WorldWideScience

Sample records for irradiation studies monitoring

  1. Reference manual on the IAEA JRQ correlation monitor steel for irradiation damage studies

    2001-07-01

    The objective of this report is to provide information on the mechanical properties of the ASTM A533 grade B class 1 steel that was designated as 'JRQ reference steel' and for many years served as a radiation/mechanical property correlation monitor in a number of international and national studies of irradiation embrittlement of reactor pressure vessel steel. This report provides the most comprehensive listing of material test data obtained on the JRQ manufacturing history and material properties in the initial, and as delivered condition during the implementation of two IAEA co-ordinated research projects (CRPs) on behaviour of reactor pressure vessel steels under neutron irradiation

  2. Intensive irradiation studies, monitoring and commissioning data analysis on the ATLAS MDT chambers

    AUTHOR|(CDS)2071390; Susinno, Giancarlo

    2007-01-01

    The ATLAS MDT chambers have been extensively studied, starting from irradiation test to commissioning activities. First, a detailed description of high rate and high background tests is given. These tests have been carried out on a small ATLAS-like MDT chamber, by the Cosenza and Roma TRE groups. The precision tracking chambers of the muon spectrometer, in fact, have to operate for more than 10 years in the harsh LHC background, due mainly to low energy neutrons and photons. Aging effects, such as the deterioration of the tube themselves can appear and difficulties in pattern recognition and tracking may occur. Moreover an upgrade to Super-LHC is foreseen. Then, there is an accurate description of the MDTGnam package, the official software for the on-line monitoring of MDT performances. When dealing with a complex apparatus, such as the ATLAS experiment, an on-line monitoring system is a fundamental tool. The GNAM project, developed by Cosenza, Pavia, Pisa and Napoli groups, is a monitoring framework to be us...

  3. Monitoring pathogens from irradiated agriculture products

    Butterweck, J.S.

    1990-01-01

    The final food and environmental safety assessment of agriculture product irradiation can only be determined by product history. Product history will be used for future research and development, regulations, commercial practices and implementation of agriculture and food irradiation on a regional basis. The commercial irradiator treats large varieties and amounts of products that are used in various environments. it, in time, will generate a large data base of product history. Field product monitoring begins when food irradiation progresses from the pilot/demonstration phase to the commercial phase. At that time, it is important that there be in place a monitoring system to collect and analyze field data. The systems managers, public health authorities and exotic disease specialists will use this information to assess the reduction of food pathogens on the populace and the environment. (author)

  4. Irradiation monitoring of spices by chemiluminescence method

    Bhatti, K.A.; Khan, H.M.; Sattar, A.; Ahmad, A.

    2001-01-01

    Some spices (cumin, coriander, black pepper and red pepper), commonly used due to their specific aroma and nutritional value were studied using chemiluminescence (CL) method to test whether the food has been irradiated or not. The spices were ground to different mesh sizes and subjected to gamma ray doses of 2.5, 5.0, 7.5 and 10 Kgy. The effect of radiation doses and particle size on the CL response of irradiated and un-irradiated samples was checked using luminol and lucigenin sensitizers. The storage experiment was also performed for all spices with both the sensitizers in order to pick the suitable sensitizer for CL study. During this study Co-60 gamma ray source and Bio-orbit 1250 luminometer were used after precise calibration

  5. Studies of blood irradiator application

    Li Wenhong; Lu Yangqiao

    2004-01-01

    Transfusion is an important means for medical treatment, but it has many syndromes such as transfusion-associated graft-versus-host disease, it's occurrence rate of 5% and above 90% death-rate. Now many experts think the only proven method is using blood irradiator to prevent this disease. It can make lymphocyte of blood product inactive, so that it can not attack human body. Therefore, using irradiation blood is a trend, and blood irradiator may play an important role in medical field. This article summarized study of blood irradiator application, including the meaning of blood irradiation, selection of the dose for blood irradiation and so on

  6. High-resolution global irradiance monitoring from photovoltaic systems

    Buchmann, Tina; Pfeilsticker, Klaus; Siegmund, Alexander; Meilinger, Stefanie; Mayer, Bernhard; Pinitz, Sven; Steinbrecht, Wolfgang

    2016-04-01

    Reliable and regional differentiated power forecasts are required to guarantee an efficient and economic energy transition towards renewable energies. Amongst other renewable energy technologies, e.g. wind mills, photovoltaic systems are an essential component of this transition being cost-efficient and simply to install. Reliable power forecasts are however required for a grid integration of photovoltaic systems, which among other data requires high-resolution spatio-temporal global irradiance data. Hence the generation of robust reviewed global irradiance data is an essential contribution for the energy transition. To achieve this goal our studies introduce a novel method which makes use of photovoltaic power generation in order to infer global irradiance. The method allows to determine high-resolution temporal global irradiance data (one data point every 15 minutes at each location) from power data of operated photovoltaic systems. Due to the multitude of installed photovoltaic systems (in Germany) the detailed spatial coverage is much better than for example only using global irradiance data from conventional pyranometer networks (e.g. from the German Weather Service). Our designated method is composed of two components: a forward component, i.e. to conclude from predicted global irradiance to photovoltaic (PV) power, and a backward component, i.e. from PV power with suitable calibration to global irradiance. The forward process is modelled by using the radiation transport model libRadtran (B. Mayer and A. Kylling (1)) for clear skies to obtain the characteristics (orientation, size, temperature dependence, …) of individual PV systems. For PV systems in the vicinity of a meteorological station, these data are validated against calibrated pyranometer readings. The forward-modelled global irradiance is used to determine the power efficiency for each photovoltaic system using non-linear optimisation techniques. The backward component uses the power efficiency

  7. Determination of irradiation temperature using SiC temperature monitors

    Maruyama, Tadashi; Onose, Shoji

    1999-01-01

    This paper describes a method for detecting the change in length of SiC temperature monitors and a discussion is made on the relationship between irradiation temperature and the recovery in length of SiC temperature monitors. The SiC specimens were irradiated in the experimental fast reactor JOYO' at the irradiation temperatures around 417 to 645degC (design temperature). The change in length of irradiated specimens was detected using a dilatometer with SiO 2 glass push rod in an infrared image furnace. The temperature at which recovery in macroscopic length begins was obtained from the annealing intersection temperature. The results of measurements indicated that a difference between annealing intersection temperature and the design temperature sometimes reached well over ±100degC. A calibration method to obtain accurate irradiation temperature was presented and compared with the design temperature. (author)

  8. Cerenkov methodology for monitoring irradiated reactor fuel

    Nicholson, N.; Dowdy, E.J.

    1984-01-01

    Attribute measurement methods for confirming declared irradiated fuel inventories at nuclear installations under safeguards surveillance are of significant interest to inspectors. High-gain measurements of the intensity of the Cerenkov glow from exposed assemblies in water-filled storage ponds are promising for this purpose because the measured intensities depend on cooling times and burnup. We have developed a Cerenkov Measuring Device, a hand-held instrument that examines irradiated fuel assemblies in water-filled storage ponds and measures the intensity of the associated Cerenkov glow. In addition, we have developed a method for making such high-gain measurements in the presence of intense ambient light

  9. Biophysical Monitoring and dose response characteristics of irradiated hemoglobin

    Elshemey, W.M; Selim, N.S.; Desouky, O.

    2003-01-01

    The present work aims to move a step forward towards a deeper understanding of the scattering of x-ray, from lyophilized biological samples. Comparative study has been performed using LAXS and UV-visible spectrophotometry for monitoring the dose response characteristics of the hemoglobin molecule of irradiated blood. Blood samples were irradiated at doses ranging from 5 up to 100 Gy. Diluted hemoglobin solution was scanned in the UV- visible range (200-700 nm), and lyophilized hemoglobin was prepared for LAXS measurement. The radiation-induced changes in the hemoglobin structure have been evaluated. The LAXS profile of hemoglobin molecule is characterized by the presence of two peaks in the forward direction of scattering. These peaks were found to be sensitive to the variations in the molecular structure of a given sample. The obtained results suggest that the 1 s t peak, recorded at 4.65 o , is sensitive to the tertiary and quaternary structure of the globin part, while the major peak, recorded at 10.5 o , appeared to be related to its primary and secondary structure

  10. AGC-3 Experiment Irradiation Monitoring Data Qualification Final Report

    Hull, Laurence C. [Idaho National Lab. (INL), Idaho Falls, ID (United States). VHTR Technology Development Office

    2014-08-01

    The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear-grade graphite. The third experiment, Advanced Graphite Creep 3 (AGC-3), began with Advanced Test Reactor (ATR) Cycle 152B on November 27, 2012, and ended with ATR Cycle 155B on April 23, 2014. This report documents qualification of AGC-3 experiment irradiation monitoring data for use by the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Program for research and development activities required to design and license the first VHTR nuclear plant. Qualified data meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements. Trend data may not meet the requirements, but may still provide some useable information. The report documents qualification of AGC-3 experiment irradiation monitoring data following MCP-2691. This report also documents whether AGC-3 experiment irradiation monitoring data meet the requirements for data collection as specified in technical and functional requirements documents and quality assurance (QA) plans. Data handling is described showing how data are passed from the data collection experiment to the Nuclear Data Management and Analysis System (NDMAS) team. The data structure is described, including data batches, components, attributes, and response variables. The description of the approach to data qualification includes the steps taken to qualify the data and the specific tests used to verify that the data meet requirements. Finally, the current status of the data received by NDMAS from the AGC-3 experiment is presented with summarized information on test results and resolutions. This report addresses all of the irradiation monitoring data collected during the AGC-3 experiment.

  11. Research to connect the ozone monitor into irradiation system at Hanoi Irradiation Centre

    Le Van Huy; Pham Duy Duong; Nguyen Dinh Hung; Vu Quoc Dat

    2013-01-01

    Since 2006, in order to develop radiation technology, Vietnam Atomic Energy Institute has supported Hanoi Irradiation Centre a Project titled: Upgrading the irradiation facility. According to the Project, equipment have been replaced by a new one so that the facility could be suitable for treatment of products. The facility was designed and produced by the former Russia experts. Under normal operating conditions, we are protected by shielding, detection systems, and safety procedures. A system of interlocks prevents unauthorized entry into the radiation chamber when the source is exposed. However, interlocks system have not been warning and preventing ozone gas that can affect human health. So we are having an upgrade as connecting the ozone monitor into irradiation system at Hanoi Irradiation Centre. (author)

  12. Super Phenix. Monitoring of structures subject to irradiation. Neutron dosimetry measurement and calculation program

    Cabrillat, J.C.; Arnaud, G.; Calamand, D.; Manent, G.; Tavassoli, A.A.

    1984-09-01

    For the Super Phenix reactor, the evolution, versus the irradiation of the mechanical properties of the core diagrid steel is the object of studies and is particularly monitored. The specimens irradiated, now in PHENIX and will be later irradiated in SUPER PHENIX as soon as the first operating cycles. An important dosimetry program coupling calculation and measurement, is parallely carried out. This paper presents the reasons, the definition of the structure, of the development and of materials used in this program of dosimetry, as also the first results of a calculation-measurement comparison [fr

  13. EPR study on gamma-irradiated fruits dehydrated via osmosis

    Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2007-06-15

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  14. EPR study on gamma-irradiated fruits dehydrated via osmosis

    Yordanov, N.D.; Aleksieva, K.

    2007-01-01

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples

  15. EPR study on gamma-irradiated fruits dehydrated via osmosis

    Yordanov, N. D.; Aleksieva, K.

    2007-06-01

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit "sugar-like" EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  16. A study on UV irradiated HDPE

    Sang Haibo; Liu Zimin; Wu Shishan; Shen Jian

    2006-01-01

    The structure and properties of HDPE irradiated by ultraviolet (UV) in ozone atmosphere were studied by FT-IR, XPS, gel, and water contact angle test. The oxygen-containing groups such as C=O, C-O and C(=O)O were introduced onto high density polyethylene (HDPE) chains through ultraviolet irradiation in ozone atmosphere, their content increased with the UV irradiation time. Under the same UV irradiation conditions, amount of the oxygen-containing groups introduced in ozone atmosphere was more than that in air atmosphere, indicating that the speed of oxygen-containing groups introduced through UV irradiation in ozone atmosphere was faster than that in air. Therefore, HDPE could be quickly functionalized through UV irradiation in ozone atmosphere. There was no gel formed in the HDPE irradiated in ozone atmosphere. After UV irradiation, the water contact angle of HDPE decreased, and its hydrophilicity was improved, suggesting that the compatibility between the irradiated HDPE and polar polymer or inorganic fillers may be better. Compared with HDPE, the temperature of initial weight loss for irradiated HDPE decreased. The structure and properties of irradiated HDPE/CaCO 3 blend were also investigated. The results showed that the compatibility and interfacial action of the irradiated HDPE/CaCO 3 blend were improved compared to that of HDPE/CaCO 3 blend. The mechanical properties of irradiated HDPE/CaCO 3 blend increased with increasing irradiation time. (authors)

  17. Positron lifetime studies of electron irradiated copper

    Hadnagy, T.D.

    1976-01-01

    Single-crystal copper was irradiated with 4.5-MeV electrons producing simple Frenkel defects as well as a significant concentration of divacancies. Mean positron lifetime characteristics, which are sensitive to the presence of vacancies and multivacancies in copper, was monitored after isochronal anneals between 80 and 800 0 K to determine the relative change of characteristic mean lifetimes and their associated intensities. Also a study of the dependence of the mean positron lifetime on the total electron fluence was made and compared with existing theories relating these lifetimes to vacancy or multivacancy concentrations. Numerical data from curve fitting procedures using a conventional trapping model for defect-induced changes in positron lifetimes indicate that upon irradiation with 4.5-MeV electrons at 80 0 K, about 8 percent of the defects produced are divacancy units. Divacancy units appear to be several times more effective in trapping positrons than are monovacancies. Further, the experimental data suggest that the stage III annealing processes in electron-irradiated copper most probably involve the motion and removal of both monovacancies and divacancies. A conglomerate (multivacancy) unit appears to exist as a stable entity even after annealing procedures are carried out at temperatures slightly above the stage III region. Such a stable unit could serve as a nucleation center for the appearance of voids

  18. Onion irradiation - a case study

    Huebner, G.

    1988-01-01

    The irradiation of onions (Allium cepa L.) serves to prevent sprouting associated with long-term storage or transport and storage of onions in climatic conditions which stimulate sprouting. JECFI the Joint Expert Committee for Food Irradiation of FAO/IAEA/WHO, recommended the application of an irradiation dose of up to 150 Gy for sprout inhibition with onions. (author)

  19. A study of positron irradiated porous silicon

    Huang Yuanming; Xue Qing; Zhai Baogai; Xu Aijun; Liu Shewen; Yu Weizhong

    1998-01-01

    The effect of positron irradiation on photoluminescence (PL) of porous silicon has been studied. After four hour positron irradiation, the red PL spectrum of porous silicon blue shifts into greenish spectral region, and a higher energy luminescence band is introduced into this blueshifted spectrum. The fourier transform infrared absorption experiment shows that the positron irradiation can cause further oxidization of porous silicon. A possible mechanism causing this change of PL spectra after positron irradiation is suggested

  20. Assessment of gold flux monitor at irradiation facilities of MINT TRIGA MK II reactor

    Wee Boon Siong; Abdul Khalik Wood; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Md Suhaimi Elias; Nazaratul Ashifa Abd Salim

    2005-01-01

    Neutron source of MINTs TRIGA MK II reactor has been used for activation analysis for many years and neutron flux plays important role in activation of samples at various positions. Currently, two irradiation facilities namely the pneumatic transfer system and rotary rack are available to cater for short and long lived irradiation. Neutron flux variation for both irradiation facilities have been determined using gold wire and gold solution as flux monitor. However, the use of gold wire as flux monitor is costlier if compared to gold solution. The results from analysis of certified reference materials showed that gold solution as flux monitors yield satisfactory results and proved to safe cost on the purchasing of gold wire. Further experiment on self-shielding effects of gold solution at various concentrations has been carried out. This study is crucial in providing vital information on the suitable concentration for gold solution as flux monitor. In the near future, gold solution flux monitor will be applied for routine analysis and hence to improve the capability of the laboratory on neutron activation analysis. (Author)

  1. Magnetic resonance thermometry for monitoring photothermal effects of interstitial laser irradiation

    Goddard, Jessica; Jose, Jessnie; Figueroa, Daniel; Le, Kelvin; Liu, Hong; Nordquist, Robert E.; Hode, Tomas; Chen, Wei R.

    2012-03-01

    Selective photothermal interaction using dye-assisted non-invasive laser irradiation has limitations when treating deeper tumors or when the overlying skin is heavily pigmented. We developed an interstitial laser irradiation method to induce the desired photothermal effects. An 805-nm near-infrared laser with a cylindrical diffuser was used to treat rat mammary tumors by placing the active tip of the fiber inside the target tumors. Three different power settings (1.0 to 1.5 watts) were applied to treat animal tumors with an irradiation duration of 10 minutes. The temperature distributions of the treated tumors were measured by a 7.1-Tesla magnetic resonance imager using proton resonance frequency (PRF) method. Three-dimensional temperature profiles were reconstructed and assessed using PRF. This is the first time a 7.1-Tesla magnetic resonance imager has been used to monitor interstitial laser irradiation via PRF. This study provides a basic understanding of the photothermal interaction needed to control the thermal damage inside tumor using interstitial laser irradiation. It also shows that PRF can be used effectively in monitoring photothermal interaction. Our long-term goal is to develop a PRF-guided laser therapy for cancer treatment.

  2. Method for monitoring irradiated nuclear fuel using cerenkov radiation

    Caldwell, J.T.; Dowdy, E.J.; Nicholson, N.

    1983-01-01

    A method is provided for monitoring irradiated nuclear fuel inventories located in a water-filled storage pond wherein the intensity of the cerenkov radiation emitted from the water in the vicinity of the nuclear fuel is measured. This intensity is then compared with the expected intensity for nuclear fuel having a corresponding degree of irradiation exposure and time period after removal from a reactor core. Where the nuclear fuel inventory is located in an assembly having fuel pins or rods with intervening voids, the cerenkov light intensity measurement is taken at selected bright spots corresponding to the water-filled interstices of the assembly in the water storage, the waterfilled interstices acting as cerenkov light channels so as to reduce cross-talk. On-line digital analysis of an analog video signal is possible, or video tapes may be used for later measurement using a video editor and an electrometer. Direct measurement of the cerenkov radiation intensity also is possible using spot photometers pointed at the assembly

  3. Complex immunological monitoring of breast cancer patients treated postoperatively by electron beam irradiation

    Horvath, M.; Horvath, A.; Fekete, B.; Toth, J.

    1986-01-01

    To monitor the electron beam therapy some immunological parameters of breast cancer patients previously undergone surgery were tested before, during and after irradiation. Immune complex levels measured by complement consumption technique were not altered by irradiation. Killer cell activity tested in so-called antibody dependent cellular cytotoxicity (ADCC) capacity assay showed a marked decrease in some cases. Based on the phagocytic capacity of the granulocytes the patients could be divided into two groups: one with declining activity and another with rising activity: The majority of the patients (22/45) were humoral leukocyte adherence inhibition (H-LAI) negative before and during irradiation. Those showed positive H-LAI indices before electron therapy had unchanged (7/45) or decreasing (9/45) tendencies during the observation period. Further study is needed to establish the clinical relevance of these in vitro assays used by us. (orig.) [de

  4. Study of irradiation effect on curcuma polyphenols

    Rejeb, Imen

    2008-01-01

    The present study was carried out to evaluate the effect of gamma irradiation on curcumin (Curcuma Longa rhizome) component, particularly the polyphenolic fraction. Powdered rhizome was irradiated at 0, 5, 10 and 15 KGy (dose rate of 6 KGy / H). Polyphenolics were extracted and total polyphenols conent (TPC) was quantified using the Folin-Ciocalteau method. The irradiation effect was also evaluated by the HPLC technique. The chromatographic analysis showed that the irradiated and non-irradiated curcumin spectrum gave similar data. The antioxidant and antibacterial activities of the phenolic extracts were also assessed. the anti oxidative potential of the sample was evaluated using two radical scavenging methods with DPPH and ABTS. The antimicrobial analysis showed that the phenolic extracts of curcumin inhibited the growth of the studied microorganisms. Our results showed that irradiated samples were not affected in terms of polyphenols content and characteristics. (Author)

  5. Studies on the irradiated solids

    Lesueur, D.

    1988-01-01

    The 1988 progress report of the Irradiated Solids laboratory (Polytechnic School, France), is presented. The Laboratory activities concern the investigations on disordered solids (chemical or structural disorder). The disorder itself, its effects on the material physical properties and the particle-matter interactions, are investigated. The research works are performed in the following fields: solid state physics, irradiation and stoechiometric defects, and nuclear materials. The scientific reviews, the congress communications and the thesis are listed [fr

  6. AGC-3 Experiment Irradiation Monitoring Data Qualification Final Report

    Laurence Hull

    2014-10-01

    The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The third experiment, Advanced Graphite Creep 3 (AGC 3), began with Advanced Test Reactor (ATR) Cycle 152B on November 27, 2012, and ended with ATR Cycle 155B on April 23, 2014. This report documents qualification of AGC 3 experiment irradiation monitoring data for use by the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Program for research and development activities required to design and license the first VHTR nuclear plant. Qualified data meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements. Trend data may not meet the requirements, but may still provide some useable information. All thermocouples (TCs) functioned throughout the AGC 3 experiment. There was one interval between December 18, 2012, and December 20, 2012, where 10 NULL values were reported for various TCs. These NULL values were deleted from the Nuclear Data Management and Analysis System database. All temperature data are Qualified for use by the VHTR TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the VHTR TDO Program. Total gas flow was approximately 50 sccm through the AGC 3 experiment capsule. Helium gas flow was briefly increased to 100 sccm during ATR shutdowns. At the start of the AGC 3 experiment, moisture in the outflow gas line was stuck at a constant value of 335.6174 ppmv for the first cycle (Cycle 152B). When the AGC 3 experiment capsule was reinstalled in ATR for Cycle 154B, a new moisture filter was installed. Moisture data from Cycle 152B are Failed. All moisture data from the final three cycles (Cycles 154B, 155A, and 155B) are Qualified for use by the VHTR TDO Program.

  7. Study of irradiation creep of vanadium alloys

    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.

  8. AGC-4 Experiment Irradiation Monitoring Data Qualification Interim Report

    Hull, Laurence Charles

    2016-01-01

    The Graphite Technology Development Program is running a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The fourth experiment, Advanced Graphite Creep 4 (AGC 4), began with Advanced Test Reactor (ATR) cycle 157D on May 30, 2015, and has been irradiated for two cycles. The capsule was removed from the reactor after ATR cycle 158A, which ended on January 2, 2016, due to interference with another experiment. Irradiation will resume when the interfering experiment is removed from the reactor. This report documents qualification of AGC 4 experiment irradiation monitoring data for use by the Advanced Reactor Technologies (ART) Technology Development Office (TDO) Program for research and development activities required to design and license the first HTR nuclear plant. Qualified data meet the requirements for use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements and provide no useable information. Trend data may not meet all requirements, but still provide some useable information. Use of Trend data requires assessment of how any deficiencies affect a particular use of the data. All thermocouples (TCs) have functioned throughout the AGC-4 experiment. All temperature data are Qualified for use by the ART TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the ART TDO Program. Discharge gas line moisture values were consistently low during cycle 157D. At the start of cycle 158A, gas moisture briefly spiked to over 600 ppmv and then declined throughout the cycle. Moisture values are within the measurement range of the instrument and are Qualified for use by the ART TDO Program. Graphite creep specimens were subjected to one of three loads, 393, 491, or 589 lbf. For a brief period during cycle 157D between 12:19 on June 2, 2015 and 08:23 on June 11, 2015 the load cells were wired incorrectly resulting in missing

  9. AGC-4 Experiment Irradiation Monitoring Data Qualification Interim Report

    Hull, Laurence Charles [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    The Graphite Technology Development Program is running a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The fourth experiment, Advanced Graphite Creep 4 (AGC 4), began with Advanced Test Reactor (ATR) cycle 157D on May 30, 2015, and has been irradiated for two cycles. The capsule was removed from the reactor after ATR cycle 158A, which ended on January 2, 2016, due to interference with another experiment. Irradiation will resume when the interfering experiment is removed from the reactor. This report documents qualification of AGC 4 experiment irradiation monitoring data for use by the Advanced Reactor Technologies (ART) Technology Development Office (TDO) Program for research and development activities required to design and license the first HTR nuclear plant. Qualified data meet the requirements for use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements and provide no useable information. Trend data may not meet all requirements, but still provide some useable information. Use of Trend data requires assessment of how any deficiencies affect a particular use of the data. All thermocouples (TCs) have functioned throughout the AGC-4 experiment. All temperature data are Qualified for use by the ART TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the ART TDO Program. Discharge gas line moisture values were consistently low during cycle 157D. At the start of cycle 158A, gas moisture briefly spiked to over 600 ppmv and then declined throughout the cycle. Moisture values are within the measurement range of the instrument and are Qualified for use by the ART TDO Program. Graphite creep specimens were subjected to one of three loads, 393, 491, or 589 lbf. For a brief period during cycle 157D between 12:19 on June 2, 2015 and 08:23 on June 11, 2015 the load cells were wired incorrectly resulting in missing

  10. Booster Long 13 irradiation studies

    Leveling, A.; Mokhov, N.; Moore, C.D.; /Fermilab

    1998-06-01

    Extraction from the Booster to the Main Ring occurred at Long Straight 13. The nature of the extraction process was such that 1% to 2% of the beam was lost in this region. There was an appreciable amount of beam extracted as shown in Table 1, which gives the yearly integrated intensities from 1973 to 1997. A simple model of the extraction losses was set up by Chandra Bhat utilizing the program CASIM. A sample output I shown in figure 1 which gives contours of stars/cm3 in the dirt, also schematically depicted are the three six feet deep sampling holes which were drilled to map out this cascade. One aspect of this study has been the study of the production of non-migrating nuclides and further study may in fact yield better values for the K parameter, the probability per star that an atom of the particular nuclide will be produced. Also the results of this study can give experimental numbers for the production of other nuclides when the amount of Na22 has been calculated. However, the most important part of this study has been the determination of the amount of tritium produced by extraction from the Booster and the experimentally determined migration rate. If we look at the top sample result in hole S2 of 777 pCi/ml of tritium and use the experimentally determined rate of migration and the depth to the aquifer of 13.1m, they calculate that the concentration will have decayed away to 1.1E-8 pCi/ml. If we look at the bottom sample, which is 11.3 m away from the aquifer, they calculate that the 116 pCi/ml will have decayed to 5.2E-8 pCi/ml. The conclusions is that the rate of migration determined over the 24 year irradiation history of the Booster extraction point is small enough that there is no problem with migration of tritium to the aquifer.

  11. Study of the recrystallisation of irradiated uranium

    Bloch, J.; Mustelier, J.P.; Bussy, P.; Blin, J.

    1958-01-01

    1- Study of the recrystallisation of irradiated uranium. The recrystallisation of uranium irradiated to a burnup level of 220 MWj/t, at a temperature of the order of 350 deg. C, has been investigated. The observations were made chiefly by means of micrography an hardness measurements. If the irradiated metal is compared with a cold-drawn metal showing the same shearing of the twinned crystals, and therefore the same rate of plastic deformation, as the irradiated metal, it is noted that the restoring of the irradiated metal takes place at a considerably higher temperature than that of the cold-drawn metal. Pre-crystallisation is very much delayed. Only, a passage of the α-β transformation point quickly wipes out irradiation effect. 2- Hardening of uranium by irradiation. Using hardness measurements we have studied more especially the effect of very weak irradiations on uranium (integrated flux 16 nvt). The hardness does not increase linearly with the flux, but a period of incubation is observed probably representing the time necessary for saturation of the dislocations. (author) [fr

  12. Evaluation of broadband surface solar irradiance derived from the Ozone Monitoring Instrument

    Wang, P.; Sneep, M.; Veefkind, J.P.; Stammes, P.; Levelt, P.F.

    2014-01-01

    Surface solar irradiance (SSI) data are important for planning and estimating the production of solar power plants. Long-term high quality surface solar radiation data are needed for monitoring climate change. This paper presents a new surface solar irradiance dataset, the broadband (0.2–4 ?m)

  13. Some wholesomeness studies on irradiated Iraqi dates

    Al Rawi, A.M.; Hamoudi, H.I.

    1981-01-01

    Iraqi dates (Zahdi and Khestawi) were irradiated at different dose levels (0 to 1500 krad) to extend their shelf-lives. Samples irradiated at 150 krad showed no change in the behaviour studies of tested Swiss albino mice. Fungi were found to have a constant rate of growth on the syrup irradiated dates. Chemical products such as malondialdehyde, deoxy sugars, acids and reducing sugars were quantified. In conclusion, 150 krad is a convenient dose to extend the shelf-lives of the tested dates and is therefore recommended. (author)

  14. Irradiation preservation processing study of strawberry

    Xu Shihong; Zhu Zhaodi

    1992-01-01

    Radiation preservation processing of strawberry was studied. The results show that single seal processing or combining with irradiation processing under given doses is of no practical value, but only combining with chill processing can promote lengthening period of fresh keeping. Single irradiation processing under given doses provides not only good initial state, but also the beginning of bad development at top speed on microorganism. The composite processing of irradiation, chill and seal can supply extended shelf lifetime with optimum value of dual synergetic effect

  15. Monitoring free radicals in γ-irradiated food

    Hunter, C.R.; Hutton, D.R.

    1988-01-01

    Irradiation of various food products, including vegetables, fruits, meats, seafoods, herbs, spices and seeds by appropriate doses by γ rays has for many years been suggested as a means of killing bacteria, viruses and pests and so preserving the foods. The position of food irradiation is under review in Australia through consumer organisations (Australian Consumers Association 1987) and by a current Federal Government inquiry. From these reviews and inquiries recommendations for irradiation, packaging, etc., are emerging, with for example, recommended maximum dose of 10 kGy for Australia, with 6 kGy being a minimum dose for grains and spices

  16. Thermoluminescent and impedimetric studies on irradiated foodstuffs

    Mamoon, A.M.

    2000-01-01

    Several brands of different spices and milk powders were irradiated with relatively high doses of gamma radiation. Glow curves were produced upon heating these irradiated foodstuffs only. Study of the obtained spices glow curves revealed that the magnitude of these curves depends upon the dose received while the shape of the curves remains generally the same for the different doses and for the different spices. Previous studies had shown that the obtained thermoluminescence (TL) is due to dust particles carried by the spices. The TL studies show, furthermore, that different brands of the same spice are apparently contaminated with different amounts of dust or soil. The obtained TL from irradiated milk powders is apparently due to its mineral content. Different milk powders gave TL curves of different magnitudes for the same dose depending upon the milk brand. Impedimetric studies carried out irradiated potatoes show changes in impedance amplitude and phase angle. The results support earlier work on the use of TL to differentiate between irradiated and control foodstuffs, to assess the extent of spices contamination with soil-which perhaps reflects hygienic care-and that impedimetric measurements can distinguish irradiated from control potatoes

  17. Development of absolute intensity monitors and homogeneous irradiation system for synchrotron radiation at SPring-8

    Nariyama, N.; Taniguchi, S.; Kishi, N.; Ohnishi, S.; Odano, N.

    2003-01-01

    At SPring-8 of 8-GeV synchrotron radiation facility in Japan, high-intense monoenergetic photon beam up to hundred keV are available. For biological and medical researches, the absolute intensity monitor and homogeneous irradiation system are necessary. In this study, as intensity monitor two sizes of parallel-plate free-air ionization chambers were developed: plate distance of 8.5 cm for high-energy photons up to 190 keV and that of 0.42 cm for low-energy high-intense photons from undulator. Sizes of the larger chamber were determined considering electron loss using a Monte Carlo electron-photon transport code EGS4. For homogeneous irradiation method, a rotational linear-scanning method was proposed. An experiment was carried out at bending-magnet beamlines BL20B2 and 38B1 for high-energy photons. Dose measured with the chamber was compared to that of another free-air ionization chamber with 5-cm plate separation and a Si-PIN photodiode, which have been calibrated with a calorimeter. Agreement was confirmed from 30 keV up to 150 keV with a discrepancy less than 3%, which were independent of the beam size, intensity and injection position of the chamber. For intense photons from undulator, saturation measurement was made using the smaller chamber at BL46XU. Saturation was confirmed at 3 kV for 15- and 20-keV photons up to 10 12 photons/s. Using the larger chamber, fixed and Xθ -scanning irradiation methods were compared by irradiating thermoluminescent dosimeters at BL20B2, which can provide broad beam. As a function of the estimated exposure, all the signal data points became on the same straight line. Consequently, the Xθ -scanning method was found to be effective

  18. Heavy ions amorphous semiconductors irradiation study

    Benmalek, M.

    1978-01-01

    The behavior of amorphous semiconductors (germanium and germanium and arsenic tellurides) under ion bombardment at energies up to 2 MeV was studied. The irradiation induced modifications were followed using electrical parameter changes (resistivity and activation energy) and by means of the transmission electron microscopy observations. The electrical conductivity enhancement of the irradiated samples was interpreted using the late conduction theories in amorphous compounds. In amorphous germanium, Electron Microscopy showed the formations of 'globules', these defects are similar to voids observed in irradiated metals. The displacement cascade theory was used for the interpretation of the irradiation induced defects formation and a coalescence mechanism of growth was pointed out for the vacancy agglomeration [fr

  19. Feeding Studies of Irradiated Foods with Insects

    Loaharanu, Srisan

    1978-06-15

    Insects are of value to man in many scientific studies. Microsomal detoxication systems exist in both insects and mammals. In the preliminary investigations it was found that irradiated cocoa beans and white and red kidney beans (Phaseolus spp.) did not significantly change the percentage of egg-hatch in the insects tested. In more detailed investigations food samples that are susceptible to insect spoilage and are representatives of widely consumed human foods were fed to various insect species. The development, sex distortion and reproductivity of the insects were investigated. Cytogenetic aberrations as related to dominant lethality were studied in insects with reasonably clear chromosomal patterns. The meiosis stage was examined, using the squash technique and Aceto-orcein staining. Black beans, Phaseolus spp., irradiated with up to 200 krad of gamma rays did not apparently change the percentage of survival and the sex ratio of the bean weevil, Zabrotes subfasciatus. Dominant lethality in the German cockroach, Blatella germanica, fed on irradiated black beans did not apparently occur when considering the results of cytological investigation and the number of offspring obtained. Dried sardine samples irradiated with up to 400 krad of gamma rays neither apparently affected the survival nor caused sex distortion in the cheese skipper, Piophila casei. This irradiated product apparently did not induce dominant lethality in the German cockroach as tested. Coffee processed from coffee beans that had been irradiated with up to 100 krad of gamma rays did not apparently cause adverse effects on the experimental insects. (author)

  20. Feeding studies of irradiated foods with insects

    Loaharanu, S.

    1978-01-01

    Insects are of value to man in many scientific studies. Microsomal detoxication systems exist in both insects and mammals. In the preliminary investigations it was found that irradiated cocoa beans and white and red kidney beans (Phaseolus spp.) did not significantly change the percentage of egg-hatch in the insects tested. In more detailed investigations food samples that are susceptible to insect spoilage and are representatives of widely consumed human foods were fed to various insect species. The development, sex distortion and reproductivity of the insects were investigated. Cytogenetic aberrations as related to dominant lethality were studied in insects with reasonably clear chromosomal patterns. The meiosis stage was examined, using the squash technique and Aceto-orcein staining. Black beans, Phaseolus spp., irradiated with up to 200 krad of gamma rays did not apparently change the percentage of survival and the sex ratio of the bean weevil, Zabrotes subfasciatus. Dominant lethality in the German cockroach, Blatella germanica, fed on irradiated black beans did not apparently occur when considering the results of cytological investigation and the number of offspring obtained. Dried sardine samples irradiated with up to 400 krad of gamma rays neither apparently affected the survival nor caused sex distortion in the cheese skipper, Piophila casei. This irradiated product apparently did not induce dominant lethality in the German cockroach as tested. Coffee processed from coffee beans that had been irradiated with up to 100 krad of gamma rays did not apparently cause adverse effects on the experimental insects. (author)

  1. Investigation of neutron fluence using fluence monitors for irradiation test at WWR-K

    Romanova, N.K.; Takemoto, N.

    2013-01-01

    Irradiation test of a Si ingot is planned using WWR-K in Institute of Nuclear Physics Republic of Kazakhstan (INP RK) to develop an irradiation technology for Si semiconductor production by Neutron Transmutation Doping (NTD) method in the framework of an international cooperation between INP RK and Japan Atomic Energy Agency (JAEA), Japan. It is possible to irradiate the Si ingot of 6 inch in diameter at the K-23 irradiation channel in the WWR-K. The preliminary irradiation test using 4 Al ingots was performed to evaluate the actual neutronic irradiation field at the K-23 channel in the WWR-K. Each Al ingot has the same dimension as the Si ingot, and 15 fluence monitors are equipped in it. Iron wire and aluminum-cobalt wire are inserted into them, and it is possible to evaluate both fast and thermal neutron fluxes by measurement of these radiation activities after irradiation. This report described the results of the preliminary irradiation test and the neutronic calculations by Monte Carlo method in order to evaluate the neutronic irradiation field in the irradiation position for the silicon ingot at the channel in the WWR-K. (authors)

  2. Wide area monitoring study

    Wogman, N.A.; Holdren, G.R. Jr.

    1999-01-01

    Environmental sampling can be used to complement the safeguarding of nuclear material, especially in the detection of undeclared nuclear activities. Routine monitoring of nuclear installations has provided valuable information about the fate of key signature materials within different environmental settings. The approach collates information regarding the generation of individual radiochemical signatures within different nuclear processes, the potential for release of these signatures to the environment and, the chemical form and mobility of the signatures in environmental media along which the material could migrate. Meteorological, geological and hydrological information is used to determine where to sample, what to sample, and how often to sample to provide the greatest likelihood for detection. Multiple strategies can be used to implement wide area monitoring for safeguards purposes. The most complex, and expensive of these, involves establishing extensive networks of fixed location sampling sites. The sites would be operated continuously, and would be instrumented with automated sampling, analysis, and communication equipment to relay information regarding potential anomalies to control centers in near-real time. Alternative strategies can be used to supplement fixed location monitoring equipment, especially in regions that cannot support (financially or logistically) the fixed stations. Through combinations of these various strategies, using a variety of environmental media to monitor a region, we believe that a competent network, one with a quantifiable probability for detecting undeclared nuclear activities, can be designed. While this approach cannot and should not replace other inspection and monitoring activities, it can potentially contribute valuable information to an international safeguards system. (author)

  3. Electron microscope study of irradiated beryllium oxide

    Bisson, A.A.

    1965-06-01

    The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. α) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10 19 , 9 x 10 19 and 2 x 10 20 n f cm -2 at a temperature below 100 deg. C. For the irradiation at 6 x 10 19 n f cm -2 , the defects are merely visible, but at 2 x l0 20 n f cm -2 the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [fr

  4. Monitoring of gluconeogenesis in rats following chronic irradiation

    Paulikova, E.; Sedlakova, A.; Praslicka, M.

    1984-01-01

    A dose dependent cumulation of liver glycogen with the maximum on the day 120 was observed as was an increased incorporation of 14 C-alanine in liver glycogen (statistically nonsignificant changes). The contribution of 14 C-acetate to gluconeogenesis was negligible. The results showed increased gluconeogenesis in rats following chronic gamma irradiation with small daily dose rates (0.0957 Gy)

  5. Genetic monitoring of irradiated Drosophila populations treated with antimutagen melanine

    Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

    1986-01-01

    It was shown that viability of irradiated Drosophila is, on an average, lower than in intact populations. The fertility first decreases then increases exceeding the control level. Melanine added to the diet increases fertility and viability of both exposed and intact Drosophila populations

  6. Spectroscopic study of gamma irradiated bovine hemoglobin

    Maghraby, Ahmed Mohamed; Ali, Maha Anwar

    2007-01-01

    In the present study, the effects of ionizing radiation of Cs-137 and Co-60 from 4.95 to 743.14 Gy and from 40 Gy to 300 kGy, respectively, on some bovine hemoglobin characteristics were studied. Such an effect was evaluated using electron paramagnetic resonance (EPR) spectroscopy, and infra-red (IR) spectroscopy. Bovine hemoglobin EPR spectra were recorded and analyzed before and after irradiation and changes were explained in detail. IR spectra of unirradiated and irradiated Bovine hemoglobin were recorded and analyzed also. It was found that ionizing radiation may lead to the increase of free radicals production, the decrease in α-helices contents, which reflects the degradation of hemoglobin molecular structure, or at least its incomplete performance. Results also show that the combined application of EPR and FTIR spectroscopy is a powerful tool for determining structural modification of bovine hemoglobin samples exposed to gamma irradiation

  7. Facts about food irradiation: Genetic studies

    1991-01-01

    Results published in the mid-1970s from the National Institute of Nutrition (NIN) in India showed increased numbers of polyploid cells in rats, mice, monkeys and malnourished children fed irradiated wheat products. This fact sheet considers the validity of these results. A large number of independent studies have been subsequently performed, and in none of these have results been obtained that support the NIN findings. The conclusion is that there is no evidence to link the consumption of irradiated food with any mutagenic effect. 3 refs

  8. Monitoring of gluconeogenesis in rats following chronic irradiation

    Paulikova, E.; Sedlakova, A.; Praslicka, M. (Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie)

    1984-01-01

    A dose dependent cumulation of liver glycogen with the maximum on the day 120 was observed as was an increased incorporation of /sup 14/C-alanine in liver glycogen (statistically nonsignificant changes). The contribution of /sup 14/C-acetate to gluconeogenesis was negligible. The results showed increased gluconeogenesis in rats following chronic gamma irradiation with small daily dose rates (0.0957 Gy).

  9. Studies on some irradiated food products

    Mohammed, H.M.B.

    1998-01-01

    The aim of this investigation was to study the possibility of using some doses of gamma irradiation and cold storage (4+1 C) for improving the hygienic quality and shelf-life of some meat products ( beef luncheon, processed minced beef and fresh beef sausage). luncheon meat samples were irradiated at doses of 4,6,8,10 and 12 k Gy, while beef and sausage samples were subjected to 4,6 and 8 KGy gamma rays doses and the effects of irradiation on the organoleptic properties, microbiological aspects and the chemical composition were studied during cold storage (4+1 C) of samples. Attention was focussed on the changes occurred in the organoleptic properties of these products by the evaluation of sensory scores for appearance, color and odor of samples post irradiation and during cold storage (4+1 C). In addition, the effects of treatments and cold storage on the microbiological quality by the determination of total bacterial count, total psychropilic bacteria, total coliforms, total molds and yeasts, staphylococcus aureus, streptococcus faecalis as well as the detection of salmonellae were studied

  10. Monte Carlo studies for irradiation process planning at the Portuguese gamma irradiation facility

    Oliveira, C.; Salgado, J.; Botelho, M.L.M. Luisa; Ferreira, L.M.

    2000-01-01

    The paper describes a Monte Carlo study for planning the irradiation of test samples for microbiological validation of distinct products in the Portuguese Gamma Irradiation Facility. Three different irradiation geometries have been used. Simulated and experimental results are compared and good agreement is observed. It is shown that Monte Carlo simulation improves process understanding, predicts absorbed dose distributions and calculates dose uniformity in different products. Based on these results, irradiation planning of the product can be performed

  11. Monitoring of releases from an irradiated fuel reprocessing plant

    Fitoussi, L.

    1978-01-01

    At its UP 2 plant, the La Hague facility reprocesses irradiated fuel by the PUREX process. The fuel stems from graphite/gas, natural-uranium reactors and pressurized or boiling water enriched-uranium reactors. The gaseous effluents are collected and purified by high-efficiency washing and filtration. After purification the gas stream is discharged into the atmosphere by a single stack, 100m high and 6m in diameter, located at a high point on the site (184m). The radionuclides released into the air are: krypton-85, iodine-129 and -131, and tritium. The liquid effluents are collected by drainage systems, which transfer them to the effluent treatment station in the case of active or suspect solutions. Active solutions undergo treatment by chemical and physical processes. After purification the waste water is released into the sea by an underwater drainage system 5km long, which brings the outlet point into the middle of a tidal current 2km offshore. The radionuclides contained in the purified waste water are fission products originating from irradiated fuels in only slightly variable proportions, in which ruthenium-rhodium-106 predominates. Traces of the transuranium elements are also found in these solutions

  12. Consumer acceptance of irradiated food products: an apple marketing study

    Terry, D.E.; Tabor, R.L.

    1990-01-01

    This study was exploratory in nature, with emphasis on initial purchases and not repeat purchases or long-term loyalties to either irradiated or non-irradiated produce. The investigation involved the actual sale of irradiated and non-irradiated apples to consumers. Limited information about the process was provided, and apples were sold at roadside stands. Prices for the irradiated apples were varied while the price for the non-irradiated apples was held constant. Of these 228 West-Central Missouri shoppers, 101 (44%) bought no irradiated apples, 86 (38%) bought only irradiated apples, and 41 (18%) bought some of both types, Results of probit regressions indicated three significant independent variables. There was an inverse relationship between the price of irradiated apples and the probability of purchasing irradiated apples. There was a positive relationship between the purchasers’ educational level and the probability of purchasing irradiated apples. Predicted probabilities for belonging to categories in probit models were computed. Depending on particular equation specification, correctly placed were approximately 70 percent of the purchasers of the two categories--bought only non-irradiated apples, or bought some of both irradiated and non-irradiated apples or only irradiated apples. This study suggests that consumers may be interested in food irradiation as a possible alternative or supplement to current preservation techniques

  13. Cytologic studies on irradiated gestric cancer cells

    Isono, S; Takeda, T; Amakasu, H; Asakawa, H; Yamada, S [Miyagi Prefectural Adult Disease Center, Natori (Japan)

    1981-06-01

    The smears of the biopsy and resected specimens obtained from 74 cases of irradiated gastric cancer were cytologically analyzed for effects of irradiation. Irradiation increased the amount of both necrotic materials and neutrophils in the smears. Cancer cells were decreased in number almost in inverse proportion to irradiation dose. Clusters of cancer cells shrank in size and cells were less stratified after irradiation. Irradiated cytoplasms were swollen, vacuolated and stained abnormally. Irradiation with less than 3,000 rads gave rise to swelling of cytoplasms in almost all cases. Nuclei became enlarged, multiple, pyknotic and/or stained pale after irradiation. Nuclear swelling was more remarkable in cancer cells of differentiated adenocarcinomas.

  14. Study of inhibition on lipid oxidation of irradiated pork

    Ha Yiming

    2006-03-01

    It was studied that the effect factors of irradiation dose, preservation temperature, oxygen content and antioxidant on lipid oxidation of irradiated pork. A mechanism was explained on lipid oxidation of irradiated pork. The results showed that irradiation might aggravate lipid oxidation of pork and that decreased preservation temperature and oxygen content of the packaging, added antioxidant also could effectively inhibit lipid oxidation of irradiated pork. (authors)

  15. Optical fiber sensor for low dose gamma irradiation monitoring

    de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

    2016-05-01

    An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

  16. Study on irradiation treatment to drunk crab

    Cao Hong; Chen Xiulan; Zhai Jianqing; Bao Jianzhong; Wang Jinrong

    2002-01-01

    For guaranteeing the quality of irradiated drunk crab, manufacture method of the dosimeter, sample setting and taking position, irradiation time, asymmetry degree of irradiation dose, contrast of the dosimeter are discussed and some reference datum to commercialization of drunk crab's irradiation are provided

  17. Effects of synchronous irradiance monitoring and correction of current-voltage curves on the outdoor performance measurements of photovoltaic modules

    Hishikawa, Yoshihiro; Doi, Takuya; Higa, Michiya; Ohshima, Hironori; Takenouchi, Takakazu; Yamagoe, Kengo

    2017-08-01

    Precise outdoor measurement of the current-voltage (I-V) curves of photovoltaic (PV) modules is desired for many applications such as low-cost onsite performance measurement, monitoring, and diagnosis. Conventional outdoor measurement technologies have a problem in that their precision is low when the solar irradiance is unstable, hence, limiting the opportunity of precise measurement only on clear sunny days. The purpose of this study is to investigate an outdoor measurement procedure, that can improve both the measurement opportunity and precision. Fast I-V curve measurements within 0.2 s and synchronous measurement of irradiance using a PV module irradiance sensor very effectively improved the precision. A small standard deviation (σ) of the module’s maximum output power (P max) in the range of 0.7-0.9% is demonstrated, based on the basis of a 6 month experiment, that mainly includes partly sunny days and cloudy days, during which the solar irradiance is unstable. The σ was further improved to 0.3-0.5% by correcting the curves for the small variation of irradiance. This indicates that the procedure of this study enables much more reproducible I-V curve measurements than a conventional usual procedure under various climatic conditions. Factors that affect measurement results are discussed, to further improve the precision.

  18. Monitoring of the Irradiated Neutron Fluence in the Neutron Transmutation Doping Process of Hanaro

    Kim, Myong-Seop; Park, Sang-Jun

    2009-08-01

    Neutron transmutation doping (NTD) for silicon is a process of the creation of phosphorus impurities in intrinsic or extrinsic silicon by neutron irradiation to obtain silicon semiconductors with extremely uniform dopant distribution. HANARO has two vertical holes for the NTD, and the irradiation for 5 and 6 inch silicon ingots has been going on at one hole. In order to achieve the accurate neutron fluence corresponding to the target resistivity, the real time neutron flux is monitored by self-powered neutron detectors. After irradiation, the total irradiation fluence is confirmed by measuring the absolute activity of activation detectors. In this work, a neutron fluence monitoring method using zirconium foils with the mass of 10 ~ 50 mg was applied to the NTD process of HANARO. We determined the proportional constant of the relationship between the resistivity of the irradiated silicon and the neutron fluence determined by using zirconium foils. The determined constant for the initially n-type silicon was 3.126 × 1019 n·Ω/cm. It was confirmed that the difference between this empirical value and the theoretical one was only 0.5%. Conclusively, the practical methodology to perform the neutron transmutation doping of silicon was established.

  19. Studies on preservation of agricultural products by irradiation

    Chung, K.H.; Kwon, S.H.; Lee, Y.I.; Chae, J.C.; Shin, I.C.

    1981-01-01

    This study was attempted to develop and establish the preservation techniques of agricultural products by irradiation through ascertainment of the optimum irradiation doses for sprout inhibition of white potato and chestnut, and for disinfestation of rice insects during storage

  20. Studies on potato irradiation in the G.D.R

    Luther, Th.; Huebner, G.; Grahn, Ch.; Doellstaedt, R.

    1990-01-01

    The studies of potato irradiation have been conducted in the framework of the National Food Irradiation Research Project for 4 years. Although in the G.D.R. the use of chemical sprout inhibitors is allowed, potato irradiation can be an alternative technique for potato processing. Before irradiation a wound healing period of approx. 2 weeks is absolutely necessary to protect the potatoes from Fusarium. The method that presents the minimum risk of damage is irradiation in containers. Economic evaluations for the irradiation of potatoes are also made. (author)

  1. Infrared irradiation of skin for the development of non-invasive health monitoring technologies

    Abdussamad Abbas, Hisham; Triplett, Gregory

    2015-06-01

    Infrared radiation was employed to study the optical transmission properties of pigskin and the factors that influence transmission at room temperature. The skin samples from the forehead of piglets were irradiated using an infrared-pulsed source by varying the beam properties such as optical power, power density, duty cycle, as well as sample thickness. Because infrared radiation in select instances can penetrate through thick-fleshy skin more easily than visible radiation, temperature fluctuations observed within the skin samples stemming from exposure-dependent absorption revealed interesting transmission properties and the limits of optical exposure. Pigskin was selected for this study since its structure most closely resembles that of human skin. Furthermore, the pulsed beam technique compared to continuous operation offers more precise control of heat generation within the skin. Through this effort, the correlated pulsed-beam parameters that influence infrared transmission were identified and varied to minimize the internal absorption losses through the dermis layers. The two most significant parameters that reduce absorption losses were frequency and duty cycle of the pulsed beam. Using the Bouger-Beer-Lambert Law, the absorption coefficient from empirical data is approximated, while accepting that the absorption coefficient is neither uniform nor linear. Given that the optical source used in this study was single mode, the infrared spectra obtained from irradiated samples also reveal characteristics of the skin structure. Realization of appropriate sample conditions and exposure parameters that reduce light attenuation within the skin and sample degradation could give way to novel non-invasive measuring techniques for health monitoring purposes.

  2. Infrared absorption studies of the annealing of irradiated diamonds

    Woods, G.S.

    1984-01-01

    Natural (types Ia and IIa) and synthetic (type Ib) diamonds have been irradiated with energetic electrons and neutrons and then heated at temperatures up to 1400 deg C. Attendant changes in the infrared absorption spectra, especially above the Raman frequency (1332 cm -1 ), have been monitored. The most prominent absorption to develop in the infrared region proper, on annealing both type Ia and type Ib specimens, whether electron- or neutron-irradiated is the H1a line at 1450 cm -1 . Measurements taken of neutron-irradiated type Ia specimens show that the strength of this line is specimen-dependent, and that it is a linear function of radiation dose. Isochronal annealing studies show that the onset of the line occurs during heating at 250 deg C for type Ia specimens and at 650 deg C for type Ib specimens. The absorption begins to weaken during heating at 1100 deg C, but it is very persistent, surviving an anneal of 4 hours at 1400 deg C, albeit with diminished intensity. Three other weaker lines at 1438, 1358 and 1355 cm -1 develop with the 1450 cm -1 line, but differ from it and from each other in subsequent annealing behaviour. Other lines were observed; these are reported and discussed. (author)

  3. Study of irradiation induced defects in silicon

    Pal, Gayatri; Sebastian, K.C.; Somayajulu, D.R.S.; Chintalapudi, S.N.

    2000-01-01

    Pure high resistivity (6000 ohm-cm) silicon wafers were recoil implanted with 1.8 MeV 111 In ions. As-irradiated wafers showed a 13 MHz quadrupole interaction frequency, which was not observed earlier. The annealing behaviour of these defects in the implanted wafers was studied between room temperature and 1073 K. At different annealing temperatures two more interaction frequencies corresponding to defect complexes D2 and D3 are observed. Even though the experimental conditions were different, these are identical to the earlier reported ones. Based on an empirical point charge model calculation, an attempt is made to identify the configuration of these defect complexes. (author)

  4. Preliminary study on sterilization effect of irradiation on dry vegetable

    Zhai Jianqing; Bao Jianzhong; Cao Hong; Wang Jinrong; Chen Xiulan

    2004-01-01

    The number of surviving germs relationship to irradiation dose for several species dry vegetable was studied, and the original value D 10 of the dry vegetable was given. The value will provide a theoretical reference to ascertain the appropriate irradiation dose in the irradiation process of the dry vegetable

  5. XRD monitoring of α self-irradiation in uranium-americium mixed oxides.

    Horlait, Denis; Lebreton, Florent; Roussel, Pascal; Delahaye, Thibaud

    2013-12-16

    The structural evolution under (241)Am self-irradiation of U(1-x)Am(x)O(2±δ) transmutation fuels (with x ≤ 0.5) was studied by X-ray diffraction (XRD). Samples first underwent a preliminary heat treatment performed under a reducing atmosphere (Ar/H2(4%)) aiming to recover the previously accumulated structural defects. Over all measurements (carried out over up to a full year and for integrated doses up to 1.5 × 10(18) α-decay events·g(-1)), only fluorite U(1-x)Am(x)O(2±δ) solid solutions were observed. Within a few days after the end of the heat treatment, each of the five studied samples was slowly oxidized as a consequence of their move to air atmosphere, which is evidenced by XRD by an initial sharp decrease of the unit cell parameter. For the compounds with x ≤ 0.15, this oxidation occurred without any phase transitions, but for U0.6Am0.4O(2±δ) and U0.5Am0.5O(2±δ), this process is accompanied by a transition from a first fluorite solid solution to a second oxidized one, as the latter is thermodynamically stable in ambient conditions. In the meantime and after the oxidation process, (241)Am α self-irradiation caused a structural swelling up to ∼0.8 vol %, independently of the sample composition. The kinetic constants of swelling were also determined by regression of experimental data and are, as expected, dependent on x and thus on the dose rate. The normalization of these kinetic constants by sample α-activity, however, leads to very close swelling rates among the samples. Finally, evolutions of microstrain and crystallite size were also monitored, but for the considered dose rates and cumulated doses, α self-irradiation was found, within the limits of the diffractometer used, to have almost no impact on these characteristics. Microstrain was found to be influenced instead by the americium content in the materials (i.e., by the impurities associated with americium starting material and the increase of cationic charge heterogeneity with

  6. Monitoring longitudinal changes in irradiated head and neck cancer xenografts using diffuse reflectance spectroscopy

    Vishwanath, Karthik; Jiang, Shudong; Gunn, Jason R.; Marra, Kayla; Andreozzi, Jacqueline M.; Pogue, Brian W.

    2016-02-01

    Radiation therapy is often used as the preferred clinical treatment for control of localized head and neck cancer. However, during the course of treatment (6-8 weeks), feedback about functional and/or physiological changes within impacted tissue are not obtained, given the onerous financial and/or logistical burdens of scheduling MRI, PET or CT scans. Diffuse optical sensing is well suited to address this problem since the instrumentation can be made low-cost and portable while still being able to non-invasively provide information about vascular oxygenation in vivo. Here we report results from studies that employed an optical fiber-based portable diffuse reflectance spectroscopy (DRS) system to longitudinally monitor changes in tumor vasculature within two head and neck cancer cell lines (SCC-15 and FaDu) xenografted in the flanks of nude mice, in two separate experiments. Once the tumor volumes were 100mm3, 67% of animals received localized (electron beam) radiation therapy in five fractions (8Gy/day, for 5 days) while 33% of the animals served as controls. DRS measurements were obtained from each animal on each day of treatment and then for two weeks post-treatment. Reflectance spectra were parametrized to extract total hemoglobin concentration and blood oxygen-saturation and the resulting time-trends of optical parameters appear to be dissimilar for the two cell-lines. These findings are also compared to previous animal experiments (using the FaDu line) that were irradiated using a photon beam radiotherapy protocol. These results and implications for the use of fiber-based DRS measurements made at local (irradiated) tumor site as a basis for identifying early radiotherapy-response are presented and discussed.

