 1.2. On the other hand, weak flame was not observed at phi = 3.0 by OH-LIF measurement. Computational OH mole fractions showed lower level at the rich conditions than those at stoichiometric and lean conditions. To examine this response of OH signal to equivalence ratio, rate of production analysis was conducted and four kinds of major contributed reaction for OH production: R3(O + H2 H + OH); R38(H + O2 O + OH); R46(H + HO2 2OH); and R86(2OH O + H2O), were found. Three reactions among them, R3, R38 and R46, did not showed significant difference in rate of OH production for different equivalence ratios. On the other hand, rate of OH production from R86 at phi = 3.0 was extremely lower than those at phi = 0.6 and 1.0. Therefore, R86 was considered to be a key reaction for the reduction of the OH production at phi = 3.0.

  6. Review of the dose-to-water energy dependence of alanine and lithium formate EPR dosimeters and LiF TL-dosimeters - Comparison with Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Waldeland, Einar, E-mail: einar.waldeland@oslo-universitetssykehus.no [Department of Medical Physics, Oslo University Hospital, Norwegian Radium Hospital, P.O. Box 4953 Nydalen, N-0424 Oslo (Norway); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Malinen, Eirik [Department of Medical Physics, Oslo University Hospital, The Norwegian Radium Hospital, P.O. Box 4953 Nydalen, N-0424 Oslo (Norway); Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)

    2011-09-15

    The dose-to-water energy dependence may be defined as the dosimeter reading per absorbed dose to water for a given radiation beam relative to that for {sup 60}Co {gamma} rays. The purpose of this work was to review the literature on the dose-to-water energy dependence of lithium formate and alanine EPR dosimeters and LiF:Mg,Ti TL-dosimeters for clinical beam qualities and to compare the findings with Monte Carlo simulations. Monte Carlo simulations of the energy dependence of lithium formate and alanine EPR dosimeters and LiF:Mg,Ti TL-dosimeters were performed using the EGSnrc code. The following common clinical radiation qualities were applied: 4-24 MV photons, 4-20 MeV electrons, 50-200 kV{sub p} X-rays, {sup 192}Ir {gamma} rays, and {sup 60}Co {gamma} rays as the reference. All dosimeter materials showed measured and Monte Carlo simulated energy responses around unity for MV photons, electrons and {sup 192}Ir {gamma} rays, except LiF TL-dosimeters which showed an average underresponse of approximately 3% for electrons. For medium energy X-rays (50-200 kV{sub p}), LiF displayed an increasing overresponse with decreasing energy to a maximum of about 40% for 50 kV{sub p} X-rays. The two EPR dosimeter materials showed decreasing energy response with decreasing X-ray energy, but lithium formate was less dependent on energy than alanine. Comparisons between Monte Carlo simulations and measurements revealed some deviations for medium energy X-rays, which may be due to LET-effects caused by low energy electrons. In conclusion, lithium formate is the dosimeter material with the lowest energy dependence over a wide range of clinically relevant radiation qualities, which clearly is advantageous for accurate dosimetry.

  7. Concentration quenching of the emission of F{sup +}{sub 3} and F{sub 2} color centers in LiF

    Energy Technology Data Exchange (ETDEWEB)

    Baldacchini, G.; Menchini, F.; Montereali, R.M.; Messina, G.; Pace, A. [ENEA, Divisione Fisica Applicata, Centro Ricerche Frascati, Frascati, RM (Italy)

    2000-07-01

    The emission efficiency of F{sup +}{sub 3} and F{sub 2} centers as a function of their concentration has been investigated in LiF crystals colored at Rt with 3 MeV electrons. From a careful investigation of their absorption and emission spectra from 80 K to Rt, it was discovered that the emission efficiency h of both F{sup +}{sub 3} and F{sub 2} defects is constant up to {approx} 10{sup 1}6 centers/cm{sup 3}. When increasing the concentration up to 10{sup 1}8 centers/cm{sup 3}, h is decreasing slightly for the F{sub 2} centers and considerably for the F{sup +}{sub 3} ones. Moreover, the efficiency of the latter centers further decreases by increasing the temperature. A thermally activated process is taking place, while the F{sub 2} and other aggregate defects play an important role. [Italian] Si e' qui presa in esame l'efficienza quantica di emissione dei centri F{sup +}{sub 3} e F{sub 2} in funzione della loro concentrazione in cristalli di LiF colorati con elettroni da 3 MeV. Dall'analisi degli assorbimenti e delle luminescenze di tali centri, da 80 K a RT, si e' ricavato che la loro efficienza h e' costante fino a concentrazioni di {approx} 10{sup 1}6 centri/cm{sup 3}, mentre oltre i 10{sup 1}6 centri/cm{sup 3} h decresce, leggermente per i centri F{sub 2} e sensibilmente per gli F{sup +}{sub 3}. Inoltre, l'efficienza di questi ultimi difetti decresce ulteriormente all'aumentare della temperatura. Si suppone l'esistenza di un processo attivato termicamente, mentre i centri F{sub 2} ed altri difetti aggregati svolgono un ruolo importante.

  8. Measurement of neutron energy spectra and neutron dose rates from {sup 7}Li(p,n){sup 7}Be reaction induced on thin LiF target

    Energy Technology Data Exchange (ETDEWEB)

    Atanackovic, Jovica, E-mail: atanacjz@gmail.com [Ontario Power Generation, Whitby, ON, Canada L1N 9E3 (Canada); Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Canada K0J 1J0 (Canada); Matysiak, Witold [University of Florida Proton Therapy Institute, Jacksonville, FL 32206 (United States); Dubeau, Jacques; Witharana, Sampath [DETEC, Gatineau, QC, Canada J8T 4J1 (Canada); Waker, Anthony [University of Ontario Institute of Technology, Oshawa, ON, Canada L1H 7K4 (Canada)

    2015-02-21

    The measurements of neutron energy spectra and neutron dose rates were performed using the KN Van de Graaff accelerator, located at the McMaster University Accelerator Laboratory (MAL). Protons were accelerated on the thin lithium fluoride (LiF) target and produced mono-energetic neutrons which were measured using three different spectrometers: Bonner Sphere Spectrometer (BSS), Nested Neutron Spectrometer (NNS), and Rotational Proton Recoil Spectrometer (ROSPEC). The purpose of this work is (1) measurement and quantification of low energy accelerator neutron fields in terms of neutron fluence and dose, (2) comparison of results obtained by three different instruments, (3) comparison of measurements with Monte Carlo simulations based on theoretical neutron yields from {sup 7}Li(p,n){sup 7}Be nuclear reaction, and (4) comparison of results obtained using different neutron spectral unfolding methods. The nominal thickness of the LiF target used in the experiment was 50μg/cm{sup 2}, which corresponds to the linear thickness of 0.19μm and results in approximately 6 keV energy loss for the proton energies used in the experiment (2.2, 2.3, 2.4 and 2.5 MeV). For each of the proton energies, neutron fluence per incident proton charge was measured and several dosimetric quantities of interest in radiation protection were derived. In addition, theoretical neutron yield calculations together with the results of Monte Carlo (MCNP) modeling of the neutron spectra are reported. Consistent neutron fluence spectra were obtained with three detectors and good agreement was observed between theoretically calculated and measured neutron fluences and derived dosimetric quantities for investigated proton energies at 2.3, 2.4 and 2.5 MeV. In the case of 2.2 MeV, some plausibly explainable discrepancies were observed.

  9. Standoff detection of bioaerosols over wide area using a newly developed sensor combining a cloud mapper and a spectrometric LIF lidar

    Science.gov (United States)

    Buteau, Sylvie; Simard, Jean-Robert; Roy, Gilles; Lahaie, Pierre; Nadeau, Denis; Mathieu, Pierre

    2013-10-01

    A standoff sensor called BioSense was developed to demonstrate the capacity to map, track and classify bioaerosol clouds from a distant range and over wide area. The concept of the system is based on a two steps dynamic surveillance: 1) cloud detection using an infrared (IR) scanning cloud mapper and 2) cloud classification based on a staring ultraviolet (UV) Laser Induced Fluorescence (LIF) interrogation. The system can be operated either in an automatic surveillance mode or using manual intervention. The automatic surveillance operation includes several steps: mission planning, sensor deployment, background monitoring, surveillance, cloud detection, classification and finally alarm generation based on the classification result. One of the main challenges is the classification step which relies on a spectrally resolved UV LIF signature library. The construction of this library relies currently on in-chamber releases of various materials that are simultaneously characterized with the standoff sensor and referenced with point sensors such as Aerodynamic Particle Sizer® (APS). The system was tested at three different locations in order to evaluate its capacity to operate in diverse types of surroundings and various environmental conditions. The system showed generally good performances even though the troubleshooting of the system was not completed before initiating the Test and Evaluation (T&E) process. The standoff system performances appeared to be highly dependent on the type of challenges, on the climatic conditions and on the period of day. The real-time results combined with the experience acquired during the 2012 T & E allowed to identify future ameliorations and investigation avenues.

  10. Craniospinal irradiation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scarlatescu, Ioana, E-mail: scarlatescuioana@gmail.com; Avram, Calin N. [Faculty of Physics, West University of Timisoara, Bd. V. Parvan 4, 300223 Timisoara (Romania); Virag, Vasile [County Hospital “Gavril Curteanu” - Oradea (Romania)

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  11. Irradiated stars with convective envelopes

    CERN Document Server

    Lucy, L B

    2016-01-01

    The structure of low-mass stars irradiated by a close companion is considered. Irradiation modifies the surface boundary conditions and thereby also the adiabatic constants of their outer convection zones. This then changes the models' radii and luminosities. For short-period M dwarf binaries with components of similar mass, the radius inflation due to their mutual irradiation is found to be < 0.4%. This is an order of magnitude too small to explain the anomalous radii found for such binaries. Although stronger irradiation of an M dwarf results in a monotonically increasing radius, a saturation effect limits the inflation to < 5%.

  12. International Developments of Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940`s: discovery of principles of food irradiation; 1950`s: initiation of research in advanced countries; 1960`s: research and development were intensified in some advanced and developing countries; 1970`s: proof of wholesomeness of irradiated foods; 1980`s: establishment of national regulations; 1990`s: commercialization and international trade. (Author)

  13. Irradiation of northwest agricultural products

    Science.gov (United States)

    Eakin, D. E.; Tingey, G. I.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect ocntrol procedures are developed and followed. Due to the recognized potential benefits of irradiation, this program was conducted to evaluate the benefits of using irradiation on Northwest agricultural products. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  14. Spatially resolved analyses of uranium species using a coupled system made up of confocal laser-scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS); Ortsaufgeloeste Analyse von Uranspezies mittels einem Gekoppelten System aus Konfokaler Laser-Scanning Mikroskopie (CLSM) und Laser Induzierter Fluoreszenzspektroskopie (LIFS)

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, S. [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Grossmann, K.; Arnold, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V. (Germany). Inst. fuer Ressourcenoekologie

    2014-01-15

    The fluorescent properties of uranium when excited by UV light are used increasingly for spectroscope analyses of uranium species within watery samples. Here, alongside the fluorescent properties of the hexavalent oxidation phases, the tetra and pentavalent oxidation phases also play an increasingly important role. The detection of fluorescent emission spectrums on solid and biological samples using (time-resolved) laser induced fluorescence spectroscopy (TRLFS or LIFS respectively) has, however, the disadvantage that no statements regarding the spatial localisation of the uranium can be made. However, particularly in complex, biological samples, such statements on the localisation of the uranium enrichment in the sample are desired, in order to e.g. be able to distinguish between intra and extra-cellular uranium bonds. The fluorescent properties of uranium (VI) compounds and minerals can also be used to detect their localisation within complex samples. So the application of fluorescent microscopic methods represents one possibility to localise and visualise uranium precipitates and enrichments in biological samples, such as biofilms or cells. The confocal laser-scanning microscopy (CLSM) is especially well suited to this purpose. Coupling confocal laser-scanning microscopy (CLSM) with laser induced fluorescence spectroscopy (LIFS) makes it possible to localise and visualise fluorescent signals spatially and three-dimensionally, while at the same time being able to detect spatially resolved, fluorescent-spectroscopic data. This technology is characterised by relatively low detection limits from up to 1.10{sup -6} M for uranium (VI) compounds within the confocal volume. (orig.)

  15. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  16. Wholesomeness of irradiated food

    Science.gov (United States)

    Ehlermann, Dieter A. E.

    2016-12-01

    Just with the emergence of the idea to treat food by ionizing radiation, the concerns were voiced whether it would be safe to consume such food. Now, we look back on more than hundred years of research into the 'wholesomeness', a terminology developed during those efforts. This review will cover the many questions which had been raised, explaining the most relevant ones in some detail; it will also give place to the concerns and elucidate their scientific relevance and background. There has never been any other method of food processing studied in such depth and in such detail as food irradiation. The conclusion based on science is: Consumption of any food treated at any high dose is safe, as long as the food remains palatable. This conclusion has been adopted by WHO, also by international and national bodies. Finally, this finding has also been adopted by Codex Alimentarius in 2003, the international standard for food. However, this conclusion has not been adopted and included at its full extent in most national regulations. As the literature about wholesomeness of irradiated food is abundant, this review will use only a few, most relevant references, which will guide the reader to further reading.

  17. Consumer acceptance of irradiated poultry.

    Science.gov (United States)

    Hashim, I B; Resurreccion, A V; McWatters, K H

    1995-08-01

    A simulated supermarket setting (SSS) test was conducted to determine whether consumers (n = 126) would purchase irradiated poultry products, and the effects of marketing strategies on consumer purchase of irradiated poultry products. Consumer preference for irradiated poultry was likewise determined using a home-use test. A slide program was the most effective educational strategy in changing consumers' purchase behavior. The number of participants who purchased irradiated boneless, skinless breasts and irradiated thighs after the educational program increased significantly from 59.5 and 61.9% to 83.3 and 85.7% for the breasts and thighs, respectively. Using a label or poster did not increase the number of participants who bought irradiated poultry products. About 84% of the participants consider it either "somewhat necessary" or "very necessary" to irradiate raw chicken and would like all chicken that was served in restaurants or fast food places to be irradiated. Fifty-eight percent of the participants would always buy irradiated chicken if available, and an additional 27% would buy it sometimes. About 44% of the participants were willing to pay the same price for irradiated chicken as for nonirradiated. About 42% of participants were willing to pay 5% or more than what they were currently paying for nonirradiated chicken. Seventy-three percent or more of consumers who participated in the home-use test (n = 74) gave the color, appearance, and aroma of the raw poultry products a minimum rating of 7 (= like moderately). After consumers participated in a home-use test, 84 and 88% selected irradiated thighs and breasts, respectively, over nonirradiated in a second SSS test.

  18. Whole-body dose and energy measurements in radiotherapy by a combination of LiF:Mg,Cu,P and LiF:Mg,Ti.

    Science.gov (United States)

    Hauri, Pascal; Schneider, Uwe

    2017-08-11

    Long-term survivors of cancer who were treated with radiotherapy are at risk of a radiation-induced tumor. Hence, it is important to model the out-of-field dose resulting from a cancer treatment. These models have to be verified with measurements, due to the small size, the high sensitivity to ionizing radiation and the tissue-equivalent composition, LiF thermoluminescence dosimeters (TLD) are well-suited for out-of-field dose measurements. However, the photon energy variation of the stray dose leads to systematic dose errors caused by the variation in response with radiation energy of the TLDs. We present a dosimeter which automatically corrects for the energy variation of the measured photons by combining LiF:Mg,Ti (TLD100) and LiF:Mg,Cu,P (TLD100H) chips. The response with radiation energy of TLD100 and TLD100H compared to (60)Co was taken from the literature. For the measurement, a TLD100H was placed on top of a TLD100 chip. The dose ratio between the TLD100 and TLD100H, combined with the ratio of the response curves was used to determine the mean energy. With the energy, the individual correction factors for TLD100 and TLD100H could be found. The accuracy in determining the in- and out-of-field dose for a nominal beam energy of 6MV using the double-TLD unit was evaluated by an end-to-end measurement. Furthermore, published Monte Carlo (M.C.) simulations of the mean photon energy for brachytherapy sources, stray radiation of a treatment machine and cone beam CT (CBCT) were compared to the measured mean energies. Finally, the photon energy distribution in an Alderson phantom was measured for different treatment techniques applied with a linear accelerator. Additionally, a treatment plan was measured with a cobalt machine combined with an MRI. For external radiotherapy, the presented double-TLD unit showed a relative type A uncertainty in doses of -1%±2% at the two standard deviation level compared to an ionization chamber. The type A uncertainty in dose was in

  19. Sensorial evaluation of irradiated mangoes

    Energy Technology Data Exchange (ETDEWEB)

    Broisler, Paula Olhe; Cruz, Juliana Nunes da; Sabato, Susy Frey [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: paulabroisler@hotmail.com; juliananc@ig.com.br; sfsabato@ipen.br

    2007-07-01

    Mango (Mangifera indica L.) is a tropical fruit of great economical relevance in the world, mainly for tropical countries like Brazil. It consists in the second tropical fruit more important grown in the world. On the other hand it is a very perishable fruit and its delivery to distant points is restricted due to short shelf life at environmental temperature. Food irradiation process is applied to fruits for their preservation, once it promotes disinfestation and even maturation retard, among other mechanisms. The Brazilian legislation permits the food irradiation and does not restrict the doses to be delivered. In order to verify eventual changes, sensorial evaluation is very important to study how irradiation affects the quality of the fruit and its acceptability. Mangoes were irradiated in a Cobalto-60 source, from the Radiation Technology Center, CTR, of IPEN/CNEN-SP at doses 0,5 kGy e 0,75 kGy. The sensorial evaluation was measured through Acceptance Test where irradiated samples were offered together with control sample to the tasters who answered their perception through hedonic scale. The parameters Color, Odor, Flavor and Texture were analyzed. Statistical analysis showed that only Odor parameter was different from control (sample irradiated at 0.5 kGy). Few tasters indicated that irradiated mangoes had fewer odors in relation to non-irradiated samples. (author)

  20. World trend of food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kooij, J.G. van

    1984-01-01

    Over the past fifteen years several policies and programmes have been developed in the field of food irradiation at the national level and by international organizations concerned, which aim at the general acceptance and practical implementation of food irradiation through rigorous investigations of the wholesomeness, the technological and economic feasibility, and the regulatory aspects of this process. This paper reviews international aspects of the standardization of food irradiation, national regulatory aspects of food irradiation, general remarks on the acceptance of Codex General Standards for irradiated foods, and specific remarks on the Codex General Standard for irradiated foods. An overall average dose for all foods, which was formulated in 1980 by a Joint FAO/IAEA/WHO Expert Committee, is 10 kGy. This 10 kGy is not a level above which irradiated foods become unsafe, rather, it is a level at or below which safety has been established. Irradiation dose is divided into low-dose (up to about 1 kGy) and medium-dose (about 1-10 kGy). Future outlook and needs are discussed.

  1. Food irradiation and bacterial toxins

    Energy Technology Data Exchange (ETDEWEB)

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-07-04

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods.