  7. Absolute, Extreme-Ultraviolet Solar Spectral Irradiance Monitor (AESSIM)

    1994-04-01

    molecular constituents [Meier 1991]. This radiation is the principal source of energy for producing and maintaining the complex, time-dependent, thermal...158.4 nm emisions for interstellar wind studies. After -2005, there is unlikely to be sufficient power to provide the requisite heating of the scan

  8. Assessment of necessary regularity of internal irradiation monitoring on the basis of direct and indirect methods of dosimetry

    Malykhin, V.M.; Ivanova, N.I.

    1981-01-01

    It is shown that when assessing the necessary periodicity of internal irradiation monitoring, it is required to take account of the nature (rhythm) of radionuclide intake to the organism during the monitoring period, the effective period of radionuclide biological half-life, its activity in the organism, sensitivity of the technique applied and the labour-consumig character of the monitoring method [ru

  9. Integrated studies on irradiated Philippine mangoes

    Manalo, J.A.; Legaspi, E.; Quarteros, R.; Grimares, L.; Escano, L.; Marzan, A.; Lanuza, A.; Singson, C.C.

    1990-01-01

    The presence of the fruitfly, Dacus dorsalis Hendel, has restricted export of Philippine mangoes to Japan and other countries with strict quarantine requirements. The anticipated banning of the ethylene dibromide (EDB) as fumigant necessitated studies to find a suitable replacement. Based on the encouraging results of previous disinfestation experiments further studies utilizing irradiation and its combination with a hot water dip were undertaken. The objective of the studies was to interrelate the effects of the disinfestation method to fruit maturity, storage temperature, and some related processes, including shipping, on the shelf-life, chemical, and sensory attributes of the carabao mango. Results show that the combination treatment of 0.65 kGy and a hot water dip at 50 deg. C for 5 minutes can be a good alternative for ethylene dibromide with the added benefit of shelf life extension. The chemical, nutritive and sensory characteristics of the fruit also are retained. 32 refs, 19 tabs

  10. Studies of defects on ion irradiated diamond

    Lai, P F; Prawer, S; Spargo, A E.C.; Bursill, L A [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  11. Studies of defects on ion irradiated diamond

    Lai, P.F.; Prawer, S.; Spargo, A.E.C.; Bursill, L.A. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    It is known that diamond is amorphized or graphitized when irradiated above a critical dose. Above this critical dose, D{sub c}, the resistance R is found to drop very rapidly due to the formation of graphite regions which overlap at D{sub c} to form a semi-continuous electrically conducting pathway through the sample. One particularly interesting method of studying this transformation is electron energy-loss spectroscopy (EELS). Using EELS, the different phases of carbon can be identified and distinguished from each other using the extended energy-loss fine structure (EXELFS) of the core-loss part of the spectrum. EELS is a sensitive method for determining the electronic structure of small areas of a sample. In this paper, transmission electron microscopy (TEM) and EELS measurements of the ion irradiated diamond were combined in an attempt to correlate the microstructural nature of the ion-beam induced damage to the changes in the electrical and other properties. 7 refs., 1 tab., 2 figs.

  12. An ESR study of radicals induced in irradiated fresh mango

    Kikuchi, Masahiro; Hussain, Mohammed S.; Morishita, Norio; Kobayashi, Yasuhiko; Ukai, Mitsuko; Shimoyama, Yuhei

    2009-01-01

    An electron spin resonance (ESR) spectroscopic study was performed on the radicals induced irradiated fresh mangoes. Fresh Philippine mangoes were irradiated by the γ-rays, lyophilized and powdered. The ESR spectrum of the dry specimen showed a strong main peak at g=2.004 and a pair of peaks at both magnetic fields of the main peak. The main peak detected from flesh and skin specimens faded away in a few days after the irradiation. On the other hand, the side peaks showed a well-defined dose response even 9 days after the irradiation. The side-peak is a useful mean to define the irradiation on fresh mangoes. (author)

  13. Biochemical and Tissue Studies on Post Irradiation Recovery in Mammals

    Abdou, M.I.M.

    2004-01-01

    three main studies were performed in this thesis, namely, mortality and survival study, biochemical studies, and studies on tissue alterations cobalt-60 gamma irradiation for low let was used for the external whole body irradiation of the irradiated animal groups. a total number of animals of 722 virgin female adult wister rats of approximately the same age and weight were used for the three studies that were performed, including the control and irradiated animal groups. the animals were housed and kept with special care at fixed temperature, humidity and diet. the study on mortality and survival included 370 animals divided into control and groups irradiated with 4,5,6,7,8 and 9 Gy. this study was followed up for one year to record the number and date of animal deaths for the different irradiated groups. for the 8 and 9 Gy irradiated groups the follow up ended after 12 weeks and 11 days respectively when animal mortality reached 100%. the maximum percent mortality was noted at the second week (3.3,8,14 and 29%) for the 4,5,6 and 7 Gy irradiated groups respectively. for the 8 and 9 Gy irradiated groups, the maximum percent mortality was noted at the first week (42.9 and 90% respectively). regression equations were applied for the percent of mortality of the 5-8 Gy irradiated groups to estimate the LD 50/30, which was found to be 6.4 Gy

  14. Study of the recrystallisation of irradiated uranium; Etude sur l'uranium irradie

    Bloch, J; Mustelier, J P; Bussy, P; Blin, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    1- Study of the recrystallisation of irradiated uranium. The recrystallisation of uranium irradiated to a burnup level of 220 MWj/t, at a temperature of the order of 350 deg. C, has been investigated. The observations were made chiefly by means of micrography an hardness measurements. If the irradiated metal is compared with a cold-drawn metal showing the same shearing of the twinned crystals, and therefore the same rate of plastic deformation, as the irradiated metal, it is noted that the restoring of the irradiated metal takes place at a considerably higher temperature than that of the cold-drawn metal. Pre-crystallisation is very much delayed. Only, a passage of the {alpha}-{beta} transformation point quickly wipes out irradiation effect. 2- Hardening of uranium by irradiation. Using hardness measurements we have studied more especially the effect of very weak irradiations on uranium (integrated flux < 10{sup 16} nvt). The hardness does not increase linearly with the flux, but a period of incubation is observed probably representing the time necessary for saturation of the dislocations. (author)Fren. [French] 1- Etude de la recristallisation de l'uranium irradie. On a etudie la recristallisation d'uranium irradie jusqu'a un taux de combustion de 220 MWj/t a une temperature de l'ordre de 350 deg. C. Les observations ont ete faites principalement a l'aide de la micrographie et de la durete. Si l'on compare le metal irradie avec un metal ecroui presentant le meme cisaillement des macles, donc le meme taux de deformation plastique que le metal irradie, on constate que la restauration du metal irradie se fait a une temperature notablement superieure a celle du metal ecroui. La recristallisation est tres retardee. Seul, un passage du point de transformation {alpha}-{beta} efface rapidement l'effet de l'irradiation. 2- Durcissement de l'uranium par irradiation. Nous avons, a l'aide de la durete, etudie plus particulierement l'effet de tres faibles irrtions sur l

  15. Fundamental irradiation studies on vanadium alloys

    Loomis, B.A.; Garner, F.A.; Ermi, A.M.

    1985-05-01

    A joint experiment on the irradiation response of simple vanadium alloys has been initiated under the auspices of the DAFS and BES progams. Specimen fabrication is nearly complete and the alloys are expected to be irradiated in lithium in FFTF-MOTA Cycles 7 and 8

  16. Cherry Irradiation Studies. 1984 annual report

    Eakin, D.E.; Hungate, F.P.; Tingey, G.L.; Olsen, K.L.; Fountain, J.B.; Burditt, A.K. Jr.; Moffit, H.R.; Johnson, D.A.; Lunden, J.D.

    1985-04-01

    Fresh cherries, cherry fruit fly larvae, and codling moth larvae were irradiated using the PNL cobalt-60 facility to determine the efficacy of irradiation treatment for insect disinfestation and potential shelf life extension. Irradiation is an effective disinfestation treatment with no significant degradation of fruit at doses well above those required for quarantine treatment. Sufficient codling moth control was achieved at projected doses of less than 25 krad; cherry fruit fly control, at projected doses of less than 15 krad. Dose levels up to 60 krad did not adversely affect cherry quality factors tested. Irradiation above 60 krad reduced the firmness of cherries but had no significant impact on other quality factors tested. Irradiation of cherries below 80 krad did not result in any significant differences in sensory evaluations (appearance, flavor, and firmness) in tests conducted at OSU. Irradiation up to 200 krad at a temperature of about 25 0 C (77 0 F) did not measurably extend shelf life. Irradiation at 500 krad at 25 0 C (77 0 F) increased mold and rotting of cherries tested. There is no apparent advantage of irradiation over low-temperature fumigation

  17. Meso-scale magnetic signatures for nuclear reactor steel irradiation embrittlement monitoring

    Suter, J. D., E-mail: pradeep.ramuhalli@pnnl.gov; Ramuhalli, P., E-mail: pradeep.ramuhalli@pnnl.gov; Hu, S.; Li, Y.; Jiang, W.; Edwards, D. J.; Schemer-Kohrn, A. L.; Johnson, B. R. [Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99352 (United States); McCloy, J. S., E-mail: john.mccloy@wsu.edu; Xu, K., E-mail: john.mccloy@wsu.edu [Washington State University, PO Box 642920, Pullman, WA 99164 (United States)

    2015-03-31

    Verifying the structural integrity of passive components in light water and advanced reactors will be necessary to ensure safe, long-term operations of the existing U.S. nuclear fleet. This objective can be achieved through nondestructive condition monitoring techniques, which can be integrated with plant operations to quantify the “state of health” of structural materials in real-time. While nondestructive methods for monitoring many classes of degradation (such as fatigue or stress corrosion cracking) are relatively advanced, this is not the case for degradation caused by irradiation. The development of nondestructive evaluation technologies for these types of degradation will require advanced materials characterization techniques and tools that enable comprehensive understanding of nuclear reactor material microstructural and behavioral changes under extreme operating environments. Irradiation-induced degradation of reactor steels causes changes in their microstructure that impacts their micro-magnetic properties. In this paper, we describe preliminary results of integrating advanced material characterization techniques with meso-scale computational models. In the future, this will help to provide an interpretive understanding of the state of degradation in structural materials. Microstructural data are presented from monocrystalline Fe and are correlated with variable-field magnetic force microscopy and micro-magnetic measurements. Ongoing research is focused on extending the measurements and models on thin films to gain insights into the structural state of irradiated materials and the resulting impact on magnetic properties. Preliminary conclusions from these correlations are presented, and next steps described.

  18. Comprehensive studies on irradiated single-crystal diamond sensors

    Stegler, Martin [DESY, Zeuthen (Germany)

    2015-07-01

    Single-crystal diamond sensors are used as part of the Beam and Radiation Instrumentation and Luminosity (BRIL) projects of the CMS experiment. Due to an upgrade of the Fast Beam Conditions Monitor (BCM1F) these diamond sensors are exchanged and the irradiated ones are now used for comprehensive studies. Current over voltage (IV), current over time (CT) and charge collection efficiency (CCE) measurements were performed for a better understanding of the radiation damage incurred during operation and to compensate in the future. The effect of illumination with various light sources on the charge collection efficiency was investigated and led to interesting results. Intensity and wavelength of the light were varied for deeper insight of polarization effects.

  19. Studies on the improvement of irradiation process

    Kim, Ki Yup; Pyun, Hyung Chick; Yoon, Byung Mok; Nho, Young Chang; Lee, Young Keun; Park, Soon Chul; Na, Bong Joo; Yoo, Young Soo

    1991-01-01

    On the basis of analysis and examination for efficient maintenance and operation of the facility, the method of improving irradiation process was discussed so that we may extend the applicability of irradiation technique to various materials and accelerate nation-wide propagation of radiation processing technology. Preparations have been made for transfer, installation, and operation of the irradiation facilities in radiation application building which will be completed at the headquarter site by the end of 1992. The qualification testing apparatus for nuclear power station cables was conceptually designed to investigate the degradation behavior of the cables under a simulated LOCA(Loss of Coolant Accident) environments. (Author)

  20. Wholesomeness studies in the International Food Irradiation Project

    Elias, P S [International Food Irradiation Project, Federal Research Centre for Nutrition

    1980-01-01

    Despite more than 25 years of history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and scientific investigations are required to provide reassurance as to the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subjects for the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans.

  1. Study for the identification of irradiated carbohydrate containing food

    Scherz, H.

    1991-01-01

    The study was undertaken to find radiation specific substances of carbohydrates and methods to detect those ones in irradiated food. Deoxycompounds have been found by irradiation of carbohydrates. It could be stated, that the formation of these substances was radiation specific. The irradiation of wheat for desinfestation was high actual at the moment of this study and therefore it was tried to find these deoxycompounds in irradiated potato starch and wheat flour. These substances were isolated and one of them was identified as w-hydroxymaltol. This substance was also found in irradiated wheat flour. The dependence between the amount of w-hydroxymaltol and the irradiation dosage was determined for both materials. (7 refs, 2 figs)

  2. Study of irradiation damage structures in austenitic stainless steels

    Hamada, Shozo

    1997-08-01

    The irradiation damage microstructures in austenitic stainless steels, which have been proposed to be a candidate of structural materials of a fusion reactor, under ions and neutrons irradiation have been studied. In ion irradiation experiments, cross-sectional observation of the depth distribution of damage formed due to ion irradiation became available. Comparison and discussion between experimental results with TEM and the calculated ones in the depth profiles of irradiation damage microstructures. Further, dual-phase stainless steels, consisted of ferritic/austenitic phases, showed irradiation-induced/enhanced precipitation during ion irradiation. High Flux Isotope Reactor with high neutron fluxes was employed in neutron-irradiation experiments. Swelling of 316 steel showed irradiation temperature dependence and this had strong correlation with phase instability under heavy damage level. Swelling resistance of Ti-modified austenitic stainless steel, which has good swelling resistance, decreased during high damage level. This might be caused by the instability of Ti-carbide particles. The preparation method to reduce higher radioactivity of neutron-irradiated TEM specimen was developed. (author). 176 refs

  3. Study of irradiation damage structures in austenitic stainless steels

    Hamada, Shozo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-08-01

    The irradiation damage microstructures in austenitic stainless steels, which have been proposed to be a candidate of structural materials of a fusion reactor, under ions and neutrons irradiation have been studied. In ion irradiation experiments, cross-sectional observation of the depth distribution of damage formed due to ion irradiation became available. Comparison and discussion between experimental results with TEM and the calculated ones in the depth profiles of irradiation damage microstructures. Further, dual-phase stainless steels, consisted of ferritic/austenitic phases, showed irradiation-induced/enhanced precipitation during ion irradiation. High Flux Isotope Reactor with high neutron fluxes was employed in neutron-irradiation experiments. Swelling of 316 steel showed irradiation temperature dependence and this had strong correlation with phase instability under heavy damage level. Swelling resistance of Ti-modified austenitic stainless steel, which has good swelling resistance, decreased during high damage level. This might be caused by the instability of Ti-carbide particles. The preparation method to reduce higher radioactivity of neutron-irradiated TEM specimen was developed. (author). 176 refs.

  4. Irradiation capsule design capable of continuously monitoring the creepdown of Zircaloy fuel cladding

    Thoms, K.R.; Dodd, C.V.; van der Kaa, T.; Hobson, D.O.

    1978-01-01

    An irradiation capsule which permits continuous monitoring of the creepdown of Zircaloy tubing has been designed and given preliminary tests. This design effort is the major element of a cooperative research program between the United States Nuclear Regulatory Commission and the Netherlands Energy Research Foundation (ECN) and is a part of the NRC-sponsored Zircaloy creepdown program. The purpose of the Zircaloy creepdown program is to provide data on the deformation characteristics of Zircaloy tubes, typical of LWR fuel element cladding, under combined axial and tangential compressive stresses. These data will be used to verify and improve the material behavior codes that are used for the description of fuel pin behavior. The first capsule of this series contains a mockup test specimen which was machined with three different diameters, nominally 10.92-mm, 10.54-mm and 11.30-mm (.430-in., .415-in., and .445-in.). This test specimen can be moved axially thereby varying the lift-off and serving as a calibration device for the eddy-current deformation monitoring probes. Fabrication of this capsule has been completed and during out-or-reactor checkout we were able to obtain a resolution of better than 0.01-mm (0.0004-in.). The capsule is scheduled for installation in the HFR on February 8, 1978, for a 26 day irradiation test. The first pressurized capsule, and therefore the first one to monitor in-reactor cladding deformation, will be installed in the HFR on May 3, 1978

  5. NMR studies of defects created by irradiation in metals

    Minier, M.; Minier, C.

    1983-06-01

    Nuclear Magnetic Resonance has been rarely used to study point defects created by irradiation in metals. Information obtained in this field using N.M.R. are shown. Some results are also described: characterization of migrating defects in electron irradiated copper; mobility of the complex interstitial-impurity in Al with 150 ppm of chromium; interstitial structure in irradiated aluminum and autodiffusion in metals [fr

  6. Electron spin resonance studies of some irradiated pharmaceuticals

    Gibella, M.; Crucq, A-S.; Tilquin, B.; Stocker, P.; Lesgards, G.; Raffi, J.

    2000-01-01

    Five antibiotics belonging to the cephalosporins and penicillins groups have been irradiated: anhydrous ampicilline acid, amoxicilline acid trihydrate, cefuroxime sodium salt, cloxacilline sodium salt monohydrate and ceftazidime pentahydrate. ESR studies have been carried out, showing the influence of irradiation and storage parameters on the nature and concentration of the free radicals trapped. These results may be used to detect an irradiation treatment on such pharmaceuticals. (author)

  7. Wholesomeness study of irradiated salted and dried mackerel in rats

    Anukarahanonta, T.; Temcharoen, P.; Nagara, B.N.; Chudhabuddhi, C.; Bhamarapravati, N.

    1981-01-01

    A long-term multigeneration study was performed of the wholesomeness of irradiated salted and dried mackerel fed to the rats of Wistar strain and revealed no significant evidence that would impose a hazard attributable to irradiation with respect to the longevity, carcinogenecity, teratogenicity, dominant lethal, reproductive function and biophysiological function. Some abnormalities that were noted could be explained on the basis of differences in food quality due to the addition of fish protein and minerals rather than the irradiation effect

  8. Development of fabrication method for thermal expansion difference irradiation temperature monitor

    Noguchi, Kouichi; Takatsudo, Hiroshi; Miyakawa, Shun-ichi; Kobori, Takahisa; Miyo, Toshimasa

    1998-03-01

    This report describes the development activities for the fabrication of the Thermal Expansion Difference irradiation temperature monitor (TED) at the Oarai Engineering Center (OEC)/PNC. TED is used for various irradiation tests in the experimental fast reactor JOYO. TED is the most accurate off-line temperature monitor used for irradiation examination. The TED is composed of a metallic sphere lid and either a stainless steel or nickel alloy container. Once the container is filled with sodium, the metallic sphere lid is sealed by using a resistance weld. This capsule is then loaded into a reactor. Once a TED is loaded into the JOYO reactor, the sodium inside the metallic container increases as a result of thermal expansion. The TED identifies the peak irradiation temperature of the reactor based on a formula correlating temperature to increment values. This formula is established specifically for the particular TED being used during a calibration process performed when the TED is fabricated. Initially the TED was developed by Argonne National Laboratory (ANL) in the United States, and was imported by PNC for use in the JOYO reactor. In 1992 PNC decided to fabricate TED domestically in order to ensure the stability of future supplies. Based on technical information provided by ANL, PNC began fabrication of a TED on an experimental basis. In addition, PNC endeavored to make the domestically produced TED more efficient. This involved improving the techniques used in the sodium filling and the metallic sphere welding processes. These quality control efforts led to PNC's development of processes enabling the capsules to be filled with sodium to nearly 100%. As a result, the accuracy of the temperature dispersion in the out-pile calibration test was improved from +/-10degC to +/-5degC. In 1996 the new domestically fabricated TED was attached to a JOYO irradiation rig. In March of 1997, irradiation of the rig was started on the 30th duty cycle operation, and should be

  9. Study on silk yellowing induced by gamma-irradiation

    Tsukada, Masuhiro; Aoki, Akira

    1985-01-01

    The changes in the yellow color of silk threads with total dose of irradiation applied were described and studied by a colorimetric method and by monochrome photography. The change into a yellow color of the specimen in the course of irradiation was clearly detected in photographs using filters, 2B and SC 56 under light conditions at the wavelength of 366 nm. The b/L value measured by colorimetry in undegummed and degummed silk fibers sharply increased in the early stage of irradiation. Yellow color indices (b/L) of the specimen subjected to gamma-irradiation continued to increase and the yellow color of the silk threads became more pronounced above a total dose of irradiation of 21 Mrad. The b/L value of the undegummed silk fiber which had deen irradiated was about 2 times that of the degummed silk fiber. (author)

  10. Study on determination method of identifying irradiated chicken

    Guo Liping; Yu Xuejun; Yu Menghong; Fu Junjie; Zhang Shimin; Bao Jinsong

    2003-01-01

    The effects of gamma irradiation on the activities of aleipsis, peroxidase, perhydrol catalase and the peroxide values in chicken oil and effects of different storage time on self-oxidation of fat and lipa in irradiated chicken were studied. The results showed that the activities of aleipsis and perhydrol catalase in irradiated chicken decreased with increasing doses, and the peroxide activity and peroxide value of lipa increased with increase of doses. No significant effect of storage time on peroxide value was observed in the irradiated chicken

  11. Stereophotogrammetric study of surface topography in ion irradiated silver

    Sokolov, V.N.; Fayazov, I.M.

    1993-01-01

    The irradiated surface topography of polycrystalline silver was studied using the stereophotogrammetric method. The surface of silver was irradiated with 30 keV argon ions at variation for the ion incidence angle in interval of 0-80 deg relative to a surface normal. The influence of the inclination angle of the sample in the SEM on the cone shape of a SEM-picture of the irradiated surface is discussed. The parameters of cones on the irradiated surface of silver were measured by the SEM-stereomethod. The measurements of the sample section perpendicular to the incidence plane are also carried out

  12. Echographic monitoring of response of extraocular muscles to irradiation in graves' ophthalmopathy

    Erickson, Beth A.; Harris, Gerald J.; Lewandowski, Michael F.; Murray, Kevin J.; Massaro, Bruce M.

    1995-01-01

    Purpose: Confirmation of the efficacy of orbital irradiation in Graves' ophthalmopathy is needed due to the unpredictable natural history of the disease, the variation in individual clinical presentations, the contribution of other simultaneous treatments, and the lack of controlled studies using objective criteria to classify and assess response over time. Orbital echography before and at select intervals following orbital irradiation is proposed as an objective parameter of tissue response to orbital irradiation over time. Methods and Materials: From January, 1983 to September, 1993, 55 patients with progressive Graves' ophthalmopathy underwent 20 Gy retrobulbar irradiation. On retrospective review, standardized orbital echography was performed randomly prior to irradiation in 37 of the 55 patients to assess the acoustic characteristics of the extraocular muscles and to quantitate their individual and summed diameters. Twenty-one patients had at least one follow-up echographic evaluation at random intervals of 0 to 27.5 months following completion of irradiation. Twelve patients received steroids before or during irradiation, which were tapered in proximity to completion of radiation. Follow-up ranged from 2 to 65 months with the majority followed at least 6 months (18 patients). Results: Of the 21 patients with serial studies, 18 showed an interval decrease in individual and summed muscle size over time and return of symmetry. Interval improvement was documented as early as the 1 month follow-up study, with continued improvement seen during the 3-9 month studies, with stability typically achieved within 12 months. One patient had further changes between the 21 and 27.5 month follow-up studies. Exacerbation of disease was, however, echographically demonstrated in three patients at 6.5, 8.5, and 13 months. Follow-up studies in two of these patients again revealed improvement, one following tapered steroids. The third patient required orbital decompression

  13. Studies on the storage of irradiated potatoes

    Sharabash, M; Orabi, I O [National Center for research and radiation Technology, Nasr City, Cairo (Egypt); Eloksh, I I; Abd-Alia, M A [Faculty of Agric. Ain Shams University, Cairo (Egypt)

    1995-10-01

    Tubers of alpha and king edward potato cultivars were exposed to O, 10 or 50 krad and stored under room temperature and good ventilation in perforated standard carton boxes. 10 Krad was the promising dosage for sprouting inhibition for both the two cultivars. Total losses in weight were partially dependent on the volume of the dosage, the time elapsed after irradiation and cultivar used. Ascorbic acid slightly decreased, whilst sugar fractions were increased during storage in irradiated tubers. Sugar fractions were sharply decreased in boiled or fried potatoes. Also, chlorogenic acid was increased by prolonging the storage time and/or increasing the exposure dose. After-cooking discoloration (darkening) was reduced by gamma irradiation and/or extending the storage period. Using 0.5% citric acid or 0.5% sodium citrate solution inhibited the after-cooking discoloration. 8 tabs.

  14. Studies on the storage of irradiated potatoes

    Sharabash, M.; Orabi, I.O.; Eloksh, I.I.; Abd-Alia, M.A.

    1995-01-01

    Tubers of alpha and king edward potato cultivars were exposed to O, 10 or 50 krad and stored under room temperature and good ventilation in perforated standard carton boxes. 10 Krad was the promising dosage for sprouting inhibition for both the two cultivars. Total losses in weight were partially dependent on the volume of the dosage, the time elapsed after irradiation and cultivar used. Ascorbic acid slightly decreased, whilst sugar fractions were increased during storage in irradiated tubers. Sugar fractions were sharply decreased in boiled or fried potatoes. Also, chlorogenic acid was increased by prolonging the storage time and/or increasing the exposure dose. After-cooking discoloration (darkening) was reduced by gamma irradiation and/or extending the storage period. Using 0.5% citric acid or 0.5% sodium citrate solution inhibited the after-cooking discoloration. 8 tabs

  15. Economic study of rice irradiation in egypt

    Elkhateeb, M.A.; Elgmeel, E.A.

    2004-01-01

    The paper discusses the economics of rice irradiation and the effect of various parameters on unit processing costs. It provides a model for calculating specific unit processing costs by correlating known capital costs with annual operation cost and annual throughputs. It is intended to provide the investors with a general knowledge of how unit processing costs are derived. The investment criteria utilized for commercial evaluation were internal rate of return (I.I.R), pay back period (P.B.P), and average rate of return (A.R.R). The irradiation cost and the additional income are also discussed. The result of the analysis showed that the installation of an irradiation unit in Egypt would be economically feasible

  16. Thermal Decompositon Studies Of Pre-Irradiated Nickel (II) Azides ...

    The effect of pre-irradiation on the thermal decomposition of three samples of nickel (II) azide was studied. It was found that the rates of thermal decomposition of Ni(OH)N3 increased substantially with increase in pre-irradiation dosage. The initial reaction rates change from time-dependant nucleation law for the unirradiated ...

  17. Preliminary study on irradiation breeding of ornamental lotus

    Chen Xiulan; Bao Jianzhong; Liu Chungui; Cao Hong; Zhai Jianqing

    2004-01-01

    The effects of γ-ray irradiation on seeds and stems of ornamental lotus were studied. The results show that the mutation rate of seeds is higher than that of stems, and 30-60 Gy is the appropriate irradiation dose. The varieties with red or multi-color flower are more mutable than those with white flower. Two varieties were selected

  18. Monitoring PAI-1 and VEGF Levels in 6 Human Squamous Cell Carcinoma Xenografts During Fractionated Irradiation

    Bayer, Christine; Kielow, Achim; Schilling, Daniela; Maftei, Constantin-Alin; Zips, Daniel; Yaromina, Ala; Baumann, Michael; Molls, Michael; Multhoff, Gabriele

    2012-01-01

    Purpose: Previous studies have shown that the plasminogen activator inhibitor type-1 (PAI-1) and vascular endothelial growth factor (VEGF) are regulated by hypoxia and irradiation and are involved in neoangiogenesis. The aim of this study was to determine in vivo whether changes in PAI-1 and VEGF during fractionated irradiation could predict for radiation resistance. Methods and Materials: Six xenografted tumor lines from human squamous cell carcinomas (HSCC) of the head and neck were irradiated with 0, 3, 5, 10, and 15 daily fractions of 2 Gy. The PAI-1 and VEGF antigen levels in tumor lysates were determined by enzyme-linked immunosorbent assay kits. The amounts of PAI-1 and VEGF were compared with the dose to cure 50% of tumors (TCD 50 ). Colocalization of PAI-1, pimonidazole (hypoxia), CD31 (endothelium), and Hoechst 33342 (perfusion) was examined by immunofluorescence. Results: Human PAI-1 and VEGF (hVEGF) expression levels were induced by fractionated irradiation in UT-SCC-15, UT-SCC-14, and UT-SCC-5 tumors, and mouse VEGF (msVEGF) was induced only in UT-SCC-5 tumors. High hVEGF levels were significantly associated with radiation sensitivity after 5 fractions (P=.021), and high msVEGF levels were significantly associated with radiation resistance after 10 fractions (P=.007). PAI-1 staining was observed in the extracellular matrix, the cytoplasm of fibroblast-like stroma cells, and individual tumor cells at all doses of irradiation. Colocalization studies showed PAI-1 staining close to microvessels. Conclusions: These results indicate that the concentration of tumor-specific and host-specific VEGF during fractionated irradiation could provide considerably divergent information for the outcome of radiation therapy.

  19. Consequences of cytoplasmic irradiation. Studies from microbeam

    Zhou, Hongning; Hong, Mei; Chai, Yunfei; Hei, Tom K.

    2009-01-01

    The prevailing dogma for radiation biology is that genotoxic effects of ionizing radiation such as mutations and carcinogenesis are attributed mainly to direct damage to the nucleus. However, with the development of microbeam that can target precise positions inside the cells, accumulating evidences have shown that energy deposit by radiation in nuclear DNA is not required to trigger the damage, extra-nuclear or extra-cellular radiation could induce the similar biological effects as well. This review will summarize the biological responses after cytoplasm irradiated by microbeam, and the possible mechanisms involved in cytoplasmic irradiation. (author)

  20. A microbiological study on irradiated sludge composting

    Pongpat, S.; Hashimoto, Shoji.

    1993-03-01

    Effect of fermentation temperature on microorganisms in sewage sludge compost and suppressive effect of the compost on Fusarium oxysporum were investigated. Dehydrated sewage sludge was irradiated at 10 kGy by cobalt 60 gamma ray source and fermented at various temperatures with six different seed-composts. It was found that microorganisms showed higher growth in irradiated sludge at the temperature around 30 to 40degC. One of the seed-composts and compost produced from the seed-compost showed the remarkable effects of suppression on F. oxysporum. It can be also observed that the composts produced by lower temperature fermentation showed higher suppression. (author)

  1. A microbiological study on irradiated sludge composting

    Pongpat, S. [Office of Atomic Energy for Peace, Bangkok (Thailand); Hashimoto, Shoji

    1993-03-01

    Effect of fermentation temperature on microorganisms in sewage sludge compost and suppressive effect of the compost on Fusarium oxysporum were investigated. Dehydrated sewage sludge was irradiated at 10 kGy by cobalt 60 gamma ray source and fermented at various temperatures with six different seed-composts. It was found that microorganisms showed higher growth in irradiated sludge at the temperature around 30 to 40degC. One of the seed-composts and compost produced from the seed-compost showed the remarkable effects of suppression on F. oxysporum. It can be also observed that the composts produced by lower temperature fermentation showed higher suppression. (author).

  2. Facilities for studying radiation damage in nonmetals during irradiation

    Levy, P.W.

    1984-08-01

    Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses 60 Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at controlled temperatures between 5K and 900 0 C. The materials studied include glasses, quartz, alkali halides (especially natural rock salt), organic crystals, etc. As determined from color center measurements the damage formation rate in all materials studied at 25 0 C or above is strongly temperature dependent. The defect concentration during irradiation is usually much greater than that measured after irradiation. The fraction of defects annealing after irradiation and the annealing rate usually increases as the irradiation temperature increases. The completed studies demonstrate that, in most cases, the extent of maximum damage and the damage formation and annealing kinetics can be determined only by making measurements during irradiation

  3. Study on biologically active substances in irradiated apple juice

    Tencheva, S.

    1975-01-01

    The radiochemical changes proceeding by irradiation of foodstuffs rich in carbohydrates are studied. For the purpose pure solutions of D-glucose, D-fructose and sucrose and fresh apple juice, irradiated with 0,5 and 1,0 Mrad are investigated. Changes set in UV-spectra of the irradiated foodstuffs, the specific reaction of malonic dialdehyde formation with 2-thiobarbituric acid and the formation of carbonyl compounds reacting with 2,4-dinitro phenylhydrazine are studied. Results show that in the irradiated sample solutions of sugars and apple juice two peaks are formed. The malonic dialdehyde formation depends on the dose of irradiation applied. The newly formed carbonyl compounds both in the sample solutions and in the juice are 8 to 9 in number. (author)

  4. Study on the sterilization of egg white powder by irradiation

    Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Wang Zhidong

    2013-01-01

    The sterilizing effect, influence on main essential nutrient and sensory qualities of egg white powder treated with 60 Co γ-ray irradiation were studied. The microorganism index of egg white powder samples treated with 4 kGy irradiation could meet the government food sanitation standard, and the sterilization rate could reach 100%. The irradiation doses from 4 to 10 kGy had little influence on egg white powder protein, crude fiber and amino acidscontent, and the sensory quality such as color, luster, and scent changed little below 6 kGy irradiation. Considering the result of this study, the optimal irradiation dose for egg white powder sterilization was 4 to 6 kGy. (authors)

  5. Study of bixin oxidation by ionizing irradiation

    Fonseca, Thais N.; Teixeira, Paula S.; Moura, Eduardo de; Geraldo, Áurea Beatriz C.

    2017-01-01

    Brazil is the world's largest producer of anatto, followed by Kenya and Peru. The fruit of the annatto tree is constituted by a capsule containing external spines and internal seeds with reddish coloration, providing a natural pigment which is environmentally efficient, being able to replace synthetic pigments and dyes. The active substance of the pigment is Bixin, which is a type of carotenoid which constitutes a greater percentage of pigment in these seeds and has a lipo soluble character. Bixin reacts with NaOH in a saponification reaction giving norbixin, which is water soluble. It is known that the destination of the dye extracted from the fruit is intended for industry, especially the food industry. The culture of annatto tree brings prospects of development in agricultural programs for medium and small producers, which are able to use decadent areas of other crops. In addition to the food sector, new applications for the pigment helps the development of family farming. The pigment extracted from annatto undergoes a natural oxidation; this work aims to evaluate this phenomenon and also the oxidation of the pigment after the irradiation process. This work also evaluates of the how the oxidation process is affected by irradiation and the modifications introduced to irradiated pigments. Irradiated and nonirradiated samples were characterized by thermogravimetry, UV-vis spectrophotometry and infrared spectroscopy (FTIR). The results are then discussed. (author)

  6. Study on the improvement of irradiation process

    Jin, Joon Ha; Yoon, Byung Mok; Kim, Ki Yup; Nho, Young Chang; Lee, Young Keun; Park, Soon Chul; Na, Bong Joo; Yoo, Young Soo

    1993-02-01

    The source operation system, carrier systems, safety systems and all other miscellaneous systems were installed for the High Intensity Co-60 Gamma Irradiation Facility. The Co-60 Source(72,800 Ci) was installed on the source rack by Canadian engineers and the facility was approved to be safe after some test operations. The acceleration tube, transformer, main control panel and high voltage cable were installed in the Electron Accelerator Facility. All parts of the accelerator were inspected and repaired. The Low Intensity Co-60 Gamma Irradiator in Seoul was dismantled for moving to Taejon and source operation and safety systems were prepared for the new facility. During the installations, old parts and equipments of each irradiation facility were replaced and many improvement were made on the systems by installing the irradiation tables and experimental holes, movements of control and machine room and ventilation fans to each reasonable position, and installation of additional fire alarm system and cable terminal box. The knowledge and experiences obtained during the installations will be very helpful for the operation and maintenance of the facilities in the future. The facilities will be utilized for the various researches and application fields such as polymer, food agriculture, biology, equipment qualification, etc. (Author)

  7. Towards a Unified Environmental Monitoring, Control and Data Management System for Irradiation Facilities: the CERN IRRAD Use Case

    Gkotse, Blerina; Jouvelot, Pierre; Matli, Emanuele; Pezzullo, Giuseppe; Ravotti, Federico

    2017-01-01

    The qualification of materials, electronic components and equipment for the CERN High Energy Physics experiments and beyond requires testing against possible radiation effects. These quite complex tests are performed by specialized teams working in irradiation facilities such as IRRAD, the Proton Irradiation Facility at CERN. Building upon the details of the overall irradiation control, monitoring, and logistical systems of IRRAD as a use case, we introduce the motivations for and general architecture of its new data management framework, currently under development at CERN. This infrastructure is intended to allow for the seamless and comprehensive handling of IRRAD irradiation experiments and to help manage all aspects of the facility. Its architecture, currently focused on the specific requirements of the IRRAD facility, is intended to be upgraded to a general framework that could be used in other irradiation facilities within the radiation effects community, as well as for other applications.

  8. Positron annihilation studies on reactor irradiated and thermal annealed ferrocene

    Marques Netto, A.; Carvalho, R.S.; Magalhaes, W.F.; Sinisterra, R.D.

    1996-01-01

    Retention and thermal annealing following (n, γ) reaction in solid ferrocene, Fe(C 5 H 5 ) 2 , were studied by positron annihilation lifetime spectroscopy (PAL). Positronium (Ps) formation was observed in the non-irradiated compound with a probability or intensity (I 3 ) of 30%. Upon irradiation of the compound with thermal neutrons in a nuclear reactor, I 3 decreases with increasing irradiation time. Thermal treatment again increases I 3 values from 16% to 25%, revealing an important proportion of molecular reformation without variation of the ortho-positronium lifetime (τ 3 ). These results point out the major influence of the electronic structure as determining the Ps yields in the pure complex. In the irradiated and non irradiated complexes the results are satisfactorily explained on the basis of the spur model. (orig.)

  9. Study on the sterilization of egg white powder by irradiation

    Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Pei Ying

    2011-01-01

    The article studied the killing microorganism result, the influence of main essential nutrient and sense organ of egg white powder by Co-60 γ-ray irradiation. The microorganism index of the egg white powder samples can meet the government food 1 sanitation standard by 4 kGy irradiation, and the killing microorganism rare can reach 100%. The irradiation dose from 4 to 10 kGy has little influence to the egg white powder protein, crude fiber and amino acids contrasting to comparison, and the sensory quality such as color and luster, scent has little change below 6 kGy irradiation. Compositing the result of physical chemistry and sense organ, the optimal irradiation dose of egg white powder killing microorganism is 4 to 6 kGy. (authors)

  10. Study on the sterilization of egg white powder by irradiation

    Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Pei Ying

    2012-01-01

    The article studied the killing microorganism result, the influence of main essential nutrient and sense organ of egg white powder by Co-60 γ-ray irradiation. The microorganism index of the egg white powder samples can meet the government food sanitation standard by 4 kGy irradiation, and the killing microorganism rare can reach 100%. The irradiation dose from 4 to 10 kGy has little influence to the egg white powder protein, crude fiber and amino acids contras ting to comparison, and the sensory quality such as color and luster, scent has little change below 6 kGy irradiation. Synthesizing the results of physical chemistry and sense organ, the optimal irradiation dose of egg white powder killing microorganism is 4 to 6 kGy. (authors)

  11. Study on irradiation preservation of frozen shelled shrimps

    Liu Chunquan; Zhu Jiating; Zhao Yongfu; Yu Gang; Zhang Weidong; Jin Yudong; Ji Ping

    2004-01-01

    The effect of irradiaiton preservation of frozen shelled shrimps for export was studied. The microbial indexd, nutritional ingredient, physico-chemical index for irradiation frozen shelled shrimps were detected. The results showed that 3-5 kGy irradiation dose could kill more than 99% of all kinds of microorganisms in frozen shelled shrimps, the content of most amino acids in shelled shrimps increased, after being irradiated by 1-9 kGy dose, the total amino acids had been obvisouly higher than CK, the increased range was 0.33%-24.6%, the content of the total volatile basic nitrogen (TVBN) decreased. Compared with the CK, the content of the heavy metal elements etc had no obvious change, the presrvation duration of irradiated shelled shrimp was twelve months longer than that of CK when storage temperature was under -7 degree C soft frozen, Compared with -18 degree C the effect of irradiation preservation had no obvious change. (authors)

  12. [Alaskan commodities irradiation project: An options analysis study

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.

    1989-09-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology

  13. Experimental and theoretical study of solid solution stability under irradiation

    Cauvin, Richard.

    1981-08-01

    The behavior of dilute alloys (Al-Zn, Al-Ag, Al-Si, Al-Ge and Al-Mg) under 1 MeV electron irradiation has been studied in a high voltage electron microscope. A phenomenon of homogeneous precipitation induced by irradiation in undersaturated solid solutions (Al-Zn, Al-Ag and Al-Si) has been discovered; the observed precipitates are either coherent or incoherent, but never associated with point defect sinks. The solubility limit is a function of irradiation temperature and flux; but, under irradiation, it does not behave as a true thermal solubility limit (without irradiation). The existing theories (kinetic or strictly thermodynamic) do not account for this phenomenon. It is shown that the irreversibility of the mutual recombination between trapped vacancies and mixed interstitials is the driving force of this homogeneous precipitation. Using a dilute solid solution model, we show that, under irradiation, the homogeneous stationary state, stable from a strictly thermodynamic point of view, can be unstable when the recombination reaction is taken into account. The solubility limit under irradiation is calculated with a nucleation-growth model taking account for this effect; it is proportional to the thermal solubility limit without irradiation. This model explains all the experimental observations [fr

  14. Intraesophageal impedance monitoring: clinical studies

    Conchillo Armendáriz, J.M.

    2007-01-01

    Electrical impedance (Z) between two electrodes is the ratio between applied voltage (U) and resulting current (I). In electrical impedance monitoring the resistance to electrical flow in an alternating current circuit is measured. Multichannel esophageal monitoring can be measured by using an

  15. Consumer studies acceptability on irradiated food

    Lescano, G.

    1987-01-01

    A questionary to 119 professionals connected with the food field was performed in order to know their attitude, doubts and concernings about food irradiation considering that a favourable opinion would produce trust to the consumer market. The first part of the questionary showed the following results: 13% had never heard about food irradiation (FI), 72% were few familiarized with it, and 14% knew the subject; 42% would accept FI, 37% probably would accept it, 19% could not make up their minds and 2% would not accept it; 45% would eat irradiated food (IF), 45% probably would eat it, 8% probably would not eat it and 2% would not eat it; 44% would serve IF in their home, 45% would probably do so, 8% would probably not do it, and 3% would not do it. The second part showed that 67% of people thought that ionizing radiation (IR) improved the sanitary quality of food, 3% did not think so, and 29% did not know; 63% thought that IR is preferible to chemical preservatives, 4% did not think so and 33% did not know; 11% thought that the food treated with IR becomes radioactive, 60% did not think so, and 29% did not know; 42% thought that FI is wholesome, 8% did not think so, and 50% did not know; 8% consider that the majority of the persons would eat IF, 40% did not think so and 52% did not know; 82% consider necessary that IF have an identificatory label, 10% did not think so, and 8% did not know; 95% consider necessary more diffusion of this method before its commercialization, 2% did not think so and 3% did not know, and 81% want more information, 18% would want it and 1% do not want it. These results are considered to be a good sign of future consumption acceptability of food irradiation. (Author)

  16. Studies On Quality Criteria For Irradiated Breaded Chicken Breast Fillets

    HASSAN, I.M.; IBRAHIM, M.T.; MAHMOUD, A.A.; SHAMS EL DIN, N.M.M.; MOHAMMAD, M.K.

    2010-01-01

    Quality criteria of irradiated breaded chicken breast fillets were studied. Fresh boneless and skinless breaded chicken breast meats samples were divided into four separate batches and packed in plastic bags and sealed by an impulse sealer. Samples in plastic bags were exposed to different doses of gamma irradiation (2.5, 5 and 7 kGy) at ambient temperature. Just after irradiation, the samples were stored at 4 ±1 0 C. All samples were evaluated for microbiological, chemical and sensorial properties after irradiation and throughout the storage periods. During storage, the total bacterial count was significantly increased (P<0.05) in all samples with higher rates of increase in non-irradiated samples. In all irradiated samples, Staphylococcus aureus did not detected up to 6 days then detected after 22 days in samples treated with 2.5 kGy as well as 31 days in samples treated with 5 kGy. On the other hand, Staphylococcus aureus was detected after 45 days in samples treated with 7 kGy. Salmonella sp., Listeria monocytogenes and Campylobacter jejuni could not detected in untreated and treated samples. The protein content showed significant decrease immediately after irradiation and during the refrigerated storage. The TVN values for non-irradiated samples were significantly higher (P<0.05) than irradiated samples. The present data showed significant decrease (P<0.05) in protein solubility percentages of irradiated samples at day 0 and 6 of refrigerated storage. The observed decrease was related to the increase of radiation dose. At the end of storage period (62 days), 2.5 kGy samples were significantly higher in TBA values than other irradiated samples. On the other hand, irradiation was significantly reduced (P<0.05) the amount of major mono unsaturated and poly unsaturated fatty acids. Sensory attributes of breaded chicken breast fillets did not affected by irradiation. It could be concluded that irradiation dose of 5 kGy can be used in chicken samples stored in

  17. Study on sensory test of irradiated spices

    Chiba, Etsuko; Iizuka, Tomoko; Ichikawa, Mariko; Kobayashi, Yasuhiko; Ukai, Mitsuko; Kikuchi, Masahiro

    2016-01-01

    For the spices used in curry dishes and the spices used except for curry dishes, the effects of irradiation sterilization and conventional superheated-steam sterilization were compared with sensory test. As for spices, superheated-steam sterilization reduces aroma and changes color tone compared with irradiation sterilization. Even with cooked curry, radiologically sterilized products were stronger in 'flavor before sample tasting' or 'spicy taste during sample tasting' with statistically significant difference compared with superheated-steam sterilized products. As for the comparison with spices themselves, red pepper and white/black pepper tended to be stronger in taste and pungent taste than radiologically sterilized products. In addition, superheated-steam sterilized products of red hot pepper and turmeric were very different in color from untreated products, while radiologically sterilized products showed a little difference. When comparing color and flavor in a 2D map, it was found at a glance that the radiologically sterilized product was close to the untreated product. Thia map can easily convince the merit of irradiation sterilization, and it was found to be effective for promoting risk communication. In the case of white pepper, the radiologically sterilized product showed more strong pungent than the superheated-steam sterilized product with statistically significant difference. However, not only the strength difference but also qualitative difference was perceived in flavor. (A.O.)

  18. A history of studies on safety of irradiated foods

    Miyahara, Makoto

    2003-01-01

    This report explained a history of studies on safety of irradiated foods in the United States. The army of USA had begun an experiment of irradiated foods in 1953. The toxic tests consisted of three phase, the phase I (1954 to 1959), phase II (1956 to 1965) and phase III (1971 to 1978). In the phase I, the short period toxic tests (90days) of 54 kinds of foods were carried out using high and low irradiation. The Swift and Company Laboratories reported detailed animal tests of 2685 albino rat, chickens and human. The animal tests showed many kinds of nutrition disorder, but the human test no problem. On phase II, 22 kinds of foods were tested for long period using rat, dog and mouse. Dog showed many kinds of symptom, for example, low birthrate, short life time, low growth rate, increasing spleen weight and thyroid disease. On phase III, two companies carried out the toxic test and Ralston Purina Company report is only data to be used now. Atomic Energy Commission (AEC) (1960 to 1970), Department of Commerce (1965 to 1976) and Department of Agriculture (1961 to 1966) studied safety of irradiated foods. Food and Drug Administration (FDA) determined that the irradiated foods belonged to under the category of food additive in 1958. FDA tests safety of irradiated foods using the determination tree and permitted many kinds of irradiated foods. (S.Y.)

  19. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo; Hayashi, Toru; Yasumoto, Kyoden.

    1990-01-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

  20. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo [Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries; Hayashi, Toru; Yasumoto, Kyoden

    1990-10-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author).

  1. Pathological study about two autopsy cases of bilateral irradiation pneumonitis induced by unilateral irradiation

    Yamauchi, Noriko; Tajima, Yo; Iio, Masaaki; Oshima, Takeo; Iino, Koichi.

    1978-01-01

    The first case is a 73-year-old man with left lung cancer. Seven days after completion of radiotherapy 7,000 rad, a chest roentgenogram showed diffuse bilateral pneumonia. The second case is a 61-year-old woman with right lung cancer and about one month after completion of radiotherapy 2,600 rad, a chest roentgenogram showed bilateral pneumonia. Pathological findings, all lobes of both lungs of these cases showed acute interstitial pneumonitis. The pathogenesis of irradiation pneumonitis is poorly understood. Several investigators thought that the pathogenesis of irradiation pneumonitis was caused by autoimmune mechanism, they carried out sero-pathological studies and demonstrated the bilateral pneumonia caused by unilateral irradiation. (author)

  2. Caramel fuel for research reactors: experience acquired in the fabrication, monitoring and irradiation of Osiris core

    Contenson, Ghislain de; Foulquier, Henri; Trotabas, Maria; Vignesoult, Nicole; Cerles, J.-M.; Delafosse, Jacques.

    1981-06-01

    A plate type nuclear fuel (Caramel fuel) has been developed in France in the framework of the various activities pursued in the design, fabrication and development of nuclear fuels by the CEA. This fuel can be adapted to various different categories of water cooled reactor (power reactors, marine propulsion reactors, urbain heating reactors, research reactors). The successful work conducted in this field led the realization of a complete core and reloads for the high performance research reactor, Osiris, at Saclay. The existing highly enriched U-Al alloy fuel was replaced by a non-proliferating low enrichment (7%) caramel fuel. This new core has been operating successfully since january 1980. A brief description of Caramel and its main advantages is given. The way in which it is fabricated is described together with the quality controls to which it is subjected. The qualification program and the main results deduced from it are also presented. The program used to monitor its in-pile behavior is described. The essential purpose of this program is to ensure the high performance of the fuel under irradiation. The successful operation of Osiris, which terminated 11 irradiation cycles on the 21st of April 1981 confirmed the correctness of the decisions made and the excellent performance that could be achieved with these fuel elements under the severe conditions encountered in a high performance research reactor [fr

  3. Experimental study associated to irradiation of FBR structural material, (4)

    1976-01-01

    The study presents one of the bases to evaluate the results of the post-irradiation tests to conduct the thermal control tests related to the second JMTR irradiation (70M-61P) of the demestic austenitic stainless steels for the structural material of the FBR performed by Power Reactor and Nuclear Fuel Development Corporation. The thermal control specimens were given the temperature history which simulated that of the irradiation temperature in vacuum by the electrical furnance, and then the tensile, fatigue and Charpy impact tests were performed. The changes of the material properties caused by the thermal history were investigated. (auth.)

  4. Study on quality control of Chinese herb medicine irradiation

    Yang Dongqing; En Lihua; Deng Wenmin

    2010-01-01

    6-8 kGy γ-ray irradiation dosage treatment can reduce the bacteria, mildew effectively from 105 CFU/g to 102 CFU/g and eliminate the parasite in 4 kind of Chinese herb medicine, enhance their quality of sanitation observably. In the other hand, irradiation doesn't influence the medicinal component and therapy effect. Storage study has improved that the 4 kind of Chinese herb medicine treated by γ-ray irradiation can be preserved over one year in the room temperature with high quality of sanitation and steady medicinal component. (authors)

  5. Studies on apple preservation by 60 -gamma irradiation

    Wang Chuanyao; Jiang Mengyue; Gao Meixu

    1992-01-01

    Studies on '60'Co-gamma irradiation of Golden Delicious apple have been carried out. The results showed that the optimum irradiation dosage for stored apple was ranged from 0.3-0.5 k Gy, with this dosage, the contents of vitamin c and titratalbe acidity in these apples had no significant change compared with unirradiated apples. The respiratory rate and the amount of ethylene release were decreased after irradiation. The mortality of the verticillate pathogenic fungi was 97% at the dose of 0.5 k Gy

  6. Study on identification of irradiated food containing cellulose by ESR

    Wan Xiaojuan; Dou Daying; Xu Gang; Jiao Zheng; Wang Jia; Zheng Jianfei; Jiao Zheng; Wu Minghong; Ding Guoji

    2008-01-01

    The fast development and application of food irradiation technology signify the necessity and urgency to research on effective detection method for irradiated food. In this paper, we report a preliminary study in this area with dried chili powder, peanuts and strawberry seeds. The food samples were irradiated to 0.5, 1.0, 3.0, 5.0 and 10.0 kGy by 60 Co gamma rays. The relation between ESR intensity and irradiation dose, and correlation R 2 , were studied. The results showed that the ESR signal intensity is positively related with the dose. ESR intensity of the strawberry increased the slowest with the dose, and the chili powder had the most accurate calculation. Accurate dose-effect curves, however, require repeating tests and further studies are needed to verify the ESR results. (authors)

  7. Medical waste irradiation study. Final report

    Adler, R.J.; Stein, J. [North Star Research Corp., Albuquerque, NM (United States); Nygard, J. [Advance Bio-Control (United States)

    1998-07-25

    The North Star Research Corporation Medical Waste project is described in this report, with details of design, construction, operation, and results to date. The project began with preliminary design of the accelerator. The initial design was for a single accelerator chamber with a vacuum tube cavity driver built into the chamber itself, rather than using a commercial tube separate from the RF accelerator. The authors believed that this would provide more adjustability and permit better coupling to be obtained. They did not have sufficient success with that approach, and finally completed the project using a DC accelerator with a unique new scanning system to irradiate the waste.

  8. Ion irradiation studies of oxide ceramics

    Zinkle, S.J.

    1988-01-01

    This paper presents the initial results of an investigation of the depth-dependent microstructures of three oxide ceramics following ion implantation to moderate doses. The implantations were performed using ion species that occur as cations in the target material; for example, Mg + ions were used for MgO and MgAl 2 O 4 (spinel) irradiations. This minimized chemical effects associated with the implantation and allowed a more direct evaluation to be made of the effects of implanted ions on the microstructure. 11 refs., 14 figs

  9. Medical waste irradiation study. Final report

    Adler, R.J.; Stein, J.; Nygard, J.

    1998-01-01

    The North Star Research Corporation Medical Waste project is described in this report, with details of design, construction, operation, and results to date. The project began with preliminary design of the accelerator. The initial design was for a single accelerator chamber with a vacuum tube cavity driver built into the chamber itself, rather than using a commercial tube separate from the RF accelerator. The authors believed that this would provide more adjustability and permit better coupling to be obtained. They did not have sufficient success with that approach, and finally completed the project using a DC accelerator with a unique new scanning system to irradiate the waste

  10. Study on innocent irradiation treatment of Trichinella spiralis pork

    Zhao Guang; Guo Anxi; Xu Zhaomei

    1992-01-01

    The effects of 60 Co gamma rays on pork Trichinella spiralis and nutritional hygiene evaluation of irradiated Trichinella spiralis pork were studied by using animal infestation test and artificial gastric juice digestion method. The results showed that when mouse was infested by Trichinella spiralis pork irradiated with a dose of 0.04 kGy, the number of the second generation larvae and the parasitism in the muscle were reduced. 0.08 kGy irradiation could render the intestine Trichinella spiralis sterile. 0.1 kGy blocked the growth of Trichinella spiralis, which were excreted from the body four days after infestation. 0.2-0.8 kGy irradiation could severely block the growth of Trichinella spiralis, which were excreted completely from the body within forth-eight hours when irradiated with 7 kGy and 8 kGy, the Trichinella spiralis body was not found in the intestine within twenty-four hours. 0.3 kGy and 1 kGy irradiation had no harmful effect on nutrition and wholesomeness of Trichinella spiralis pork. Innocent irradiation treatment of Trichinella spiralis pork is practicable, and the lowest dose should be 0.3 kGy

  11. Histopathologic study on irradiated human developing teeth

    Takeda, Yasunori (Iwate Medical Coll., Morioka (Japan). School of Dentistry)

    1982-12-01

    The patient was a 7-year-old boy who had been suffering from Ewing's sarcoma originating in the mandible. Irradiation with 8000 rad of Linac was performed on the mandible prior to mandibulectomy. The results of the histopathologic examination of the teeth including resected material were as follows: 1. Although the tumor tissue was not found in the resected material, complete resoption of the medullar trabecular bone with fibrosis was noted in the area between the first molar region and the mandibular ramus. 2. The first and the second premolar teeth were in the early stage of root formation, and conglomerates of dysplastic dentin were formed in the proliferative zones. This dysplastic dentin was surrounded by loose fibrous connective tissues. 3. The dysplastic dentin showed low mineralization, embedded irregular arranged-fibrous tissue matrix and scattered various-sized lacunae containing a few tiny and pyknotic cells. 4. Irregularly arranged odontoblasts with a pyknotic appearance were found along the tubular dentin, but diffuse fibrosis occurred in the pulpal tissues. 5. The first molar tooth had completed its root formation. Various amounts of osteodentin were formed at the secondary dentin layer. Inner-resorption of dentin and fibrosis of the pulpal tissue were also found. These changes concerning the first molar tooth were also due to the effects of irradiation. 6. The second molar tooth was resorbed by tumor infiltration, and dysplastic dentin was on the resorbed surface of the dentin.