  2. Effect of LiF on Capacitance of OLEDs%LiF作电子注入缓冲层对有机电致发光器件电容的影响

    Institute of Scientific and Technical Information of China (English)

    李颖弢; 刘肃; 王方聪; 张春林; 岳红菊

    2007-01-01

    Numerical methods have been used to analyze the contribution of LiF layer which is inserted between the cathode and the electron-transporting layer in organic light emitting devices (OLEDs). The LiF as the electron injection buffer layer can improve the performance of the OLEDs, including reducing the cut-in voltage, increasing the current and emitting luminance. This work fabricates two different kinds of devices A and B with structures of Indium Tin Oxide (ITO)/tris-(8-hydroxyquinoline) aluminum (Alq3)/Al and ITO/Alq3/LiF/Al, using the C-V characteristic to analyze the roles of LiF in OLEDs and finding the capacitance of the device A and B is 72 500 pF and 12 500 pF, respectively. At the same time, this paper interprets why LiF could reduce the capacitance and the power consumption of the OLEDs from the correct point of view. It shows that the LiF layer improves the performance of the OLEDs and saves the energy sources, resulting in the change of the capacitance of the devices.%已经有多种方法分析了LiF作为电子注入缓冲层对有机电致发光器件的影响,用LiF/Al双层阴极和发光层Alq3制成的有机电致发光器件(OLED), 可以降低器件的开启电压,提高器件的发光效率、发光亮度.文章主要对OLEDs (A): Al/Alq3/ITO和(B): Al /LiF(1nm)/Alq3/ITO的C-V特性进行了研究,当在阴极和发光层Alq3之间加上1 nm厚的LiF层作为电子注入缓冲层以后,器件的电容由不加LiF时的72 500 pF减小到12 500 pF,由于电容的减小,有效地降低了器件的功耗,进而提高了器件的寿命,节约了能源,进一步改善了器件的性能.

  3. Commercial implementation of food irradiation

    Science.gov (United States)

    Welt, M. A.

    In July 1981, the first specifically designed multi-purpose irradiation facility for food irradiation was put into service by the Radiation Technology, Inc. subsidiary Process Technology, Inc. in West Memphis, Arkansas. The operational experience gained, resulted in an enhanced design which was put into commercial service in Haw River, North Carolina, by another subsidiary, Process Technology (N.C.), Inc. in October 1983. These facilities have enabled the food industry to assess the commercial viability of food irradiation. Further impetus towards commercialization of food irradiation was gained in March 1981 with the filing in the Federal Register, by the FDA, of an Advanced Proposed Notice of Rulemaking for Food Irradiation. Two years later in July 1983, the FDA approved the first food additive regulation involving food irradiation in nineteen years, when they approved the Radiation Technology, Inc. petition calling for the sanitization of spices, onion powder and garlic powder at a maximum dosage of 10 kGy. Since obtaining the spice irradiation approval, the FDA has accepted four additional petitions for filing in the Federal Register. One of the petitions which extended spice irradiation to include insect disinfestation has issued into a regulation while the remaining petitions covering the sanitization of herbs, spice blends, vegetable seasonings and dry powdery enzymes as well as the petition to irradiate hog carcasses and pork products for trichinae control at 1 kGy, are expected to issue either before the end of 1984 or early in 1985. More recently, food irradiation advocates in the United States received another vote of confidence by the announcement that a joint venture food irradiation facility to be constructed in Hawaii by Radiation Technology, is backed by a contractual committment for the processing of 40 million pounds of produce per year. Another step was taken when the Port of Salem, New Jersey announced that the Radiation Technology Model RT-4104

  4. Irradiation of fresh fish

    Science.gov (United States)

    Yueh-jen, Yen; Jin-lai, Zhou; Shao-chun, Lai

    Occasionally, in China, marine products can not be provided for the markets in good quality, for during the time when they are being transported from the sea port to inland towns or even at the time when they are unloaded from the ship, they are beginning to spoil. Obviously, it is very important that appropiate measures should be taken to prevent them from decay. Our study has proved that the shelf life of fresh Flatfish (Cynoglossue robustus) and Silvery pomfret (stromateoides argenteus), which, packed in sealed containers, are irradiated by 1.5 kGy, 2.2 kGy and 3.0 kGy, can be stored for about 13-26 days at 3° - 5° C.

  5. Consumer acceptance of irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/ IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    There was a widely held opinion during the 1970`s and 1980`s that consumers would be reluctant to purchase irradiated food, as it was perceived that consumers would confuse irradiated food with food contaminated by radionuclides. Indeed, a number of consumer attitude surveys conducted in several western countries during these two decades demonstrated that the concerns of consumers on irradiated food varied from very concerned to seriously concerned.This paper attempts to review parameters conducting in measuring consumer acceptance of irradiated food during the past three decades and to project the trends on this subject. It is believed that important lessons learned from past studies will guide further efforts to market irradiated food with wide consumer acceptance in the future. (Author)

  6. Pallet irradiators for food processing

    Science.gov (United States)

    McKinnon, R. G.; Chu, R. D. H.

    This paper looks at the various design concepts for the irradiation processing of food products, with particular emphasis on handling the products on pallets. Pallets appear to offer the most attractive method for handling foods from many considerations. Products are transported on pallets. Warehouse space is commonly designed for pallet storage and, if products are already palletized before and after irradiation, then labour could be saved by irradiating on pallets. This is also an advantage for equipment operation since a larger carrier volume means lower operation speeds. Different pallet irradiator design concepts are examined and their suitability for several applications are discussed. For example, low product holdup for fast turn around will be a consideration for those operating an irradiation "service" business; others may require a very large source where efficiency is the primary requirement and this will not be consistent with low holdup. The radiation performance characteristics and processing costs of these machines are discussed.

  7. Late sequelae of superficial irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hood, I.C.; Young, J.E.

    1984-10-01

    Superficial irradiation results in well recognized late sequelae including not only sclerosis and atrophy of skin and subcutaneous tissue, but also the development of benign and malignant tumors of skin and adjacent structures. The long latency between irradiation and its late effects allowed the early uncontrolled use of radiation treatment for benign conditions. The subsequent recognition of the causal relationship between tumors and previous irradiation has restricted its use to more appropriate purposes, although it is possible that it is still overused in some areas of dermatologic practice. Clinicians need to be aware of the time interval between irradiation and the development of its late sequelae, and the incidence of these sequelae. Appropriate irradiation exposure history should be a part of the evaluation of every patient.

  8. Using submicron-resolution LiF crystal and film x-ray detectors for the near and far fields in-situ characterization of soft x-ray laser beams

    Science.gov (United States)

    Pikuz, Tatiana A.; Faenov, Anatoly Y.; Fukuda, Yuji; Kato, Yoshiaki; Kawachi, Tetsuya; Kando, Masaki

    2012-01-01

    Review of results, obtained by using recently proposed new imaging detector, based on formation of color centers in LiF crystal and LiF film, for in situ high performance measurements of near-field and far-field properties of soft X-ray lasers (SXRL) beams is presented. Experiments have been carried out with laser-driven transient-collision plasma SXRL and free electron SXRL beams. It was demonstrated that due to favorable combination of high spatial resolution, high dynamic range and wide field of view this technique allows measuring not only intensity distribution across the full beam and in local areas, but also permits to evaluate coherence and spectral distribution of radiation across the beam. Experimental diffraction patterns in the images of periodical structures are analyzed by comparison with the modeled ones in the last case. The estimated accuracy of measurements is between 10-20%.

  9. Digital signal processing for a thermal neutron detector using ZnS(Ag):{sup 6}LiF scintillating layers read out with WLS fibers and SiPMs

    Energy Technology Data Exchange (ETDEWEB)

    Mosset, J.-B., E-mail: jean-baptiste.mosset@psi.ch; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2016-07-11

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):{sup 6}LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC{sup 4} filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC{sup 4} filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach. - Highlights: • Application of digital signal processing for a SiPM-based ZnS:6LiF neutron detector. • Optimisation of detector performances with 3 different digital filters. • Comparison with detector performances with a full analog signal processing.

  10. Phytosanitary irradiation - Development and application

    Science.gov (United States)

    Hallman, Guy J.; Loaharanu, Paisan

    2016-12-01

    Phytosanitary irradiation, the use of ionizing radiation to disinfest traded agricultural commodities of regulated pests, is a growing use of food irradiation that has great continued potential for increase in commercial application. In 2015 approximately 25,000 t of fresh fruits and vegetables were irradiated globally for phytosanitary purposes. Phytosanitary irradiation has resulted in a paradigm shift in phytosanitation in that the final burden of proof of efficacy of the treatment has shifted from no live pests upon inspection at a port of entry (as for all previous phytosanitary treatments) to total dependence on certification that the treatment for target pests is based on adequate science and is commercially conducted and protected from post-treatment infestation. In this regard phytosanitary irradiation is managed more like a hazard analysis and critical control point (HACCP) approach more consistent with food safety than phytosanitation. Thus, phytosanitary irradiation offers a more complete and rigorous methodology for safeguarding than other phytosanitary measures. The role of different organizations in achieving commercial application of phytosanitary irradiation is discussed as well as future issues and applications, including new generic doses.

  11. Modelling of a targeted nanotherapeutic ‘stroma’ to deliver the cytokine LIF, or XAV939, a potent inhibitor of Wnt–β-catenin signalling, for use in human fetal dopaminergic grafts in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Jing-Wei Zhao

    2014-10-01

    Full Text Available The endogenous reparative capacity of the adult human brain is low, and chronic neurodegenerative disorders of the central nervous system represent one of the greatest areas of unmet clinical need in the developing world. Novel therapeutic strategies to treat them include: (i growth factor delivery to boost endogenous repair and (ii replacement cell therapy, including replacing dopaminergic neurons to treat Parkinson’s disease (PD. However, these approaches are restricted not only by rapid degradation of growth factors, but also by the limited availability of cells for transplant and the poor survival of implanted cells that lack the necessary stromal support. We therefore hypothesised that provision of a transient artificial stroma for paracrine delivery of pro-survival factors could overcome both of these issues. Using leukaemia inhibitory factor (LIF – a proneural, reparative cytokine – formulated as target-specific poly(lactic-co-glycolic acid (PLGA nano-particles (LIF-nano-stroma, we discovered that attachment of LIF-nano-stroma to freshly isolated fetal dopaminergic cells improved their survival fourfold: furthermore, in vivo, the number of surviving human fetal dopaminergic cells tended to be higher at 3 months after grafting into the striatum of nude rats, compared with controls treated with empty nanoparticles. In addition, we also analysed the effect of a novel nano-stroma incorporating XAV939 (XAV, a potent inhibitor of the developmentally important Wnt–β-catenin signalling pathway, to investigate whether it could also promote the survival and differentiation of human fetal dopaminergic precursors; we found that the numbers of both tyrosine-hydroxylase-positive neurons (a marker of dopaminergic neurons and total neurons were increased. This is the first demonstration that LIF-nano-stroma and XAV-nano-stroma each have pro-survival effects on human dopaminergic neurons, with potential value for target-specific modulation of

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

    Science.gov (United States)

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

    1990-01-01

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

  13. New facility for post irradiation examination of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo; Kawamura, Hiroshi [Oarai Research Establishment, Ibaraki-Ken (Japan)

    1995-09-01

    Beryllium is expected as a neutron multiplier and plasma facing materials in the fusion reactor, and the neutron irradiation data on properties of beryllium up to 800{degrees}C need for the engineering design. The acquisition of data on the tritium behavior, swelling, thermal and mechanical properties are first priority in ITER design. Facility for the post irradiation examination of neutron irradiated beryllium was constructed in the hot laboratory of Japan Materials Testing Reactor to get the engineering design data mentioned above. This facility consist of the four glove boxes, dry air supplier, tritium monitoring and removal system, storage box of neutron irradiated samples. Beryllium handling are restricted by the amount of tritium;7.4 GBq/day and {sup 60}Co;7.4 MBq/day.

  14. Irradiation embrittlement of neutron-irradiated ferritic steel

    Science.gov (United States)

    Kayano, H.; Narui, M.; Ohta, S.; Morozumi, S.

    1985-08-01

    In this study three kinds of Fe-Cr ferritic steels were examined by the instrumented Charpy test and tensile test before and after JMTR irradiation ( 2.2×10 23 f.n./m 2). In the unirradiated samples, 100%-martensite 5Cr-2Mo steel showed the highest adsorbed energy and the highest toughness at low temperatures, follewed by the 9Cr-2Mo steel, and the 20%-martensite 5Cr-2Mo steel showed the third highest toughness. In the irradiated samples, however, thoughness was low as a whole, especially in 20%-martensite 5Cr-2Mo steel. It was clarified that 100%-martensite 5Cr-2Mo steel had the lowest Ductile-to-Brittle Transition Temperature (DBTT) and the highest fracture toughness, and that its DBTT and fracture toughness changed a little upon irradiation, showing excellent irradiation characteristics. The general equations were considered for correlation among strength, ductillity, DBTT and fracture toughness ( J value)

  15. Rapid screening of the heterogeneity of DNA methylation by single-strand conformation polymorphism and CE-LIF in the presence of electro-osmotic flow.

    Science.gov (United States)

    Yu, Meng-Hsuan; Huang, Ya-Chi; Chang, Po-Ling

    2014-08-01

    DNA methylation is a complex event in epigenetic studies because of both the large CpG islands present upstream of the promoter region and the different distribution of DNA methylation despite similar methylation levels. For this reason, we proposed a fast, cost-effective method for the screening of DNA methylation based on SSCP and CE-LIF. In this study, the PCR products that were amplified from bisulfite-treated genomic DNA were denatured at 94°C, followed by immediate chilling in ice water to form the ssDNA. The ssDNA were separated by 1.5% poly(ethylene oxide) (Mavg 8 000 000 Da) in the presence of EOF according to the different conformations represented by their unique methylation states. This result demonstrated that four hepatocellular carcinoma cell lines represented a different heterogeneity of DNA methylation and could be distinguished by SSCP-CE. The results obtained from SSCP-CE also corresponded with those obtained from combined bisulfide restriction analysis and methylation-sensitive high-resolution melting analysis. Therefore, the proposed SSCP-CE method may potentially be used for rapid screening for determination of the heterogeneity of DNA methylation in further epigenetic studies and clinical diagnosis.

  16. The sensitive capillary electrophoretic-LIF method for simultaneous determination of curcuminoids in turmeric by enhancing fluorescence intensities of molecules upon inclusion into (2-hydroxypropyl)-β-cyclodextrin.

    Science.gov (United States)

    Kalaycıoğlu, Zeynep; Hashemi, Parya; Günaydın, Keriman; Erim, F Bedia

    2015-10-01

    Curcuminoids have received great attention in the past decades due to their health benefit properties. The aim of this study is to develop a very simple, rapid, and sensitive capillary zone electrophoresis technique coupled with a laser induced fluorescence detector (LIF) for the simultaneous determination of three major curcuminoids of turmeric, namely, curcumin, demethoxy curcumin (DMC), and bisdemethoxy curcumin (BDMC). Background electrolyte was selected as borate at pH 9.6 and (2-hydroxypropyl)-β-cyclodextrin (2-HP-β-CD) was added to prevent rapid alkali degradation of curcuminoids in buffer and to increase fluorescence intensities of molecules. With the addition of 2-HP-β-CD to the separation electrolyte, the fluorescence signal intensities of curcuminoids were enhanced considerably by 30, 40, and 54 fold for curcumin, DMC, and BDMC, respectively. The three curcuminoids of turmeric were fully separated and quantified in less than 4.5 min. The repeatability of the peak areas of curcuminoids for intra-day and inter-day experiments was in the satisfactory range of 2.26 and 2.55%, respectively. The LOD and LOQ values for the developed method were equal to or less than 0.081 and 0.270 μg/mL, respectively, for all curcuminoids. The developed method was successfully applied to find curcuminoids amount in turmeric samples and herbal supplements.

  17. LIF instrument for airborne measurements of OH, HO2 and RO2 radicals in the upper troposphere deployed on HALO during the OMO 2015 campaign

    Science.gov (United States)

    Künstler, Christopher; Broch, Sebastian; Bachner, Mathias; Bayer, Norbert; Dahlhoff, Knut; Fuchs, Hendrik; Holland, Frank; Hofzumahaus, Andreas; Jansen, Peter; Wolters, Jörg; Zöger, Martin; Wahner, Andreas

    2016-04-01

    We present the first deployment of our instrument for the measurement of OH, HO2 and RO2 radical concentrations in the upper troposphere aboard the German research aircraft HALO during the OMO (Oxidation Mechanism Observation) campaigns in winter and summer 2015. Radicals are detected by laser induced fluorescence (LIF) in two separate measurement cells. One for the direct detection of OH (OH channel) and one for alternating measurements of HO2 and RO2 radicals after chemical conversion to OH by the reaction with NO (ROx channel). A special air inlet for the OH channel was developed and built at Forschungszentrum Jülich, based on the shrouded-inlet design by Eisele et al. It allows a controlled reduction of the air flow velocity prior to sampling as well as the performance of inflight calibrations via photolysis of ambient water vapor. The inflight calibrations show that the OH detection sensitivity increases substantially - roughly by a factor of 5 - over the altitude range from ground to 10 km. This is supported by the theoretical pressure dependence which is in good accordance with the measured data. The ROx channel has no special inlet system and samples directly from the fast airflow along the aircraft. We will give an overview of the instrumental setup for the application on HALO and show first results from flights performed during the OMO-EU (winter 2015) and OMO-Asia campaign (summer 2015).

  18. LIF LiDAR high resolution ground truth data, suitable to validate medium-resolution bands of MODIS/Terra radiometer in case of inner waterbody ecological monitoring

    Science.gov (United States)

    Pelevin, Vadim; Zavialov, Peter; Zlinszky, Andras; Khimchenko, Elizaveta; Toth, Viktor; Kremenetskiy, Vyacheslav

    2017-04-01

    The report is based on field measurements on the lake Balaton (Hungary) in September 2008 as obtained by Light Induced Fluorescence (LIF) portable LiDAR UFL-8. It was tested in natural lake waters and validated by contact conventional measurements. We had opportunity to compare our results with the MODIS/Terra spectroradiometer satellite images received at the satellite monitoring station of the Eötvös Loránd University (Budapest, Hungary) to make an attempt of lidar calibration of satellite medium-resolution bands data. Water quality parameters were surveyed with the help of UFL-8 in a time interval very close to the satellite overpass. High resolution maps of the chlorophyll-a, chromophoric dissolved organic matter and total suspended sediments spatial distributions were obtained. Our results show that the resolution provided by laboratory measurements on a few water samples does not resemble actual conditions in the lake, and it would be more efficient to measure these parameters less accurately but in a better spatial distribution with the LiDAR. The UFL instrument has a great potential for being used for collecting ground truth data for satellite remote sensing of these parameters. Its measurement accuracy is comparable to classic water sample measurements, the measurement speed is high and large areas can be surveyed in a time interval very close to the satellite overpass.

  19. Effects of Nanosilver Exposure on Cholinesterase Activities, CD41, and CDF/LIF-Like Expression in ZebraFish (Danio rerio Larvae

    Directory of Open Access Journals (Sweden)

    Marzhan Myrzakhanova

    2013-01-01

    Full Text Available Metal nanosolicoparticles are suspected to cause diseases in a number of organisms, including man. In this paper, we report the effects of nanosilver (Ag, 1–20 nm particles on the early development of the zebrafish, a well-established vertebrate model. Embryos at the midgastrula stage were exposed to concentrations ranging from 100 to 0.001 mg/L to verify the effects on different endpoints: lethality, morphology, expression of cholinergic molecules, and development of the immune system. (1 Relative risk of mortality was exponential in the range between 0.001 and 10 mg/L. Exposure to 100 mg/L caused 100% death of embryos before reaching the tail-bud stage. (2 Developmental anomalies were present in the 72 h larvae obtained from embryos exposed to nanosilver: whole body length, decreased eye dimension, and slow response to solicitation by gentle touch with a needle tip, with a significant threshold at 0.1 mg/L. (3 Dose-dependent inhibition of acetylcholinesterase activity was significant among the exposures, except between 1 mg/L and 10 mg/L. (4 The distribution of CD41+ cells and of CDF/LIF-like immunoreactivity was altered according to the Ag concentration. The possible effect of nanosilver in impairing immune system differentiation through the inhibition of molecules related to the cholinergic system is discussed.

  20. Preliminary Study on LiF4-ThF4-PuF4 Utilization as Fuel Salt of miniFUJI Molten Salt Reactor

    Science.gov (United States)

    Waris, Abdul; Aji, Indarta K.; Pramuditya, Syeilendra; Widayani; Irwanto, Dwi

    2016-08-01

    miniFUJI reactor is molten salt reactor (MSR) which is one type of the Generation IV nuclear energy systems. The original miniFUJI reactor design uses LiF-BeF2-ThF4-233UF4 as a fuel salt. In the present study, the use of LiF4-ThF4-PuF4 as fuel salt instead of LiF-BeF2-ThF4-UF4 will be discussed. The neutronics cell calculation has been performed by using PIJ (collision probability method code) routine of SRAC 2006 code, with the nuclear data library is JENDL-4.0. The results reveal that the reactor can attain the criticality condition with the plutonium concentration in the fuel salt is equal to 9.16% or more. The conversion ratio diminishes with the enlarging of plutonium concentration in the fuel. The neutron spectrum of miniFUJI MSR with plutonium fuel becomes harder compared to that of the 233U fuel.

  1. (Irradiation creep of graphite)

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, C.R.

    1990-12-21

    The traveler attended the Conference, International Symposium on Carbon, to present an invited paper, Irradiation Creep of Graphite,'' and chair one of the technical sessions. There were many papers of particular interest to ORNL and HTGR technology presented by the Japanese since they do not have a particular technology embargo and are quite open in describing their work and results. In particular, a paper describing the failure of Minor's law to predict the fatigue life of graphite was presented. Although the conference had an international flavor, it was dominated by the Japanese. This was primarily a result of geography; however, the work presented by the Japanese illustrated an internal program that is very comprehensive. This conference, a result of this program, was better than all other carbon conferences attended by the traveler. This conference emphasizes the need for US participation in international conferences in order to stay abreast of the rapidly expanding HTGR and graphite technology throughout the world. The United States is no longer a leader in some emerging technologies. The traveler was surprised by the Japanese position in their HTGR development. Their reactor is licensed and the major problem in their graphite program is how to eliminate it with the least perturbation now that most of the work has been done.

  2. Irradiation of food - the facts

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, V. (International Food Research Association, Leatherhead (UK))

    1985-06-01

    The author outlines the history of the process for the interest of the baking industry, and discusses the difficulties concerning public relations in this field, before the introduction of irradiation to the British food industry.

  3. Sanitary safety of irradiated foods

    Science.gov (United States)

    Wolf, A.

    Consideration on the acceptability of the irradiation of food, especially from the toxicological point of view, is presented. The conditions of the potencial permission of the preservation of food by radiation in CSSR are briefly given.

  4. Progress in food irradiation: Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Stegeman, H.

    1982-11-01

    The Dutch contribution gives an accurate description of the gamma radio preservation facility where a great variety of types of fruit, vegetables, meat and spices were treated with radiosensitivity of bacteria and fungi as well as spores being tested. Wholesomeness studies were limited to feeding tests on pigs and mutagenity tests on Salmonella typhimurium. 12 products were given as authorized for irradiation stating irradiation effect, radiation dose and shelf-life duration.

  5. ATLAS Pixel Group - Photo Gallery from Irradiation

    CERN Multimedia

    2001-01-01

    Photos 1,2,3,4,5,6,7 - Photos taken before irradiation of Pixel Test Analog Chip and Pmbars (April 2000) Photos 8,9,10,11 - Irradiation of VDC chips (May 2000) Photos 12, 13 - Irradiation of Passive Components (June 2000) Photos 14,15, 16 - Irradiation of Marebo Chip (November 1999)

  6. Integrated Assessment of Pharmacological and Nutritional Cardiovascular Risk Management: Blood Pressure Control in the DIAbetes and LifEstyle Cohort Twente (DIALECT

    Directory of Open Access Journals (Sweden)

    Christina M. Gant

    2017-07-01

    Full Text Available Cardiovascular risk management is an integral part of treatment in Type 2 Diabetes Mellitus (T2DM, and requires pharmacological as well as nutritional management. We hypothesize that a systematic assessment of both pharmacological and nutritional management can identify targets for the improvement of treatment quality. Therefore, we analysed blood pressure (BP management in the DIAbetes and LifEstyle Cohort Twente (DIALECT. DIALECT is an observational cohort from routine diabetes care, performed at the ZGT Hospital (Almelo and Hengelo, The Netherlands. BP was measured for 15 minutes with one minute intervals. Sodium and potassium intake was derived from 24-hour urinary excretion. We determined the adherence to pharmacological and non-pharmacological guidelines in patients with BP on target (BP-OT and BP not on target (BP-NOT. In total, 450 patients were included from August 2009 until January 2016. The mean age was 63 ± 9 years, and the majority was male (58%. In total, 53% had BP-OT. In those with BP-NOT, pharmacological management was suboptimal (zero to two antihypertensive drugs in 62% of patients, and nutritional guideline adherence was suboptimal in 100% of patients (only 8% had a sodium intake on target, 66% had a potassium intake on target, 3% had a sodium-to-potassium ratio on target, and body mass index was <30 kg/m2 in 35%. These data show pharmacological undertreatment and a low adherence to nutritional guidelines. Uncontrolled BP is common in T2DM, and our data show a window of opportunity for improving BP control, especially in nutritional management. To improve treatment quality, we advocate to incorporate the integrated monitoring of nutritional management in quality improvement cycles in routine care.

  7. Effects of irradiation upon spices

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    ESR studies were performed on untreated and irradiated samples of paprika powder, ground black pepper, and a spice mixture of the following composition: paprika, 55%; black pepper, 14%; allspice, 9%; coriander, 9%; marjoram, 7%; cumin, 4%; and nutmeg, 2%. Gamma radiation doses from 0.5 to 5 Mrad were applied. In the case of paprika samples, the effect of moisture content on the formation and disappearance of radiation-induced free radicals was also investigated. Shortly after irradiation (on the day of radiation treatment) high amounts of free radicals were detected in irradiated spice samples but they diminished upon storage. After a period of 3 months the ESR signals of the irradiated samples approximated those of the controls. The free radicals found in unirradiated ground spices did not disappear during a storage period as long as one year. The formation and disappearance of radiation-induced free radicals were found to be strongly affected by the moisture content of samples. If a sample of low moisture content containing a high free radical concentration after irradiation was placed in an atmosphere of higher moisture content, the free radicals decayed rapidly.

  8. Irradiation damage to the lung

    Energy Technology Data Exchange (ETDEWEB)

    Fennessy, J.J.

    1987-07-01

    While some degree of injury to normal, non-tumor-bearing, intrathoracic structures always occurs following irradiation for cure or palliation of neoplastic disease, clinical expression of this injury is uncommon. However, under certain circumstances, clinical manifestations may be severe and life threatening. Acute radiographic manifestations of pulmonary injury usually appear either synchronous with or, more typically, seven to ten days after the onset of the clinical syndrome. The acute signs of edema and slight volume loss within the irradiated zone are nonspecific except for their temporal and spatial relationship to the irradiation of the patient. Resolution of the acute changes is followed by pulmonary cicatrization, which is almost always stable within one year after completion of therapy. Change in postirradiation scarring following stabilization of the reaction must always be assumed to be due to some other process. While the radiograph primarily reveals pulmonary injury, all tissues, including the heart and major vessels, are susceptible, and the radiologist must recognize that any change within the thorax of a patient who has undergone thoracic irradiation may be a complication of that treatment. Differentiation of irradiation injury from residual or recurrent tumor, drug reaction, or opportunistic infection may be difficult and at times impossible.

  9. Nutritional aspects of food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Murray, T.K.

    1981-08-01

    From the nutritional point of view the irradiation of fruits and vegetables presents few problems. It should be noted that irradiation-induced changes in the ..beta..-carotene content of papaya (not available to the Joint Expert Committee in 1976) have been demonstrated to be unimportant. The Joint Expert Committee also noted the need for more data on thiamine loss. These have been forthcoming and indicate that control of insects in rice is possible without serious loss of the vitamin. Experiments with other cereal crops were also positive in this regard. The most important evidence on the nutritional quality of irradiated beef and poultry was the demonstration that they contained no anti-thiamine properties. A point not to be overlooked is the rather serious loss of thiamine when mackerel is irradiated at doses exceeding 3 kGy. Recent evidence indicates that thiamine loss could be reduced by using a high dose rate application process. Though spices contribute little directly to the nutritional quality of the food supply they play an important indirect role. It is thus encouraging that they can be sterilized by irradiation without loss of aroma and taste and without significant loss of ..beta..-carotenes. Of future importance are the observations on single cell protein and protein-fat-carbohydrate mixtures. The reduction of net protein utilization in protein-fat mixtures may be the result of physical interaction of the components.

  10. Food irradiation: Gamma processing facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

    1997-12-31

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  11. Currently developing opportunities in food irradiation and modern irradiation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, R. [Director Business Development. SteriGenics International Inc. 17901 East Warren Avenue No. 4, Detroit, Michigan 48224-1333 (United States)

    1997-12-31

    I. Factor currently influencing advancing opportunities for food irradiation include: heightened incidence and awareness of food borne illnesses and causes. Concerns about ensuring food safety in international as well as domestic trade. Regulatory actions regarding commonly used fumigants/pesticides e.g. Me Br. II. Modern irradiator design: the SteriGenics {sup M}ini Cell{sup .} A new design for new opportunities. Faster installation of facility. Operationally and space efficient. Provides local {sup o}nsite control{sup .} Red meat: a currently developing opportunity. (Author)

  12. Post-irradiation examination and R and D programs using irradiated fuels at KAERI

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Yong Bum; Min, Duck Kee; Kim, Eun Ka and others

    2000-12-01

    This report describes the Post-Irradiation Examination(PIE) and R and D programs using irradiated fuels at KAERI. The objectives of post-irradiation examination (PIE) for the PWR irradiated fuels, CANDU fuels, HANARO fuels and test fuel materials are to verify the irradiation performance and their integrity as well as to construct a fuel performance data base. The comprehensive utilization program of the KAERI's post-irradiation examination related nuclear facilities such as Post-Irradiation Examination Facility (PIEF), Irradiated Materials Examination Facility (IMEF) and HANARO is described.

  13. Directional irradiances and fractional clouds

    Science.gov (United States)

    Pagh Nielsen, Kristian; Andersen, Elsa; Dragsted, Janne; Furbo, Simon

    2017-04-01

    For large scale implementation of solar energy, better understanding of the directional and temporal variations in the solar resource is needed. This includes understanding the shading within a multiple row field of solar panels and how this affects the electricity or heat production. We have studied directional irradiances measured simultaneously from 16 downward directions at 1 minute temporal resolution. Also, we have performed measurements of the variations in the field of view across individual solar heating panels in the operational solar district heating plant in Hedehusene in Denmark. By combining a model of directional diffuse irradiances with the field of view variation across a solar panel in a solar panel field we can quantify the effect of shading of diffuse irradiances on the heat flow from the panel.

  14. Neutron irradiation of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Ermi, R.M. [Pacific Northwest National Lab., Richland, WA (United States); Tsai, H. [Argonne National Lab., IL (United States)

    1998-03-01

    Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.

  15. Endodontics and the irradiated patient

    Energy Technology Data Exchange (ETDEWEB)

    Cox, F.L.

    1976-11-01

    With increasingly larger numbers of irradiated patients in our population, it seems likely that all dentists will eventually be called upon to manage the difficult problems that these patients present. Of utmost concern should be the patient's home care program and the avoidance of osteroradionecrosis. Endodontics and periodontics are the primary areas for preventing or eliminating the infection that threatens osteoradionecrosis. Endodontic treatment must be accomplished with the utmost care and maximum regard for the fragility of the periapical tissues. Pulpally involved teeth should never be left open in an irradiated patient, and extreme care must be taken with the between-visits seal. If one is called upon for preradiation evaluation, routine removal of all molar as well as other compromised teeth should be considered. Attention should be directed to the literature for further advances in the management of irradiated patients.

  16. Thermal Expansion of Irradiated Polytetrafluoroethylene

    OpenAIRE

    Subrahmanyam, HN; Subramanyam, SV

    1987-01-01

    The thermal expansion coefficient of gamma-irradiated Polytetrafluoroethylene (PTFE) has been measured in the temperature range 80-340 K by using a three-terminal capacitance technique. The samples are irradiated in air at room temperature with gamma rays from a $Co^{60}$ source at a dose rate of 0.26 Mrad/h. The change in crystallinity is measured by an x-ray technique. The expansion coefficient is found to increase with radiation dose below 140 K owing to the predominant effect of degradati...

  17. Dislocation morphology in deformed and irradiated niobium. [Neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C. P.

    1977-06-01

    Niobium foils of moderate purity were examined for the morphology of dislocations or defect clusters in the deformed or neutron-irradiated state by transmission electron microscopy. New evidence has been found for the dissociation of screw dislocations into partials on the (211) slip plane according to the Crussard mechanism: (a/2) (111) ..-->.. (a/3) (111) + (a/6) (111).

  18. Expression and the role of LIF and CD105 in placenta of patients with preeclampsia%子痫前期患者胎盘组织中LIF和CD105的表达及意义

    Institute of Scientific and Technical Information of China (English)

    王健; 胡洁; 王璟; 赵向寨; 秦珊; 卫艳芬

    2013-01-01

    目的 探讨子痫前期患者胎盘组织中白血病抑制因子(LIF)和CD105的表达及其意义.方法 采用免疫组织化学的方法,对20例正常孕妇(对照组)和45例子痫前期患者(其中轻度子痫前期患者25例,重度子痫前期患者20例)的胎盘组织中LIF和CD105表达水平进行检测,并分析两者的相关性.结果 与对照组比较,子痫前期组胎盘组织中LIF的表达明显降低(P0.05).子痫前期组CD105表达较对照组明显升高(P<0.01);重度子痫前期组较轻度子痫前期组明显升高(P<0.01).对照组及子痫前期组胎盘组织中的LIF与CD105的表达均呈负相关(P 0. 05 ). The expression of CD105 in preeclampsia placenta was significantly higher than that in controls ( P <0. 01 ),and was significantly higher in severe preeclampsia placenta than that in mild group( P < 0. 01 ). Negatively correlation between the LIF and CD105 was found both in study groups and control group( P <0.01 ). Conclusion The low expression of LIF and high expression of CD105 in preeclampsia with negative correction indicate that they may induce the occurrence and development of preeclampsia.

  19. Effects of LiF on microwave dielectric properties of 0.25Ca0.8Sr0.2TiO3–0.75Li0.5Nd0.5TiO3 ceramics

    Indian Academy of Sciences (India)

    Fei Liu; Changlai Yuan; Xinyu Liu; Jing Jing Qu

    2015-09-01

    The effects of LiF addition on sinterability, microstructure and microwave dielectric properties of 0.25Ca0.8Sr0.2TiO3–0.75Li0.5Nd0.5TiO3 ceramics were investigated. The LiF addition enhanced the sintering temperature of 0.25Ca0.8Sr0.2TiO3–0.75Li0.5Nd0.5TiO3 ceramics from 1200 to 1300°C, because the LiF addition could compensate the evaporation of Li during the sintering process. It was found that the bulk density and dielectric constant (r) gradually decreased, the quality factor (f) greatly increased and the temperature coefficient of resonant frequency (f) shifted to a near-zero value with the increase in LiF addition. Obviously, excess Li addition could efficiently improve the microwave dielectric properties. In addition, 0.25Ca0.8Sr0.2 TiO3–0.75Li0.5Nd0.5TiO3 + 4.0 wt% LiF ceramics sintered at 1350°C for 4 h exhibited good microwave dielectric properties of r ∼ 123.4, f ∼ 2209 GHz (at 2.43 GHz) and f ∼ 12.3 ppm °C–1.

  20. Inhomogeneous microstructural growth by irradiation

    DEFF Research Database (Denmark)

    Krishan, K.; Singh, Bachu Narain; Leffers, Torben

    1985-01-01

    In the present paper we discuss the development of heterogeneous microstructure for uniform irradiation conditions. It is shown that microstructural inhomogeneities on a scale of 0.1 μm can develop purely from kinematic considerations because of the basic structure of the rate equations used to d...

  1. Microstructural processes in irradiated materials

    Science.gov (United States)

    Byun, Thak Sang; Morgan, Dane; Jiao, Zhijie; Almer, Jonathan; Brown, Donald

    2016-04-01

    These proceedings contain the papers presented at two symposia, the Microstructural Processes in Irradiated Materials (MPIM) and Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation, held in the TMS 2015, 144th Annual Meeting & Exhibition at Walt Disney World, Orlando, Florida, USA on March 15-19, 2015.

  2. Preservation of foodstuffs by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sielaff, H.; Thiemig, F.; Schleusener, H. (Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Nahrungsgueterwirtschaft und Lebensmitteltechnologie)

    1985-03-01

    Application and experimental testing of irradiation in foodstuff processing are accomplished in more than 20 countries. Radiation treatment of foodstuffs and commodities with doses between 0.5 - 50 kGy is licensed in the GDR, too. Examples of application of ionizing radiation in food processing are discussed.

  3. Decommissioning of an irradiation unit

    Energy Technology Data Exchange (ETDEWEB)

    Richards, A.G. [Radiation Protection and Safety Services, Univ. of Leeds, Leeds (United Kingdom)

    2000-05-01

    Distributed throughout hospital, research establishments in the United Kingdom and many other countries are Irradiation Units and Teletherapy machines used for either research purposes or treatment of patients for radiotherapy. These Irradiation Units and Teletherapy machines are loaded with radioactive sources of either Cobalt 60 or Caesium 137. The activity of these sources can range from 1 Terabecquerel up to 100 Terabecquerels or more. Where it is possible to load the radioactive sources without removal from the shielded container into a transport package which is suitable for transport decommissioning of a Teletherapy machine is not a major exercise. When the radioactive sources need to be unloaded from the Irradiation Unit or Teletherapy machine the potential exists for very high levels of radiation. The operation outlined in the paper involved the transfer from an Irradiation Unit to a transport package of two 3.25 Terabecquerel sources of Cobalt 60. The operation of the removal and transfer comes within the scope of the United Kingdom Ionising Radiation Regulations 1985 which were made following the Recommendations of the International Commission on Radiological Protection. This paper illustrates a safe method for this operation and how doses received can be kept within ALARA. (author)

  4. Statistical criteria for characterizing irradiance time series.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Ellis, Abraham; Hansen, Clifford W.