  12. Self-irradiation study of plutonium alloys

    Oudot, B.

    2005-02-01

    The plutonium is unstable and produces α or β decays depending on the isotope. These decays generate americium, uranium, helium and different kinds of structural defects. The effects of self-irradiation damage are observed at macroscopic scale, the mechanism occurs from atomic scale. In order to improve our understanding of the self-irradiation effects in PuGa alloys, a technique sensitive to the vacancies and vacancies clusters has been developed: the Positron Annihilation Spectroscopy (PAS). The swelling has been characterized by XRD at a microscopic scale and by dilatometry at a macroscopic scale. Swelling starts just after melting and reaches a saturation between 6 and 36 months depending on the degree of gallium homogeneity in the alloy. Swelling at saturation increases with the gallium content, but the absolute change in the cell parameters is constant during time. PAS showed that vacancies clusters develop immediately. Their concentration increase with time. A part of these clusters is stabilized by helium atoms and leads to the creation of bubbles, which contribution to swelling is negligible. The vacancies and vacancies clusters which are not stabilized by helium contribute to the swelling increase by mechanisms known for other materials. These mechanisms are based on a 'dislocation bias'. The presence of these dislocations can furthermore explain the low mean life time value of positrons at the saturation point. (author)

  13. Histopathological studies on the irradiated brain tumors

    Narita, Tadao

    1980-01-01

    Of 43 cases of irradiated brain tumor, histological findings showed extensive necrosis or disappearance of the neoplasm, considered to be attributable to radiation treatment, in 30 (70%). Extensive necrosis of the tumor in areas exposed to radiation was found in 16 treated cases (37.2%). The histopathology of massive necrosis was that of simple coagulative necrosis, sometimes with marked vascular alterations and extravasation of fibrinoid material into the necrotic tissue. Necrosis was almost always incomplete, and foci of residual tumors were found at the periphery of the tumors. The terminal picture in cases of massive necrosis was often that of widespread intra- and extracranial metastasis. Almost complete disappearance of the tumor was observed in some cases with subsequent diffuse degenerative changes in the brain parenchyma exposed to radiation. In 5 cases of irradiated tumors, autopsy findings suggested that the growth of the primary tumor might have been restricted. And in 5 cases tumor cytology revealed the marked presence of a large number of multinucleated, bizarre giant cells with evidence of degeneration in both the cytoplasm and the nucleus. Multifocal necrosis of the brain, with axonal swelling and sponginess of the tissue, was observed in two patients following combined radiation and antineoplastic chemotherapy. Diffuse loss and degeneration of nerve cells of the cerebral cortex in pseudo-laminar fashion was observed in 7 patients with or without bilateral necrosis of the globus pallidus. Histological findings revealed typical anoxic encephalopathy. (J.P.N.)

  14. Histopathological studies on the irradiated brain tumors

    Narita, T [Gunma Univ., Maebashi (Japan).School of Medicine

    1980-01-01

    Of 43 cases of irradiated brain tumor, histological findings showed extensive necrosis or disappearance of the neoplasm, considered to be attributable to radiation treatment, in 30 (70%). Extensive necrosis of the tumor in areas exposed to radiation was found in 16 treated cases (37.2%). The histopathology of massive necrosis was that of simple coagulative necrosis, sometimes with marked vascular alterations and extravasation of fibrinoid material into the necrotic tissue. Necrosis was almost always incomplete, and foci of residual tumors were found at the periphery of the tumors. The terminal picture in cases of massive necrosis was often that of widespread intra- and extracranial metastasis. Almost complete disappearance of the tumor was observed in some cases with subsequent diffuse degenerative changes in the brain parenchyma exposed to radiation. In 5 cases of irradiated tumors, autopsy findings suggested that the growth of the primary tumor might have been restricted. And in 5 cases tumor cytology revealed the marked presence of a large number of multinucleated, bizarre giant cells with evidence of degeneration in both the cytoplasm and the nucleus. Multifocal necrosis of the brain, with axonal swelling and sponginess of the tissue, was observed in two patients following combined radiation and antineoplastic chemotherapy. Diffuse loss and degeneration of nerve cells of the cerebral cortex in pseudo-laminar fashion was observed in 7 patients with or without bilateral necrosis of the globus pallidus. Histological findings revealed typical anoxic encephalopathy.

  15. Studies in mice fed a diet containing irradiated fish

    1979-01-01

    Three groups of mice were observed in utero and for eighty (80) weeks thereafter to study growth, food consumption, hematology, blood chemistry and survival with particular interest in carcinogenic potential. Group I received only Purina Mouse Chow, Group II received a diet composed of 45% non-irradiated fish and 55% Purina Mouse Chow, and Group III received a diet composed of 45% gamma irradiated fish and 55% Purina Mouse Chow. Differences observed in body weights between control and fish treated diets were due to the incorporation of fish into the diet and not the results of fish being treated with gamma irradiation. Differences observed in food consumption between control and fish treated diets were due to the incorporation of fish into the diet and not the result of fish being treated with gamma irradiation. No daily observations were made which could be attributed to the treatment of fish with gamma irradiation. No observations were made at any time interval for hematology which could be attributed to the treatment of fish with gamma irradiation. No observations were made at any time interval for clinical chemistry which could be attributed to the treatment of fish with gamma irradiation. Palpable mass data did not reveal any trends which could be related to the treatment of fish with gamma irradiation. Gross observations at necropsy were limited to spontaneously occurring lesions or artifacts of necropsy technique commonly associated with animals of this species and age. Organ weight data did not reveal any trends which could be related to the treatment of fish with gamma irradiation. Pathological findings were limited to spontaneously occurring lesions or artifacts of necropsy technique commonly associated with animals of this species and age. (orig.)

  16. Irradiation Embrittlement Monitoring Programs of RPV's in the Slovak Republic NPP's

    Kupca, Ludovik

    2006-01-01

    Four types of surveillance programs were (are) realized in Slovak NPP's: 'Standard Surveillance Specimen Program' (SSSP) was finished in Jaslovske Bohunice V-2 Nuclear Power Plant (NPP) Units 3 and 4, 'Extended Surveillance Specimen Program' (ESSP), was prepared for Jaslovske Bohunice NPP V-2 with aim to validate the SSSP results, For the Mochovce NPP Unit 1 and 2 was prepared completely new surveillance program 'Modern Surveillance Specimen Program' (MSSP), based on the philosophy that the results of MSSP must be available during all NPP service life, For the Bohunice V-1 NPP was finished 'New Surveillance Specimen Program' (NSSP) coordinated by IAEA, which gave arguments for prolongation of service life these units for minimum 20 years, New Advanced Surveillance Specimen Program (ASSP) for Bohunice V-2 NPP (units 3 and 4) and Mochovce NPP (units 1, 2) is approved now. ASSP is dealing with the irradiation embrittlement of heat affected zone (HAZ) and RPV's austenitic cladding, which were not evaluated till this time in surveillance programs. SSSP started in 1979 and was finished in 1990. ESSP program started in 1995 and will be finished in 2007, was prepared with aim of: increasing of neutron fluence measurement accuracy, substantial improvement the irradiation temperature measurement, fixed orientation of samples to the centre of the reactor core, minimum differences of neutron dose for all the Charpy-V notch and COD specimens, the dose rate effect evaluation. In the year 1996 was started the new surveillance specimen program for the Mochovce RPV's unit-1 and 2, based on the fundamental postulate - to provide the irradiation embrittlement monitoring till the end of units operation. The 'New Surveillance Specimen Program' (NSSP) prepared in the year 1999 for the Bohunice V-1 NPP was finished in the year 2004. Main goal of this program was to evaluate the weld material properties degradation due to the irradiation and recovery efficiency by annealing too. The

  17. Studies on Post-Irradiation DNA Degradation in Micrococcus Radiodurans, Strain RII51

    Auda, H.; Emborg, C.

    1973-01-01

    The influence of irradiation condition on post-irradiation DNA degradation was studied in a radiation resistant mutant of M. radiodurans, strain ${\\rm R}_{{\\rm II}}5$. After irradiation with 1 Mrad or higher more DNA is degraded in cells irradiated in wet condition than in cells irradiated with t...

  18. Study of LAXS Profile of Hemoglobin from Irradiated Blood

    Selim, N.S.; Desouky, O.S.; Elshemey, W.M.

    2006-01-01

    The present work aims to move a step forward towards a deeper understanding of the scattering of x-ray, from lyophilized biological samples. Comparative study has been performed using low angle x-ray scattering (LAXS) and UV-visible spectrophotometry for monitoring the dose response characteristics of the hemoglobin molecule of irradiated blood. Blood samples were exposed to gamma rays, at doses ranging from 5 up to 100 Gy. Diluted hemoglobin solution was scanned in the UV-visible range (200-700 nm), and lyophilized hemoglobin was prepared for LAXS measurement. The radiation-induced changes in the hemoglobin structure have been evaluated. The LAXS profile of hemoglobin molecule is characterized by the presence of 2 peaks in the forward direction of scattering. These peaks were found to be sensitive to the variations in the molecular structure of a given sample. The obtained results suggest that the 1st peak, recorded at 4.65O (equivalent to momentum transfer, x= 0.526 nm-1), is sensitive to the tertiary and quaternary structure of the globin part, while the major peak, recorded at 10.5O (equivalent to momentum transfer, x= 1.189 nm-1), appeared to be related to its primary and secondary structure

  19. The preliminary study on peculiar flavor from irradiated dried duck

    Li Zongju; Chen Zongdao; Xu Denyi

    1992-01-01

    Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R f =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck

  20. The preliminary study on peculiar flavor from irradiated dried duck

    Zongju, Li; Zongdao, Chen; Denyi, Xu [Southwest Agricultural Univ., Chongqing, SC (China)

    1992-11-01

    Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R[sub f] =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck.

  1. Study of the stability of the tragacanto rubber irradiated

    Rodriguez, M.; Romero, M.; Montes de Oca, N.

    2001-01-01

    Presently work was studied the processing by radiations of the tragacanto rubber powdered, with ends of achieving its sterilization. For the irradiation, the envelopes were placed in aluminum containers to reason of an envelope for container. The material underwent analysis of its viscosity and microbiological tests. They got ready solutions, according to the British pharmacopoeia, starting from the material irradiated with dose of D0-0, D1-5, D2-7.5, and D3-10 kGy. The smaller than the applied doses (5kGy) it produced a variation of 72% in the viscosity of the solutions, in comparison with the rubber without irradiating. They were carried out tests of sterility to the material irradiated with inferior dose of 5 kGy, being contaminated in all the cases

  2. Study on process control and acceptability of irradiated seasonings

    Chen Qixun; Xu Peishu; Chen Hao; Chen Lihua; Dong Shaobin

    1993-01-01

    This paper studied the process control and quality control of irradiated seasonings for commercial purposes, market test and consumers' acceptability. The results showed that the rate of relative deviation of dose was less than 2 and the uniformity was better than 1.31 and the number of microbes decreased by 3-4 orders of magnitude after treatment with 8 kGy. No pathogenic bacteria were discovered and sensory evaluation as well as quality analysis were not changed. 110 tons of irradiated seasonings have been supplied to domestic markets and stores since 1990. The statistic data of 2045 consumers investigated showed that 67% of consumers heard about food irradiation. 72% of persons and 67% of families were willing to buy irradiated seasonings. (author)

  3. Physicochemical Studies On Irradiated Triticale Seeds

    Hammad, Z.H.

    2012-01-01

    Triticale grains had slightly lower contents of fats (2.09%), proteins (13.05%), moisture (10.51%), than those of wheat (2.74, 13.68 and 10.94%) respectively. While the ash and total carbohydrate are higher in triticale grains (1.72% and 83.14%) than those of wheat grains (1.51% and 82.07%),. Wheat flour had higher contents of proteins (11.30%), carbohydrates (86.37%) than those of triticale (9.3% and 85.45% respectively). While triticale flour had higher contents of ash (1.04%), fats (1.93%), crude fiber (2.28%) than those of wheat flour (0.58%, 0.90% and 0.85%, respectively). Slight differences were found between different estimated parameters in irradiated grains (2.5, 5, 7.5 kGy) before and after storage for 6 months. The farinogram parameters of the flours with the different levels of the triticale flour, water absorption values decreased from 61.51 to 59.1% for triticale and flour blend. The maximum resistance (Bu) of the blend contained 10% triticale flour and 90% wheat flour was 665 and decreased by increasing the triticale flour ratio in the blends to 20% then the maximum resistance increased to 900. The extensibility (mm) value was increased from 105 at 10% triticale flour to 130 at 20% triticale flour then decreased to 95 at 40% triticale flour. γ-irradiation of different blends caused an increase in extensibility value. The general appearance, crust color and taste of the bread (10% triticale and 90% wheat) were given very good score.

  4. Wholesomeness studies in the International Food Irradiation Project

    Elias, P.S.

    1980-01-01

    Despite more than 25 years history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and it is required to carry out scientific investigations to reassure the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subject to the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans. (Kitajima, A.)

  5. Study of boron carbide evolution under neutron irradiation

    Simeone, D.

    1999-01-01

    Owing to its high neutron efficiency, boron carbide (B 4 C) is used as a neutron absorber in control rods of nuclear plants. Its behaviour under irradiation has been extensively studied for many years. It now seems clear that brittleness of the material induced by the 10 B(n,α) 7 Li capture reaction is due to penny shaped helium bubbles associated to a high strain field around them. However, no model explains the behaviour of the material under neutron irradiation. In order to build such a model, this work uses different techniques: nuclear microprobe X-ray diffraction profile analysis and Raman and Nuclear Magnetic Resonance Spectroscopy to present an evolution model of B 4 C under neutron irradiation. The use of nuclear reactions produced by a nuclear microprobe such as the 7 Li(p,p'γ) 7 Li reaction, allows to measure lithium profile in B 4 C pellets irradiated either in Pressurised Water Reactors or in Fast Breeder Reactors. Examining such profiles enables us to describe the migration of lithium atoms out of B 4 C materials under neutron irradiation. The analysis of X-ray diffraction profiles of irradiated B 4 C samples allows us to quantify the concentrations of helium bubbles as well as the strain fields around such bubbles.Furthermore Raman spectroscopy studies of different B 4 C samples lead us to propose that under neutron irradiation. the CBC linear chain disappears. Such a vanishing of this CBC chain. validated by NMR analysis, may explain the penny shaped of helium bubbles inside irradiated B 4 C. (author)

  6. Effect of gamma irradiation on nylon 6 films : swelling study

    Singh, L.P.; Chaudhuri, N.K.

    1980-01-01

    This paper reports on swelling studies of γ-irradiated nylon 6 films undertaken to investigate the effects of γ-irradiation in finer details. Benzyl alcohol has been used as the swelling agent. The kinetics of weight swelling of γ-irradiated nylon 6 films in benzyl alcohol was studied at different irradiation doses in the range 0 - 28.8 Mrad. It is observed that with increasing irradiation dose upto 14.4 Mrad the swelling, and hence the diffusion process are retarded; moreover, the sigmoidal nature of the percentage weight swelling vs (time)sup(1/2) plot is augmented. Above this critical dose the swelling and diffusion processes are accelerated. Besides, the sigmoidal behaviour recedes and is converted into linear behaviour at 28.8 Mrad. This behaviour indicates that a relaxation-controlled non-Fickian diffusion process is at work below 28.8 Mrad while at 28.8 Mrad a Fickian process is established. A significant effect on the equilibrium swelling in benzyl alcohol is observed. The plot of equilibrium weight swelling vs irradiation dose at 23deg C shows an initial decrease of swelling upto 3.6 Mrad at which swelling starts decreasing at accelerated rate in the dose range 3.6 - 7.6 Mrad. The rate slows down appreciably between 7.00 and 14.4 Mrad, above which there is a rapid fall. The results are correlated with scission and crosslinking processes through relative viscosity determination of formic acid solutions of the irradiated samples. It is established by combining viscosity data with kinetics and equilibrium swelling data that, besides scission, crosslinking processes are also at work in nylon 6 in the irradiation dose range 0 - 3.6 Mrad. It has been possible to bring out this point because the swelling technique seems to be preferentially sensitive towards crosslinking. (author)

  7. An irradiation facility with a horizontal beam for radiobiological studies

    Czub, J.; Adamus, T.; Banas, D.

    2006-01-01

    A facility with a horizontal beam for radiobiological experiments with heavy ions has been designed and constructed at the Heavy Ion Laboratory in Warsaw University. The facility is optimal to investigate the radiobiological effects of charged heavy particles on a cellular or molecular level as the plateau of the Bragg curve as well as in the Bragg peak. The passive beam spread out by a thin scattering foil provides a homogeneous irradiation field over an area of at least 1 x 1 cm 2 . For in vitro irradiation of biological samples the passive beam spreading combined with the x - y mechanical scanning of the irradiated sample was found to be an optimum solution. Using x - y step motor, the homogenous beam of ions with the energy loss range in the cells varied from 1 MeV/μm to 200 keV/μm is able to cover a 6 cm in diameter Petri dish that holds the biological samples. Moreover on-line fluence monitoring based on single-particle counting is performed to determine the dose absorbed by cells. Data acquisition system for dosimetry and ion monitoring based on a personal computer is described. (author)

  8. Study on neutron irradiation behavior of beryllium as neutron multiplier

    Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

  9. Study on the irradiation decontamination of traditional Chinese medicines

    Wang, B.; Shi, S.; Li, B.; Wang, G.

    2005-01-01

    Traditional Chinese Medicines (TCMs) are natural products prepared from plants, minerals and animals, it is easy for contamination by microorganisms to occur; thus causing problems in complying with the requirements laid down for passing microbial limit tests. We selected some kinds of TCMs, including unprocessed materia medica, traditional Chinese patent medicine (TCPMs) and chemical constituents for irradiation by 60 Co gamma ray and investigating the results in terms of microbiology, chemistry, pharmacology and toxicology. We found no evidence of changes in most of the tested items, which indicates that the irradiation method could be employed for decontamination of TCMs. However, some chemical constituents of unprocessed materia medica, such as gentiopicrin in Radix Gentianae Macrophyllae and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside in Radix Polygoni Multiflori, decomposed when these crude materials were irradiated with dose of 5kGy. Further study revealed that although the medicinal were altered by irradiation, the monomers of some of these chemical constituents were not affected. In addition to investigation of the items described above, the doses of irradiation were selected experimentally to ensure that, after irradiation, the TCMs passed the microbial limit tests described in the Chinese Pharmacopoeia. The lowest possible doses were used in order to avoid any impairment of the quality and clinical efficacy of the effective ingredients of the TCMs. (author)

  10. Analysis of the irradiation data for A302B and A533B correlation monitor materials

    Wang, J.A.

    1996-04-01

    The results of Charpy V-notch impact tests for A302B and A533B-1 Correlation Monitor Materials (CMM) listed in the surveillance power reactor data base (PR-EDB) and material test reactor data base (TR-EDB) are analyzed. The shift of the transition temperature at 30 ft-lb (T 30 ) is considered as the primary measure of radiation embrittlement in this report. The hyperbolic tangent fitting model and uncertainty of the fitting parameters for Charpy impact tests are presented in this report. For the surveillance CMM data, the transition temperature shifts at 30 ft-lb (ΔT 30 ) generally follow the predictions provided by Revision 2 of Regulatory Guide 1.99 (R.G. 1.99). Difference in capsule temperatures is a likely explanation for large deviations from R.G. 1.99 predictions. Deviations from the R.G. 1.99 predictions are correlated to similar deviations for the accompanying materials in the same capsules, but large random fluctuations prevent precise quantitative determination. Significant scatter is noted in the surveillance data, some of which may be attributed to variations from one specimen set to another, or inherent in Charpy V-notch testing. The major contributions to the uncertainty of the R.G. 1.99 prediction model, and the overall data scatter are from mechanical test results, chemical analysis, irradiation environments, fluence evaluation, and inhomogeneous material properties. Thus in order to improve the prediction model, control of the above-mentioned error sources needs to be improved. In general the embrittlement behavior of both the A302B and A533B-1 plate materials is similar. There is evidence for a fluence-rate effect in the CMM data irradiated in test reactors; thus its implication on power reactor surveillance programs deserves special attention

  11. Molecular genetic studies on irradiated wheat plants

    Saleh, O.M.

    2002-01-01

    Composite genotype(octamer hybrid) was obtained from crossing among eight Egyptian hexaploid wheat cultivars differing in their tolerance to drought stress to produce a genotype, which can economize on the irrigation water requirements or can tolerate drought stress. Gamma irradiation with 10-Krad was used to induce mutations, which could improve drought tolerance for this composite. From eight Egyptian wheat cultivars, two were chosen as drought tolerant and drought sensitive genotypes (G-160 and Sk-61, respectively. They were evaluated along with their F1 and F2 for their relative drought tolerance for some yield-related traits. Bulked segregating analysis developed some RAPD and SSR markers with different primers, which were considered as molecular for drought tolerance in wheat. Hal 2-like gene was introduced into Egyptian wheat cultivar G-164 via micro projectile bombardment. Two putative transgenic plants were successfully detected by leaf painting with the herbicide basta. PCR/ Southern blotting analysis indicated the presence of both/either bar and/or Hal 2-like genes in the genomic background of the two transgenic plants

  12. Overview of cobalt-60 external irradiation study

    Stitzel, K.; Shifrine, M.; Wilson, F.

    1980-01-01

    Work this year has continued to define the immunohematological effects of radiation exposure in Davis beagles over 50 days of age. One case of myeloproliferative disease occurred in one of the animals exposed to 4 R/day, and cases of bone marrow aplasia occurred in the 11 R/day, 4 R/day, and 2 R/day groups. Use of bone marrow transplantation has revealed a profound difference in the mechanism of aplasia induction in dogs which are susceptible to low doses (less than 2000 R exposure at 11 R/day) and dogs which are able to survive in the radiation field for long periods (greater than 3000 R at 11 R/day or 1800 R at 2 R/day). In the latter animals damage occurs to the hematopoietic stromal microenvironment or some other regulatory mechanism which directs the differentiation of the hematopoietic stem cells into the specific end cell pathways (i.e. thrombocytes, red cells neutrophils). In the animals which develop radiation disease after low total exposure, the damage appears to be to the hematopoietic stem cells themselves. This implies that in some animals the stem cells are resistant to massive doses of continuous whole body irradiation, relative to the dose rate

  13. Studies on gamma irradiated rubber materials

    Lungu, I. B.; Stelescu, M. D.; Cutrubinis, M.

    2018-01-01

    Due to the increase in use and production of polymer materials, there is a constant pressure of finding a solution to more environmental friendly composites. Beside the constant effort of recycling used materials, it seems more appropriate to manufacture and use biodegradable and renewable row materials. Natural polymers like starch, cellulose, lignin etc are ideal for preparing biodegradable composites. Some of the dynamic markets that use polymer materials are the food and pharmaceutical industries. Because of their desinfastation and sometimes sterility requirements, different treatment processes are applied, one of it being radiation treatment. The scope of this paper is to analyze the mechanical behaviour of rubber based materials irradiated with gamma rays at four medium doses, 30.1 kGy, 60.6 kGy, 91 kGy and 121.8 kGy. The objectives are the following: to identify the optimum radiation dose in order to obtain a good mechanical behaviour and to identify the mechanical behaviour of the material when adding different quantities of natural filler (20 phr, 60 phr and 100 phr).

  14. An ultrastructural and irradiation study of diffuse and localised kinetochore

    Bokhari, F.S.

    1979-05-01

    An electron microscope study of plant types Luzula nivea and Cyperus eragrostis with diffuse kinetochores and Crepis neglecta with localised kinetochore showed that Luzula has a rather different kinetochore organisation from Cyperus, with features approaching the localised type of Crepis. These studies included an examination of the ultrastructure of the kinetochore at metaphase at low magnification in control and irradiated material of Luzula; the chromosomal ultrastructure at high magnification at interphase and all stages of mitosis in Luzula, Cyperus and Crepis; and the ultrastructure of the nucleolus in Luzula, Cyperus and Crepis. Light microscopic studies were also performed showing the effects of irradiation on first mitotic division in Cyperus, Luzula and Crepis, mitotic aberrations in Cyperus and Crepis and meiosis in Cyperus. Finally, the survival with the diffuse as opposed to the localised kinetochore in M 1 and M 2 generations following seed irradiation was studied. (U.K.)

  15. Structural and functional changes in the intenstine of irradiated and hypothermic irradiated rats : a scanning and transmission electron microscopic study

    Chaudhuri, S.; Chaudhuri, Swapna; Roy, Bijon

    1982-01-01

    Severe destructive changes in the intestine of rats following whole body exposure to gamma rays (832 rads) were observed by light microscope, scanning and transmission electron microscope studies. Hypothermia (15deg C rectal temperature) induced prior to irradiation protected the intestinal mucosa from destruction. A simultaneous study showed that glucose absorption decreased significantly in irradiated rats, whereas it was increased in hypothermic irradiated animals. (author)

  16. Prospective study of nutritional support during pelvic irradiation

    Kinsella, T.J.; Malcolm, A.W.; Bothe, A. Jr.; Valerio, D.; Blackburn, G.L.

    1981-01-01

    A prospective study of nutritional support during pelvic irradiation was carried out in 32 patients with a primary pelvic malignancy and prior weight loss. Both curative and palliative patients were eligible for the study. Seventeen patients were randomized to receive intravenous hyperalimentation (IVH) and fifteen patients served as controls who were maintained on their regular diet. Patients were stratified by percent body weight loss. Tolerance to therapy was assessed by evaluation of functional status and by using nutritional parameters of body weight change, change in serum protein levels, and response to delayed hypersensitivity skin tests. The curative IVH group tolerated therapy well by both functional and nutritional measurements. All curative IVH patients completed the planned radiation therapy without a treatment break and were fully active following treatment. Patients gained an average of 4.0 kg body weight during irradiation, which was significantly different from the curative control patients. They demonstrated a significant increase in serum transferrin reflecting an improvement in visceral protein. In addition, all showed a positive response to delayed hypersensitivity skin tests at the completion of irradiation. The palliative IVH patients often did poorly because of progression of disease and demonstrated only an elevation of serum transferrin during treatment. The results in the curative IVH group suggest a potential adjunctive role for intravenous hyperalimentation in the malnourished cancer patient undergoing pelvic irradiation. Clearly, further study of nutritional support during pelvic irradiation is needed using curative patients with a single tumor type and significant prior weight loss

  17. Spectroscopic studies of irradiated glasses: Application in nuclear dosimetry

    Farah, Khaled

    2010-01-01

    The present work aims to study the effects of ionizing radiation on silicate glasses in order to develop a new dosimetry system simple, precise, stable and inexpensive. Indeed, changes in mechanical properties, optical and paramagnetic glasses when subjected to ionizing radiation. The prediction of long-term behavior, physical aging under irradiation, the glass is paramount. many studies have brought many ways to avoid obscuring glass windows used in nuclear reactors or hot cells and optical devices. Recently, much work has concentrated on the application of the color induced by irradiation for developing a recyclable glass in the glass industry is of great interest economically and environmentally.

  18. Study of irradiation defects in GaAs

    Loualiche, S.

    1982-11-01

    Characterization techniques: C(V) differential capacity, DLTS deep level transient spectroscopy, DDLTS double deep level transient spectroscopy and DLOS deep level optical spectroscopy are studied and theoretical and experimental fundamentals are re-examined. In particular the centres created by ionic or electronic bombardment of p-type GaAs. New quantitative theoretical bases for the C(V) method are obtained. Study of the optical properties of traps due to irradiation using DLOS. The nature of irradiation defects are discussed [fr

  19. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

  20. EPR study on tomatoes before and after gamma-irradiation

    Aleksieva, K.; Georgieva, L.; Tzvetkova, E.; Yordanov, N.D.

    2009-01-01

    The results from the EPR studies on fresh, air-dried and lyophilized tomato samples before and after gamma-irradiation are reported. Before irradiation fresh and air-dried tomatoes exhibit one singlet EPR line characterized with common g-factor of 2.0048±0.0005, whereas freeze-dried tomato does not show any EPR spectrum. After irradiation, a typical 'cellulose-like' triplet EPR spectrum appears in all samples, attributed to cellulose free radicals, generated by gamma-irradiation. It consists of intense central line with g=2.0048±0.0005 and two weak satellite lines separated ca. 3 mT left and right of it. In air-dried and lyophilized tomatoes the 'cellulose-like' EPR spectrum is superimposed by an additional partly resolved carbohydrate spectrum. Fading measurements of the radiation-induced EPR signals indicate that the intensity of the EPR spectra of air-dried and freeze-dried tomato are reduced to about 50% after 50 days, whereas those of fresh irradiated tomatoes kept at 4 o C fade completely in 15 days. The reported results unambiguously show that the presence of two satellite lines in the EPR 'cellulose-like' spectra of tomato samples can be used for identification of radiation processing.

  1. Monte Carlo simulations and dosimetric studies of an irradiation facility

    Belchior, A. [Instituto Tecnologico e Nuclear, Estrada nacional no. 10, Apartado 21, 2686-953 Sacavem (Portugal)], E-mail: anabelchior@itn.pt; Botelho, M.L; Vaz, P. [Instituto Tecnologico e Nuclear, Estrada nacional no. 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2007-09-21

    There is an increasing utilization of ionizing radiation for industrial applications. Additionally, the radiation technology offers a variety of advantages in areas, such as sterilization and food preservation. For these applications, dosimetric tests are of crucial importance in order to assess the dose distribution throughout the sample being irradiated. The use of Monte Carlo methods and computational tools in support of the assessment of the dose distributions in irradiation facilities can prove to be economically effective, representing savings in the utilization of dosemeters, among other benefits. One of the purposes of this study is the development of a Monte Carlo simulation, using a state-of-the-art computational tool-MCNPX-in order to determine the dose distribution inside an irradiation facility of Cobalt 60. This irradiation facility is currently in operation at the ITN campus and will feature an automation and robotics component, which will allow its remote utilization by an external user, under REEQ/996/BIO/2005 project. The detailed geometrical description of the irradiation facility has been implemented in MCNPX, which features an accurate and full simulation of the electron-photon processes involved. The validation of the simulation results obtained was performed by chemical dosimetry methods, namely a Fricke solution. The Fricke dosimeter is a standard dosimeter and is widely used in radiation processing for calibration purposes.

  2. The ageing kidney: biochemical and morphological study after irradiation

    Franciolini, F.; Becciolini, A.; Torcini, G.; Lanini, A.

    1982-01-01

    The behaviour of some activities of the kidney was studied both in young-adult and in adult rats exposed to an 8-Gy dose of γ-rays and killed at various intervals after irradiation (both in the morning and in the evening). Brush border and lysosomal enzymes did not show marked differences among control rats of the same age even if adult animals showed levels of maltase, alkaline phosphatase and LAP activities higher than the young-adult group. Moreover, irradiation did not induce typical modifications of the same enzyme activities in young-adult and adult rats. Adult animals showed a reduction in the brush border enzyme activities at 120 hours after irradiation while, at the same interval, lysosomal activities underwent an increase both in young and in adult animals. (orig.) [de

  3. Experimental studies on the effect of perfluorochemicals in tumor irradiation

    Shinoda, Jun; Iwai, Tomohiko; Hattori, Tatsuaki; Kondo, Hiroaki; Sakai, Noboru; Yamada, Hiroshi

    1984-01-01

    The effects of radiation therapy with Fluosol-DA on rat mammary tumors were studied. The tissue oxygen tension values of tumors in breathing mixed gas (5% carbon dioxide and 95% oxygen) with Fluosol-DA (25 ml/kg, i.v.) were significantly higher than those in room air without Fluosol-DA. The rats were divided into three groups: Group I received Fluosol-DA but no irradiation, Group II was treated with 1000 rads of irradiation using 60 Co without Fluosol-DA in room air and Group III received the same irradiation and Fluosol-DA in breathig mixed gas. In the latter group we observed a prolongation of the survival time and suppression of the tumor growth. (author)

  4. Autonomous monitoring unit, signs and registration for Cobalt-60 irradiator safety system

    Baldaconi, Ricardo H.; Costa, Fabio E. da, E-mail: ricardohovacker@hotmail.com, E-mail: fecosta@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Cobalt-60 irradiator of IPEN / CNEN, a category IV facility, has a security system for inter locking doors or exposure of radioactive sources made simultaneously by a programmable logic controller (PLC) model S7- 200 from Siemens and a relay logic. From a set of information, the both systems work together opening doors or exposing the sources. All incoming and outgoing information are sent serially via EIA232 communication to a personal computer with Windows® platform for a supervisory program which provides besides a monitoring the entire process by a synoptic table on the computer screen, also keeps records of all events on the computer's hard drive. The electronic management has proven to be efficient and has not produced any failure that had compromised the safety. The PLC along with the relay logic has always taken the right decisions ensuring proper radiation protection of operators and the integrity of radioactive sources, but it presented over the years of operation (beginning in 2004) less than a dozen flaws in system event log. The deficiency was found between the process of sending events via serial communication (EIA232) to the supervisory program. When failure occurs in a very short time, the PLC always took the right decision, but the registration process that had to go through the Windows® timeshare lost the information. This work aimed to build a standalone electronics connect the inputs and outputs of the security system, fully optocoupled to avoid any interference to the security system. It records each event on a memory card, waits for the right decision of the security system and in case of an incorrect decision an independent alarm notifies its own synoptic picture, and sends a text message to a group of defined cell phones. The circuit uses two microcontrollers called 'main' and 'secondary'. The main is responsible for the control and monitoring of peripheral inputs and outputs of the security system. The main is

  5. Autonomous monitoring unit, signs and registration for Cobalt-60 irradiator safety system

    Baldaconi, Ricardo H.; Costa, Fabio E. da

    2015-01-01

    The Cobalt-60 irradiator of IPEN / CNEN, a category IV facility, has a security system for inter locking doors or exposure of radioactive sources made simultaneously by a programmable logic controller (PLC) model S7- 200 from Siemens and a relay logic. From a set of information, the both systems work together opening doors or exposing the sources. All incoming and outgoing information are sent serially via EIA232 communication to a personal computer with Windows® platform for a supervisory program which provides besides a monitoring the entire process by a synoptic table on the computer screen, also keeps records of all events on the computer's hard drive. The electronic management has proven to be efficient and has not produced any failure that had compromised the safety. The PLC along with the relay logic has always taken the right decisions ensuring proper radiation protection of operators and the integrity of radioactive sources, but it presented over the years of operation (beginning in 2004) less than a dozen flaws in system event log. The deficiency was found between the process of sending events via serial communication (EIA232) to the supervisory program. When failure occurs in a very short time, the PLC always took the right decision, but the registration process that had to go through the Windows® timeshare lost the information. This work aimed to build a standalone electronics connect the inputs and outputs of the security system, fully optocoupled to avoid any interference to the security system. It records each event on a memory card, waits for the right decision of the security system and in case of an incorrect decision an independent alarm notifies its own synoptic picture, and sends a text message to a group of defined cell phones. The circuit uses two microcontrollers called 'main' and 'secondary'. The main is responsible for the control and monitoring of peripheral inputs and outputs of the security system. The main is

  6. Swedish studies on irradiation effect in structural materials

    Grounes, M; Myers, H P

    1962-12-15

    A brief description of work in hand at AB Atomenergi concerning the effects of neutron irradiation on structural materials is given. Some recent data is listed for the following pressure vessel steels 2103/R3 as used in the Aagesta reactor, SIS 142103, NO345, Fortiweld and weld metal OK 54 P. Zircaloy-2 has been studied regarding the combined effects of neutron irradiation and hydrogen content on tensile properties. The difficulties associated with determination of neutron dose and the correlation of damage with dose and neutron energy spectrum are discussed.

  7. Biochemical studies on irradiated onions, potatoes and mushrooms

    Matkovics, B.

    1985-01-01

    The activities of the antioxidant enzymes: superoxide dismutase, peroxidase and catalase and the quantitative values of some other important components of irradiated foodstuffs were studied. It was found that the activities of the examined antioxidant enzymes and the value of lipid peroxidation vary from species to species, but also depend on the variety within the species. Dynamic changes of the smaller molecules, lasting for various periods of time, can also be well observed following irradiation. This indicates that radiation treatment changes the physiological processes of the examined basic foodstuffs and give rise to new equilibria in these processes. (author)

  8. Biophysical studies of irradiated thymocytes. 1. Surface changes

    Sungurov, A Yu; Tokalov, S V; Petrov, Yu P; Sharlaeva, T M

    1985-08-15

    In order to study postirradiation changes in thymus lymphocyte surface, a number of biophysical analytical methods was used: the cell two-partition method, the physical adhesion method, fluorescence intensity and binding parameters of negatively charged ANS probe. Reduction of cell distribution factor in two-phase system and adhesion of thymocytes to cotton 1 hour after irradiation, as well as abrupt change in parameters of binding the probe in the interval of 3-4 hours after X-ray irradiation at the dose of 4 Gy are demonstrated.

  9. Solubility and IR studies of gamma-irradiated arabinoxylan

    Ebringerova, A.; Kacurakova, M.; Hromadkova, Z.; Pruzinec, J.

    1989-01-01

    The structural and solubility changes of a water-insoluble arabinoxylan with a low degree of branching was studied after γ-irradiation by IR spectroscopy and chemical analysis of the polysaccharide and its polymeric fractions. New functional groups like hydroperoxidic, carbonylic and endiolic ones were found after irradiation. The IR spectra shows that the structural changes involved by radiolytic treatment are reflected in the shape of the IR spectra of both polymeric fractions. The ratio of absorbance of the peaks at 1725 and 2920 cm -1 increased with radiation dose. (author) 17 refs.; 2 figs.; 2 tabs

  10. Swedish studies on irradiation effect in structural materials

    Grounes, M.; Myers, H.P.

    1962-12-01

    A brief description of work in hand at AB Atomenergi concerning the effects of neutron irradiation on structural materials is given. Some recent data is listed for the following pressure vessel steels 2103/R3 as used in the Aagesta reactor, SIS 142103, NO345, Fortiweld and weld metal OK 54 P. Zircaloy-2 has been studied regarding the combined effects of neutron irradiation and hydrogen content on tensile properties. The difficulties associated with determination of neutron dose and the correlation of damage with dose and neutron energy spectrum are discussed

  11. Thermogravimetric study of γ-irradiated lanthanum oxalate

    Nayak, H.; Bhatta, D.

    2000-01-01

    Thermogravimetric study of La 2 (C 2 O 4 ) 3 , exposed to different doses (5.0 - 50.0 x 10 -2 MGy) of γ-rays has been carried out. Marginal effect is observed at lower doses which is prominent at higher dose (5.0 x 10 -1 MGy). The radiolytic damaged entities, generated by irradiation favours the reaction by creating new potential nucleation centres in the lattice. The solid product, La 2 O 3 formed by irradiation also acts as a heterogeneous catalyst and brings out changes in the reactivity of the solid. (author)

  12. Moessbauer study of amorphous alloys irradiated with energetic heavy ions

    Kuzmann, E.; Spirov, I.N.

    1984-01-01

    The Moessbauer spectroscopy was applied to study radiation damages in amorphous alloys irradiated with 40 Ar (E=225 MeV) or 132 Xe (E=120 MeV) ions at room temperature. In the magnetically splitted Moessbauer spectra the dose-dependent decreases of the intensity of the 2nd and 5th lines as well as of the average hyperfine magnetic field were observed. The changes weAe also analysed using the hyperfine field distribution obtained from the spectra. The results are interpreted in terms of defect creation and structural changes of shortrange order of irradiated amorphoys alloys

  13. Fluorescence studies on gamma irradiated egg lecithin liposomal membrane

    Pandey, B.N.; Mishra, K.P.

    1998-01-01

    Alterations in structure and organization of sonicated EYL liposomal vesicular membrane after irradiation was investigated by DPH fluorescence probe which is a well known reporter for the environment of hydrophobic interior of membrane. Results of present study have demonstrated that loss of DPH fluorescence in liposomal membrane is linked to free radical mediated structural alterations possibly rigidization in the lipid bilayer

  14. Color formation study of irradiated polymers by electron beam

    Nardi, Daniela Teves

    2004-01-01

    Color formation on national and commercial polymers (polymethyl methacrylate, polystyrene and polycarbonate) irradiated by electrons beam was investigated by colorimetry (CIELab), electron spectroscopy resonance (ESR), photoacoustic infrared spectroscopy (FTIR-PAS) and differential exploratory calorimetry (DSC). The heat effect on colorimetric properties was investigated after heating (110 deg C for 1 hour) of irradiated polymers at 150 kGy. The rule of oxygen in colorimetric properties of irradiated polycarbonate was investigated in the air presence and absence (p = 10 -3 mmHg). The visual aspect did not agree with colorimetric parameters only for polycarbonate. Yellow color and darkness were induced by radiation for all studied polymers varying only the intensity and behavior in function of post-irradiation time and heating. Polymethyl methacrylate and polystyrene ESR spectra showed that radicals could be responsible by yellow color centers. Wherever, in polycarbonate, color centers were not due radical species. The nature of color centers for any studied polymer was not study by FTIR-PAS because there were no changes in FTIR-PAS spectra neither in function of dose nor heating. Polycarbonate was the most radiosensible and polystyrene was the most radioresistant of all studied polymers in concern of colorimetric properties. (author)

  15. Positron annihilation studies on proton irradiated nitrile rubber

    Ravi Chandran, T.S.G.; Lobo, Blaise; Ranganath, M.R.; Gopal, S.; Sreeramalu, V.

    1996-01-01

    NBR (Nitrile Butadiene Rubber) was irradiated with 4 MeV proton beam from a variable energy cyclotron (VEC) at VEC Centre, Calcutta, to a flux of 10 16 ions/cm 2 , in a vacuum of 10 -9 Torr and was studied through positron lifetime measurements

  16. Multigeneration feeding studies with an irradiated whole diet

    Aravindakshan, M.; Chaubey, R.C.; Chauhan, P.S.; Sundaram, K.

    1978-01-01

    Multigeneration feeding studies have been carried out to investigate the effects of long-term feeding of an irradiated whole diet in Wistar rats. The parent and the four successive generations were fed on a nutritionally adequate test diet exposed to either 0.2 or 2.5Mrad gamma radiation and the effects, if any, on various parameters of animal health were assessed. In addition to an unirradiated test control, a historical control group fed on stock laboratory rations was also employed for comparison. The test diet consisted of various components including some of the basic ingredients of human diet in India. Exposure of the test diet to 0.2 or 2.5Mrad did not affect the food efficiency ratio and there were no significant differences in the growth rates of animals fed on unirradiated or irradiated diets. Reproductive performance of the rats fed on irradiated or unirradiated diets belonging to the parent, first, second or third generations were also comparable. Mortality rates and reproductive function in relation to age were also not altered due to feeding of irradiated whole diets. The haematological profile and the serum enzymes of the animals of all the generations fed irradiated diets were within normal limits. Though some differences were observed in the relative weights of some organs, these effects were limited to a particular generation, did not show any definite pattern and could not be related to the ingestion of irradiated diets. First-generation rats examined at 100-104 weeks for gross pathological manifestations including tumour incidence also did not indicate any significant differences among groups. (author)

  17. Transportation and storage studies on irradiated Alphonso mangoes

    Farkas, J.; Dharkar, S.D.; Sreenivasan, A.

    1972-01-01

    Control as well as skin coated (6% ''Myvacet'') and/or irradiated (25 to 35 krad) mangoes were packed in baskets in dry paddy straw and shipped by rail. After a storage at a temperature of 25 to 32 0 C for a period of 8 days, the baskets were shipped back. After receipt in the laboratory the fruits were kept under observation for 5 more days and then scored for ripening and marketability as assessed by appearance, skin gloss and typical flavour. 100 per cent of fruits skin-coated and irradiated were marketable at the end of the experiment. None of the unirradiated control fruits were saleable by this time, while 66%, of the irradiated fruits were in acceptable condition. In further experiments one dozen mangoes each from control, irradiated and skin-coated and irradiated groups were wrapped individually in tissue paper and packed tightly in a plyweed box. This consignment was air-lifted from Bombay to Budapest, a distance of about 5600 kilometers. The time interval between irradiation and their receipt in Hungary was 4 days. The mangoes were assessed for their storage characteristics by various parameters that included physiological loss in weight, puncture resistance of the skin, pulp texture, carotenoids, acidity and organoleptic attributes, at various periods during storage. It was found that ripening and senescence are strikingly delayed in mangoes by skin-coating and radiation treatment. The treated mangoes retained their skin-resistance while the disappearance of chlorophyl and formation of carotenoids were substantially delayed. Weight loss in storage was lower and reduction of acidity and formation of sugars in the fruit flesh took place later. Organoleptically, the fruits subjected to the combination treatment were good. These studies point to the feasibility of the combination treatment in prolonging the shelf life of fruits significantly to enable their transport to distant countries. (F.G.)

  18. Assessment of population external irradiation doses with consideration of Rospotrebnadzor bodies equipment for monitoring of photon radiation dose

    I. P. Stamat

    2016-01-01

    Full Text Available This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc. which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

  19. Irradiation studies of non-human biota

    Shetty, N.J.; Chaubey, R.C.; Harini, B.P.; Jha, S.K.

    2014-01-01

    In this study the effect of gamma radiation on the Drosophila melanogaster, Eisenia fetida, Apis mellifera and Aedes aegypti were studied for its effect on factors like fecundity, hatchability, adult emergence, sex ratio, longevity, dose response curve and estimation of heat shock protein

  20. Neutron monitoring measurements for the CIT [Compact Ignition Tokamak] materials irradiations in the ATR I1 position

    Rogers, J.W.; Anderl, R.A.

    1989-12-01

    Measurements were performed to help characterize the neutron environments in which the Compact Ignition Tokamak (CIT) materials were irradiated. These materials were irradiated in a lead shield plug assembly at the ATR I1 position. Neutron monitor materials were placed in the capsules in proximity with the CIT specimens. The neutron monitors sensed the neutrons through reactions that have different neutron energy region responses. By measuring the radioactivity of the neutron monitors it was possible to determine the neutron fluence rates (n/cm 2 /sec) and fluences (n/cm 2 ) at the locations of the monitors. It was also possible to determine the axial and radial gradients of the neutron environments near the specimens. This report presents the results obtained from these measurements for both the CIT number-sign 1 (ORNL 64-2) and CIT number-sign 2 (ORNL 64-1) capsules. In general, ASTM methods and procedures were used in all neutron monitoring associated activities. 7 refs., 9 figs., 10 tabs

  1. Some conclusions of studies on irradiation of whole fish aboard fishing vessels

    Reinacher, E.; Ehlermann, D.A.E.

    1978-01-01

    Studies were conducted on irradiation of whole redfish and haddock (at 100 krad) and subsequent storage of the irradiated fish for up to approx. 30 days in ice. The fish were organoleptically evaluated at intervals during storage. The results show no significant difference in organoleptic quality between irradiated and non-irradiated samples during storage for [de

  2. EPR study on non- and gamma-irradiated herbal pills

    Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N.D.

    2011-01-01

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  3. EPR study on non- and gamma-irradiated herbal pills

    Aleksieva, K., E-mail: katerina_bas@abv.b [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Lagunov, O. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Yordanov, N.D. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2011-06-15

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048{+-}0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  4. Experimental study on active specific immunotherapy modified with irradiation

    Imanaka, Kazufumi; Ogawa, Yasuhiro; Gose, Kyuhei; Imajo, Yoshinari; Kumura, Shuji

    1982-01-01

    We have already reported that the effectiveness of active specific immunotherapy using irradiated tumor cells and infiltrating mononuclear cells which were separated from the topical tumor tissue 7 days after irradiation of 2,000 rad in experimental study. The present study was designed to investigate the effect of non-specific immunopotentiator PS-K combined with active specific immunotherapy. Female C3H/He mice aged 12 weeks were inoculated 4 x 10 6 MM 46 tumor cells in the right hind paws and received local electron irradiation with the dose of 3,000 rad on the 5th day after irradiation. Active specific immunotherapy was performed on the 12th day, and daily dose of 200 mg/kg of PS-K was injected intraperitoneally from the 6th day to the 10th day. The inhibition of the tumor growth and the elongation of survival period were noted in the group which received active specific immunotherapy combined with non-specific immunopotentiator, PS-K compared with the active specific immunotherapy alone. (author)

  5. Damage studies on tungsten due to helium ion irradiation

    Dutta, N.J.; Buzarbaruah, N.; Mohanty, S.R.

    2014-01-01

    Highlights: • Used plasma focus helium ion source to study radiation induced damage on tungsten. • Surface analyses confirm formation of micro-crack, bubbles, blisters, pinholes, etc. • XRD patterns confirm development of compressive stress due to thermal load. • Reduction in hardness value is observed in the case of exposed sample. - Abstract: Energetic and high fluence helium ions emitted in a plasma focus device have been used successfully to study the radiation induced damage on tungsten. The reference and irradiated samples were characterized by optical microscopy, field emission scanning electron microscopy, X-ray diffraction and by hardness testers. The micrographs of the irradiated samples at lower magnification show uniform mesh of cracks of micrometer width. However at higher magnification, various types of crystalline defects such as voids, pinholes, bubbles, blisters and microcracks are distinctly noticed. The prominent peaks in X-ray diffraction spectrum of irradiated samples are seen shifted toward higher Bragg angles, thus indicating accumulation of compressive stress due to the heat load delivered by helium ions. A marginal reduction in hardness of the irradiated sample is also noticed

  6. White spot syndrome virus inactivation study by using gamma irradiation

    Heidareh, Marzieh; Sedeh, Farahnaz Motamedi; Soltani, Mehdi; Rajabifar, Saeed; Afsharnasab, Mohammad; Dashtiannasab, Aghil

    2014-09-01

    The present study was conducted to investigate the effect of gamma irradiation on white spot syndrome virus (WSSV). White spot syndrome virus is a pathogen of major economic importance in cultured penaeid shrimp industries. White spot disease can cause mortalities reaching 100% within 3-10 days of gross signs appearing. During the period of culture, immunostimulant agents and vaccines may provide potential methods to protect shrimps from opportunistic and pathogenic microrganisms. In this study, firstly, WSSV was isolated from infected shrimp and then multiplied in crayfish. WSSV was purified from the infected crayfish haemolymph by sucrose gradient and confirmed by transmission electron microscopy. In vivo virus titration was performed in shrimp, Penaeus semisulcatus. The LD50 of live virus stock was calculated 10 5.4/mL. Shrimp post-larvae (1-2 g) were treated with gamma-irradiated (different doses) WSSV (100 to 10-4 dilutions) for a period of 10 days. The dose/survival curve for irradiated and un-irradiated WSSV was drawn; the optimum dose range for inactivation of WSSV and unaltered antigenicity was obtained 14-15 kGy. This preliminary information suggests that shrimp appear to benefit from treatment with gammairradiated WSSV especially at 14-15 KGy.

  7. EPR study on non- and gamma-irradiated herbal pills

    Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N. D.

    2011-06-01

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  8. Study of personnel monitoring programs

    Guerra, Aline B.; Lorenzini, Fabiane; Carlos, Janaina; Bernasiuk, Maria E.B.; Rizzatti, Mara R.; Fuentefria, Jose L.B.

    1996-01-01

    Surveillance of several health institutions who use ionizing radiation sources, as well as data from the state of Rio Grande do Sul (Brazil) are studied concerning the use of personnel dosimeters. The results show that several institutions do not provide them and those which provide do not know how to use them

  9. Physicochemical Study of Irradiated polypropylene/Organo :Modified Montmorillonite Composites by Using Electron Beam Irradiation Technique

    Hassan, M.S.

    2008-01-01

    Polypropylene/ Organo modified montmorillonite composites (PP/ OMMT) were prepared by melt blending with a twin screw extruder. The thermal properties by thermo gravimetric analysis (TGA), the dispersion of OMMT of macromolecules by X-ray diffraction (XRD), mechanical properties and the morphology by scanning electron microscopy (SEM) were investigated. The effect of electron beam irradiation on these properties was also studied. The results showed an intercalation between the silicate layers and the PP polymer matrix. The (PP/ OMMT) composites exhibit higher thermal stability and lower mechanical properties than pure polypropylene

  10. Gas bubble network formation in irradiated beryllium pebbles monitored by X-Ray micro-tomography

    Bolier, E; Ferrero, C. [Forschungszentrum Karlsruhe, Zimer 203, Gebaeude 451, Abteilung HVT-TL (Germany); Moslang, A. [Forschungszentrum Karlsruhe GmbH, FZK, Karlsruhe (Germany); Pieritz, R.A. [CNRS, Lab. de Glaciologie et Geophysique de l' Environnement, 38 - Saint Martin d' Heres (France)

    2007-07-01

    Full text of publication follows: The efficient and safe operation of helium cooled ceramic breeder blankets requires among others an efficient tritium release during operation at blanket relevant temperatures. In the past out-of-pile thermal desorption studies on low temperature neutron irradiated beryllium have shown that tritium and helium release peaks occur together. This phenomenon can be interpreted in terms of growth and coalescence of helium bubbles and tritium that either is trapped inside the helium bubbles in form of T{sub 2} molecules or in their strain field. With increasing temperature the bubble density and size at grain interfaces increase together with the probability of interconnected porosities and channel formation to the outer surface, leading to simultaneous helium and tritium release peaks in TDS. For a reliable prediction of gas release up to end-of-life conditions at blanket relevant temperatures, knowledge of the dynamics of bubble growth and coalescence as well as the 3D distribution of bubble network formation is indispensable. Such data could also be used to experimentally validate any future model predictions of tritium and helium release rates. A high resolution computer aided micro-tomography (CMT) setup has been developed at the European Synchrotron Radiation Facility which allowed reconstructing 3-D images of beryllium pebbles without damaging them. By postprocessing the data a 3D rendering of inner surfaces and of interconnected channel networks can be obtained, thus allowing the identification of open porosities in neutron irradiated and tempered beryllium pebbles. In our case Beryllium pebbles of 2 mm diameter had been neutron irradiated in the 'Beryllium' experiment at 770 K with 1.24 x 10{sup 25} nxm{sup -2} resulting in 480 appm He and 12 appm Tritium. After annealing at 1500 K CMT was performed on the pebbles with 4.9 and 1.4 {mu}m voxel resolution, respectively, followed by morphological and topological post

  11. XAFS study on silica glasses irradiated in a nuclear reactor

    Yoshida, Tomoko; Yoshida, Hisao; Hara, Takanobu; Ii, Tatsuya; Okada, Tomohisa; Tanabe, Tetsuo

    2000-01-01

    X-ray absorption technique (XANES and EXAFS) was applied to study the local structures of silica glasses before and after the irradiation in a nuclear reactor. Although our separate photoluminescence (PL) measurements clearly showed the different aspects about oxygen vacancies in these samples, i.e., at least the B 2β type oxygen-deficient center exists as an intrinsic defect in the fused silica glass while another type B 2α center is formed in the synthesized silica glass, such differences did not directly reflect on the X-ray absorption spectra (XANES and EXAFS). However, the curve-fitting analysis of EXAFS showed that the number of oxygen atoms coordinated to Si relatively increased after the irradiation. This result may indicate the occurrence of the structural relaxation in the irradiated samples, that is, a slightly distorted SiO 4 tetrahedra in silica glasses relaxed to the regular SiO 4 tetrahedra due to the break of some connections between SiO 4 units in the silica glasses. Thus, the X-ray absorption technique gave the important information of the in-reactor irradiated silica glasses which complements the results obtained from PL measurements

  12. Biochemical Studies for Producing Biscuits from Irradiated Tomato Processed Wastes

    Al-Kuraieef, A.N.

    2012-01-01

    This study was carried out to produce biscuits as therapeutic diets. Raw materials of tomato processed waste (TPW) were used as a source of some amino acids and elements, (phosphorus, potassium and magnesium), besides amino acids (Phenyl alanine was found to be the first limiting amino acids while lysine was the second limiting one). It was present about 30.66% fiber and 28.1% protein. The total tomato processed wastes remain un-utilized and they not only add to the disposal problem but also aggravate environmental pollution. Tomato processed wastes were irradiated at two doses (1.5 and 2.5 kGy) for preservation. Biscuits were made with supplementation of 5, 10 and 15% (TPW). All samples of biscuits were examined for chemical composition and organoleptic evaluation. Biological assay was carried out on rats fed biscuits containing 15% irradiated and non-irradiated (TPW). The weight gain, serum cholesterol and triglycerides were determined, besides the internal organs. The results obtained showed that 15% (TPW) biscuit had the highest content of lysine, isoleucine and fiber (6.36 and 24.80, respectively) and also scored a good grade. Weight gain, cholesterol and triglycerides were reduced comparable to control and there was significant changes were recorded irradiation treatment on the rats internal organs

  13. Quality assurance and irradiation studies on CMS silicon strip sensors

    Furgeri, Alexander

    The high luminosity at the Large Hadron Collider at the European Particle Physics Laboratory CERN in Geneva causes a harsh radiation environment for the detectors. The most inner layers of the tracker are irradiated to an equivalent fluence of 1.6e14 1MeV-neutrons per cmˆ2. The radiation causes damage in the silicon lattice of the sensors. This increases the leakage current and changes the full depletion voltage. Both of these parameters are after irradiation neither stable with time nor with temperatures above 0oC. This thesis presents the changes of the leakage currents, the full depletion voltages, and all strip parameters of the sensors after proton and neutron irradiation. After irradiation annealing studies have been carried out. All observed effects are used to simulate the evolution of full depletion voltage for different annealing times and annealing temperatures in order to keep the power consumption as low as possible. From the observed radiation damage and annealing effects the sensors of the tra...

  14. Moisture monitoring and control system engineering study

    Carpenter, K.E.; Fadeff, J.G.