    2010-10-01

    We propose and examine several statistical criteria for characterizing time series of solar irradiance. Time series of irradiance are used in analyses that seek to quantify the performance of photovoltaic (PV) power systems over time. Time series of irradiance are either measured or are simulated using models. Simulations of irradiance are often calibrated to or generated from statistics for observed irradiance and simulations are validated by comparing the simulation output to the observed irradiance. Criteria used in this comparison should derive from the context of the analyses in which the simulated irradiance is to be used. We examine three statistics that characterize time series and their use as criteria for comparing time series. We demonstrate these statistics using observed irradiance data recorded in August 2007 in Las Vegas, Nevada, and in June 2009 in Albuquerque, New Mexico.

  5. Ultrasonic Transducer Irradiation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Palmer, Joe [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Keller, Paul [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Kohse, Gordon [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Tittmann, Bernhard [Pennsylvania State Univ., University Park, PA (United States); Reinhardt, Brian [Pennsylvania State Univ., University Park, PA (United States); Rempe, Joy [Rempe and Associates, Idaho Falls, ID (United States)

    2015-02-01

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric

  6. How irradiation can help food processors

    Energy Technology Data Exchange (ETDEWEB)

    Upton, M. (University Coll., Dublin (Ireland). Dept. of Industrial Microbiology)

    1984-06-01

    A review is given of Cobalt-60 irradiation in the food processing industry, and in particular the techniques of preservation of foodstuffs and the extension of shelf life. A typical food irradiation facility is described, and the economics of such facilities are presented. The consumer acceptance and safety of irradiated foods are discussed, and the potential applications of a food irradiation programme in Ireland is examined.

  7. Neutron irradiation effects on plasma facing materials

    Science.gov (United States)

    Barabash, V.; Federici, G.; Rödig, M.; Snead, L. L.; Wu, C. H.

    2000-12-01

    This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.

  8. iTRAQ-based proteomic analysis of LI-F type peptides produced by Paenibacillus polymyxa JSa-9 mode of action against Bacillus cereus.

    Science.gov (United States)

    Han, Jinzhi; Gao, Peng; Zhao, Shengming; Bie, Xiaomei; Lu, Zhaoxin; Zhang, Chong; Lv, Fengxia

    2017-01-06

    LI-F type peptides (AMP-jsa9) produced by Paenibacillus polymyxa JSa-9 are a group of cyclic lipodepsipeptide antibiotics that exhibit a broad antimicrobial spectrum against Gram-positive bacteria and filamentous fungi, especially Bacillus cereus and Fusarium moniliforme. In this study, to better understand the antibacterial mechanism of AMP-jsa9 against B. cereus, the ultrastructure of AMP-jsa9-treated B. cereus cells was observed by both atomic force microscopy and transmission electron microscopy, and quantitative proteomic analysis was performed on proteins extracted from treated and untreated bacterial cells by using isobaric tag for relative and absolute quantitation (iTRAQ) labeling and LC-MS/MS analysis to access differentially expressed proteins. Furthermore, multiple experiments were conducted to validate the results of the proteomic analysis, including determinations of ATP, NAD((+))H, NADP((+))H, reactive oxygen species (ROS), the activities of catalase (CAT) and superoxide dismutase (SOD), and the relative expression of target genes by quantitative real-time PCR. Bacterial cells exposed to AMP-jsa9 showed irregular surfaces with bleb projections and concaves; we hypothesize that AMP-jsa9 penetrated the cell wall and was anchored on the cytoplasmic membrane and that ROS accumulated in the cell membrane after treatment with AMP-jsa9, modulating the bacterial membrane properties and increasing membrane permeability. Consequently, the blebs were formed on the cell wall by the impulsive force of the leakage of intercellular contents. iTRAQ-based proteomic analysis detected a total of 1317 proteins, including 176 differentially expressed proteins (75 upregulated (fold >2) and 101 downregulated (fold <0.5)). Based on proteome analysis, the putative pathways of AMP-jsa9 action against B. cereus can be summarized as: (i) inhibition of bacterial sporulation, thiamine biosynthesis, energy metabolism, DNA transcription and translation, and cell wall biosynthesis

  9. Lif Takviyeli Plastik Levhalar ile Güçlendirilmiş Betonarme Kirişlerde Arayüz Gerilmelerini Etkileyen Parametreler

    Directory of Open Access Journals (Sweden)

    Barış Sayın

    2010-01-01

    Full Text Available Betonarme kirişlerin, dıştan FRP (Lif Takviyeli Plastik levhalarla güçlendirilmesi, güçlendirmede etkin bir yöntem olarak kabul edilmektedir. Yöntem, FRP malzemesinin, yüksek dayanım-ağırlık oranı, iyi korozyon direnci, farklı kesit şekilleri ve köşelere uygulanabilirlik avantajlarından dolayı kullanılır olmuştur. Konuyla ilgili birçok çalışma 1990'lı yılların başlarından itibaren yürütülmüştür. Gerçekleştirilecek olan çalışma kapsamında, FRP ile güçlendirilen betonarme kirişlerin arayüz gerilmelerini etkileyen parametreler deneysel ve nümerik olarak incelenecektir. FRP'nin kirişe uygulanmasında kullanılan yapıştırıcı kalınlığı, yapıştırıcı türü ve beton yüzeyinin durumu, üretilen deney numuneleri üzerinde eğilme etkisine maruz bırakılarak mukayeseli olarak incelenecektir. Sonrasında, ANSYS® WB sonlu elemanlar programı kullanılarak FRP'li betonarme kirişler modellenecek ve analizler gerçekleştirilecektir. Yapıştırıcı kalınlığı, yapıştırıcı türü, beton yüzeyi parametreleri girilerek yapılacak analizler neticesinde gerilme değerleri elde edilecektir. Böylece, analitik ifadelerde yer alan kayma gerilmesi ve normal gerilme bağıntılarının modifiye edilmesi gerekliliği ortaya konulacaktır. Sonlu eleman analizleri ile deneysel sonuçlar karşılaştırılacak, uyumluluğu irdelenip, sonuçlar ve önerilerin sunulması suretiyle çalışma tamamlanacaktır.

  10. Evaluation of irradiation hardening of proton irradiated stainless steels by nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Yabuuchi, Kiyohiro, E-mail: kiyohiro.yabuuchi@qse.tohoku.ac.jp [Graduate School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aza-Aoba, Aobaku, Sendai, Miyagi 980-8579 (Japan); Kuribayashi, Yutaka [Graduate School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aza-Aoba, Aobaku, Sendai, Miyagi 980-8579 (Japan); Nogami, Shuhei, E-mail: shuhei.nogami@qse.tohoku.ac.jp [Graduate School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aza-Aoba, Aobaku, Sendai, Miyagi 980-8579 (Japan); Kasada, Ryuta, E-mail: r-kasada@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hasegawa, Akira, E-mail: akira.hasegawa@qse.tohoku.ac.jp [Graduate School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aza-Aoba, Aobaku, Sendai, Miyagi 980-8579 (Japan)

    2014-03-15

    Ion irradiation experiments are useful for investigating irradiation damage. However, estimating the irradiation hardening of ion-irradiated materials is challenging because of the shallow damage induced region. Therefore, the purpose of this study is to prove usefulness of nanoindentation technique for estimation of irradiation hardening for ion-irradiated materials. SUS316L austenitic stainless steel was used and it was irradiated by 1 MeV H{sup +} ions to a nominal displacement damage of 0.1, 0.3, 1, and 8 dpa at 573 K. The irradiation hardness of the irradiated specimens were measured and analyzed by Nix–Gao model. The indentation size effect was observed in both unirradiated and irradiated specimens. The hardness of the irradiated specimens changed significantly at certain indentation depths. The depth at which the hardness varied indicated that the region deformed by the indenter had reached the boundary between the irradiated and unirradiated regions. The hardness of the irradiated region was proportional to the inverse of the indentation depth in the Nix–Gao plot. The bulk hardness of the irradiated region, H{sub 0}, estimated by the Nix–Gao plot and Vickers hardness were found to be related to each other, and the relationship could be described by the equation, HV = 0.76H{sub 0}. Thus, the nanoindentation technique demonstrated in this study is valuable for measuring irradiation hardening in ion-irradiated materials.

  11. Schedule and status of irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rowcliffe, A.F.; Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    To provide an updated summary of the status of irradiation experiments for the neutron-interactive materials program. The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has two irradiation experiments in reactor; and 8 experiments in the planning or design stages. Postirradiation examination and testing is in progress on 18 experiments.

  12. Food irradiation: research and technology, preface

    Science.gov (United States)

    Many interesting and exciting developments have occurred in the field of food irradiation since the publication of the first edition of Food Irradiation: Research and Technology in 2006. The 2nd edition of the book reviews our latest knowledge on food irradiation, highlights the current developments...

  13. Production of thermoluminescent dosemeters based on MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm; Producao de dosimetros termoluminescentes a base de MgB{sub 4}O{sub 7}: Dy e MgB{sub 4}O{sub 7}: Tm

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiza Freire de; Souza, Divanizia N., E-mail: luizaf25@hotmail.com, E-mail: divanizi@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Programa de Pos-Graduacao em Fisica

    2013-07-01

    The thermoluminescent dosimetry (TL) is a well-established technique for the detection of ionizing radiation in hospitals, clinics, and industrial establishments where there is the need to quantify the radiation. For this practice is require the use phosphors which are sensitive to radiation. Some phosphors are already commonly used in this practice, for example, TLD-100 (LiF: Mg, Ti), CaSO{sub 4}:Tm and CaSO{sub 4}:Dy. A compound that was most recently introduced in dosimetry and has many advantageous features to detect neutrons, electrons and gamma is the magnesium tetraborate (MgB{sub 4}O{sub 7}), but the undoped material is not good for dosimetry, since signal does not show satisfactory thermoluminescence. The present work presents the analysis of the compound MgB{sub 4}O{sub 7} when doped with rare earth elements, thulium (Tm) and dysprosium (Dy). The production of MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm occurred under acidic conditions. Following the process of crystal growth, several tests were made on phosphors produced to verify the quality of materials as TL dosimeter. Initially, was made the identification of the crystalline phases found in the material, using the technique of X-ray diffractometry, and then were evaluated and compared the TL emission curves of the crystals with two different types of dopants, to this, the samples were irradiated with different radiation sources: {sup 137}Cs (0,66 MeV), {sup 60}Co (1.25 MeV) and X-rays (0.41 MeV) and based on the results was evaluated the energy dependence of phosphors. Another characteristic analyzed, was the decay of TL signal for the material (fading). The results show that the material can be an excellent TL dosimeter when doped with rare earth elements Dy and Tm. (author)

  14. Study of effective dose of various protocols in equipment cone beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Soares, M. R.; Maia, A. F. [Universidade Federale de Sergipe, Departamento de Fisica, Cidade Universitaria Prof. Jose Aloisio de Campos, Marechal Rondon s/n, Jardim Rosa Elze, 49-100000 Sao Cristovao, Sergipe (Brazil); Batista, W. O. [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Barbalho, Salvador, 40301015 Bahia (Brazil); Caldas, L. V. E.; Lara, P. A., E-mail: mrs2206@gmail.com [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    Currently the cone beam computed tomography is widely used in various procedures of dental radiology. Although the doses values associated with the procedures of cone beam CT are low compared to typical values associated with dental radiology procedure in multi slices CT. However can be high compared to typical values of other techniques commonly used in dental radiology. The present scenario is a very wide range of designs of equipment and, consequently, lack of uniformity in all parameters associated with x-ray generation and geometry. In this context, this study aimed to evaluate and calculate the absorbed dose in organs and tissues relevant and estimate effective dose for different protocols with different geometries of exposure in five cone beam CT equipment. For this, a female Alderson anthropomorphic phantom, manufactured by Radiology Support Devices was used. The phantom was irradiated with 26 dosimeters LiF: Mg, Ti (TLD-100), inserted in organs and tissues along the layers forming the head and neck of the phantom. The equipment used, in this present assessment, was: i-CAT Classical, Kodak 9000 3D, Gendex GXCB 500, Sirona Orthophos X G 3D and Planmeca Pro Max 3D. The effective doses were be determined by the ICRP 103 weighting factors. The values were between 7.0 and 111.5 micro Sv, confirming the broad dose range expected due to the diversity of equipment and protocols used in each equipment. The values of effective dose per Fov size were: between 7 and 51.2 micro Sv for located Fov; between 17.6 and 52.0 micro Sv for medium Fov; and between 11.5 and 43.1 micro Sv to large Fov (maxillofacial). In obtaining the effective dose the measurements highlighted a relevance contribution of dose absorbed by the remaining organs (36%), Salivary glands (30%), thyroid (12%) and bone marrow (12%). (Author)

  15. Investigation of the thermoluminescent properties of nanosized Alpha-Al{sub 2} O{sub 3} doped with carbon for application in digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edna C., E-mail: edca@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Ferraz, Wilmar B.; Faria, Luiz O., E-mail: ferrazw@cdtn.br, E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Thermoluminescent (TL) materials are mainly used in personal and environmental dosimetry. In addition to these applications, their use as the sensor element in the manufacturing of digital radiographic films has been investigated. Particularly, there is an interest concerned to the influence of the particle size in the TL response and in the resolution of the digital imaging. Aluminum oxide, or alumina, is a mineral found in the ruby or sapphire form, and may be synthetically produced in the alpha or gamma crystalline phase. Since the 50s, these materials have been studied in their diverse forms and phases. Particularly, the microsized α-Al{sub 2}O{sub 3}:C is considered one of the best TL dosimeter ever produced in the word. In this work, nanosized alumina particulates in the alpha phase, sintered at different temperatures and doped with different concentrations of carbon, were investigated aiming application in industrial radiography and medical diagnosis. The mixture of the oxide powder with the carbon source was pressed and sintered at temperatures of 1740 deg C and 1745 deg C, under reducing atmosphere. For doping purposes we have used two sources of carbon, graphite and high purity polyvinyl acetate (PVA), respectively. During the sintering process, intentional inclusion of oxygen vacancies into the oxide crystal lattice is performed, allowing the inclusion of carbon atoms into the crystal lattice. Among the samples studied, the nanosized alumina doped with 0.01at.% of carbon and sintered at 1745 deg C has shown an excellent thermoluminescent response, with sensitivity higher than that of LiF: Mg, Ti (TLD-100), when irradiated under similar conditions. This is an excellent result, since the material with nanosized particles offers the best features for radiographic image. Thus, it is concluded that the α-Al{sub 2}O{sub 3} doped with 0.01at.% of carbon is a good candidate for use in TL films for application in digital radiography. (author)

  16. Development of data base on food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi; Kume, Tamikazu; Hashimoto, Shoji [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Izumi, Fumio

    1995-12-01

    For the exact understanding on food irradiation in Japan, it is important to provide information of food irradiation to consumers, industries and government offices. However, many of information on food irradiation are only restricted in a few experts or institutes relating to this field. For this reason, data base of food irradiation has been completed together with the systems necessary for input the data using computer. In this data base, about 630 data with full reports were inputted in computer in the field of wholesomeness studies, irradiation effects on food, radiation engineering, detection methods of irradiated food and Q and A of food irradiation for easy understanding. Many of these data are inputted by Japanese language. Some English reports on wholesomeness studies are also included which were mainly obtained from international projects of food irradiation. Many of data on food irradiation are responsible in the fields of food science, dietetics, microbiology, radiation biology, molecular biology, medical science, agricultural science, radiation chemistry, radiation engineering and so on. Data base of food irradiation contains many useful data which can apply to many other fields of radiation processing not only on food irradiation but also on sterilization of medical equipments, upgrading of agricultural wastes and others. (author).

  17. Spectrophotometric analysis of irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Josimovic, L.; Cudina, I.

    1987-01-01

    Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

  18. Study of rice. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lien, J.J.; Chau, R.S.; Chen, S.C.; Chu, S.L.; Fu, Y.K.; Fang, C.K.; Fu, Y.H.

    1981-03-01

    The purpose of this experiment was to investigate whether the /sup 60/Co gamma-irradiated milled rice packed in economic and practical sealed bags could be preserved in common granaries in Taiwan for more than one year rather than slightly over one month without quality deterioration. As a result of this experiment we found that during the preservation of over a period of 18 months, the contents, such as moisture, ash, protein and fiber, of Tainan-5 Bon-Lai (Japonica Type) rice irradiated with 20 and 40 krad doses were quite stable, whereas reducing sugar showed slight fluctuations but did not vary significantly either. The fat, vitamin B/sub 1/ and niacin contents were found being reduced, while the increase in fatty acid content was an inevitable phenomenon along with the proceeding of the preservation.

  19. Food irradiation development in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Khan, I. (Nuclear Inst. for Food and Agriculture, Peshawar (Pakistan))

    1990-01-01

    Large scale trials were held to extend the storage life of potatoes, onions and dry fruits by gamma radiation. It was concluded that radiation preservation of potatoes and onions was much cheaper as compared to conventional methods. A dose of 1 kGy can control the insects in dry fruits and nuts. The consumers' acceptability and market testing performed during the last four years are also conducive to the commercialization of the technology in this country. The Government of Pakistan has accorded clearance for the irradiation of some food items like potatoes, onions, garlic and spices for human consumption. The Pakistan Radiation Services (PARAS), the commercial irradiator (200 Kci) at Lahore, has already started functioning in April 1987. It is planned to start large scale sterilization of spices by gamma radiation in PARAS shortly. (author).

  20. Food irradiation development in Pakistan

    Science.gov (United States)

    Khan, I.

    The large scale trials were held to extend the storage life of potatoes, onions and dry fruits by gamma radiation. It was concluded that radiation preservation of potatoes and onions was much cheaper as compared to conventional methods. A dose of 1 kGy can control the insects in dry fruits and nuts. The consumers' acceptability and market testing performed during the last four years are also conducive to the commercialization of the technology in this country. The Government of Pakistan has accorded clearance for the irradiation of some food items like potatoes, onions, garlic and spices for human consumption. The Pakistan Radiation Services (PARAS), the commercial irradiator (200 Kci) at Lahore, has already started functioning in April, 1987. It is planned to start large scale sterilization of spices by gamma radiation in PARAS shortly.

  1. Particular applications of food irradiation fresh produce

    Science.gov (United States)

    Prakash, Anuradha

    2016-12-01

    On fresh fruits and vegetables, irradiation at low and medium dose levels can effectively reduce microbial counts which can enhance safety, inhibit sprouting to extend shelf-life, and eliminate or sterilize insect pests which can serve to facilitate trade between countries. At the dose levels used for these purposes, the impact on quality is negligible. Despite the fact that regulations in many countries allow the use of irradiation for fresh produce, the technology remains under-utilized, even in the light of an increase in produce related disease outbreaks and the economic benefits of extended shelf life and reduced food waste. Putative concerns about consumer acceptance particularly for produce that is labeled as irradiated have deterred many companies from using irradiation and retailers to carry irradiated produce. This section highlights the commercial use of irradiation for fresh produce, other than phytosanitary irradiation which is covered in supplementary sections.