    1995-01-01

    During the past 50 years, a wide variety of chemical compounds have been placed in the 149 single-shell tanks (SSTS) on the Hanford Site. A concern relating to chemical stability, chemical control, and safe storage of the waste is the potential for propagating reactions as a result of ferrocyanide-oxidizer and organic-oxidizer concentrations in the SSTS. Propagating reactions in fuel-nitrate mixtures are precluded if the amounts of fuel and moisture present in the waste are within specified limits. Because most credible ignition sources occur near the waste surface, the main emphasis of this study is toward monitoring and controlling moisture in the top 14 cm (5.5 in.) of waste. The purpose of this engineering study is to recommend a moisture monitoring and control system for use in SSTs containing sludge and saltcake. This study includes recommendations for: (1) monitoring and controlling moisture in SSTs; (2) the fundamental design criteria for a moisture monitoring and control system; and (3) criteria for the deployment of a moisture monitoring and control system in hanford Site SSTs. To support system recommendations, technical bases for selecting and using a moisture monitoring and control system are presented. Key functional requirements and a conceptual design are included to enhance system development and establish design criteria

  15. Experimental studies of the reimplantation of irradiated lung in dogs

    Kondo, T; Fujimura, S; Sohara, Y; Kawakami, M; Okaniwa, G [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer

    1978-02-01

    In order to treat the patients with lung cancer who have impaired cardiopulmonary function, a new method is designed, which includes the following steps; 1) pneumonectomy, 2) resection of tumor-bearing lobe, 3) /sup 60/Co irradiation to the remaining lobe, and 4) orthotopic reimplantation of the irradiated lung. The purpose of present study is to clarify the feasibility to use this method clinically. Using adult mongreal dogs, left lung was excised, irradiated and reimplanted. Radiation was carried out from 2,000 rad to 4,000 rad. Viability and function of reimplanted lungs were evaluated by their survival time, serial chest x-ray films, sup(99m)Tc-MAA perfusion scanning, unilateral pulmonary artery occlusion test and histologic examinations. Of 17 animals, 12 survived postoperative period and following results were obtained; 1) no dogs developed pulmonary edema, 2) only one dog was considered to die from acute radiation pneumonitis, 3) serial perfusion scanning showed a gradual decrease in flow distribution to the transplanted lung, 4) the right pulmonary occlusion test done in the dog irradiated with 2,000 rad revealed well reserved pulmonary function 2 months after the operation, and 5) histologically, most irradiated lungs revealed so-called ''late reaction'' of lung fibrosis, but there was the case with nearly normal findings after 6 months from the operation. Although many reports concerning to the radiation pneumonitis are published, there have not been any such reports as the present study. From our experiment, it may be indicated that there is a feasibility to use this new method clinically.

  16. In situ transmission electron microscope studies of ion irradiation-induced and irradiation-enhanced phase changes

    Allen, C.W.

    1992-01-01

    Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing transmission electron microscopes (TEM) have been performed for several decades, involving irradiation-induced and irradiation-enhanced microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact; the development of TEM specimen holder sin which specimen temperature can be controlled in the range 10-2200 K and the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes and presents two case studies involving in situ experiments performed in an HVEM to illustrate the strategies of such an approach of the materials research of irradiation effects

  17. Flux and energy deposition distribution studies inside the irradiation room of the portuguese 60Co irradiation facility

    Portugal, Luis; Oliveira, Carlos

    2008-01-01

    Full text: In December 2003 the irradiator of the Portuguese 60 Co irradiation facility, UTR, was replenished. Eighteen new sources were loaded and the older ones (156) were rearranged. The result was an irradiator with about 10.2 P Bq of total activity. The active area of the irradiator has also increased. Now it uses twenty five of the thirty tubes of the source rack, nine more than in the previous geometry. This facility was designed mainly for sterilisation of medical devices. However it is also used for the irradiation of other products such as cork stoppers, plastics and a limited number of food and feed. The purpose of this work is to perform dosimetric studies inside the irradiation room of a 60 Co irradiation facility, particularly, the flux and energy deposition distributions. The MCNPX code was used for the simulation of the facility. The track average mesh tally capabilities of MCNPX were used to plot the photon flux and energy deposition distributions. This tool provides a fast way for flux and energy deposition mapping. The absorbed dose distribution near the walls of the irradiation room was also calculated. Instead of using meshtallys as before, the average absorbed dose inside boxes lined with the walls was determined and afterwards a plot of its distribution was made. The absorbed dose rates obtained ranged from 5 to 500 Gy.h -1 depending on material being irradiated in process and the location on the wall. These positions can be useful for fixed irradiation purposes. Both dosimetric studies were done considering two different materials being irradiated in the process: cork stoppers and water, materials with quite different densities (0.102 and 1 g.cm-3, respectively). These studies showed some important characteristics of the radiation fields inside the irradiation room, namely its spatial heterogeneity. Tunnelling and shadow effects were enhanced when the product boxes increases its density. Besides a deeper dosimetric understanding of the

  18. Positron lifetime study of electron-irradiated epoxy resins

    Suevegh, K.; Vertes, A.; Wojnarovits, L.; Foeldiak, G.; Liszkai, L.; Kajcsos, Zs.

    1990-01-01

    Two bisphenol-A type epoxy resins were irradiated by electron beam and studied afterwards by positron lifetime spectroscopy. An interesting result is that despite of the considerable amount of free-radicals, no inhibition of positronium formation was observed in the two epoxies. Nevertheless, several serious differences were detected between the studied polymers. The results suggest that the radiation-resistant properties of epoxies depend strongly on the amount of the curing agent. (author) 8 refs.; 2 figs

  19. 1H-MR spectroscopy of the rat hippocampus after whole brain irradiation: an in vivo study

    Ding Weijun; Yang Haihua; Wang Xufeng; Hu Wei; Lei Hao; Li Chunxia; Fang Fang; Fang Zhouxi

    2008-01-01

    Objective: To study the relationships between dynamic changes of the hippocampus metabolites, cognitive impairment and ultrastructural changes of hippocampus in rats during the initial 4 weeks after 6 MV X-ray whole-brain irradiation. Methods: 65 rats were randomly divided into foul groups as sham control (n=5), 10 Gy, 20 Gy and 30 Gy groups (n=20). The learning and memory ability was measured with the Y maze test 4, 8 weeks, 2, 6 months after irradiation. 1 H-MRS was performed after 2 or 4 weeks' brain irradiation. The ultrastructural changes of the hippocampus were observed by electronic microscope. Results: The learning and memorizing ability of irradiation groups was significantly different from that of control group. Compared with control group, the NAA/Ct and Cho/Cr ratio in the left hippocampus in 10 Gy, 20 Gy and 30 Gy groups at 2 weeks and 4 weeks decreased significantly. Neuronal mitochondria edema, endothelial cells swelling and lamina dissociation in myelin sheath were demonstrated in various degrees by electromicroscope at 4 weeks following whole brain irradiation. Conclusions: 1 H-MRS can be used to non-invasively monitor the metabolic changes, both quantitatively and dynamically, of the irradiated rat brain, 1 H-MRS is superior to MRI in detecting early abnormality of the brain. The NAA/Cr and Cho/Cr ratio in irradiated hippocampus could reflect the severity of the brain injury to some extent. (authors)

  20. Toxicological studies on irradiated food and food constituents

    Schubert, J.

    1978-01-01

    Selected aspects of the genotoxicology and chemistry of irradiated foods and food components are critically examined and compared with other food processing operations such as cooking, and intentional use of food additives. For example, it is estimated that if 10% of an average daily diet contained irradiated (<1.0Mrad) foods, the daily consumption of radiolytic products would be 2-20mg/d compared with a total of approximately 4000mg/d of intentional food additives and approximately 80mg/d of toxic inorganic and organic environmentally derived contaminants. Several recommendations for the genotoxicological testing of irradiated foods are given, including: (1) that feeding tests include a control diet consisting of food processed by one of the standard methods such as thermalization; (2) that more use be made of positive controls so as to have a 'built-in' measure of sensitivity and responsiveness; (3) that a battery of in vitro and in vivo short-term mutagenicity tests be performed prior to the carrying out of the long-term feeding tests; and (4) that an irradiated food be tested after it is cooked in the manner normally consumed, which may, of course, include the raw or uncooked state as well. An outline of current genetic-toxicological testing schemes is provided and examined. Emphasis is given to a modification in the protocols for the Ames mutagenicity tests leading to a reduction in the evidence of false positives and false negatives. Also described is a procedure for systematically studying combined or interactive effects, acute or chronic, which requires no more effort than that needed for testing a single agent and which yields complete dose-response curves. It is concluded that food irradiation, as a physical process, appears more advantageous from the genotoxicological, chemical, and pollution aspects than well-accepted, but actually rarely tested, physical processes such as canning. (author)

  1. An experimental studies of skin autograft in irradiated bed

    Ueda, Minoru

    1981-01-01

    Effects of irradiation to revascularization and skin grafting were studied. Wistar rats were irradiated with 1000, 2000, and 3000 rad of x-ray. One 2, 4, 6, 8, 12, and 24 weeks after irradiation each group, consisted of 10 rats, was compared with that of 34 untreated rats. A new score system of skin reaction was proposed. The highest moist skin reaction was observed after 2 weeks in 3 irradiated groups. In the 2000 and 3000 rad groups, the acute reaction appeared with 1 week latent period and recovered in 8 weeks followed by marked skin atrophy and epilation, while in the 1000 rad group complete recovery was observed in 3 weeks without late squlae. In order to carry out microangiography, a new device to inject the contrast medium at constant temperature and pressure was used. Marked inflammation was observed in 4 weeks, began to recover in 4 weeks, and hypovascular area appeared in 8 weeks. As for the blood area density, no variation was found for the 1000 rad group. However, in the 2000 and 3000 rad groups, the highest density was observed in 2 weeks and decreased after 8 weeks to that lower than the control. Revascularization after the skin grafting was followed by microangiography. In the control group, primary and secondary revascularization was observed one and 3 days after transplantation. As for the 3000 rad groups both revascularizations were hardly recognized when transplanted 8 weeks after irradiation. The optimum time for skin grafting was found to be acute or subacute period of the vascular damage. (Nakanishi, T.)

  2. Comparative study of thermoluminescence detection methods for irradiated spices

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

    1995-01-01

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

  3. Quality assurance of the UV irradiances of the UV-B Monitoring and Research Program: the Mauna Loa test case

    Zempila, Melina Maria; Davis, John; Janson, George; Olson, Becky; Chen, Maosi; Durham, Bill; Simpson, Scott; Straube, Jonathan; Sun, Zhibin; Gao, Wei

    2017-09-01

    The USDA UV-B Monitoring and Research Program (UVMRP) is an ongoing effort aiming to establish a valuable, longstanding database of ground-based ultraviolet (UV) solar radiation measurements over the US. Furthermore, the program aims to achieve a better understanding of UV variations through time, and develop a UV climatology for the Northern American section. By providing high quality radiometric measurements of UV solar radiation, UVMRP is also focusing on advancing science for agricultural, forest, and range systems in order to mitigate climate impacts. Within these foci, the goal of the present study is to investigate, analyze, and validate the accuracy of the measurements of the UV multi-filter rotating shadowband radiometer (UV-MFRSR) and Yankee (YES) UVB-1 sensor at the high altitude, pristine site at Mauna Loa, Hawaii. The response-weighted irradiances at 7 UV channels of the UV-MFRSR along with the erythemal dose rates from the UVB-1 radiometer are discussed, and evaluated for the period 2006-2015. Uncertainties during the calibration procedures are also analyzed, while collocated groundbased measurements from a Brewer spectrophotometer along with model simulations are used as a baseline for the validation of the data. Besides this quantitative research, the limitations and merits of the existing UVMRP methods are considered and further improvements are introduced.

  4. Electron spin resonance intercomparison studies on irradiated foodstuffs

    Raffi, J.

    1992-01-01

    The results of intercomparison studies organized by the Community Bureau of Reference on the use of electron spin resonance spectroscopy for the identification of irradiated food are presented. A qualitative intercomparison was carried out using beef and trout bones, sardine scales, pistachio nut shells, dried grapes and papaya. A quantitative intercomparison involving the use of poultry bones was also organized. There was no difficulty in identifying meat bones, dried grapes and papaya. In the case of fish bones there is a need for further kinetic studies using different fish species. The identification of pistachio nut shells is more complicated and further research is needed prior to the organization of a further intercomparison. Laboratories were able to distinguish between chicken bones irradiated in the range 1 to 3 KGy or 7 to 10 KGy although there was a partial overlap between the results from different laboratories

  5. Electron spin resonance intercomparison studies on irradiated foodstuffs

    Raffi, J [CEA Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (FR)

    1992-07-01

    The results of intercomparison studies organized by the Community Bureau of Reference on the use of electron spin resonance spectroscopy for the identification of irradiated food are presented. A qualitative intercomparison was carried out using beef and trout bones, sardine scales, pistachio nut shells, dried grapes and papaya. A quantitative intercomparison involving the use of poultry bones was also organized. There was no difficulty in identifying meat bones, dried grapes and papaya. In the case of fish bones there is a need for further kinetic studies using different fish species. The identification of pistachio nut shells is more complicated and further research is needed prior to the organization of a further intercomparison. Laboratories were able to distinguish between chicken bones irradiated in the range 1 to 3 KGy or 7 to 10 KGy although there was a partial overlap between the results from different laboratories.

  6. Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

    Jaiswal, Manoj Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India)

    2013-11-01

    Thin films of tin(IV) oxide (SnO{sub 2}) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au{sup 8+} using 1 pnA current at normal incidence with ion fluences varying from 1 × 10{sup 11} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2}. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV–Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm{sup −1} in FTIR spectrum confirmed the O–Sn–O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO{sub 2} were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

  7. Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

    Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

    2013-11-01

    Thin films of tin(IV) oxide (SnO2) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au8+ using 1 pnA current at normal incidence with ion fluences varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV-Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm-1 in FTIR spectrum confirmed the O-Sn-O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO2 were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

  8. Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

    Shinozaki, Yoshiharu; Hogetsu, Daisuke; Okuyama, Norio; Manabe, Takashi; Sasagawa, Tatsuru.

    1981-01-01

    The preparation of alcohol extracts from gamma-irradiated potatoes of the ''Danshaku'' variety and their chemical aspects were studied. The final concentrate of alcohol extracts from potatoes showed pH values of 3 -- 4. The o-quinones or ''radiotoxins'' reported by Kuzin, et al. were not detected in the alcohol extracts from potatoes of this variety by high performance liquid chromatography (HPLC) analysis, paper chromatography and the model enzymatic experiment. (author)

  9. Structural changes in irradiated steels. An example of industrial studies

    May, R [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Miloudi, S [Electricite de France (France)

    1997-04-01

    The security of nuclear reactors depends on knowledge about the degradation of some of their components by neutron irradiation. It is anticipated in the design of power reactors so as to ensure their safe operation. The long-time behaviour of reactor components is investigated. These studies serve to verify that the predictions concerning mechanical properties of reactors hold, but also to better understand the processes leading to degradation in order to find means for safely increasing the lifetimes of power plants. (author).

  10. Studies of neutron irradiation effects at IPNS-REF

    Kirk, M.A.

    1983-09-01

    Neutron irradiation effects studies at the Radiation Effects Facility (REF) at the Intense Pulsed Neutron Source (IPNS) located at Argonne National Laboratory (ANL) are reviewed. A brief history of the development of this user facility is followed by an overview of the scientific program. Experiments unique to a spallation neutron source are covered in more detail. Future direction of research at this facility is suggested

  11. Growth studies on Lens culinaris after gamma irradiation

    Ahmad, S.; Bokhari, F.S.; Shahnaz, F.

    1996-01-01

    A study on growth parameters was carried out on two varieties of Lens culinaris after gamma irradiation. Experiment was conducted at Botanical Garden, Bahauddin Zakariya University, Multan in 1993. The germination percentage, survival percentage, height, branch number, pods per plant and 100-seed weight decreased with the increasing dose of radiation. Comparing the two varieties, variety-86642 appeared more sensitive to radiation than variety-87528

  12. New temperature monitoring devices for high-temperature irradiation experiments in the high flux reactor Petten

    Laurie, M.; Futterer, M. A.; Lapetite, J. M. [European Commission Joint Research Centre, Institute for Energy, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Fourrez, S. [THERMOCOAX SAS, BP 26, Planquivon, 61438 Flers Cedex (France); Morice, R. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris (France)

    2009-07-01

    Within the European High Temperature Reactor Technology Network (HTR-TN) and related projects a number of HTR fuel irradiations are planned in the High Flux Reactor Petten (HFR), The Netherlands, with the objective to explore the potential of recently produced fuel for even higher temperature and burn-up. Irradiating fuel under defined conditions to extremely high burn-ups will provide a better understanding of fission product release and failure mechanisms if particle failure occurs. After an overview of the irradiation rigs used in the HFR, this paper sums up data collected from previous irradiation tests in terms of thermocouple data. Some research and development work for further improvement of thermocouples and other on-line instrumentation will be outlined. (authors)

  13. Synthetic study of reactor irradiation for medical use

    An, Shigehiro; Furuhashi, Akira; Kanda, Keiji; Sumita, Kenji; Kakihana, Hidetake.

    1978-01-01

    This report is described on the results of the study on the reactor irradiation for medical use shared by the Nuclear Engineering Research Laboratory, Faculty of Engineering, University of Tokyo, and other seventeen facilities. Boron neutron-capturing therapy developed in Japan is extremely significant treating method for tumors by destroying tumor cells of encephaloma, etc. selectively. This is the synthetic study for promoting the above therapeutic method. Two existing reactors were reconstructed into the thermal neutron reactors for boron neutron-capturing therapy. The various preparatory and physical researches were made with the reconstruction, and the therapy was tried on eleven cases. Further experiments were made on the following points: (1) To promote treatment on encephaloma by boron neutron-capturing therapy. (2) To develop its application to malignant tumors other than encephaloma. (3) Animal irradiation experiments. (4) The basic experiments on the cellular level. (5) The study of remote controlled anesthesia. (6) To control irradiated dose. (7) To improve boron compounds. (8) To condense radioisotopes. (Kobatake, H.)

  14. Forecasting of the lethality in cases of nonuniform accidental irradiation (experimental studies at external gamma irradiation of rats)

    Ingilizova, K.

    1983-01-01

    A model is suggested that enables the prediction of death probability for the body (L) within the whole lethality dose range (DL 0 -DL 100 ), on the basis of predetermined physical characteristics: in cases of uneven external wholebody irradiation. Some biological effects of 4 variants of uneven irradiation have been studied, i.e. ventro-dorsal (V-D), dorso-ventral (D-V), cranio-caudal (Cr-Ca) and caudo-cranial (Ca-Cr). The following basic conclusions have been drawn: 1. The study of the biological effects of uneven irradiation, when estimated by the lethality factor, points out the lower efficiency of the former, if compared to even irradiation. 2. The even irradiation lethality in the conducted experiments, according to the ALE data and the postradiation mortality dynamics, is determined basically by the damage of the bloodforming tissue and the animals die of bone marrow syndrome. 3. The uneven irradiation, estimated by the total weight factor, is of lower efficiency than the even one. 4. The radiation-induced hypoplasia of the studied organs is exponential in character. 5. An original model for predicting radiation mortality in cases of uneven irradiation has been constructed. The model gives the possibility of relating the alterations in the index of biological efficiency reduction to the wholebody irradiation factor, as well as to the two systems with highest radiosensitivity: red bone marrow and the small intestine. The model helps determining the numerical value of death probability, depending on the average body irradiation doses and the integral unevenness factors for RBM. (author)

  15. Comparison of neutron and gamma irradiation effects on KU1 fused silica monitored by electron paramagnetic resonance

    Bravo, D. [Department Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain)], E-mail: david.bravo@uam.es; Lagomacini, J.C. [Department Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Leon, M.; Martin, P. [Materiales para Fusion, CIEMAT, Avda. Complutense 22, E-28040 Madrid (Spain); Martin, A. [Department Fisica e Instalaciones, ETS Arquitectura UPM, E-28040 Madrid (Spain); Lopez, F.J. [Department Fisica de Materiales, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Ibarra, A. [Materiales para Fusion, CIEMAT, Avda. Complutense 22, E-28040 Madrid (Spain)

    2009-06-15

    Electron paramagnetic resonance (EPR) studies have been carried out on KU1 fused silica irradiated with neutrons at fluences 10{sup 21} and 10{sup 22} n/m{sup 2}, and gamma-ray doses up to 12 MGy. The effects of post-irradiation thermal annealing treatments, up to 850 deg. C, have also been investigated. Paramagnetic oxygen-related defects (POR and NBOHC) and E'-type defects have been identified and their concentration has been measured as a function of neutron fluence, gamma dose and post-irradiation annealing temperature. It is found that neutrons at the highest fluence generate a much higher concentration of defects (mainly E' and POR, both at concentrations about 5 x 10{sup 18} spins/cm{sup 3}) than gamma irradiations at the highest dose (mainly E' at a concentration about 4 x 10{sup 17} spins/cm{sup 3}). Moreover, for gamma-irradiated samples a lower treatment temperature (about 400 deg. C) is required to annihilate most of the observed defects than for neutron-irradiated ones (about 600 deg. C)

  16. Theoretical Study of Irradiation Effects in Close Binaries

    Srinivasa Rao, M.

    2009-06-01

    Full Text Available The effect of irradiation is studied in a close binary systemassuming that the secondary component is a point source, moving in a circularorbit. The irradiation effects are calculatedon the atmosphere of the primary component in a 3-dimensional Cartesiancoordinate geometry. In treating the reflection effect theoretically, the totalradiation $(S_mathrm{T}$ is obtained as the sum of the radiation of 1 the effect ofirradiation on the primary component which is calculated by using onedimensional rod model $(S_mathrm{r}$ and 2 the self radiation of the primarycomponent which is calculated by using the solution of radiative transferequation in spherical symmetry $(S_mathrm{s}$. The radiation field is estimated alongthe line of sight of the observer at infinity. It is shown how the radiationfield changes depending on the position of the secondary component.

  17. Study of 316 stainless steel swelling due to neutron irradiation

    Furutani, Gen; Konishi, Takao

    2000-01-01

    Large stresses will be generated in the austenitic stainless steel core internals of pressurized water reactors (PWRs) if excessive swelling occurs after long periods of operation. As a result, deformation or stress corrosion cracking (SCC) could occur in the core internals. However, data on the swelling of irradiated austenitic stainless steel in actual PWRs is limited. In this study, mechanical tests, measurement of produced helium amount and analysis using transmission electron microscopes were carried out on a cold-worked (CW) 316 stainless steel flux thimble tube irradiated up to approximately 35 dpa in a Japanese PWR. The swelling was evaluated to be approximately 0.02%. This level of swelling was much lower than the swelling of the more than several percent that has been observed in fast breeder reactors. (author)

  18. Study of irradiation effects in non-metallic conductors

    Atobe, Kozo; Fukuoka, Noboru; Honda, Makoto; Kondo, Tadashi; Morishima, Kouichi; Okada, Moritami; Nakagawa, Masuo

    1998-01-01

    The production of point defects induced by reactor and the thermal behavior of defects in sintered AlN and c-BN have been investigated using the optical absorption and electron spin resonance (ESR) methods. The absorption band at 370 nm (AlN) and the structureless absorption over the visible region are observed. These specimens also show ESR signals with g-value 2.007 (AlN), 2.006 (BN), which are probably caused by N vacancies with a trapped electron. In addition to these experiments, the difference of the photoluminescence(PL) lines on neutron irradiated CZ-Si and FZ-Si has been also studied. The models of the defect associated with neutron irradiation are discussed. (author)

  19. Monte Carlo studies of the Portuguese gamma irradiation facility. The irradiator geometry and its influence on process parameters

    Oliveira, C.; Ferreira, L.; Salgado, J.

    2001-01-01

    The paper describes a Monte Carlo study of dose distributions, minimum dose and uniformity ratio for the Portuguese Gamma Irradiation Facility. These process parameters are calculated using the MCNP code for several irradiator geometries. The comparison of the simulated results with the experimental results carried out using Amber Perspex dosimeters in a routine process of the gamma facility for a given material composition and density reveals good agreement. The results already obtained allow to conclude that the dose uniformity is not very sensitive to the irradiator geometry for density value ρ = 0.1 and for a dynamic process. (orig.)

  20. Experimental study of swelling of irradiated solid methane during annealing

    Shabalin, E.; Fedorov, A.; Kulagin, E.; Kulikov, S.; Melikhov, V.; Shabalin, D.

    2008-01-01

    Solid methane, notwithstanding its poor radiation properties, is still widely in use at pulsed neutron sources. One of the specific problems is radiolytic hydrogen gas pressure on the walls of a methane chamber during annealing of methane. Results of experimental study of this phenomenon under fast neutron irradiation with the help of a specially made low temperature irradiation rig at the IBR-2 pulsed reactor are presented. Peak pressure on the wall of the experimental capsule during heating of a sample irradiated at 23-35 K appeared to have a maximum of 27 bar at the absorbed dose 20 MGy, and then falls down with higher doses. Pressure always reached its peak value within the temperature range 72-79 K. Generally, three phases of methane swelling during heating can be distinguished, each characterized by proper rate and intensity. Results of this study were accounted for in design of the solid methane moderator of the second target station of the ISIS facility (England)

  1. Value of subtyping in studies of irradiation and human leukaemia

    Darby, S C

    1985-01-01

    The two largest studies of the effects of irradiation on humans in postnatal life are described. These are 1) the Ankylosing Spondylitis Study(ASS) carried out on patients given X-ray therapy as treatment for spondylitis in the UK and 2) the Life Span Study(LSS) carried out on the survivors of the atomic bombings of Hiroshima and Nagasaki. From these studies, a limited degree of subtyping of leukemias is indicated. Chronic lymphatic leukemia is much less readily induced by radiation than the other major subtypes. The inducibility of acute myeloid leukemia increases with age at exposure.

  2. Study of acute ecotoxicity of Resveratrol in Daphnia similis irradiated and non-irradiated

    Ormenio, Matheus B.; Mazieiro, Joana S.; Rogero, Sizue O.; Rogero, José R. Rogero

    2017-01-01

    Resveratrol is synthesized by a wide variety of plants in response to ultraviolet (UV) radiation or action of certain pathogens. It is a compound with ability to protect cells from free radicals, responsible for the natural process of cellular aging. It is known that resveratrol has a radiomodifying effect, in addition to the antioxidant potential, anti-inflammatory, against cardiovascular diseases. The increasing use of resveratrol as a function of biological activities has led to concern about toxicity. In the ecotoxicological area, acute ecotoxicity tests are performed on aquatic organisms that lethal effects of certain substances and / or environmental samples. These tests are important in providing critical information for the development and adoption of criteria for improvement environmental quality. In these tests Cladoceras are widely used as test organisms due to their extreme susceptibility to toxicants in the environment and because they are easy to handle in the laboratory. In this study, it was used Daphnia similis to verify the toxic effect of resveratrol on this non-irradiated organism and irradiated with gamma radiation. First, toxicity studies of resveratrol and gamma Daphnia similis, where the lethal dose (LD50) of the 585.43 Gy radiation was determined and the EC50 concentration of resveratrol that causes immobility in 50% of the organisms in the assay, of 6.08 μM. Based on these data, the study will be continued to assess the toxic effect of radiation on organisms that have been exposed prior to resveratrol, i.e, to verify the radiomodifying effect of resveratrol

  3. Economic Feasibility Study for Using Irradiation Technology in Preservation of Animalism Foods

    El Gameel, E.A.

    2011-01-01

    The present study discus the economic feasibility for the preservation animalism foods by using irradiation technology. This study has included the technical data, regression foretelling for the throughput, determination of irradiators types and radiation sources activity. This study comprises the financial analysis for the establishment animalism foods irradiation facilities (types: tote box, pallet conveyor) and the national return

  4. Study on the Long Term Effects of Radiation on Irradiated Manawthukha Rice Grain (Mahsuri-M)

    Aye Aye Mar; Aye Aye Mon; Hnin Hnin Than; Ba Han; Tin Tin; Myint U

    2008-03-01

    Radioactivity monitoring of first and second generations Manawthukha paddy grain before cultivations were carried out. It was found out that there were no induced activity. Therefore it can be concluded that similarly it will be the same for third generation rice. The second generation rice was obtained from cultivation and harvesting of first generation [(i) non-irradiated (control), (ii) gamma-irradiated, (iii) neutron-one hour irradiated, (iv) neutron one-day irradiated rice]. Agronomical characteristics of three different types of generation of rice were studied. Morphological characteristics studies such as plant height, leaf width and panicle length,there was no large variation between three generations of rice. Phenotypes were found to be stable. Yield improvement was calculated. Nutritional values of rice generation were studied. They were (i) element analysis by different methods (NAA, EDXRF and AAS), vitamin determination and protein percent determination. There was no distinctive difference between first, second and third generation rice. In element analysis, eleven elements such as Mg, Mn, Na, K, Cl, Al, Ca, Fe, Zn, P and Cu were observed by NAA, AAS and EDXRF methods. Vitamin content (B1, B2) and protein content were also studied. Determination of amylose content, gel consistency and gelatinization temperature were involved in grain quality study. There was no large variation in three generations. Surface texture of first, second and third generation Manawthukha rice were studied by Scanning Electron Microscope (SEM). It was observed that the change of texture from generation to generation tend to become more distinctive in third generation.

  5. Radiological assessments, environmental monitoring, and study design

    Hansen, W.R.; Elle, D.R.

    1980-01-01

    Studies of the behavior of transuranic elements in the environment form the basic data for applied programs in radiological assessment, environmental monitoring, derivation of radiation-protection standards, and environmental impact statements. This chapter introduces some of the major information requirements of these applications of transuranic research data. Characteristics of the source terms from nuclear activities usually are needed for an analysis of environmental pathways or deployment of monitoring systems. Major inhalation and ingestion pathways are considered in assessments of hazards from transuranics and are discussed from the viewpoint of research needed

  6. Pilotscale studies of dried fish irradiation. Part of a coordinated programme in Asian Regional Cooperative Project on Food Irradiation

    Maha, M.

    1983-03-01

    Pilot scale experiments on irradiation of semi-dried mackerel with regard to shelf-life extension, packaging, transportation and cost-analysis were carried out. The results showed that dipping mackerel in saturated brine for 5 hours and then soaking it in 2% potassium sorbate before sun-drying to approximately 40% moisture content produced a good quality product. Sorbate treatment was effective in controlling mould growth while irradiation with 2 kGy was effective in reducing the bacterial load. Carton boxes were found most suitable as packaging material for irradiated dried fish from the point of view of strength, convenience for irradiation and better dose uniformity ratio than polypropylene bags which have ununiform configuration. Irradiation with doses up to 10 kGy has no significant effect on physical properties of the packaging materials tested. Carton boxes of 20 kg capacity provided with strapping bands are durable for land or sea transportation of dried fish. A radiation dose of 0.5 kGy was sufficient to control insect damage and reduce mould growth on dried fish. Irradiated dried fish can be marketed for 3-4 months at ambient conditions in Jakarta. Small scale consumer studies of irradiated samples using employees of the institute showed no negative reactions. Using the small pilot irradiator at CAIR and assuming 1 kGy minimum dose for dried fish, the total cost of irradiation and packaging was estimated to be approximately 10 U.S. cents/kg of fish, which is about 2-3% of the cost of the product

  7. The Experimental Study Of Effects Of Irradiation On Osseointegration

    Park, Kwan Soo; Lee, Sang Rae; Hwang, Eui Hwan [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    1999-02-15

    The purpose of this study was to investigate the effects of the Co-60 gamma irradiation on the osseointegration. 2.0 mm titanium alloy screw implants were placed in the tibial metaphysics of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15 Gy from 6{sup 0C}o teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non-irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20 mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy.The obtained results were as follows; 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.

  8. Microbiological and physico-chemical studies on irradiated dewatered sludge

    Hilmy, N.; Suwirma, S.; Harsoyo; Suhadi, F.

    1987-01-01

    Microbiological and physico-chemical studies on irradiated dewatered sludge. Microbiological and physico-chemical dewatered have been carried out and non-irradiated dewatered sludge of Jakarta city, collected during the rainy and dry season. Total bacterial counts of non-irradiated dewatered sludge with water content of around 20%, were found to be about 7x10 8 per g during the rainy season and 7x10 6 up to 1.3x10 8 per g during the dry season, while coliform fecal Streptococcus and Pseudomonas were found to be 1.6x10 4 to 1.0x10 7 , 3x10 5 , and 5x10 3 per g, respectively. No Salmonella, Shigella and Vibrio were detected in all of the samples observed. About 10% of the total number of coliforms were found to be Escherichia coli. A dose of 6 kGy could eliminate the coliform, E. Coli, fecal Streptococcus and Pseudomonas from all of the dewatered sludge observed. The nutrient value of the sludge was sufficient, i.e. total nitrogen content ranged between 1 and 4,42%, phosphorus between 1.55 and 2.36%, and potassium between 0,1 and 0,2% of dry matter. Heavy metal contents were found a little bit high to be applied as animal feed, but it is still acceptable for soil conditioner. Combining 3 months storage at ambient environment and irradiation dose of 2.5 kGy were found to work synergistically to eliminate coliforms and E. Coli from sludge. (author). 8 figs, 17 refs

  9. Study by internal friction of curing low temperature irradiation defects in graphite

    Rouby, Dominique.

    1974-01-01

    Micromechanical properties and anelastic effects of neutrons irradiated graphites at 300 and 77 0 K are investigated by internal friction analysis and elasticity modulus variations. Defects created by irradiation are studied and evolution versus dose and annealing is followed [fr

  10. Monitoring for fuel sheath defects in three shipments of irradiated CANDU nuclear fuel

    Johnson, H.M.

    1978-01-01

    Analyses of radioactive gases within the Pegase shipping flask were performed at the outset and at the completion of three shipments of irradiated nuclear fuel from the Douglas Point Generating Station to Whiteshell Nuclear Research Establishment. No increases in the concentration of active gases, volatiles or particulates were observed. The activity of the WR-1 bay water rose only marginally due to the storage of the fuel. Other tests indicated that minimal surface contamination was present. These data established that defects in fuel element sheaths did not arise during the transport or the handling of this irradiated fuel. The observation has significance for the prospect of irradiated nuclear fuel transfer and handling in preparation for storage or disposal. (author)

  11. Characterization and performances of a monitoring ionization chamber dedicated to IBA-universal irradiation head for Pencil Beam Scanning

    Courtois, C. [LPC (IN2P3-ENSICAEN-UNICAEN), 6 Boulevard Maréchal Juin, 14050 Caen (France); Boissonnat, G., E-mail: boissonnat@lpccaen.in2p3.fr [LPC (IN2P3-ENSICAEN-UNICAEN), 6 Boulevard Maréchal Juin, 14050 Caen (France); Brusasco, C. [IBA, 3 Chemin du Cyclotron, 31348 Louvain-la-Neuve (Belgium); Colin, J.; Cussol, D.; Fontbonne, J.M. [LPC (IN2P3-ENSICAEN-UNICAEN), 6 Boulevard Maréchal Juin, 14050 Caen (France); Marchand, B.; Mertens, T.; Neuter, S. de [IBA, 3 Chemin du Cyclotron, 31348 Louvain-la-Neuve (Belgium); Peronnel, J. [LPC (IN2P3-ENSICAEN-UNICAEN), 6 Boulevard Maréchal Juin, 14050 Caen (France)

    2014-02-01

    Every radiotherapy center has to be equipped with real-time beam monitoring devices. In 2008, we developed an ionization chamber in collaboration with the IBA (Ion Beam Applications) company. This monitoring device called IC2/3 was developed to be used in IBA universal irradiation head for Pencil Beam Scanning (PBS). Here we present the characterization of the IC2/3 monitor in the energy and flux ranges used in protontherapy. The equipment has been tested with an IBA cyclotron able to deliver proton beams from 70 to 230 MeV. This beam monitoring device has been validated and is now installed at the Westdeutsches Protonentherapiezentrum Essen protontherapy center (WPE, Germany). The results obtained in both terms of spatial resolution and dose measurements are at least equal to the initial specifications needed for PBS purposes. The detector measures the dose with a relative uncertainty lower than 1% in the range from 0.5 Gy/min to 8 Gy/min while the spatial resolution is better than 250μm. The technology has been patented and five IC2/3 chambers were delivered to IBA. Nowadays, IBA produces the IC2/3 beam monitoring device as a part of its Proteus 235 product.

  12. Monitoring of the morphologic reconstruction of deposited ablation products in laser irradiation of silicon

    Vlasova M.

    2008-01-01

    Full Text Available Using electron microscopy, atomic force microscopy, X-ray microanalysis, and IR spectroscopy, it was established that, in the regime of continuous laser irradiation of silicon at P = 170 W in different gaseous atmospheres with an oxygen impurity, SiOx composite films with a complex morphology form. The main components of ablation products are clusters that form during flight of ablation products and as a result of separation of SiOx-clusters from the zone of the irradiation channel. The roughness and density of the films depend on the heating temperature of the target surface and the type of deposited clusters.

  13. Determination of cross sections of nuclear reactions to use Al as monitoring foil in heavy ion irradiation with 20Ne projectile

    Chowdhury, D.P.; Datta, J.; Guin, R.; Verma, R.

    2009-01-01

    The beam current is generally accurately measured using monitoring foils during the irradiation of thick samples by high energy ion beams. The cross sections of many nuclear reactions induced by light particles are available in literature for use as monitoring foil. However, such cross sections of heavy ion induced reactions are not reported much for their use in applied works. We have determined cross sections of two nuclear reactions, 27 Al ( 20 Ne,2p2n) 43 Sc and 27 Al ( 20 Ne, 2pn) 44m Sc, to use Al as monitoring foil for the irradiation with 20 Ne heavy ion beam. (author)

  14. Studies of beam position monitor stability

    Tenenbaum, P.

    1998-05-01

    The authors present the result s from two studies of the time stability between the mechanical center of a beam position monitor and its electrical/electronic center. In the first study, a group of 93 BPM processors was calibrated via Test Pulse Generator once per hour in order to measure the contribution of the readout electronics to offset drifts. In the second study, a triplet of stripline BPMs in the Final Focus Test Beam, separated only by drift spaces, was read out every 6 minutes during 1 week of beam operation. In both cases offset stability was observed to be on the order of microns over time spans ranging from hours to days, although during the beam study much worse performance was also observed. Implications for the beam position monitor system of future linear collider systems are discussed

  15. Monitoring external irradiation FI4P CT96 0049 final project overview

    Wahl, W.; Wielunski, M.; Andrasi, A.; Palfalvi, J.; Schmitzer, C.; Stadtmann, H.

    1999-08-01

    This project is devoted to the innovative development of more sensitive and more specific methods for the monitoring of external radiation, as described in the 4th framework programme Nuclear Fission Safety executive work program item D.2.5. The general topic ('Evaluation of Radiation Risk') defines the area of radiation protection where this research effort is located. Hence, the rational behind such a project is the extension of knowledge about the risk of human exposure by improving the detection methodology. This may be achieved by enhancing the sensitivity of the detection element, by exploiting more detailed information on the type and energy of radiation, and by in depth understanding of the photon and neutron interaction in order to aid the interpretation of acquired data. The radiation may be characterised per se, i.e. free in air, however, more relevant for practical purposes are the interaction processes with matter. Since this interaction of radiation with neighbouring bodies - or the material composition of the measuring element itself - must not be neglected, the involvement of phantoms both in the modelling process and the experimental verification was proposed. The overall objective of this project, therefore, is the modelling and the development of an innovative semiconductor sensor and suitable phantoms for the application in mixed photon and neutron fields. The chosen approach relies heavily on numerical modelling and experimental verification of the detector design, taking into account the back-scatter effects represented by the specific phantoms involved. Based on commercially available silicon pin diodes, new detectors are being develooped, simulated and experimentallly verified as a joint effort amongst the project partners. The partnership constellation consists of two poject partners and a Hungarian subcontractor fully integrated in the line of work. Neuron modelling: For neutron detection the converter of radiator technology was adopted

  16. Study on the storage properties of irradiated ginger

    Wang Shoujing; Yu Zihou; Sun Shouyi; Zou Jiwan; Zhang Qizhi; Sun Hongchun; Lv Tiexin; Liu Xiaoyong

    2004-01-01

    The γ-ray irradiation could cause the loss of Vc during the early stage of storage, however, after 150 days' storage there were no significant differences of Vc content between irradiated and non-irradiated samples. The content of reduced sugar was increased by irradiation especially with 150 and 250 Gy. When ginger were irradiated with 250 Gy and stored at room temperature for 120 days, the content of Met and Arg decreased obviously, but the contents of other 16 amino acids were not affected. The respiration rate of irradiated ginger reached its peak at 7-9 days of storage, and from then it kept lower level for the rest storage time. The electrolyte permeability increased slightly after γ-irradiation. Irradiation with 80-400 Gy had no effects on lipid isoenzyme zymogram

  17. Monitoring and Microbiological Characteristics of Physico-chemical Dates of Canned Juice by Gamma Irradiation

    Arfa, Darine

    2008-01-01

    During this work, we are interested to the survey of the effect of gamma irradiation on the conservation of the juices of the dates. The results gotten of the microbiological and physico-chemical analysis done on the four samples, show the efficiency of the method for the conservation of the juices of the dates. (Author)

  18. Antibodies to UV irradiated DNA: the monitoring of DNA damage by ELISA and indirect immunofluorescence

    Wani, A A; Gibson-D' Ambrosio, R E; D' Ambrosio, S M [Ohio State Univ., Columbus (USA). Dept. of Radiology

    1984-10-01

    The enzyme-linked immunosorbant assay (ELISA) was modified to (1) characterize antibodies raised in rabbits against UV-irradiated single-stranded DNA (UVssDNA) complexed with methylated BSA and (2) directly detect pyrimidine dimers in irradiated DNA. The antisera specifically bound to UVssDNA, UVpoly(dT) and to a limited extent to UVdsDNA and UVpoly(dC). Fifty per cent of the maximum antibody binding was observed at a 1-5000 dilution against UVssDNA. Binding to ssDNA and poly(dT) was observed only at much higher concentrations of antibody, whereas no binding to double stranded DNA (dsDNA) was observed. The extent of binding of the antibody was dependent on the UV dose to DNA and the concentration of antigen immobilized on the plate. The ability of various irradiated molecules, DNA, homopolymers and linkers to act as inhibitors of antibody binding establishes that the antigenic determinants are mainly thymine homodimers with lower affinity for cytosine dimers. Potential usefulness of the antibodies to directly quantitate pyrimidine dimers in cells exposed to UV radiation was determined by indirect immunofluorescence. Flow cytometric analysis of immunostained human lymphocytes irradiated with 254 nm radiation indicated that greater than 50% of the population had significantly higher fluorescent intensity than unirradiated cells.

  19. Application of the in-beam PET therapy monitoring on precision irradiations with helium ions

    Fiedler, F.

    2008-01-01

    The main goal of the present dissertation was to extend the in-beam PET method to new ion types. It was shown that the in-beam PET method can also be applied for 3 He irradiations. For this experiments on a 3 He beam were performed. The activity yield is at equal applied dose about three times larger than at 12 C irradiations. The reachable range resolution is smaller than 1 mm. At the irradiation of an inhomogeneous phantom it was shown that a contrast between different materials is resolvable. From the experimentally determined reaction rates cross sections for the reactions leading to positron emitters were performed. The data taken in the 3 He experiments were compared those obtained in carbon-ion experiments as well as literature data for proton irradiations. A comparison with the calculations of the simulation program SHIELD-HIT was performed. A collection of cross-section models and the established requirements for a simulation program applicable for in-beam PET are preparing for further work

  20. Study on increasing commercial benefits of 60Co irradiation facilities

    Yang Shuizi; Qi Huanjiang; Xei Tong

    2004-01-01

    Estimating commercial benefits of irradiation facilities adopts commercial benefits coefficient. The effect factors are the utilization rate of irradiation energy (E), the consistency of irradiation facilities (Ci), the utilization rate of time (T), the utilization rate of space, the minimum efficient adsorption dose (Dmin), the irradiation adsorption dose uriformity (U), the sale (S), the running cost (C) et. al, and E, Ci, S, C are main in all factors. (authors)

  1. Study on the cytogenetic activity of freshly irradiated potatoes

    Zajtsev, A.N.; Osipova, I.N.

    1978-01-01

    Cytogenetic activity of potatoes, subjected to gamma irradiation in the dose of 10 Krad, feeding the animals in a day after irradiation, has been investigated. The frequency of chromosomal aberrations in bone marrow cells of mice, who obtained newly irradiated raw or baked potatoes, has no substantial difference from the analogous mutageneity index of mice from the control group. The data obtained are of practical importance when considering the problem of using gamma-irradiated potatoes in the people nourishment

  2. Tritium monitoring in the GCFR sweep gas fuel irradiation capsule BG-10

    Gat, U.; Pruitt, M.E.; Longest, A.W.; Epstein, B.D.

    1980-01-01

    The release of tritium and its transport pathways were studied in a vented, pressure-equalized fuel rod which simulated a fuel rod in a Gas-Cooled Fast Reactor (GCFR). The purpose was to determine the fraction of total tritium production transported via the various pathways and to determine its chemical form (tritiated hydrogen or water). It was concluded that the fuel rod and its effluent venting lines retained low concentrations of HT (or T 2 ) and any HTO (or T 2 O) present. However, the addition of 1% hydrogen to the helium carrier gas quantitatively eluted the tritium from the charcoal trap integral to the fuel rod and from the effluent lines. The chemical composition of the tritium arriving at the monitoring system could be determined by means of converters which convert HT to HTO and vice versa. Ht was the dominant species in the samples measured

  3. Food irradiation studies at the Institute of Nuclear Energy Research, Taiwan, Rep. of China

    Fu, Y.-K.; Tsai, C.-M.; Wu, W.-S.; Chang, M.-S.; Chang, Y.-N.; Shu, S.-L.

    1981-01-01

    The use of radiation to inhibit sprouting of potatoes, onions, gingers and garlic was studied at the Institute of Nuclear Energy Research. The sprout inhibition doses were found to be, 10, 5, 2.5, 7.5 Krads, respectively. Changes in the content of moisture, ash, reducing sugars, total sugars, lipids, proteins, fiber etc. were monitored in various agricultural foodstuffs both with and without γ-irradiation at various doses. Fungicides did not prevent potatoes from decaying at 10 or 25 0 C with or without gamma radiation. Onions treated with any fungicides have significantly more healthy tissues than controls at 10 0 C but not 25 0 C after 30 and 60 days storage, regardless of the presence or absence of gamma radiation. Insect pests have been causing great damage to stored rice in Taiwan. The four most harmful insects are: Sitophilus Zeamais Mostschulsky, Rhyzopertha dominica, Tribolitum custaneum Herbst and Sitotroga cerealella Oliver. Adults, eggs or larvae of these insect pests were irradiated by 60 Co gamma rays. The results show that 40 Krads of gamma-irradiation could completely control these four species of pests in stored rice. (author)

  4. Integrated studies of irradiated Philippine mangoes. Part of coordinated programme in Asian Regional Cooperative Project on Food Irradiation

    Manalo, J.A.

    1985-09-01

    Effects of combined treatment of hot water dip (50 deg. C for 5 min.) and irradiation (0.65 kGy) on technological and sensory qualities of Carabao mangoes were investigated. Mangoes that ripen to the yellow green stage during transport may be subjected to irradiation of combined hot water dip at 50 deg. C for 5 minutes and irradiation at 0.65 kGy. When stored at the low temperature of 12-15 deg. C, shelf life is extended further. Time interval between hot water dip and irradiation must be as short as possible and fruits must be stored at ambient temperature prior to irradiation to prevent discoloration. Shelf life studies show that green fruits subjected to combined treatment and stored at ambient temperature extended shelf life by 6 days, 50% of yellow green mangoes subjected to combined treatment exhibited shelf life extension by four days. Mangoes stored at cold temperature, whether immediately after irradiation or after ripening showed considerable reduction in bacterial decay, regardless of fruit maturity, thus extending their shelf life considerably. Results of sensory evaluation showed no marked differences in color, aroma, appearance, and acceptability were observed by the taste panelists and although controls were always rated higher than the treated samples, scores higher than 5 given to the treated samples showed that they were also generally acceptable

  5. A history of study on safety of irradiated foods (3). Induced radioactivity in irradiated foods

    Miyahara, Makoto

    2006-01-01

    Food irradiation can induce a small amount of radioactivity in the foods. The principal mechanisms of the nuclear reactions are (n, γ), (γ, n), (γ, γ'). The resulting nuclear products were found in irradiated foods were Na-24, P-32, Ca-45, C-11, N-13, and O-15 in the food irradiated by 24 MeV electron beam. The total radioactivity is less than 1/1000 of those of K-40 in the case of electron beams below 10 MeV or X rays below 5 MeV. Package materials affected neutron flux in the foods and enhanced the radioactivity. Electron beam machine produces neutrons and increases the flux in food. IAEA recommend to reduce neutron production in the facility. The safety of irradiated food in the radioactivity field still needs more progress. (author)

  6. EPR studies of gamma-irradiated taurine single crystals

    Bulut, A. E-mail: abulut@samsun.omu.edu.tr; Karabulut, B.; Tapramaz, R.; Koeksal, F

    2000-04-01

    An EPR study of gamma-irradiated taurine [C{sub 2}H{sub 7}NO{sub 3}S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of {sup 32}SO{sup -}{sub 2} and {sup 33}SO{sup -}{sub 2} radicals. The hyperfine values of {sup 33}SO{sup -}{sub 2} radical were used to obtain O-S-O bond angle for both sites.

  7. EPR studies of gamma-irradiated taurine single crystals

    Bulut, A.; Karabulut, B.; Tapramaz, R.; Koeksal, F.

    2000-01-01

    An EPR study of gamma-irradiated taurine [C 2 H 7 NO 3 S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of 32 SO - 2 and 33 SO - 2 radicals. The hyperfine values of 33 SO - 2 radical were used to obtain O-S-O bond angle for both sites

  8. Positron lifetime study of neutron-irradiated molybdenum

    Hinode, Kenji; Tanigawa, Shoichiro; Kumakura, Hiroaki; Doyama, Masao; Shiraishi, Kensuke.

    1978-01-01

    Annealing behavior of fast-neutron-irradiated molybdenum was studied by means of positron lifetime technique. It was found that Stage III annealing can be mainly identified as the vacancy migration process from the detailed analyses of data. The void growth after successive high temperature annealings was clearly detected through the changes of positron lifetime parameters. An attempt to analyse the size distribution of voids from positron lifetime spectra was presented, and discussions on the evaluation of void concentration from positron data are also given. (author)

  9. Preliminary study of killing the larva of plodia interpunella by irradiation

    Wang Jide; Ma Xiaoping

    1994-01-01

    The results of killing the larva of plodia interpunella in the fruit by 60 Co γ-irradiation are described. The lowest effective dose for killing larva by irradiation is ca. 2000 Gy; the effective dose for immediately killing larva is 3000 Gy. The method is simple and easy and also suitable for the study of commercial irradiation of dry-fruit

  10. Positron annihilation and Moessbauer studies of neutron irradiated reactor pressure vessel steels

    Brauer, G.; Matz, W.; Liszkay, L.; Molnar, B.

    1990-11-01

    Positron annihilation (lifetime, Doppler broadening) and Moessbauer studies on unirradiated, neutron irradiated and neutron irradiated plus annealed reactor pressure vessel steels (Soviet type 15Kh2NMFA) are presented. The role of microstructural properties and the formation of irradiation-induced precipitates is discussed. (orig.) [de

  11. Study on prediction model of irradiation embrittlement for reactor pressure vessel steel

    Wang Rongshan; Xu Chaoliang; Huang Ping; Liu Xiangbing; Ren Ai; Chen Jun; Li Chengliang

    2014-01-01

    The study on prediction model of irradiation embrittlement for reactor pres- sure vessel (RPV) steel is an important method for long term operation. According to the deep analysis of the previous prediction models developed worldwide, the drawbacks of these models were given and a new irradiation embrittlement prediction model PMIE-2012 was developed. A corresponding reliability assessment was carried out by irradiation surveillance data. The assessment results show that the PMIE-2012 have a high reliability and accuracy on irradiation embrittlement prediction. (authors)

  12. Economic feasibility study of potato preservation by irradiation in saudi arabia

    Kinsara, A A; Abulfaraj, W H; Mamoon, A M; Kamal, S E [Nuclear Engineering Department, Faculty of Engineering, King Abdulaziz University, Jeddah (Saudi Arabia)

    1997-12-31

    Comprehensive studies were carried out to investigate the economic feasibility of the preservation of potato crop by cobalt-60 gamma irradiation sprout inhibition by potato irradiation was approved by international organization and concerned authorities in many countries. The dose level range authorized for potato sprout inhibition extends from about 80-150 Gy depending on potato variety, time of irradiation after harvest, and post irradiation storage temperature. Sprout inhibition is most effective by irradiation after harvest, and after healing of any inflicted injuries, that when the potatoes are dormant. Irradiation at the recommended doses minimizes storage losses of potatoes that are refrigerated or stored on shelves. Despite the limited data available, an attempt was made to quantify the monetary value of preserving potato by irradiation. With economy scale taken in consideration, potato preservation by irradiation is economically feasible since at the local consumption rates there will be lot of potatoes that ned storage for off season use. 5 tabs.

  13. Study of an automatized experimental device for the irradiation of a radioactive target

    Claverie, G.

    1996-01-01

    In order to solve the enigma of solar neutrinos, a team of physicians of the nuclear research center of Bordeaux-Gradignan and of the center of nuclear spectroscopy and mass spectroscopy of Orsay (France) decided to measure again the cross section of the beryllium-proton nuclear reaction at the lowest possible energies. This measurement requires the design of an automatized experimental device to irradiate in a specific way a beryllium target with an accelerated proton beam. The aim of this work is the study of such a device for an energy range of 800 to 300 KeV. This device comprises a particle multi-detector and a shutter for the irradiation of the target and the counting of the reaction products according to a programmable time sequence. The advantage of this setup is to allow an important bombardment of the target and to ensure its cooling. This device is automatically controlled thanks to a micro-controller, actuators (step motors and electrostatic deflector). It includes some beam diagnosis elements controlled by step motors and a target temperature monitoring system controlling a safety valve. The management of the experiment cell vacuum has led to the design of a vacuum monitor allowing the precise follow up of the vacuum and the control of the safety valves of the device. The nuclear instrumentation necessary to be implemented for this measurement is also presented. (J.S.)

  14. Study of TileCal scintillator irradiation using the minimum bias integrators

    AUTHOR|(INSPIRE)INSPIRE-00387867; The ATLAS collaboration

    2016-01-01

    The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the LHC. It provides precise energy measurements of hadrons, jets, taus and missing transverse energy. The monitoring and calibration of the calorimeter response at each stage of the signal development is done by a movable $^{137}$Cs radioactive source, a laser calibration system and a charge injection system. Moreover, during LHC data taking, an integrator-based readout provides the signals coming from inelastic proton-proton collisions at predominantly low momentum transfer (minimum bias events) and allows monitoring of the instantaneous ATLAS luminosity as well as the response of calorimeter cells. The integrator currents have been used to detect and quantify the effect of TileCal scintillator irradiation using the data taken in 2012 and 2015 that correspond to about 22 fb$^{−1}$ and 4 fb$^{−1}$ of integrated luminosity, respectively. Finally, the response variation for an irradiated cell has been studied comb...

  15. AFM studies on heavy ion irradiated YBCO single crystals

    Lakhani, Archana; Marhas, M.K.; Saravanan, P.; Ganesan, V.; Srinivasan, R.; Kanjilal, D.; Mehta, G.K.; Elizabeth, Suja; Bhat, H.L.

    2000-01-01

    Atomic Force Microscopy (AFM) is extensively used to characterise the surface morphology of high energy ion irradiated single crystals of high temperature superconductor - YBCO. Our earlier systematic studies on thin films of YBCO under high energy and heavy ion irradiation shows clear evidence of ion induced sputtering or erosion, even though the effect is more on the grain boundaries. These earlier results were supported by electrical resistance measurements. In order to understand more clearly, the nature of surface modification at these high energies, AFM studies were carried out on single crystals of YBCO. Single crystals were chosen in order to see the effect on crystallites alone without interference from grain boundaries. 200 MeV gold ions were used for investigation using the facilities available at Nuclear Science Centre, New Delhi. The type of ion and the range of energies were chosen to meet the threshold for electronically mediated defect production. The results are in conformity with our earlier studies and will be described in detail in the context of electronic energy loss mediated sputtering or erosion. (author)

  16. Genetic studies on two soybean cultivars irradiated with gamma rays

    El-Demerdash, H.M.

    2007-01-01

    In the present study, the effect of gamma irradiation was used in two Egyptian soybean cultivars; Giza-22 and Giza-82, to induce genetic variability with doses of 100, 150 and 200 Gy. Some agronomic characters were tested in M1 and M2 generations single plants. Oil and protein contents were measured from the resulted mutants of the two soybean cultivars at M2 generation. Some genetic parameters were estimated on the mean values of M2 generation. The results showed significant differences induced by gamma ray doses in all studied characters, particularly for 200 Gy in M1 generation. Gamma irradiation increased the genetic variability in M2 generation, which helped in selecting some high yielding mutants and some mutants with high oil and protein contents from the two cultivars. The estimated coefficients of phenotypic variance as well as coefficient of genotypic variance were high for seeds weight/plant, pod weight/plant, number of seeds/plant, number of pods/plant and number of nods/plant which showed better scope in genetic improvement. Heritability in the broad sense was high in most of the studied characters. The expected genetic advance (G.A) from selection was high for number of seeds, for number of pods, for pods weight and for mature plant height

  17. Studies on mating competition of irradiated melon flies

    Limohpasmanee, W.