  2. Irradiation effects on hydrases for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu E-mail: mfuruta@riast.osakafu-u.ac.jp; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio

    2000-03-01

    To apply an irradiation technique to sterilize 'Hybrid' biomedical materials including enzymes, we selected papain, a well-characterized plant endopeptidase as a model to examine durability of enzyme activity under the practical irradiation condition in which limited data were available for irradiation inactivation of enzymes. Dry powder and frozen aqueous solution of papain showed significant durability against {sup 60}Co-gamma irradiation suggesting that, the commercial irradiation sterilizing method is applicable without modification. Although irradiation of unfrozen aqueous papain solution showed an unusual change of the enzymatic activity with the increasing doses, and was totally inactivated at 15 kGy, we managed to keep the residual activity more than 50% of initial activity after 30-kGy irradiation, taking such optimum conditions as increasing enzyme concentration from 10 to 100 mg/ml and purging with N{sub 2} gas to suppress the formation of free radicals. (author)

  3. Stereotactic Irradiation of Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To investigate the best stereotactic irradiation (STI) technique in treatment of small lung tumors, using dose-volume statistics. Methods: Dose-volume histogram (DVH) of the study phantom consisting of CT using the software of FOCUS-3D planning system. The beam was a 6MV X-ray from a Varian 2300C. The analysis data of Dose-volume statistics was from the technique used for: (1) 2- 12 arcs; (2) 20° - 45° separation angle of arcs; (3) 80° - 160° of gantry rotation. Then we studied the difference of DVH with various irradiation techniques and the influence of target positions and field size by calculated to the distribution of dose from 20%- 90% of the six targets in the lung with 3×3 cm2, 4′ 4 cm2 and 5′ 5 cm2 field size. Results: The volume irradiated pulmonary tissue was the smallest using a six non-coplanar 120° arcs with 30° separation between arcs in the hypothetical set up, the non-coplanar SRI was superiority than conventional one's. The six targets were chosen in the right lung, the volume was the largest in geometric center and was decreased in hilus, bottom, anterior chest wall, lateral wall and apex of the lung in such an order. The DVH had significant change with an increasing field size. Conclusion: the irradiation damage of normal pulmonary tissue was the lowest using the six non-coplanar 120° arcs with a 30° separation between arcs by <5×5 cm2 field and the position of target was not a restricting factor.

  4. RERTR-8 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-8, was designed to test monolithic mini-fuel plates fabricated via hot isostatic pressing (HIP), the effect of molybdenum (Mo) content on the monolithic fuel behavior, and the efficiency of ternary additions to dispersion fuel particles on the interaction layer behavior at higher burnup. The following report summarizes the life of the RERTR-8 experiment through end of irradiation, including as-run neutronic analysis, thermal analysis and hydraulic testing results.

  5. RERTR-6 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-6 was designed to evaluate several modified fuel designs that were proposed to address the possibility of breakaway swelling due to porosity within the (U. Mo) Al interaction product observed in the full-size plate tests performed in Russia and France1. The following report summarizes the life of the RERTR-6 experiment through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.

  6. Irradiation history of meteoritic inclusions

    DEFF Research Database (Denmark)

    Wielandt, Daniel Kim Peel

    somewhat philosophical question. . . did our solar system form under special circumstances, and what are the implications for the occurrence of similar planetary systems and ultimately life around other stars? In this thesis, we present methods and measurements pertaining to the study of irradiation......K anomalies were formed during co-storage in the protoplanetary disc, providing constraints on the disc dynamics leading up to planet formation....

  7. Microstructural processes in irradiated materials

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Thak Sang; Morgan, Dane; Jiao, Zhijie; Almer, Jonathan; Brown, Donald

    2016-04-01

    This is an editorial article (preface) for the publication of symposium papers in the Journal of Nuclear materials: These proceedings contain the papers presented at two symposia, the Microstructural Processes in Irradiated Materials (MPIM) and Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation, held in the TMS 2015, 144th Annual Meeting & Exhibition at Walt Disney World, Orlando, Florida, USA on March 15–19, 2015.

  8. Food Preservation by Irradiation (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Urrows, Grace M.

    1968-01-01

    Up to 30% of food harvests are lost in some parts of the world because of animal pests and microorganisms. Nuclear techniques can help reduce and extend the shelf life of these foods. Around 55 countries now have food irradiation programs. The use of radiation is the most recent step in man's attempts to preserve some of his harvest for the lean part of the year.

  9. Spectroscopic analysis of irradiated erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Selim, Nabila S. [Biophysics Lab, Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), AEA, P.O. Box 29, Madinat Nasr, Cairo (Egypt); Desouky, Omar S., E-mail: omardesouky@yahoo.com [Biophysics Lab, Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), AEA, P.O. Box 29, Madinat Nasr, Cairo (Egypt); Ismail, Nagla M.; Dakrory, Amira Z. [Physics Department, Faculty of Girls for Arts, Sciences and Education, Ain Shams University, Cairo (Egypt)

    2011-12-15

    The aim of the present work is to study the effect of gamma radiation on the lipid part of the erythrocyte membrane, and to test the efficiency of lipoic acid as a radioprotector. This effect was evaluated using electron paramagnetic resonance (EPR), and Fourier transform infrared (FT-IR) spectroscopy. The results showed an increase in the number of spin density by 14%, 22% and 65% after exposure to 25, 50 and 100 Gy respectively; whereas there was a decline in the obtained density after incubation with lipoic acid by a factor of approximately 32%. The FT-IR spectra of the irradiated erythrocytes samples showed a marked decrease in the intensity of all characteristic peaks, which increased as the irradiation dose increased. The second-derivative of these spectra, allow the conformationally sensitive membrane acyl chain methylene stretching modes to be separated from the protein (mostly hemoglobin) vibrations that dominate the spectra of intact cells. The 2850 cm{sup -1} band showed changes in the band shape and position after exposure to 50 and 100 Gy. Therefore it can be concluded that the band at 2850 cm{sup -1} only is useful in monitoring the radiation effect of the lipids cell membrane intact cells. - Highlights: > Effect of {gamma} radiation on erythrocyte membrane was studied using EPR and FT-IR. > Efficiency of {alpha}-lipoic acid as radioprotector was tested. > Lipoic acid diminished the free radicals number after gamma irradiation by 32%. > FT-IR spectra of the irradiated erythrocyte showed a decrease in their intensity. > Lipoic acid enhances the membrane to resist the action of gamma radiation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD)

    2016-09-29

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fuel Cycle Research and Development (FCRD)

    2016-09-29

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  13. High-temperature long-lasting stability assessment of a single-crystal diamond detector under high-flux neutron irradiation

    Science.gov (United States)

    Pilotti, R.; Angelone, M.; Marinelli, M.; Milani, E.; Verona-Rinati, G.; Verona, C.; Prestopino, G.; Montereali, R. M.; Vincenti, M. A.; Schooneveld, E. M.; Scherillo, A.; Pietropaolo, A.

    2016-11-01

    An innovative diamond detector layout is presented that is designed to operate at high temperature under intense neutron and gamma fluxes. It is made of a 500 μm “electronic grade” diamond film with 100 nm thick Ag metal contacts deposited onto each surface of the film by means of thermal evaporation. A 2 μ \\text{m} thick layer of 6LiF has been deposited on top of one of the two Ag contacts to make the detector sensitive to thermal neutrons. The device was tested at the ISIS spallation neutron source (Rutherford Appleton Laboratory, UK) using the INES beam line. The detector was continuously irradiated for 100 hours in vacuum (p = 10-5 \\text{mbar}) , exposed to a neutron flux of about 106 n cm-2 s-1 at a temperature T =150 ^\\circ \\text{C} . The aim of this experiment was to study the time dependence of the diamond detector performance while operating at high temperature under irradiation, providing a first experimental proof of reliable continuous operation for 100 hours at high temperature in a harsh environment.

  14. Effect of irradiation on the streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Ki Dong; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Kyung Hee Univ., Seoul (Korea, Republic of)

    2007-03-15

    To observe direct effect of irradiation on cariogenic Streptococcus mutans. S. mutans GS5 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Viability and changes in antibiotic sensitivity, morphology, transcription of virulence factors, and protein profile of bacterium after irradiation were examined by pour plate, disc diffusion method, Transmission electron microscopy. RT-PCR, and SDS-PAGE, respectively. After irradiation with 10 and 20 Gy, viability of S. mutans was reduced. Further increase in irradiation dose, however, did not affect the viability of the remaining cells of S. mutans. Irradiated S. mutans was found to have become sensitive to antibiotics. In particular, the bacterium irradiated with 40 Gy increased its susceptibility to cefotaxime, penicillin, and tetracycline. Under the transmission electron microscope, number of morphologically abnormal cells was increased as the irradiation dose was increased. S. mutans irradiated with 10 Gy revealed a change in the cell wall and cell membrane. As irradiation dose was increased. a higher number of cells showed thickened cell wall and cell membrane and lysis, and appearance of ghost cells was noticeable. In RT-PCR, no difference was detected in expression of gtfB and spaP between cells with and without irradiation of 40 Gy. In SDS-PAGE, proteins with higher molecular masses were gradually diminished as irradiation dose was increased. These results suggest that irradiation affects the cell integrity of S. mutans, as observed by SDS-PAGE, and as manifested by the change in cell morphology, antibiotic sensitivity, and eventually viability of the bacterium.

  15. Development of detection methods for irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Seung; Kim, Chong Ki; Lee, Hae Jung [Korea Atomic Energy Research Insitiute, Taejon (Korea, Republic of); Kim, Kyong Su [Chosun University, Kwangju (Korea, Republic of)

    1999-04-01

    To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats. The analysis of DNA damage made on single cells by agarose gel electrophoresis (DNA 'comet assay') can be used to detect irradiated food. All the samples irradiated with over 0.3 kGy were identified to detect post-irradiation by the tail length of their comets. Irradiated samples showed comets with long tails, and the tail length of the comets increased with the dose, while unirradiated samples showed no or very short tails. As a result of the above experiment, the DNA 'comet assay' might be applied to the detection of irradiated grains as a simple, low-cost and rapid screening test. When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from leic acid. 1,7 hexadecadiene was the highest amount in irradiated beef, pork and chicken. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1,7-hexadecadiene and 8-heptadecen were detected as major compounds. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks.

  16. Development of detection methods for irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Seung; Kim, Chong Ki; Lee, Hae Jung [Korea Atomic Energy Research Insitiute, Taejon (Korea, Republic of); Kim, Kyong Su [Chosun University, Kwangju (Korea, Republic of)

    1999-04-01

    To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats. The analysis of DNA damage made on single cells by agarose gel electrophoresis (DNA 'comet assay') can be used to detect irradiated food. All the samples irradiated with over 0.3 kGy were identified to detect post-irradiation by the tail length of their comets. Irradiated samples showed comets with long tails, and the tail length of the comets increased with the dose, while unirradiated samples showed no or very short tails. As a result of the above experiment, the DNA 'comet assay' might be applied to the detection of irradiated grains as a simple, low-cost and rapid screening test. When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from leic acid. 1,7 hexadecadiene was the highest amount in irradiated beef, pork and chicken. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1,7-hexadecadiene and 8-heptadecen were detected as major compounds. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks.

  17. Irradiation preservation of seafood: Literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.

    1987-10-01

    The application of gamma-irradiation for extending the shelf life of seafood has been of interest for many years. This report reviews a number of studies on seafood irradiation conducted over the past several years. Topics covered include seafood irradiation techniques and dosages, species applicability and differences, the effects of packaging on seafood preservation, and changes in organoleptic acceptability as a result of irradiation. Particular attention is given to radiation effects (likely and unlikely) of concern to the public. These include the potential for generation of toxic chemical products, botulinum toxin production, and other health concerns. No scientifically defensible evidence of any kind was found for any harmful effect of irradiation of seafoods at the doses being considered (less than 300 krad), and all indications are that irradiation is an acceptable and needed additional tool for seafood preservation. 49 refs., 14 figs., 14 tabs.

  18. Thermal analysis applied to irradiated propolis

    Science.gov (United States)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; del Mastro, Nélida Lucia

    2002-03-01

    Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were 60Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600°C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

  19. Thermal analysis applied to irradiated propolis

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; Mastro, N.L. del E-mail: nelida@usp.br

    2002-03-01

    Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were {sup 60}Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600 deg. C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

  20. Renal graft irradiation in acute rejection

    Energy Technology Data Exchange (ETDEWEB)

    Pilepich, M.V.; Sicard, G.A.; Breaux, S.R.; Etheredge, E.E.; Blum, J.; Anderson, C.B.

    1983-03-01

    To evaluate the effect of graft irradiation in the treatment of acute rejection of renal transplants, a randomized study was conducted from 1978 to 1981. Patients with acute rejection were given standard medical management in the form of intravenous methylprednisolone, and were chosen randomly to receive either graft irradiation (175 rads every other day, to a total of 525 rads) or simulated (sham) irradiation. Eighty-three rejections occurring in 64 grafts were randomized to the protocol. Rejection reversal was recorded in 84.5% of control grafts and 75% of the irradiated grafts. Recurrent rejections were more frequent and graft survival was significantly lower in the irradiated group (22%) than in the control group (54%). Graft irradiation does not appear to be beneficial in the treatment of acute rejection of renal transplants when used in conjunction with high-dose steroids.

  1. (Irradiation embrittlement of reactor pressure vessels)

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, W.R.

    1990-09-24

    The traveler served as a member of the two-man US Nuclear Regulatory Commission sponsored team who visited the Prometey Complex in Leningrad to assess the potential for expanded cooperative research concerning integrity of the primary pressure boundary in commercial light-water reactors. The emphasis was on irradiation embrittlement, structural analysis, and fracture mechanics research for reactor pressure vessels. At the irradiation seminar in Cologne, presentations were made by German, French, Finnish, Russian, and US delegations concerning many aspects of irradiation of pressure vessel steels. The traveler made presentations on mechanisms of irradiation embrittlement and on important aspects of the Heavy-Section Steel Irradiation Program results of irradiated fracture mechanics tests.

  2. The IRMA gamma irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Berger, L.; Raboin, M.; Corbiere, J. [IRSN, Fontenat-aux-roses (France)

    2011-07-01

    The IRMA cobalt-60 irradiation cell has been installed at the Saclay research centre (25 km from Paris) for 40 years. IRMA is a facility with a maximum authorized capacity of 1, 700 TBq (i.e. approx. 46, 000 Ci). It is a test facility intended primarily for research and development studies on how equipment and materials respond to dose or dose rate exposure. Cobalt-60 gamma photons are the reference in this field. Irradiation is panoramic and achieved using 4, independent, cylindrical sealed sources (11 mm in diameter and 452 mm in length). When not in use, the sources are stored in a lead cask with 0.30 m thick walls to allow safe access inside the cell (uncontaminated environment). With an internal volume of 24 m{sup 3}, it can accommodate a very wide variety of geometric configurations for exposure to gamma radiation. Available dose rates range from 5 {mu}Gy/h (which is the background radiation in the cell when the sources are enclosed in their lead cask) to 25 kGy/h (value obtained 10 cm from a source holder containing all four sources). The resulting doses can be used in experiments representing relatively extreme situations (reactor accidents, dose after x years for equipment in hot cells, reprocessing plants, and so on).The IRMA facility has performed several irradiation tests on new components for EPR and LWR. The IRMA facility is also adapted to check the performance of new biological shieldings and protections for reactors and reprocessing plants. In several other fields of nuclear applications, this facility is useful to characterize and calibrate radiation detectors for the nuclear, space, and military industries

  3. Irradiation Testing of Ultrasonic Transducers

    Energy Technology Data Exchange (ETDEWEB)

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2014-07-30

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  4. Mandibulotomy in the irradiated patient

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.; Freeman, J.; Birt, D.

    1989-04-01

    Though the mandibular swing, as an approach to certain upper aerodigestive tract malignancies, has been gaining popularity in recent years, there has been little reported as to the feasibility of this procedure in subjects who have received radical preoperative radiotherapy. We have recently reported the results of 23 such patients, and we now present an update. The results presented are of a retrospective analysis of 44 patients, 50% of whom received radical preoperative radiotherapy to fields including the osteotomy site. As in the previous study, there were no statistically significant differences between the complication rates in the irradiated and nonirradiated patient populations. All the patients were orally rehabilitated.

  5. Thymus irradiation for myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Currier, R.D.; Routh, A.; Hickman, B.T.; Douglas, M.A.

    1983-01-01

    Twenty-eight patients with progressive myasthenia gravis without thymoma received treatment of 3000 rads (30 Gy) to the anterior mediastinum, and a followup was conducted for five to 18 years. Twenty-four patients had generalized myasthenia, and four had ocular myasthenia gravis. Twenty patients with generalized myasthenia survived the several month post-treatment period and improved, but four died during that period. The improvement lasted a median of 1.5 years, and older patients had longer remissions than younger patients. The four patients who had ocular myasthenia did not change after treatment. Mediastinal irradiation produces a temporary remission in generalized myasthenia.

  6. AFIP-6 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Danielle M Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-09-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-6 was designed to evaluate the performance of monolithic uranium-molybdenum (U-Mo) fuels at a length prototypic to that of the ATR fuel plates (45 inches in length). The AFIP-6 test was the first test with plates in a swaged condition with longer fuel zones of approximately 22.5 inches in length1,2. The following report summarizes the life of the AFIP-6 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  7. Effect of LiF Coating on the Thermal Oxidation Characteristics for Boron Powder%LiF包覆对硼粉热氧化特性的影响

    Institute of Scientific and Technical Information of China (English)

    陈涛; 张先瑞; 王园园; 黄凌; 肖金武

    2013-01-01

    In order to investigate the effect of LiF coating on the thermal oxidation characteristics for amorphous boron powder,the thermal analysis experiment of boron coated with LiF (BLiF) was conducted by DSC-TC. Propellant samples containing BLif were prepared. The heat of detonation and heat of combustion were determined by an oxygen bomb calorimeter. The effects of BLif on the energy release features in primary combustion and after-burning processes of the propellant were discussed. The results indicate that in comparison with amorphous boron, BLiF shows a fast oxidation reaction at 599 XL ,and a 39. 9% higher percentage of boron participated in B/O reaction. The propellant containing BLiF makes primary combustion and after-burning energy release efficiencies (ηc1 and ηc2) increased and combustion efficiencies of B enhanced significantly from 65.48% to 81 .57%. This is due to the consumption of B2O3 layer on the boron particle surface via endothermic reaction of LiF and B2O3 at high temperature and the acceleration of B/O reaction.%为考察LiF包覆对硼粉热氧化特性的影响,采用DSC-TG技术对LiF包覆硼(BLiF)进行热分析试验.制备了含BLiF的推进剂样品.采用氧弹量热计测试其爆热和热值.考察了BLiF对推进剂一次、二次燃烧过程中能量释放特性的影响.结果表明:与无定形硼相比,BLiF在599℃存在快速氧化反应,有39.9%(质量百分数)的B参与了B/O反应.含BLiF的推进剂使一次能量释放效率和二次能量释放效率明显提高,硼的燃烧效率从65.48%提高到81.57%.这是由高温下LiF通过吸热反应消耗硼粉表面B2O3氧化层,加速B/O反应所引起的.

  8. 6LiF Semiconductor Sandwich Spectrometer for Fast Neutron Spectrum Measurement%用于快中子能谱测量的6LiF夹心半导体谱仪

    Institute of Scientific and Technical Information of China (English)

    蒋勇; 李俊杰; 张涛; 范晓强; 郑春

    2012-01-01

    A detector of 6LiF semiconductor sandwich spectrometer was designed and manufactured. Characteristics of the spectrometer were tested in the fast neutron critical assembly. Measurement principle, configuration of detector and electronic circuit were introduced. Fast neutron spectrum was measured using the 6LiF semiconductor sandwich spectrometer. When the detector's 6 LiF mass thickness is 186 μg/cm2, the spectrometer's energy resolution is 363 keV in the thermal neutron field. For this spectrometer, the optimal fathomable neutron energy range is 0. 3-7. 5 MeV, and the background counts only take possession of 1 % in this area.%本文介绍了6 LiF夹心谱仪的测量原理、自行设计研制的6LiF夹心半导体谱仪探头结构及电子学系统组成等.在热中子场中测试了夹心谱仪的性能,获得了α粒子峰、T粒子峰及“和”峰在多道上的位置与能量分辨率,并用T粒子与“和”峰两个能量点的峰位对谱仪系统进行了能量刻度.分别用效应探头和本底探头测量了临界装置表面的效应谱和本底谱,当效应探头采用的6 LiF镀层质量厚度为186 μg/cm2时,6 LiF夹心谱仪对热中子的能量分辨率为363 keY,测量中子最佳能区为0.3~7.5 MeV,在该能区内,本底谱约占1%.

  9. Food irradiation: an unused weapon against hunger

    Energy Technology Data Exchange (ETDEWEB)

    Libby, W.F. (Univ. of California, Los Angeles); Black, E.F.

    1978-02-01

    The author urges use of food irradiation technology now to ease the world's food supply shortage. The holdup appears to relate to whether irradiation is an additive under the 1958 Food Additive Amendment to the Federal Food, Drug and Cosmetic Act, although the FAO-IAEA-World Health Organization in 1976 declared five foods unconditionally safe for human consumption after irradiation. Another delay is seen as lack of commercial feasibility data. (PCS)

  10. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  11. Squamous cell carcinoma in situ after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi [Yokohama City Univ. (Japan). School of Medicine; Sugiyama, Asami

    1997-12-31

    We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

  12. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Lan, K.N. [Post-harvest Technology Institute, 4, Ngo Quyen-Ha Noi (Viet Nam); Lam, N.D. [Ha Noi Radiation Center, VAEC, 5T-160, Nghiado, Tuliem, Ha Noi (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Preliminary test of mango (Mangifera indica) preservation by irradiated chitosan coating has been investigated. The coating by using irradiated chitosan in 1.5% solution has extended the shelf life of mango from 7 to 15 days. At the 15th day mango coated by irradiated chitosan has been keeping good color, natural ripening, without spoilage, weight loss 10%, whereas the mango without coating was spoiled completely and the coating of fruit with unirradiated chitosan inhibited the ripening. (author)

  13. Radiation damage and recovery of medium heavy and light inorganic crystalline, glass and glass ceramics materials after irradiation with 150 MeV protons and 1.2 MeV gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, K.T.; Dormenev, V.; Novotny, R.W.; Zaunick, H.G. [II. Physikalisches Institut, JLU Giessen (Germany); Borisevich, A.; Korjik, M.; Kozlov, D. [INP BSU, Minsk (Belarus); Kalinov, V.; Voitovich, A. [Institute of Physics of National Academy of Science, Minsk (Belarus); Kavatsyuk, M. [KVI-CART, University Groningen (Netherlands)

    2015-07-01

    Further concepts of the detectors at HEP experiments will require using cheap, capable for a mass production and radiation hard materials, especially for application at collider experiments. A set of samples with volume 1-2 cm{sup 3} of the middle light and light materials: crystalline BaF{sub 2}, Y{sub 3}A{sub l5}O{sub 12}:Ce, Y{sub 3}A{sub l5}O{sub 12}:Pr, Lu{sub 3}A{sub l5}O{sub 12}:Ce, LiF and newly developed glass and glass ceramics DSB:Ce and DSL:Ce were irradiated with gamma-quanta with absorbed dose 100 Gy and 150 MeV protons up to fluence 5 x 10{sup 13} p/cm{sup 2}. Here we report results of the comparison of the optical transmission damage and recovery after different types of irradiation. A significant acceleration of the induced absorption recovery is observed at the DSB:Ce samples illuminated with visible and IR light. This effect is similar to one observed by us in PWO. It indicates that radiation induced absorption in DSB: Ce scintillation material can be retained at the acceptable level by stimulation with light at the conditions of a strong irradiation environment of the collider experiments.

  14. The studies of irradiation hardening of stainless steel reactor internals under proton and xenon irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chaoliang; Zhang, Lu; Qian, Wangjie; Mei, Jinna; Liu, Xiang Bing [Suzhou Nuclear Power Research Institute, Suzuhou (China)

    2016-06-15

    Specimens of stainless steel reactor internals were irradiated with 240 keV protons and 6 MeV Xe ions at room temperature. Nanoindentation constant stiffness measurement tests were carried out to study the hardness variations. An irradiation hardening effect was observed in proton- and Xe-irradiated specimens and more irradiation damage causes a larger hardness increment. The Nix-Gao model was used to extract the bulk-equivalent hardness of irradiation-damaged region and critical indentation depth. A different hardening level under H and Xe irradiation was obtained and the discrepancies of displacement damage rate and ion species may be the probable reasons. It was observed that the hardness of Xe-irradiated specimens saturate at about 2 displacement/atom (dpa), whereas in the case of proton irradiation, the saturation hardness may be more than 7 dpa. This discrepancy may be due to the different damage distributions.

  15. Tolerance of edible flowers to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H., E-mail: ackoike@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2011-07-01

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  16. The irradiation effects on zirconium alloys

    Science.gov (United States)

    Negut, Gh.; Ancuta, M.; Radu, V.; Ionescu, S.; Stefan, V.; Uta, O.; Prisecaru, I.; Danila, N.

    2007-05-01

    Pressure tube samples were irradiated under helium atmosphere in the TRIGA Steady State Research and Material Test Reactor of the Romanian Institute for Nuclear Research (INR). These samples are made of the Zr-2.5%Nb alloy used as structural material for the CANDU Romanian power reactors. After irradiation, mechanical tests were performed in the Post Irradiation Examination Laboratory (PIEL) to study the influence of irradiation on zirconium alloys mechanical behaviour. The tensile test results were used for structural integrity assessment. Results of the tests are presented. The paper presents, also, pressure tube structural integrity assessment.

  17. Food irradiation facilities: Requirements and technical aspects

    Science.gov (United States)

    Mittendorfer, Josef

    2016-12-01

    This survey presents some aspects and requirement for food irradiation facilities. Topics like radiation source, dose ranges and dose rate are discussed, together with logistics and operational considerations

  18. Study of irradiation creep of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, H.; Strain, R.V.; Smith, D.L. [Argonne National Lab., IL (United States)] [and others

    1997-08-01

    Thin-wall tubing was produced from the 832665 (500 kg) heat of V-4 wt.% Cr-4 wt.% Ti to study its irradiation creep behavior. The specimens, in the form of pressurized capsules, were irradiated in Advanced Test Reactor and High Flux Isotope Reactor experiments (ATR-A1 and HFIR RB-12J, respectively). The ATR-A1 irradiation has been completed and specimens from it will soon be available for postirradiation examination. The RB-12J irradiation is not yet complete.

  19. Detection of hydrocarbons in irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Maitani, Tamio [National Inst. of Health Sciences, Tokyo (Japan); Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Kobayashi, Yasuo; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Establishment

    2003-06-01

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  20. Fermentation of irradiated sugarcane must

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Andre Ricardo; Horii, Jorge [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Agroindustria, Alimentos e Nutricao]. E-mail: aralcard@esalq.usp.br; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia

    2003-12-01

    Bacillus and Lactobacillus are bacteria that usually contaminate the ethanolic fermentation by yeasts and my influence yeast viability. As microorganisms can be killed by ionizing radiation, the efficacy of gamma radiation in reducing the population of certain contaminating bacteria from sugarcane must was examined and, as a consequence, the beneficial effect of lethal doses of radiation on some parameters of yeast-based ethanolic fermentation was verified. Must from sugarcane juice was inoculated with bacteria of the general Bacillus and Lactobacillus. The contaminated must was irradiated with 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. After ethanolic fermentation by the yeast (Saccharomyces cerevisiae) the total and volatile acidity produced during the process were evaluated: yeast viability and ethanol yield were also recorded. Treatments of gamma radiation reduced the population of the contaminating bacteria in the sugarcane must. The acidity produced during the fermentation decreased as the dose rate of radiation increased. Conversely, the yeast viability increased as the dose rate of radiation increased. Gamma irradiation was an efficient treatment to decontaminate the must and improved its parameters related to ethanolic fermentation, including ethanol yield, which increased 1.9%. (author)

  1. Uranium briquettes for irradiation target

    Energy Technology Data Exchange (ETDEWEB)

    Saliba-Silva, Adonis Marcelo; Garcia, Rafael Henrique Lazzari; Martins, Ilson Carlos; Carvalho, Elita Fontenele Urano de; Durazzo, Michelangelo, E-mail: saliba@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Direct irradiation on targets inside nuclear research or multiple purpose reactors is a common route to produce {sup 99}Mo-{sup 99m}Tc radioisotopes. Nevertheless, since the imposed limits to use LEU uranium to prevent nuclear armament production, the amount of uranium loaded in target meats has physically increased and new processes have been proposed for production. Routes using metallic uranium thin film and UAl{sub x} dispersion have been used for this purpose. Both routes have their own issues, either by bringing difficulties to disassemble the aluminum case inside hot cells or by generating great amount of alkaline radioactive liquid rejects. A potential route might be the dispersion of powders of LEU metallic uranium and nickel, which are pressed as a blend inside a die and followed by pulse electroplating of nickel. The electroplating provides more strength to the briquettes and creates a barrier for gas evolution during neutronic disintegration of {sup 235}U. A target briquette platted with nickel encapsulated in an aluminum case to be irradiated may be an alternative possibility to replace other proposed targets. This work uses pulse Ni-electroplating over iron powder briquette to simulate the covering of uranium by nickel. The following parameters were applied 10 times for each sample: 900Hz, -0.84A/square centimeters with duty cycle of 0.1 in Watts Bath. It also presented the optical microscopy analysis of plated microstructure section. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  3. Infectivity of irradiated and non-irradiated metacestodes of Taenia saginata

    Energy Technology Data Exchange (ETDEWEB)

    Geerts, S.; Borchgrave, J. de; Brandt, J.R.A.; Kumar, V.; Deken, R. de; Falla, N.; Brabant, R. van (Institute of Tropical Medicine, Antwerp (Belgium). Veterinary Dept.)

    No data are available on the fate of irradiated cysticerci of T. saginata in the human intestine. Since there is no definitive host of T. saginata other than man, this experiment was set up to study the infectivity of irradiated cysticerci of T. saginata in human volunteers in order to determine the minimal effective irradiation dose to inhibit their development. (Author).

  4. Effects of ion beam irradiation on semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Nashiyama, Isamu; Hirao, Toshio; Itoh, Hisayoshi; Ohshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Energetic heavy-ion irradiation apparatus has been developed for single-event effects (SEE) testing. We have applied three irradiation methods such as a scattered-ion irradiation method, a recoiled-atom irradiation method, and a direct-beam irradiation method to perform SEE testing efficiently. (author)

  5. Application of thermal-dissociation laser induced fluorescence (TD-LIF to measurement of HNO3, Σalkyl nitrates, Σperoxy nitrates, and NO2 fluxes using eddy covariance

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2006-01-01

    Full Text Available Nitrogen exchange between the atmosphere and biosphere directly influences atmospheric composition. While much is known about mechanisms of NO and N2O emissions, instrumentation for the study of mechanisms contributing to exchange of other major nitrogen species is quite limited. Here we describe the application of a new technique, thermal dissociation-laser induced fluorescence (TD-LIF, to eddy covariance measurements of the fluxes of NO2, total peroxy acyl and peroxy nitrates, total alkyl and multifunctional alkyl nitrates, and nitric acid. The technique offers the potential for investigating mechanisms of exchange of these species at the canopy scale over timescales from days to years. Examples of flux measurements at a ponderosa pine plantation in the mid-elevation Sierra Nevada Mountains in California are reported and used to evaluate instrument performance.

  6. Spectral characteristics of radiation emitted by a YAG:Nd/sup 3 +/ laser with a saturable absorber in the form of an LiF crystal containing F/sub 2//sup -/ centers

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, Y.L.; Kirpichnikov, A.V.; Lisitsyn, V.N.; Marennikov, S.I.

    1981-05-01

    An experimental investigation was made of the spectral characteristics of radiation emitted by a YAG:Nd/sup 3 +/ laser in which an LiF crystal containing F/sub 2//sup -/ centers was used as a passive switch. Single-frequency emission and mode locking operation regimes were investigated. In the single-frequency regime the minimum width of the emission line was 5 x 10/sup -3/ cm/sup -1/ for a single pulse. The frequency selection mechanism involved spatially inhomogeneous saturation of the absorption. Mode locking took place in a ring resonator when a saturable crystal filter with an initial transmission 0.7 was used. The use of a switch containing color centers made it possible to generate picosecond pulses simply and reliably.

  7. A peptide derived from the CD loop-D helix region of ciliary neurotrophic factor (CNTF) induces neuronal differentiation and survival by binding to the leukemia inhibitory factor (LIF) receptor and common cytokine receptor chain gp130

    DEFF Research Database (Denmark)

    Rathje, Mette; Pankratova, Stanislava; Nielsen, Janne;

    2011-01-01

    been suggested to be important for the cytokine interaction with LIFR. We designed a peptide, termed cintrofin, that encompasses this region. Surface plasmon resonance analysis demonstrated that cintrofin bound to LIFR and gp130, but not to CNTFRa, with apparent K(D) values of 35nM and 1.1n......M, respectively. Cintrofin promoted the survival of cerebellar granule neurons (CGNs), in which cell death was induced either by potassium withdrawal or H(2)O(2) treatment. Cintrofin induced neurite outgrowth from CGNs, and this effect was inhibited by specific antibodies against both gp130 and LIFR, indicating...... and LIF had no neuritogenic effect but were able to inhibit cintrofin-induced neuronal differentiation, indicating that cintrofin and cytokines compete for the same receptors. In addition, cintrofin induced the phosphorylation of STAT3, Akt, and ERK, indicating that it exerts cell signaling properties...

  8. Effect of LIF-withdrawal on acetylcholine synthesis in the embryonic stem cell line CGR8 is not mediated by STAT3, PI3Ks or cAMP/PKA pathways.

    Science.gov (United States)

    Michel-Schmidt, Rosmarie; Kirkpatrick, Charles James; Wessler, Ignaz

    2015-11-01

    Acetylcholine (ACh) acts as a local cellular signaling molecule and is widely expressed in nature, including mammalian cells and embryonic stem cells. The murine embryonic stem cell line CGR8 synthesizes and releases substantial amounts of ACh. Particularly during early differentiation - a period associated with multiple alterations in geno-/phenotype functions - synthesis and release of ACh are increased by 10-fold. In murine stem cells second messengers of the STAT-3, PI3K and cAMP/PKA pathways are involved in maintaining self-renewal and pluripotency. The present experiments were designed to test whether blockers of these signaling pathways enhance ACh cell content in the presence of LIF, i.e. when CGR8 is pluripotent. NSC74859, an inhibitor of STAT-3, affected neither the proliferation rate nor ACh cell content, whereas the more sensitive STAT-3 inhibitor FLLL31 reduced the proliferation rate and increased ACh cell content by about 3-fold. The PI3K inhibitor LY294002 reduced the proliferation rate but did not modify the ACh cell content, whereas the PKA inhibitor H89 produced effects comparable to FLLL31. Interestingly, in control experiments a strong inverse correlation was found between cell density and ACh cell content, which could explain the 3-fold increase in the ACh cell content observed in the presence of FLLL31 and H89. Forskolin, a PKA activator, had no effect. In conclusion, it appears unlikely that the 10-fold increase in ACh cell content induced by LIF removal, i.e. during early differentiation, is mediated by second messengers of the STAT-3, PI3K and cAMP/PKA pathways. However, the PI3K pathway appears to be involved in control of the inverse relation between cell density and ACh cell content, because this correlation was significantly attenuated in the presence of LY294002.

  9. Reprocessing technology development for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H.; Sakamoto, N. [Oarai Research Establishment, Ibaraki-ken (Japan); Tatenuma, K. [KAKEN Co., Ibaraki-ken (Japan)] [and others

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for neutron multiplier and plasma facing material in a fusion reactor. Therefore, it is necessary to develop the beryllium reprocessing technology for effective resource use. And, we have proposed reprocessing technology development on irradiated beryllium used in a fusion reactor. The preliminary reprocessing tests were performed using un-irradiated and irradiated beryllium. At first, we performed beryllium separation tests using un-irradiated beryllium specimens. Un-irradiated beryllium with beryllium oxide which is a main impurity and some other impurities were heat-treated under chlorine gas flow diluted with Ar gas. As the results high purity beryllium chloride was obtained in high yield. And it appeared that beryllium oxide and some other impurities were removed as the unreactive matter, and the other chloride impurities were separated by the difference of sublimation temperature on beryllium chloride. Next, we performed some kinds of beryllium purification tests from beryllium chloride. And, metallic beryllium could be recovered from beryllium chloride by the reduction with dry process. In addition, as the results of separation and purification tests using irradiated beryllium specimens, it appeared that separation efficiency of Co-60 from beryllium was above 96%. It is considered that about 4% Co-60 was carried from irradiated beryllium specimen in the form of cobalt chloride. And removal efficiency of tritium from irradiated beryllium was above 95%.

  10. Brazilian Consumer views on food irradiation

    NARCIS (Netherlands)

    Behrens, J.H.; Barcellos, M.N.; Frewer, L.J.; Nunes, T.P.; Landgraf, M.