    1994-01-01

    Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

  18. Monitoring, genomic study and control of patulin producing fungi in Korean fruits

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Yun, Hyejung; Kim, Suhyun; Park, Jongchun

    2008-07-01

    This study was intended to apply irradiation technology for the degradation of patulin from apples and apple juices by investigating their physical, mechanical, biological, and pharmacochemical properties in view of potential uses in the bio-industry. The patulin producing fungi was separated from in Korean apples. Totally, 16 morphological types of fungi were isolated from the apples and a patulin producing fungi was identified. The isolated patulin producing fungus was found to a represent species of Penicillium crustosum. The patulin, dissolved in distilled water at a concentration of 50 ppm was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin was remained at apple juice. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependant. The effects of a gamma irradiation on the physiochemical and physical characteristics of apple was investigated during a post-irradiation storage at 4 and 25. Gamma irradiation dose not affect stability of the nutritional contents, functional properties and physical characteristics of apples, especially in the condition of a cold storage after a radiation treatment. The degradation condition characteristics of patulin in apple juice and functional properties of corresponding condition were monitored by response surface methodology (RSM)

  19. Monitoring, genomic study and control of patulin producing fungi in Korean fruits

    Kim, Dongho; Lim, Sangyong; Joe, Minho; Yun, Hyejung [KAERI, Daejeon (Korea, Republic of); Kim, Suhyun [KBSI, Daejeon (Korea, Republic of); Park, Jongchun [Seonam Univ., Asan (Korea, Republic of)

    2008-07-15

    This study was intended to apply irradiation technology for the degradation of patulin from apples and apple juices by investigating their physical, mechanical, biological, and pharmacochemical properties in view of potential uses in the bio-industry. The patulin producing fungi was separated from in Korean apples. Totally, 16 morphological types of fungi were isolated from the apples and a patulin producing fungi was identified. The isolated patulin producing fungus was found to a represent species of Penicillium crustosum. The patulin, dissolved in distilled water at a concentration of 50 ppm was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin was remained at apple juice. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependant. The effects of a gamma irradiation on the physiochemical and physical characteristics of apple was investigated during a post-irradiation storage at 4 and 25. Gamma irradiation dose not affect stability of the nutritional contents, functional properties and physical characteristics of apples, especially in the condition of a cold storage after a radiation treatment. The degradation condition characteristics of patulin in apple juice and functional properties of corresponding condition were monitored by response surface methodology (RSM)

  20. Molecular genetic studies on some irradiated medicinal plants

    Alam el-din, H.F.M

    2007-07-01

    This thesis aimed to study the molecular characterization , the phylogenetic relationships among the four mentha and the three ocimum species and to get some species-specific markers. twenty-one RAPD and 10 ISSR primers were used which showed high polymorphism among the species and detected 150 molecular markers for these genotypes (100 using RAPD and 50 by ISSR-analyses). detection of the phylogenetic relationships based on the three studied systems (RAPD,ISSR and their combined analyses ) indicated that these techniques succeeded in separating the seven species into two main clusters of the two mentha and ocimum genera. SDS-protein patterns characterized the seven genotypes based on presence/ absence and staining intensities of 14 polypeptide bands into two main groups.the effect of four doses of gamma irradiation on eight active components of volatile oils and SDS-protein pattern of stems of mentha viridis indicated that low levels of gamma irradiation could improve the value of some active components of medicinal plants such as menthol in mentha viridis.

  1. Electron spin resonance study of radicals in irradiated polyethylene

    Fujimura, Takashi

    1979-02-01

    In order to elucidate radiation effect in polyethylene, the nature and behavior of radicals produced in polyethylene and the model compound of polyethylene irradiated at 77 0 K were studied by using electron spin resonance. The structure of radical pairs, which are composed of two radicals produced very closely each other, was investigated in drawn polyethylene and the single crystal of n-eicosane. The radical pairs of intrachain type and interchain type were found in polyethylene and n-eicosane respectively. It was suggested that these two types of radical pairs are the precursors of double bonds and crosslinks respectively. The thermal decay reactions of radicals themselves produced in irradiated polyethylene were investigated. It was made clear that the short range distances between two radicals play an important role in the decay reaction of alkyl radicals at low temperatures. The trapping regions of radicals were studied and it was clarified that allyl radicals, which are produced by the reaction of alkyl radicals with double bonds, are trapped both in the crystalline and non-crystalline regions. (author)

  2. Comparative study of the generative organs of tomatoes irradiated at various times of the ontogenesis

    Maulne-Pityinger, O.

    1979-01-01

    The effect of the irradiation of tomato seed and plant on pollen germination and yield formation has been studied. The dose values, the phenological phase of irradiation and, the connection between the probable stimulating dose and yield formation were studied. According to the results the pollen germination ability was slightly increased by treatment with 500-1000 rad, whereas on the influence of 10000 rad it significantly decreased. In the case of plant irradiation, one tenth of the dose used for seed irradiation was applied. The germination percent increased significantly by 100 rad. From the viewpoint of irradiation treatment the three leaf age appeared to be the most advantageous phenological stage. (author)

  3. Study on Laser Welding Process Monitoring Method

    Knag , Heeshin

    2017-01-01

    International audience; In this paper, a study of quality monitoring technology for the laser welding was conducted. The laser welding and the industrial robotic systems were used with robot-based laser welding systems. The laser system used in this study was 1.6 kW fiber laser, while the robot system was Industrial robot (pay-load : 130 kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. The welding joints of steel plate and steel plat...

  4. Study on Laser Welding Process Monitoring Method

    Heeshin Knag

    2016-01-01

    In this paper, a study of quality monitoring technology for the laser welding was conducted. The laser welding and the industrial robotic systems were used with robot-based laser welding systems. The laser system used in this study was 1.6 kW fiber laser, while the robot system was Industrial robot (pay-load : 130 kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. The welding joints of steel plate and steel plate coated with zinc were ...

  5. Morphological studies on the healing process of tooth extraction wounds in whole body irradiated rats

    Hosokawa, Yoichiro

    1991-01-01

    The present studies were performed to investigate the healing process of the tooth extraction wound in whole body irradiated rats and to clarify the effect of irradiation on bone metabolism. One hundred and seven Wistar rats of about 100 g body weight were used and divided into 3 groups. Whole body irradiated rats were given single exposure with a dose of 8 Gy. The region of the left upper molars of local irradiated rats as controls, was exposed to 8 Gy. On the 7th day after irradiation, the left upper first molar of each rat was extracted. The rats were sacrificed at intervals of 1 to 14 days after extraction. Non-irradiated rats were sacrificed at the same intervals after extraction. The maxillary bone including the extraction wound was evaluated, histologically, histometrically and ultrastructurally. From the histological and histometrical findings, the difference of the healing process between non-irradiated rats and locally irradiated rats is not significant. In whole body irradiated rats, the healing process especially in the socket was disturbed. The osteoblastic new bone formation following production of granulation tissue was interfered with. Ultrastructurally, the cytoplasmic organellae were poorly developed in the osteoblast and osteoid formation was reduced in the socket. But periosteal new bone formation was the same as that of the locally irradiated rats. In whole body irradiated rats, the osteoclasts in the interradicular alveolar bone were decreased and have smaller nuclei, compared with non-irradiated and locally irradiated rats. Histometrically, the amount of bone loss was decreased in whole body irradiated rats. Ultrastructurally, the cyoplasmic organellae and ruffled border were poorly developed in the osteoclasts of whole body irradiated rats. The findings suggested that irradiation induced cytological changes not only in osteoblasts but in osteoclasts and these changes resulted in the delayed healing of extraction wound. (author) 106 refs

  6. Morphological studies on the healing process of tooth extraction wounds in whole body irradiated rats

    Hosokawa, Yoichiro (Hokkaido Univ., Sapporo (Japan). School of Dentistry)

    1991-06-01

    The present studies were performed to investigate the healing process of the tooth extraction wound in whole body irradiated rats and to clarify the effect of irradiation on bone metabolism. One hundred and seven Wistar rats of about 100 g body weight were used and divided into 3 groups. Whole body irradiated rats were given single exposure with a dose of 8 Gy. The region of the left upper molars of local irradiated rats as controls, was exposed to 8 Gy. On the 7th day after irradiation, the left upper first molar of each rat was extracted. The rats were sacrificed at intervals of 1 to 14 days after extraction. Non-irradiated rats were sacrificed at the same intervals after extraction. The maxillary bone including the extraction wound was evaluated, histologically, histometrically and ultrastructurally. From the histological and histometrical findings, the difference of the healing process between non-irradiated rats and locally irradiated rats is not significant. In whole body irradiated rats, the healing process especially in the socket was disturbed. The osteoblastic new bone formation following production of granulation tissue was interfered with. Ultrastructurally, the cytoplasmic organellae were poorly developed in the osteoblast and osteoid formation was reduced in the socket. But periosteal new bone formation was the same as that of the locally irradiated rats. In whole body irradiated rats, the osteoclasts in the interradicular alveolar bone were decreased and have smaller nuclei, compared with non-irradiated and locally irradiated rats. Histometrically, the amount of bone loss was decreased in whole body irradiated rats. Ultrastructurally, the cyoplasmic organellae and ruffled border were poorly developed in the osteoclasts of whole body irradiated rats. The findings suggested that irradiation induced cytological changes not only in osteoblasts but in osteoclasts and these changes resulted in the delayed healing of extraction wound. (author) 106 refs.

  7. Ion-irradiation studies of cascade damage in metals

    Averback, R.S.

    1982-03-01

    Ion-irradiation studies of the fundamental aspects of cascade damage in metals are reviewed. The emphasis of these studies has been the determination of the primary state of damage (i.e. the arrangement of atoms in the cascade region prior to thermal migration of defects). Progress has been made towards understanding the damage function (i.e. the number of Frenkel pairs produced as a function of primary recoil atom energy), the spatial configuration of vacancies and interstitials in the cascade and the cascade-induced mixing of atoms. It is concluded for these studies that the agitation of the lattice in the vicinity of energetic displacement cascades stimulates the defect motion and that such thermal spike motion induces recombination and clustering of Frenkel defects. 9 figures

  8. Dosimetry study for electron beam irradiation in radiation processing

    Sunaga, Hiromi; Haruyama, Yasuyuki; Takizawa, Haruki; Kojima, Takuji; Yotsumoto, Keiichi

    1995-01-01

    For certain critical applications such as medical device sterilization and food irradiation, accurate calibration of electron energy and absorbed dose is required to assure the quality of irradiated products. To meet this requirement, TRCRE, JAERI has carried out research and development on high dose radiation dosimetry for electron beams in the energy range used in radiation processing (0.15 - 3.0 MeV). JAERI has developed a simultaneous electron beam energy and dosimeter calibration system that consist of a total absorption calorimeter, an electron current density meter, and a stacked thin-film dosimeter set. For low energy electrons, where it is important to measure the depth-dose profile in materials with high depth resolution, we studied the feasibility of a method using Gafchromic film dosimeters. This film, which has an 8-μm thick sensitive layer, is combined with a stepped array of absorber films of the same thickness to produce a high-resolution depth-dose profile on the Gafchromic film. The depth-dose profile obtained in this manner has about five times greater resolution than conventional radiochromic film dosimetry. (author)

  9. Kr ion irradiation study of the depleted-uranium alloys

    Gan, J.; Keiser, D. D.; Miller, B. D.; Kirk, M. A.; Rest, J.; Allen, T. R.; Wachs, D. M.

    2010-12-01

    Fuel development for the reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium nuclear fuels that can be employed to replace existing high enrichment uranium fuels currently used in some research reactors throughout the world. For dispersion type fuels, radiation stability of the fuel-cladding interaction product has a strong impact on fuel performance. Three depleted-uranium alloys are cast for the radiation stability studies of the fuel-cladding interaction product using Kr ion irradiation to investigate radiation damage from fission products. SEM analysis indicates the presence of the phases of interest: U(Al, Si) 3, (U, Mo)(Al, Si) 3, UMo 2Al 20, U 6Mo 4Al 43 and UAl 4. Irradiations of TEM disc samples were conducted with 500 keV Kr ions at 200 °C to ion doses up to 2.5 × 10 19 ions/m 2 (˜10 dpa) with an Kr ion flux of 10 16 ions/m 2/s (˜4.0 × 10 -3 dpa/s). Microstructural evolution of the phases relevant to fuel-cladding interaction products was investigated using transmission electron microscopy.

  10. Kr ion irradiation study of the depleted-uranium alloys

    Gan, J., E-mail: Jian.Gan@inl.go [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Keiser, D.D. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Miller, B.D. [University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706 (United States); Kirk, M.A.; Rest, J. [Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL 60439 (United States); Allen, T.R. [University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706 (United States); Wachs, D.M. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2010-12-01

    Fuel development for the reduced enrichment research and test reactor (RERTR) program is tasked with the development of new low enrichment uranium nuclear fuels that can be employed to replace existing high enrichment uranium fuels currently used in some research reactors throughout the world. For dispersion type fuels, radiation stability of the fuel-cladding interaction product has a strong impact on fuel performance. Three depleted-uranium alloys are cast for the radiation stability studies of the fuel-cladding interaction product using Kr ion irradiation to investigate radiation damage from fission products. SEM analysis indicates the presence of the phases of interest: U(Al, Si){sub 3}, (U, Mo)(Al, Si){sub 3}, UMo{sub 2}Al{sub 20}, U{sub 6}Mo{sub 4}Al{sub 43} and UAl{sub 4}. Irradiations of TEM disc samples were conducted with 500 keV Kr ions at 200 {sup o}C to ion doses up to 2.5 x 10{sup 19} ions/m{sup 2} ({approx}10 dpa) with an Kr ion flux of 10{sup 16} ions/m{sup 2}/s ({approx}4.0 x 10{sup -3} dpa/s). Microstructural evolution of the phases relevant to fuel-cladding interaction products was investigated using transmission electron microscopy.

  11. Study of Irradiation Effect onto Uranium silicide Fuel

    Suparjo

    1998-01-01

    The irradiation effect onto the U 3 Si-Al and U 3 Si 2 -Al dispersion type of fuel element has been studied. The fuel material performs swelling during irradiation due to boehmite (Al 2 O 3 (H 2 O)) formation in which might occurs inside the meat and on the cladding surface, the interaction between the fuel and aluminium matrix that produce U(Al,Si) 3 phase, and the formation of fission gas bubble inside the fuel. At a constant fission density, the U 3 Si-Al fuel swelling is higher than that of U 3 Si 2 -Al fuel. The swellings of both fuels increase with the increasing of fission density. The difference of swelling behavior was caused by formation of large bubble gases generated from fission product of U 3 Si fuel and distributed non-uniformly over all of fuel zone. On the other hand, the U 3 Si 2 fission produced small bubble gases, and those were uniformly distributed. The growth rate of fission gas bubble in the U 3 Si fuel has shown high diffusivity, transformation into amorph material and thus decrease its mechanical strength

  12. Study of chemical and physical properties of irradiated Guar Gum

    Hussein, H. A. S.

    2012-07-01

    This study was carried out to evaluate the effect of different gamma radiation doses to decontamination of micro-organisms present in Guar Gum powder. As well as to study the effect of radiation on the chemical and physical properties of the carbohydrate components of the Gum's material. Two types of samples were used in this study (powder and liquid). All samples were collected from commercially available Guar Gum (G G), which were obtained from the company (Sudanese Guar Gum ltd). Samples putted in polyethylene tightly closed container, then irradiated by applying different doses (2.5, 5, 7.5, 10, 20,30,40,and 50 kGy) from Co-60 source at room temperature in air. And take zero kGy as control. Irradiated powder samples of (2.5, 5, 7.5, 10 kGy) were investigated for contamination by using growth media agar and the result showed that 2.5 kGy is appropriate dose to remove the contamination of the samples. And then analyzed using fourier transform infrared (FTTR) x-ray fluorescence (X RF) and spectroscopy. The FTIR spectroscopy results suggested that there were no major chemical functional group transformation during irradiation. No change occurs by using low dose as 2.5 kGy. Also evaluation impact of radiation on liquid Samples (Aqueous solutions prepared in tow concentration of 1% and 5% wv that is by exposing the samples to the same dose of gamma rays) the effect of irradiation on it were investigated by using ultra violet spectroscopy ( UV.Vis), results showed that low dose has steeply effect in solutions specially in low concentration, it was more pronoun than that in high concentration, high dose has made change similar to that it made in powder. Also for both concentrations of liquid samples and for solutions made of irradiated powder pH measured and viscosity which used in investigations of molecular weight of liquid and powder, comparing the results of impact in the form of powder with the results of effects in the solutions found that the effects of

  13. Performance studies under high irradiation and ageing properties of resistive bulk Micromegas chambers at the new CERN Gamma Irradiation Facility

    Sidiropoulou, O.; Gonzalez, B. Alvarez; Bianco, M.; Farina, E.M.; Iengo, P.; Longo, L.; Pfeiffer, D.; Wotschack, J.

    2017-01-01

    Resistive bulk Micromegas chambers, produced at CERN, have been installed at the new CERN Gamma Irradiation Facility (GIF++) in order to study the effects of ageing and to evaluate the detector behaviour under high irradiation. The chambers have an active area of 10×10 cm 2 , strip pitch of 400 μm and an amplification gap of 128 μm. We present the detector performance as a function of the background rate of up to 20 MHz/cm 2 . - Highlights: • Small-size resistive bulk Micromegas detectors have been exposed to the new GIF++. • 9 months irradiation to γ up to 20 Mhz/cm 2 . 0.09 C/cm 2 collected integrated charge. • Νo degradation of the detector performance was observed. • Muon tracks successfully reconstructed up to 68 kHz/cm 2 gamma background. • Higher background rates will be studied in the coming months.

  14. Food preservation by irradiation. V.- Economic study of the spanish potatoe market and preservation feasibility by irradiation

    Rivas, A.; Garcia de Mateos, A.; Ortin Sune, N.; Val Cob, M. del

    1967-01-01

    A study of the spanish potatoe market is carried o nt in order to know the possibilities of preservation by irradiation. The study is initiated with a recompilation of statistical data on the production and consumption of potatoes by regions and seasons. Last years losses are then estimated. (Author) 9 refs

  15. Comparative studies in the cellular immunostimulation by whole body irradiation

    Dietz, R.; Schwarze, G.

    1992-01-01

    The effect of the cellular immune response by total body irradiation was investigated. The transplant survival (skin grafts) was determined as immune parameter. Donors were colony bred Wistar rats and recipients were colony bred Sprague Dawley rats. The investigations were carried out with irradiated rats and with rats irradiated after thymectomy and/or adrenalectomy as well as with animals without irradiation. A single total-body irradiation (1 and 2 Gy) was administered. The skin graft survival in irradiated rats was significant shorter (radiogenic immunostimulation) than in unirradiated rats; there were no significant differences between the operated (thymectomy and/or adrenalectomy) and not operated animals. Including precedent examinations this radiogenic immunostimulation is caused by relativly selective inactivation of T-suppressor cells. (orig.) [de

  16. Food irradiation is safe: Half a century of studies

    Roberts, Peter B.

    2014-01-01

    The potential benefits of food irradiation are yet to be realized due to slow progress in the commercialization of the technology. Processing food with ionizing radiation has encountered several barriers, one of which is the belief that consumers will not purchase irradiated food and a consequent caution among food retailers and producers. There is sufficient evidence that consumers will purchase irradiated foods when offered at retail in contrast to the data from many surveys of general public opinion. Communicating this evidence to food retailers and producers is essential if a major barrier to a greater use of the technology is to be overcome. - Highlights: • Food irradiation is safe and can benefit food safety, security and trade. • Commercial use remains limited. • The food trade tends to believe consumers will not buy irradiated food. • There is good evidence that consumers buy irradiated food when it is offered. • Demonstrating this evidence to industry is vital for commercial success

  17. Techno-economic studies on transportable moving-bed onion irradiator

    Krishnamurthy, K.; Sharma, K.S.S.; Deshmukh, V.P.; Bongirwar, D.R.; Nair, K.V.V.; Patil, K.B.

    1984-01-01

    The paper presents the optimisation studies and the design features of a transportable irradiator evolved to demonstrate the techno-economic advantage of the irradiation process at village level. A brief outline is also given of the computer programme generated and employed to optimise the source-target configuration based on a narrow plane source moving-bed irradiation concept that aimed at achieving a simplified product handling system and cost effective design of the biological shield and controls for the irradiator. The engineering features of the irradiator along with a summary of the analysis of the economics of the application of the process are also given. (author)

  18. Study of the effects of a prenatal or postnatal irradiation of 150 rads in adult rats

    Coffigny, H.; Pasquier, C.

    Pregnant females and newborn rats were exposed to a gamma irradiation of 150 rads. The stage of gestation at the time of irradiation varied from 14 to 21 days. The newborn rats were irradiated at 0, 1 and 2 days of age. The effect of irradiation of foetus and newborn rats depends on the age of the animal at the time of irradiation. This effect was specially important at the beginning of the foetal life. Neonatal mortality, growth of body weight and adult brain development were investigated. A modification of germ cell radiosensitivity during the period studied, was emphasized [fr

  19. Irradiation preservation study on Beijing roast duck by low dose

    Weiguo, Wang; Yongbao, Gu; Fengmei, Li [Beijing Normal Univ., BJ (China). Inst. of Low Energy Nuclear Physics; and others

    1989-02-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as {gamma}-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome.

  20. Irradiation preservation study on Beijing roast duck by low dose

    Wang Weiguo; Gu Yongbao; Li Fengmei

    1989-01-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as γ-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome

  1. Study on irradiation of freshening ginseng and toxicity test

    Wang Ziwen; Xu Dechun; Yang Wanqi

    1991-01-01

    The ginsengs irradiated by 1 or 2 kGy of γ-rays have been stored for 6 months under room temperature. Its freshening rates was 86.67% and 88.33% respectively. The saponin content was maintained. The irradiated ginsengs had the vigour of sap fully and beautiful colour. Therefore they can be stored much longer for sell. The toxicity test showed that there was no toxicity for irradiated ginsengs

  2. Pre- and post-irradiation fading effect for LiF:Mg,Ti and LiF:Mg,Cu,P materials used in routine monitoring

    Carinou, E.; Askounis, P.; Dimitropoulou, F.; Kiranos, G.; Kyrgiakou, H.; Nirgianaki, E.; Papadomarkaki, E.; Kamenopoulou, V.

    2011-01-01

    LiF is a well-known thermoluminescent (TL) material used in individual monitoring, and its fading characteristics have been studied for years. In the present study, the fading characteristics (for a period of 150 d) of various commercial LiF materials with different dopants have been evaluated. The materials used in the study are those used in routine procedures by the Personal Dosimetry Dept. of Greek Atomic Energy Commission and in particular, LiF:Mg,Ti (MTS-N, TL Poland), LiF:Mg,Cu,P (MCP-N, TL Poland), LiF:Mg,Cu,P (MCP-Ns, thin active layer detector, TL Poland) and LiF:Mg,Cu,P (TLD100H, Harshaw). The study showed that there is a sensitivity loss in signal of up to 20 % for the MTS-N material for a 150-d period in the pre-irradiation fading phase. The MCP-N has a stable behaviour in the pre-irradiation fading phase, but this also depends on the readout system. As far as the post-irradiation fading effect is concerned, a decrease of up to 20 % for the MTS-N material is observed for the same time period. On the other hand, the LiF:Mg,Cu,P material presents a stable behaviour within ±5 %. These results show that the fading effect is different for each material and should be taken into account when estimating doses from dosemeters that are in use for >2 months. (authors)

  3. Pilot-scale studies on the irradiation of Bangladesh onions

    Matin, M.

    1986-01-01

    Two major varieties of onions were irradiated (50-80 Gy) and stored either at ambient temperature (20-37 deg. C) and humidity (70-90% RH) and/or under refrigeration (13-15 deg. C) for nine months. Raw and cooked irradiated onions had higher organoleptic ratings. Consumers found irradiated onions were of superior quality. There were no adverse comments on the sale and quality of irradiated onions purchased at competitive market prices. There were no adverse consumer comments nor negative reaction to purchase at competitive market prices

  4. Physicochemical studies for detection of irradiated dry date fruits

    Farag, S.E.A.; El-Salhy, F.T.; Nassef, A.E.; El-beltagy, A.E.; Moharram, H.A.

    2005-01-01

    The kinetic of the water absorption properties of a selected varieties from the Egyptian dry date fruits were carried out. Sakoti, shamia bida, sokaria, candela and malkabee varieties were used to get an idea about their water absorption properties. Malkabee variety was selected for irradiation at different doses of 0.5, 1, 2, 3, 4 and 5 KGy. In order to obtain a fast, reliable and easy techniques for detecting irradiated dates, several physico-chemical and ultrastructural properties were elucidated in this investigation. Regarding to water absorption, the statistical analysis of the water absorption data revealed that, the amount of water absorption (g water/g dry solid) was decreased with increasing the irradiation doses. This phenomena was confirmed when SEM technique was applied, since irradiation caused shrinkage and reduction in the inner cells. The colour indices were measured by colour analyzer (hunter colorimeter). An inversely proportional relationship was observed between the hue angle and the progress in the irradiation dose, In contrast, direct proportional relationship is strongly observed when the color combination a/b was measured. From the chemical analysis point of view, it was observed that irradiation lowered the amount of total sugars by enhanced reducing sugars. From elucidating the physico-chemical properties of the irradiation date palm, it is now possible to establish a stainable fast, reliable and cheap detection method that could be used to distinguish between the irradiated and non-irradiated dry date fruits

  5. Experimental study of selective irradiation to the kidneys

    Nishimori, I; Tsuda, N; Moriyama, N; Miyagawa, N; Fuzikawa, K [Nagasaki Univ. (Japan). School of Medicine

    1976-03-01

    In order to examine the effects of a massive irradiation on the kidney, 4,000 R of x-ray was irradiated to both kidneys of rats. Renal atrophy was observed 1, 2 and 3 weeks after the irradiation, and this alteration was severe especially in the left kidney. Light microscopic examination revealed dilatation of the renal tubules, swelling of the tubular epithelial cells, granular degeneration and cylindrialization 1 and 2 weeks after the irradiation. However, there was no remarkable alteration in the glomeruli. Lobulation of the glomeruli appeared in addition to alteration in the renal tubules 3 weeks after the irradiation. Hyalinosis of the glomeruli, degerenation of the renal tubules, cylindrialization, thickening of the vascular wall, fibroid necrosis, and proliferation of the interstitial cells appeared 25 weeks after the irradiation. Electron microscopic examination revealed reduction of the nuclei in the tubular epithelial cells, differentiation and thickening of dense bodies and the basement membrane, dilatation of capillaries and swelling of the endothelial cells 1 week after the irradiation. Obliteration of capillaries of the glomeruli, thickening of the basement membrane, deposit of collagen and swelling of the epithelial cells were observed 25 weeks after the irradiation. Cellular infiltration was observed in the interstitial tissue. The increase of blood pressure, vascular lesion and hyalinosis of the glomeruli, which appeased 25 weeks after the irradiation, are considered to be caused secondarily by an increase of the interstitial cells.

  6. Cyanobacteria, Toxins and Indicators: Field Monitoring,Treatment Facility Monitoring and Treatment Studies

    This presentation is a compilation of harmful algal bloom (HAB) related field monitoring data from the 2015 bloom season, treatment plant monitoring data from the 2013 and 2014 bloom seasons, and bench-scale treatment study data from 2015.

  7. Electron microscopic study of the spilt irradiation effects on the rat parotid ductal cells

    Kim, Sung Soo; Lee, Sang Rae

    1988-01-01

    This study was designed to investigate the effects of split irradiation on the salivary ductal cells, especially on the intercalated cells of the rat parotid glands. For this study, 24 Sprague-Dawley strain rats were irradiated on the head and neck region with two equal split doses of 9 Gy for a 4 hours interval by Co-60 teletherapy unit, Picker's mode l 4M 60. The conditions of irradiation were that field size, dose rate, SSD and depth were 12 X 5 cm, 222 cGy/min, 50 cm and 1 cm, respectively. The experimental animals were sacrificed 1, 2, 3, 6, 12, hours and 1, 3, 7, days after the irradiation and the changes of the irradiated intercalated cells of the parotid glands were examined under light and electron microscope. The results were as follows: 1. By the split irradiation, the degenerative changes of intercalated cells of the parotid glands appeared at 3 hours after irradiation and the most severe cellular degeneration observed at 6 hours after irradiation. The repair processes began from 12 hours after irradiation and have matured progressively. 2. Under electron microscope, loss of nuclear membrane, microvilli and secretory granules, derangement of chromosomes, degeneration of cytoplasm, atrophy or reduction of intracytoplasmic organelles were observed in the intercalated ductal cells after split irradiation. 3. Under light microscope, derangement of ductal cells, widening of cytoplasms and nuclei, hyperchromatism and proliferation of ductal cells were observed in intercalated ducts after split irradiation.

  8. Study of damages by neutron irradiation in lithium aluminates

    Palacios G, O.

    1999-01-01

    Lithium aluminates proposed to the production of tritium in fusion nuclear reactors, due to the thermal stability that they present as well as the behavior of the aluminium to the irradiation. As a neutron flux with profile (≅ 14 Mev) of a fusion reactor is not available. A irradiation experiment was designed in order to know the micro and nano structure damages produced by fast and thermal neutrons in two irradiation positions of the fusion nuclear reactor Triga Mark III: CT (Thermal Column) and SIFCA (System of Irradiation Fixed of Capsules). In this work samples of lithium aluminate were characterized by XRD (X-Ray Diffraction), TEM (Transmission Electron Microscopy) and SEM (Scanning Electron Microscopy). Two samples were prepared by two methods: a) coalition method and b) peroxide method. This characterization comprised original and irradiated samples. The irradiated sample amounted to 4 in total: one for each preparation method and one for each irradiation position. The object of this analysis was to correlate with the received neutron dose the damages suffered by the samples with the neutron irradiation during long periods (440 H), in their micro and nano structure aspects; in order to understand the changes as a function of the irradiation zone (with thermal and fast neutron flux) and the preparation methods of the samples and having as an antecedent the irradiation in SIFCA position by short times (2h). The obtained results are referred to the stability of γ -aluminate phase, under given conditions of irradiation and defined nano structure arrangement. They also refer to the proposals of growth mechanism and nucleation of new phases. The error associated with the measurement of neutron dose is also discussed. (Author)

  9. Experimental study on irradiation injury of the kidneys. II. Cardiovascular changes following renal irradiation

    Tomita, S; Fuzikawa, K; Nishimori, I; Tsuda, N; Miyagawa, N [Nagasaki Univ. (Japan). School of Medicine

    1976-09-01

    In order to investigate irradiation injury of the kidney and effect of injured kidney on the whole body, especially cardiovascular changes, a single kidney was extracted from Wistar female rats and only the remaining kidney was irradiated with a great amount of radiation in 4000 R dose experimentally. After seven weeks of irradiation, atrophy and involution of the highest region of the kidney were found. Histologically, fibrous proliferation of interstice accompanied with atrophy of the renal tubule, and slightly increased nuclei and lobulation of the glomerulus were recognized. After 15 weeks of irradiation, atrophy and involution of the whole kidney were found. Histologically, fibrous proliferation of interstice in the kidney accompanied with a high degree of atrophy of the renal tubule, marked increase and lobulation of mesangium ground substance of the glomerulus and mild hypertrophy of arteriole were recognized. Mild degeneration of myocardium was recognized. In the long-term cases passing 29 and 34 weeks after irradiation, blood pressure just before slaughter rose to 250 mmHg. The kidney showed malignant nephrosclerosis-like lesion, and panarteritis was found in the mesentery and peri-pancreatic artery. In the heart, hypertonic myocardosis was recognized. A rise of blood pressure which was observed in this experiment occurred in circulation degenerations resulted from the secondary hypertrophy of the blood vessels accompanied with fibrous proliferation of the interstice which appeared after degeneration of renal tubule. It was thought that panarteritis of cardiovascular system of the whole body, especially mesentery and peri-pancreatic artery, and fibrinoid degeneration of arteriole of the kidney were due to hypertension and angiopathic factors (non-vasopressor extracts from the injured kidney).

  10. Positron lifetime study of copper irradiated by energetic protons or energetic neutrons

    Howell, R.H.

    1979-03-01

    Positron lifetime measurements of pure copper damaged by irradiation with energetic protons and neutrons are presented. Lifetime determinations of the bulk material and various traps were made, and the dependence of the trapping rate on dose and irradiation energy were investigated. The results from the neutron- and proton-irradiated samples point to the existence of traps with similar but distinct lifetime parameters, not varying greatly from values reported in deformation studies. Also, a trap with long lifetime is seen for some proton irradiations, but is never seen for the neutron irradiations. The trapping rate of the short-lifetime trap is a linear function of dose for proton-irradiated samples and nearly so for the neutron irradiation. 1 figure

  11. Biophysical study of mice blood after whole body irradiation

    Saad El Din, Alsha A.; Desouky, Omar S.; El Behay, Amin Z.; El Sayed, Anwar A.

    1996-05-01

    The immediate of whole body fractionated doses of 137Cs gamma rays totalling 13 Gy on mice as well as the late effects of accumulative dose of 10 Gy (8 days after exposure) were studied. Changes due to gamma irradiation in hemoglobin conductivity and buffer capacity indicate the appearance of hydrophobic groups and changes in hydrophilic/hydrophobic ratio. These changes demonstrate different degrees of unfolding and refolding of the hemoglobin molecule. The viscosity coefficient of hemoglobin is found to increase at fractionated doses of 7 and 13 Gy. Such effect seems to be due to aggregation of the protein part of hemoglobin. The fractionated dose of 13 Gy causes changes in the electronic state of oxyhemoglobin indicated by an increase in methemoglobin which reduces biological activity.

  12. Grafting study of polysulfone polymeric membranes by gamma ray irradiation

    Furtado Filho, Acacio A.M.; Gomes, Ailton de S.

    2011-01-01

    Radiation-induced grafting of styrene poli sulfone films were investigated by simultaneous method in solution using gamma-ray from a radio nuclide 60 Co source. The gamma-ray energy of high intensity induced breaking of chemical bonds leading to free radical formation. The radical start a conventional polymerization sequence comparable with that obtained with a chemical catalyst acting as initiator. The effects of grafting conditions such as irradiation total dose, dose rate and addition of cross linking agent, were studied by means of morphology analysis, thermal degradation and crystallinity. After the grafting reaction, the membranes were submitted to an exhaustive extraction with solvent to remove the polystyrene homopolymer formed. The degree of grafting (DOG) was analyzed by percentage of weight increase. As a result, the reaction always follows the same pattern: DOG increases rapidly initially whilst propagation is the main reaction, then more slowly as termination becomes more frequent. (author)

  13. Rheological and microbiological study of flour treated by irradiation

    Laabidi, Othmen

    2007-01-01

    the aim this work is to study the effectiveness of radio treatment and its effect on the conservation of flour and their various parameters (physico-chemical and rheological). The flour has been treated with different doses (0, 0.75, 1.5 and 3 kGy), physico-chemical, rheological, microbiological and sensory analyses were made.The results show that the irradiation as a treatment for decontamination gave a highly effective. Indeed, a dose of 1.5 kGy allows a total destruction of yeasts and molds. Thus, from the point of view physico-chemical, increasing the dose of radiation causes a change in physical and chemical properties and rheological of flour. for the characteristics of bread, increasing the dose of radiation affects the quality of bread. (Author). 38 refs

  14. Antioxidant action in irradiated polypropylene studied by ultraviolet spectroscopy

    Milosavljevic, B.H.; Novakovic, Lj.

    1999-01-01

    Ultraviolet spectrum of 0.2 mm thick film of polypropylene containing 0.5% ORGANOX 1010 showed that in the sample prepared by slow cooling about 15% of the antioxidant reacted during the preparation process. The difference in turbidity between the samples obtained in the slow and the fast cooling process is attributed to the degree of crystallinity, which is in agreement with the DSC data. Very pronounced effects of the oxygen concentration and the degree of crystallinity on antioxidant uptake in irradiated polypropylene films were observed and discussed. It was also shown that a Febetron 707 pulsed electron accelerator is capable of producing both the single pulse dose (50 kGy) and the dose rate (2.5 TGy/s) large enough to enable a comparison of dose rate effects and LET effects in the study of the antioxidant reactions in polypropylene

  15. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes; a food irradiation study on radiation induced stress in vegetable products

    Bergers, W.W.A.

    1980-01-01

    Irradiation is a recent preservation method. With the aid of ionizing radiation microorganisms in food can be killed or specific physiological processes in vegetable products can be influenced.

    In order to study the effects of metabolic radiation stress on quantitative chemical changes in

  16. Quantitative computed tomography bone mineral density measurements in irradiated and non-irradiated minipig alveolar bone: an experimental study.

    Verdonck, H.W.; Meijer, G.J.; Nieman, F.H.; Stoll, C.; Riediger, D.; Baat, C. de

    2008-01-01

    OBJECTIVE: The objective of this study was to analyse the effect of irradiation on bone mineral density (BMD). MATERIALS AND METHODS: All maxillary and mandibular pre-molars and molars of six minipigs were extracted. After a 3-month healing period, the maxilla and mandibles of three minipigs

  17. Progress in the study of reducing food allergenicity by irradiation

    Gu Kefei; Gao Meixu; Li Chunhong; Pan Jiarong

    2006-01-01

    Food allergy becomes an important factor in food safety areas. As one of the methods to cure allergy, reducing food allergenicity by irradiation becomes a hot topic. This article reviewed the present situation and the mechanism of reducing food allergenicity by irradiation. (authors)

  18. Feasibility study and treatment of food by irradiation

    Bouslama, N.

    1996-01-01

    This thesis deals with the over costs of food irradiation compared to the costs of traditional food treatments in Tunisia. Food irradiation techniques imply appropriate facilities and special storage conditions that face producers and consumers to new economic choices. This approach is applied to dates (N.H.)

  19. Studies on effects of γ-ray irradiation on yellow rice wine mellowness and sterilization

    Hua Fenmei; Chen Qiufang

    1994-03-01

    The effects of irradiation dosage, irradiation temperature, different kinds of packing container, vacuous capacity of the container, technology of making wine and storage time on acceleration of yellow rice wine mellowness were studied by sensory evaluation and chemical composition analysis. The results showed low dosage of γ-ray irradiation had accelerated the mellowness of yellow rice wine. The unique flavour of colour, aroma, taste and style were still remained after the wine was irradiated. The hygiene and safety experiments showed the irradiated wine is safe to human health. The optimal temperature during γ-ray irradiation was 30∼40 degree C. The pottery containers were superior to the glass container for the packing container during yellow wine irradiation. The suitable vacuous capacity for a 500 ml glass bottle was 100 ml. The new technology of brewing wine was better than the traditional technology for the quality of irradiated wine. The proper storage time after irradiation was 5∼6 months. The γ-ray irradiation combined at 60 degree C of temperature had good effects on sterilization of raw yellow wine. The quality of irradiated wine was stable, the chemical composition was not changed, and it was still remained the traditional flavour. It is up to the standard of export wine

  20. 10 μ m-thick four-quadrant transmissive silicon photodiodes for beam position monitor application: electrical characterization and gamma irradiation effects

    Rafí, J. M.; Pellegrini, G.; Quirion, D.; Hidalgo, S.; Godignon, P.; Matilla, O.; Juanhuix, J.; Fontserè, A.; Molas, B.; Pothin, D.; Fajardo, P.

    2017-01-01

    Silicon photodiodes are very useful devices as X-ray beam monitors in synchrotron radiation beamlines. Owing to Si absorption, devices thinner than 10 μ m are needed to achieve transmission over 90% for energies above 10 keV . In this work, new segmented four-quadrant diodes for beam alignment purposes are fabricated on both ultrathin (10 μ m-thick) and bulk silicon substrates. Four-quadrant diodes implementing different design parameters as well as auxiliary test structures (single diodes and MOS capacitors) are studied. An extensive electrical characterization, including current-voltage (I-V) and capacitance-voltage (C-V) techniques, is carried out on non-irradiated and gamma-irradiated devices up to 100 Mrad doses. Special attention is devoted to the study of radiation-induced charge build-up in diode interquadrant isolation dielectric, as well as its impact on device interquadrant resistance. Finally, the devices have been characterized with an 8 keV laboratory X-ray source at 108 ph/s and in BL13-XALOC ALBA Synchroton beamline with 1011 ph/s and energies from 6 to 16 keV . Sensitivity, spatial resolution and uniformity of the devices have been evaluated.

  1. Cost/benefit study on date disinfestation by gamma irradiation in Algeria

    Mahlous, M.

    2002-01-01

    To establish the irradiation technology, one must have a holistic approach to the technology of food irradiation in order to assure a maximum utilization rate of the facility. The assumptions in this study are based on a free standing multipurpose irradiation facility, the throughput of which is expressed in t·kGy/year, and the unit cost of the treatment in US $/t·kGy. These values may then be applied for the calculation of the treatment cost of any food commodity, according to the irradiation dose needed. The study showed that irradiation treatment of dates is profitable and that the cost of irradiation does not exceed 1.6% of the selling price of the product. Post harvest losses may be considerably reduced thanks to irradiation treatment. A comparative study between irradiation and cold storage showed that irradiation will cost 30% less than cold storage. This study is completed by an evaluation of consumer acceptance of irradiated food products. (author)

  2. Study of the biochemical indicators of chronic irradiation in rats.

    Szabo, L D; Benko, A B; Gyenge, L; Predmerszky, T

    1976-01-01

    Daily urinary excretion of pseudouridine, creatinine and creatine of chronically irradiated Wistar rats was estimated. The irradiation conditions were: 60Co gamma source, dose-rate 10 rad/day, total dose 200, 400 and 600 rad. Control groups were kept under similar conditions. Urine samples were taken three times after the end of the irradiation period. It was found that: (1) pseudouridine excretion seems more suitable for indicating radiation injury than the creatine/creatinine ratio in chronic irradiation in rats; (ii) there are significant changes in dose dependence of pseudouridine excretion in the post-irradiation period; (iii) a new method for pseudouridine estimation gives closely similar data to those of earlier investigations.

  3. Study of irradiation defects in bismuth by electric transport measurements

    Le Goff, M.

    1984-01-01

    Pure monocrystalline bismuth is irradiated near 4K by electrons of different energies. Irradiation effects are measured by galvanomagnetic properties at low temperature. Frenkel pairs created during irradiation have a strong effect on carrier mobilities. The data are quantitatively analyzed assuming a rigid band model. After irradiation with 1 MeV electrons, each Frankel pair created corresponds to a total charge of 0.14 electrons. This result obtained by magnetoresistance and Hall effect is confirmed by Shubnikov-de Haas experiments. There is a linear variation between the excess carrier density (p-n) and the Frenkel pair concentration. The more important step of annealing is observed around 40-50 K. This step is attributed to interstitial migration. Resistivity presents a minimum at low temperature after irradiation with electrons of energy over 1.3 MeV. This is explained by virtual bound levels near the Fermi level. The Kondo effect bound to magnetic defects is discussed [fr

  4. Proton irradiation studies on Al and Al5083 alloy

    Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

    2017-10-01

    The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

  5. Studies on the preservation of food by gamma irradiation

    Kim, S.K.; Umeda, K.

    1979-01-01

    This work was conducted to investigate the effects of ionizing radiation on the preservation of potato. The Irish Cobbler potato tubers were irradiated at the doses of 7 krad and 15 krad of gamma ray of Co-60 at room temperature. When the potato tubers were stored under various conditions, the freshness and preservability of irradiated potato tubers were remarkably extended by 20, June. The results of this work are summarized as follows: The potato tubers applied with 15 krad of gamma ray were observed freshness without any shrinkage and defects. The potato tubers of control rotted and sprouted completely on 3, March. All tubers of them were cured at 7 0 C and relative humidity of 90% for a month before irradiation and they were treated at 18-20 0 C and RH 80% for 2 weeks after irradiation. They were stored at the above mentioned conditions. Reducing Sugar content of irradiated potato tubers was negligibly changed such as non-irradiated potato tubers along with an extended storage period, when they, as pre-and post-irradiation, were stored at 7 0 C and RH 90%. If they were treated at 18-20 0 C and RH 80% for 2 weeks after irradiation, reducing sugar content of the potato tubers was temporarily increased and then it was decreased as much as the former. As the result of microscopic test for the wound-peridom formation of potato tubers, the dark brown cork layer of wounded tuber of control was perfectly built up at about 2 weeks of the post wound, and starch particles have disappeared almost. The cork layer of irradiated potato tuber was formed at 3-4 weeks after wounded and also starch particles were not watched. The layers irradiated potato was observed the same as cork layer of sound potato. (author)

  6. Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

    Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

    2017-01-01

    Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

  7. Systematic irradiation studies and quality assurance of silicon strip sensors for the CBM Silicon Tracking System

    Larionov, Pavel

    2016-10-01

    The Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) is designed to investigate the phase diagram of strongly interacting matter at neutron star core densities under laboratory conditions. This work is a contribution to the development of the main tracking detector of the CBM experiment - the Silicon Tracking System (STS), designed to provide the tracking and the momentum information for charged particles in a high multiplicity environment. The STS will be composed of about 900 highly segmented double-sided silicon strip sensors and is expected to face a harsh radiation environment up to 1 x 10 14 cm -2 in 1 MeV neutron equivalent fluence after several years of operation. The two most limiting factors of the successful operation of the system are the radiation damage and the quality of produced silicon sensors. It is therefore of importance to ensure both the radiation tolerance of the STS sensors and their quality during the production phase. The first part of this work details the investigation of the radiation tolerance of the STS sensors. Series of irradiations of miniature sensors as well as full-size prototype sensors were performed with reactor neutrons and 23 MeV protons to a broad range of fluences, up to 2 x 10 14 n eq /cm 2 . The evolution of the main sensor characteristics (leakage current, full depletion voltage and charge collection) was extensively studied both as a function of accumulated fluence and time after irradiation. In particular, charge collection measurements of miniature sensors demonstrated the ability of the sensors to yield approx. 90% to 95% of the signal after irradiation up to the lifetime fluence, depending on the readout side. First results on the charge collection performance of irradiated full-size prototype sensors have been obtained, serving as an input data for further final signal-to-noise evaluation in the whole readout chain. Operational stability of these

  8. Systematic irradiation studies and quality assurance of silicon strip sensors for the CBM Silicon Tracking System

    Larionov, Pavel

    2016-10-15

    The Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) is designed to investigate the phase diagram of strongly interacting matter at neutron star core densities under laboratory conditions. This work is a contribution to the development of the main tracking detector of the CBM experiment - the Silicon Tracking System (STS), designed to provide the tracking and the momentum information for charged particles in a high multiplicity environment. The STS will be composed of about 900 highly segmented double-sided silicon strip sensors and is expected to face a harsh radiation environment up to 1 x 10{sup 14} cm{sup -2} in 1 MeV neutron equivalent fluence after several years of operation. The two most limiting factors of the successful operation of the system are the radiation damage and the quality of produced silicon sensors. It is therefore of importance to ensure both the radiation tolerance of the STS sensors and their quality during the production phase. The first part of this work details the investigation of the radiation tolerance of the STS sensors. Series of irradiations of miniature sensors as well as full-size prototype sensors were performed with reactor neutrons and 23 MeV protons to a broad range of fluences, up to 2 x 10{sup 14} n{sub eq}/cm{sup 2}. The evolution of the main sensor characteristics (leakage current, full depletion voltage and charge collection) was extensively studied both as a function of accumulated fluence and time after irradiation. In particular, charge collection measurements of miniature sensors demonstrated the ability of the sensors to yield approx. 90% to 95% of the signal after irradiation up to the lifetime fluence, depending on the readout side. First results on the charge collection performance of irradiated full-size prototype sensors have been obtained, serving as an input data for further final signal-to-noise evaluation in the whole readout chain. Operational

  9. The field-irradiator gamma study: Fourteen years of irradiation of the boreal forest

    Amiro, B.D.; Hawkins, J.L.; Laverock, M.J.; Sheppard, S.C.

    1996-01-01

    The Field-Irradiator Gamma (FIG) project is a long-term experiment on the response of boreal forest vegetation to chronic ionizing radiation. The forest was irradiated from 1973 to 1986 by a 370 TBq point source of 137 Cs placed at a height of 20 m. The forest is now in the recovery phase. The irradiated forest included several different community types, and each of these was affected differently by the radiation stress. New vegetation zones have now been created because of the selective tolerance to radiation along a gradient from background dose rates to a maximum of 65 mGy h -1 . One of the easiest measured indicators of the radiation stress has been photographic documentation of changes in forest communities over time. Measured changes in species composition and the decrease in tree canopy cover at dose rates >2 Gy h -1 have also helped quantify radiation effects. Indicators such as trends in annual growth rings have been less satisfactory. Our experiment suggests that there are no visible impacts at chronic dose rates less than 0.1 mGy h -1 and the threshold for effects likely is between 0.1 and 1 mGy h -1 . The experimental area has been preserved to allow measurements of long-term recovery of the site

  10. Pristine and γ-irradiated halloysite reinforced epoxy nanocomposites - Insight study

    Saif, Muhammad Jawwad; Naveed, Muhammad; Zia, Khalid Mahmood; Asif, Muhammad

    2016-10-01

    The present study focuses on development of epoxy system reinforced with naturally occurring halloysite nanotubes (HNTs). A comparative study is presented describing the performance of pristine and γ-irradiated HNTs in an epoxy matrix. The γ-irradiation treatment was used for structural modification of natural pristine HNTs under air sealed environment at different absorbed doses and subsequently these irradiated HNTs were incorporated in epoxy resin with various wt% loadings. The consequences of γ-irradiation on HNTs were studied by FTIR and X-ray diffraction analysis (XRD) in terms of changes in functional groups and crystalline characteristics. An improvement is observed in mechanical properties and crack resistance of composites reinforced with γ-irradiated HNTs. The irradiated HNTs imparted an improved flexural and tensile strength/modulus along with better thermal performance.

  11. Progresses in studies on 2-alkylcyclobutanones in irradiated lipid-containing foods

    Zhang Haiwei; Ha Yiming; Wang Feng

    2007-01-01

    When foods are irradiated, the free fatty acids and triacylglycerides in the food are decomposed to 2-alkylcyclobutanones (2-ACBs), which have been one of the focuses in food irradiation studies since they were dis- covered in irradiated lipid-containing foods. As specific markers, 2-ACBs could be used to detect irradiated food. The production and stability of 2-ACBs are affected strongly by the irradiation does and temperature and preservation conditions, etc. On the other hand, potential health hazard assessments of 2-ACBs have been studied extensively. Re- cent progresses in 2-ACBs detecting methods from irradiated food, toxicological studies on 2-ACBs, and factors affecting production and stability of 2-ACBs are reviewed in this paper. (authors)

  12. Studies on sprout inhibition of onions by gamma irradiation

    Thomas, P.; Srirangarajan, A.N.; Limaye, S.P.

    1975-01-01

    Sprout inhibition of onions by gamma irradiation was found to be influenced by the physiological state of the bulbs at the time of irradiation, radiation dose and the storage temperature after irradiation. Sprouting was minimal during storage at ambient temperature (26 to 32 0 C) while exposure to low temperature (4 to 20 0 C) or widely fluctuating diernal temperature (20 0 C min to 30 0 C max) accelerated it. Six to nine Krad inhibited sprouting during storage under the above conditions only if the bulbs were irradiated within a fortnight of harvest when they were in the dormant state. Twenty-five Krad caused a transient stimulation of sprouting regardless of the time of irradiation while 6 to 12 Krad only stimulated sprouting when the time interval between harvest and irradiation exceeded three weeks. Irradiation at all dose levels cause discoloration of the growth centre, the extent of which was minimal in bulbs exposed to low doses soon after harvest and in those stored at ambient temperature. (author)

  13. Studies on the preservation of Korean Ginseng by irradiation

    Sung, H.S.; Park, M.H.; Lee, K.S.; Cho, H.O.

    1982-01-01

    In order to evaluate the feasibility for the sterilization of Korean red and white ginseng powder by irradiation, red and white ginseng powder (120 mesh) was irradiated by 0.1, 0.3, 0.5, 0.7, 1.0 and 2.0 Mrad with 60 Co irradiator (dose rate: 4000 rad/h). Extraction rate of crude saponins by buthanol and by 50% ethanol were slightly increased according to the irradiation dose (buthanol ex. 1.7%, 50% ethanol ex. 2.6%) at 1.0 Mrad irradiation. There are no remarkable changes in HPLC patterns of crude saponins by radiation. It was found that irradiation up to 1 Mrad on Korean ginseng products have no significant effect on proximate component, reducing sugar and amino nitrogen of ginseng powder and on the color density of ginseng extract with 50% ethanol. Irradiation up to 1 Mrad could be utilized for the sterilization of Korean ginseng powder without changes of physicochemical properties. (Author)

  14. Study of I11-conditioning of Linac stereotactic irradiation subspaces using singular values decomposition analysis

    Platoni, K.; Lefkopoulos, D.; Grandjean, P.; Schlienger, M.

    1999-01-01

    A Linac sterotactic irradiation space is characterized by different angular separations of beams because of the geometry of the stereotactic irradiation. The regions of the stereotactic space characterized by low angular separations are one of the causes of ill-conditioning of the stereotactic irradiation inverse problem. The singular value decomposition (SVD) is a powerful mathematical analysis that permits the measurement of the ill-conditioning of the stereotactic irradiation problem. This study examines the ill-conditioning of the stereotactic irradiation space, provoked by the different angular separations of beams, using the SVD analysis. We subdivided the maximum irradiation space (MIS: (AA) AP x (AA) RL =180 x 180 ) into irradiation subspaces (ISSs), each characterized by its own angular separation. We studied the influence of ISSs on the SVD analysis and the evolution of the reconstruction quality of well defined three-dimensional dose matrices in each configuration. The more the ISS is characterized by low angular separation the more the condition number and the reconstruction inaccuracy are increased. Based on the above results we created two reduced irradiation spaces (RIS: (AA) AP x (AA) RL =180 x 140 and (AA) AP x (AA) RL =180 x 120 ) and compared the reconstruction quality of the RISs with respect to the MIS. The more an irradiation space is free of low angular separations the more the irradiation space contains useful singular components. (orig.)

  15. Irradiation device

    Suzuki, Toshimitsu.

    1989-01-01

    In an irradiation device for irradiating radiation rays such as electron beams to pharmaceuticals, etc., since the distribution of scanned electron rays was not monitored, the electron beam intensity could be determined only indirectly and irradiation reliability was not satisfactory. In view of the above, a plurality of monitor wires emitting secondary electrons are disposed in the scanning direction near a beam take-out window of a scanning duct, signals from the monitor wires are inputted into a display device such as a cathode ray tube, as well as signals from the monitor wires at the central portion are inputted into counting rate meters to measure the radiation dose as well. Since secondary electrons are emitted when electron beams pass through the monitor wires and the intensity thereof is in proportion with the intensity of incident electron beams, the distribution of the radiation dose can be monitored by measuring the intensity of the emitted secondary electrons. Further, uneven irradiation, etc. can also be monitored to make the radiation of irradiation rays reliable. (N.H.)

  16. Irradiation studies of mallard duck eggs material containing Mirex

    Lane, R.H.; Grodner, R.M.; Graves, J.L.

    1976-01-01

    Eggs containing Mirex (dodecachloropentacyclo[5.3.0.0 2 , 6 .0 3 , 9 .0 4 , 8 ]decane) from mallard ducks (Anas platyrhychos l.), fed diets with the insecticide incorporated at levels of 1 and 100 ppM for 25 weeks, were subjected to ultraviolet (uv) and γ irradiation. Seven derivatives were obtained on photolysis and eight derivatives were obtained from γ irradiation. Irradiation products appeared to be mono and dihydro derivatives of Mirex. Structural assignments for two monohydro derivatives and three dihydro derivatives were made on the basis of retention time and mass spectral data

  17. A disposal centre for irradiated nuclear fuel: conceptual design study

    1980-09-01

    This report describes a conceptual design of a disposal centre for irradiated nuclear fuel. The surface facilities consist of plants for the preparation of steel cylinders containing irradiated nuclear fuel immobilized in lead, shaft headframe buildings, and all necessary support facilities. The undergound disposal vault is located on one level at a depth of 1000 metres. The cylinders containing the irradiated fuel are emplaced on a one-metre thick layer of backfill material and then completely covered with backfill. All surface and subsurface facilities are described, operations and schedules are summarized, and cost estimates and manpower requirements are given. (auth)

  18. A comparative study of the hydrolysis of gamma irradiated lignocelluloses

    E. Betiku

    2009-06-01

    Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis and softwood (Triplochiton scleroxylon were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p < 0.05, hardwood was hydrolysed significantly better compared to the softwood.