    2009-01-01

    This study investigated the consumer attitude to food irradiation in São Paulo, Brazil, through a qualitative research perspective. Three focus groups were conducted with 30 consumers, responsible for food choices and purchases. Both irradiated and nonirradiated food samples were served in the

  11. Embrittlement behavior of neutron irradiated RAFM steels

    Energy Technology Data Exchange (ETDEWEB)

    Gaganidze, E. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung II, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)]. E-mail: ermile.gaganidze@imf.fzk.de; Schneider, H.-C. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung II, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Dafferner, B. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung II, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Aktaa, J. [Forschungszentrum Karlsruhe, Institut fuer Materialforschung II, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2007-08-01

    The effects of neutron irradiation on the embrittlement behavior of reduced activation ferritic/martensitic (RAFM) steel EUROFER97 for different heat treatment conditions have been investigated. The irradiation to 16.3 dpa at different irradiation temperatures (250-450 {sup o}C) was carried out in the Petten High Flux Reactor in the framework of the HFR Phase-IIb (SPICE) irradiation project. Several reference RAFM steels (F82H-mod, OPTIFER-Ia, GA3X) and MANET-I were also irradiated at selected temperatures. The embrittlement behavior and hardening were investigated by instrumented Charpy-V tests with subsize specimens. The neutron irradiation induced embrittlement and hardening of as-delivered EUROFER97 are comparable to those of investigated reference steels, being mostly pronounced for 250 {sup o}C and 300 {sup o}C irradiation temperatures. Heat treatment of EUROFER97 at higher austenization temperature substantially improves the embrittlement behavior at irradiation temperatures of 250 {sup o}C and 350 {sup o}C.

  12. RBE of Cells Irradiated by Carbon Ions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The cells were mouse melanoma B16,human cervical squamous carcinoma HeLa,Chinese hamster pulmonary V79,and human hepatoma SMMC-7721.For~(12)C ion experiment,the cells of 1.55×10~5/ml were seeded in 35mm diameter petri dish and allowed to grow one day befbre irradiation.When immediately irradiated,the medium

  13. Food irradiation; Global aspects and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, Akira (Tokyo Univ. of Agriculture (Japan). Nodai Research Institute)

    1990-07-01

    This paper reviews researches, commentaries, and conference and public records of food irradiation, published mainly during the period 1987-1989, focusing on the current conditions of food irradiation that may pose not only scientific or technologic problems but also political issues or consumerism. Approximately 50 kinds of food, although not enough to fill economic benefit, are now permitted for food irradiation in the world. Consumerism is pointed out as the major factor that precludes the feasibility of food irradiation in the world. In the United States, irradiation is feasible only for spices. Food irradiation has already been feasible in France, Hollands, Belgium, and the Soviet Union; has under consideration in the Great Britain, and has been rejected in the West Germany. Although the feasibility of food irradiation is projected to increase gradually in the future, commercial success or failure depends on the final selection of consumers. In this respect, the role of education and public information are stressed. Meat radicidation and recent progress in the method for detecting irradiated food are referred to. (N.K.) 128 refs.

  14. 10 CFR 36.33 - Irradiator pools.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Irradiator pools. 36.33 Section 36.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and Performance... indicator must be provided in a clearly visible location to indicate if the pool water level is below the...

  15. Schedule and status of irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P. [Oak Ridge National Lab., TN (United States)

    1998-03-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has four irradiation experiments in reactor, and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  16. In situ ion irradiation of zirconium carbide

    Science.gov (United States)

    Ulmer, Christopher J.; Motta, Arthur T.; Kirk, Mark A.

    2015-11-01

    Zirconium carbide (ZrC) is a candidate material for use in one of the layers of TRISO coated fuel particles to be used in the Generation IV high-temperature, gas-cooled reactor, and thus it is necessary to study the effects of radiation damage on its structure. The microstructural evolution of ZrCx under irradiation was studied in situ using the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory. Samples of nominal stoichiometries ZrC0.8 and ZrC0.9 were irradiated in situ using 1 MeV Kr2+ ions at various irradiation temperatures (T = 20 K-1073 K). In situ experiments made it possible to continuously follow the evolution of the microstructure during irradiation using diffraction contrast imaging. Images and diffraction patterns were systematically recorded at selected dose points. After a threshold dose during irradiations conducted at room temperature and below, black-dot defects were observed which accumulated until saturation. Once created, the defect clusters did not move or get destroyed during irradiation so that at the final dose the low temperature microstructure consisted only of a saturation density of small defect clusters. No long-range migration of the visible defects or dynamic defect creation and elimination were observed during irradiation, but some coarsening of the microstructure with the formation of dislocation loops was observed at higher temperatures. The irradiated microstructure was found to be only weakly dependent on the stoichiometry.

  17. Electron irradiation of dry food products

    Science.gov (United States)

    Grünewald, Th.

    The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10∗∗4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50°C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the iradiation field in a closed conveyor system.

  18. Passive SiC irradiation temperature monitor

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, G.E.

    1996-04-01

    A new, improved passive irradiation temperature monitoring method was examined after an irradiation test at 627{degrees}C. The method is based on the analysis of thermal diffusivity changes during postirradiation annealing of polycrystalline SiC. Based on results from this test, several advantages for using this new method rather than a method based on length or lattice parameter changes are given.

  19. Embrittlement behavior of neutron irradiated RAFM steels

    Science.gov (United States)

    Gaganidze, E.; Schneider, H.-C.; Dafferner, B.; Aktaa, J.

    2007-08-01

    The effects of neutron irradiation on the embrittlement behavior of reduced activation ferritic/martensitic (RAFM) steel EUROFER97 for different heat treatment conditions have been investigated. The irradiation to 16.3 dpa at different irradiation temperatures (250-450 °C) was carried out in the Petten High Flux Reactor in the framework of the HFR Phase-IIb (SPICE) irradiation project. Several reference RAFM steels (F82H-mod, OPTIFER-Ia, GA3X) and MANET-I were also irradiated at selected temperatures. The embrittlement behavior and hardening were investigated by instrumented Charpy-V tests with subsize specimens. The neutron irradiation induced embrittlement and hardening of as-delivered EUROFER97 are comparable to those of investigated reference steels, being mostly pronounced for 250 °C and 300 °C irradiation temperatures. Heat treatment of EUROFER97 at higher austenization temperature substantially improves the embrittlement behavior at irradiation temperatures of 250 °C and 350 °C.

  20. Mechanical response of proton beam irradiated nitinol

    Energy Technology Data Exchange (ETDEWEB)

    Afzal, Naveed [Centre for Advanced Studies in Physics, GC University, Lahore (Pakistan); Ghauri, I.M., E-mail: ijaz.phys@gmail.co [Centre for Advanced Studies in Physics, GC University, Lahore (Pakistan); Mubarik, F.E.; Amin, F. [Centre for Advanced Studies in Physics, GC University, Lahore (Pakistan)

    2011-01-01

    The present investigation deals with the study of mechanical behavior of proton beam irradiated nitinol at room temperature. The specimens in austenitic phase were irradiated over periods of 15, 30, 45 and 60 min at room temperature using 2 MeV proton beam obtained from Pelletron accelerator. The stress-strain curves of both unirradiated and irradiated specimens were obtained using a universal testing machine at room temperature. The results of the experiment show that an intermediate rhombohedral (R) phase has been introduced between austenite and martensite phase, which resulted in the suppression of direct transformation from austenite to martensite (A-M). Stresses required to start R-phase ({sigma}{sub RS}) and martensitic phase ({sigma}{sub MS}) were observed to decrease with increase in exposure time. The hardness tests of samples before and after irradiation were also carried out using Vickers hardness tester. The comparison reveals that the hardness is higher in irradiated specimens than that of the unirradiated one. The increase in hardness is quite sharp in specimens irradiated for 15 min, which then increases linearly as the exposure time is increased up to 60 min. The generation of R-phase, variations in the transformation stresses {sigma}{sub RS} and {sigma}{sub MS} and increase in hardness of irradiated nitinol may be attributed to lattice disorder and associated changes in crystal structure induced by proton beam irradiation.

  1. Status of food irradiation in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, O.K. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-12-31

    Research on food irradiation in Brazil started in 1968 at the Center of Nuclear Energy for Agriculture (CENA), Piracicaba, Sao Paulo. At the Institute of Nuclear and Energy Research (IPEN-CNEN/SP), Sao Paulo, Sao Paulo, research on detection of irradiated foods is in progress. In 1973, the Brazilian government established a regulation about food irradiation. Nowadays, the products authorized to be irradiated are: rice, poultry, fish and fish products, potatoes, onions, avocados, persimmons, pineapples, wheat flour, maize, beans, spices, tomatoes, guavas, oranges, lemons, strawberries, mangoes, melons and papayas. The other recommended products to be approved in the future are: acerolas, apples, beans (dose > 1 kGy), beef, blueberries, cherries, cheeses, coffee, figs, fresh guaranas, garlics, grapefruits, grapes, mushrooms, nuts and pork. Today, there is only one commercial facility for irradiation services in the country, the Empresa Brasileira de Radiacoes Ltda. (EMBRARAD). This company operates a Nordion JS-7500 irradiator, with a present activity of about 1,000 kCi, designed for sterilizing medical devices. It also irradiates spices, dried foods, gemstones, cosmetics, wood and raw materials for pharmaceuticals. The plant operates 24 hours a day and the spices and dried foods represent 15% of the business. Powder of guarana seeds is irradiated also for exportation. There are two other commercial facilities for radiation sterilization in Brazil, operating exclusively for their own production. (J.P.N.)

  2. Schedule and status of irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has one irradiation experiment in reactor and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  3. Calibration of TL detectors for skin entrance dose postal quality control in dental radiology

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Luiz A.R. da; Marechal, Maria H.H.; Feital, Joao C.S. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil). Dept. de Fisica Medica; Carlos, Marcia T. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    2001-07-01

    The Institute of Radiation Protection and Dosimetry (IRD/CNEN) started its postal programme of dose assessment in dental radiology in Rio de Janeiro State in 1980. This programme is based on a kit containing two TLD-100 thermoluminescent (TL) chip detectors positioned on both sides of an aluminium foil with a thickness of 3 mm and a radiograph film. It is able to estimate the entrance exposure, the total filtration of the X-rays equipment and the irradiation field size. Since 1998 the new regulation on radiation protection requires the evaluation of the entrance skin dose (ESD) to be compared with the diagnostic reference levels. This work describes the calibration of 1000 new TLD-100 TL chips detectors for the IRD programme of dental radiology, including the determination of entrance skin dose calibration factors in order to implement this new quantity. A TL system quality control programme, that is going to be implemented, is also presented. (author)

  4. AGR-1 Post Irradiation Examination Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

  5. Hypopituitarism after irradiation in children

    Energy Technology Data Exchange (ETDEWEB)

    Wara, W.M.; Richards, G.E.; Grumbach, M.M. Kaplan, S.L.; Sheline, G.E.; Conte, F.A.

    1977-01-01

    Nine children were referred to the University of California Medical Center, San Francisco, for growth evaluation. Each had received conventional radiation doses to the head for tumors not involving the hypothalamus or pituitary, and demonstrated clinical and laboratory evidence of hormonal deficiencies several years after treatment. Six had significant height retardation. Growth hormone deficiency was documented in all by lack of response to provocative insulin, arginine, and/or L-dopa stimulation. ACTH function was evaluated by plasma cortisol response to insulin hypoglycemia in 7; one had a subnormal response. Plasma gonadotropins were measured after lutenizing hormone releasing factor (LRF) in 7 patients; only one had an abnormal response for age and stage of sexual maturation. Foresight in treatment planning and careful follow-up of patients receiving irradiation to the head is critical, since hypothalamic-pituitary deficiencies which may occur insidiously over many years, can largely be compensated.

  6. RERTR-7 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-7A, was designed to test several modified fuel designs to target fission densities representative of a peak low enriched uranium (LEU) burnup in excess of 90% U-235 at peak experiment power sufficient to generate a peak surface heat flux of approximately 300 W/cm2. The RERTR-7B experiment was designed as a high power test of 'second generation' dispersion fuels at peak experiment power sufficient to generate a surface heat flux on the order of 230 W/cm2.1 The following report summarizes the life of the RERTR-7A and RERTR-7B experiments through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.

  7. AFIP-2 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Danielle M Perez

    2011-04-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-2 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-2 experiment was fabricated by friction bond (FB) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-2 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results. The safety analyses performed for AFIP-2 are summarized in Table 5 of the following report.

  8. AFIP-2 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Danielle M Perez; M. A. Lillo; G. S. Chang; G. A. Roth; N. E. Woolstenhulme; D. M. Wachs

    2011-05-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-2 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-2 experiment was fabricated by friction bond (FB) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-2 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results. The safety analyses performed for AFIP-2 are summarized in Table 5 of the following report.

  9. Osteonecrosis of acetabulum after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Gintaro; Matuda, Tatsuo; Takeuchi, Norihiro; Itoh, Haruo [Tokyo Koseinenkin Hospital (Japan)

    1996-11-01

    A case of osteonecrosis 8 years post irradiation was reported. The 70 years old female patient who, 8 years ago, received abdominal hysterectomy due to cervical cancer and then radiotherapy of 92.1 Gy within about 1.5 mo, had a pain at the left hip joint with a slight elevation of ALP. The roentgenography showed the fracture and callus of the left acetabulum; bone scintigraphy, a high accumulation of {sup 99m}Tc at the site; CT, abnormal fracture; MRI, low bright T1-weighted image and equi-bright T2-image; and MRI with Gd-DTPA, enhanced image. The hip joint was surgically reconstructed with cement (THR). Surgical and histopathological findings confirmed osteonecrosis without tumoral finding and the lesion was considered radiogenic. (K.H.)

  10. Modeling of Irradiation Hardening of Polycrystalline Materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongsheng; Zbib, Hussein M.; Garmestani, Hamid; Sun, Xin; Khaleel, Mohammad A.

    2011-09-14

    High energy particle irradiation of structural polycrystalline materials usually produces irradiation hardening and embrittlement. The development of predict capability for the influence of irradiation on mechanical behavior is very important in materials design for next generation reactors. In this work a multiscale approach was implemented to predict irradiation hardening of body centered cubic (bcc) alpha-iron. The effect of defect density, texture and grain boundary was investigated. In the microscale, dislocation dynamics models were used to predict the critical resolved shear stress from the evolution of local dislocation and defects. In the macroscale, a viscoplastic self-consistent model was applied to predict the irradiation hardening in samples with changes in texture and grain boundary. This multiscale modeling can guide performance evaluation of structural materials used in next generation nuclear reactors.

  11. Cost effective alternative to low irradiance measurements

    Science.gov (United States)

    Oleary, Scott T.

    1988-01-01

    Martin Marietta's Space Simulation Laboratory (SSL) has a Thermal Environment Simulator (TES) with 56 individually controlled heater zones. The TES has a temperature range of approximately minus 129 C to plus 149 C. Because of the ability of TES to provide complex irradiance distributions, it is necessary to be able to measure a wide range of irradiance levels. SSL currently uses ambient temperature controlled radiometers with the capacity to measure sink irradiance levels of approximately 42.6 mw/sq cm, sink temperature equals 21 C and up. These radiometers could not be used to accurately measure the lower irradiance levels of the TES. Therefore, it was necessary to obtain a radiometer or develop techniques which could be used to measure lower irradiance levels.

  12. Significance of primary irradiation creep in graphite

    Energy Technology Data Exchange (ETDEWEB)

    Erasmus, Christiaan, E-mail: christiaan.erasmus@gmail.com [Pebble Bed Modular Reactor (Proprietary) Limited, PO Box 9396, Centurion 0046 (South Africa); Kok, Schalk [Advanced Mathematical Modelling, CSIR Modelling and Digital Science, Pretoria 0001 (South Africa); Hindley, Michael P. [Pebble Bed Modular Reactor (Proprietary) Limited, PO Box 9396, Centurion 0046 (South Africa)

    2013-05-15

    Traditionally primary irradiation creep is introduced into graphite analysis by applying the appropriate amount of creep strain to the model at the initial time-step. This is valid for graphite components that are subjected to high fast neutron flux fields and constant stress fields, but it does not allow for the effect of movement of stress locations around a graphite component during life, nor does it allow primary creep to be applied rate-dependently to graphite components subject to lower fast neutron flux. This paper shows that a differential form of primary irradiation creep in graphite combined with the secondary creep formulation proposed by Kennedy et al. performs well when predicting creep behaviour in experimental samples. The significance of primary irradiation creep in particular in regions with lower flux is investigated. It is shown that in low flux regions with a realistic operating lifetime primary irradiation creep is significant and is larger than secondary irradiation creep.

  13. Identification of irradiated pepper with comet assay

    Energy Technology Data Exchange (ETDEWEB)

    Prieto Miranda, Enrique Fco.; Moreno Alvarez, Damaris L.; Carro Palacio, Sandra [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear. (CEADEN), Ciudad de La Habana (Cuba)]. E-mail: efprieto@ceaden.edu.cu; damaris@ceaden.edu.cu; Iglesia Enriquez, Isora [Instituto de Investigacion para la Industria Alimenticia (IIIA), Ciudad de La Habana (Cuba)

    2007-07-01

    The treatment of foods with ionizing radiations is a technological process utilized in order to increase the hygienic quality and the storage time of the foods. Several methods of detection of irradiated foods have been recommended. The comet assay of DNA is one fast and economical technique for the qualitative identification of irradiated foods. The objective of the present paper was to identify with the comet assay technique the modifications of the DNA molecule of irradiated pepper storage at environment and refrigeration temperatures and different post-irradiation times for different absorbed dose values, (0.1, 0.3 and 0.5 kGy). It was demonstrated that for the high absorbed dose values was observed a greater break into fragments of the DNA molecule, which shows the application of this technique for the identification of irradiated foods. (author)

  14. ATF Neutron Irradiation Program Technical Plan

    Energy Technology Data Exchange (ETDEWEB)

    Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.

  15. AGC-1 Irradiation Experiment Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Bratton

    2006-05-01

    The Advanced Graphite Capsule (AGC) irradiation test program supports the acquisition of irradiated graphite performance data to assist in the selection of the technology to be used for the VHTR. Six irradiations are planned to investigate compressive creep in graphite subjected to a neutron field and obtain irradiated mechanical properties of vibrationally molded, extruded, and iso-molded graphites for comparison. The experiments will be conducted at three temperatures: 600, 900, and 1200°C. At each temperature, two different capsules will be irradiated to different fluence levels, the first from 0.5 to 4 dpa and the second from 4 to 7 dpa. AGC-1 is the first of the six capsules designed for ATR and will focus on the prismatic fluence range.

  16. ATF Neutron Irradiation Program Technical Plan

    Energy Technology Data Exchange (ETDEWEB)

    Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.

  17. SORCE Level 3 Total Solar Irradiance Daily Average V016

    Data.gov (United States)

    National Aeronautics and Space Administration — The Total Solar Irradiance (TSI) data set SOR3TSID contains the total solar irradiance (a.k.a solar constant) data collected by the Total Irradiance Monitor (TIM)...

  18. Embrittlement of irradiated F82H in the absence of irradiation hardening

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L. [Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States)], E-mail: kluehrl@ornl.gov; Shiba, K. [Japan Atomic Energy Agency, Toki-Mura, Ibaraki (Japan); Sokolov, M.A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States)

    2009-04-30

    Neutron irradiation of 7-12% Cr ferritic/martensitic steels below 425-450 deg. C produces microstructural defects and precipitation that cause an increase in yield stress. This irradiation hardening causes embrittlement, which is observed in a Charpy impact or fracture toughness test as an increase in the ductile-brittle transition temperature. Based on observations that show little change in strength in steels irradiated above 425-450 deg. C, the general conclusion has been that no embrittlement occurs above these temperatures. In a recent study of F82H steel, significant embrittlement was observed after irradiation at 500 deg. C, but no hardening occurred. This embrittlement is apparently due to irradiation-accelerated Laves-phase precipitation. Observations of the embrittlement of F82H in the absence of irradiation hardening have been examined and analyzed with thermal-aging studies and computational thermodynamics calculations to illuminate and understand the embrittlement during irradiation.