  19. Studies on safety and efficiency of gamma-irradiated ginseng

    Kwon, Joong Ho; Cho, Han Ok; Byun, Myung Wo; Kim, Suc Won; Yang, Jae Seong; Yoo, Young Soo; Jin, Joon Ha; Park, Soon Chul

    1991-09-01

    Gamma irradiation was applied to the biological quality improvement and preservation of white ginseng which has problems in a hygienic quality and storage stability. The current phosphine treatment showed no influence on microorganisms contaminated even though it was very useful for disinfestation of the sample, while 5 kGy irradiation effectively controlled the biological quality of the stored sample, with minimal effects on the quality parameters of white ginseng. Thus, it is concluded that gamma irradiation at a range of 5 kGy can be an alternative method of chemical fumigants provided air-tight packaging excluding recontamination is used for the stored product. (Author)

  20. Study on cytotoxicities induced by alpha particle irradiation combined with NNK treatment

    Li Ping; Yang Zhihua; Pan Xiujie; Cao Zhenshan; Mi Na; Chen Zhongmin; Liu Gang; Wei Han; Li Huiyin; Zhu Maoxiang

    2006-01-01

    Objective: To investigate cytotoxicities of alpha-particle irradiation combined with NNK treatment. Methods: Exponentially growing immortalized human bronchial epithelial cells were divided into normal control group (NC), alpha particle irradiation group (α), NNK administration group (NNK), NNK administration (100 μg/ml) followed by alpha particle irradiation group (NNK + α), and alphaparticle irradiation followed by NNK administration (100 μg/ml) group (α + NNK). Cell survival fractions were measured by cloning rate of low-density plating cell. Ethidium bromide and 2', 7'-dichlorofluorescein, fluorescent products of the membrane-permeable dyes hydroethine and 2', 7'-dichloroflurescindiacetate were used to monitor the inarticulate reactive oxygen species (ROS) . Damage to membrane permeability was evaluated through testing LDH activity in medium. Results: In the groups exposed to both alpha particles and NNK, the survival rates were significantly lower than that of the groups administrated with the same dose of alpha particles or NNK alone. The levels of intracellular ROS and the activity of LDH in medium were significantly higher than that of the groups administrated with the same dose of alpha particles or NNK alone. Subtracted the NNK effect, the survival rates of the groups received both alpha particle irradiation and NNK treatment were significantly lower than that of alpha particle irradiated only group. However, the intracellular ROS level and the activity of LDH in medium were significantly higher than that of alpha-particle irradiated only group. In addition, the survival rates of the cells in groups exposed to alpha particle irradiation followed by NNK administration were significantly lower than that of cells treated with NNK administration followed by alpha particle irradiation. Conclusions: Alpha particle irradiation and NNK administration had synergisticity in cytotoxicity, and furthermore different schedules of the administration resulted in

  1. Performance studies of the vibration wire monitor on the test stand with low energy electron beam

    Okabe, Kota; Yoshimoto, Masahiro; Kinsho, Michikazu

    2015-01-01

    In the high intensity proton accelerator as the Japan Proton Accelerator Research Complex (J-PARC) accelerators, serious radiation and residual dose is induced by a small beam loss such a beam halo. Therefore, diagnostics of the beam halo formation is one of the most important issues to control the beam loss. For the beam halo monitor, the vibration wire monitor (VWM) has a potential for investigating the beam halo and weak beam scanning. The VWM has a wide dynamic range, high resolution and the VWM is not susceptible to secondary electrons and electric noises. We have studied the VWM features as a new beam-halo monitor on the test stand with low energy electron gun. The frequency shift of the irradiated vibration wire was confirmed about wire material and the electron beam profile measured by using the VWM was consistent with the results of the Faraday cup measurement. Also we calculated a temperature distribution on the vibration wire which is irradiated by the electron beam with the numerical simulation. The simulations have been fairly successful in reproducing the transient of the irradiated vibration wire frequency measured by test stand experiments. In this paper, we will report a result of performance evaluation for the VWM on the test stands and discuss the VWM for beam halo diagnostic. (author)

  2. Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

    Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

    2008-04-15

    This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions.

  3. Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

    Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

    2008-04-01

    This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions

  4. Preparation of Tritium from irradiated lithium compounds (study)

    1989-01-01

    The aim of the present study is the selection of a certain scheme for release, collection, measurement and analysis of Tritium as produced in Lithium compounds (Li 2 O, LiOH, Li 2 CO 3 LiF and some Lithium alloys) in accordance with the 6 Li(n, α)T reaction. Tritium technology is of vital concern to power reactor programmes as well as to fusion technology. Meanwhile the fields of activity include, tritium generation and mangement in fission and fusion reactors; enviromental studies, release modeling HT/HTO conversion and dose assessments, absorption/ deabsorption, monitoring and plant design; research and development, labeling, compatibility and physical chemical properties

  5. Experience with a pilot plant for the irradiation of sewage sludge: Bacteriological and parasitological studies after irradiation

    Wizigmann, I.; Wuersching, F.

    1975-01-01

    Comparative bacteriological studies of sewage sludge in a sewage plant have demonstrated that mechanical-biological sewage treatment reduced the total bacterial count and those of Enterococces by 2 log and the Enterobacteriaceae by 3-4 log. Frequently Salmonella could be isolated from sewage sludge. A further reduction of viable micro-organisms could be achieved by irradiation of sewage sludge ( 60 Co, gamma-radiation, 260 krad, 210 min). This reduction amounted to an average of 2 log with Enterococces and total bacterial count, and to 5 log with Enterobacteriaceae. Out of 40 samples investigated after irradiation, two contained Salmonella. The hygienic effects of the irradiation unit were demonstrated by means of a model experiment with bacterial pure cultures. Micro-organisms of different species as well as strains of the same species differ in their sensitivity to irradiation. Parasitological experiments with eggs of Ascaris suum were carried out to test the inhibitory or killing ability of the gamma rays on the developing stages of parasites

  6. Kinetics of the radicals induced in gamma irradiated sulfafurazole: an EPR study

    Colak, S.; Korkmaz, M.

    2004-01-01

    The spectroscopic and kinetic features of the radiolytic intermediates produced in gamma irradiated sulfafurazole (SFZ) were investigated at different temperatures in the dose range 5-50 kGy using EPR and IR techniques. The imodiation produced two species (A, B) in SFZ. The heights of the peaks were used to monitor the temperature, time dependent and kinetic features of the radical species contributing to the EPR spectrum. The applicability of EPR technique for monitoring radiosterilization of SFZ is discussed. The radiation yield of solid SFZ was found to be very low (G=0.16), and basing on this it was concluded that SFZ and SFZ containing drugs can be safely sterilized by radiation. The EPR data were used to characterize the contributing radicals produced in gamma irradiated SFZ. No definite difference was observed between unirradiated and irradiated IR spectra of SFZ. (orig.)

  7. Modelling infrared temperature measurements: implications for laser irradiation and cryogen cooling studies

    Choi, B.; Pearce, J.A.; Welch, A.J.

    2000-01-01

    The use of thermographic techniques has increased as infrared detector technology has evolved and improved. For laser-tissue interactions, thermal cameras have been used to monitor the thermal response of tissue to pulsed and continuous wave irradiation. It is important to note that the temperature indicated by the thermal camera may not be equal to the actual surface temperature. It is crucial to understand the limitations of using thermal cameras to measure temperature during laser irradiation of tissue. The goal of this study was to demonstrate the potential difference between measured and actual surface temperatures in a quantitative fashion using a 1D finite difference model. Three ablation models and one cryogen spray cooling simulation were adapted from the literature, and predictions of radiometric temperature measurements were calculated. In general, (a) steep superficial temperature gradients, with a surface peak, resulted in an underestimation of the actual surface temperature, (b) steep superficial temperature gradients, with a subsurface peak, resulted in an overestimation, and (c) small gradients led to a relatively accurate temperature estimate. (author)

  8. Study On Irradiated Vietnam Java Rambutan Fruit Which Was Postharvested Treatment To Prolong The Shelflife For Export Purposes

    Nguyen Thuy Khanh; Nguyen Thi Ly; Doan Thi The; Cao Van Chung; Nguyen Van Phong

    2014-01-01

    The research - Study on irradiated Vietnam Java rambutan fruit which was postharvested treatment to prolong the shelflife for export purposes - was conducted at Research and Development Center for Radiation Technology and Southern Horticultural Research Institute for 12 months. On the one hand, the theme was to study the effects of low-dose radiation in the range (200-500 Gy) combined with two types of packaging: carton boxes and carton boxes + PE perforated cover 0.5% of the area bags. After 13 days monitoring in 13 o C, RH= 85-90% the results showed that Java rambutan fruit which was packed in carton boxes combined PE bags then irradiated at 300 Gy dose could limit the browning pericarp, dehydration through the rate of browning, browning level and the percentage of weight loss. Irradiated ramtuban also remains their pulp quality when testing the soluble solids, the titratable acidity and the ascorbic acid content. Irradiation did not affect the cell structure of pericarp and pulp by investigating the total ion leakage. On the other hand, the topics also examined the influence of some postharvest handling and low-dose radiation on Java rambutan. The results showed that pre-irradiation processing: hot water treatment at 43 o C in 6 minute, dipping in cloruacalxi 0.4% + citric acid 0.5% solution in 3 minutes, packed in carton boxes + PE bags and irradiated at 300 Gy dose capable of maintaining the quality which extends the shelflife of Java rambutan more 4 days when kept under conditions of 13 o C, RH= 85-90%. (author)

  9. Study on the irradiation port for wide spread use of carbon cancer therapy

    Komori, Masataka; Yonai, Shunsuke; Kanai, Tatsuaki

    2006-01-01

    A compact irradiation port for wide spread use of carbon radiotherapy is designed. The port length will be reduced to 5.5 m, which equal to half-length of Heavy Ion Medical Accelerator in Chiba (HIMAC). The broad beam method will be used to produce an irradiation field up to 220 mm in diameter and 250 mm in depth. We propose an amplitude-modulation wobbler method, so called spiral wobbler method, to produce the large irradiation field using a small radius beam. The system has an advantage that the residual range at an iso-center is longer than that produced by a conventional wobbler-scatterer method. An accurate dose estimation system will be introduced instead of measuring a calibration factor of dose monitor for each patient. In this project, we verify the design of the irradiation port and the dose estimation system. (author)

  10. An experimental study on the change of bone mineral metabolism after irradiation

    Chin, Hae Yun; Lee, Sang Rae

    1988-01-01

    Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The bone densitometry and bone scintigraphy and valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absorptiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before presentation of the osteoradionecrosis can be developed at low dose irradiation and confirmed by bone densitometry, bone scanning, and histopathology.

  11. Physic-chemical Study of Starch Extracted from Irradiated Corn Flour

    Pozo Sanchez, R. del; Alvarez Gil, M.

    1986-01-01

    The effects of gamma irradiation on starch extracted from irradiated samples of corn flour were studied in the range 0,6 kGy-1,0 kGy. Amylographic properties, solubility and swelling powder of starch samples were determined immediately after irradiation and at 75 days storage at environment conditions (16 0 C-31 0 C, 55%-97% H.R.). Diffraction patterns of crystalline starch were also obtained by X-rays. Gelatinization temperature, swelling powder and diffraction patterns did not change upon irradiation, but a decrease in viscosity and an increase in starch solubility were observed within the dose-range and storage time studied. (author)

  12. Systematic Study of the PbWO4 Crystal Short Term Instalibity Under Irradiation

    Annenkov, Alexander; Chipaux, Rémi; Drobychev, Gleb; Fedorov, Andrey; Géléoc, Marie; Golubev, Nikolai; Korzhik, Mikhail; Lecoq, Paul; Ligun, A B; Missevitch, Oleg; Pavlenko, V B; Peigneux, Jean-Pierre; Singovsky, Alexander

    1997-01-01

    The effect of the irradiation on the lead tungstate ( PWO) scintillator properties has been studied at different irradiation facilities. Lead tungstate crystals grown with the tuning of oxides content in the melt to the stoichiometry of pure sheelite or sheelite-like type crystals and doped with heterovalent, trivalent and pentavalent impurities have been studied in order to optimize their resistance to irradiation. A combination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallisation, and a destruction or compensation of the point structure defects has been used to minimize the short-term instability of PWO parameters under irradiation.

  13. Wholesomeness studies on irradiated foods. Past and future research within the Soviet Union

    Zaytsev, A.N.; Shillinger, Yu.I.; Kamaldinova, Z.M.

    1975-11-01

    The concept of wholesomeness is based on the absence of induced radioactivity, conservation of the nutritive value of food, and absence of toxicological or mutagenic effects. The possible occurrence of Clostridium botulinum toxin in irradiated fish products is discussed. Evaluation of the nutritive value of irradiated food is discussed with regard to proteins and vitamins. Toxicity and mutagenicity studies are described. Feeding studies on the wholesomeness of irradiated food were conducted in the Soviet Union using potatoes, grain, dried fruits, meat, poultry, and fish. The need for further investigations on the biological value of irradiated foods is pointed out. (HLW)

  14. Synthetic activity of rat blood lymphocytes under acute and continuous gamma-irradiation - fluorescent microspectral study

    Karnaukhova, N.A.; Sergiyevich, L.A.; Aksenova, G.Y.; Karnaukhov, V.N.

    1999-01-01

    The effects of different doses of acute and continuous gamma-irradiation on the synthetic activity of rat blood lymphocytes stained with acridine orange were studied by fluorescent microspectrometry. Male rats were exposed to acute gamma-irradiation with doses of 7.5, 4 and 3 Gy, or to continuous irradiation with dose rates of 14.4, 2.1, 1.1 and 0.43 cGy/day, respectively. The changes of the synthetic activity of blood lymphocytes occurred in three main stages after acute gamma-irradiation and in four stages under continuous irradiation. The stages reflect the processes of depression and activation of the immune system under irradiation. Essential differences between the acute and continuous effects were observed in the first stage. After acute gamma-irradiation, the synthetic activity decreased sharply, indicating the predominant contribution of the damaging effect of irradiation, whereas under continuous irradiation, as a result of the stimulatory effect of low-dose irradiation, the synthetic activity increased during the first stage. (orig.)

  15. Researches, development and characterization of dosimetric materials for monitoring in irradiation processes with high doses

    Galante, Ana Maria Sisti

    2003-01-01

    Dosimetric materials that can be produced in Brazil with material acquired in the national market to replace the imported dosimeters used in radiation processing were developed in this work. Mixtures of potassium nitrate and sensitizers compounds as manganese dioxide, barium nitrate and potassium bromide were prepared in the pellet form. Dosimetric characteristics such as dose-response useful range, sensitivity, environmental conditions and dose rate influences were evaluated in 60 Co gamma radiation fields. Dyed polymethylmethacrylate detectors were also produced and its dosimetric characteristics were evaluated. The main characteristics evaluated in this case were: dose response useful range sensitivity, environmental conditions, dose rate influences and radiation energy dependence in gamma radiation fields and accelerated electrons beam of 0.8 to 1.5 MeV. The applied analytic technique was spectrophotometry. The calibration was performed in the irradiation facilities belonging to IPEN and certified by the International Atomic Energy Agency by means of the program IDAS (International Dose Assurance Service ) using the Fricke dosimeter. The mixture of potassium nitrate and manganese dioxide presented the best results and a wide dose range between 200 and 600 kGy. The response of the developed polymethylmethacrylate detectors are similar to the imported detectors and the dose range is characteristic to each detector and depends on the dye added in its formulation. (author)

  16. An ESR study on the detection of irradiated red lentil

    Ercan, I.; Eken, M.

    2001-01-01

    The purpose of this work is to investigate in detail detection of irradiated red lentil. In this way, red lentil powder was analysed by using Bruker EMX ESR spectrometer before and after irradiation between the doses 1-9 kGy at ambient conditions. It was observed that seeds of non-irradiated and irradiated red lentil have a signal having six lines due to Mn''+''2 content. However hull of the red lentil has a single line whose origin is still unknown. Besides, this signal has superposed with the radiation induced one. It was also found that the intensity of radiation induced signal was decreased logarithmically in time, and the change in the intensity was minimal at low doses

  17. Microbiological studies for the detection of irradiated food

    Abd-Elbary, N.A.

    2001-01-01

    the exposure of food to ionizing radiation is being progressively used in many countries to inactivate food pathogens, to eradicate pests, and to extend shelf life, thereby contributing to a safer and more plentiful food supply. to ensure free consumer choice, irradiated food will be labeled as such, and to enforce labeling, analytical methods to detect the irradiation treatment in the food product itself are desirable, in particular, there is a need for simple and rapid screening methods for the control of irradiated food.this investigation has been carried out in an effect to design reliable methods for detecting whether or not a food has been irradiated . attempts have been made to apply microbiological and biological form measurement

  18. Study on some chemical changes in irradiated pepper and parsley

    Josimovic, L.

    1983-01-01

    The effect of ionizing radiation on some water soluble components (carbohydrates, carbonyl compounds) of pepper and parsley, as well as on piperine in pepper and chlorophyll in parsley has been investigated. The irradiation of parsley with doses as high as 5 Mrad does not bring about any distinct qualitative and quantitative changes. In irradiated pepper qualitative changes were also not observed, but quantitative changes were measured even for doses lower than 1 Mrad. However, piperine in pepper is quite resistant against radiation. (author)

  19. Study on some chemical changes in irradiated pepper and parsley

    Josimovic, L [Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia)

    1983-05-01

    The effect of ionizing radiation on some water soluble components (carbohydrates, carbonyl compounds) of pepper and parsley, as well as on piperine in pepper and chlorophyll in parsley has been investigated. The irradiation of parsley with doses as high as 5 Mrad does not bring about any distinct qualitative and quantitative changes. In irradiated pepper qualitative changes were also not observed, but quantitative changes were measured even for doses lower than 1 Mrad. However, piperine in pepper is quite resistant against radiation.

  20. Post-radiation nephritis. Study of the renal consequences of splenic irradiation for lymphoma

    Le Bourgeois, J.P.; Godefroy, D.; Di Paolo, M.; Parmentier, C.; Tubiana, M.

    1975-01-01

    The left kidney consequences of splenic irradiation in 40 patients with lymphomas were studied. The renal work-up performed before irradiation and every six months afterwards includes: blood pressure, biological tests, IV P and 179 Hg neohydrine renal scan. Computer scan data processing showed a partial disfunction of left kidney in 16 patients with 18 month-follow up. Renal disfunction appeared within 8 to 10 months following spleen irradiation. During that period no clinical or radiological abnormalities were observed [fr

  1. Study of the Effect of Swelling on Irradiation Assisted Stress Corrosion Cracking

    Teysseyre, Sebastien Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    This report describes the methodology used to study the effect of swelling on the crack growth rate of an irradiation-assisted stress corrosion crack that is propagating in highly irradiated stainless steel 304 material irradiated to 33 dpa in the Experimental Breeder Reactor-II. The material selection, specimens design, experimental apparatus and processes are described. The results of the current test are presented.

  2. Histological and autoradiographic changes in locally irradiated lymph nodes (an experimental study on rabbits)

    Kett, K.; Csere, T.; Lukacs, L.; Szilagyi, K.; Illenyi, L.

    1979-01-01

    The authors studied the local effect of 3000 Rxl X-ray irradiation on the popliteal lymph nodes of rabbits. Beside the morpho-histological description autoradiography was performed after injection of H 3 -thymidine in the afferent lymphatic of the irradiated knee node. The main finding is the appearence of newly-formed germinal centers between the 6-10 days after irradiation. (orig.) [de

  3. Study of irradiation effects in austenitic stainless steels

    Etienne, A. [GPM UMR CNRS 6634, Universite et INSA de Rouen (France); Material Department, University of California, Santa Barbara (United States); Pareige, P.; Radiguet, B. [GPM UMR CNRS 6634, Universite et INSA de Rouen (France); Cunningham, N.J.; Odette, G.O. [Material Department, University of California, Santa Barbara (United States); Pokor, C. [EDF RD, departement MMC, site des Renardieres, Moret-sur-Loing (France)

    2011-07-01

    Chemical analyses using Atom Probe Tomography were performed on a bolt made of cold worked 316 austenitic stainless steel, extracted from the internal structures of a pressurized water reactor after seventeen years of reactor service. The irradiation temperature of these samples was 633 K and the irradiation dose was estimated to 12 dpa. These analyses have shown that neutron irradiation has a strong effect on the intragranular distribution of solute atoms. A very high number density (6.10{sup 23} m{sup -3}) of Ni-Si enriched and Cr-Fe depleted clusters was detected after irradiation. In order to bring complementary experimental results and to determine the mechanism of formation of these Ni-Si nano-clusters, Fe{sup 5+} ion irradiations have been performed on a 316 austenitic stainless steel. As after neutron irradiation, the formation of solute enriched features is observed. Linear features and two kinds of clusters, rounded and torus shaped, are present. Considering that solute enriched features are probably formed by radiation induced segregation on point defect sinks, these different shapes are due to the nature of the sinks where segregation occurs. (authors)

  4. Mechanical properties of irradiated nanowires – A molecular dynamics study

    Figueroa, Emilio [Grupo de NanoMateriales, Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla, 653 Santiago (Chile); Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Tramontina, Diego [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, 5500 Mendoza (Argentina); Instituto de Bioingeniería, Universidad de Mendoza, 5500 Mendoza (Argentina); Gutiérrez, Gonzalo, E-mail: gonzalo@fisica.ciencias.uchile.cl [Grupo de NanoMateriales, Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla, 653 Santiago (Chile); Bringa, Eduardo [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, 5500 Mendoza (Argentina)

    2015-12-15

    In this work we study, by means of molecular dynamics simulation, the change in the mechanical properties of a gold nanowire with pre-existing radiation damage. The gold nanowire is used as a simple model for a nanofoam, made of connected nanowires. Radiation damage by keV ions leads to the formation of a stacking fault tetrahedron (SFT), and this defect leads to a reduced plastic threshold, as expected, when the nanowire is subjected to tension. We quantify dislocation and twin density during the deformation, and find that the early activation of the SFT as a dislocation source leads to reduced dislocation densities compared to the case without radiation damage. In addition, we observed a total destruction of the SFT, as opposed to a recent simulation study where it was postulated that SFTs might act as self-generating dislocation sources. The flow stress at large deformation is also found to be slightly larger for the irradiated case, in agreement with recent experiments. - Highlights: • Stacking Fault Tetrahedra (SFT) formation proceeds by cascades, containing typically a vacancy cluster and interstitials. • Applied tension leads to the destruction of the SFT, in contrast to a recently reported case of a SFT which soften the NW. • After the initial dislocation activity, strength is controlled by a few surviving dislocations.

  5. Study of natural diamond detector spectrometric properties under neutron irradiation

    Alekseyev, A B; Kaschuck, Y; Krasilnikov, A; Portnov, D; Tugarinov, S

    2002-01-01

    Natural diamond detector (NDD) performance was studied up to a neutron fluence of 10 sup 1 sup 5 neutron/cm sup 2. The variations of the NDD spectrometric response to incident alpha-particles from sup 2 sup 4 sup 1 Am source after exposure to fast neutron fluences up to 3x10 sup 1 sup 6 n/cm sup 2 were examined. No significant variations up to the level of 10 sup 1 sup 4 n/cm sup 2 were observed. Degradation of charge collection efficiency at higher fluences is reported. No remarkable increase of the NDD leakage current and count rate change had been observed up to a neutron fluence of 3x10 sup 1 sup 6 n/cm sup 2. The charge collection efficiency variations of neutron irradiated diamond spectrometer were studied ex situ under gamma-rays, beta-radiation and visible light excitation. Charge collection efficiency restoration up to 75% level and the NDD performance stabilization by extrinsic low-intensity visible light (550 nm

  6. Studies on the chronic effect of lower dose level irradiation

    Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

    1982-01-01

    This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  7. Pristine and γ-irradiated halloysite reinforced epoxy nanocomposites – Insight study

    Saif, Muhammad Jawwad; Naveed, Muhammad; Zia, Khalid Mahmood; Asif, Muhammad

    2016-01-01

    The present study focuses on development of epoxy system reinforced with naturally occurring halloysite nanotubes (HNTs). A comparative study is presented describing the performance of pristine and γ-irradiated HNTs in an epoxy matrix. The γ-irradiation treatment was used for structural modification of natural pristine HNTs under air sealed environment at different absorbed doses and subsequently these irradiated HNTs were incorporated in epoxy resin with various wt% loadings. The consequences of γ-irradiation on HNTs were studied by FTIR and X-ray diffraction analysis (XRD) in terms of changes in functional groups and crystalline characteristics. An improvement is observed in mechanical properties and crack resistance of composites reinforced with γ-irradiated HNTs. The irradiated HNTs imparted an improved flexural and tensile strength/modulus along with better thermal performance. - Highlights: • The γ-irradiation was used for structural modification of halloysite nanotubes. • Composite materials with irradiated HNTs showed improved mechanical properties. • The γ-irradiation treatment is a promising surface modification method.

  8. An experimental study of the effect of total lymphoid irradiation on the survival of skin allografts

    Park, Charn Il; Han, Man Chung

    1981-01-01

    The study was undertaken to determine the effect of fractionated high-dose total lymphoid irradiation (TLI) on the survival of skin allograft despite major histocompatibility difference. Total lymphoid irradiation is a relatively safe form of radiotherapy, has been used extensively to treat lymphoid malignancies in humans with few side effects. A total of 90 rats, Sprague-Dawley rat as recipient and Wistar rat as donor, were used for the experiment, of which 10 rats were used to determine mixed lymphocyte response (MLR) for antigenic difference and skin allografts was performed in 30 rats given total lymphoid irradiation to assess the immunosuppressive effect of total lymphoid irradiation despite major histocompatibility difference. In addition, the peripheral white blood cell counts and the proportion of lymphocytes was studied in 10 rats given total lymphoid irradiation but no skin graft to determine the effects of bone marrow suppression. The results obtained are summarized as follows. 1. The optimum dose of total lymphoid irradiation was between 1800 rads to 2400 rads. 2. The survival of skin graft on rats given total lymphoid irradiation (23.2 ± 6.0 days) was prolonged about three folds as compared to unirradiated control (8.7 ± 1.3 days). 3. Total lymphoid irradiation resulted in a severe leukopenia with marked lymphopenia, but the count was normal by the end of 3rd week. 4. The study suggests that total lymphoid irradiation is a nonlethal procedure that could be used successfully in animals to transplant allograft across major histocompatibility barriers

  9. An experimental study of the effect of total lymphoid irradiation on the survival of skin allografts

    Park, Charn Il; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1981-06-15

    The study was undertaken to determine the effect of fractionated high-dose total lymphoid irradiation (TLI) on the survival of skin allograft despite major histocompatibility difference. Total lymphoid irradiation is a relatively safe form of radiotherapy, has been used extensively to treat lymphoid malignancies in humans with few side effects. A total of 90 rats, Sprague-Dawley rat as recipient and Wistar rat as donor, were used for the experiment, of which 10 rats were used to determine mixed lymphocyte response (MLR) for antigenic difference and skin allografts was performed in 30 rats given total lymphoid irradiation to assess the immunosuppressive effect of total lymphoid irradiation despite major histocompatibility difference. In addition, the peripheral white blood cell counts and the proportion of lymphocytes was studied in 10 rats given total lymphoid irradiation but no skin graft to determine the effects of bone marrow suppression. The results obtained are summarized as follows. 1. The optimum dose of total lymphoid irradiation was between 1800 rads to 2400 rads. 2. The survival of skin graft on rats given total lymphoid irradiation (23.2 {+-} 6.0 days) was prolonged about three folds as compared to unirradiated control (8.7 {+-} 1.3 days). 3. Total lymphoid irradiation resulted in a severe leukopenia with marked lymphopenia, but the count was normal by the end of 3rd week. 4. The study suggests that total lymphoid irradiation is a nonlethal procedure that could be used successfully in animals to transplant allograft across major histocompatibility barriers.

  10. Radiation damage of polymers studied by positron annihilation. Positron and gamma-ray irradiation effects

    Suzuki, T.; Oki, Y.; Numajiri, M.; Miura, T.; Kondo, K.; Ito, Y.

    1995-01-01

    Positron irradiation effects on polypropylene (PP) have been studied using positron sources ( 22 Na) during positron annihilation (PA) experiments. The irradiation effect was measured by the intensity (I 3 ) of the long-lived component of positronium (Ps). At a low temperature of around 100 K, I 3 for unirradiated PP samples increased due to a termination of the thermal motion of the -CH 3 groups. However, the increase in I 3 for γ-ray irradiated samples was reduced in inverse proportion to the amount of irradiation. Although no increase in I 3 was observed for 1 MGy-irradiated PP with γ-rays, an increase was observed again after a 48 h irradiation by positrons emitted from 22 Na. This may be due to a reconstructing of the polymer chains. (author)

  11. Study on cellular survival adaptive response induced by low dose irradiation of 153Sm

    Zhu Shoupeng; Xiao Dong

    1999-01-01

    The present study engages in determining whether low dose irradiation of 153 Sm could cut down the responsiveness of cellular survival to subsequent high dose exposure of 153 Sm so as to make an inquiry into approach the protective action of adaptive response by second irradiation of 153 Sm. Experimental results indicate that for inductive low dose of radionuclide 153 Sm 3.7 kBq/ml irradiated beforehand to cells has obvious resistant effect in succession after high dose irradiation of 153 Sm 3.7 x 10 2 kBq/ml was observed. Cells exposed to low dose irradiation of 153 Sm become adapted and therefore the subsequent cellular survival rate induced by high dose of 153 Sm is sufficiently higher than high dose of 153 Sm merely. It is evident that cellular survival adaptive response could be induced by pure low dose irradiation of 153 Sm only

  12. Irradiation of carbon nanotubes with carbon projectiles: A molecular dynamics study

    Denton, Cristian D. [Departamento de Fisica Aplicada, Universidad de Alicante, 03080 Alicante (Spain); Heredia-Avalos, Santiago; Moreno-Marin, Juan Carlos [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, 03080 Alicante (Spain)

    2013-04-15

    The irradiation of carbon based nanostructures with ions and electrons has been shown to be an appropriate tool to tailor their properties. The defects induced in the nanostructures during irradiation are able to modify their mechanical and electronic properties. Here we simulate the irradiation of carbon nanotubes with carbon ions using a molecular dynamics code. We use the Tersoff potential joined smoothly to the Universal Ziegler-Biersack-Littmark potential at short distances. We study the number of defects produced after irradiation with a single carbon ion finding a saturation with its energy at {proportional_to} 3 keV. We observe, after continuum irradiation with low energy ions, the formation of bumps in the irradiated region. For larger energy ions we find that the diameter of the nanotube shrinks as shown in previous works. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Study on radiation effect of poly (vinyl alcohol) films irradiated by tritium decay

    Li Hairong; Peng Shuming; Zhou Xiaosong; Yu Mingming; Xia Lidong; Chen Xiaohua; Liang Jianhua

    2014-01-01

    The radiation effect of poly(vinyl alcohol) films used as a kind of gas-barrier material for inertial confinement fusion (ICF) targets was studied under the different conditions of β-ray from tritium decay. The changes of physical and chemical properties of the irradiated material samples were analyzed by FTIR, XRD and AFM. The tritium-hydrogen isotopic exchange reaction of the irradiated samples mainly occurs at C-H bond and the IR absorption peak of C-T bond obviously increases with the irradiation dose. For strong hydrogen bonding interaction, the isotopic exchange reaction doesn't occur at O-H bond. The crystallinity degree and surface morphology of the irradiated samples were changed. The tensile properties of irradiated poly(vinyl alcohol) films were measured by universal material testing machine. The results show that the change trend of mechanical properties is in accordance with the microstructures of the irradiated samples. (authors)

  14. Studies on the effects of gamma irradiation of the black cutworm agrotis ipsilon (HUFN.)

    Ibrahim, S M

    1982-12-31

    The present work deals with the effect of gamma irradiation of the black cutworm, Agrotis ipsilon (Hufn.), special attention was given to the sterilization studies in the hope of promoting the sterile insect technique for the pest control programme. The obtained results could be summarized as follows: Three ages of eggs were irradiated as newly laid egg (6-12 h-old), middle age egg (24-36 h -old) and old egg(60-72 h -old). - The mortality among irradiated eggs was directly related to the increase of irradiation dose or the decrease of the age of treated eggs. - The dose of irradiation required for complete mortality was found to be 5,25 and 70 Krad for newly laid eggs, middle age and old eggs, respectively, - Irradiation of eggs had no effect on the incubation period. 17 tabs., 125 refs.

  15. In Vitro UV-Visible Spectroscopy Study of Yellow Laser Irradiation on Human Blood

    Fuad, Siti Sakinah Mohd; Suardi, N.; Mustafa, I. S.

    2018-04-01

    This experimental study was performed to investigate the effect of low level yellow laser of 589nm wavelength with various laser irradiation time. Human blood samples with random diseases are irradiated with yellow laser of power density of 450mW/cm2 from 10 minutes to 60 minutes at 10 minutes intervals. The morphology of the red blood cell were also observed for different irradiation time. The result shows that there is a significant different in the absorption of light with varying laser irradiation time (p<0.01). The maximum absorption recorded at 40 minutes of irradiation at 340nm peak. Blood smear of the samples reveals that there are observable changes in the morphology of the red blood cell at 40 minutes and 60 minutes of irradiation.

  16. Studies on the effects of gamma irradiation of the black cutworm agrotis ipsilon (HUFN.)

    Ibrahim, S.M.

    1981-01-01

    The present work deals with the effect of gamma irradiation of the black cutworm, Agrotis ipsilon (Hufn.), special attention was given to the sterilization studies in the hope of promoting the sterile insect technique for the pest control programme. The obtained results could be summarized as follows: Three ages of eggs were irradiated as newly laid egg (6-12 h-old), middle age egg (24-36 h -old) and old egg(60-72 h -old). - The mortality among irradiated eggs was directly related to the increase of irradiation dose or the decrease of the age of treated eggs. - The dose of irradiation required for complete mortality was found to be 5,25 and 70 Krad for newly laid eggs, middle age and old eggs, respectively, - Irradiation of eggs had no effect on the incubation period

  17. Vacancy defects in electron irradiated RPV steels studied by positron lifetime

    Moser, P; Li, X H [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee; Akamatsu, M; Van Duysen, J C [Electricite de France (EDF), 77 - Ecuelles (France)

    1994-12-31

    Specimens of French RPV (reactor pressure vessels) steels at different rates of segregation have been irradiated at 150 and 288 deg C with 3 MeV electrons (irradiation dose: 4*10{sup 19} e-/cm{sup 2}). Vacancy defects are studied by positron lifetime measurements before and after irradiation and at each step of isochronal annealing. After 150 deg C irradiation, a recovery step is observed in both specimens, for annealing treatments in the range 220-370 deg C and is attributed to the dissociation of vacancy-impurity complexes. The size of vacancy clusters never overcome 10 empty atomic volumes. If ``fresh`` dislocations are created just before irradiation, big vacancy clusters could be formed. After 288 deg C irradiation, small vacancy cluster of 4-10 empty atomic volumes are observed. (authors). 3 figs., 7 refs.

  18. Study of charge transport in silicon detectors: Non-irradiated and irradiated

    Leroy, C.; Roy, P.; Casse, G.; Glaser, M.; Grigoriev, E.; Lemeilleur, F.

    1999-01-01

    The electrical characteristics of silicon detectors (standard planar float zone and MESA detectors) as a function of the particle fluence can be extracted by the application of a model describing the transport of charge carriers generated in the detectors by ionizing particles. The current pulse response induced by α and β particles in non-irradiated detectors and detectors irradiated up to fluences PHI ∼ 3 · 10 14 particles/cm 2 is reproduced via this model: i) by adding a small n-type region 15 μm deep on the p + side for the detectors at fluences beyond the n to p-type inversion and ii) for the MESA detectors, by considering one additional dead layer of 14 μm (observed experimentally) on each side of the detector, and introducing a second (delayed) component to the current pulse response. For both types of detectors, the model gives mobilities decreasing linearily up to fluences of about 5·10 13 particles/cm 2 and converging, beyond, to saturation values of about 1050 cm 2 /Vs and 450 cm 2 /Vs for electrons and holes, respectively. At a fluence PHI ∼ 10 14 particles/cm 2 (corresponding to about ten years of operation at the CERN-LHC), charge collection deficits of about 14% for β particles, 25% for α particles incident on the front and 35% for α particles incident on the back of the detector are found for both type of detectors

  19. X- and Q-band EPR studies on fine powders of irradiated plants. New approach for detection of their radiation history by using Q-band EPR spectrometry

    Yordanov, Nicola D.; Aleksieva, Katerina

    2004-01-01

    X- and Q-band EPR studies after γ-irradiation of some dry spices and aromatic herbs are reported. Before irradiation all samples show only one singlet line in X-band EPR, whereas the Q-band EPR spectrum of the same samples is a superposition of two individual spectra--one corresponding to the above EPR signal, with an anisotropic spectrum, and a second one consisting of six lines due to the Mn 2+ naturally present in plants. The radiation induced EPR signal due to cellulose free radicals was not detected after γ-irradiation, but only the increase of the natural signal present before the irradiation. The fading kinetic of this EPR signal was monitored in three cases--when samples were kept in plastic bags without any special conditioning after irradiation, when samples were covered with paraffin before irradiation and when samples were dried at 60 deg. C for 1 h before irradiation. The studies show that stability of radiation induced EPR signals decreases in the order of: paraffin covered > heated before irradiation > kept at room conditions. The two EPR spectra in the Q-band--one with radiation dependent intensity and a second due to Mn 2+ , which is radiation independent allow identification of previous radiation treatment based on the fact that Mn 2+ quantity in the sample is constant whereas the quantity of radiation-induced free radicals is temperature dependent. It was found that for irradiated samples the ratio between EPR intensity of the free radicals and that of Mn 2+ before and after heating decreases with 50-60% whereas for non-irradiated samples it is ca. 10-15%

  20. A low temperature cryostat with a refrigerator for studying electron irradiation effects on solids

    Oka, Takashi; Yoshida, Toshio; Kitagawa, Michiharu; Yanai, Masayoshi

    1976-01-01

    A low temperature cryostat with a small cryogenic refrigerator is described which is convenient for studying irradiation effects of the energetic electrons on solids. It allows a sample to be kept about 12 K without irradiation and 15 K under the irradiation at a heating rate of 1.5 w. The sample temperature can be changed up to room temperature by adjusting the power of an attached heater and the pressure of a compressor for the refrigerator. The optical and electrical properties of the sample can be measured under and after irradiation. (auth.)

  1. Crystallographic study of the tempering by irradiation of cold-worked uranium (1960); Etude cristallographique du revenu de l'uranium ecroui par irradiation (1960)

    Tardivon, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    We have studied the phenomenon of the tempering of cold-worked uranium under the action of irradiation by observing the narrowing of the (114) and (133) X-ray diffraction lines as a function of the irradiation level. Simultaneously we have studied the broadening of the 114 line of a recrystallised uranium as a function of the irradiation level. The irradiation temperature was always less than 60 deg. C. Of these two processes, the first is the fastest. We have observed a saturation of the irradiation tempering for a flux of 10{sup 18} n/cm{sup 2}; we deduce from this the dimensions of the volume perturbed by one fission atom to be 10{sup -17} cm{sup 3}. (author) [French] Nous avons etudie le phenomene de revenu par irradiation d'echantillons d'uranium ecroui, en observant l'affinement des raies de diffraction de rayons X (114) et (133) en fonction du taux d'irradiation. Parallelement nous avons etudie l'elargissement de la raie (114 ) d'un uranium recristallise en fonction du taux d'irradiation. La temperature d'irradiation est toujours restee inferieure a 60 deg. C. De ces deux processus le premier est le plus rapide. Nous avons observe une saturation du revenu par irradiation pour un flux de 10{sup 18} n/cm{sup 2}; on en deduit une valeur du volume de la perturbation creee par un atome de fission egale a 10{sup -17} cm{sup 3}. (auteur)

  2. Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI with Brewer measurements at El Arenosillo (Spain – Part 1: Analysis of parameter influence

    M. Antón

    2010-07-01

    Full Text Available The main objective of this study is to compare the erythemal UV irradiance (UVER and spectral UV irradiances (at 305, 310 and 324 nm from the Ozone Monitoring Instrument (OMI onboard NASA EOS/Aura polar sun-synchronous satellite (launched in July 2004, local equator crossing time 01:45 p.m. with ground-based measurements from the Brewer spectrophotometer #150 located at El Arenosillo (South of Spain. The analyzed period comprises more than four years, from October 2004 to December 2008. The effects of several factors (clouds, aerosols and the solar elevation on OMI-Brewer comparisons were analyzed. The proxies used for each factor were: OMI Lambertian Equivalent Reflectivity (LER at 360 nm (clouds, the aerosol optical depth (AOD at 440 nm measured from the ground-based Cimel sun-photometer (http://aeronet.gsfc.nasa.gov, and solar zenith angle (SZA at OMI overpass time. The comparison for all sky conditions reveals positive biases (OMI higher than Brewer 12.3% for UVER, 14.2% for UV irradiance at 305 nm, 10.6% for 310 nm and 8.7% for 324 nm. The OMI-Brewer root mean square error (RMSE is reduced when cloudy cases are removed from the analysis, (e.g., RMSE~20% for all sky conditions and RMSE smaller than 10% for cloud-free conditions. However, the biases remain and even become more significant for the cloud-free cases with respect to all sky conditions. The mentioned overestimation is partially due to aerosol extinction influence. In addition, the differences OMI-Brewer typically decrease with SZA except days with high aerosol loading, when the bias is near constant. The seasonal dependence of the OMI-Brewer difference for cloud-free conditions is driven by aerosol climatology.

    To account for the aerosol effect, a first evaluation in order to compare with previous TOMS results (Antón et al., 2007 was performed. This comparison shows that the OMI bias is between +14% and +19% for

  3. Virus inactivation studies using ion beams, electron and gamma irradiation

    Smolko, Eduardo E. [Laboratorio de Polimeros, Grupo Aplicaciones Industriales, Unidad de Aplicaciones Tecnologicas y Agropecuarias, Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Pbro. Juan Gonzalez y Aragon 15, C.P. B1802AYA Ezeiza, Buenos Aires (Argentina)]. E-mail: smolko@cae.cnea.gov.ar; Lombardo, Jorge H. [Biotech S.A., C.P. 1754 Buenos Aires (Argentina)

    2005-07-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle ({alpha}, d and ss) and {gamma} irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D{sub 37} dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

  4. Virus inactivation studies using ion beams, electron and gamma irradiation

    Smolko, Eduardo E.; Lombardo, Jorge H.

    2005-01-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle (α, d and ss) and γ irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D 37 dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule

  5. Experimental study on intraoperative irradiation for pancreatic cancer

    Ito, Masanao; Asanuma, Yoshihiro; Shibata, Satoshi; Saitoh, Takashi; Koyama, Kenji; Watarai, Jiroh; Masuda, Hirotake

    1993-01-01

    For the treatment of pancreatic head cancer, pancreatoduodenectomy is followed by the intraoperative radiation therapy (IORT). The present dose adopted ranged 20 to 30 Gy; however, the dose is believed to be insufficient for local control of adenocarcinoma cells. In this study, high dose IORT was performed using rabbit, so histological and nutritional changes were evaluated. Rabbits were divided into three groups: 30 Gy, 50 Gy, and 80 Gy. The radiation was performed with electron focusing the base of cranial mesenteric artery (SMA in human). The rabbits were sacrificed at intervals ranging from immediately to 4 years after irradiation. The earliest evidence of histological changes was the loss of endothelium, although it was repaired within 1 week. Fragmentation and reduplication of internal elastic lamina were observed after 1 week; however, the degree was not dose dependent. Damages of the media was observed in 50 and 80 Gy groups. That is, focal degeneration of smooth muscle cell was demonstrated in 50 Gy group and medial necrosis in 80 Gy group. Degeneration of ganglion cells was observed and its severity was dose-dependent. In 80 Gy group, diarrhea occurred more frequently compared with the other groups and body weight loss could not recover within 4 weeks. It is concluded that, since necrosis of aortic media and marked degeneration of ganglion cells are inevitable in 80 Gy group, IORT dose should be increased within 50 Gy. (author)

  6. LPI studies with grazing incidence irradiation at the Nike laser

    Weaver, J.; Kehne, D.; Schmitt, A.; Obenschain, S.; Serlin, V.; Oh, J.; Lehmberg, R.; Seely, J.

    2013-10-01

    Studies of laser plasma instabilities (LPI) at the Nike laser facility at NRL have previously concentrated on planar targets irradiated with their surface normal aligned to the central axis of the laser. Shots with planar targets rotated up 60° to the laser have shown changes in thresholds for the two-plasmon decay instability and stimulated Raman scattering near the quarter critical region. In the case of rotated low-Z targets, spectra were observed to shift to lower wavelength and were substantially stronger in the visible and ultraviolet spectral ranges. The low-Z target data show growth at an incident intensity slightly below (~30%) the threshold values observed at normal incidence. A rapid rise in signal level over the same laser intensities was also observed in the hard x-ray data which serve as an overall indicator of LPI activity. Shots with rotated planar high-Z targets showed that the visible and ultraviolet emissions dropped significantly when compared to low-Z targets in the same geometry. This presentation will include results from upcoming experiments to determine the LPI signal for low-Z, high-Z, and high-Z coated targets at lower laser intensities for several angles of target rotation. Shots with widely separated laser beams are also planned to explore cross beam energy transport at Nike. Work supported by DoE/NNSA.

  7. Gamma irradiation effect on thermo shrink polyethylene tube: Case study

    Naurah Mat Isa; Siti Zulaiha Hairaldin; Mohd Yusof Hamzah; Zulkafli Ghazali

    2010-01-01

    The production technology of heat shrinkable tubes is based on the industrial usage of so-called memory effect in some polymers. Many polymers can be rendered heat shrinkable, particularly polyolefins by introducing crosslinking in the polymer backbone. Heat shrinkable tubes and moulded parts provide mechanical and/or chemical and/or electrical protection. . In this work, irradiation from Co-60 was used to impart crosslinking in polymer and thus modify their mechanical and thermal properties. Heat shrinkable or thermo shrink polyethylene (PE) tube with diameter 6.4 mm was selected to evaluate crosslinking behaviour from the gamma irradiation exposure at 5 different doses (120, 140, 160, 200 and 220 kGy). The gel content (%), tensile properties and thermal behavior and stability of the tubes were measured using DSC and TGA. Tubes irradiated at 140 kGy and 160 kGy showed better tensile properties than those at 120, 200 and 220 kGy doses. Maximum percent of crystallization was observed at 160 kGy and temperature required to crystallize is lower than melting temperature due to changes in molecular orientation. Thermal decomposition of the irradiated tubes occurred at 430-450 degree Celsius which is lower than the unirradiated sample. Gel content analysis for samples irradiated at 180-220 kGy yield up to 30 to 40 % gel fraction. Although the gel fractions are higher than other dose, the samples are expected to experience chain scission presumably due to localized gel formation. (author)

  8. The irradiation studies on diamond-like carbon films

    LiuGuIang; Xie Er Qin

    2002-01-01

    Diamond-like carbon (DLC) films have been deposited on glass substrates using radio-frequency (r.f.) plasma deposition method. gamma-ray, ultraviolet (UV) ray and neutron beam were used to irradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were used to characterize the changing characteristics of SP sup 3 C-H bond and hydrogen content in the films due to the irradiations. It showed that, the damage degrees of the gamma-ray, UV ray and neutron beam on the SP sup 3 C-H bonds are different. Among them, the damage of gamma-ray on the SP sup 3 C-H bond is the weakest. When the irradiation dose of gamma-ray reaches 10x10 sup 4 Gy, the SP sup 3 C-H bond reduces about 50% in number. The square resistance of the films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of the films. Compared with that of the as-deposited one, the IR transmittance of the films irradiated by both gamma-ray and neutron beam is increased to some extent. By using the results on optical...

  9. Study on detection method of irradiated frozen foods and others

    Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio

    1997-01-01

    As detection method of the irradiated foods has history of 20 years, it is said that it has no finished chemical method, which is longed to construct as soon as possible. Up-to-date, many kinds of chemical detection methods have been proposed, the o-tyrosine method thought to be hopeful for the irradiated frozen foods among them was selected to investigate. In this method, phenyl alanine is oxidized with a radical formed on irradiation to tyrosine. The o-tyrosine out of the formed isomers is analyzed quantitatively. When irradiation γ-ray to foods, it was found that amounts of o-tyrosine increased to reach about 2 or 3 times of original amounts. This result was also found to agree with the result reported at the ADMIT conference. Furthermore, possibility of judgement using this method was also shown because of difference on 2 or 3 times of o-tyrosine amounts between unirradiated and over 5 kGy irradiated foods. (G.K.)

  10. A history of study on safety of irradiated foods (2). Clostridium botulinum in irradiated seafood from the reports by the United States Atomic Energy Commission

    Miyahara, Makoto

    2004-01-01

    This review is a part of ''history of study on the wholesomeness of irradiated foods''. Clostridium botulinum in irradiated seafood have been of great concern at the beginning of development of irradiated food. This review describes the studies on Clostridium botulinum by US. Atomic Energy Commission in 1960's with their data and what they recognized it as a risk factor of irradiated foods. In 1999 FAO/IAEA/WHO reported that Clostridium botulinum type A and B spors are apparently the most resistant and thus of great concern in the radiation sterilization of food, whereas the less radiation-resistant type E spores are important in low dose irradiation of foods, particularly fishery products. This review also describes current break-through application by NASA and Canadian irradiator. (author)

  11. Silicon passivation study under low energy electron irradiation conditions

    Cluzel, R.

    2010-01-01

    Backside illuminated thinned CMOS (Complementary Metal Oxide Semiconductor) imaging system is a technology developed to increase the signal to noise ratio and the sensibility of such sensors. This configuration is adapted to the electrons detection from the energy range of [1 - 12 keV]. The impinging electron creates by multiplication several hundreds of secondary electrons close to the surface. A P ++ highly-doped passivation layer of the rear face is required to reduce the secondary electron surface recombination rate. Thanks to the potential barrier induced by the P ++ layer, the passivation layer increases the collected charges number and so the sensor collection gain. The goal of this study is to develop some experimental methods in order to determine the effect of six different passivation processes on the collection gain. Beforehand, the energy profile deposited by an incident electron is studied with the combination of Monte-Carlo simulations and some analytical calculations. The final collection gain model shows that the mirror effect from the passivation layer is a key factor at high energies whereas the passivation layer has to be as thin as possible at low energies. A first experimental setup which consists in irradiating P ++ /N large diodes allows to study the passivation process impacts on the surface recombinations. Thanks to a second setup based on a single event upset directly on thinned CMOS sensor, passivation techniques are discriminated in term of mirror effect and the implied spreading charges. The doping atoms activation laser annealing is turn out to be a multiplication gain inhomogeneity source impacting directly the matrix uniformity. (author)

  12. Studies of deep levels in He+-irradiated silicon

    Schmidt, D.C.; Barbot, J.F.; Blanchard, C.

    1997-01-01

    Deep levels created in n-epitaxial silicon by alpha particle irradiation in the dose range from 10 9 to 10 13 particles/cm 2 have been investigated by the deep level transient spectroscopy technique and capacitance-voltage profiling. Under low fluence irradiation at least four main electron traps have been observed. With further increase in irradiation fluence, two new levels located at E c -0.56 eV and E c -0.64 eV appear on the high-temperature side of the DLTS signal. The slope change observed in the amplitude variations of the singly negative charge state of the divacancy versus the dose takes place when these two new levels appear. This suggests that both are multivacancy-related defects. After annealing at 350 C for 15 min, all electron traps have disappeared. Moreover, no shallow levels are created during the annealing. (orig.)

  13. Ftir study of gamma irradiation LDPE film in air

    Moura, Esperidiana A.B.; Silva, Andre L.A.; Gouvea, Paulo H.D.; Silva, Leonardo G. Andrade e; Gouvea, Douglas; Castro, Ricardo H.R.; Wiebeck, Helio; Kawano, Yoshio

    2003-01-01

    The use of the ionizing radiation for application in plastic packaging, to improve some of properties and for radiation sterilization, has been gaining popularity in the packaging industry. As a consequence of the irradiation, plastic packaging materials can undergo some chemical and physical alterations in their basic function, mainly concerning the protection characteristics. Since changes in physical properties of irradiated packaging films reflect radiation-induced chemical changes in molecular structure, in this work, an investigation was performed by Ftir analysis of LDPE film before and after radiation. Film samples were irradiated with doses between 0 Gy and 100 kGy, at room temperature and in the presence of air. The results showed alterations in the molecular structure, according to the absorbed radiation dose. (author)

  14. Amnesia and vegetative abnormalities after irradiation treatment. A case study

    Christianson, S.Aa. (Departments of Psychology, University of Stockholm (Sweden)); Neppe, V. (Department of Psychology, University of Washington, Seattle (United States)); Hoffman, H. (Department of Psychology, Pacific Neuropsychiatric Institute, University of Washington, Settle (United States))

    1994-11-01

    This paper describes a case of a patient (GX) with a brain tumour in the third ventricle who developed a syndrome of amnestic disorder and vegetative abnormalities (hyperphagia, oligodipsia) after irradiation treatment that followed brain surgery. The patient shows an extremely poor long-term memory on both visually and verbally presented material, and of autobiographical events occurring after the onset of the illness, but some preserved memory functions on short-term memory tasks, semantic memory tasks, and implicit memory tasks. Given the onset of symptoms only after irradiation (a memory deficit in particular), and the non-invasive nature of the surgery, the probable etiology is post-irradiation syndrome. (au) (27 refs.).

  15. Amnesia and vegetative abnormalities after irradiation treatment. A case study

    Christianson, S.Aa.; Neppe, V.; Hoffman, H.

    1994-01-01

    This paper describes a case of a patient (GX) with a brain tumour in the third ventricle who developed a syndrome of amnestic disorder and vegetative abnormalities (hyperphagia, oligodipsia) after irradiation treatment that followed brain surgery. The patient shows an extremely poor long-term memory on both visually and verbally presented material, and of autobiographical events occurring after the onset of the illness, but some preserved memory functions on short-term memory tasks, semantic memory tasks, and implicit memory tasks. Given the onset of symptoms only after irradiation (a memory deficit in particular), and the non-invasive nature of the surgery, the probable etiology is post-irradiation syndrome. (au) (27 refs.)

  16. Education of food irradiation. Study for students majoring in nutrition

    Minami, Ikuko

    2014-01-01

    As the credential for nutrition counselor with professional skills and knowledge for invalids, who also provides the nutrition education for local residence at the administrative organization, the qualification system of registered dietitian has been established in Japan. Additionally, in accordance with the legislation of Basic Act on Food Education and the revision of School Education Law, the Diet and Nutrition Teacher System has established in 2005. Therefore, registered dietitian has been approved to teach at the elementary school or junior high school as a teacher. Since registered dietitian is the educator of the “diet and nutrition,” it is important to provide proper knowledge of food irradiation at the training facility for registered dietitian. This report describes the instruction of food irradiation at the education curriculum of the registered dietitian training course. In addition, questionnaire survey result on the knowledge of food irradiation gathered from newly-enrolled students in the registered dietitian training course will also be reported. (author)

  17. Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

    Ishidate, M. Jr.; Yoshikawa, Kunie; Sofuni, Toshio; Iwahara, Shigeo; Sibuya, Tohru.

    1981-01-01

    The alcohol extracts freshly prepared from gamma-irradiated potatoes were examined for their mutagenic activity in bacterial and mammalian cell systems. Negative results were obtained from all following test systems: Mutation assays with Salmonella typhimurium His - strains such as TA 100, TA 98, TA 1535, TA 1537, and streptomycin-dependent mutant (SM sup(d)) strain, TA 100 - 10, inductests with Escherichia coli strains, K 12 GY 5027 and K 12 C600, chromosomal aberration tests with Chinese hamster cells in culture, as well as micronucleus tests in mice. In addition, no difference in the mutagenic activities was found between extracts prepared from the irradiated and the unirradiated potatoes, suggesting that no mutagenic substance was produced in potatoes following gamma-irradiation. (author)

  18. Food irradiation

    Sato, Tomotaro; Aoki, Shohei

    1976-01-01

    Definition and significance of food irradiation were described. The details of its development and present state were also described. The effect of the irradiation on Irish potatoes, onions, wiener sausages, kamaboko (boiled fish-paste), and mandarin oranges was evaluated; and healthiness of food irradiation was discussed. Studies of the irradiation equipment for Irish potatoes in a large-sized container, and the silo-typed irradiation equipment for rice and wheat were mentioned. Shihoro RI center in Hokkaido which was put to practical use for the irradiation of Irish potatoes was introduced. The state of permission of food irradiation in foreign countries in 1975 was introduced. As a view of the food irradiation in the future, its utilization for the prevention of epidemics due to imported foods was mentioned. (Serizawa, K.)

  19. X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation

    Prasad, Mahendra

    1981-01-01

    In order to understand and solve numerous problems related to sugar quality and its storage life, X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation have been made. It is observed that the interplanar spacing 'd' in irradiated sucrose is reduced indicating the partial damage of sucrose lattice. (author)

  20. Preparation of Tritium from irradiated lithium compounds (study)

    1989-01-01

    The aim of the present study is the selection of a certain scheme for release, collection, measurement and analysis of Tritium as produced in Lithium compounds (Li[sub 2]O, LiOH, Li[sub 2]CO[sub 3] LiF and some Lithium alloys) in accordance with the [sup 6]Li(n, [alpha])T reaction. Tritium technology is of vital concern to power reactor programmes as well as to fusion technology. Meanwhile the fields of activity include, tritium generation and mangement in fission and fusion reactors; enviromental studies, release modeling HT/HTO conversion and dose assessments, absorption/ deabsorption, monitoring and plant design; research and development, labeling, compatibility and physical chemical properties.

  1. Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

    Shibuya, Tohru; Murora, Tetsuro; Iwahara, Shigeo; Hashimoto, Koroku; Minegishi, Atsuko.

    1982-01-01

    Alcohol extracts freshly prepared from gamma-irradiated and unirradiated potatoes were tested for the ability to induce dominant lethals in BDF 1 mice. Male mice were given 0.5 ml of extract twice a day, p.o., for 7 days and then mated with untreated female mice. Female mice were sacrificed on about the 13th day of pregnancy. No significant difference was observed in the number of living inplants between the group treated with extract prepared from unirradiated potatoes and that treated with the extract from 150 Gy (15 krad) irradiated potatoes. (author)

  2. Ion-irradiated polymer studied by a slow positron beam

    Kobayashi, Yoshinori; Kojima, Isao; Hishita, Shunichi; Suzuki, Takenori.

    1995-01-01

    Poly (aryl-ether-ether ketone) (PEEK) films were irradiated with 1MeV and 2MeV 0 + ions and the positron annihilation Doppler broadening was measured as a function of the positron energy. The annihilation lines recorded at relatively low positron energies were found to become broader with increasing the irradiation dose, suggesting that positronium (Ps) formation may be inhibited in the damaged regions. A correlation was observed between the Doppler broadening and spin densities determined by electron spin resonance (ESR). (author)

  3. An improved approach to identify irradiated dog feed by electron paramagnetic resonance study and thermoluminescence measurements

    Sanyal, Bhaskar, E-mail: bhaskar_sanyal@rediffmail.co [Food Technology Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India); Chawla, S.P.; Sharma, Arun [Food Technology Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    2011-05-15

    In the present study, probably for the first time, a detailed analysis of the radiation induced radical species and thermoluminescence measurements of irradiated dog feed are reported. The EPR spectrum of non-irradiated ready-to-eat dog feed was characterized by singlet g=2.0047{+-}0.0003. Irradiated samples exhibited a complex EPR spectrum. During high power (50.0 mW) EPR spectroscopy, a visible change in the shape of the EPR spectrum was observed and characterized by EPR spectrum simulation technique. An axially symmetric anisotropic signal with g{sub ||}=2.0028 and g{sub perpendicular}=1.9976 was identified. However, a negligible change in the matrix of irradiated edible dog chew was observed using EPR spectroscopy. Therefore, thermoluminescence study of the isolated minerals from dog chew was carried out. The composition of the poly-minerals was studied using SEM and EDX analysis and a complete verdict on identification of irradiation is proposed.

  4. An improved approach to identify irradiated dog feed by electron paramagnetic resonance study and thermoluminescence measurements

    Sanyal, Bhaskar; Chawla, S.P.; Sharma, Arun

    2011-01-01

    In the present study, probably for the first time, a detailed analysis of the radiation induced radical species and thermoluminescence measurements of irradiated dog feed are reported. The EPR spectrum of non-irradiated ready-to-eat dog feed was characterized by singlet g=2.0047±0.0003. Irradiated samples exhibited a complex EPR spectrum. During high power (50.0 mW) EPR spectroscopy, a visible change in the shape of the EPR spectrum was observed and characterized by EPR spectrum simulation technique. An axially symmetric anisotropic signal with g || =2.0028 and g perpendicular =1.9976 was identified. However, a negligible change in the matrix of irradiated edible dog chew was observed using EPR spectroscopy. Therefore, thermoluminescence study of the isolated minerals from dog chew was carried out. The composition of the poly-minerals was studied using SEM and EDX analysis and a complete verdict on identification of irradiation is proposed.

  5. Irradiation of Polystyrene and Polypropylene to study NIH 3T3 fibroblasts adhesion

    Arbeitman, C.R.; Grosso, M.F. del; Ibanez, I.; Garcia Bermudez, G.; Duran, H.; Chappa, V.C.; Mazzei, R.; Behar, M.

    2010-01-01

    When polymers are irradiated with heavy ions new chemical groups are created in a few microns of the material. The irradiation changed the polarity and wettability on the surface so that could enhance the biocompatibility of the modified polymer. The study of chemistry and nanoscale topography of the biomaterial is important in determining its potential applications in medicine and biotechnology, because their strong influence on cell function, adhesion and proliferation. In this study, thin films of Polystyrene and Polypropylene samples were modified by irradiation with low energy ion beams (30-150 keV) and swift heavy ions both with various fluences and energies. The changes were evaluated with different methods. Adhesion of NIH 3T3 fibroblasts onto unirradiated and irradiated surfaces has been studied by in vitro techniques. The correlations between physicochemical properties as a function of different irradiations parameters were compared with cell adhesion on the modified polymer surface.

  6. An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

    Scheuerlein, C; Hilleret, Noël; Taborelli, M; Brown, A; Baker, M A

    2002-01-01

    The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis resu...

  7. Uses of AES and RGA to study neutron-irradiation-enhanced segregation to internal surfaces

    Gessel, G.R.; White, C.L.

    1980-01-01

    The high flux of point defects to sinks during neutron irradiation can result in segregation of impurity or alloy additions to metals. Such segregants can be preexisting or produced by neutron-induced transmutations. This segregation is known to strongly influence swelling and mechanical properties. Over a period of years, facilities have been developed at ORNL incorporating AES and RGA to examine irradiated materials. Capabilities of this system include in situ tensile fracture at elevated temperatures under ultrahigh vacuum 10 -10 torr and helium release monitoring. AES and normal incidence inert ion sputtering are exploited to examine segregation at the fracture surface and chemical gradients near the surface

  8. Electron microscope study of irradiated beryllium oxide; Etude au microscope electronique de l'oxyde de beryllium irradie

    Bisson, A A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. {alpha}) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10{sup 19}, 9 x 10{sup 19} and 2 x 10{sup 20} n{sub f} cm{sup -2} at a temperature below 100 deg. C. For the irradiation at 6 x 10{sup 19} n{sub f} cm{sup -2}, the defects are merely visible, but at 2 x l0{sup 20} n{sub f} cm{sup -2} the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [French] L'oxyde de beryllium est d'abord etudie, par une methode fractographique, avant et apres irradiation, en

  9. In-situ TEM studies of microstructure evolution under ion irradiation for nuclear engineering applications

    Kaoumi, D.

    2011-01-01

    One of the difficulties of studying processes occurring under irradiation (in a reactor environment) is the lack of kinetics information since usually samples are examined ex situ (i.e. after irradiation) so that only snapshots of the process are available. Given the dynamic nature of the phenomena, direct in situ observation is invaluable for better understanding the mechanisms, kinetics and driving forces of the processes involved. This can be done using in situ ion irradiation in a TEM at the IVEM facility at Argonne National Laboratory which, in the USA, is a unique facility. To predict the in reactor behavior of alloys, it is essential to understand the basic mechanisms of radiation damage formation (loop density, defect interactions) and accumulation (loop evolution, precipitation or dissolution of second phases etc.). In-situ Ion-irradiation in a TEM has proven a very good tool for that purpose as it allows for the direct determination of the formation and evolution of irradiation-induced damage and the spatial correlation of the defect structures with the pre-existing microstructure (including lath boundaries, network dislocations and carbides) as a function of dose, dose rate, temperature and ion type. Using this technique, different aspects of microstructure evolution under irradiation were studied, such as defect cluster formation and evolution as a function of dose in advanced Ferritic/Martensitic (F/M) steels, the irradiation stability of precipitates in Oxide Dispersion Strengthened (ODS) steels, and irradiation-induced grain-growth. Such studies will be reported in this presentation

  10. Study of microstructural evolutions of the 6061-T6 aluminium alloy under irradiation

    Flament, Camille

    2015-01-01

    The 6061-T6 Aluminium alloy, whose microstructure contains Al(Fe,Mn,Cr)Si dispersoids and hardening needle-shaped β'' precipitates (Mg, Si), has been chosen as the structural material for the core vessel of the Material Testing Jules Horowitz Nuclear Reactor. Because it will be submitted to high neutron flux at a temperature around 50 C, it is necessary to study microstructural evolutions induced by irradiation and especially the stability of the second phase particles. In this work, an analytical study by in-situ and ex-situ electron and ion irradiations has been performed, as well as a study under neutron irradiation. The precipitate characterization by Transmission Electron Microscopy demonstrates that Al(Fe,Mn,Cr)Si dispersoids are driven under irradiation towards their equilibrium configuration, consisting of a core/shell structure, enhanced by irradiation, with a (Fe, Mn) enriched core surrounded by a Cr-enriched shell. In contrast, the (Mg,Si) β'' precipitates are destabilized by irradiation. They dissolve under ion irradiation in favor of a new precipitation of (Mg,Si,Cu,Cr,Al) rich clusters resulting in an increase of the alloy's hardness. β'' precipitates tend towards a transformation to cubic precipitates under neutron irradiation. (author) [fr

  11. Surface study of irradiated sapphires from Phrae Province, Thailand using AFM

    Monarumit, N.; Jivanantaka, P.; Mogmued, J.; Lhuaamporn, T.; Satitkune, S.

    2017-09-01

    The irradiation is one of the gemstone enhancements for improving the gem quality. Typically, there are many varieties of irradiated gemstones in the gem market such as diamond, topaz, and sapphire. However, it is hard to identify the gemstones before and after irradiation. The aim of this study is to analyze the surface morphology for classifying the pristine and irradiated sapphires using atomic force microscope (AFM). In this study, the sapphire samples were collected from Phrae Province, Thailand. The samples were irradiated by high energy electron beam for a dose of ionizing radiation at 40,000 kGy. As the results, the surface morphology of pristine sapphires shows regular atomic arrangement, whereas, the surface morphology of irradiated sapphires shows the nano-channel observed by the 2D and 3D AFM images. The atomic step height and root mean square roughness have changed after irradiation due to the micro-structural defect on the sapphire surface. Therefore, this study is a frontier application for sapphire identification before and after irradiation.

  12. Moessbauer study of defects in molybdenum and chromium irradiated with ions

    Troyan, V.A.; Bogdanov, V.V.; Ivanyushkin, E.M.; Pen'kov, Yu.P.

    1980-01-01

    Effects of ion irradiation of monocrystalline molybdenum and polycrystalline chromium with Co-57 impurity were studied by Moessbauer effect. Molybdenum specimens were irradiated by He + ions at accelerators with 40 keV energy. Chromium specimens were irradiated by hydrogen ions with 1.2 MeV energy up to integral 2x10 17 -2x10 19 ion/cm 2 doses. It is shown, that defect introduction into the source matrix by irradiation results in change of gamma-resonance line form and effect value. The observed effects of defect influence on spectrum parameters are discussed. It is concluded, that study of Moessbauer spectra parameters of diluted Co-57 solutions in matrices of different metals permits to determine dynamics of movement of impurity atoms and defects in metals irradiated with ions [ru

  13. Thermal studies on unirradiated and γ-irradiated polymer of allyl diglycol carbonate

    Kalsi, P.C.; Pandey, A.K.; Iyer, R.H.; Singh Mudher, K.D.

    1995-01-01

    The thermal decomposition of unirradiated and γ-irradiated (5.93-15.5 MRad dose range) allyl diglycol carbonate polymer (trade name, CR-39) was studied by thermogravimetry (TG) and differential thermal analysis (DTA). These studies indicate four main decomposition steps in CR-39 polymer in air. Assessment of the influence of radiation dose on the above range shows that while the 5.93 MRad γ-irradiated polymer CR-39 degrades in three steps, the 15.5 MRad γ-irradiated polymer degrades in only two steps. The kinetics of the different stages of degradation were also evaluated from the TG curves. Irradiation enhances the decomposition rate and the effect increases further with increasing radiation dose. The activation energy values calculated for all the decomposition stages decrease on irradiation

  14. Electron irradiated liquid encapsulated Czochralski grown undoped gallium antimonide studied by positron lifetime spectroscopy and photoluminescence

    Ma, S K; Lui, M K; Ling, C C; Fung, S; Beling, C D; Li, K F; Cheah, K W; Gong, M; Hang, H S; Weng, H M

    2004-01-01

    Electron irradiated undoped liquid encapsulated Czochralski (LEC) grown GaSb samples were studied by positron lifetime spectroscopy (PLS) and photoluminescence (PL). In addition to the 315 ps component reported in the previous studies, another defect with a lifetime of 280 ps was also identified in the present electron irradiated samples. The bulk lifetime of the GaSb material was found to be 258 ps. The V Ga,280ps and the V Ga,315ps defects were associated with two independent Ga vacancy related defects having different microstructures. The well known 777 meV PL signal (usually band A) was also observed in the electron irradiated undoped GaSb samples. The band A intensity decreases with increasing electron irradiation dosage and it disappears after the 300 deg. C annealing regardless of the irradiation dosage. The origin of the band A signal is also discussed

  15. Studies on the safety and consumer acceptance of gamma irradiated meats

    Kang, Il Jun [Hallym University, Kangwon (Korea); Lee, Cherl Ho [Korea University, Seoul (Korea); Kim, Jung Hee [Seoul Women' s University, Seoul (Korea)

    1999-04-01

    Gamma irradiation was applied to beefs (0-5 kGy) and porks (0-30 kGy) for evaluation of their possible genotoxicity, acute toxicity and four-week oral toxicity. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects of the irradiated samples tested were not shown in vivo mouse micronucleus assay. In an acute toxicity test, the maximal dose of 5,000 mg/kg did not change any toxic parameter examined in this study. In four-week oral toxicity study, no significant differences were found between the control and treatment groups. In the study of rat hepatocarcinogenesis, the consumption of gamma irradiated beef and pork not only does not affect the formation of lipid peroxide and membrane stability but also has a possibility to inhibit hepatocarcinogenesis. Also, the consumption of {gamma} - irradiated beef and pork does not affect antioxidative defense system. In the study of the biological safety of korean red pepper, no difference was found on microbial growth between pepper extract alone or irradiated pepper extract. In the preservation study of korean traditional rice-cake(garedok), irradiation dose below 10kGy had no influence on typical sensory characteristics. The shelf-life in rice-cakes with different conditions was the longest on 10kGy treatment than 5kGy. In investigation of the consumer attitude toward irradiated foods, the main reason for the concern about irradiated foods is that compounds in the products formed by irradiation. Therefore, regulatory authorities must be encouraged to permit the sale of irradiated items when wholesomeness is established. (author). 94 refs.,31 figs., 62 tabs.

  16. Studies on chronic effects of lower dose level irradiation

    Yun, T.G.; Yun, Y.S.; Yun, M.S.

    1980-01-01

    This experiment is being carried out to elucidate the chronic effects of Co 60 (γ-ray) - low doses irradiation on JCR mice at 3rd week, 6th week, and 5th month after their birth. Experimental mice at 3rd week of age have been irradiated with Co 60 - 60mR weekly, Co 60 - 500mR weekly and Co 60 - 61R biweekly at the dose rate of 60mR per second for 23 weeks until now. Co 60 - 61R irradiated mice were subdivided into Co 60 - alone group and Co 60 combined with red ginseng extracts group. In their survivor's rate and their body weight etc., no significant differences between control groups and test groups in these experimental mice. Experimented mice at 6 weeks and 5 months of age are also being irradiated with Co 60 in the same doses as the above for 14 weeks and 8 weeks until present. In these experimental groups, there are also no significant differences between control groups and experimental groups in their survivor's rate and their body weight

  17. Study on antibacterial activity of hydrogel from irradiated silk protein

    Bunnak, J.; Chaisupakitsin, M.

    2001-01-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N 2 atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  18. Studies on genetic variations in a sorghum variety irradiated with ...

    SORG 17) using gamma-ray irradiation from Cobolt 60 (Co60) source. The Mo seeds were grown in the off-season of 1985/86. This was bulk harvested and planted as M1 bulk in 1986. In 1986, ninety (90) M2 single seed selections were made as ...

  19. Experimental study on lyophilized irradiation sterilized nerve allografts in rabbits

    Yang Zhiyuan; Sun Shiquan; Liu Hechen

    1991-01-01

    Lyophilized irradiation sterilized nerve grafts in rabbits were used in allogeneic nerve transplantation. The result show that about 76% of experimental rabbits had fairly well morphologic (microscopic and electron microscopic) and electrophysiological recovery 3 month after operation. Preservation of neurilemmal tubes in nerve grafts, repopulation of Schwann cells in this tube and suppression of immune rejection are the key points in allogeneic nerve transplantation

  20. Study of effect of composition, irradiation and quenching on ionic ...

    The electrolyte samples are also quenched at liquid nitrogen temperature and conductivity measurements are carried out. The ionic conductivity at room temperature exhibits a characteristic peak for the composition, = 46. Electron beam irradiation results in an increase in conductivity for all compositions by a factor of 2–3.

  1. Microbeam evolution: From single cell irradiation to preclinical studies

    Ghita, Mihaela; Fernandez-Palomo, Cristian; Fukunaga, Hisanori

    2018-01-01

    Purpose: This review follows the development of microbeam technology from the early days of single cell irradiations, to investigations of specific cellular mechanisms and to the development of new treatment modalities in vivo. A number of microbeam applications are discussed with a focus on prec...... to deliver radiotherapy using plane parallel microbeams, in Microbeam Radiotherapy (MRT)....

  2. Positron Annihilation Study of Ion-irradiated Si

    Shin, Jung Ki; Kwon, Jun Hyun; Lee, Jong Yong

    2009-01-01

    Structural parts like a spaceship, satellite and solar cell are composed of metal alloy or semiconductor materials. Especially, Si is used as a primary candidate alloy. But, manned and robotic missions to the Earth's moon and Mars are exposed to a continuous flux of Galactic Cosmic Rays (GCR) and occasional, but intense, fluxes of Solar Energetic Particles. These natural radiations impose hazards to manned exploration. Irradiation of cosmic particle induces various changes in the mechanical and physical properties of device steels. It is, therefore, important to investigate radiation damage to the component materials in semiconductor. The evolution of radiation-induced defects leads to degradation of the mechanical properties. One of them includes irradiation embrittlement, which can cause a loss of ductility and further increase the probability of a brittle fracture. It can be more dangerous in the space. Positron annihilation lifetime spectroscopy(PALS) have been applied to investigate the production of vacancy-type defects for Ion-irradiated Si wafer penetrated by H, He, O and Fe ions. Then, we carried out a comparison with an un-irradiated Si wafer

  3. Study on antibacterial activity of hydrogel from irradiated silk protein

    Bunnak, J; Chaisupakitsin, M [King Mongkut' s Institute of Technology Lardkrabang, Bangkok (Thailand)

    2001-03-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N{sub 2} atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  4. A theoretical and experimental dose rate study at a multipurpose gamma irradiation facility in Ghana

    Sackey, Tracey A.

    2015-01-01

    Radiation dose rate monitoring out at the Radiation Technology Centre (RTC) of the Ghana Atomic Energy Commission (GAEC) to establish the safety or otherwise of staff at the occupied areas is presented. The facility operates a rectangular source of Co-60 gamma with an having activity of 27.4kCi as at March 2015 and has 14 workers. The aim of the research was determine by means of practical and theoretical evaluations shielding effectiveness of the irradiation chamber. This was to ensure that occupationally exposed workers are not over exposed or their exposures do not exceed the regulatory limits of 7.5μSv/h or 50mSv per annum. The study included dose rate measurements at controlled areas, evaluation of personnel dose history, comparison of experimental and theoretical values and determination of whether the shielding can support a. 18.5PBq (500kCi) Co-60 source. Practical dose rate measurements when the source was in the irradiation position was carried out using a Thermo Scientific Rad-Eye Gamma Survey Meter in the controlled areas of the facility which included the control room, electric room, deionizer room, on top of the roof of irradiation chamber (specifically above the roof plugs) and the two entrances to the irradiation chamber; the personnel door and the goods door. Background reading was found to be 0.08±0.01μSv/h whilst the average dose rates at the two entrances to the irradiation chamber (i e.,- the personnel door and the goods door) were measured to be 0.090μSv/h and 0.109μSv/h respectively. Practical measurements at the roof plugs produced average values of 0.135μSv/h. A particular point on the roof marked as plug-3 produced a relatively higher dose rate of 8.151μSv/h due probably to leakage along the cable to the drive motor. Measurements in the control room, electrical room and deionizer room had average readings of 0.116μSv/h, 0.089μSv/h and 0.614μSv/h respectively. All these average values were below the regulatory limits of 7.5

  5. Review of recent studies on neutron irradiation embrittlement in light water reactor pressure vessel steels

    Sudo, Akira; Miyazono, Shohachiro

    1983-06-01

    Recent studies in foreign countries (USA, France, FRG and UK) on neutron irradiation embrittlement have been reviewed. These studies are classified into four areas, such as 1) effect of chemical composition on irradiation embrittlement sensitivity, 2) postirradiation heat treatment for embrittlement relief, 3) fracture toughness evaluation of irradiated materials based on fracture mechanics analysis, and 4) effect of irradiation on fatigue crack propagation behavior. The first area mainly includes the studies related to the effects of copper, phosphorus impurities and nickel alloying and synergistic effect of these components, and furthermore, evaluation of Regulatory Guide 1.99 Rev.l. Studies in the second area show the effects of annealing condition (temperature and time) and metallugical condition on embrittlement relief, and evaluation of periodic annealing in the period of irradiation as a promising method for embrittlement control. Studies in the third area show the correlation between fracture toughness and Cv notch ductility changes with neutron irradiation, and J-R curves of irradiated materials based on the elasto-plastic fracture mechanics. In the forth area, most of studies are investigated in air condition but a few studies in reactor-grade water at high temperature and pressure. (author)

  6. Morphological studies on the healing process of extraction wound in irradiated rats

    Iizuka, Tadashi

    1984-01-01

    The present studies were performed to investigate the healing process of the extraction wound in irradiated rats and to clarify the effect of irradiation on bone formation and resorption. 282 Wistar rats of about 100g body weight were used. The region of the left upper molars of experimental rats was exposed to 1000 rad or 2000 rad of 60 Co. On the 7th day after irradiation, the left upper first molar of each rat was extracted. The rats were sacrificed at intervals of from 1 day to 28 days after extraction. Control rats were sacrificed at same intervals after extraction. The maxillary bone including the extraction wound was examined histologically, histometrically, histochemically and ultrastructurally. In irradiated rats, the healing process of extraction wound was disturbed. The osteoblastic new bone formation following production of granulation tissue and periosteal new bone formation was interfered. Histochemical examination revealed that the osteoblasts of irradiated rats reduced enzymatic activity compared with control rats. Ultrastructurally, the cytoplasmic organellae were poorly developed in the osteoblasts of irradiated rats and osteoid formation was reduced. In irradiated rats, the osteoclasts in the interradicular alveolar bone were more numerous and increased more rapidly as compared with control rats, whereas, histometrically, there was no significant difference in the amount of bone loss between control and irradiated rats. Histochemically, there was no distinct difference in the enzymatic activity in osteoclasts between control and irradiated rats. Ultrastructurally, the cytoplasmic organellae and ruffled border were poorly developed in the osteoclasts of irradiated rats. The findings suggest that irradiation induced cytological changes in not only oseoblasts but also osteoclasts and these changes resulted in the delayed healing of extraction wound. (author)

  7. Experimental study on irradiation injury of the kidneys, 2

    Tomita, Shinichi; Fuzikawa, Kiyozumi; Nishimori, Issei; Tsuda, Nobuo; Miyagawa, Naotaka

    1976-01-01

    In order to investigate irradiation injury of the kidney and effect of injured kidney on the whole body, especially cardiovascular changes, a single kidney was extracted from Wistar female rats and only the remained kidney was irradiated with a great amount of radiation in 4000 R dose experimentally. After seven weeks of irradiation, atrophy and involution of the highest region of the kidney were found. Histologically, fibrous proliferation of interstice accompanied with atrophy of the renal tubule, and slightly increased nuclei and lobulation of the glomerulus were recognized. After 15 weeks of irradiation, atrophy and involution of the whole kidney were found. Histologically, fibrous proliferation of interstice in the kidney accompanied with high degree atrophy of the renal tubule, marked increase and lobulation of mesangium ground substance of the glomerulus and mild hypertrophy of arteriole were recognized. Mild degeneration of myocardium was recognized. In the long-term cases passing 29 and 34 weeks after irradiation, blood pressure just before slaughter rose to 250 mmHg. The kidney showed malignant nephrosclerosis-like lesion, and panarteritis was found in the mesentery and peri-pancreatic artery. In the heart, hypertonic myocardosis was recognized. A rise of blood pressure which was observed in this experiment occurred in circulation degenerations resulted from the secondary hypertrophy of the blood vessels accompanied with fibrous proliferation of the interstice which appeared after degeneration of renal tubule. It was thought that panarteritis of cardiovascular system of the whole body, especially mesentery and peri-pancreatic artery, and fibrinoid degeneration of arteriole of the kidney were due to hypertension and angiopathic factors (non-vasopressor extracts from the injured kidney). (Tsunoda, M.)

  8. Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI) with Brewer measurements at El Arenosillo (Spain) - Part 2: Analysis of site aerosol influence

    Cachorro, V. E.; Toledano, C.; Antón, M.; Berjón, A.; de Frutos, A.; Vilaplana, J. M.; Arola, A.; Krotkov, N. A.

    2010-12-01

    Several validation studies have shown a notable overestimation of the clear sky ultraviolet (UV) irradiance at the Earth's surface derived from satellite sensors such as the Total Ozone Mapping Spectrometer (TOMS) and the Ozone Monitoring Instrument (OMI) with respect to ground-based UV data at many locations. Most of this positive bias is attributed to boundary layer aerosol absorption that is not accounted for in the TOMS/OMI operational UV algorithm. Therefore, the main objective of this study is to analyse the aerosol effect on the bias between OMI erythemal UV irradiance (UVER) and spectral UV (305 nm, 310 nm and 324 nm) surface irradiances and ground-based Brewer spectroradiometer measurements from October 2004 to December 2008 at El Arenosillo station (37.1° N, 6.7° W, 20 m a.s.l.), with meteorological conditions representative of the South-West of Spain. The effects of other factors as clouds, ozone and the solar elevation over this intercomparison were analysed in detail in a companion paper (Antón et al., 2010). In that paper the aerosol effects were studied making only a rough evaluation based on aerosol optical depth (AOD) information at 440 nm wavelength (visible range) without applying any correction. We have used the precise information given by single scattering albedo (SSA) from AERONET for the determination of absorbing aerosols which has allowed the correction of the OMI UV data. An aerosol correction expression was applied to the OMI operational UV data using two approaches to estimate the UV absorption aerosol optical depth, AAOD. The first approach was based on an assumption of constant SSA value of 0.91. This approach reduces the OMI UVER bias against the reference Brewer data from 13.4% to 8.4%. Second approach uses daily AERONET SSA values reducing the bias only to 11.6%. Therefore we have obtained a 37% and 12% of improvement respectively. For the spectral irradiance at 324 nm, the OMI bias is reduced from 10.5% to 6.98% for constant

  9. Study of irradiation damage by fast neutrons in samples of Portland cement

    Lucki, G.; Rosa Junior, A.A.

    1984-01-01

    The effect of neutron irradiation in samples of Portland cement was evaluated, using the resonance frequency method and pulse velocity of ultra-sound techniques. The samples were divided in three groups: 1) monitoring samples; 2) samples submitted to gamma heating; 3) Irradiated samples. In the sample preparation, it was used the Portland Santa Rita CP 320 cement, and water-cement rate of 0.40 l/Kg. The irradiation was done in the research reactor IEA-R1, at IPEN - CNEN/SP, with an integrated flux of 7.2 x 10 18 n/cm 2 (E approx. 1 MeV). Some damage were detected, due to the neutron flux, and by the thermal effect of gamma heating. (E.G.) [pt

  10. An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

    Scheuerlein, C; Taborelli, M; Brown, A; Baker, M A

    2002-01-01

    The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis results are compared with electron dose dependent secondary electron and electron stimulated desorption yield measurements. Initially the electron irradiation causes a surface cleaning through electron stimulated desorption, in particular of hydrogen. During this period both the electron stimulated desorption and secondary electron yield decrease as a function of electron dose. When the electron dose exceeds 10-4 C mm-2 electron stimulated desorption yields are reduced by several orders of magnitude and the electron beam indu...

  11. Study irradiation damage by fast neutrons in Portland cement by means of ultra-sound

    Rosa Junior, A.A.

    1988-01-01

    The effect of neutron irradiation in samples of Portland cement paste was evaluated, using the resonance frequency method and pulse velocity of ultra-sound technique. The samples were divide in three groups: 1) Monitoring samples; 2) Samples to gamma heating simulation; 3) Fast neutron irradiated samples in reactor core. Santa Rita Portland cement was utilized for samples preparation with water-cement rate of 0,40 l/kg. The irradiation was performed in the research reactor IEA-R1, at IPEN-CNEN/SP, with an integrated flux of 7,2 X 10 sup(18) n/cm sup(2) (E approx. 1 Mev). The samples of group 2 were submitted to special micro-waves heat treatment-with the same number of cycles of the reactor-which allowed the detection of fast neutron radiation effects within the predominant thermal effects. (author)

  12. An Experimental Study on the Change of Bone Mineral Metabolism After Irradiation

    Hong, Sung Woon; Lim, Sang Moo; Jang, Ja June; Lee, Jin Oh; Kang, Tae Woong

    1990-01-01

    Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The densitometry and bone scintigraphy are valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of Cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absorptiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before the presentation of the osteoradionecrosis can be diagnosed early with the dual photon absorptiometry and bone scintigraphy.

  13. A Study on Conjugate Heat Transfer Analysis of Reactor Vessel including Irradiated Structural Heat Source

    Yi, Kunwoo; Cho, Hyuksu; Im, Inyoung; Kim, Eunkee [KEPCO EnC, Daejeon (Korea, Republic of)

    2015-10-15

    Though Material reliability programs (MRPs) have a purpose to provide the evaluation or management methodologies for the operating RVI, the similar evaluation methodologies can be applied to the APR1400 fleet in the design stage for the evaluation of neutron irradiation effects. The purposes of this study are: to predict the thermal behavior whether or not irradiated structure heat source; to evaluate effective thermal conductivity (ETC) in relation to isotropic and anisotropic conductivity of porous media for APR1400 Reactor Vessel. The CFD simulations are performed so as to evaluate thermal behavior whether or not irradiated structure heat source and effective thermal conductivity for APR1400 Reactor Vessel. In respective of using irradiated structure heat source, the maximum temperature of fluid and core shroud for isotropic ETC are 325.8 .deg. C, 341.5 .deg. C. The total amount of irradiated structure heat source is about 5.41 MWth and not effect to fluid temperature.

  14. Conceptual design, neutronic and radioprotection study of a fast neutron irradiation station at SINQ

    Zanini, L.; Baluc, N.; Simone, A. De; Eichler, R.; Joray, S.; Manfrin, E.; Pouchon, M.; Rabaioli, S.; Schumann, D.; Welte, J.; Zhernosekov, K.

    2011-12-01

    This comprehensive, illustrated report by the Paul Scherrer Institute PSI in Switzerland documents the proposals concerning the conceptual design, neutronic and radioprotection study of a fast neutron irradiation station at the PSI's Swiss Spallation Neutron Source SINQ facility. The need for fast neutron irradiation is discussed and the possibility of using SINQ as a fast neutron irradiation facility is considered. The production of isotopes, tracers and medical isotopes is discussed, as are fission and fusion reactor technologies. The characteristics of the neutron spectrum in SINQ are discussed. The neutronic and radioprotection calculations for an irradiation station at SINQ are looked at in detail and extensive examples of work done and results obtained are presented and discussed. Radioprotection issues are also looked at. Further contributions in the report cover the hot/cold irradiation station in the SINQ target. An appendix provides detailed drawings of the facility's pneumatic delivery system

  15. A Study on the Thermal Neutron Filter for the Irradiation of Electronic Materials at HANARO

    Yang, Seong Woo; Kim, Sung Ryul; Park, Seung Jae; Shin, Yoon Taeg; Cho, Man Soon; Cho, Kee Nam [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The representative example is a technique of making the semiconductor with the transmutation using the pure Si. This NTD (Neutron Transmutation Doping) Si is used as a high-quality semiconductor because it has a uniform resistance. Likewise, the electronic materials are being investigated to improve the performance of material using the neutron irradiation method. The mechanism for reaction between the electronic materials and the neutrons depends on the energy of the neutron. Capturing reaction by thermal neutrons causes the transmutation and a lot of defects are made by fast neutrons. The study for the effect by such neutron energy is necessary to understand the performance improvement of the irradiated electronic materials. The thermal neutron filter was investigated to be used for the irradiation of electronic materials at HANARO. IP irradiation hole was selected and the irradiation device was designed. The analysis was conducted considering four candidate materials.

  16. Study on the physiological activities of gamma-irradiated seafood cooking drips

    Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Ju Yeoun [Chonbuk National University, Jeonju (Korea, Republic of)

    2010-03-15

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment.

  17. Preliminary study on mutagenic effects of heavy ions irradiation on maize inbred lines

    Yu Lixia; Li Wenjian; Xie Hongmei; Chen Xuejun; Chen Jing

    2010-01-01

    In order to study mutagenic effects of different heavy ions irradiation on maize inbred lines,corn seeds of Zheng58, Lu9801, Jinxiang4C-1, CSR24001, 308 and 478 were irradiated with 12 C 6+ and 36 Ar 18+ ions. The experimental results showed that the germination rate and planting percent were different after irradiation. The wettish seeds had higher sensibility to heavy ion irradiation. The leaf type of the plant appeared visible changes in M 1 generation. In M 2 generation, great changes had taken place in economic traits, many of which are beneficial mutation. Some beneficia1 mutation could be stably inherited in M 3 generation. From the above, it can be predicted that heavy ions irradiation is an effective means of genetic improvement of maize. (authors)

  18. Study on the physiological activities of gamma-irradiated seafood cooking drips

    Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon; Lee, Ju Yeoun

    2010-01-01

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment

  19. Suitability of Dukat strawberries for studying effects on shelf life of irradiation combined with cold storage

    Zegota, H.

    1988-01-01

    A new Dukat variety of strawberries was used to study the effect of irradiation combined with cold storage on their shelf life and chemical composition. Strawberries, with or without stems, were irradiated with a dose of 2.5 or 3.0 kGy within 6-10 or 20-24 h after harvesting. Results of the sensory evaluation showed that the minimum storage time for the fruits could be extended by a minimum of 9 days. If the time between harvest and irradiation was shorter, better results for storage experiments were obtained. Fruits with stems were more suitable for cold storage after irradiation than those without stems. Irradiation of strawberries did not change the titratable acidity and content of the reducing sugars. Colour intensity and ascorbic acid levels decreased in proportion to the absorbed dose and storage time. (orig.)

  20. Study of irradiated bone: Part III. /sup 99m/Tc pyrophosphate autoradiographic changes

    King, M.A.; Corriveau, O.; Casarett, G.W.; Weber, D.A.

    1978-01-01

    The macroautoradiographic and microautoradiographic localization of /sup 99m/Tc-pyrophosphate (/sup 99m/TcPPi) was studied in x-irradiated bone of rabbits up to one year post-irradiation. In cortical bone, /sup 99m/TcPPi was concentrated on bone surfaces near vasculature. Both forming and resorbing bone surfaces were comparably labeled at 2 hrs post-injection. Uptake on the surface of sites of haversian bone remodeling was observed to be at least part of the increased /sup 99m/TcPPi observed in irradiated bone in camera images. In irradiated trabecular bone 12 months following irradiation, a patchy decrease in /sup 99m/TcPPi uptake was correlated with localized decreases in vasculature

  1. A study on the proton irradiation effect of reactor materials using cyclotron

    Chi, Se Hwan; Park, Jong Man; Park, Deuk Keun; Lee, Bong Sang; Oh, Jong Myung

    1993-02-01

    Understanding on radiation damage of important structural materials is important for safe operation and radiation damage evaluation of new reactor structural materials. This study was performed to simulate and evaluate 14 MeV neutron irradiation effects on mechanical properties of candidate structural materials (HT-9/SS316) of next generation reactors (FBR, Fusion) irradiated by Cyclotron(MC-50) using SP test technique. After qualification of SP test techniques from J IC and ε qf correlation, SP tests were performed to evaluate 16MeV proton irradiation effects on mechanical properties of irradiated and unirradiated HT-9/SS316 steels. Test results were evaluated for ε qf , energy and displacement up to failure and J IC change. In addition, damaged zone and dpa upon depth after irradiation were calculated using TRIM code and Doppler broadening line shapes were measured to evaluate defects for 15% cold worked HT-9 steel using PAS. (Author)

  2. Preliminary study on the detection of irradiated food containing bone by ESR spectroscopy

    Zhao Yongfu; Ha Yiming; Liu Ting; Wang Rongfu; Wang Changbao

    2007-01-01

    Electron spin resonance (ESR) spectroscopy is one of the most effective technique for detection of irradiated food containing bone. It was found that the radiation -induced ESR signal (Spectrum, g factor and peak-to-peak line width AH) in bone before and after irradiation was significantly different and could be easily distinguished from the endogenous ESR signal. Sample preparation studies showed vacuum drying and grinding at frozen temperature was an ideal method. A linear relationship was observed between ESR signal intensity and the absorbed dose (0.3-10.1kGy). It can be proposed that 0.5kGy absorbed doses can be detected by ESR for irradiated food containing bone though detecting sensitivity is very different at the same irradiated dosage with different food such as pork, beef, duck, chicken and fish. The ultimate purpose of this work is to establish a national criterion for detection of irradiated foodstuffs by use of ESR. (authors)

  3. Fundamental Studies of Irradiation-Induced Modifications in Microstructural Evolution and Mechanical Properties of Advanced Alloys

    Stubbins, James; Heuser, Brent; Hosemann, Peter; Liu, Xiang

    2018-04-24

    This final technical report summarizes the research performed during October 2014 and December 2017, with a focus on investigating the radiation-induced microstructural and mechanical property modifications in optimized advanced alloys for sodium-cooled fast reactor (SFR) structural applications. To accomplish these objectives, the radiation responses of several different advanced alloys, including austenitic steel Alloy 709 (A709) and 316H, and ferritic/ martensitic Fe–9Cr steels T91 and G92, were investigated using a combination of microstructure characterizations and nanoindentation measurements. Different types of irradiation, including ex situ bulk ion irradiation and in situ transmission electron microscopy (TEM) ion irradiation, were employed in this study. Radiation-induced dislocations, precipitates, and voids were characterized by TEM. Scanning transmission electron microscopy with energy dispersive X-ray spectroscopy (STEM-EDS) and/or atom probe tomography (APT) were used to study radiation-induced segregation and precipitation. Nanoindentation was used for hardness measurements to study irradiation hardening. Austenitic A709 and 316H was bulk-irradiated by 3.5 MeV Fe++ ions to up to 150 peak dpa at 400, 500, and 600°. Compared to neutron-irradiated stainless steel (SS) 316, the Frank loop density of ion-irradiated A709 shows similar dose dependence at 400°, but very different temperature dependence. Due to the noticeable difference in the initial microstructure of A709 and 316H, no systematic comparison on the Frank loops in A709 vs 316H was made. It would be helpful that future ion irradiation study on 316 stainless steel could be conducted to directly compare the temperature dependence of Frank loop density in ion-irradiated 316 SS with that in neutron-irradiated 316 SS. In addition, future neutron irradiation on A709 at 400–600° at relative high dose (>10 dpa) can be carried out to compare with ion-irradiated A709. The radiation

  4. Study on shelf life extension of papayas irradiated by /sup 60/Co gamma-rays

    Chang, M.S.; Chen, M.D.; Lin, C.T.; Fu, Y.K.

    1984-11-01

    Papayas are one of the main fresh fruits in Taiwan area. Papaya fruits were treated with hot water to pasteurize peels followed by /sup 60/Co gamma-ray irradiation to extend the ripening time. The purpose of synergetic methods is to extend the shelf life of papaya fruits. This experiment was carried out by seven treatments, which were: (1) control group, (2) hot water treatment only, (3) hot water treatment with a 25 krad ..gamma..-irradiation, (4) hot water treatment with a 50 krad ..gamma..-irradiation, (5) hot water treatment with a 75 krad ..gamma..-irradiation, (6) 75 krad ..gamma..-irradiation only, and (7) hot water treatment with a 100 krad ..gamma..-irradiation. The items of observation were: surface yellowing, surface decaying, quality of texture, and length of period lasted after irradiation for 50% marketable papayas. The results of this study showed that a shelf-life extension of six days could be obtained for papayas subjected to hot water (50 to 55/sup 0/C) treatment and a 100 krad irradiation. 3 refs., 2 figs., 2 tabs.

  5. Analytic study of regional changes in carcinoma of the cervix uteri following linac irradiation, 3

    Yamashita, Michitaka

    1977-01-01

    To observe regional changes following Linac irradiation therapy for 15 patients with carcinoma of the cervix uteri, an electron microscopic study of the carcinomatous cells of a parabasal type was made, and the following conclusion was obtained. Early changes which were seen following 1000 R irradiation were an appearance of various lysosomes and a remarkable appearance of the Golgi's apparatus. Some other changes were noted in mitochondria, vesicles, and free ribosomes, while very slight changes in the nuclei. After 2000 R irradiation, the foregoing early changes and a tendency of cells separated became more distinctive. Following an irradiation of 3000 R, changes were noted in the nuclei, destruction of the nuclear membrane and agglutination of chromatin being prominent. Glycogen granules were also noted. After an irradiation of 4000-5000 R, the carcinomatous cells were necrotized and ill-defined. There were remarkable destructions of the nuclei and intracellular organellas. On the basis of the foregoing findings, it is considered that the effect of irradiation on the carcinomatous cells of a parabasal type in carcinoma of the cervix uteri appears as a change in the cytoplasm which is followed by the destructive change of the nuclei. A difference in the effect of irradiation was conspicuous in the changes of the lysosome. In remarkably effective cases, there occurred an early appearance and an early inactivation of the lysosome. However, in ineffective cases, those changes appeared after receiving 1000 R more irradiation. (Ueda, J.)

  6. Viability of platelets following storage in the irradiated state. A pair-controlled study

    Read, E.J.; Kodis, C.; Carter, C.S.; Leitman, S.F.

    1988-01-01

    Gamma irradiation of blood products is a standard practice recommended for the prevention of posttransfusion graft-versus-host disease in susceptible hosts. We studied the effects of irradiation on stored platelet concentrates and evaluated whether platelets could be stored for 5 days in the irradiated state without adverse effects on their viability. Using a pair-controlled design in which each of six normal subjects acted as his or her own control, we compared in vitro storage characteristics and in vivo kinetics of platelet concentrates exposed to 30 Gy and stored for 5 days with those of platelet concentrates simply stored for 5 days without irradiation. Irradiation had no significant effects on in vitro storage characteristics (platelet count, mean platelet volume, pH, and white cell count) or on in vivo kinetics, including initial recovery and mean platelet survival. Using the multiple-hit model, initial recovery was 49.6 +/- 10.8 percent, and mean platelet survival was 5.6 +/- 1.05 days for irradiated concentrates, compared with 51.3 +/- 13.0 percent and 5.9 +/- 0.50 days, respectively, for the unirradiated control concentrates. We conclude that irradiation of platelet concentrates with up to 30 Gy has no effect on their in vivo recovery or survival, and that irradiation administered before storage of platelet concentrates does not interfere with their clinical efficacy

  7. Electron beam irradiation: laboratory and field studies of cowpea seeds

    Srinivasan, K.; Chauhan, S.K.; Prasad, T.V.; Pramod, R.; Verma, V.P.; Petwal, V.; Dwivedi, J.; Bhalla, S.

    2015-01-01

    Cowpea (Vigna unguiculata) rich in protein and vitamins is emerging as one of the most important food legumes to tackle malnutrition. Pulse beetles (Callosobruchus chinensis and C. maculatus) are the pests of economic importance causing enormous losses during storage. Although various pest management strategies exist for the control of these pests, environmental concerns necessitate developing ecofriendly strategies. Electron beam (EB) irradiation has the potential to be a viable, non-chemical, residue-free strategy for management of pulse beetles during storage, but higher doses affect seed germination and viability. Hence, the present investigation was taken up to analyse the dosage effect of the irradiation on seed attributes of cowpea. Healthy cowpea seeds were irradiated with low energy electrons at different doses viz., 180, 360, 540, 720, 900, 1080, 1260, 1440 and 1620 Gy at 500 keV using the EB Accelerator facility at Raja Ramanna Centre for Advanced Technology, Indore. EB irradiated seeds were tested for physiological viz., germination, seedling vigour and vigour index and biochemical parameters viz., electrical conductivity of seed leachate, seed viability/tetrazolium test and dehydrogenase activity. Germination and vigour of the irradiated seeds were evaluated as per the ISTA Rules (ISTA, 1996). Vigour index was calculated as the product of germination percentage and seedling vigour. About 3,000 irradiated seeds from each dose were grown in the field at the Experimental farm, National Bureau of Plant Genetic Resources, New Delhi. Seeds harvested from 1500 individual plants of M 1 generation from each dose (50 seeds from each plant individually) were sown in next season and observed for chlorophyll mutations, if any. Results revealed that doses upto 1080 Gy (88%) did not affect the germination of cowpea seeds drastically as compared to untreated seeds (98%). Lower doses viz., 180 and 360 Gy had no impact on vigour components while higher doses (1080 Gy

  8. In vitro study of morphological and chemical modification threshold of bovine dental enamel irradiated by the holmium laser

    Eduardo, Patricia Lerro de Paula

    2001-01-01

    The aim of this study is to investigate the Ho:YLF laser effects on the dental enamel surface with regards to its morphology, thermal variations during its irradiation in the pulp chamber and its increased resistance to demineralization through quantitative analysis of calcium and phosphorous atoms reactive concentrations in samples. Twenty samples of bovine enamel were used and divided in four groups: control - acidulated phosphate fluoride (APF) application followed by demineralization treatment with lactic acid; irradiation with Ho:YLF laser (100 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid; irradiation with Ho:YLF laser (350 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid: and irradiation with Ho:YLF laser ( 450 J/cm 2 ) followed by APF topic application and demineralization treatment with lactic acid. Ali samples were quantified according to their calcium and phosphorous atoms relative concentrations before and after the treatments above. X-Ray fluorescence spectrochemical analysis and scanning electron microscopy were carried out. It was observed an increase on the calcium and phosphorous atoms concentration ratio and therefore the enamel demineralization reduction as a result of the lactic acid treatment in the samples irradiated with the holmium laser followed by the APF application. In order to evaluate the feasibility of this study for clinical purposes, morphological changes caused by the holmium laser irradiation were analyzed. Such modifications were characterized by melted and re-solidified regions of the enamel with consequent changes on its permeability and solubility. Temperature changes of ten human pre-molars teeth irradiated with 350 J/cm 2 and 450 J/cm 2 were also monitored in the pulp chamber in real time. Temperature increases over 4,20 C did not occur. The results obtained from this study along with the results from previous researches developed at

  9. Study on the effect of irradiation on algae by proteomics

    Choi, Jong Il; Yoon, Yo Han; Kim, Jae Hun

    2010-06-01

    Algae has been utilized as food material from long time ago, and recently newly recognized as functional materials and the source of bio-fuel. But, the study on the algae is just beginning and the study on protein expression and growth by the change of condition was not reported. In this study, the effect of radiation on the protein expression was investigated for the protection mechanisms and new genome source and furthermore, isolation of new mutant strains. To monitor the growth of algae, absorbance and FDA staining methods were developed and the content of lipid of algae species were measured. With these methods, the radiation sensitivity of algae species was determined. To investigate the proteome of algae, 2D-electrophoresis methods was applied. From the comparison of proteomes, the radiation specific expressed protein was identified as thioredoxin-h and its nucleotide sequences was defined. The expression of thioredoxin-h was further defined on the mRNA level. Also, the extract of algae species was analyzed for its antioxidant activity and polyphenolic content. The changes in antioxidant activity of extract by radiation was investigated. From the radiation experiments, mutant Spirogyra species having higher resistant against radical stress was obtained. The mutant strain has higher antioxidant activity. This results can provide the proteome date and mutation technology of algae and further contribute in the activation of fishery industry and national health enhancement

  10. In vivo genetic toxicity studies in Chinese hamsters fed irradiated or unirradiated foodstuffs

    Altmann, H.

    1982-01-01

    Two in vivo genetic toxicity studies were performed in Chinese hamsters fed irradiated or unirradiated diets of chicken, fish or dates in order to detect possible mutagenic effects caused by irradiating these foodstuffs. The tests selected for study were: 1. Chromosomal analysis of bone narrow cells and 2. DNA metabolism in spleen cells. Chicken, fish and dates were irradiated with doses of 7, 2.5 and 1 kGy respectively. These investigations were subsequently extended to include the effects of irradiated dried onions, pulses and cocoa beans on DNA metabolism in Chinese hamster spleen cells only. Dried onions were irradiated with doses of 0.15, 9 and 15 kGy, pulses with 10 kGy and cocoa beans with 3.2 to 5 kGy. In addition, a fumigated cocoa bean group was included. No significant differences in chromosomal aberration rate were detected between groups fed irradiated or unirradiated diets. Dried dates, whether irradiated or not, showed some evidence of genetic toxicity in their effect on DNA metabolism in the spleen cells of Chinese hamsters. Both date diets caused more strand breaks DNA than are usual for Chinese hamster spleen cells, but DNA repair was not adversely affected. Chicken, both irradiated and unirradiated, was found to enhance replicative DNA synthesis but had no effect on the DNA repair process. Irradiated fish, however, caused enhanced DNA synthesis compared to unirradiated fish, but also had no adverse effect on DNA repair. Irradiated white beans also enhanced DNA synthesis compared to controls whereas unirradiated samples inhibited synthesis. (orig./MG)

  11. Experimental studies on prevention of trichinosis by food irradiation (Co60)

    Shimazu, Kimitaka

    1993-01-01

    A systemic study was performed to elucidate the effects of 60 Co irradiation on maturation or fecundity of Trichinella spiralis by assessing from parasitological, morphological and immunological points of view. Pieces of muscle tissue of mice infected with T. spiralis were irradiated with 60 Co at doses of 50, 75, 100, 150 and 200 Gy. These irradiated tissue (Experimental group) and non-irradiated tissues (Control group) were fed to healthy mice. Half of the mice were sacrificed 6 days after the ingestion. The number of adult worms were counted and subjected to statistical analysis, which disclosed a good correlation between the dose of 60 Co irradiation and worm damage; the higher the dose the more damage parasites had, and no adults were recovered if the tissue had been irradiated with more than 150 Gy prior to infection. The same tendency was true for the histopathology of the intenstines of host mice; the higher the dose the less tissue damage. Circulating antigens of T. spiralis and antibodies against T. spiralis were detected in every serum examined by ELISA. The remaining mice were sacrificed 30 days after the ingestion. The numbers of muscle larvae were counted and subjected to statistical analysis, which disclosed a good correlation between th dose of 60 Co irradiation and worm damage, and no larvae were recovered if the tissue had been irradiated with more than 75Gy. Higher concentrations of circulating antigens of T. spiralis and antibodies against T. spiralis were detected in the serum samples taken with muscle larvae. Thus this study established that 60 Co irradiation of more than 150 Gy caused complete damage on maturation, and that irradiation of more than 75 Gy caused complete damage on the fecundity of T. spimalis. (author)

  12. Studies on safety and efficacy of gamma-irradiated ginseng

    Kwon, Joong Ho; Cho, Han Oak; Byun, Myung Woo; Kim, Suk Won; Yang, Jae Seung; You, Young Soo; Jin, Joon Ha; Park, Soon Chul

    1992-09-01

    Microbiological qualities were evaluated for the commercial red ginseng. Molds, which might cause microbial spoilage of stored ginseng, were isolated and identified for determining radiosensitivity and growth characteristics on ginseng-extract agar media. Red ginseng inoculated with isolated molds was incubated under the ideal condition following irradiation at different doses to pre-establish the effective dose-range for decontamination by confirming mold growth on the surface of the sample. At this point of time, moisture content was determined for the corresponding sample. By comparing the monolayer moisture content of red ginseng and its actual moisture level causing microbial spoilage during storage, it was intended to establish a basal condition for the continued project regarding irradiation effects on the quality of high-moisture products and their storage stability. (Author)

  13. Gamma irradiation studies on Gladiolus cv. White Friendship

    Banerji, B.K.; Datta, S.K.; Sharma, S.C.

    1994-01-01

    Dormant corms of Gladiolus cv. White Friendship were irradiated with 250, 500, 750, 1000 and 1250 Gy of gamma rays. Reduction in survival, plant height, number of leaves and floret, spike length, leaf and corm size and delayed flowering were recorded after irradiation. Morphological abnormalities in foliage and florets and chromosomal aberration during root tip mitosis increased with increase in exposure. Flowering was ceased cent per cent in highest dose of 1250 Gy. LD 50 on survival basis was found in 750 Gy exposure. MV 2 and MV 3 also followed the similar pattern of results as exhibited by MV 1 plants. Pink flower colour mutation was detected in few plants as sectorial chimeric form in MV 2 in treated population. In MV 3 one plant produced spike with lighter pink florets in 750 Gy treatment. This mutant has been isolated in pure form. (author). 10 refs., 2 figs., 2 tabs

  14. Study about internal friction in deformed - and irradiated pure titanium

    Miyada, L.T.

    1979-01-01

    Internal friction and modulus are measured in pure Ti at low temperature using an inverted torsion-pendulum at about 1 Hz. The presence of four relaxation peaks P' sub(d)(-140 0 C), P sub(d)(-101 0 C), P' sub(α)(-75 0 C) and P sub(α)(-50 0 C) has been found, and effects of plastic deformation, heat treatment and neutron irradiation on these peaks are investigated in detail. Activation energies and frequency factors of P sub(d) and Pα peaks are consistent with the data in higher frequency range reproted by other workers. The P sub(d) and P' sub(d) peaks grow after deformation and tend to decay after annealing at high temperatures or after neutron irradiation. Both peaks are resonably interpreted in terms of dislocation relaxation mechanisms (Bordoni type) arising from thermally activated motion of dislocations in different slip planes of h.c.f. structure. Peierls stress of dislocations giving rise to each peak have calculated based on Seeger's theory, and found to be consistent with that of f.c.c. metals. On the other hand, P sub(α) and P' sub(α) peaks grow significantly at the expense of P sub(d) and P' sub(d) peaks after neutron irradiation in deformed samples. The behaviour of these peaks as a function of irradiation dose and annealing temperatures strongly indicated that they are due to relaxations resulting from dislocations-point defects interactions (Hasiguti type). It is tentatively suggested that P sub(α) and P' sub(α) peaks are related with interactions of dislocations with divacancies and single vacancies, respectively. Application of Schiller's model showed a consistent result with regard to the P' sub(α) peak experimentally observed. (Author) [pt

  15. 3D detectors at ITC-irst: first irradiation studies

    Ronchin, S.; Boscardin, M.; Bosisio, L.; Cindro, V.; Dalla Betta, G.-F.; Piemonte, C.; Pozza, A.; Zoboli, A.; Zorzi, N.

    2007-01-01

    In the past two years, we have developed 3D detector technologies at ITC-irst (Trento, Italy). We have proposed a new 3D architecture, having columnar electrodes of one doping type only, allowing for a simplified fabrication process. In this paper, we report on preliminary results from the electrical characterization of devices irradiated with neutrons, showing that low depletion voltage values can be achieved even after very large fluences

  16. Miniature tensile test specimens for fusion reactor irradiation studies

    Klueh, R.L.

    1985-01-01

    Three miniature sheet-type tensile specimens and a miniature rod-type specimen are being used to determine irradiated tensile properties for alloy development for fusion reactors. The tensile properties of type 316 stainless steel were determined with these different specimens, and the results were compared. Reasonably good agreement was observed. However, there were differences that led to recommendations on which specimens are preferred. 4 references, 9 figures, 6 tables

  17. Study of damaged depth profiles of ion-irradiated PEEK

    Vacík, Jiří; Hnatowicz, Vladimír; Červená, Jarmila; Apel, P. Yu.; Posta, S.; Kobayashi, Y.

    2007-01-01

    Roč. 201, 19-20 (2007), s. 8370-8372 ISSN 0257-8972 R&D Projects: GA MPO(CZ) 1H-PK2/05; GA MŠk 1P04LA213 Institutional research plan: CEZ:AV0Z10480505 Keywords : Oxygen irradiation * Poly-aryl-ether-ether ketone * Thermal neutron depth profiling (TNDP) Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.678, year: 2007

  18. ESR (Electronic Spin Resonance Spectroscopy) study of irradiated paper for biomedical material wrapping

    Huarte, Monica; Rubin de Celis, Emilio; Kairiyama, Eulogia; Zapata, Miguel; Santoro, Natalia; Magnavacca, Cecilia

    2009-01-01

    Ionising radiation treatments are used for sterilization, microbiological decontamination, disinfection, insect disinfestation and food preservation. This ionising radiation generates free radicals (FR) in matter, which can be detected by Electronic Spin Resonance Spectroscopy (ESR). For this work it had analysed different kind of irradiated package papers of syringes, surgical gloves and dressings by ESR. These were irradiated with doses between 20 and 35 kGy of gamma radiation (Cobalt 60). The processed samples were measured in a Bruker ECS 106 spectrometer. The obtained results were: 1-) The irritated samples showed a central peak and two satellites induced by the applied radiation; 2-) The non-irradiated samples did not show the characteristic satellite peaks of the irritated ones; 3-) A linear relationship between the signal heights per unit mass and the applied doses was found; and 4-) The signals were highly stable, with half-time values between 240 and 370 days for 20 and 30 kGy, permitting more than one year of monitoring proceedings. In conclusion, the ESR allows the detection, quantification and time monitoring processes of this kind of irradiated materials. (author) [es

  19. Response comparative study of Rn-222 alpha particles track monitors

    Pereira, Osvaldo Luiz dos Santos

    2010-01-01

    This work was a comparative study between the responses of three monitors, the NRPB, an acrylic monitor (in thin film geometry) and the aluminum monitor (also thin film geometry) in controlled and mixed environment. The experiments consisted on placing the monitors in a plastic tube, with a radio-226 source internal. Only internal CR-39 plastic detectors were analyzed in this work. It was found that the monitors in thin film geometry had activities response of approximately 15% less than the NRPB monitors. All monitors responded the same way when in controlled environment. Related to the type of material, conductive plastic or dielectric (insulator) plastic, the NRPB, in environments without ventilation, responded in the same way. (author)

  20. Studies on irradiated lactate dehydrogenase using gel electrophoresis

    Huth, O.

    1981-01-01

    LDH in aqueous phosphate buffer solution was x-irradiated under nitrogen and dinitrogen oxide. The pre-treated samples were separated by SDS-phosphate gel electrophoresis. Colour yields of the protein bands were determined by planimetry following staining and photometric densitometry. It could be shown that aggregates formed up to the tetramer size were mainly covalently bonded and that negligent amounts of fragments are formed. No exact statements could be made concerning products formed after longer irradiation treatment. Measurements under UV-light also revealed an elevated base from the point of application to the band at the native LDH level; this supports the theory of a reduced migration path through intra-molecular bonding. No firm conclusions can be drawn from the process of staining because CBB itself leads to an increased background colouring between closely-lying protein bands. It could be shown that OH-radicals cause greater changes than H-radicals or solvated electrons since the native LDH peak diminished fastest when irradiated under dinitrogen oxide. With regard to radiation effect it could be demonstrated that a higher radiation dose was required for degradation of the LDH molecule than for its inactivation. These values approach each other with increasing concentration. This indicates that at low concentrations inactivation of the enzyme is mainly caused by conformational changes and at high concentrations by aggregation. Disulphide bridges were found to contribute to aggregate formation in 5-15% of the aggregates formed, this increasing linearly with concentration. (orig./MG) [de

  1. Study on irradiated polymerization of acrylonitrile by NMR

    Zhao Xin; Lin Hao

    1999-01-01

    Sup 13 C CP/MAS spectra and nuclear Overhauser effects (NOE) at room temperature have been measured for acrylonitrile (AN) in homophase irradiated polymerization. With the increase of radiation dose the chemical shift of cracking peaks and NOE are variation. This implies that the polymerized mechanism of AN were changed with the variation of irradiated doses and dose rate. There is the stronger affinity electron group (-CN) in acrylonitrile monomer. It may be polymerized by various ways and mechanism and be gained the polymer of difference structures and molecular weight of polyacrylonitrile (PAN). Starmicarbon and Starker obtained higher molecular weight of polyacrylonitrile by peroxysulfate-pyrosulfite in oxidation-reduction system. The superhigh molecular weight of PAN was synthesized chemically according to the method of Wu et. al. by suspension polymerization. In this paper we discussed that the relative concentrations of steric dyads and triads in the chain structure in PAN and the irradiation polymerized mechanism of acrylonitrile monomer in room temperature by different dose and dose rate

  2. Irradiation effect study on dynamic performance of grease

    Arakawa, Kazuo; Sasuga, Tsuneo; Hagiwara, Miyuki; Yajima, Toshio; Nakanishi, Hiroshi; Soda, Takao; Iwamoto, Takeshi.

    1986-03-01

    The radiation resistance of newly developed grease, MORESCO HIRAD RG-42-0, consisting of polyphenyl ether as base oil and inorganic compound as gelling agent was evaluated by conducting measurements of frictional resistance force on mechanical snubbers. After the irradiation of 60 Co γ-rays up to a predetermined dose [max. 100 MGy (10000 Mrad)], the grease was applied to mechanical snubbers. The rated load of mechanical snubbers used (standard stroke of 125 mm) was set at 0.16 ton and 1.0 ton. The frictional resistance force was measured at a velocity of 0.001, 0.01, 0.1 and 2.0 mm/sec and at temperature of 60 deg C. When the rated load was 0.16 ton, the frictional resistance force of irradiated grease was kept less than a criterion, a greater value of either 5 kgf or 1 % of the rated load, at every tested dose up to 90 MGy. In case of 1.0 ton, the frictional resistance force of the irradiated grease was less than a greater value of either 10 kgf or 1 % of the rated load at doses up to 70 MGy. (author)

  3. Economic Feasibility Study about the Possibility of Setting Food Irradiation Technology Locally in the Arab Countries

    El Gameel, E.A.

    2011-01-01

    The previous economic studies on the food irradiation focused on the financial and marketing according to the private investigator's point of view. In this study the food irradiation technology evaluated according to the society's point of view since it is risky to focus on the technical, financial sides only. This study has evaluated the expected benefits on the national income, the employment, the payment balance and the dependence on the foreign countries.

  4. High-temperature annealing of proton irradiated beryllium – A dilatometry-based study

    Simos, Nikolaos, E-mail: simos@bnl.gov [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Savkliyildiz, Ilyas [Rutgers University (United States)

    2016-08-15

    S−200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 10{sup 20} cm{sup −2} peak fluence and irradiation temperatures in the range of 100–200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation {sup 4}He and {sup 3}H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  5. Studies of soy sauce sterilization and its special flavour improvement by gamma-ray irradiation

    Yang Jingtian; Jin Xinhua; Gu Guoxing; Yun Guichun

    1988-01-01

    Experimental studies for sterilizing 12 kinds of soy sauce with gamma-ray irradiation showed that both sterilization and improvements in flavour and quality of soy sauce were obtained simultaneously. (author)

  6. Studies on mutagenic activity of 60Co γ-ray irradiated rape pollen

    He Weishun; Liu Aihua; Lin Shiying; Xiong Xikun

    1989-01-01

    In the present study on disinfection, the rape pollen was irradiated with 2.5 kGy 60 Co γ-ray. Micronuclei, sister chromatid exchanges (SCE) of bone marrow cells and chromosomal aberrations of meiotic cells in mice were used as an indicater of chromosomal damage to study the mutagenicity of irradiated rape pollen. The results are as follows: (1) The frequency of micronuclei in polychromatic erythrocytes is 2.00 per mille; nucleated cells is 0.8 per mille in control group. In the numbers of polychromatic erythrocytes and nucleated cells with micronuclei, there is no obviously difference in irradiated and unirradiated groups. (2) SCE incidence of control group is 2.01 ± 0.12/cell. No significant difference in the frequency of SCE exists between non-irradiated rape pollen and the control groups. But the frequency of SCE in irradiated rape pollen group (3000 mg/kg/day x 7) is 2.36 ± 0.12/cell; high dose group (6000 mg/kg/day x 7) is 2.96 ± 0.14/cell. In comparison with control group, there is a significant difference. (3) The chromatid breaks, fragments, and univalents in primary spermatocytes have been obseved. The frequencies of chromosomal aberration showed no obviously difference among irradiated and non-irradiated rape pollen groups

  7. Molecular dynamics study on interfacial thermal conductance of unirradiated and irradiated SiC/C

    Wang, Qingyu; Wang, Chenglong; Zhang, Yue; Li, Taosheng

    2014-01-01

    SiC f /SiC composite materials have been considered as candidate structural materials for several types of advanced nuclear reactors. Both experimental and computer simulations studies have revealed the degradation of thermal conductivity for this material after irradiation. The objective of this study is to investigate the effect of SiC/graphite interface structure and irradiation on the interfacial thermal conductance by using molecular dynamics simulation. Five SiC/graphite composite models were created with different interface structures, and irradiation was introduced near the interfaces. Thermal conductance was calculated by means of reverse-NEMD method. Results show that there is a positive correlation between the interfacial energy and interfacial C–Si bond quantity, and irradiated models showed higher interfacial energy compared with their unirradiated counterparts. Except the model with graphite atom plane parallel to the interface, the interfacial thermal conductance of unirradiated and irradiated (1000 eV) models, increases as the increase of interfacial energy, respectively. For all irradiated models, lattice defects are of importance in impacting the interfacial thermal conductance depending on the interface structure. For the model with graphite layer parallel to the interface, the interfacial thermal conductance increased after irradiation, for the other models the interfacial thermal conductance decreased. The vibrational density of states of atoms in the interfacial region was calculated to analyze the phonon mismatch at the interface

  8. Histopathological studies on the effects of preoperative irradiation for cancer of the esophagus

    Goseki, Narihide

    1979-01-01

    Though a criterion for histopathological changes by radiotherapy was determined by the study group of esophageal diseases, this criterion is not always compatible with clinical findings and prognosis of each patient. To review this point again, degenerative changes in esophageal cancer cells due to irradiation and the distribution of cancer cells in the esophageal wall were observed. To evaluate the Ef classification of esophageal cancer, histopathological studies of resected en bloc specimens from 36 patients with advanced esophageal cancer who had received preoperative irradiation were performed. Cancer cells with slight degeneration distributed around the cancer lesions in 29 cases (81%). This result indicates that it is not accurate to evaluate the effect of radiation histopathologically, based upon the Ef classification, unless the en bloc segmented specimens are prepared. Histopathological evaluation of effects of irradiation indicated that effective rate of irradiation were significantly higher when total dose of over 4,000 rad was irradiated and the intervals between irradiation and surgery were within 20 days. In 16 of 20 patients in whom cancer cells with slight degeneration (d 1 ) were observed, cancer cells with degenerative changes of d 1 grade still remained in the adventitia, and expected improvement of a-factor by irradiation was observed in less cases than previously reported. (Tsunoda, M.)

  9. 75 MeV boron ion irradiation studies on Si PIN photodiodes

    Prabhakara Rao, Y.P.; Praveen, K.C. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Rejeena Rani, Y. [Integrated Circuits Division, Bharat Electronics Limited, Bangalore 560013, Karnataka (India); Tripathi, Ambuj [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Gnana Prakash, A.P., E-mail: gnanap@hotmail.com [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India)

    2013-12-01

    The highly sensitive silicon PIN photodiodes were fabricated to use in radiation environments. The Si PIN photodiodes are coated with 150 nm silicon dioxide (SiO{sub 2}) as anti-reflective (AR) coating. The presence of AR coating on the performance of irradiated PIN photodiodes is studied up to a total dose of 10 Mrad. The effects of 75 MeV boron (B{sup 5+}) ions and {sup 60}Co gamma radiation on the I–V, C–V and spectral responses of PIN photodiodes were studied systematically to understand the radiation tolerance of the devices. The 75 MeV B{sup 5+} irradiation results are compared with {sup 60}Co gamma irradiated results in the same dose range for 1 mm × 1 mm and 10 mm × 10 mm active area PIN photodiodes. The irradiation results show that the ion irradiated PIN photodiodes show more degradation when compared {sup 60}Co gamma irradiated devices. The irradiation results are presented in this paper and the possible mechanism behind the degradation of photodiodes is also discussed in the paper.

  10. Optimizing study design for multi-species avian monitoring programmes

    Jamie S. Sanderlin; William M. Block; Joseph L. Ganey

    2014-01-01

    Many monitoring programmes are successful at monitoring common species, whereas rare species, which are often of highest conservation concern, may be detected infrequently. Study designs that increase the probability of detecting rare species at least once over the study period, while collecting adequate data on common species, strengthen programme ability to address...

  11. Study on city underground NBC monitoring technology

    Hu Jiewei; Fang Zongliang; Wen Qilin; Cao Jianfeng; Peng Jing; Xu Feiyan

    2012-01-01

    Recent years, the NBC terrorism threat has become the major terrorist form which affects the national security and the public lives and properties. As the great power of politics and economy, and the main power of anti-terrorism around the world, China also faces the critical challenge of guarding against the NBC terrorist attack. The subway has become the main transportation due to its inexpensiveness and convenience, which also makes subway the target of terrorism attack. The paper discusses how to set up an NBC integrated monitoring technique suitable for city subways, and proposes a relative solution. (authors)

  12. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    Yu, H.; Yao, Z.; Kirk, M.A.; Daymond, M.R.

    2015-01-01

    In situ heavy ion irradiation with 1 MeV Kr"2"+ was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 "oC or 450 "oC. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 "oC irradiation but not at 450 "oC. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2 and both present in β-Zr under room temperature irradiation. (author)

  13. Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

    Yu, H.; Yao, Z., E-mail: 12hy1@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada); Kirk, M.A. [Argonne National Laboratory, Materials Science Division, Argonne, IL (United States); Daymond, M.R. [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

    2015-07-01

    In situ heavy ion irradiation with 1 MeV Kr{sup 2+} was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 {sup o}C or 450 {sup o}C. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 {sup o}C irradiation but not at 450 {sup o}C. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2<111> and <001> both present in β-Zr under room temperature irradiation. (author)

  14. Wholesomeness studies of irradiated salted and dried mackerel, using rats. Part of a coordinated programme on the wholesomeness of the process of food irradiation

    Anukarahanonta, T.

    1978-04-01

    Chronic toxicity of irradiated salted and dried mackerel was evaluated by multi-generation rat feeding studies. Salted and dried mackerel samples were irradiated with 200krad, ground and mixed with a standard laboratory animal diet at 28% w/w. Wistar strain rats were used in the experiment and were divided into 3 groups and fed their respective diets, i.e. stock ration, diet containing 28% of non-irradiated salted and dried mackerel and diet containing 28% of irradiated salted and dried mackerel. The test was carried out for 3 generations. The results revealed no significant difference that would impose a hazard attributable to consumption of irradiated salted and dried mackerel with respect to longevity, carcinogenicity, teratogenicity, dominant lethal, reproductive function and biophysiological function in animals tested

  15. Studies on the effect of gamma irradiation on shelf life of Kagzi lime (Citrus aurantifolia swingle)

    Pandey, S.K.; Bisen, A.

    2006-01-01

    Influence of irradiation on shelf life of Kagzi lime fruits were studied. The results revealed that most of the physical and chemical parameters of fruits were significantly influenced by 100 Gy gamma radiation up to 22 days without affecting fruit quality. Higher doses of gamma irradiation (> 200 Gy) deteriorated the fruit quality and organoleptic parameters of the fruit. Thus, irradiation of lime fruits with 100 Gy gamma radiation extended shelf life of lime fruits and also helps in maintaining the chemical constituents viz., T.S.S. Acidity, Vitamin C, pH and juice content. (author)

  16. Alveolar wound healing after x-irradiation: a histologic, radiographic, and histometric study

    Guglielmotti, M.B.; Ubios, A.M.; Cabrini, R.L.

    1986-01-01

    Healing of extraction wounds in rats following cephalic irradiation was studied by histologic, radiographic, and histometric methods 14 days after tooth extraction. Irradiation was given at 0, 3, and 7 days after surgery in doses of either 15, 20, or 30 Gy. No significant differences were seen with the different doses given seven days post-extraction. However, socket healing was delayed when irradiation was given immediately and three days after extraction. On the basis of these observations, it is recommended that radiation not begin until at least one week after the extraction of teeth

  17. Studies of Sterile Irradiation Effects on the White-striped Fruit Fly

    Limohpasmanee, Wanitch; Tannarin, Thodsapol; Khongratarpon, Titima; Segsarnviriya, Suchada

    2011-06-01

    Full text: In general, sterile irradiation can affect vigor and mating competitiveness of the fruit flies. The objective of the experiments was to study the effects of sterile irradiation on the white-striped oriental fruit fly, Bactrocera dorsalis (Hendel), developed for sterile fly detection. A day before adult emergence, the pupae were irradiated at the dose of 90 Grays. No effects on adult emergence and flight ability were observed. However, it induced complete sterility in both sexes. Also, it decreased male mating competitiveness significantly, while increasing sexual competitiveness significantly

  18. Economic feasibility study of onion and potato irradiation in the Syrian Arab Republic

    Al-Bachir, M.; El-Den-Sharabi, N.; Midani, M.Ayman

    1995-01-01

    The purpose of this study was to examine the economic and financial feasibility of a food irradiation project proposed by the Syrian Atomic Energy Commission. The prime purpose of the project was to irradiate two important agricultural products, namely, onion and potato. The irradiation process has the effect of reducing sprouting significantly. In Syria onions are usually stored in well ventilated warehouses at ambient temperature. Our investigation showed that sprouting started after 1.5 months of storage. It is estimated that the sprouting rate reaches 100% after five months of storage. This implies a waste factor of 50%. (author). 7 refs., 4 tabs

  19. Study on preservation of sweet apricot kernel (SAK) by γ-irradiation

    Wang Jide; Xu Fang

    1992-01-01

    This paper introduces the study on effect of insecticide and sterilization of SAK by 60 Co γ irradiation. The results declare that the proper dose kill the insect eggs on the surface of SAK is 3.5 kGy, the preserving period under ambient temperature is up to 7 months, the intactness rate is 100%, and the SAK can be safely stored through the summer. By the irradiation of 3.5 kGy, the sanitary quality of SAK can be notably improved and the amount of microbes can decrease by at least 99%. There are no remarkable changes of the main nutrition components of irradiated SAK

  20. A study on the irradiation effect of reactor materials using a cyclotron

    Hong, Joon Hwa; Ji, Se Hwan; Kang, Yung Hwan; Park, Duk Keun; Park, Jong Man; Lee, Bong Sang; Oh, Jong Myung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    The objectives of the present study are to develop the simulation techniques of neutron irradiation through ion irradiation using a Cyclotron and small specimen techniques and to evaluate radiation effects of reactor materials. Effects of proton or neutron irradiation on domestic 12Cr-1MoV and SA508-3 steels were evaluated by small scale specimen test techniques, i.e, small punch and miniaturized tensile test. In order to study the radiation damage mechanism, irradiation effects of the steels were investigated by means of property change tests such as microstructure, physical and thermal properties. Feasibility study on application of a magnetic non-destructive methods to evaluate radiation effects on RPV materials was performed. 109 figs, 12 tabs, 102 refs. (Author).

  1. A study on the irradiation effect of reactor materials using a cyclotron

    Hong, Joon Hwa; Ji, Se Hwan; Kang, Yung Hwan; Park, Duk Keun; Park, Jong Man; Lee, Bong Sang; Oh, Jong Myung

    1994-12-01

    The objectives of the present study are to develop the simulation techniques of neutron irradiation through ion irradiation using a Cyclotron and small specimen techniques and to evaluate radiation effects of reactor materials. Effects of proton or neutron irradiation on domestic 12Cr-1MoV and SA508-3 steels were evaluated by small scale specimen test techniques, i.e, small punch and miniaturized tensile test. In order to study the radiation damage mechanism, irradiation effects of the steels were investigated by means of property change tests such as microstructure, physical and thermal properties. Feasibility study on application of a magnetic non-destructive methods to evaluate radiation effects on RPV materials was performed. 109 figs, 12 tabs, 102 refs. (Author)

  2. Monitor of spatial plans. Feasibility study

    Bollen, M.J.S.; Ritsema van Eck, J.; Farjon, J.M.J.

    2008-01-01

    The national government needs assessments of consequences of building projects in relation to spatial policy objectives such as the prevention of urban sprawl or the development of landscape qualities. Normally the effects of spatial policies appear after several years. Spatial plans can possibly indicate these effects earlier. To allow policies to be adapted to unwanted developments, the assessments should be available in the early planning stages of these building projects. The Dutch Minister of VROM has asked the Netherlands Environmental Assessment Agency to investigate the feasibility of a monitoring system based on building plans. As building projects take a long period from conception until realization, a monitoring system for these projects should include all plans for the next ten to fifteen years with an indication of the chance that these plans are realized. The existing databases in the Netherlands provide sufficient information to assess consequences of plans for those objectives that are directly related to the urbanization pattern. However, an improvement of these databases is necessary, amongst other things by coordination of these databases [nl

  3. A Study on Structural Strength of Irradiated Spacer Grid for PWR Fuel

    Jin, Y. G.; Baek, S. J.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Chun, Y. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, J. I.; Kim, Y. H.; Lee, J. J. [KEPCO NF, Daejeon (Korea, Republic of)

    2014-10-15

    A fuel assembly consists of an array of fuel rods, spacer grids, guide thimbles, instrumentation tubes, and top and bottom nozzles. In PWR (Pressurized light Water Reactor) fuel assemblies, the spacer grids support the fuel rods by the friction forces between the fuel rods and springs/dimples. Under irradiation, the spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow, and also bear static and dynamic loads during operation inside the nuclear reactor and transportation for spent fuel storage. Thus, it is important to understand the characteristics of deformation behavior and the change in structural strength of an irradiated spacer grid.. In the present study, the static compression test of a spacer grid was conducted to investigate the structural strength of the irradiated spacer grid in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. To evaluate the structural strength of an irradiated spacer grid, hot cell tests were carried out at IMEF of KAERI. The fuel assembly was dismantled and the irradiated spacer grid was obtained for the compression test. The apparatus for measuring the compression strength of the irradiated spacer grid was developed and installed successfully in the hot cell.

  4. An Experimental Study on the Effects of Co-60 Irradiation on the Rat Tongue Tissue

    Lee, Seon Kee; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1990-02-15

    It is known that radiation therapy is a kind of treatment choices of the maxillofacial tumors. This study is designed to investigate the effects of irradiation on rat's tongue tissues as functional tissues which relate to taste, mastication, and pronunciation. 88 rats (Sprague Dawley branch, male) were divided into control group of 4 and experimental group of 84. Experimental group was singly exposed to Co-60 irradiation with 8, 13, 18 Gy in the head and neck region. Animals were sacrificed on 1 hour, 3 hours, 6 hours, 1 day, 3 days, 7 days, and 28 days after the irradiation. The specimens were observed by histopathological examination employing H-E stain and Van-Gieson stain. The results were follows; 1. The tongue tissue were severely swollen on the 1 hour after irradiation, but gradually decreased in course of time. 2. The basal cells of epithelium of tongue proliferated at initial stage of irradiation, but gradually decreased. The Keratin layer were gradually increased. 4. The tissue changes after irradiation were gradually increased by the degree of irradiation.

  5. Comparative study of native and irradiated crotoxin. Biochemical and pharmacological effects

    Nascimento, N. do.

    1991-01-01

    Ionizing radiation is able to detoxify several venoms, including snake venom, without affecting significantly their antigenic and immunogenic properties. In order to elucidate this phenomena, we conceived a comparative biochemical and pharmacological study between native and gamma irradiated (2000Gy) crotoxin, main toxin of south american rattlesnake Crotalus durissus terrificus. Crotoxin was isolated and purified from crude venom by molecular exclusion chromatography, pI precipitation and then irradiated. Immunodiffusion, electrophoresis and gel filtration showed that the molecular integrity was preserved after irradiation with some higher molecular weight aggregate formation and maintenance of its antigenic capacity. The antibodies induced by irradiated toxin had a similar titer to the antibodies induced by native crotoxin; however with higher protective effects in mice. Crotoxin toxicity became 15 times lower after irradiation, as determined by LD sub(50) in mice. Native and irradiated crotoxin biodistribution occurred with a similar general pattern, with renal elimination. In contrast to irradiated crotoxin, the native crotoxin is initially retained in kidneys. A later concentration (2-3hs) occurs in phagocyticmononuclear cells rich organs (liver and spleen) and neural junctions rich organs (muscle and brain). (author)

  6. Study on the inactivation of intracellular enzyme molecules by X-ray irradiation

    Lee, S.B.

    1977-01-01

    Inactivation of the glutamic acid dehydrogenase and glucose-6-phosphate dehydrogenase enzyme molecules in the Ehrlich ascites tumor cells of the mouse were studied. The above mentioned intracellular enzyme molecules were irradiated by the X-ray radiation under the condition of 65 kV, 1 Amp under the atmosphere of nitrogen gases and by 4 0 C. Thereby, irradiation doses were 580 KR/min(error: +-3%). After irradiation, the cell homogentes were prepared through liquid air techniques. There after, the activities of the enzymes were measured with photometric method given by O. Warburg and W. Christian. The dose effect curves of the activities of the two enzymes by the X-ray irradiation showed both exponential and the inactivation doses were 6.5x10 6 and 5.0x10 6 R respectively. These results showed one side that the inactivation process of the intracellular enzyme molecules was one hit reaction after target theory, and the other side that this inactivation process could not be the primary causes of the death through X-ray irradiation of the vertebrate animals, because of the high resistance of the intracellular protein molecules against X-ray irradiation. The one hit reaction by the inactivation process of the irradiated intracellular enzyme molecules was discussed. (author)

  7. A Study on Cell Size of Irradiated Spacer Grid for PWR Fuel

    Jin, Y. G.; Kim, G. S.; Ryu, W. S. and others

    2014-01-01

    The spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow, and grid spring force decreases under irradiation. This reduction of contact force might cause grid-to-rod fretting wear. The fretting failure of the fuel rod is one of the recent significant issues in the nuclear industry from an economical as well as a safety concern. Thus, it is important to understand the characteristics of cell spring behavior and the change in size of grid cells for an irradiated spacer grid. In the present study, the dimensional measurement of a spacer grid was conducted to investigate the cell size of an irradiated spacer grid in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. To evaluate the fretting wear performance of an irradiated spacer grid, hot cell tests were carried out at IMEF of KAERI. Hot cell examinations include dimensional measurements for the irradiated spacer grid. The change of cell sizes was dependent on the direction of the spacer grids, leading to significant gap variations. It was found that the change in size of the cell springs due to irradiation-induced stress relaxation and creep during the fuel residency in the reactor core affect the contact behavior between the fuel rod and the cell spring

  8. Studies on combination effects of peplomycin and x-ray irradiation

    Munenaga, Yasuichi

    1984-01-01

    In order to study effects and methods of combination of peplomycin (PEP) and x-ray irradiation, inhibitory effects on DNA synthesis were investigated with synchronized cells from the parotid gland of mice treated with isoproterenol (IPR) and inhibitory effects on cell proliferation were investigated with Ehrlich solid tumor cells. PEP had dose-dependent effects on the inhibition of DNA synthesis and on the prolongation of cell cycles in the IPR-treated mouse cells. When 3.0 and 5.0 mg/kg of PEP were combined with 200 rad of x-ray irradiation at the early phase of G 1 , synergistic effects on the inhibition of DNA synthesis were seen. This was most noted in the group with PEP 30 minutes before irradiation. PEP had also dose-dependent inhibitory effects on the proliferation of Ehrlich solid tumor cells. This was increased when x-ray irradiation was combined with PEP. Inhibitory effects on the proliferation of tumor cells were greater when PEP was given before x-ray irradiation than after x-ray irradiation, regardless of the amount. The greatest effect was seen in the group with PEP 30 minutes before irradiation, as well as in the experiment with IPR-treated mouse cells. (Namekawa, K.)

  9. Clinical and experimental studies on the sensorineural hearing loss caused by irradiation

    Yamamoto, M [Kobe Univ. (Japan). School of Medicine

    1979-08-01

    In our study, 43 patients whose ears were presumably irradiated, were examined periodically before and after the irradiation; 10 were found to be affected by the sensorineural hearing loss, and these 10 were classified into two types. Type I; Patients of this group had a hearing impairment during or soon after irradiation and usually revealed marked deterioration of bone conduction in high frequencies accompanied by worsening of air conduction in low frequencies. The impaired hearing of this group soon recovered to the pre-treatment level. Type II; Patients of this group developed a slow progressive sensorineural hearing loss. They noticed the deafness with tinnitus several months after irradiation. To clarify the mechanism of the sensorineural hearing loss, histopathological investigations were done using nembutal anesthetized guinea pigs which were irradiated in the confined ear region unilaterally. We also examined histopathologically one human temporal bone belonging to a patient who had been irradiated for middle ear carcinoma. The histopathology of the guinea pigs and human case revealed the following conclusions: Type I hearing loss may be caused by toxic labyrinthitis secondary to the radiation otitis media or by the aseptic labyrinthitis as the result of hyperemia and increased permeability of the irradiated blood vessels in the cochlea. Type II hearing loss may be caused by the late rediation response of the cochleal blood vessels i.e. by the vasculitis which gives rise to obliteration of the vascular lumen and affects the blood supply of the hair cells.

  10. Clinical and experimental studies on the sensorineural hearing loss caused by irradiation

    Yamamoto, Matsunori

    1979-01-01

    In our study, 43 patients whose ears were presumably irradiated, were examined periodically before and after the irradiation; 10 were found to be affected by the sensorineural hearing loss, and these 10 were classified into two types. Type I; Patients of this group had a hearing impairment during or soon after irradiation and usually revealed marked deterioration of bone conduction in high frequencies accompanied by worsening of air conduction in low frequencies. The impaired hearing of this group soon recovered to the pre-treatment level. Type II; Patients of this group developed a slow progressive sensorineural hearing loss. They noticed the deafness with tinnitus several months after irradiation. To clarify the mechanism of the sensorineural hearing loss, histopathological investigations were done using nembutal anesthetized guinea pigs which were irradiated in the confined ear region unilaterally. We also examined histopathologically one human temporal bone belonging to a patient who had been irradiated for middle ear carcinoma. The histopathology of the guinea pigs and human case revealed the following conclusions: Type I hearing loss may be caused by toxic labyrinthitis secondary to the radiation otitis media or by the aseptic labyrinthitis as the result of hyperemia and increased permeability of the irradiated blood vessels in the cochlea. Type II hearing loss may be caused by the late rediation response of the cochleal blood vessels i.e. by the vasculitis which gives rise to obliteration of the vascular lumen and affects the blood supply of the hair cells. (author)

  11. Study of homing patterns of x-irradiated murine lymphoid cells

    Crouse, D.A.

    1974-01-01

    Effects of in vitro x-ray exposure of murine lymphoid cells on their subsequent in vivo homing patterns were studied. The homing of lymphoid cells to various tissues and organs was followed by using radio-labeled cell preparations or by following the distribution of cells with a specific immunological memory. X irradiation of 51 Cr-labeled spleen, lymph node, bone marrow, or thymus cells was found to significantly alter their subsequent in vivo distribution. Irradiated cells demonstrated an increased distribution to the liver and a significantly lower retention in the lungs. Cells going to the lymph nodes of Peyer's patches showed a significant exposure dependent decrease in homing following irradiation. Irradiated lymph node cells homed in greater numbers to the spleen and bone marrow, while irradiated cells from other sources showed a decrease or no change indistribution to the same tissues. Lymph node cell suspensions from dinitrophenyl-bovine gamma globulin (DNP-BGG) immune LBN rats were prepared, irradiated (0 and 200 R) and injected into intermediate (LBN) hosts and controls. Irradiated memory cells provided a secondary antibody response, which was delayed but not suppressed when compared to unirradiated cells. Alteration in homing of lymphocytes caused by various physical and chemical agents was a result of effects on cell membrane characteristics which controlled some aspects of the phenomenon. Radiation (100 to 200 R) may have had a similar effect or it may have resulted in the selective elimination of a population of cells. (U.S.)

  12. A study of the photodegradation of leukotriene B4 by ultraviolet irradiation (UVB, UVA)

    Millar, B.; Green, C.; Ferguson, J.; Raffle, E.J.; Macleod, T.M.

    1989-01-01

    In view of the presence of the polymorphonuclear leukocyte (PMN) chemoattractant Leukotriene B 4 (LTB 4 ) in surface scale of the psoriatic lesion and the known therapeutic effect of phototherapy in psoriasis, the photostability of LTB 4 was investigated. LTB 4 was irradiated with UVB (290-320 nm) from 100-1500 mJ cm -2 and UVA (320-400 nm) from 5-40 J cm -2 . Topical application of UVB irradiated LTB 4 to forearm skin of normal volunteers showed marked reduction in cutaneous erythema, paralleled by reduced transepidermal PMN migration compared with sites of application of unirradiated and UVA irradiated LTB 4 . High performance liquid chromatography (HPLC) demonstrated a dose-dependent photodegradation of LTB 4 by UVB irradiation. UVA irradiation produced no such effect. The wavelengths responsible lie within the absorption spectrum of LTB 4 . In vitro chemotaxis studies, using an under agarose technique, showed a statistically significant reduction in the migration of PMN from psoriatic and non-psoriatic subjects to the UVB irradiated LTB 4 compared with unirradiated LTB 4 , whilst UVA irradiated LTB 4 produced a normal PMN chemotactic response. (author)

  13. A study of the physiological changes and the nutritional qualities of irradiated apples and the effect of irradiation on apples stored at room temperature

    Wang Chuanyao; Jiang Mengyue; Gao Meixu; Ma Xiuye; Zhang Shufen; Liu Shucheng

    1993-01-01

    The effects of γ-irradiation on the metabolism and nutritional qualities of Golden Delicious apples and on the lethality of pathogenic fungi have been studied. The storage effect of irradiation on apples at room temperature has been observed. Results showed that the respiratory intensity of irradiated apple at 0.3-0.5 kGy was near or lower than that of unirradiated apple after 15 days irradiation. The amount of ethylene release was obviously inhibited when fruits were irradiated with 0.3-0.7 kGy. The flesh firmness of apples irradiated with 0.3-0.9 kGy was higher than that of unirradiated apple with increased storage time. The negative correlations between the flesh firmness and the activities of pectinesterase (PE), polygalacturonase (PG) were observed when the dosage was lower than 1.5 kGy. The 2.0 kGy irradiation damaged the ultrastructure of cells, induced the softening of apple. When apples were irradiated with 0.7-2.0 kGy, the contents of 4 important volatile components of apple would be decreased. However, this dose had no effects on the pure chemicals. Studies showed that there was no significant effect of irradiation with 0.3-2.0 kGy on the nutritional qualities of apples and this dose range could effectively control the verticillate pathogenic fungi. The result of storage experiment showed that rotting of fruits decreased by 0.3-0.9 kGy irradiation. (author)

  14. Utilization of the higher plants in a study on hereditary effect of low-dose irradiation

    Yamashita, Jun

    1976-01-01

    Some problems in a study of hereditary effect of low-dose irradiation, which used the higher plants (tradescantia, peas, etc.) as materials, were mentioned. Conditions to be used as materials were mentioned as follows: 1) the materials must have high radio-sensitivity, 2) the natural mutation of the materials must be low, 3) hereditary uniformity and stability of genes in the materials were important, and 4) in case of considering the materials as environmental radiation monitors, the observation period must be long and the duration from exposure to detection of mutation must be short. Tradescantia has most of these conditions, but the greatest fault is that the object of its observation is mutation of somatic cells, and hereditary study is impossible. Therefore, it is necessary to find out other materials in order to solve the problem whether there is a difference in relative frequency of chromosomal abnormalities, which occurrs in germinal cells and is transmitted to posterity, between low and high doses or not. (Serizawa, K.)

  15. An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle

    Evans, Louise G [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Tobin, S. J. [Los Alamos National Laboratory; Menlove, H. O. [Los Alamos National Laboratory; Schear, M. A. [Los Alamos National Laboratory; Worrall, Andrew [U.K. NNL

    2011-01-13

    Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/ or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

  16. Irradiation-related amorphization and crystallization: In situ transmission electron microscope studies

    Allen, C.W.

    1994-01-01

    Interfacing an ion accelerator to a transmission electron microscope (TEM) allows the analytical functions of TEM imaging and diffraction to be employed during ion-irradiation effects studies. At present there are twelve such installations in Japan, one in France and one in the US. This paper treats several aspects of in situ studies involving electron and ion beam induced and enhanced phase transformations and presents results of several in situ experiments to illustrate the dynamics of this approach in the materials science of irradiation effects. The paper describes the ion- and electron-induced amorphization of CuTi; the ion-irradiation-enhanced transformation of TiCr 2 ; and the ion- and electron-irradiation-enhanced crystallization of CoSi 2

  17. A review of semi-pilot scale study on the irradiation of rice in Malaysia

    Norimah Yusof; Razley Mohamad Nordin.

    1986-08-01

    A semi-pilot scale study of milled-rice preservation using gamma irradiation project was started in 1984. The project was aimed to study the possibility of using irradiation in reducing losses during storage. Rice samples were subjected to doses ranging from 0.2 to kGy and stored in stack under conditions similar to a typical rice godown. Rice sampling was done every three to six months to determine the effect of gamma irradiation over 2 years of storage. After 9 months storage, radiation was found to reduce insect infestation with no effect on nutritional value (P 0.05) i.e. reducing sugar, water content, amino acid profile and fat acidity. However gel viscosity was markedly reduced with increase in radiation dose and storage time. Packaging materials (gunny sack, heavy duty plastic, woven laminated and woven non-laminated plastic) did not influence both chemical and physical quality of irradiated stored rice. (author)

  18. Economic study for the establishment of A food irradiation facility at port said harbour

    EL-Gameel, E.A.

    2004-01-01

    The present study discusses the economic aspects of establishing food irradiation facility at Port Said harbour and the effect of various parameters on the unit processing costs. The study is concerned with carrying out an economic evaluation for the application of food exports from Port Said harbour and the marketing and technical aspects where the suitable commodity mix has been determined for the agricultural crops which were proposed for irradiation. The investment criteria utilized for commercial evaluation were internal rate of return (IRR) and pay back period (PEP). The irradiation cost and the additional income are also discussed. The results of this analysis showed that the establishment of food irradiation unit in Port Said harbour in Egypt would be economically feasible

  19. Studies on irradiated BNFL culture medium for decontamination and longer storage

    Singh, Antaryami; Malodia, P.; Jain, S.K.; Ram Gopal

    2001-01-01

    The feasibility of gamma radiation for microbial decontamination and shelf-life extension of culture medium was studied. Changes in total viable count, coliform count and fungal count on exposure to 5, 10, 15, 20 and 25 kGy of gamma radiation were examined. The total viable counts were reduced on irradiation. Complete destruction of bacterial and fungal contamination was observed at 20 kGy. Studies were conducted to examine the changes in microbial contamination of the medium during storage. There was no post irradiation proliferation of microorganisms. Also, no significant change in the efficiency of the irradiated culture medium was observed. Thus, irradiation is extremely useful for longer storage and quality-assurance. (author)

  20. Study of the effect of gamma irradiation on phenolic compounds and pesticides residues

    Fkih, Sana

    2007-01-01

    The aim of this study was to show the effects of this process of conservation on the polyphenol rate and the antioxidant capacity of polyphenols of quince, of the cocoa and those of sage, then to study its effects on the pesticides residues in the sage sheets. The irradiation of quince polyphenols, increased the polyphenols rate as well as the antioxidant capacity. In the case of cocoa polyphenols, we don't have ace observed many differences between the irradiated and not irradiated samples, and in the case of sage polyphenols, the polyphenol rate as well as the antioxidant capacity decreased. Finally, irradiation of parathion caused degradation of this molecule, and the polyphenol rate as well as the antioxidant capacity pf polyphenols of the sheets of sage soaked with parathion was a less decreased than polyphenols of the sheets not soaked with parathion. (Author). 37 refs

  1. Positron lifetime and Doppler broadening study of defects created by swift ion irradiation in sapphire

    Liszkay, L.; Gordo, P.M.; Lima, A. de; Havancsak, K.; Skuratov, V.A.; Kajcsos, Z.

    2004-01-01

    Swift ions create a defect profile penetrating deep into a solid compared to the sampling range of typical slow positron beams, which may consequently study a homogeneous zone of defected materials. To investigate the defect population created by energetic ions, we studied α-Al 2 O 3 single crystals irradiated with swift Kr ions by using conventional and pulsed positron beams. Samples irradiated with krypton at 245 MeV energy in a wide fluence range show nearly saturated positron trapping above 5 x 10 10 ions cm -2 fluence, indicating the creation of monovacancies in high concentration. At 1 x 10 14 ions cm -2 irradiation a 500 ps long lifetime component appears, showing the creation of larger voids. This threshold corresponds well to the onset of the overlap of the damage zones after Bi ion irradiation along the ion trajectories observed with microscopic methods. (orig.)

  2. Preliminary study on detection of irradiated foodstuffs from the Romanian market

    Cutrubinis, Mihalis; Chirita, Daniel; Savu, Diana; Elisabeta Secu, Corina; Mihai, Radu; Secu, Mihai; Ponta, Corneliu

    2007-01-01

    In order to fulfil the European task for market survey in food irradiation the first Romanian laboratory for detection of irradiated foodstuffs was established at IRASM Irradiation Centre. In this preliminary study, a wide range of Romanian food samples (spices, vegetables and meat) gamma irradiated at IRASM have been studied using different detection methods: (1) DNA comet assay, (2) thermoluminescence (TL) and (3) electron spin resonance (ESR) for foodstuffs containing bone or cellulose. The results suggest that there is no general available detection method and there is no perfect detection method. In conclusion, in order to carry out a correct identification of radiation treatment of a food sample it is recommended to use at least two standardised detection methods

  3. Study of cancer-specific chimeric promoters induced by irradiation

    Xiong Jie; Zhou Yunfeng; Sun Wenjie; Wang Weifeng; Liao Zhengkai; Zhou Fuxiang; Xie Conghua

    2010-01-01

    Objective: To combine the radio-inducible CArG element with cancer-specific human telomerase reverse transcriptase (hTERT) gene promoter, and to construct the novel chimeric promoters. Methods: The synthetic hTERT promoters containing different number of radio-inducible CArG elements were constructed, and the activities of the promoters in the cancer cells (HeLa, A549, and MHCC97 cells) and nomal cells (hEL cells) were detected by using luciferase-reporter assays after the treatment of irradiation (a single or fractionated irradiation dose). Results: Synthetic promoter containing 6 repeated CArG units was better in radio-inducibility than any other promoters containing different number of CArG units, and nearly maximum levels obtained at 4-6 Gy. The very low activities of the chimeric promoters could be detected in normal hEL cells. A similar level of reporter gene expression was observed after 3 fractionated doses of 2 Gy compared with a single dose of 6 Gy in cancer cells. Conclusions: The cancer-specific chimeric promoter containing 6 CArG elements showes the best radio-response, and the chimeric promoter system has the potential in cancer gene therapy. (authors)

  4. Studies on Microbiological and Biological Methods for Detection of Irradiated Food

    Ibrahim, H.M.A.

    2013-01-01

    The main aim of this study is to evaluate a microbiological and biological methods used for the detection of irradiated foods in Egypt. The microbiological methods included were shift in microflora load and direct epifluroescent filter technique compared with aerobic plate count (DEFT/APC), while the biological method was DNA comet assay. The selected foods were black, strawberry, fresh-and frozen-de boned chicken. The samples of these foods were exposed to different doses of gamma radiation according to the purpose of irradiation for each food. The results indicated that the characteristics of microbial population of all irradiated samples have been changed. The very lower count of viable bacterial count (APC) and mold and yeasts counts in the samples than the reported normal count as well as the absence of Gram- negative bacteria and Enterobacteriaceae group from these samples could be used as an indication for radiation treatment of these foods. The large difference between microbial counts obtained by DEFT test and that obtained by APC test could also be used for screening radiation treatment of these foods. Photographic and image analysis of DNA comet assay showed that irradiation of these foods caused damage to the food cells DNA (fragmentation) at different levels according to the doses used and kind of foods. This DNA damage can be followed or described by DNA comet assay test. On the basis of comet assay, the discrimination between unirradiated and irradiated food samples was very possible. In general the results showed that DEFT/APC method had the potential to detect irradiated food samples either at zero time of storage or throughout the storage period post- irradiation. DNA comet assay as a rapid, simple and inexpensive screening test approved to be successful for detection of irradiated food samples under investigation. Determination of rough applied irradiation dose is possible if photographic analysis is combined with image analysis

  5. Experimental study on the effect of x-irradiation in the rat periodontal ligament

    Cho, Won Pyo; You, Dong Soo

    1980-01-01

    The author studied on the effects of X-ray irradiation to the development of periodontal ligament in gestation rats. They were irradiated in their abdomen with 100, 200 and 300 rads respectively in one shot irradiation with deep radiation therapy equipment(MAXIMAR 250-III). In 7th, 14th, 21th and 28th day after delivery, those new born rats were respectively sacrificed with ether anesthesia and removed of their mandibles. After removal, those mandibles were fixed in 10% neutral buffer formalin, decalcified with 5% trichloroacetic acid for 5 days and embedded with paraffin. Staining was performed with H-E, Van Gieson, Mallory azan, Bielshowsky-Gomori silver stain and Halmi's oxytalan fiber stain. The results were as follows: 1. Before tooth eruption, all the fiber components in dental sac were almost always oriented near the outer enamel epithelial layer. But in irradiated new born rats, those collagen fiber orientation was more irregular than those of control groups, and this phenomenon was more severe in proportion to the amount of irradiation in the gestation period. 2. Before tooth eruption, the connective tissue fibers in periodontal ligament were stained with lighter in the irradiated groups than those of control groups. Oxytalan fibers of irradiated groups were thin and splitting pattern of their fiber morphology to compare with those of control groups. 3. After tooth eruption, the periodontal ligament fibers of irradiated groups were oriented functionally and their morphology was thick, fine and heavy staining. Oxytalan fibers were revealed with oblique parallel arrangement in the periodontal ligament of irradiated groups.

  6. Scrotal Irradiation in Primary Testicular Lymphoma: Review of the Literature and In Silico Planning Comparative Study

    Brouwer, Charlotte L.; Wiesendanger, Esther M.; Hulst, Peter C. van der; Imhoff, Gustaaf W. van; Langendijk, Johannes A.; Beijert, Max

    2013-01-01

    We examined adjuvant irradiation of the scrotum in primary testicular lymphoma (PTL) by means of a literature review in MEDLINE, a telephone survey among Dutch institutes, and an in silico planning comparative study on scrotal irradiation in PTL. We did not find any uniform adjuvant irradiation technique assuring a safe planning target volume (PTV) coverage in published reports, and the definition of the clinical target volume is unclear. Histopathologic studies of PTL show a high invasion rate of the tunica albuginea, the epididymis, and the spermatic cord. In retrospective studies, a prescribed dose of at least 30 Gy involving the scrotum is associated with best survival. The majority of Dutch institutes irradiate the whole scrotum without using a planning computed tomography scan, with a single electron beam and a total dose of 30 Gy. The in silico planning comparative study showed that all evaluated approaches met a D 95% scrotal dose of at least 85% of the prescription dose, without exceeding the dose limits of critical organs. Photon irradiation with 2 oblique beams using wedges resulted in the best PTV coverage, with a mean value of 95% of the prescribed dose, with lowest maximum dose. Adjuvant photon or electron irradiation of the whole scrotum including the contralateral testicle with a minimum dose of 30 Gy is recommended in PTL. Computed tomography-based radiation therapy treatment planning with proper patient positioning and position verification guarantees optimal dose coverage.

  7. Studies on rate equations for defects in irradiated solids using the local analysis method

    Carvalho e Camargo, M.U. de.

    1983-10-01

    The void formation and swelling phenomenon in material for nuclear reactors structures, mainly for fast reactors, has been studied by several authors. A simple calculation covering the basic instance of radiation damage in irradiated solid solution, using the local analysis in rate theory is presented here. A simple description of pratical and fundamental interest for the complex problem of solid solution under irradiation is given. (Author) [pt

  8. Study on irradiation conditions of producing 153Sm with natural abundance samarium target

    Du Jin; Jin Xiaohai; Bai Hongsheng; Liu Yuemin; Chen Daming; Wang Fan

    1998-01-01

    Irradiation conditions of natural abundance 152 Sm targets in different forms are studied in the heavy water reactor and the light water swimming pool reactor at the China Institute of Atomic Energy. The result shows that the specific activity of 153 Sm in liquid form target irradiated in the light water swimming pool reactor is two times greater than that in solid form target. The radionuclide purity of 153 Sm is more than 99%, which can meet the needs of clinical application

  9. Study of an integrated electronic monitor for neutron beams

    Barelaud, B.; Nexon-Mokhtari, F.; Barrau, C.; Decossac, J.L.; Vareille, J.C.; Sarrabayrouse, G.

    1994-01-01

    Many neutron beams monitors in 10 keV - 50 keV range are perturbed by gamma radiation impact. This new monitor uses two silicon (junction) diodes operating coincidence detection, combined with an electronic threshold to eliminate gamma background noise. The results and analyses presented here only concern feasibility studies. (D.L.)

  10. Study of an integrated electronic monitor for neutron beams

    Barelaud, B.; Nexon-Mokhtari, F.; Barrau, C.; Decossac, J.L.; Vareille, J.C. [Limoges Univ., 87 (France); Sarrabayrouse, G. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Lab. d`Automatique et d`Analyse des Systemes

    1994-12-31

    Many neutron beams monitors in 10 keV - 50 keV range are perturbed by gamma radiation impact. This new monitor uses two silicon (junction) diodes operating coincidence detection, combined with an electronic threshold to eliminate gamma background noise. The results and analyses presented here only concern feasibility studies. (D.L.). 11 refs.

  11. A study of morphogenesis of digital malformation on rat embryo by x-irradiation

    Kim, Jhai Dhuck; You, Dong Soo

    1981-01-01

    The author studied in the effects of x-irradiation to the development of digital malformation in gestation rats. The time-matings occurred between 6 p.m. and 8 a.m. and females with copulation plugs at 8 a.m. were isolated and properly marked for evidence of copulation. The lower abdomen of mothers were exposed to x-irradiation on the 11 1/2th day of gestation, the critical period developing digital malformation, respectively 100, 150, 200, 250, 300 and 350 rads. At 18 1/2th day of post-conception total 50 pregnant females were dissected and the incidence of digital malformations were obtained. Rat embryos on the 12, 13, 14, 15, 16th day of gestation irradiated by 250 rads were examined for morphogenesis of digital malformation. Digital radiating lines were examined in water and histologically by H-E stain. Supra vital stain samples by Nile-blue sulfate in 37 .deg. C normal saline were prepared for the observation of cell necrosis regions and morphogenesis of digits. The results obtained were as follows; 1. By x-irradiation on 11th day of gestation, digital malformations of Ectrodactylia, Syndactylia, Polydactylia and Hematodactylia were developed. Ectrodactylia showed the effective relationship to the amount of irradiation, however Syndactylia and Poydactylia did not. 2. By x-irradiation, cell necrosis of digital germ was appeared markedly, but in 48 hours after irradiation was depressed to the periphery of digital germ and in 72 hours after irradiation was disappeared. Digital radiating line showed marked state of malformation in 48 hours after irradiation and continued to show the same amount of physiological cell necrosis as the compared control group in 72 hours after irradiation. But in the Syndactylia, physiological cell necrosis was not able to be recognized. 3. Ectrodactylia induced by x-irradiation was considered as the direct result of cell necrosis of digital origin, however, Polydactylia and Syndactylia were considered as the result of some effect in

  12. Studies on the ability of irradiated Escherichia coli bacteria to reactivate X-ray inactivated bacteriophages

    Kiessling, W.

    1980-01-01

    The Weigle Reactivation phenomenon ie. the observation that low UV-flow irradiated bacteria increase the survival rate of UV-irradiated phages has not, to date, been studied with other forms of irradiation as inducers. In the studies reported here lambda-phages and E. coli cells in LB-medium were treated with X-rays. Host cells treated with an X-ray dose from 85 to 765 Gy showed a reactivation factor of 1.3 to 3.0 for X-ray inactivated phages. The capacity of the bacteria for phage reproduction did not appear to be markedly diminished. A reactivation factor of 1.3 only was found for X-irradiated phages when host cells were treated with UV-irradiation. The low Weigle reactivation of X-ray treated phages compared to UV-treatment was found to be due to a diminished absorption capacity, as demonstrated by the determination of free non-absorbed phages by filtration of radioactive-labelled phage-host-complexes. Reactivation studies on X-irradiated phages with various host bacteria of different radiation sensitivities confirm this finding. (orig.) [de

  13. Irradiation effect on antifungal potential Myristica fragrans (nutmeg) essential oil, a preliminary study

    Duarte, Renato C.; Fanaro, Gustavo B.; Koike, Amanda C.R.; Villavicencio, Anna Lucia C.H., E-mail: gbfanaro@ipen.b, E-mail: amandaramos@usp.b, E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Myristica fragrans (nutmeg) is any of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, an evergreen tree indigenous to the Banda Islands in the Moluccas of Indonesia, or Spice Islands. Widely used as a food condiment and flavoring, used in perfumery and medicine. The nutmeg has many biological properties as analgesic, antiseptic, antispasmodic, aphrodisiac, astringent, carminative, haemostatic, insecticidal and parasiticide. Previous research has revealed interesting antimicrobial effect of nutmeg essential oil. Spices irradiation is a worldwide process used and this technique is an effective pathogenic microorganisms control providing consumers food security. By the fact nutmeg not only used in food, but also as an essential oil raw material this study investigated the nutmeg different irradiation doses influence on the possible antimicrobial potential oil. The aim of this study was evaluate the antifungal potential oil from unirradiated and irradiated nutmeg in the fungus Guignardia citricarpa that causes serious damage in orange plantations. The Myristica fragrans samples were irradiated in {sup 60}Co irradiator at doses of 5.0 and 10.0 kGy. The oil was used in 50 and 100% of concentration (irradiated and not irradiated). The essential oil in high concentration could be a good substitute for the pesticides used to control the fungus Guignardia citricarpa, the nutmeg irradiation treatment with the doses 5.0 and 10.0 kGy did not changed the results in the essential oil effectiveness. It is clear that is necessary others studies with others doses to verify the radiation ionizing influence in the essential oil activity and the oil application efficiency in the field against the fungus. (author)

  14. Irradiation effect on antifungal potential Myristica fragrans (nutmeg) essential oil, a preliminary study

    Duarte, Renato C.; Fanaro, Gustavo B.; Koike, Amanda C.R.; Villavicencio, Anna Lucia C.H.

    2011-01-01

    The Myristica fragrans (nutmeg) is any of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, an evergreen tree indigenous to the Banda Islands in the Moluccas of Indonesia, or Spice Islands. Widely used as a food condiment and flavoring, used in perfumery and medicine. The nutmeg has many biological properties as analgesic, antiseptic, antispasmodic, aphrodisiac, astringent, carminative, haemostatic, insecticidal and parasiticide. Previous research has revealed interesting antimicrobial effect of nutmeg essential oil. Spices irradiation is a worldwide process used and this technique is an effective pathogenic microorganisms control providing consumers food security. By the fact nutmeg not only used in food, but also as an essential oil raw material this study investigated the nutmeg different irradiation doses influence on the possible antimicrobial potential oil. The aim of this study was evaluate the antifungal potential oil from unirradiated and irradiated nutmeg in the fungus Guignardia citricarpa that causes serious damage in orange plantations. The Myristica fragrans samples were irradiated in 60 Co irradiator at doses of 5.0 and 10.0 kGy. The oil was used in 50 and 100% of concentration (irradiated and not irradiated). The essential oil in high concentration could be a good substitute for the pesticides used to control the fungus Guignardia citricarpa, the nutmeg irradiation treatment with the doses 5.0 and 10.0 kGy did not changed the results in the essential oil effectiveness. It is clear that is necessary others studies with others doses to verify the radiation ionizing influence in the essential oil activity and the oil application efficiency in the field against the fungus. (author)

  15. Studies on the separation and purification of uranium from thoria irradiated in PHWR

    Kedari, C.S.; Sinalkar, N.; Dhami, P.S.; Achuthan, P.V.; Vijayan, K.; Moorthy, A.D.; Jambunathan, U.; Munshi, S.K.; Dey, P.K.

    2005-10-01

    About 5 g of thoria pellet extracted from the thoria bundle irradiated to 508 full power days in PHWR at KAPS and cooled for about 4.5 years was dissolved in 25 mL of 13 M HNO 3 containing 0.03 M HF and 0.1 M Al(NO 3 ) 3 under reflux condition in a shielded glove box. Thorium concentration and acidity of the dissolved solution was adjusted to ∼97 g/L and 4M HNO 3 , suitable for solvent extraction studies. The feed solution had a uranium concentration of 1.36 g/L and gross gamma activity of ∼6 Ci/L. Liquid-liquid extraction experiments were carried out in batch with this feed using 3% TBP in n-dodecane as extractant. The uranium product solution obtained from the solvent extraction was further purified by ion-exchange method using cation exchange resin Dowex 50 x 4. Fission product activity and the isotopic composition of the final recovered product were measured. The uranium product had an overall decontamination factor of 10 4 and 2 x 10 4 with respect to thorium and fission product activity respectively. A part of the solution was monitored for dose build-up due to the growth of the decay products of 232 U which is a vital input for designing the shielding of a 233 U separation facility. (author)

  16. High-dose irradiation: Wholesomeness of food irradiated with doses above 10 kGy. Report of a joint FAO/IAEA/WHO study group

    1999-01-01

    This report presents the recommendations of an international group of experts convened by the World Health Organization, in association with the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, to consider the implications of food irradiated to doses higher than those recommended in 1980 by the Joint Expert Committee on the Wholesomeness of Irradiated Food. Irradiation ensures the hygienic quality of food and extends shelf-life. The public perception of the safety of food irradiation has generally precluded its widespread use. However, current applications of food irradiation to doses over 10 kGy have been in the development of high-quality shelf-stable convenience foods for specific target groups such as immunosuppressed individuals and those under medical care, astronauts and outdoor enthusiasts. The Study Group reviewed data relating to the toxicological, nutritional, radiation chemical and physical aspects of food irradiated to doses above 10kGy from a wide range and number of studies carried out over the last forty years. This report presents a comprehensive summary, along with references, of the effectiveness and safety of the irradiation process. It concludes that foods treated with doses greater than 10kGy can be considered safe and nutritionally adequate when produced under established Good Manufacturing Practice

  17. About the study of irradiation effects on in-core instrumentation

    Angelino, G.

    1972-01-01

    The knowledge of in-core instrumentation performances is a very important item when irradiations of technological interest are concerned. When measurement of small changes in mechanical or thermal properties is of major importance, the effect of neutron and gamma irradiation on various transducers must be thoroughly evaluated. A rig mock-up was irradiated in the Triga Mark II Reactor of the Pavia University to assess the possibility of carrying out a study on irradiation effects on in-core instrumentation. Data on neutron flux distribution and γ-heating effect were collected from this preliminary experiment; at the same time a complete check was performed on rig assembling procedure, on the behaviour under operating conditions, and on the reactor loading and unloading operations. (author)

  18. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P.

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of γ radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [fr

  19. Correlation between electron-irradiation defects and applied stress in graphene: A molecular dynamics study

    Kida, Shogo; Yamamoto, Masaya; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki, E-mail: yasuda@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Tada, Kazuhiro [Department of Electrical and Control Systems Engineering, National Institute of Technology, Toyama College, Toyama 939-8630 (Japan)

    2015-09-15

    Molecular dynamics (MD) simulations are performed to study the correlation between electron irradiation defects and applied stress in graphene. The electron irradiation effect is introduced by the binary collision model in the MD simulation. By applying a tensile stress to graphene, the number of adatom-vacancy (AV) and Stone–Wales (SW) defects increase under electron irradiation, while the number of single-vacancy defects is not noticeably affected by the applied stress. Both the activation and formation energies of an AV defect and the activation energy of an SW defect decrease when a tensile stress is applied to graphene. Applying tensile stress also relaxes the compression stress associated with SW defect formation. These effects induced by the applied stress cause the increase in AV and SW defect formation under electron irradiation.

  20. Study on the effect of food irradiation on some blood serum enzymes in rats

    Metwalli, O.M.

    1977-01-01

    Rats were fed irradiated diets as part of a study of screening tests for the safety of irradiated food. The diet consisted (g/100 g) of casein, 8.5; skim-milk, 9.4; potato starch, 50.00; wheat flour, 16.50; sucrose, 5.00; sunflower oil, 6.00; choline chloride, 0.10; salt mixture, 3.50; and vitamin mix.ure, 1.00. Diets were irradiated at 2.5 or 4.5 Mrad and were fed ad lib. for 4 months. Levels of serum (i) glutanic-pyruvic transaminase, (ii) glutamic-oxalacetic transaminase, and (iii) lactic dehydrogenase were determined. No significant changes were observed in (i) or (iii) on ieeding irradiated diets, or in (ii) for male rats. Significant decreases (P [de