  19. Thermoluminescent response of LiF: Mg, Cu, P (GR-200) below an electron beam of 6 MeV; Respuesta termoluminiscente de LiF: Mg, Cu, P (GR-200) ante un haz de electrones de 6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Torijano C, E.F.S.; Azorin N, J. [Universidad Autonoma Metropolitana-lztapalapa, Av. San Rafael Atlixco 87. Col. Vicentina, 09340 Mexico D.F. (Mexico); Villasenor N, I.; Lujan C, P.J. [Hospital General de Mexico, Balmis 148, 06726 Mexico D.F. (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria del IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D.F. (Mexico)

    2007-07-01

    Full text: In this work the experimental results of studying the thermoluminescent response (TL) of LiF:Mg,Cu,P (GR-200) previously irradiated with 6 MeV electrons are presented. The electrons beam was generated by a Lineal Accelerator VARIAN I for medical use. The lineal accelerator is installed in the General Hospital of Mexico (HGM). A lot of 25 thermoluminescent dosemeters (DTL) was used. The mass and volume of each one of them were determined. Obtaining a variation of 14% in standard deviation (SD). The DTLs were irradiated to an energy of 6 MeV. The dose given to the DTL was of 50 c Gy. The linearity of the response of the GR-200 also was determined. (Author)

  20. Irradiation creep of dispersion strengthened copper alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovsky, A.S.; Barabash, V.R.; Fabritsiev, S.A. [and others

    1997-04-01

    Dispersion strengthened copper alloys are under consideration as reference materials for the ITER plasma facing components. Irradiation creep is one of the parameters which must be assessed because of its importance for the lifetime prediction of these components. In this study the irradiation creep of a dispersion strengthened copper (DS) alloy has been investigated. The alloy selected for evaluation, MAGT-0.2, which contains 0.2 wt.% Al{sub 2}O{sub 3}, is very similar to the GlidCop{trademark} alloy referred to as Al20. Irradiation creep was investigated using HE pressurized tubes. The tubes were machined from rod stock, then stainless steel caps were brazed onto the end of each tube. The creep specimens were pressurized by use of ultra-pure He and the stainless steel caps subsequently sealed by laser welding. These specimens were irradiated in reactor water in the core position of the SM-2 reactors to a fluence level of 4.5-7.1 x 10{sup 21} n/cm{sup 2} (E>0.1 MeV), which corresponds to {approx}3-5 dpa. The irradiation temperature ranged from 60-90{degrees}C, which yielded calculated hoop stresses from 39-117 MPa. A mechanical micrometer system was used to measure the outer diameter of the specimens before and after irradiation, with an accuracy of {+-}0.001 mm. The irradiation creep was calculated based on the change in the diameter. Comparison of pre- and post-irradiation diameter measurements indicates that irradiation induced creep is indeed observed in this alloy at low temperatures, with a creep rate as high as {approx}2 x 10{sup {minus}9}s{sup {minus}1}. These results are compared with available data for irradiation creep for stainless steels, pure copper, and for thermal creep of copper alloys.

  1. Saturation behavior of irradiation hardening in F82H irradiated in the HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T. [Blanket Engineering Group, Japan Atomic Energy Agency, Naka, Ibaraki (Japan); Shiba, K.; Tanigawa, H.; Ando, M. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Klueh, R.L. [Oak Ridge National Laboratory, TN (United States); Stoller, R. [ORNL - Oak Ridge National Laboratory, Materials Science and Technology Div., Oak Ridge, AK TN (United States)

    2007-07-01

    Full text of publication follows: Post irradiation tensile tests on reduced activation ferritic/martensitic steel, F82H have been conducted over the past two decades using Japan Materials Testing Reactor (JMTR) of JAEA, and Fast Flux Testing Facility (FFTF) of PNNL and High Flux Isotope Reactor (HFIR) of ORNL, USA, under Japan/US collaboration programs. According to these results, F82H does not demonstrate irradiation hardening above 673 K up to 60 dpa. The current study has been concentrated on hardening behavior at temperature around 573 K. A series of low temperature irradiation experiment has been conducted at the HFIR under the international collaborative research between JAEA/US-DOE. In this collaboration, the irradiation condition is precisely controlled by the well matured capsule designing and instrumentation. This paper summarizes recent results of the irradiation experiments focused on F82H and its modified steels compared with the irradiation properties database on F82H. Post irradiation tensile tests have been conducted on the F82H and its modified steels irradiated at 573 K and the dose level was up to 25 dpa. According to these results, irradiation hardening of F82H is saturated by 9 dpa and the as-irradiated 0.2 % proof stress is less than 1 GPa at ambient temperature. The deterioration of total elongation was also saturated by 9 dpa irradiation. The ductility of some modified steels which showed larger total elongation than that of F82H before irradiation become the same level as that of standard F82H steel after irradiation, even though its magnitude of irradiation hardening is smaller than that of F82H. This suggests that the more ductile steel demonstrates the more ductility loss at this temperature, regardless to the hardening level. The difference in ductility loss behavior between various tensile specimens will be discussed as the ductility could depend on the specimen dimension. (authors)

  2. History and prospects of irradiation treatment of sewage sludge

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper presents a survey of irradiation treatment of sewage sludge in the world.Since the first sludge irradiation plant was built in Geiselbullach, West Germany in 1973 which used 60Co as irradiation source, many sludge irradiators were constructed in USA, India, Japan, Canada, Poland and so on, which used 60Co, 137Cs or electron beam as irradiation sources.Some basic researches on irradiation treatment of sewage sludge are, respectively, reviewed, including optimization of irradiation parameters, synergistic effect of radiation with heat, oxygenation, irradiation-composting and potential applications of treated sludge.Some proposals have been suggested for further development of this technology.

  3. Dosimetric behavior of thermoluminescent dosimeters at low doses in diagnostic radiology; Comportamiento dosimetrico de dosimetros termoluminiscentes a bajas dosis en radiodiagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Del Sol F, S.; Garcia S, R.; Guzman M, J.; Sanchez G, D.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Ramirez R, G. [Hospital Juarez de Mexico, Av. IPN 5160, Col. Magdalena de las Salinas, 07760 Mexico D. F. (Mexico); Gaona, E., E-mail: susi2489@hotmail.com [Universidad Autonoma Metropolitana, Unidad Xochimilco, Calz. del Hueso 1100, Col. Villa Quietud, 04960 Mexico D. F. (Mexico)

    2015-10-15

    Thermoluminescent (Tl) characteristics of TLD-100, LiF:Mg,Cu,P, and CaSO{sub 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{sub 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{sub 4}: Dy). (Author)

  4. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Kieu N. Lan [Post Harvest Technology Inst. of Vietnam (Viet Nam)

    2000-09-01

    Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by {gamma}-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

  5. Irradiation of onions on a large scale

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Koji; Hayashi, Toru; Uozumi, J.; Sugimoto, Toshio; Aoki, Shohei

    1984-03-01

    A large number of onions of var. Kitamiki and Ohotsuku were irradiated in September followed by storage at 0 deg C or 5 deg C. The onions were shifted from cold-storage facilities to room temperature in mid-March or in mid-April in the following year. Their sprouting, rooting, spoilage characteristics and sugar content were observed during storage at room temperature. Most of the unirradiated onions sprouted either outside or inside bulbs during storage at room temperature, and almost all of the irradiated ones showed small buds with browning inside the bulb in mid-April irrespective of the storage temperature. Rooting and/or expansion of bottom were observed in the unirradiated samples. Although the irradiated materials did not have root, they showed expansion of bottom to some extent. Both the irradiated and unirradiated onions spoiled slightly unless they sprouted, and sprouted onions were easily spoiled. There was no difference in the glucose content between the unirradiated and irradiated onions, but the irradiated ones yielded higher sucrose content when stored at room temperature. Irradiation treatment did not have an obvious effect on the quality of freeze-dried onion slices. (author).

  6. The Next Spaceflight Solar Irradiance Sensor: TSIS

    Science.gov (United States)

    Kopp, Greg; Pilewskie, Peter; Richard, Erik

    2016-05-01

    The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

  7. Irradiation Behavior in High Entropy Alloys

    Institute of Scientific and Technical Information of China (English)

    Song-qin XIA; Zhen WANG; Teng-fei YANG; Yong ZHANG

    2015-01-01

    As an increasing demand of advanced nuclear fission reactors and fusion facilities, the key requirements for the materials used in advanced nuclear systems should encompass superior high temperature property, good behavior in corrosive environment, and high irradiation resistance, etc. Recently, it was found that some selected high entropy alloys (HEAs) possess excellent mechanical properties at high temperature, high corrosion resistance, and no grain coarsening and self-healing abil-ity under irradiation, especially, the exceptional structural stability and lower irradiation-induced volume swelling, compared with other conventional materials. Thus, HEAs have been considered as the potential nuclear materials used for future ifssion or fusion reactors, which are designed to operate at higher temperatures and higher radiation doses up to several hundreds of displacement per atom (dpa). An insight into the irradiation behavior of HEAs was given, including fundamental researches to investigate the irradiation-induced phase crystal structure change and volume swelling in HEAs. In summary, a brief overview of the irradiation behavior in HEAs was made and the irradiation-induced structural change in HEAs may be relatively insensi-tive because of their special structures.

  8. AGC-1 Post Irradiation Examination Status

    Energy Technology Data Exchange (ETDEWEB)

    David Swank

    2011-09-01

    The Next Generation Nuclear Plant (NGNP) Graphite R&D program is currently measuring irradiated material property changes in several grades of nuclear graphite for predicting their behavior and operating performance within the core of new Very High Temperature Reactor (VHTR) designs. The Advanced Graphite Creep (AGC) experiment consisting of six irradiation capsules will generate this irradiated graphite performance data for NGNP reactor operating conditions. All six AGC capsules in the experiment will be irradiated in the Advanced Test Reactor (ATR), disassembled in the Hot Fuel Examination Facility (HFEF), and examined at the INL Research Center (IRC) or Oak Ridge National Laboratory (ORNL). This is the first in a series of status reports on the progress of the AGC experiment. As the first capsule, AGC1 was irradiated from September 2009 to January 2011 to a maximum dose level of 6-7 dpa. The capsule was removed from ATR and transferred to the HFEF in April 2011 where the capsule was disassembled and test specimens extracted from the capsules. The first irradiated samples from AGC1 were shipped to the IRC in July 2011and initial post irradiation examination (PIE) activities were begun on the first 37 samples received. PIE activities continue for the remainder of the AGC1 specimen as they are received at the IRC.

  9. Oxygen delivery in irradiated normal tissue

    Energy Technology Data Exchange (ETDEWEB)

    Kiani, M.F.; Ansari, R. [Univ. of Tennessee Health Science Center, Memphis, TN (United States). School of Biomedical Engineering; Gaber, M.W. [St. Jude Children' s Research Hospital, Memphis, TN (United States)

    2003-03-01

    Ionizing radiation exposure significantly alters the structure and function of microvascular networks, which regulate delivery of oxygen to tissue. In this study we use a hamster cremaster muscle model to study changes in microvascular network parameters and use a mathematical model to study the effects of these observed structural and microhemodynamic changes in microvascular networks on oxygen delivery to the tissue. Our experimental observations indicate that in microvascular networks while some parameters are significantly affected by irradiation (e.g. red blood cell (RBC) transit time), others remain at the control level (e.g. RBC path length) up to 180 days post-irradiation. The results from our mathematical model indicate that tissue oxygenation patterns are significantly different in irradiated normal tissue as compared to age-matched controls and the differences are apparent as early as 3 days post irradiation. However, oxygen delivery to irradiated tissue was not found to be significantly different from age matched controls at any time between 7 days to 6 months post-irradiation. These findings indicate that microvascular late effects in irradiated normal tissue may be due to factors other than compromised tissue oxygenation. (author)

  10. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  11. Rheological changes in irradiated chicken eggs

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Lucia F. S.; Del Mastro, Nelida L

    1998-06-01

    Pathogenic bacteria may cause foodborne illnesses. Humans may introduce pathogens into foods during production, processing, distribution and or preparation. Some of these microorganisms are able to survive conventional preservation treatments. Heat pasteurization, which is a well established and satisfactory means of decontamination/disinfection of liquid foods, cannot efficiently achieve a similar objective for solid foods. Extensive work carried out worldwide has shown that irradiation is efficient in eradicating foodborne pathogens like Salmonella spp. that can contaminate poultry products. In this work Co-60 gamma irradiation was applied to samples of industrial powder white, yolk and whole egg at doses between 0 and 25 kGy. Samples were rehydrated and the viscosity measured in a Brookfield viscosimeter, model DV III at 5, 15 and 25 degree sign C. The rheological behaviour among the various kinds of samples were markedly different. Irradiation with doses up to 5 kGy, known to reduced bacterial contamination to non-detectable levels, showed almost no variation of viscosity of irradiated egg white samples. On the other hand, whole or yolk egg samples showed some changes in rheological properties depending on the dose level, showing the predominance of whether polimerization or degradation as a result of the irradiation. Additionally, irradiation of yolk egg powder reduced yolk color as a function of the irradiation exposure implemented. The importance of these results are discussed in terms of possible industrial applications.

  12. Spectroscopic investigation of UV irradiated enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Ware, D.L.; Hibbard, L.B. (Spelman College, Atlanta, GA (United States))

    1993-01-01

    Trptophan (Trp) undergoes photolysis when exposed to light in the near UV region. The enzyme systems horse liver alcohol dehydrogenase (HLAD) and glyceraldehyde 3-phosphate dehydrogenase (G3PDH), which contain two and three Trps respectively, were chosen for analysis of Trp photolysis. Aqueous solutions of HLAD and G3PDH were irradiated at either 295 or 335nm with a xenon lamp. Tryptophan fluorescence was monitored at half hour intervals for two hours in the case of HLAD and one hour in the case of G3PDH. The decrease in fluorescence from 295 irradiation was compared to the fluorescence decrease from 335 irradiation and was found to be similar for both the HLAD and G3PDH samples irradiated at 295nm and for both samples irradiated at 335nm. It was found that, for HLAD, the 295 irradiation caused a decrease in fluorescence of 90% as compared to a decrease of only 12% of 335nm. Enzymatic assays were then performed to determine the enzymatic activity before and after irradiation.

  13. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  14. Cell death pathways in directly irradiated cells and cells exposed to medium from irradiated cells.

    Science.gov (United States)

    Jella, Kishore Kumar; Garcia, Amaya; McClean, Brendan; Byrne, Hugh J; Lyng, Fiona M

    2013-03-01

    The aim of this study was to compare levels of apoptosis, necrosis, mitotic cell death and senescence after treatment with both direct radiation and irradiated cell conditioned medium. Human keratinocytes (HaCaT cell line) were irradiated (0.005, 0.05 and 0.5 Gy) using a cobalt 60 teletherapy unit. For bystander experiments, the medium was harvested from donor HaCaT cells 1 hour after irradiation and transferred to recipient HaCaT cells. Clonogenic assay, apoptosis, necrosis, mitotic cell death, senescence and cell cycle analysis were measured in both directly irradiated cells and bystander cells A reduction in cell survival was observed for both directly irradiated cells and irradiated cell conditioned medium (ICCM)-treated cells. Early apoptosis and necrosis was observed predominantly after direct irradiation. An increase in the number of cells in G2/M phase was observed at 6 and 12 h which led to mitotic cell death after 72 h following direct irradiation and ICCM treatment. No senescence was observed in the HaCaT cell line following either direct irradiation or treatment with ICCM. This study has shown that directly irradiated cells undergo apoptosis, necrosis and mitotic cell death whereas ICCM-treated cells predominantly undergo mitotic cell death.

  15. Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

    1998-05-01

    The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

  16. Oxygen intake in ion irradiated fullerene films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Amit [Department of Nanosciences, Neel Institute, C.N.R.S., 25 rue des Martyrs, BP166 38042 Grenoble Cedex 9 (France); Materials Science Group, Inter University Accelerator Centre, P.O. Box 10502, New Delhi 110 067 (India)], E-mail: amit.kumar@grenoble.cnrs.fr; Khan, S.A. [Materials Science Group, Inter University Accelerator Centre, P.O. Box 10502, New Delhi 110 067 (India); Kumar, Manvendra [Physics Department, Allahabad University, P.O. Box 211002 (India); Agarwal, D.C. [RBS College, Agra (India); Singh, Fouran; Tripathi, A. [Materials Science Group, Inter University Accelerator Centre, P.O. Box 10502, New Delhi 110 067 (India); Govind; Shivaprasad, S.M. [Surface Physics and Nanostructures Group, NPL, New Delhi 110 060 (India); Salomon, J.; Pichon, L. [C2RMF, Palais du Louvre, 75001 Paris (France); Pivin, J.C. [CSNSM, 91405 Orsay Campus (France); Avasthi, D.K. [Department of Nanosciences, Neel Institute, C.N.R.S., 25 rue des Martyrs, BP166 38042 Grenoble Cedex 9 (France)

    2008-04-15

    The present work reports the change in the oxygen content in energetic ion irradiated fullerene films. The oxygen contents in irradiated films have been studied using on-line elastic recoil detection analysis (ERDA) and off-line X-ray photo electron emission (XPS) and nuclear reaction analysis (NRA) techniques. The XPS and NRA techniques show that the oxygen content increases with ion fluence, whereas on-line ERDA measurements reveal that the oxygen content decreases with ion fluence. These experiments give clear evidence that oxygen content in irradiated films increases after exposure to the atmospheric oxygen.

  17. Electromechanical engineering aspects of irradiator design

    Energy Technology Data Exchange (ETDEWEB)

    Etienne, J.C.; Buyle, R.

    1984-01-01

    IRE, Institut National des Radioelements at Fleurus, has been irradiating foodstuffs since 1979. The steadily-increasing demands of the food industry led IRE to design and install a second, different type of irradiator. Selection criteria for choosing between the different alternatives or possibilities are given based on the primary consideration that a contract food irradiator must be able to provide a service in accordance with the requirements of his customers. The principal components - the radiation source geometry, the transport system and the control systems - are described. The choice of the major electromechanical components is discussed taking into account their susceptibility to radiation damage.

  18. Identification of irradiated crab using EPR

    Energy Technology Data Exchange (ETDEWEB)

    Maghraby, A. [Radiation Dosimetry Department, National Institute for Standards (NIS), Ministry of Scientific Research, Haram, 12211- Giza, P.O. Box: 136 (Egypt)]. E-mail: maghrabism@yahoo.com

    2007-02-15

    EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response.

  19. RERTR-12 Insertion 2 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Perez; G. S. Chang; D. M. Wachs; G. A. Roth; N. E. Woolstenhulme

    2012-09-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

  20. Green coffee decontamination by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nemtanu, Monica R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)]. E-mail: monica@infim.ro; Brasoveanu, Mirela [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania); Grecu, Maria Nicoleta [National Institute for Materials Physics, RO 77 125, Bucharest-Magurele (Romania); Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)

    2005-10-15

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties.