Incoming Shortwave Fluxes at the Surface--A Comparison of GCM Results with Observations.

Science.gov (United States)

Garratt, J. R.

1994-01-01

Evidence is presented that the exam surface net radiation calculated in general circulation models at continental surfaces is mostly due to excess incoming shortwave fluxes. Based on long-term observations from 22 worldwide inland stations and results from four general circulation models the overestimate in models of 20% (11 W m2) in net radiation on an annual basis compares with 6% (9 W m2) for shortwave fluxes for the same 22 locations, or 9% (18 W m2) for a larger set of 93 stations (71 having shortwave fluxes only). For annual fluxes, these differences appear to be significant.

Measurement and modeling of shortwave irradiance components in cloud-free atmospheres

Energy Technology Data Exchange (ETDEWEB)

Halthore, R.N.

1999-08-04

Atmosphere scatters and absorbs incident solar radiation modifying its spectral content and decreasing its intensity at the surface. It is very useful to classify the earth-atmospheric solar radiation into several components--direct solar surface irradiance (E{sub direct}), diffuse-sky downward surface irradiance (E{sub diffuse}), total surface irradiance, and upwelling flux at the surface and at the top-of-the atmosphere. E{sub direct} depends only on the extinction properties of the atmosphere without regard to details of extinction, namely scattering or absorption; furthermore it can be accurately measured to high accuracy (0.3%) with the aid of an active cavity radiometer (ACR). E{sub diffuse} has relatively larger uncertainties both in its measurement using shaded pyranometers and in model estimates, owing to the difficulty in accurately characterizing pyranometers and in measuring model inputs such as surface reflectance, aerosol single scattering albedo, and phase function. Radiative transfer model simulations of the above surface radiation components in cloud-free skies using measured atmospheric properties show that while E{sub direct} estimates are closer to measurements, E{sub diffuse} is overestimated by an amount larger than the combined uncertainties in model inputs and measurements, illustrating a fundamental gap in the understanding of the magnitude of atmospheric absorption in cloud-free skies. The excess continuum type absorption required to reduce the E{sub diffuse} model overestimate ({approximately}3--8% absorptance) would significantly impact climate prediction and remote sensing. It is not clear at present what the source for this continuum absorption is. Here issues related to measurements and modeling of the surface irradiance components are discussed.

Improvements of top-of-atmosphere and surface irradiance computations with CALIPSO-, CloudSat-, and MODIS-derived cloud and aerosol properties

Science.gov (United States)

Kato, Seiji; Rose, Fred G.; Sun-Mack, Sunny; Miller, Walter F.; Chen, Yan; Rutan, David A.; Stephens, Graeme L.; Loeb, Norman G.; Minnis, Patrick; Wielicki, Bruce A.; Winker, David M.; Charlock, Thomas P.; Stackhouse, Paul W., Jr.; Xu, Kuan-Man; Collins, William D.

2011-10-01

One year of instantaneous top-of-atmosphere (TOA) and surface shortwave and longwave irradiances are computed using cloud and aerosol properties derived from instruments on the A-Train Constellation: the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite, the CloudSat Cloud Profiling Radar (CPR), and the Aqua Moderate Resolution Imaging Spectrometer (MODIS). When modeled irradiances are compared with those computed with cloud properties derived from MODIS radiances by a Clouds and the Earth's Radiant Energy System (CERES) cloud algorithm, the global and annual mean of modeled instantaneous TOA irradiances decreases by 12.5 W m-2 (5.0%) for reflected shortwave and 2.5 W m-2 (1.1%) for longwave irradiances. As a result, the global annual mean of instantaneous TOA irradiances agrees better with CERES-derived irradiances to within 0.5W m-2 (out of 237.8 W m-2) for reflected shortwave and 2.6W m-2 (out of 240.1 W m-2) for longwave irradiances. In addition, the global annual mean of instantaneous surface downward longwave irradiances increases by 3.6 W m-2 (1.0%) when CALIOP- and CPR-derived cloud properties are used. The global annual mean of instantaneous surface downward shortwave irradiances also increases by 8.6 W m-2 (1.6%), indicating that the net surface irradiance increases when CALIOP- and CPR-derived cloud properties are used. Increasing the surface downward longwave irradiance is caused by larger cloud fractions (the global annual mean by 0.11, 0.04 excluding clouds with optical thickness less than 0.3) and lower cloud base heights (the global annual mean by 1.6 km). The increase of the surface downward longwave irradiance in the Arctic exceeds 10 W m-2 (˜4%) in winter because CALIOP and CPR detect more clouds in comparison with the cloud detection by the CERES cloud algorithm during polar night. The global annual mean surface downward longwave irradiance of

Variety identification of brown sugar using short-wave near infrared spectroscopy and multivariate calibration

Science.gov (United States)

Yang, Haiqing; Wu, Di; He, Yong

2007-11-01

Near-infrared spectroscopy (NIRS) with the characteristics of high speed, non-destructiveness, high precision and reliable detection data, etc. is a pollution-free, rapid, quantitative and qualitative analysis method. A new approach for variety discrimination of brown sugars using short-wave NIR spectroscopy (800-1050nm) was developed in this work. The relationship between the absorbance spectra and brown sugar varieties was established. The spectral data were compressed by the principal component analysis (PCA). The resulting features can be visualized in principal component (PC) space, which can lead to discovery of structures correlative with the different class of spectral samples. It appears to provide a reasonable variety clustering of brown sugars. The 2-D PCs plot obtained using the first two PCs can be used for the pattern recognition. Least-squares support vector machines (LS-SVM) was applied to solve the multivariate calibration problems in a relatively fast way. The work has shown that short-wave NIR spectroscopy technique is available for the brand identification of brown sugar, and LS-SVM has the better identification ability than PLS when the calibration set is small.

Investigation of food irradiation technology for application to plant quarantine. Working group report of food irradiation technology

Energy Technology Data Exchange (ETDEWEB)

Sunaga, Hiromi; Ito, Hitoshi; Takatani, Yasuyuki; Takizawa, Haruki; Yotsumoto, Keiichi; Tanaka, Ryuichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Hirano, Tsuyoshi; Tokunaga, Okihiro

1999-06-01

The commercialization of food irradiation in Japan was started in 1973 for the sprout inhibition of potatoes as the first successful food irradiation facility in the world. Since approval of potato irradiation, no items has been commercialized in Japan. However, international agreement for phase out of methyl bromide after 2005 and increasing incidences of foodborn diseases such as by Escherichia coli O157:H7 are forcing to have interesting to food irradiation. Takasaki Radiation Chemistry Research Establishment has long experiences on research of irradiation effect and engineering of food irradiation in Japan. From these back ground, working group of food irradiation was organized at August 1997 by some members of Department of Radiation Research for Environment and Resources and Advanced Technology Center for supporting technically on commercialization of food irradiation. This report presents the result of discussion in working group on generalization up to date researches of food irradiation, application fields and items, technical problems and future prospects of this technology in Japan. (author)

Factors affecting projected Arctic surface shortwave heating and albedo change in coupled climate models.

Science.gov (United States)

Holland, Marika M; Landrum, Laura

2015-07-13

We use a large ensemble of simulations from the Community Earth System Model to quantify simulated changes in the twentieth and twenty-first century Arctic surface shortwave heating associated with changing incoming solar radiation and changing ice conditions. For increases in shortwave absorption associated with albedo reductions, the relative influence of changing sea ice surface properties and changing sea ice areal coverage is assessed. Changes in the surface sea ice properties are associated with an earlier melt season onset, a longer snow-free season and enhanced surface ponding. Because many of these changes occur during peak solar insolation, they have a considerable influence on Arctic surface shortwave heating that is comparable to the influence of ice area loss in the early twenty-first century. As ice area loss continues through the twenty-first century, it overwhelms the influence of changes in the sea ice surface state, and is responsible for a majority of the net shortwave increases by the mid-twenty-first century. A comparison with the Arctic surface albedo and shortwave heating in CMIP5 models indicates a large spread in projected twenty-first century change. This is in part related to different ice loss rates among the models and different representations of the late twentieth century ice albedo and associated sea ice surface state. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Resistivity recovery of neutron-irradiated and cold-worked thorium

International Nuclear Information System (INIS)

Tang, J.T.

1976-01-01

Recovery of neutron-irradiated and cold-worked thorium was studied using electrical resistivity measurements. Thorium wires containing 30 and 300 wt ppM carbon were irradiated to fast neutron fluence of 1.3 x 10 18 n/cm 2 (E greater than 0.1 MeV). Another group of thorium wires containing 45, 300 and 600 wt ppM carbon were laterally compressed 5 to 40 percent. Both irradiation and cold-working were performed at liquid nitrogen temperature. The induced resistivity was found to increase with carbon content for both treatments. Isochronal recovery studies were performed in the 120--420 0 K temperature range. Two recovery stages (II and III) were found for both cold-worked and irradiated samples. In all cases the activation energies were determined by use of the ratio-of-slope method. Consistent results were observed for both irradiated and cold-worked specimens within the experimental error in the two stages. Other methods were also used in determining the activation energy of stage III for irradiated samples. All analysis methods indicated that the activation energies decreased with increasing carbon content for differently treated specimens. Possible reasons for such behavior are discussed. The annealing data obtained do not fit a simple chemical rate equation but follow the empirical exponential equation proposed by Avrami. A model of detrapping of interstitials from impurities is suggested for stage II recovery. On the basis of the observed low activation energy and high retention of defects above stage III, a divacancy migration model is proposed for stage III recovery

Evaluation of reproductive function of female rats exposed to radiofrequency fields (27. 12 MHz) near a shortwave diathermy device

Energy Technology Data Exchange (ETDEWEB)

Brown-Woodman, P.D.; Hadley, J.A.; Richardson, L.; Bright, D.; Porter, D.

1989-04-01

In recent years, there has been increased concern regarding effects of operator exposure to the electromagnetic (EM) field associated with shortwave diathermy devices. The present study was designed to investigate the effects, on rats, of repeated exposure to such an EM field. Following repeated exposure for 5 wk, a reduction in fertility occurred as indicated by a reduced number of matings in exposed rats compared to sham-irradiated rats and a reduction in the number of rats that conceived after mating. The data suggest that female operators could experience reduced fertility, if they remained close to the console for prolonged periods. This has particular significant for the physiotherapy profession.

Spatial variability of shortwave radiative fluxes in the context of snowmelt

Science.gov (United States)

Pinker, Rachel T.; Ma, Yingtao; Hinkelman, Laura; Lundquist, Jessica

2014-05-01

Snow-covered mountain ranges are a major source of water supply for run-off and groundwater recharge. Snowmelt supplies as much as 75% of surface water in basins of the western United States. Factors that affect the rate of snow melt include incoming shortwave and longwave radiation, surface albedo, snow emissivity, snow surface temperature, sensible and latent heat fluxes, ground heat flux, and energy transferred to the snowpack from deposited snow or rain. The net radiation generally makes up about 80% of the energy balance and is dominated by the shortwave radiation. Complex terrain poses a great challenge for obtaining the needed information on radiative fluxes from satellites due to elevation issues, spatially-variable cloud cover, rapidly changing surface conditions during snow fall and snow melt, lack of high quality ground truth for evaluation of the satellite based estimates, as well as scale issues between the ground observations and the satellite footprint. In this study we utilize observations of high spatial resolution (5-km) as available from the Moderate Resolution Imaging Spectro-radiometer (MODIS) to derive surface shortwave radiative fluxes in complex terrain, with attention to the impact of slopes on the amount of radiation received. The methodology developed has been applied to several water years (January to July during 2003, 2004, 2005 and 2009) over the western part of the United States, and the available information was used to derive metrics on spatial and temporal variability in the shortwave fluxes. It is planned to apply the findings from this study for testing improvements in Snow Water Equivalent (SWE) estimates.

Shortwave Array Spectroradiometer–Zenith (SASZe) Instrument Handbook

Energy Technology Data Exchange (ETDEWEB)

Flynn, Connor J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-04-01

The Shortwave Array Spectroradiometer – Zenith (SASZe) provides measurements of zenith spectral shortwave radiance at 1Hz over a continuous spectral range from approximately 300 nm to 1700 nm. The SASZe design connects an optical collector located outdoors to a pair of spectrometers and data collections system located indoors within a climate-controlled building via an umbilical cable of fiber optic and electrical cables. The light collector incorporates a collimator yielding a 1-degree Full Width at Half Maximum (FWHM) field of view. The data-acquisition electronics and spectrometers include an in-line fiber optic shutter and two Avantes fiber-coupled grating spectroradiometers within a temperature-controlled container. The Avantes Avaspec ULS 2048 charge-coupled device (CCD) spectrometer covers the wavelength range from about 300-1100 nm with a pixel spacing of less than 0.6 nm and a spectral resolution of about 2.4 nm FWHM. The Avantes Avaspec NIR256-1.7 spectrometer covers the wavelength range from about 950 nm to 1700 nm with a pixel spacing of less than 4 nm and a spectral resolution of about 6 nm FWHM.

Effect of surface albedo, water vapour, and atmospheric aerosols on the cloud-free shortwave radiative budget in the Arctic

Energy Technology Data Exchange (ETDEWEB)

Di Biagio, C. [ENEA, Laboratory for Earth Observations and Analyses, Rome (Italy); University of Siena, Department of Earth Science, Siena (Italy); Di Sarra, A. [ENEA, Laboratory for Earth Observations and Analyses, Rome (Italy); Eriksen, P. [Danish Climate Centre, DMI, Danish Meteorological Institute, Copenhagen (Denmark); Ascanius, S.E. [DMI, Danish Meteorological Institute, Qaanaaq (Greenland); Muscari, G. [INGV, Istituto Nazionale di Geofisica e Vulcanologia, Rome (Italy); Holben, B. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

2012-08-15

This study is based on ground-based measurements of downward surface shortwave irradiance (SW), columnar water vapour (wv), and aerosol optical depth ({tau}) obtained at Thule Air Base (Greenland) in 2007-2010, together with MODIS observations of the surface shortwave albedo (A). Radiative transfer model calculations are used in combination with measurements to separate the radiative effect of A ({Delta}SW{sub A}), wv ({Delta}SW{sub wv}), and aerosols ({Delta}SW{sub {tau}}) in modulating SW in cloud-free conditions. The shortwave radiation at the surface is mainly affected by water vapour absorption, which produces a reduction of SW as low as -100 Wm{sup -2} (-18%). The seasonal change of A produces an increase of SW by up to +25 Wm{sup -2} (+4.5%). The annual mean radiative effect is estimated to be -(21-22) Wm{sup -2} for wv, and +(2-3) Wm{sup -2} for A. An increase by +0.065 cm in the annual mean wv, to which corresponds an absolute increase in {Delta}SW{sub wv} by 0.93 Wm{sup -2} (4.3%), has been observed to occur between 2007 and 2010. In the same period, the annual mean A has decreased by -0.027, with a corresponding decrease in {Delta}SW{sub A} by 0.41 Wm{sup -2} (-14.9%). Atmospheric aerosols produce a reduction of SW as low as -32 Wm{sup -2} (-6.7%). The instantaneous aerosol radiative forcing (RF{sub {tau}}) reaches values of -28 Wm{sup -2} and shows a strong dependency on surface albedo. The derived radiative forcing efficiency (FE{sub {tau}}) for solar zenith angles between 55 and 70 is estimated to be (-120.6 {+-} 4.3) for 0.1 < A < 0.2, and (-41.2 {+-} 1.6) Wm{sup -2} for 0.5 < A < 0.6. (orig.)

Penetrating Shortwave Radiation and Sea Ice Algae feedbacks using the Community Earth System Model

Science.gov (United States)

Arntsen, A. E.; Perovich, D. K.; Bailey, D. A.; Holland, M. M.

2017-12-01

Transmittance of solar radiation through the sea ice cover determines energy transfer to the upper ocean in the form of heat as well as photosynthetically active radiation (PAR) available for the growth of under ice phytoplankton and bottom ice algal communities. A thinning ice cover, increased pond coverage, and earlier melt onset has increased light availability to the upper ocean in contemporary Arctic ice-covered waters. To investigate seasonal and spatial variability of solar shortwave irradiance penetrating the ice cover in the Beaufort and Chukchi Sea regions, we use the fully coupled Community Earth System Model (CESM) in conjunction with a multistream radiative transfer model constrained and initiated by in situ observations. Results inform the importance of light attenuation by ice-based algal pigments within large scale global climate models. We demonstrate the presence of bio-optical feedbacks related to a younger ice cover and examine how these relationships are impacting the trajectory of under ice blooms and the energy budget of the ice-ocean system.

Final Report on Contract DE-AI02-04ER63703

Energy Technology Data Exchange (ETDEWEB)

Joseph Michalsky

2005-12-07

This report includes results for the entire period of this award 9 September 2003 through 14 February 2005. Two contributions were in broadband shortwave irradiance measurements. One included conducting the second diffuse horizontal broadband shortwave irradiance IOP to establish a working standard for diffuse horizontal shortwave irradiance, where none exists. The results are summarized in a paper published in the Journal of Geophysical Research-Atmospheres. Another broadband shortwave effort was in the comparison of clear-sky measurements of broadband diffuse and direct irradiance during the May 2003 Aerosol IOP with six radiative transfer models of direct and diffuse irradiance using aerosol and other data inputs carefully measured during the Aerosol IOP. A paper with the results has been submitted to the Journal of Geophysical Research-Atmospheres; it is in review. A third area of research was in spectral radiative transfer model comparisons made using three models and measurements made with the visible rotating shadowband spectroradiometer (RSS) during the first diffuse irradiance IOP in 2001. Besides these contributions that have resulted in papers and/or presentations, the principal investigator (PI) consulted with science team and infrastructure representatives to improve aerosol optical depth measurements and to produce a spectral surface albedo product.

Luminescence yield in irradiating gases by X-rays and alpha particles

International Nuclear Information System (INIS)

Combecher, D.

1973-01-01

In this paper, the measurable light emission in the irradiation of gases as modle substances has been quantitatively determined. The gases Ar, H 2 , N 2 , air, and C 3 H 8 were irradiated with X-rays and α-particles at a pressure of 730 torr. The emitted light was measured in the spectral range between the short-wave absorption edge of the gases and 6000 A (spectral resolution: 20 A). The spectral light yield was determined from the efficiency of the apparatus and from the total energy absorbed in the gases. (HK) [de

ENSO surface shortwave radiation forcing over the tropical Pacific

Directory of Open Access Journals (Sweden)

K. G. Pavlakis

2008-09-01

Full Text Available We have studied the spatial and temporal variation of the downward shortwave radiation (DSR at the surface of the Earth during ENSO events for a 21-year period over the tropical and subtropical Pacific Ocean (40° S–40° N, 90° E–75° W. The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database, reanalysis data from NCEP/NCAR for the key atmospheric and surface input parameters, and aerosol parameters from GADS (acronyms explained in main text. A clear anti-correlation was found between the downward shortwave radiation anomaly (DSR-A time-series, in the region 7° S–5° N 160° E–160° W located west of the Niño-3.4 region, and the Niño-3.4 index time-series. In this region where the highest in absolute value DSR anomalies are observed, the mean DSR anomaly values range from −45 Wm⁻² during El Niño episodes to +40 Wm⁻² during La Niña events. Within the Niño-3.4 region no significant DSR anomalies are observed during the cold ENSO phase in contrast to the warm ENSO phase. A high correlation was also found over the western Pacific (10° S–5° N, 120–140° E, where the mean DSR anomaly values range from +20 Wm⁻² to −20 Wm⁻² during El Niño and La Niña episodes, respectively. There is also convincing evidence that the time series of the mean downward shortwave radiation anomaly in the off-equatorial western Pacific region 7–15° N 150–170° E, precedes the Niño-3.4 index time-series by about 7 months and the pattern of this anomaly is indicative of ENSO operating through the mechanism of the western Pacific oscillator. Thus, the downward shortwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to assess whether or not El Niño or La Niña conditions prevail.

Arctic atmospheric preconditioning: do not rule out shortwave radiation just yet

Science.gov (United States)

Sedlar, J.

2017-12-01

Springtime atmospheric preconditioning of Arctic sea ice for enhanced or buffered sea ice melt during the subsequent melt year has received considerable research focus in recent years. A general consensus points to enhanced poleward atmospheric transport of moisture and heat during spring, effectively increasing the emission of longwave radiation to the surface. Studies have essentially ruled out the role of shortwave radiation as an effective preconditioning mechanism because of the relatively weak incident solar radiation and high surface albedo from sea ice and snow during spring. These conclusions, however, are derived primarily from atmospheric reanalysis data, which may not always represent an accurate depiction of the Arctic climate system. Here, observations of top of atmosphere radiation from state of the art satellite sensors are examined and compared with reanalysis and climate model data to examine the differences in the spring radiative budget over the Arctic Ocean for years with extreme low/high ice extent at the end of the ice melt season (September). Distinct biases are observed between satellite-based measurements and reanalysis/models, particularly for the amount of shortwave radiation trapped (warming effect) within the Arctic climate system during spring months. A connection between the differences in reanalysis/model surface albedo representation and the albedo observed by satellite is discussed. These results suggest that shortwave radiation should not be overlooked as a significant contributing mechanism to springtime Arctic atmospheric preconditioning.

Design of a temperature control system using incremental PID algorithm for a special homemade shortwave infrared spatial remote sensor based on FPGA

Science.gov (United States)

Xu, Zhipeng; Wei, Jun; Li, Jianwei; Zhou, Qianting

2010-11-01

An image spectrometer of a spatial remote sensing satellite requires shortwave band range from 2.1μm to 3μm which is one of the most important bands in remote sensing. We designed an infrared sub-system of the image spectrometer using a homemade 640x1 InGaAs shortwave infrared sensor working on FPA system which requires high uniformity and low level of dark current. The working temperature should be -15+/-0.2 Degree Celsius. This paper studies the model of noise for focal plane array (FPA) system, investigated the relationship with temperature and dark current noise, and adopts Incremental PID algorithm to generate PWM wave in order to control the temperature of the sensor. There are four modules compose of the FPGA module design. All of the modules are coded by VHDL and implemented in FPGA device APA300. Experiment shows the intelligent temperature control system succeeds in controlling the temperature of the sensor.

Mutagenesis and reparation processes in the methylotrophic bacterium Pseudomonas methanolica after UV irradiation

International Nuclear Information System (INIS)

Naumov, G.N.; Bokhan, I.K.; Multykh, I.G.

1986-01-01

High resistance of cells of methylotrophic bacterium Pseudomonas methanolica to bactericidal and mutagenous effects of ultraviolet irradiation is shown as well as activity of reparation processes after UV irradiation. The presence of low photoreactivating activity in P. methanolica is shown as well. Observed recovery in innutritious medium and decrease of irradiated cells survival rates under effect of reparation inhibitors (coffeine and acriflavine) testify to activity of excision reparation and, perhaps, recombination branch of postreplicative reparation. No manifestation of inducible reparation system is discovered. It is concluded that increased resistance of P. methanolica cells to bactericidal and mutagenous effects of short-wave ultraviolet radiation is related to activity of exact reparation systems

Effect of cold work on tensile behavior of irradiated type 316 stainless steel

International Nuclear Information System (INIS)

Klueh, R.L.; Maziasz, P.J.

1986-01-01

Tensile specimens were irradiated in ORR at 250, 290, 450, and 500 0 C to produce a displacement damage of approx.5 dpa and 40 at. ppM He. Irradiation at 250 and 290 0 C caused an increase in yield stress and ultimate tensile strength and a decrease in ductility relative to unaged and thermally aged controls. The changes were greatest for the 20%-cold-worked steel and lowest for the 50%-cold-worked steel. Irradiation at 450 0 C caused a slight relative decrease in strength for all cold-worked conditions. A large decrease was observed at 500 0 C, with the largest decrease occurring for the 50%-cold-worked specimen. No bubble, void, or precipitate formation was observed for specimens examined by transmission electron microscopy (TEM). The irradiation hardening was correlated with Frank-loop and ''black-dot'' loop damage. A strength decrease at 500 0 C was correlated with dislocation network recovery. Comparison of tensile and TEM results from ORR-irradiated steel with those from steels irradiated in the High Flux Isotope Reactor and the Experimental Breeder Reactor indicated consistent strength and microstructure changes

Void formation in cold-worked type 316 stainless steel irradiated with 1-MeV protons

International Nuclear Information System (INIS)

Keefer, D.W.; Pard, A.G.

1974-01-01

Cold-worked Type 316 stainless steel was irradiated at 500 and 600 0 C with 1-MeV protons. The dependence of void formation on displacement damage, irradiation temperature, and microstructure was studied by transmission electron microscopy. Cold working delays the onset of swelling and reduces it, via a reduction in void size, at both irradiation temperatures. Inhomogeneity in the cold-worked microstructure leads to inhomogeneity in the disposition of voids. Swelling at 600 is greater than at 500 0 C; the voids are less numerous but larger at the higher temperature. No change in the cold-worked microstructure can be detected by transmission electron microscopy after 500 0 C irradiation to 23 displacements per atom. Irradiation to a comparable damage level at 600 0 C results in almost complete elimination of the cold-worked microstructure. Comparison of the results is made with data from reactor irradiation experiments

TAO/TRITON, RAMA, and PIRATA Buoys, Daily, 1991-present, Downgoing Shortwave Radiation

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has daily Downgoing Shortwave Radiation data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

TAO/TRITON, RAMA, and PIRATA Buoys, Monthly, 1991-present, Net Shortwave Radiation

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has monthly Net Shortwave Radiation data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

Sensitivity of MENA Tropical Rainbelt to Dust Shortwave Absorption: A High Resolution AGCM Experiment

KAUST Repository

Bangalath, Hamza Kunhu; Stenchikov, Georgiy L.

2016-01-01

Shortwave absorption is one of the most important, but the most uncertain, components of direct radiative effect by mineral dust. It has a broad range of estimates from different observational and modeling studies and there is no consensus on the strength of absorption. To elucidate the sensitivity of the Middle East and North Africa (MENA) tropical summer rainbelt to a plausible range of uncertainty in dust shortwave absorption, AMIP-style global high resolution (25 km) simulations are conducted with and without dust, using the High-Resolution Atmospheric Model (HiRAM). Simulations with dust comprise three different cases by assuming dust as a very efficient, standard and inefficient absorber. Inter-comparison of these simulations shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. The maximum response and sensitivity are predicted over the northern edge of the rainbelt, geographically over Sahel. The sensitivity of the responses over the Sahel, especially that of precipitation, is comparable to the mean state. Locally, the response in precipitation reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. Taking into account that Sahel has a very high climate variability and is extremely vulnerable to changes in precipitation, the present study suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the Sahel climate.

Sensitivity of MENA Tropical Rainbelt to Dust Shortwave Absorption: A High Resolution AGCM Experiment

KAUST Repository

Bangalath, Hamza Kunhu

2016-06-13

Shortwave absorption is one of the most important, but the most uncertain, components of direct radiative effect by mineral dust. It has a broad range of estimates from different observational and modeling studies and there is no consensus on the strength of absorption. To elucidate the sensitivity of the Middle East and North Africa (MENA) tropical summer rainbelt to a plausible range of uncertainty in dust shortwave absorption, AMIP-style global high resolution (25 km) simulations are conducted with and without dust, using the High-Resolution Atmospheric Model (HiRAM). Simulations with dust comprise three different cases by assuming dust as a very efficient, standard and inefficient absorber. Inter-comparison of these simulations shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. The maximum response and sensitivity are predicted over the northern edge of the rainbelt, geographically over Sahel. The sensitivity of the responses over the Sahel, especially that of precipitation, is comparable to the mean state. Locally, the response in precipitation reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. Taking into account that Sahel has a very high climate variability and is extremely vulnerable to changes in precipitation, the present study suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the Sahel climate.

Work hardening characteristics of gamma-ray irradiated Al-5356 alloy

International Nuclear Information System (INIS)

Saad, G.; Fayek, S.A.; Fawzy, A.; Soliman, H.N.; Nassr, E.

2014-01-01

Effects of γ-irradiation and deformation temperatures on the hardening behavior of Al-5356 alloy have been investigated by means of stress–strain measurements. Wire samples irradiated with different doses (ranging from 500 to 2000 kGy) were strained at different deformation temperatures T w (ranging from 303 to 523 K) and a constant strain rate of 1.5×10 −3 s −1 . The effect of γ-irradiation on the work-hardening parameters (WHP): yield stress σ y , fracture stress σ f , total strain ε T and work-hardening coefficient χ p of the given alloy was studied at the applied deformation temperature range. The obtained results showed that γ-irradiation exhibited an increase in the WHP of the given alloy while the increase in its deformation temperature showed a reverse effect. The mean activation energy of the deformation process was calculated using an Arrhenius-type relation, and was found to be ∼80 kJ/mole, which is close to that of grain boundary diffusion in aluminum alloys

Some observations on stray magnetic fields and power outputs from short-wave diathermy equipment

Energy Technology Data Exchange (ETDEWEB)

Lau, R.W.M.; Dunscombe, P.B.

1984-04-01

Recent years have seen increasing interest in the possible hazards arising from the use of nonionizing electromagnetic radiation. Relatively large and potentially hazardous fields are to be found in the vicinity of short-wave and microwave equipment used in physiotherapy departments to produce therapeutic temperature rises. This note reports the results of measurements of the stray magnetic field and power output of a conventional short-wave diathermy unit when applied to tissue-equivalent phantoms. The dependence of these quantities on the variables, i.e. power setting of the unit, capacitor plate size, phantom size and phantom-capacitor plate separation, are discussed.

Leaf temperature and transpiration of rice plants in relation to short-wave radiation and wind speed

International Nuclear Information System (INIS)

Ito, D.; Haseba, T.

1984-01-01

Leaf temperature and transpiration amount of rice plants were measured in a steady environment in a laboratory and in field situations. The plants set in Wagner pots were used. Experiments were carried out at the tillering and booting stages, and on the date of maturity. Measured leaf temperatures and transpiration rates were analyzed in connection with incident short-wave radiation on a leaf and wind speed measured simultaneously.Instantaneous supplying and turning-off of steady artificial light caused cyclic changes in leaf temperature and transpiration. Leaf temperature dropped in feeble illumination compared with the steady temperature in the preceeding dark.On the date of maturity, a rice plant leaf was warmer than the air, even in feeble light. Then, the leaf-air temperature difference and transpiration rate showed approximately linear increases with short-wave radiation intensity. On the same date, an increase in wind speed produced a decrease in leaf-air temperature difference, i.e., leaf temperature dropped, and an increase in transpiration rate. The rates of both changes in leaf temperature and transpiration rate were fairly large in a range of wind speed below about 1m/s.For rice plants growing favorably from the tillering stage through the booting stage, the leaves were considerably cooler than the air, even in an intense light and/or solar radiation. The leaf temperature showed the lowest value at short-wave radiations between 0.15 and 0.20ly/min, at above which the leaf temperature rised with an increase in short-wave radiation until it approached the air temperature. Transpiration rate of rice plants increased rapidly with an increase in short-wave radiation ranging below 0.2 or 0.3ly/min, at above which the increase in transpiration rate slowed.The relationships between leaf temperature and/or transpiration rate and wind speed and/or incident short-wave radiation (solar radiation) which were obtained experimentally, supported the relationships

Short-wave albedo of a pine forest

Energy Technology Data Exchange (ETDEWEB)

Kessler, A.

1985-06-01

In this paper nine years of continuous records of the short-wave albedo above a Scotch pine forest in middle Europe were analysed. Special emphasis was given to the dependencies of the albedo on its diurnal variation, its annual variation, the solar altitude, the structure of the stand, the cloud cover, the soil moisture and the spectral reflectance. A long-termed trend of the albedo could not be found, e.g. caused by the stand growth. Finally the annual variation of the albedo of the Scotch pine forest was compared with measurements above different surface types in middle Europe.

A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-Cloud Aerosols Using CALIOP and MODIS Data

Science.gov (United States)

Zhang, Z.; Meyer, K.; Platnick, S.; Oreopoulos, L.; Lee, D.; Yu, H.

2014-01-01

This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.

Net Surface Shortwave Radiation from GOES Imagery—Product Evaluation Using Ground-Based Measurements from SURFRAD

Directory of Open Access Journals (Sweden)

Anand K. Inamdar

2015-08-01

Full Text Available The Earth’s surface net radiation controls the energy and water exchanges between the Earth’s surface and the atmosphere, and can be derived from satellite observations. The ability to monitor the net surface radiation over large areas at high spatial and temporal resolution is essential for many applications, such as weather forecasting, short-term climate prediction or water resources management. The objective of this paper is to derive the net surface radiation in the shortwave domain at high temporal (half-hourly and spatial resolution (~1 km using visible imagery from Geostationary Operational Environmental Satellite (GOES. The retrieval algorithm represents an adaptation to GOES data of a standard algorithm initially developed for the NASA-operated Clouds and Earth’s Radiant Energy System (CERES scanner. The methodology relies on: (1 the estimation of top of atmosphere shortwave radiation from GOES spectral measurements; and (2 the calculation of net surface shortwave (SW radiation accounting for atmospheric effects. Comparison of GOES-retrieved net surface shortwave radiation with ground-measurements at the National Oceanic and Atmospheric Administration’s (NOAA Surface Radiation (SURFRAD stations yields very good agreement with average bias lower than 5 W·m−2 and root mean square difference around 70 W·m−2. The algorithm performance is usually higher over areas characterized by low spatial variability in term of land cover type and surface biophysical properties. The technique does not involve retrieval and assessment of cloud properties and can be easily adapted to other meteorological satellites around the globe.

Top-down and bottom-up aerosol-cloud closure: towards understanding sources of uncertainty in deriving cloud shortwave radiative flux

Science.gov (United States)

Sanchez, Kevin J.; Roberts, Gregory C.; Calmer, Radiance; Nicoll, Keri; Hashimshoni, Eyal; Rosenfeld, Daniel; Ovadnevaite, Jurgita; Preissler, Jana; Ceburnis, Darius; O'Dowd, Colin; Russell, Lynn M.

2017-08-01

Top-down and bottom-up aerosol-cloud shortwave radiative flux closures were conducted at the Mace Head Atmospheric Research Station in Galway, Ireland, in August 2015. This study is part of the BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding) European collaborative project, with the goal of understanding key processes affecting aerosol-cloud shortwave radiative flux closures to improve future climate predictions and develop sustainable policies for Europe. Instrument platforms include ground-based unmanned aerial vehicles (UAVs)1 and satellite measurements of aerosols, clouds and meteorological variables. The ground-based and airborne measurements of aerosol size distributions and cloud condensation nuclei (CCN) concentration were used to initiate a 1-D microphysical aerosol-cloud parcel model (ACPM). UAVs were equipped for a specific science mission, with an optical particle counter for aerosol distribution profiles, a cloud sensor to measure cloud extinction or a five-hole probe for 3-D wind vectors. UAV cloud measurements are rare and have only become possible in recent years through the miniaturization of instrumentation. These are the first UAV measurements at Mace Head. ACPM simulations are compared to in situ cloud extinction measurements from UAVs to quantify closure in terms of cloud shortwave radiative flux. Two out of seven cases exhibit sub-adiabatic vertical temperature profiles within the cloud, which suggests that entrainment processes affect cloud microphysical properties and lead to an overestimate of simulated cloud shortwave radiative flux. Including an entrainment parameterization and explicitly calculating the entrainment fraction in the ACPM simulations both improved cloud-top radiative closure. Entrainment reduced the difference between simulated and observation-derived cloud-top shortwave radiative flux (δRF) by between 25 and 60 W m-2. After accounting for entrainment

In vitro assessment of cardiac performance after irradiation using an isolated working rat heart preparation

International Nuclear Information System (INIS)

Wondergem, J.; Laarse, A. van der; Ravels, F.J.M. van; Wermeskerken, A.-M. van; Verhoeve, H.R.; Graaf, B.W. de; Leer, J.W.H.

1991-01-01

The effect of irradiation on cardiac function was assessed using an isolated working rat heart preparation. The animals were given single doses of X-rays in the range 15-30 Gy to their hearts. Cardiac output (CO = aortic flow + coronary flow), heart weight and body weight were followed for a period of 10 months after treatment. Irradiation led to a decrease in cardiac function. This reduction was dose-dependent and progressive with time after treatment. The shape of the Frank-Starling curves constructed for irradiated hearts suggests a loss of contractile function of the myocardium. Coronary flow rates measured in 'working' hearts and in 'Langendorff' hearts were not significantly changed by the irradiation treatment. The isolated working rat heart preparation proved to be a simple and suitable animal model for the investigation of irradiation-induced cardiotoxicity. (author)

Sensitivity of tropical rainbelt over Africa and Middle East to dust shortwave absorption: Experiments using a high resolution AGCM

KAUST Repository

Bangalath, Hamza Kunhu; Stenchikov, Georgiy L.

2015-01-01

Response of the rainbelt over Africa to dust direct radiative forcing has been an area of lively debate and is a subject of ongoing research. Previous modeling studies have contrasting results producing different amplitudes or even signs of responses. Uncertainties in the dust radiative forcing are thought to be the major cause of discrepancies in the simulated responses among various studies. The imaginary part of mineral dust shortwave refractive index, which defines the dust absorptivity, has a wide range of values estimated from various observational and modeling studies, as it depends on dust chemical composition and mineralogy. Balkanski et al. (2007) estimated dust shortwave refractive indices by assuming 3 different hematite contents, 0.9%, 1.5% and 2.7% by volume, which corresponds to inefficient, standard, and very efficient dust shortwave absorption, respectively. To investigate the sensitivity of the position and intensity of the tropical rainbelt over Africa and its extension to the Arabian Peninsula to dust shortwave absorption, we have conducted ensembles of numerical simulations for each of the three dust absorptivity scenarios using a high resolution Atmospheric General Circulation Model (AGCM), GFDL's High Resolution Atmospheric Model (HiRAM), at a spatial resolution of 25 km. We found that the strength and the latitudinal extent of the rainbelt are very sensitive to dust shortwave absorption, as well as circulations at various spatiotemporal scales that drive the climate of the region. Reference: Balkanski, Y., M. Schulz, T. Claquin, and S. Guibert (2007), Reevaluation of mineral aerosol radiative forcings suggests a better agreement with satellite and AERONET data, Atmos. Chem. Phys., 7, 81 - 95.

Estimating net short-wave radiation with the Bellani pyranometer

International Nuclear Information System (INIS)

Bernier, Y.; Plamondon, A.P.

1983-01-01

Two methods were developed by which daily net short-wave radiation (K∗) can be evaluated from Bellani pyranometer readings. The first method involves a simple regression equation. The second method uses a physical approach taking into account the effect of the Bellani's geometry on its response to direct and diffuse radiation throughout the day. Both methods, when tested on experimental data, tended to underestimate the measured K∗, the regression approach exhibiting a higher variance of the error [fr

Sensitivity of tropical rainbelt over Africa and Middle East to dust shortwave absorption: Experiments using a high resolution AGCM

KAUST Repository

Bangalath, Hamza Kunhu

2015-04-01

Response of the rainbelt over Africa to dust direct radiative forcing has been an area of lively debate and is a subject of ongoing research. Previous modeling studies have contrasting results producing different amplitudes or even signs of responses. Uncertainties in the dust radiative forcing are thought to be the major cause of discrepancies in the simulated responses among various studies. The imaginary part of mineral dust shortwave refractive index, which defines the dust absorptivity, has a wide range of values estimated from various observational and modeling studies, as it depends on dust chemical composition and mineralogy. Balkanski et al. (2007) estimated dust shortwave refractive indices by assuming 3 different hematite contents, 0.9%, 1.5% and 2.7% by volume, which corresponds to inefficient, standard, and very efficient dust shortwave absorption, respectively. To investigate the sensitivity of the position and intensity of the tropical rainbelt over Africa and its extension to the Arabian Peninsula to dust shortwave absorption, we have conducted ensembles of numerical simulations for each of the three dust absorptivity scenarios using a high resolution Atmospheric General Circulation Model (AGCM), GFDL\\'s High Resolution Atmospheric Model (HiRAM), at a spatial resolution of 25 km. We found that the strength and the latitudinal extent of the rainbelt are very sensitive to dust shortwave absorption, as well as circulations at various spatiotemporal scales that drive the climate of the region. Reference: Balkanski, Y., M. Schulz, T. Claquin, and S. Guibert (2007), Reevaluation of mineral aerosol radiative forcings suggests a better agreement with satellite and AERONET data, Atmos. Chem. Phys., 7, 81 - 95.

Swelling in cold-worked 316 stainless steels irradiated in a PWR

Energy Technology Data Exchange (ETDEWEB)

Fukuya, Koji; Fujii, Katsuhiko [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2001-09-01

Swelling behavior in a cold-worked 316 stainless steel irradiated up to 53 dpa in a PWR at 290-320degC was examined using high resolution transmission electron microscopy. Small cavities with the average diameter of 1 nm were observed in the samples irradiated to doses above 3 dpa. The average diameter did not increase with increasing in dose. The maximum swelling was as low as 0.042%. The measured helium content and the cavity morphology led to the conclusion that the cavities were helium bubbles. A comparison of the observed cavity microstructure with data from FBR, HFIR and ATR irradiation showed that the cavity structure in PWR at 320degC or less was similar to those in HFIR and ATR irradiation but quite different from those in FBR condition. From a calculation based on the cavity data and kinetic models the incubation dose of swelling was estimated to be higher than 80dpa in the present irradiation condition. (author)

A Novel Method for Estimating Shortwave Direct Radiative Effect of Above-cloud Aerosols over Ocean Using CALIOP and MODIS Data

Science.gov (United States)

Zhang, Z.; Meyer, K.; Platnick, S.; Oreopoulos, L.; Lee, D.; Yu, H.

2013-01-01

This paper describes an efficient and unique method for computing the shortwave direct radiative effect (DRE) of aerosol residing above low-level liquid-phase clouds using CALIOP and MODIS data. It accounts for the overlapping of aerosol and cloud rigorously by utilizing the joint histogram of cloud optical depth and cloud top pressure. Effects of sub-grid scale cloud and aerosol variations on DRE are accounted for. It is computationally efficient through using grid-level cloud and aerosol statistics, instead of pixel-level products, and a pre-computed look-up table in radiative transfer calculations. We verified that for smoke over the southeast Atlantic Ocean the method yields a seasonal mean instantaneous shortwave DRE that generally agrees with more rigorous pixel-level computation within 4%. We have also computed the annual mean instantaneous shortwave DRE of light-absorbing aerosols (i.e., smoke and polluted dust) over global ocean based on 4 yr of CALIOP and MODIS data. We found that the variability of the annual mean shortwave DRE of above-cloud light-absorbing aerosol is mainly driven by the optical depth of the underlying clouds.

Characterizing the information content of cloud thermodynamic phase retrievals from the notional PACE OCI shortwave reflectance measurements

Science.gov (United States)

Coddington, O. M.; Vukicevic, T.; Schmidt, K. S.; Platnick, S.

2017-08-01

We rigorously quantify the probability of liquid or ice thermodynamic phase using only shortwave spectral channels specific to the National Aeronautics and Space Administration's Moderate Resolution Imaging Spectroradiometer, Visible Infrared Imaging Radiometer Suite, and the notional future Plankton, Aerosol, Cloud, ocean Ecosystem imager. The results show that two shortwave-infrared channels (2135 and 2250 nm) provide more information on cloud thermodynamic phase than either channel alone; in one case, the probability of ice phase retrieval increases from 65 to 82% by combining 2135 and 2250 nm channels. The analysis is performed with a nonlinear statistical estimation approach, the GEneralized Nonlinear Retrieval Analysis (GENRA). The GENRA technique has previously been used to quantify the retrieval of cloud optical properties from passive shortwave observations, for an assumed thermodynamic phase. Here we present the methodology needed to extend the utility of GENRA to a binary thermodynamic phase space (i.e., liquid or ice). We apply formal information content metrics to quantify our results; two of these (mutual and conditional information) have not previously been used in the field of cloud studies.

Top-down and bottom-up aerosol–cloud closure: towards understanding sources of uncertainty in deriving cloud shortwave radiative flux

Directory of Open Access Journals (Sweden)

K. J. Sanchez

2017-08-01

Full Text Available Top-down and bottom-up aerosol–cloud shortwave radiative flux closures were conducted at the Mace Head Atmospheric Research Station in Galway, Ireland, in August 2015. This study is part of the BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding European collaborative project, with the goal of understanding key processes affecting aerosol–cloud shortwave radiative flux closures to improve future climate predictions and develop sustainable policies for Europe. Instrument platforms include ground-based unmanned aerial vehicles (UAVs1 and satellite measurements of aerosols, clouds and meteorological variables. The ground-based and airborne measurements of aerosol size distributions and cloud condensation nuclei (CCN concentration were used to initiate a 1-D microphysical aerosol–cloud parcel model (ACPM. UAVs were equipped for a specific science mission, with an optical particle counter for aerosol distribution profiles, a cloud sensor to measure cloud extinction or a five-hole probe for 3-D wind vectors. UAV cloud measurements are rare and have only become possible in recent years through the miniaturization of instrumentation. These are the first UAV measurements at Mace Head. ACPM simulations are compared to in situ cloud extinction measurements from UAVs to quantify closure in terms of cloud shortwave radiative flux. Two out of seven cases exhibit sub-adiabatic vertical temperature profiles within the cloud, which suggests that entrainment processes affect cloud microphysical properties and lead to an overestimate of simulated cloud shortwave radiative flux. Including an entrainment parameterization and explicitly calculating the entrainment fraction in the ACPM simulations both improved cloud-top radiative closure. Entrainment reduced the difference between simulated and observation-derived cloud-top shortwave radiative flux (δRF by between 25 and 60 W m−2. After

Enhanced solar global irradiance during cloudy sky conditions

Energy Technology Data Exchange (ETDEWEB)

Schade, N.H.; Sandmann, H.; Stick, C. [Kiel Univ. (Germany). Inst. fuer Medizinische Klimatologie; Macke, A. [Kiel Univ. (DE). Leibniz Inst. fuer Meereswissenschaften (IFM-GEOMAR)

2007-06-15

The impact of cloudiness on the shortwave downwelling radiation (SDR) at the surface is investigated by means of collocated pyranometer radiation measurements and all-sky imager observations. The measurements have been performed in Westerland, a seaside resort on the North Sea island of Sylt, Germany, during summer 2004 and 2005. A main improvement to previous studies on this subject resulted from the very high temporal resolution of cloud images and radiation measurements and, therefore, a more robust statistical analysis of the occurrence of this effect. It was possible to observe an excess of solar irradiation compared to clear sky irradiation by more than 500 W/m{sup 2}, the largest observed excess irradiation to our knowledge so far. Camera images reveal that largest excess radiation is reached close to overcast situations with altocumulus clouds partly obscuring the solar disk, and preferably with cumulus clouds in lower levels. The maximum duration of the enhancements depends on its strength and ranges from 20 seconds (enhancements > 400 W/m{sup 2}) up to 140 seconds (enhancements > 200 W/m{sup 2}). (orig.)

Background estimation in short-wave region during determination of total sample composition by x-ray fluorescence method

International Nuclear Information System (INIS)

Simakov, V.A.; Kordyukov, S.V.; Petrov, E.N.

1988-01-01

Method of background estimation in short-wave spectral region during determination of total sample composition by X-ray fluorescence method is described. 13 types of different rocks with considerable variations of base composition and Zr, Nb, Th, U content below 7x10 -3 % are investigated. The suggested method of background accounting provides for a less statistical error of the background estimation than direct isolated measurement and reliability of its determination in a short-wave region independent on the sample base. Possibilities of suggested method for artificial mixtures conforming by the content of main component to technological concemtrates - niobium, zirconium, tantalum are estimated

Gamma-Weighted Discrete Ordinate Two-Stream Approximation for Computation of Domain Averaged Solar Irradiance

Science.gov (United States)

Kato, S.; Smith, G. L.; Barker, H. W.

2001-01-01

An algorithm is developed for the gamma-weighted discrete ordinate two-stream approximation that computes profiles of domain-averaged shortwave irradiances for horizontally inhomogeneous cloudy atmospheres. The algorithm assumes that frequency distributions of cloud optical depth at unresolved scales can be represented by a gamma distribution though it neglects net horizontal transport of radiation. This algorithm is an alternative to the one used in earlier studies that adopted the adding method. At present, only overcast cloudy layers are permitted.

Simulation of tensile stress-strain properties of irradiated type 316 SS by heavily cold-worked material

International Nuclear Information System (INIS)

Muto, Yasushi; Jitsukawa, Shiro; Hishinuma, Akimichi

1995-07-01

Type 316 stainless steel is one of the most promising candidate materials to be used for the structural parts of plasma facing components in the nuclear fusion reactor. The neutron irradiation make the material brittle and reduces its uniform elongation to almost zero at heavy doses. In order to apply such a material of reduced ductility to structural components, the structural integrity should be examined and assured by the fracture mechanics. The procedure requires a formulated stress-strain relationship. However, the available irradiated tensile test data are very limited at present, so that the cold-worked material was used as a simulated material in this study. Property changes of 316 SS, that is, a reduction of uniform elongation and an enhancement of yield stress are seemingly very similar for both the irradiated 316 SS and the cold-worked one. The specimens made of annealed 316 SS, 20% (or 15%) cold worked one and 40% cold worked one were prepared. After the formulation of stress strain behavior, the equation for the cold-worked 316 SS was fitted to the data on irradiated material under the assumption that the yield stress is the same for both materials. In addition, the upper limit for the plastic strain was introduced using the data on the irradiated material. (author)

Single interval shortwave radiation scheme with parameterized optical saturation and spectral overlaps

Czech Academy of Sciences Publication Activity Database

Mašek, Jan; Geleyn, J.- F.; Brožková, Radmila; Giot, O.; Achom, H. O.; Kuma, P.

2016-01-01

Roč. 142, č. 659 (2016), s. 304-326 ISSN 0035-9009 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : shortwave radiative transfer * delta-two stream system * broadband approach * Malkmus band model * optical saturation * idealized optical paths * spectral overlap Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.444, year: 2016

The work of the 'Irradiation Damage' sub-group of the EURATOM Working Group on Research Reactor Dosimetry

International Nuclear Information System (INIS)

Genthon, J.P.

1975-01-01

The EURATOM Working Group on Reactor Dosimetry is investigating the problems of the dosimetry of radiation damage experiments. Papers have been published on the dosimetry of graphite and irradiation of metals: the model chosen, the quantities employed to express the fluences, numerical values, measurements, and measurement techniques. The ensuing work of the EURATOM Working Group of Reactor Dosimetry in these areas will deal with the measurement methods required for the dosimetry of radiation damage. (Auth.)

Sub-grid-scale effects on short-wave instability in magnetized hall-MHD plasma

International Nuclear Information System (INIS)

Miura, H.; Nakajima, N.

2010-11-01

Aiming to clarify effects of short-wave modes on nonlinear evolution/saturation of the ballooning instability in the Large Helical Device, fully three-dimensional simulations of the single-fluid MHD and the Hall MHD equations are carried out. A moderate parallel heat conductivity plays an important role both in the two kinds of simulations. In the single-fluid MHD simulations, the parallel heat conduction effectively suppresses short-wave ballooning modes but it turns out that the suppression is insufficient in comparison to an experimental result. In the Hall MHD simulations, the parallel heat conduction triggers a rapid growth of the parallel flow and enhance nonlinear couplings. A comparison between single-fluid and the Hall MHD simulations reveals that the Hall MHD model does not necessarily improve the saturated pressure profile, and that we may need a further extension of the model. We also find by a comparison between two Hall MHD simulations with different numerical resolutions that sub-grid-scales of the Hall term should be modeled to mimic an inverse energy transfer in the wave number space. (author)

Two pathogen reduction technologies--methylene blue plus light and shortwave ultraviolet light--effectively inactivate hepatitis C virus in blood products.

Science.gov (United States)

Steinmann, Eike; Gravemann, Ute; Friesland, Martina; Doerrbecker, Juliane; Müller, Thomas H; Pietschmann, Thomas; Seltsam, Axel

2013-05-01

Contamination of blood products with hepatitis C virus (HCV) can cause infections resulting in acute and chronic liver diseases. Pathogen reduction methods such as photodynamic treatment with methylene blue (MB) plus visible light as well as irradiation with shortwave ultraviolet (UVC) light were developed to inactivate viruses and other pathogens in plasma and platelet concentrates (PCs), respectively. So far, their inactivation capacities for HCV have only been tested in inactivation studies using model viruses for HCV. Recently, a HCV infection system for the propagation of infectious HCV in cell culture was developed. Inactivation studies were performed with cell culture-derived HCV and bovine viral diarrhea virus (BVDV), a model for HCV. Plasma units or PCs were spiked with high titers of cell culture-grown viruses. After treatment of the blood units with MB plus light (Theraflex MB-Plasma system, MacoPharma) or UVC (Theraflex UV-Platelets system, MacoPharma), residual viral infectivity was assessed using sensitive cell culture systems. HCV was sensitive to inactivation by both pathogen reduction procedures. HCV in plasma was efficiently inactivated by MB plus light below the detection limit already by 1/12 of the full light dose. HCV in PCs was inactivated by UVC irradiation with a reduction factor of more than 5 log. BVDV was less sensitive to the two pathogen reduction methods. Functional assays with human HCV offer an efficient tool to directly assess the inactivation capacity of pathogen reduction procedures. Pathogen reduction technologies such as MB plus light treatment and UVC irradiation have the potential to significantly reduce transfusion-transmitted HCV infections. © 2012 American Association of Blood Banks.

Report of the Working Group on low-temperature neutron irradiation

International Nuclear Information System (INIS)

1982-07-01

This report summarizes deliberations at a Working Group meeting sponsored by the Department of Energy, Division of Materials Sciences for the purpose of: (1) assessing the need for maintaining a low temperature neutron irradiation program in the United States; and (2) recommending a course of action based on this assessment

Irradiation damage in graphite. The works of Professor B.T. Kelly

International Nuclear Information System (INIS)

Marsden, B.J.

1996-01-01

The irradiation damage produced in graphite by energetic neutrons (>100eV) has been extensively studied because of the use of graphite as a moderator in thermal nuclear reactors. In recent times, graphite has been adopted as the protective tiling of the inner wall of experimental fusion systems and property changes due to fusion neutrons have become important. The late Professor B.T. Kelly reviewed the work carried out on the irradiation behaviour of graphite since the 1940s. This work is particularly timely as the scale of research into the effects of fission neutrons has been greatly reduced and many of the active researchers have retired. In recent years, new programmes of work are being formulated for the use of graphite in both the field of high temperature reactor systems and fusion systems. It is therefore important that the knowledge gained by Professor Kelly and other workers is not lost but passed on to future generations of nuclear scientists and engineers. This paper reviews Professor Kelly's last work, it also draws on the experience gained during many long discussions with Brian during the years he worked closely with the present graphite team at AEA Technology. It is hoped to publish his work in full in the near future. (author). 13 refs, 14 figs, 3 tabs

Resistivity recovery of neutron-irradiated and cold-worked thorium

International Nuclear Information System (INIS)

Tang, J.T.

1977-02-01

Results from a study of the resistivity recovery of neutron-irradiated and cold-worked thorium on isochronal annealing, activation energies, and isothermal annealing and kinetics are discussed. The nature and extent of radiation effects on the resistivity of thorium at 80 0 K, interpretation of stage II recovery above 80 0 K, and activation energy and interpretation of stage III recovery are also discussed. There are 79 references

Establishing BRDF calibration capabilities through shortwave infrared

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2017-09-01

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Distribution Functions (BRDFs) of the laboratory and flight diffusers used in their pre-flight and on-orbit calibrations. This paper advances that initial work and presents a comparison of spectral Bidirectional Reflectance Distribution Function (BRDF) and Directional Hemispherical Reflectance (DHR) of Spectralon*, a common material for laboratory and onorbit flight diffusers. A new measurement setup for BRDF measurements from 900 nm to 2500 nm located at NASA Goddard Space Flight Center (GSFC) is described. The GSFC setup employs an extended indium gallium arsenide detector, bandpass filters, and a supercontinuum light source. Comparisons of the GSFC BRDF measurements in the shortwave infrared (SWIR) with those made by the National Institute of Standards and Technology (NIST) Spectral Tri-function Automated Reference Reflectometer (STARR) are presented. The Spectralon sample used in this study was 2 inch diameter, 99% white pressed and sintered Polytetrafluoroethylene (PTFE) target. The NASA/NIST BRDF comparison measurements were made at an incident angle of 0° and viewing angle of 45° . Additional BRDF data not compared to NIST were measured at additional incident and viewing angle geometries and are not presented here. The total combined uncertainty for the measurement of BRDF in the SWIR range made by the GSFC scatterometer is less than 1% (k = 1). This study is in support of the calibration of the Radiation Budget Instrument (RBI) and Visible Infrared Imaging Radiometer Suit (VIIRS) instruments of the Joint Polar Satellite System (JPSS) and other current and future NASA remote sensing missions operating across the reflected solar wavelength region.

Survey of the spectral irradiance distribution of fluorescent tubes for solaria

International Nuclear Information System (INIS)

Johnsen, B.; Hannevik, M.

1993-01-01

The report describes a systematic mapping of the spectral irradiance distribution of typical fluorescent tubes, emitting ultraviolet radiation (UVR). The spectra were multiplied with biological action curves for assessing their potential for acute harmful effects. Comparing values of effective irradiance revealed a difference by a factor of ten between tubes for cosmetic UVR-treatment. Comparing spectra of the strongest cosmetic types with the spectrum of a typical tube for medical UVR-treatment revealed another factor of ten in effective irradiance. Spectra of typical cosmetic solarium tubes and natural sun at summer in Oslo are shown to be closely related in the UV-region, thereby justifying the term artificial sunlamps. Threshold limit values and action curves, as expressed in the former Norwegian solarium prescriptions from 1983 and the CENELEC standard for classifying UVR-emitting appliance, were compared. Calculations have shown that an adoption of the CENELEC threshold limit values will be more restrictive on the short-wave UV-region, while they generally will be similar, or a bit less restrictive on the longwave UV-region. 3 refs., 45 figs., 6 tabs

Chalcogen doping of silicon via intense femtosecond-laser irradiation

International Nuclear Information System (INIS)

Sheehy, Michael A.; Tull, Brian R.; Friend, Cynthia M.; Mazur, Eric

2007-01-01

We have previously shown that doping silicon with sulfur via femtosecond-laser irradiation leads to near-unity absorption of radiation from ultraviolet wavelengths to below band gap short-wave infrared wavelengths. Here, we demonstrate that doping silicon with two other group VI elements (chalcogens), selenium and tellurium, also leads to near-unity broadband absorption. A powder of the chalcogen dopant is spread on the silicon substrate and irradiated with femtosecond-laser pulses. We examine and compare the resulting morphology, optical properties, and chemical composition for each chalcogen-doped substrate before and after thermal annealing. Thermal annealing reduces the absorption of below band gap radiation by an amount that correlates with the diffusivity of the chalcogen dopant used to make the sample. We propose a mechanism for the absorption of below band gap radiation based on defects in the lattice brought about by the femtosecond-laser irradiation and the presence of a supersaturated concentration of chalcogen dopant atoms. The selenium and tellurium doped samples show particular promise for use in infrared photodetectors as they retain most of their infrared absorptance even after thermal annealing-a necessary step in many semiconductor device manufacturing processes

Short-wave infrared barriode detectors using InGaAsSb absorption material lattice matched to GaSb

Energy Technology Data Exchange (ETDEWEB)

Craig, A. P.; Percy, B.; Marshall, A. R. J. [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom); Jain, M. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Wicks, G.; Hossain, K. [Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); Golding, T. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); McEwan, K.; Howle, C. [Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ (United Kingdom)

2015-05-18

Short-wave infrared barriode detectors were grown by molecular beam epitaxy. An absorption layer composition of In{sub 0.28}Ga{sub 0.72}As{sub 0.25}Sb{sub 0.75} allowed for lattice matching to GaSb and cut-off wavelengths of 2.9 μm at 250 K and 3.0 μm at room temperature. Arrhenius plots of the dark current density showed diffusion limited dark currents approaching those expected for optimized HgCdTe-based detectors. Specific detectivity figures of around 7×10{sup 10} Jones and 1×10{sup 10} Jones were calculated, for 240 K and room temperature, respectively. Significantly, these devices could support focal plane arrays working at higher operating temperatures.

CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared

Science.gov (United States)

Guerin, François; Dantes, Didier; Savaria, Eric; Selingardi, Mario Luis; Montes, Amauri Silva

2018-04-01

This paper, "CIMEX: a prototype Instrument to observe from space the amazon forest In the near and shortwave infrared," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

Integrable discretizations for the short-wave model of the Camassa-Holm equation

International Nuclear Information System (INIS)

Feng Baofeng; Maruno, Ken-ichi; Ohta, Yasuhiro

2010-01-01

The link between the short-wave model of the Camassa-Holm equation (SCHE) and bilinear equations of the two-dimensional Toda lattice equation is clarified. The parametric form of the N-cuspon solution of the SCHE in Casorati determinant is then given. Based on the above finding, integrable semi-discrete and full-discrete analogues of the SCHE are constructed. The determinant solutions of both semi-discrete and fully discrete analogues of the SCHE are also presented.

Proceedings of 1991-workshops of the working group on 'Development and application of facilities for low temperature irradiation as well as controlled irradiation'

International Nuclear Information System (INIS)

Kuramoto, Eiichi; Okada, Moritami

1992-09-01

This is the proceedings of 1991-workshops of the working group on 'Development and Application of Facilities for Low Temperature Irradiation as well as Controlled Irradiation' held at the Research Reactor Institute of Kyoto University on July 25, 1991 and on February 28, 1992. In the present proceedings, it is emphasized that the study of radiation damages in various materials must be performed under carefully controlled irradiation conditions (irradiation temperature, neutron spectrum and so forth) during reactor irradiations. Especially, it is pointed out that a middle scale reactor such as KUR is suitable for the precise control of neutron spectra. Several remarkable results, which are made through experiments using the Low Temperature Irradiation Facility in KUR (KUR-LTL), are reported. Also, possible advanced research programs are discussed including the worldwide topics on the radiation damages in metals, semi-conductors and also insulators. Further, the present status of KUR-LTL is reported and the advanced plan of the facility is proposed. (author)

Analytic Approximations for Soliton Solutions of Short-Wave Models for Camassa-Holm and Degasperis-Procesi Equations

International Nuclear Information System (INIS)

Yang Pei; Li Zhibin; Chen Yong

2010-01-01

In this paper, the short-wave model equations are investigated, which are associated with the Camassa-Holm (CH) and Degasperis-Procesi (DP) shallow-water wave equations. Firstly, by means of the transformation of the independent variables and the travelling wave transformation, the partial differential equation is reduced to an ordinary differential equation. Secondly, the equation is solved by homotopy analysis method. Lastly, by the transformations back to the original independent variables, the solution of the original partial differential equation is obtained. The two types of solutions of the short-wave models are obtained in parametric form, one is one-cusp soliton for the CH equation while the other one is one-loop soliton for the DP equation. The approximate analytic solutions expressed by a series of exponential functions agree well with the exact solutions. It demonstrates the validity and great potential of homotopy analysis method for complicated nonlinear solitary wave problems. (general)

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

Energy Technology Data Exchange (ETDEWEB)

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)

Dependence of irradiation creep on temperature and atom displacements in 20% cold worked type 316 stainless steel

International Nuclear Information System (INIS)

Gilbert, E.R.

1976-04-01

Irradiation creep studies with pressurized tubes of 20 percent cold worked Type 316 stainless steel were conducted in EBR-2. Results showed that as atom displacements are extended above 5 dpa and temperatures are increased above 375 0 C, the irradiation induced creep rate increases with both increasing atom displacements and increasing temperature. The stress exponent for irradiation induced creep remained near unity. Irradiation-induced effective creep strains up to 1.8 percent were observed without specimen failure. 13 figures

[Bare Soil Moisture Inversion Model Based on Visible-Shortwave Infrared Reflectance].

Science.gov (United States)

Zheng, Xiao-po; Sun, Yue-jun; Qin, Qi-ming; Ren, Hua-zhong; Gao, Zhong-ling; Wu, Ling; Meng, Qing-ye; Wang, Jin-liang; Wang, Jian-hua

2015-08-01

Soil is the loose solum of land surface that can support plants. It consists of minerals, organics, atmosphere, moisture, microbes, et al. Among its complex compositions, soil moisture varies greatly. Therefore, the fast and accurate inversion of soil moisture by using remote sensing is very crucial. In order to reduce the influence of soil type on the retrieval of soil moisture, this paper proposed a normalized spectral slope and absorption index named NSSAI to estimate soil moisture. The modeling of the new index contains several key steps: Firstly, soil samples with different moisture level were artificially prepared, and soil reflectance spectra was consequently measured using spectroradiometer produced by ASD Company. Secondly, the moisture absorption spectral feature located at shortwave wavelengths and the spectral slope of visible wavelengths were calculated after analyzing the regular spectral feature change patterns of different soil at different moisture conditions. Then advantages of the two features at reducing soil types' effects was synthesized to build the NSSAI. Thirdly, a linear relationship between NSSAI and soil moisture was established. The result showed that NSSAI worked better (correlation coefficient is 0.93) than most of other traditional methods in soil moisture extraction. It can weaken the influences caused by soil types at different moisture levels and improve the bare soil moisture inversion accuracy.

Satellite observed impacts of wildfires on regional atmosphere composition and shortwave radiative forcing: multiple cases study

Science.gov (United States)

Fu, Y.; Li, R.; Huang, J.; Bergeron, Y.; Fu, Y.

2017-12-01

Emissions of aerosols and trace gases from wildfires and the direct shortwave radiative forcing were studied using multi-satellite/sensor observations from Aqua Moderate-Resolution Imaging Spectroradiometer (MODIS), Aqua Atmospheric Infrared Sounder (AIRS), Aura Ozone Monitoring Instrument (OMI), and Aqua Cloud's and the Earth's Radiant Energy System (CERES). The selected cases occurred in Northeast of China (NEC), Siberia of Russia, California of America have dominant fuel types of cropland, mixed forest and needleleaf forest, respectively. The Fire radiative power (FRP) based emission coefficients (Ce) of aerosol, NOx (NO2+NO), formaldehyde (HCHO), and carbon monoxide (CO) showed significant differences from case to case. 1) the FRP of the cropland case in NEC is strongest, however, the Ce of aerosol is the lowest (20.51 ± 2.55 g MJ-1). The highest Ce of aerosol is 71.34 ± 13.24 g MJ-1 in the needleleaf fire case in California. 2) For NOx, the highest Ce existed in the cropland case in NEC (2.76 ± 0.25 g MJ-1), which is more than three times of those in the forest fires in Siberia and California. 3) The Ce of CO is 70.21±10.97 and 88.38±46.16 g MJ-1 in the forest fires in Western Siberia and California, which are about four times of that in cropland fire. 4) The variation of Ce of HCHO are relatively small among cases. Strong spatial correlations are found among aerosol optical depth (AOD), NOx, HCHO, and CO. The ratios of NOx to AOD, HCHO, and CO in the cropland case in NEC show much higher values than those in other cases. Although huge differences of emissions and composition ratios exist among cases, the direct shortwave (SW) radiative forcing efficiency (SWARFE) of smoke at the top of the atmosphere (TOA) are in good agreement, with the shortwave radiative forcing efficiencies values of 20.09 to 22.93 per unit AOD. Results in this study reveal noteworthy variations of the FRP-based emissions coefficient and relative chemical composition in the smoke

The multispectral reflectance of shortwave radiation by agricultural crops in relation with their morphological and optical properties

NARCIS (Netherlands)

Bunnik, N.J.J.

1978-01-01

Relations between morphological properties of uniform canopies. optical properties of the leaves and reflection of shortwave radiation, in the visible light region and the near infrared, by crops are the subject of this thesis.

The aim of the study was a further investigation of

Stationary spectra of short-wave convective and magnetostatic fluctuations in a finite-pressure plasma and anomalous heat conductivity

International Nuclear Information System (INIS)

Vakulenko, M.O.

1992-01-01

Within the general renormalized statistical approach, the low-frequency short-wave stationary spectra of potential and magnetic perturbations in a finite-pressure plasma, are obtained. Anomalous heat conductivity considerably enhances due to non-linear interaction between magnetic excitations. 11 refs. (author)

Contrails and their impact on shortwave radiation and photovoltaic power production – a regional model study

Directory of Open Access Journals (Sweden)

S. Gruber

2018-05-01

Full Text Available A high-resolution regional-scale numerical model was extended by a parameterization that allows for both the generation and the life cycle of contrails and contrail cirrus to be calculated. The life cycle of contrails and contrail cirrus is described by a two-moment cloud microphysical scheme that was extended by a separate contrail ice class for a better representation of the high concentration of small ice crystals that occur in contrails. The basic input data set contains the spatially and temporally highly resolved flight trajectories over Central Europe derived from real-time data. The parameterization provides aircraft-dependent source terms for contrail ice mass and number. A case study was performed to investigate the influence of contrails and contrail cirrus on the shortwave radiative fluxes at the earth's surface. Accounting for contrails produced by aircraft enabled the model to simulate high clouds that were otherwise missing on this day. The effect of these extra clouds was to reduce the incoming shortwave radiation at the surface as well as the production of photovoltaic power by up to 10 %.

Does shortwave absorption by methane influence its effectiveness?

Science.gov (United States)

Modak, Angshuman; Bala, Govindasamy; Caldeira, Ken; Cao, Long

2018-01-01

In this study, using idealized step-forcing simulations, we examine the effective radiative forcing of CH4 relative to that of CO2 and compare the effects of CH4 and CO2 forcing on the climate system. A tenfold increase in CH4 concentration in the NCAR CAM5 climate model produces similar long term global mean surface warming ( 1.7 K) as a one-third increase in CO2 concentration. However, the radiative forcing estimated for CO2 using the prescribed-SST method is 81% that of CH4, indicating that the efficacy of CH4 forcing is 0.81. This estimate is nearly unchanged when the CO2 physiological effect is included in our simulations. Further, for the same long-term global mean surface warming, we simulate a smaller precipitation increase in the CH4 case compared to the CO2 case. This is because of the fast adjustment processes—precipitation reduction in the CH4 case is larger than that of the CO2 case. This is associated with a relatively more stable atmosphere and larger atmospheric radiative forcing in the CH4 case which occurs because of near-infrared absorption by CH4 in the upper troposphere and lower stratosphere. Within a month after an increase in CH4, this shortwave heating results in a temperature increase of 0.8 K in the lower stratosphere and upper troposphere. In contrast, within a month after a CO2 increase, longwave cooling results in a temperature decrease of 3 K in the stratosphere and a small change in the upper troposphere. These fast adjustments in the lower stratospheric and upper tropospheric temperature, along with the adjustments in clouds in the troposphere, influence the effective radiative forcing and the fast precipitation response. These differences in fast climate adjustments also produce differences in the climate states from which the slow response begins to evolve and hence they are likely associated with differing feedbacks. We also find that the tropics and subtropics are relatively warmer in the CH4 case for the same global mean

Irradiation creep and creep rupture of titanium-modified austenitic stainless steels and their dependence on cold work level

International Nuclear Information System (INIS)

Garner, F.A.; Hamilton, M.L.; Eiholzer, C.R.; Toloczko, M.B.; Kumar, A.S.

1991-11-01

A titanium-modified austenitic type stainless steel was tested at three cold work levels to determine its creep and creep rupture properties under both thermal aging and neutron irradiation conditions. Both the thermal and irradiation creep behavior exhibit a complex non-monotonic relationship with cold work level that reflects the competition between a number of stress-sensitive and temperature-dependent microstructural processes. Increasing the degree of cold work to 30% from the conventional 20% level was detrimental to its performance, especially for applications above 550 degrees c. The 20% cold work level is preferable to the 10% level, in terms of both in-reactor creep rupture response and initial strength

Bibliographic review of works accomplished about irradiated chicken, fish and fish products , spices and condiments

International Nuclear Information System (INIS)

Bernardes, B.; Dias Filho, M.

1983-07-01

Table of foods that can be irradiated and its respective nominal doses are shown. Bibliographic reviews of works performed about irradiated chicken, fish and fish products, spices and condiments are shown. The irradiation purpose in chicken were to increase the shelf-life and to eliminate the pathogenic microorganism in chicken stored below 10 0 C; in fish and fish products the purposes were to control the insect infestation in dry-fish during the storage and the sell exposure to reduce the macrobian charge in packed and non packed fish and in fish products. To reduce pathogenic microorganism in packing and unpacking fish; in spices and condiments to control the insect infestation, to reduce the microbial contamination. (L.M.J.)

Cloud effects on the SW radiation at the surface at a mid-latitude site in southwestern Europe

Science.gov (United States)

Salgueiro, Vanda; João Costa, Maria; Silva, Ana Maria; Lanconelli, Christian; Bortoli, Daniele

2017-04-01

This work presents a study of cloud radiative effects on shortwave (CRESW) radiation at the surface in Évora region (southwestern Europe) during 2015 and a case study is analyzed. CRESW (in Wm-2) is defined as the difference between the net shortwave irradiance (downward minus upward shortwave irradiance) in cloudy and clear sky conditions. This measure is usually used to translate changes in the SW radiation that reaches the surface due to changes in clouds (type and/or cover). The CRESW is obtained using measured SW irradiance recorded with a Kipp&Zonen CM 6B pyranometer (broadband 305 - 2800 nm) during the period from January to December 2015, and is related with the cloud liquid water path (LWP) and with cloud ice water path (IWP) showing the importance of the different type of clouds in attenuating the SW radiation at the surface. The cloud modification factor, also a measure of the cloud radiative effects (CMF; ratio between the measured SW irradiance under cloudy conditions and the estimated SW irradiance in clear-sky conditions) is related with the cloud optical thickness (COT; obtained from satellite data). This relation between CMF and COT is shown for different cloud fractions revealing an exponential decreasing of CMF as COT increases. Reductions in the SW radiation of the order of 80% (CMF = 0.2) as well enhancements in the SW radiation larger than 30% (CMF = 1.3) were found for small COT values and for different cloud fractions. A case study to analyse the enhancement events in a cloudy day was considered and the cloud properties, COT and LWP (from satellite and surface measurements), were related with the CRESW.

Stabilized platform for tethered balloon soundings of broadband long- and short-wave radiation

International Nuclear Information System (INIS)

Alzheimer, J.M.; Anderson, G.A.; Whiteman, C.D.

1993-01-01

Changes in the composition of trace gases in the earth's atmosphere have been reported by many observers, and a general concern has been expressed regarding possible changes to the earth's climate that may be caused by radiatively active gases introduced into the earth's atmosphere by man's activities. Radiatively active trace gases produce temperature changes in the earth's atmosphere through changes in radiative flux divergence. Our knowledge of and means of measuring radiative flux divergence is very limited. A few observations of vertical radiative flux divergences have been reported from aircraft from radiometersondes from towers and from large tethered balloons. These measurement techniques suffers from one or more drawbacks, including shallow sounding depths (towers), high cost (aircraft), complicated logistics (large tethered balloons), and limitation to nighttime hours (radiometersondes). Changes in radiative flux divergence caused by anthropogenic trace gases are expected to be quite small, and will be difficult to measure with existing broadband radiative flux instruments. The emphasis of present research in global climate change is thus being focused on improving radiative transfer algorithms in global climate models. The radiative parameterizations in these models are at an early stage of development and information is needed regarding their performance, especially in cloudy conditions. The impetus for the research reported in this paper is the need for a device that can supplement existing means of measuring vertical profiles of long- and short-wave irradiance and radiative flux divergence. We have designed a small tethered-balloon-based system that can make radiometric soundings through the atmospheric boundary layer. This paper discusses the concept, the design considerations, and the design and construction of this sounding system. The performance of the system will be tested in a series of balloon flights scheduled for the fall and winter of 1992

Uncertainty in regional and zonal monthly mean downward surface irradiances from Edition 4.0 CERES Energy Balanced and Filled (EBAF) data product

Science.gov (United States)

Kato, S.; Rutan, D. A.; Rose, F. G.; Loeb, N. G.

2017-12-01

The surface of the Earth receives solar radiation (shortwave) and emission from the atmosphere (longwave). At a global and annual mean approximately 12% of solar radiation incident on the surface is reflected and the rest is absorbed by the surface. The surface emits radiation proportional to the forth power of the temperature. Although the uncertainty in global and annual mean surface irradiances is estimated in earlier studies (Zhang et al. 1995, 2004; L'Ecuyer et al. 2008; Stephens et al. 2012; Kato et al. 2012), only a few studies estimated the uncertainty in computed surface irradiances at smaller spatial and temporal scales (Zhang et al. 1995, 2004; Kato et al. 2012). We use surface observations at 46 buoys and 36 land sites and newly released the Edition 4.0 Clouds and the Earth's Radiant Energy System (CERES) Energy Balanced and Filled (EBAF)-surface data product to estimate the uncertainty in regional and zonal monthly mean downward shortwave and longwave surface irradiances. The root-mean-square difference of monthly mean computed and observed irradiances is used for the regional uncertainty. The uncertainty is separated into bias and spatially random components. The random component decreases when irradiances are averaged over a larger area, nearly inversely proportional to the number of surface observation sites. The presentation provides the uncertainty in the regional and zonal monthly mean downward surface irradiances over ocean and land. ReferencesKato, S. and N.G.Loeb, D. A.Rutan, F. G. Rose, S. Sun-Mack,W.F.Miller, and Y. Chen, 2012. Surv. Geophys., 33, 395-412, doi:10.1007/s10712-012-9179-x. L'Ecuyer, T. S., N. B. Wood, T. Haladay, G. L. Stephens, and P. W. Stackhouse Jr., 2008, J. Geophys. Res., 113, D00A15, doi:10.1029/2008JD009951. Stephens, G. L. and Coauthors, 2012, Nat. Geosci., 5, 691-696, doi:10.1038/ngeo1580. Zhang, Y., W. B. Rossow, A. A. Lacis, V. Oinas, and M. I. Mishchenko, 2004, J. Geophys. Res., 109, D19105, doi:10.1029/2003JD

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to similar 178 dpa at similar 400 C

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1994-01-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and similar 400 C, the irradiation creep of 20% cold-worked PCA has become dominated by the ''creep disappearance'' phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from similar 20 to 40%. ((orig.))

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to similar 178 dpa at similar 400 C

Energy Technology Data Exchange (ETDEWEB)

Toloczko, M.B. (Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, CA 93106 (United States)); Garner, F.A. (Pacific Northwest Laboratory, Richland, WA 99352 (United States))

1994-09-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and similar 400 C, the irradiation creep of 20% cold-worked PCA has become dominated by the creep disappearance'' phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from similar 20 to 40%. ((orig.))

Direct shortwave forcing of climate by anthropogenic sulfate aerosol: Sensitivity to particle size, composition, and relative humidity

Energy Technology Data Exchange (ETDEWEB)

Nemesure, S.; Wagener, R.; Schwartz, S.E. [Brookhaven National Lab., Upton, New York (United States)

1996-04-01

Recent estimates of global or hemispheric average forcing of climate by anthropogenic sulfate aerosol due to scattering of shortwave radiation are uncertain by more than a factor of 2. This paper examines the sensitivity of forcing to these microphysical properties for the purposes of obtaining a better understanding of the properties required to reduce the uncertainty in the forcing.

The precipitation response of 20%-cold-worked type 316 stainless steel to simulated fusion irradiation

International Nuclear Information System (INIS)

Maziasz, P.J.

1979-01-01

The precipitation response of 20%-cold-worked type 316 stainless steel has been examined after irradiation in HFIR at 380-600 0 C, after irradiation in EBR-II at 500 0 C, and after thermal aging at 600 to 750 0 C. Eta phase forms during exposure to all environments. It constitutes a major portion of the precipitation response, and is rich in Ni, Si and Mo relative to M 23 C 6 after thermal aging. It is not normally reported in 20%-cold-worked type 316 stainless steel. The eta, M 23 C 6 , Laves, sigma, and chi precipitate phases appear at similar temperatures after HFIR, EBR-II, or thermal exposure. There are, however, some differences in relative amounts, size, and distribution of phases among the various environments. Eta phase is the only carbide-type phase observed after irradiation in HFIR from 380-550 0 C. The large cavities associated with it at 380 0 C contribute significantly to swelling. Re-solution of fine M 23 C 6 , eta, and Laves particles and re-precipitation of massive particles of sigma, M 23 C 6 and chi are observed after recrystallization in HFIR. (orig.)

Food irradiation

International Nuclear Information System (INIS)

Paganini, M.C.

1991-06-01

Food treatment by means of ionizing energy, or irradiation, is an innovative method for its preservation. In order to treat important volumes of food, it is necessary to have industrial irradiation installations. The effect of radiations on food is analyzed in the present special work and a calculus scheme for an Irradiation Plant is proposed, discussing different aspects related to its project and design: ionizing radiation sources, adequate civil work, security and auxiliary systems to the installations, dosimetric methods and financing evaluation methods of the project. Finally, the conceptual design and calculus of an irradiation industrial plant of tubercles is made, based on the actual needs of a specific agricultural zone of our country. (Author) [es

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to ∼178 dpa at ∼400 degrees C

International Nuclear Information System (INIS)

Toloczko, M.B.

1993-09-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and ∼400 degrees C, the irradiation creep of 20% cold-worked PCA has become dominated by the open-quotes creep disappearanceclose quotes phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from ∼20 to ∼40%

The Validation of the GEWEX SRB Surface Shortwave Flux Data Products Using BSRN Measurements: A Systematic Quality Control, Production and Application Approach

Science.gov (United States)

Zhang, Taiping; Stackhouse, Paul W., Jr.; Gupta, Shashi K.; Cox, Stephen J.; Mikovitz, J. Colleen; Hinkelman, Laura M.

2013-01-01

The NASA/GEWEX Surface Radiation Budget (SRB) project has produced a 24.5-year continuous record of global shortwave and longwave radiation fluxes at TOA and the Earth's surface from satellite measurements. The time span of the data is from July 1983 to December 2007, and the spatial resolution is 11 latitude11 longitude. The inputs of the latest version (Release 3.0) include the GEOS Version 4.0.3 meteorological information and cloud properties derived from ISCCP DX data. The SRB products are available on 3-hourly, 3-hourly-monthly, daily and monthly time scales. To assess the quality of the product, we extensively validated the SRB data against 5969 site-months of groundbased measurements from 52 Baseline Surface Radiation Network (BSRN) stations. This paper describes first the characteristics of the BSRN data and the GEWEX SRB data, the methodology for quality control and processing of the shortwave BSRN data, and then the systematic SRB-BSRN comparisons. It is found that, except for occasional extreme outliers as seen in scatter plots, the satellite-based surface radiation data generally agree very well with BSRN measurements. Specifically, the bias/RMS for the daily and monthly mean shortwave fluxes are, respectively, -3.6/35.5 and -5.2/23.3W1 m2 under all-sky conditions.

Cytogenetic effects study of in vitro irradiation in peripheral blood lymphocytes of persons working with ionizing radiation

International Nuclear Information System (INIS)

Hadzhidekova, V.; Benova, D.; Bulanova, M.

1998-01-01

The genome radiosensitivity of persons working in the NPP 'Kozloduy', as well as controls are studied. An indicator of genome radiosensitivity is the chromosomal damage induced by in vitro irradiation. A cytogenetic analysis of peripheral blood lymphocytes before and after in vitro irradiation with a dose of 1.5 Gy gamma rays is carried out. The frequency of chromosomal aberrations and micronuclei before and after the irradiation is scored. In certain cases the technique of fluorescent in situ hybridization for recording stable chromosome rearrangements is applied. The data obtained show a decreased chromosome radiosensitivity in occupationally engaged persons as compared to low doses, over a long period of time, may induce the so called 'adaptive response' which makes cells more resistant of subsequent in vitro irradiation with a high dose (author)

Aerosol Direct Radiative Forcing and Forcing Efficiencies at Surface from the shortwave Irradiance Measurements in Abu Dhabi, UAE

Science.gov (United States)

Beegum S, N.; Ben Romdhane, H.; Ghedira, H.

2013-12-01

Atmospheric aerosols are known to affect the radiation balance of the Earth-Atmospheric system directly by scattering and absorbing the solar and terrestrial radiation, and indirectly by affecting the lifetime and albedo of the clouds. Continuous and simultaneous measurements of short wave global irradiance in combination with synchronous spectral aerosol optical depth (AOD) measurements (from 340 nm to 1640 nm in 8 channels), for a period of 1 year from June 2012 to May 2013, were used for the determination of the surface direct aerosol radiative forcing and forcing efficiencies under cloud free conditions in Abu Dhabi (24.42°N, 54.61o E, 7m MSL), a coastal location in United Arab Emirates (UAE) in the Arabian Peninsula. The Rotating Shadow band Pyranometer (RSP, LI-COR) was used for the irradiance measurements (in the spectral region 400-1100 nm), whereas the AOD measurements were carried out using CIMEL Sunphotometer (CE 318-2, under AERONET program). The differential method, which is neither sensitive to calibration uncertainties nor model assumptions, has been employed for estimating forcing efficiencies from the changes in the measured fluxes. The forcing efficiency, which quantifies the net change in irradiance per unit change in AOD, is an appropriate parameter for the characterization of the aerosol radiative effects even if the microphysical and optical properties of the aerosols are not completely understood. The corresponding forcing values were estimated from the forcing efficiencies. The estimated radiative forcing and forcing efficiencies exhibited strong monthly variations. The forcing efficiencies (absolute magnitudes) were highest during March, and showed continuous decrease thereafter to reach the lowest value during September. In contrast, the forcing followed a slightly different pattern of variability, with the highest solar dimming during April ( -60 W m-2) and the minimum during February ( -20 W m-2). The results indicate that the aerosol

Extract of the report of the working party on the handling of irradiated fuel

International Nuclear Information System (INIS)

Berest, P.

1983-01-01

The French government has requested a working party with Prof. Neel in the chair to submit a report on the handling of irradiated fuel. This part of the report concerns the retreated fuels. It gives important elements for the debate and formulates recommendations for radioactive waste management [fr

Characterization of Irradiated and Non-Irradiated Rubber from Automotive Scrap Tires

Science.gov (United States)

Souza, Clécia Moura; Silva, Leonardo G.

The aim of this work was to characterize the samples of irradiated and non-irradiated rubber from automotive scrap tires. Rubber samples from scrap tires were irradiated at irradiation doses of 200, 400 and 600kGy in an electron beam accelerator. Subsequently, both the irradiated and non-irradiated samples were characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), tensile strength mechanical test, and Fourier transform infrared (FTIR) spectrophotometry.

Mechanical Properties and Microstructure of Neutron Irradiated Cold-worked Al-1050 and Al-6063 Alloys

International Nuclear Information System (INIS)

Munitz, A.; Cotler, A; Talianker, M.

1998-01-01

The impact of neutron irradiation on the internal microstructure, mechanical properties and fracture morphology of cold-worked Al-1050 and Al-6063 alloys was studied, using scanning and transmission electron microscopy, and tensile measurements. Specimens consisting of 50 mm long and 6 mm wide gauge sections, were punched out from Al-1050 and Al-6063 23% cold-worked tubes. They were exposed to prolonged neutron irradiation of up to 4.5x10 25 and 8x10 25 thermal neutrons/m 2 (E -3 s -1 . In general, the uniform and total elongation, the yield stress, and the ultimate tensile strength increase as functions of fluence. However, for Al-1050 a decrease in the ultimate tensile strength and yield stress was observed up to a fluence of 1x10 25 thermal neutrons/m 2 which then increase with thermal neutrons fluence. Metallographic examination and fractography for Al-6063 revealed a decrease in the local area reduction of the final fracture necking. This reduction is accompanied by a morphology transition from ductile transgranular shear rupture to a combination of transgranular shear with intergranular dimpled rupture. The intergranular rupture area increases with fluence. In contrast, for Al-1050, fracture morphology remains ductile transgranular shear rupture and the final local area reduction remains almost constant No voids could be observed in either alloy up to the maximum fluence. The dislocation density of cold-worked Al was found to decrease with the thermal neutron fluence. Prolonged annealing of unirradiated cold-worked Al-6063 at 52 degree led to similar results. Thus, it appears that, under our irradiation conditions, whereby the temperature encompassing the samples increases the exposure to this thermal field is the major factor influencing the mechanical properties and microstructure of aluminum alloys

Irradiation risks for hospital staff working with radiotechnetium

International Nuclear Information System (INIS)

Heaton, B.; Brown, L.D.

1975-01-01

The handling of technetium-99m can lead to the irradiation of personnel during the five main stages of its use. Experience shows that the nurses and radiopharmacists are subjected to an exposure difficult to reduce below a certain threshold, but with adequate precautions and job rotation the dose received by the personnel is nevertheless very slight. The practicians themselves, who have been the centre of attention over the last few years, undergo a negligible irradiation [fr

Irradiation risks for hospital staff working with radiotechnetium

Energy Technology Data Exchange (ETDEWEB)

Heaton, B; Brown, L D [Aberdeen Univ. (UK)

1975-10-01

The handling of technetium-99m can lead to the irradiation of personnel during the five main stages of its use. Experience shows that the nurses and radiopharmacists are subjected to an exposure difficult to reduce below a certain threshold, but with adequate precautions and job rotation the dose received by the personnel is nevertheless very slight. The practicians themselves, who have been the centre of attention over the last few years, undergo a negligible irradiation.

Robot Towed Shortwave Infrared Camera for Specific Surface Area Retrieval of Surface Snow

Science.gov (United States)

Elliott, J.; Lines, A.; Ray, L.; Albert, M. R.

2017-12-01

Optical grain size and specific surface area are key parameters for measuring the atmospheric interactions of snow, as well as tracking metamorphosis and allowing for the ground truthing of remote sensing data. We describe a device using a shortwave infrared camera with changeable optical bandpass filters (centered at 1300 nm and 1550 nm) that can be used to quickly measure the average SSA over an area of 0.25 m^2. The device and method are compared with calculations made from measurements taken with a field spectral radiometer. The instrument is designed to be towed by a small autonomous ground vehicle, and therefore rides above the snow surface on ultra high molecular weight polyethylene (UHMW) skis.

Photoreversible Covalent Hydrogels for Soft-Matter Additive Manufacturing.

Science.gov (United States)

Kabb, Christopher P; O'Bryan, Christopher S; Deng, Christopher C; Angelini, Thomas E; Sumerlin, Brent S

2018-05-16

Reversible covalent chemistry provides access to robust materials with the ability to be degraded and reformed upon exposure to an appropriate stimulus. Photoresponsive units are attractive for this purpose, as the spatial and temporal application of light is easily controlled. Coumarin derivatives undergo a [2 + 2] cycloaddition upon exposure to long-wave UV irradiation (365 nm), and this process can be reversed using short-wave UV light (254 nm). Therefore, polymers cross-linked by coumarin groups are excellent candidates as reversible covalent gels. In this work, copolymerization of coumarin-containing monomers with the hydrophilic comonomer N, N-dimethylacrylamide yielded water-soluble, linear polymers that could be cured with long-wave UV light into free-standing hydrogels, even in the absence of a photoinitiator. Importantly, the gels were reverted back to soluble copolymers upon short-wave UV irradiation. This process could be cycled, allowing for recycling and remolding of the hydrogel into additional shapes. Further, this hydrogel can be imprinted with patterns through a mask-based, post-gelation photoetching method. Traditional limitations of this technique, such as the requirement for uniform etching in one direction, have been overcome by combining these materials with a soft-matter additive manufacturing methodology. In a representative application of this approach, we printed solid structures in which the interior coumarin-cross-linked gel is surrounded by a nondegradable gel. Upon exposure to short-wave UV irradiation, the coumarin-cross-linked gel was reverted to soluble prepolymers that were washed away to yield hollow hydrogel objects.

Food irradiation

Energy Technology Data Exchange (ETDEWEB)

Gruenewald, T

1985-01-01

Food irradiation has become a matter of topical interest also in the Federal Republic of Germany following applications for exemptions concerning irradiation tests of spices. After risks to human health by irradiation doses up to a level sufficient for product pasteurization were excluded, irradiation now offers a method suitable primarily for the disinfestation of fruit and decontamination of frozen and dried food. Codex Alimentarius standards which refer also to supervision and dosimetry have been established; they should be adopted as national law. However, in the majority of cases where individual countries including EC member-countries so far permitted food irradiation, these standards were not yet used. Approved irradiation technique for industrial use is available. Several industrial food irradiation plants, partly working also on a contractual basis, are already in operation in various countries. Consumer response still is largely unknown; since irradiated food is labelled, consumption of irradiated food will be decided upon by consumers.

Study on ceramic breeder and related materials by means of work function measurement under irradiation

International Nuclear Information System (INIS)

Luo, G.N.; Terai, T.; Yamawaki, M.; Yamaguchi, K.

2002-01-01

Ceramic breeder materials, Li 2 O, LiAlO 2 and Li 4 SiO 4 , under irradiation have been studied using a Kelvin probe that measures work function changes of materials. Surface charging was observed to influence greatly the probe output, which can be explained qualitatively employing a model concerning induction electric field due to external field and free charges on ceramic surface. It is found that the insulating ceramics could not be studied properly with the Kelvin probe. A probable solution is to heat the ceramics, so as to raise their electric conductivities high enough to root out the surface charging. Also briefly discussed is the application of the probe to metals under ion irradiation. (orig.)

CLARREO shortwave observing system simulation experiments of the twenty-first century: Simulator design and implementation

Energy Technology Data Exchange (ETDEWEB)

Feldman, D.R.; Algieri, C.A.; Ong, J.R.; Collins, W.D.

2011-04-01

Projected changes in the Earth system will likely be manifested in changes in reflected solar radiation. This paper introduces an operational Observational System Simulation Experiment (OSSE) to calculate the signals of future climate forcings and feedbacks in top-of-atmosphere reflectance spectra. The OSSE combines simulations from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report for the NCAR Community Climate System Model (CCSM) with the MODTRAN radiative transfer code to calculate reflectance spectra for simulations of current and future climatic conditions over the 21st century. The OSSE produces narrowband reflectances and broadband fluxes, the latter of which have been extensively validated against archived CCSM results. The shortwave reflectance spectra contain atmospheric features including signals from water vapor, liquid and ice clouds, and aerosols. The spectra are also strongly influenced by the surface bidirectional reflectance properties of predicted snow and sea ice and the climatological seasonal cycles of vegetation. By comparing and contrasting simulated reflectance spectra based on emissions scenarios with increasing projected and fixed present-day greenhouse gas and aerosol concentrations, we find that prescribed forcings from increases in anthropogenic sulfate and carbonaceous aerosols are detectable and are spatially confined to lower latitudes. Also, changes in the intertropical convergence zone and poleward shifts in the subsidence zones and the storm tracks are all detectable along with large changes in snow cover and sea ice fraction. These findings suggest that the proposed NASA Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission to measure shortwave reflectance spectra may help elucidate climate forcings, responses, and feedbacks.

Gemstone dedicated gamma irradiation development

Energy Technology Data Exchange (ETDEWEB)

Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

2007-07-01

The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

Evaluation of the shortwave cloud radiative effect over the ocean by use of ship and satellite observations

Directory of Open Access Journals (Sweden)

T. Hanschmann

2012-12-01

Full Text Available In this study the shortwave cloud radiative effect (SWCRE over ocean calculated by the ECHAM 5 climate model is evaluated for the cloud property input derived from ship based measurements and satellite based estimates and compared to ship based radiation measurements. The ship observations yield cloud fraction, liquid water path from a microwave radiometer, cloud bottom height as well as temperature and humidity profiles from radiosonde ascents. Level-2 products of the Satellite Application Facility on Climate Monitoring (CM~SAF from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI have been used to characterize clouds. Within a closure study six different experiments have been defined to find the optimal set of measurements to calculate downward shortwave radiation (DSR and the SWCRE from the model, and their results have been evaluated under seven different synoptic situations. Four of these experiments are defined to investigate the advantage of including the satellite-based cloud droplet effective radius as additional cloud property. The modeled SWCRE based on satellite retrieved cloud properties has a comparable accuracy to the modeled SWCRE based on ship data. For several cases, an improvement through introducing the satellite-based estimate of effective radius as additional information to the ship based data was found. Due to their different measuring characteristics, however, each dataset shows best results for different atmospheric conditions.

Spectral composition of shortwave radiation reflected and deep penetrating into snow near the Barentsburg settlement (Svalbard

Directory of Open Access Journals (Sweden)

P. N. Svyashchennikov

2015-01-01

Full Text Available Data on spectral composition of shortwave radiation that is reflected from snow and penetrates deep into the snow cover obtained near the Barentsburg settlement (Svalbard are discussed in the paper. Measurements were made by the use of the spectral radiometer TriOS Ramses within the wavelength range of 280–950 nm. The results will allow more proper taking account of the anthropogenic pollution effects on the radiative properties of snow cover under conditions of industrial activity related to the coal extraction and burning in Barentsburg.

Insights into the working mechanism of water filtered infrared A (wIRA) irradiation on Chlamydia trachomatis serovar E

Science.gov (United States)

Kuratli, Jasmin; Pesch, Theresa; Marti, Hanna; Blenn, Christian; Borel, Nicole

2018-02-01

Infections with Chlamydia trachomatis are the major cause for infectious blindness and still represent the most common bacterial sexually transmitted disease worldwide. Considering the possible side effects of antibiotic therapy and the increasing threat of antibiotic resistance, alternative therapeutic strategies are needed. Previous studies showed a reduction of C. trachomatis infectivity after irradiation with water filtered infrared A alone (wIRA) or in combination with visible light (wIRA/VIS). In this study, we aimed to gain further insight into the working mechanism of wIRA/VIS by analyzing cytokine and chemokine levels of infected and non-infected HeLa cells following triple dose irradiation at 24, 36 and 40 hours post infection. Subsequently, we examined the influence of cytokines on irradiation and chlamydial infection using a cytokine/chemokine inhibitor (Azelastine) and by IL-6 and IL-8 gene silencing. A triple dose irradiation significantly reduced chlamydial infectivity in HeLa cells without inducing the chlamydial stress response. The reducing effect was present regardless of the addition of cycloheximide (CHX), a host protein synthesis inhibitor. Chlamydial infection, wIRA/VIS treatment and the combination of both revealed a similar release pattern of a subset of pro-inflammatory cytokines (IL-6, IL-8, RANTES, Serpin E1). The addition of Azelastine induced the chlamydial stress response in non-irradiated samples. This effect was even more pronounced in wIRA/VIS-treated conditions. Silencing of IL-6 and IL-8 resulted in a lower chlamydial infectivity. However, wIRA/VIS treatment of infected and silenced cells reduced the chlamydial infectivity similar to wIRA/VIS treated control cells. Further studies are needed to elucidate the working mechanism of wIRA/VIS.

Neutron irradiation effects in reactor pressure vessel steels and weldments. Working document

International Nuclear Information System (INIS)

1998-10-01

As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. A separate abstract was prepared for the introduction and for each of the eleven chapters, which are: 1. Reactor Pressure Vessel Design, 2. Reactor Pressure Materials, 3. WWER Pressure Vessels, 4. Determination of Mechanical Properties, 5. Neutron Exposure, 6. Methodology of Irradiation Experiments, 7. Effect of Irradiation on Mechanical Properties, 8. Mechanisms of Irradiation Embrittlement, 9. Modelling of Irradiation Damage, 10. Annealing of Irradiation Damage, 11. Safety Assessment using Surveillance Programmes and Data Bases

Energy and carbon balances in cheatgrass, an essay in autecology. [Shortwave radiation, radiowave radiation

Energy Technology Data Exchange (ETDEWEB)

Hinds, W.T.

1975-01-01

An experiment to determine the fates of energy and carbon in cheatgrass (Bromus tectorum L.) was carried out on steep (40/sup 0/) north- and south-facing slopes on a small earth mound, using many small lysimeters to emulate swards of cheatgrass. Meteorological conditions and energy fluxes that were measured included air and soil temperatures, relative humidity, wind speed, incoming shortwave radiation, net all-wave radiation, heat flux to the soil, and evaporation and transpiration separately. The fate of photosynthetically fixed carbon during spring growth was determined by analysis of the plant tissues into mineral nutrients, crude protein, crude fat, crude fiber, and nitrogen-free extract (NFE) for roots, shoots, and seeds separately. (auth)

Developments of sausages in a z-pinch with short-wave perturbation of a boundary

International Nuclear Information System (INIS)

Vikhrev, V.V.; Ivanov, V.V.; Rozanova, G.A.

1989-01-01

A numeric simulation of sausage evolution in z-pinch during short-wave excitation of the boundary of plasma column pinch is carried out. The simulation has shown that due to nonlinear development of sausages in a pinch plasma colomn the cavities filled with a magnetic field in a rarefied pinch plasma are formed. Simultaneously compact column of tense plasma whose temperature is much higher than the average temperature of pinch plasma column are formed on the pinch axis. In the region of inlet in the cavity plasma is radially directed due to ponderomotoric force 1/2 x jB up to velocities greatly increasing the thermal velocity of ions in a plasma column

Analysis of creep data from MOTA irradiation of 20% cold worked 316 stainless steel

International Nuclear Information System (INIS)

Garner, F.A.; Toloczko, M.B.; Puigh, R.J.

1992-01-01

The objective of this study is to provide insight into the relationship between void swelling, irradiation creep and applied stress. This insight will be used to develop irradiation creep correlations for fusion applications. Analysis of creep data for 20% cold worked 316 stainless steel irradiated in FFTF/MOTA demonstrates that creep-swelling coupling coefficient is not a strong function of temperature and can be assumed to be -0.6 x 10 -2 MPa -1 in the range 400-600 C. It appears, however, that the creep compliance B o is a moderately strong function of temperature and alloy composition. The latter dependency arises primarily because derived values of B o unavoidably incorporate precipitation-related strains that cannot be easily separated from contributions arising from true creep. It has also been found that at ∼550-600 C there is an upper limit on the total diametral strain rate at 0.33%/dpa. In contrast to the conclusion of an earlier experiment, this limitation does not arise initially from the total disappearance of creep, however. The creep rate first increases with the onset of swelling and then diminishes as the swelling rate increases, disappearing only when the swelling rate reaches its steady state value

Determination of atmospheric parameters to estimate global radiation in areas of complex topography: Generation of global irradiation map

Energy Technology Data Exchange (ETDEWEB)

Batlles, F.J.; Bosch, J.L. [Dpto. Fisica Aplicada, Universidad de Almeria, 04120 Almeria (Spain); Tovar-Pescador, J. [Dpto. Fisica, Universidad de Jaen, 23071 Jaen (Spain); Martinez-Durban, M. [Dpto. Ingenieria Lenguajes y Computacion, Universidad de Almeria, 04120 Almeria (Spain); Ortega, R. [Dpto. Edafologia y Quimica Agricola, Universidad de Almeria, 04120 Almeria (Spain); Miralles, I. [Dpto. Edafologia y Quimica Agricola, Universidad de Granada, 28071 Granada (Spain)

2008-02-15

Incoming shortwave solar radiation is an important parameter in environmental applications. A detailed spatial and temporal analysis of global solar radiation on the earth surface is needed in many applications, ranging from solar energy uses to the study of agricultural, forest and biological processes. At local scales, the topography is the most important factor in the distribution of solar radiation on the surface. The variability of the elevation, the surface orientation and the obstructions due to elevations are a source of great local differences in insolation and, consequently, in other variables as ground temperature. For this reason, several models based on GIS techniques have been recently developed, integrating topography to obtain the solar radiation on the surface. In this work, global radiation is analyzed with the Solar Analyst, a model implemented on ArcView, that computes the topographic parameters: altitude, latitude, slope and orientation (azimuth) and shadow effects. Solar Analyst uses as input parameters the diffuse fraction and the transmittance. These parameters are not usually available in radiometric networks in mountainous areas. In this work, a method to obtain both parameters from global radiation is proposed. Global radiation data obtained in two networks of radiometric stations is used: one located in Sierra Magina Natural Park (Spain) with 11 stations and another one located on the surroundings of Sierra Nevada Natural Park (Spain) with 14 stations. Daily solar irradiation is calculated from a digital terrain model (DTM), the daily diffuse fraction, K, and daily atmospheric transmittivity, {tau}. Results provided by the model have been compared with measured values. An overestimation for high elevations is observed, whereas low altitudes present underestimation. The best performance was also reported during summer months, and the worst results were obtained during winter. Finally, a yearly global solar irradiation map has been

Nonlinear effects in the propagation of shortwave transverse sound in pure superconductors

International Nuclear Information System (INIS)

Gal'perin, Y.

1982-01-01

Various mechanisms are analyzed which lead to nonlinear phenomena (e.g., the dependence of the absorption coefficient and of the velocity of sound on its intensity) in the propagation of transverse shortwave sound in pure superconductors (the wavelength of the sound being much less than the mean free path of the quasiparticles). It is shown that the basic mechanism, over a wide range of superconductor parameters and of the sound intensity, is the so-called momentum nonlinearity. The latter is due to the distortion (induced by the sound wave) of the quasimomentum distribution of resonant electrons interacting with the wave. The dependences of the absorption coefficient and of the sound velocity on its intensity and on the temperature are analyzed in the vicinity of the superconducting transition point. The feasibility of an experimental study of nonlinear acoustic phenomena in the case of transverse sound is considered

Irradiation of food

International Nuclear Information System (INIS)

Lindell, B.; Danielsson-Tham, M.L.; Hoel, C.

1983-01-01

A committee has on instructions from the swedish government made an inquiry into the possible effects on health and working environment from irradition of food. In this report, a review is presented on the known positiv and negative effects of food irradiation Costs, availabilty, shelf life and quality of irradiated food are also discussed. According to the report, the production of radiolysis products during irradiation is not easily evaluated. The health risks from irradiation of spices are estimated to be lower than the risks associated with the ethenoxid treatment presently used. (L.E.)

Irradiation embrittlement of pressure vessel steels

International Nuclear Information System (INIS)

Brumovsky, M.; Vacek, M.

1975-01-01

A Standard Research Programme on Irradiation Embrittlement of Pressure Vessel Steels was approved by the Coordinating Meeting on the 12th May 1972 at the Working Group on Engineering Aspects of Irradiation Embrittlement of Pressure Vessel Steels. This Working Group was set up by the International Atomic Energy Agency in Vienna. Seven countries with their research institutes agreed on doing irradiation experiments according to the approved programme on steel A533 B from the U.S. HSST Programme. The Czechoslovak contribution covering tensile and impact testing of non-irradiated steel and steel irradiated at 280degC to 1.3 x 10 23 n/m 2 (E above 1 MeV) is presented in this report. As an additional part the same set of experiments was carried out on two additional steels - A 542 and A 543, made in SKODA Works for comparison of their irradiation embrittlement and hardening with A533 B steel. (author)

Six years working experience of the Marcoule plant for treatment of irradiated fuel

International Nuclear Information System (INIS)

Jouannaud, C.

1964-01-01

The irradiated fuel treatment plant at Marcoule began treating rods from the pile G 1 in July 1958. These six years experience of the plant in operation have led to the confirmation or revision of the original ideas concerning the process as well as the technology or methods of exploitation. The process as a whole has suffered little modification, the performances having proved better than originally foreseen; the only alterations made were justified by greater simplicity of operation, better nuclear security (criticality) or for technological reasons. The processes of plutonium reduction from valency IV to valency III by uranium IV, and of concentration of fission product solutions in the presence of formaldehyde, have always given complete satisfaction. The initial concept of direct maintenance of the installations has been justified by experience. Certain maintenance jobs, originally considered impossible after the start of operations, have proved feasible and have been carried out under acceptable conditions; a number of examples are given. From experience it has been possible to define optimal conditions for the design of these installations such as to provide a maximum in robustness and ease of maintenance. The advantages of continuously-operating equipment have been shown. Certain installations have been altered in accordance with these new ideas. Analytical checking in the laboratory has been profoundly modified, and the plans adopted are such that complete safety in work on radioactive solutions is compatible with a very good working speed. Experience has also shown the advantages of having a group on the spot to carry out short-term applied studies. Finally, a strict working discipline and excellent collaboration with the radiation protection service have enabled us to reach the end of these six years, during some of which the exploitation was intensive, without irradiation accident. (authors) [fr

Forcings and feedbacks in the GeoMIP ensemble for a reduction in solar irradiance and increase in CO2

Science.gov (United States)

Huneeus, Nicolas; Boucher, Olivier; Alterskjær, Kari; Cole, Jason N. S.; Curry, Charles L.; Ji, Duoying; Jones, Andy; Kravitz, Ben; Kristjánsson, Jón Egill; Moore, John C.; Muri, Helene; Niemeier, Ulrike; Rasch, Phil; Robock, Alan; Singh, Balwinder; Schmidt, Hauke; Schulz, Michael; Tilmes, Simone; Watanabe, Shingo; Yoon, Jin-Ho

2014-05-01

The effective radiative forcings (including rapid adjustments) and feedbacks associated with an instantaneous quadrupling of the preindustrial CO2 concentration and a counterbalancing reduction of the solar constant are investigated in the context of the Geoengineering Model Intercomparison Project (GeoMIP). The forcing and feedback parameters of the net energy flux, as well as its different components at the top-of-atmosphere (TOA) and surface, were examined in 10 Earth System Models to better understand the impact of solar radiation management on the energy budget. In spite of their very different nature, the feedback parameter and its components at the TOA and surface are almost identical for the two forcing mechanisms, not only in the global mean but also in their geographical distributions. This conclusion holds for each of the individual models despite intermodel differences in how feedbacks affect the energy budget. This indicates that the climate sensitivity parameter is independent of the forcing (when measured as an effective radiative forcing). We also show the existence of a large contribution of the cloudy-sky component to the shortwave effective radiative forcing at the TOA suggesting rapid cloud adjustments to a change in solar irradiance. In addition, the models present significant diversity in the spatial distribution of the shortwave feedback parameter in cloudy regions, indicating persistent uncertainties in cloud feedback mechanisms.

Optimized chemical composition, working and heat treatment condition for resistance to irradiation assisted stress corrosion cracking of cold worked 316 and high-chromium austenitic stainless steel

International Nuclear Information System (INIS)

Yonezawa, Toshio; Iwamura, Toshihiko; Fujimoto, Koji; Ajiki, Kazuhide

2000-01-01

The authors have reported that the primary water stress corrosion cracking (PWSCC) in baffle former bolts made of austenitic stainless steels for PWR after long-term operation is caused by irradiation-induced grain boundary segregation. The resistance to PWSCC of simulated austenitic stainless steels whose chemical compositions are simulated to the grain boundary chemical composition of 316 stainless steel after irradiation increased with decrease of the silicon content, increases of the chromium content, and precipitation of M 23 C 6 carbides at the grain boundaries. In order to develop resistance to irradiation assisted stress corrosion cracking in austenitic stainless steels, optimized chemical compositions and heat treatment conditions for 316CW and high-chromium austenitic stainless steels for PWR baffle former bolts were investigated. For 316CW stainless steel, ultra-low-impurities and high-chromium content are beneficial. About 20% cold working before aging and after solution treatment has also been recommended to recover sensitization and make M 23 C 6 carbides coherent with the matrix at the grain boundaries. Heating at 700 to 725degC for 20 to 50 h was selected as a suitable aging procedure. Cold working of 5 to 10% after aging produced the required mechanical properties. The optimized composition of the high-chromium austenitic stainless steel contents 30% chromium, 30% nickel, and ultra-low impurity levels. This composition also reduces the difference between its thermal expansion coefficient and that of 304 stainless steel for baffle plates. Aging at 700 to 725degC for longer than 40 h and cold working of 10 to 15% after aging were selected to meet mechanical property specifications. (author)

Dosimetry for Crystals Irradiation

CERN Document Server

Lecomte, Pierre

2005-01-01

Before shipment to CMS, all PbWO4 crystals produced in China are irradiated there with 60 Co , in order to insure that the induced absorption coefficient is within specifications. Acceptance tests at CERNand at ENEA also include irradiation with gamma rays from 60 Co sources. There were initially discrepancies in quoted doses and doserates as well as in induced absorption coefficients. The present work resolves the discrepancies in irradiation measurements and defines common dosimetry methods for consistency checks between irradiation facilities.

Integrated modeling of second phase precipitation in cold-worked 316 stainless steels under irradiation

International Nuclear Information System (INIS)

Mamivand, Mahmood; Yang, Ying; Busby, Jeremy T.; Morgan, Dane

2017-01-01

The current work combines the Cluster Dynamics (CD) technique and CALPHAD-based precipitation modeling to address the second phase precipitation in cold-worked (CW) 316 stainless steels (SS) under irradiation at 300–400 °C. CD provides the radiation enhanced diffusion and dislocation evolution as inputs for the precipitation model. The CALPHAD-based precipitation model treats the nucleation, growth and coarsening of precipitation processes based on classical nucleation theory and evolution equations, and simulates the composition, size and size distribution of precipitate phases. We benchmark the model against available experimental data at fast reactor conditions (9.4 × 10"–"7 dpa/s and 390 °C) and then use the model to predict the phase instability of CW 316 SS under light water reactor (LWR) extended life conditions (7 × 10"–"8 dpa/s and 275 °C). The model accurately predicts the γ' (Ni_3Si) precipitation evolution under fast reactor conditions and that the formation of this phase is dominated by radiation enhanced segregation. The model also predicts a carbide volume fraction that agrees well with available experimental data from a PWR reactor but is much higher than the volume fraction observed in fast reactors. We propose that radiation enhanced dissolution and/or carbon depletion at sinks that occurs at high flux could be the main sources of this inconsistency. The integrated model predicts ~1.2% volume fraction for carbide and ~3.0% volume fraction for γ' for typical CW 316 SS (with 0.054 wt% carbon) under LWR extended life conditions. Finally, this work provides valuable insights into the magnitudes and mechanisms of precipitation in irradiated CW 316 SS for nuclear applications.

Food irradiation and the consumer

International Nuclear Information System (INIS)

Thomas, P.A.

1990-01-01

The poster presents a review of research work undertaken on the perception and understanding that consumers have of food irradiation. Food irradiation is not a revolutionary new food processing technique, in fact it is probably one of the most investigated methods presently available. Many countries such as Belgium, France, Denmark, Italy, Spain, the Netherlands and the United States of America permit food irradiation. In Britain it is presently banned although this is currently under review. Awareness of food irradiation by the general public in Britain, although not extensively researched would appear to be increasing, especially in the light of recent media coverage. New quantitative and qualitative work indicates that the general public are concerned about the safety and effectiveness of food irradiation. Research has shown that a large proportion of consumers in Britain, if given the opportunity to purchase irradiated food, would not do so. Further exploration into this response revealed the fact that consumers are confused over what food irradiation is. In addition, there is concern over the detection of irradiated food. The views presented in this paper, of the consumer reaction to irradiated food are of great importance to those involved in the food industry and industries allied to it, which are ultimately dependent on the consumer for their commercial survival. (author)

DAMAGE IN MOLYBDENUM ASSOCIATED WITH NEUTRON IRRADIATION AND SUBSEQUENT POST-IRRADIATION ANNEALING

Energy Technology Data Exchange (ETDEWEB)

Mastel, B.

1963-07-23

Molybdemum containing carbon was studied in an attempt to establish the combined effect of impurity content and neutron irradiation on the properties and structure of specific metals. Molybdenum foils were punched into discs and heat treated in vacuum. They were then slow-cooled and irradiated. After irradiation and subsequent decay of radioactivity to a low level the foils were subjected to x-ray diffraction measurements. Cold-worked foils with less than 10 ppm carbon showed no change in microstructure due to irradiation. Molybdenum foils that were annealed prior to irradiation showed spot defects. In foils containing up to 500 ppm carbon, it was concluded that the small loops present after irradiation are due to the clustering of point defects at interstitial carbon atoms, followed by collapse to form a dislocation loop. The amount of lattice expansion after irradiation was strongly dependent on impurity content. Neutron irradiation was found to reduce the number of active slip systems. (M.C.G.)

ATF Neutron Irradiation Program Technical Plan

Energy Technology Data Exchange (ETDEWEB)

Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

2016-03-01

The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.

Does variation in mineral composition alter the short-wave light scattering properties of desert dust aerosol?

International Nuclear Information System (INIS)

Smith, Andrew J.A.; Grainger, Roy G.

2014-01-01

Mineral dust aerosol is a major component of natural airborne particulates. Using satellite measurements from the visible and near-infrared, there is insufficient information to retrieve a full microphysical and chemical description of an aerosol distribution. As such, refractive index is one of many parameters that must be implicitly assumed in order to obtain an optical depth retrieval. This is essentially a proxy for the dust mineralogy. Using a global soil map, it is shown that as long as a reasonable refractive index for dust is assumed, global dust variability is unlikely to cause significant variation in the optical properties of a dust aerosol distribution in the short-wave, and so should not greatly affect retrievals of mineral dust aerosol from space by visible and near-infrared radiometers. Errors in aerosol optical depth due to this variation are expected to be ≲1%. The work is framed around the ORAC AATSR aerosol retrieval, but is equally applicable to similar satellite retrievals. In this case, variations in the top-of-atmosphere reflectance caused by mineral variation are within the noise limits of the instrument. -- Highlights: • Global variation in dust aerosol refractive index is quantified using soil maps. • Resulting visible light scattering properties have limited variability. • Satellite aerosol retrievals do not need to account for varying dust refractive indices

Special irradiation techniques

International Nuclear Information System (INIS)

Colomez, Gerard; Veyrat, J.F.

1981-01-01

Irradiation trials conducted on materials-testing reactors should provide a better understanding of the phenomena which characterize the working and evolution in time of electricity-generating nuclear reactors. The authors begin by outlining the objectives behind experimental irradiation (applied to the various nuclear chains) and then describe the special techniques deployed to achieve these objectives [fr

Post-factum detection of food irradiation

International Nuclear Information System (INIS)

Meier, W.

1991-01-01

Irradiation of food containing bones or shells can be detected with a high degree of certainty by means of ESR and by analysis of the volatile hydrocarbons or of the o-tyrosine. The last two methods are used for identification of irradiated pure meat samples. Detection of irradiation in spices and dried vegetables is possible with the thermoluminescence method and ESR, if non-irradiated control samples are available. These methods are being tested in the period 1990/1991 by an EC Commission-sponsored interlaboratory study of spices and food containing bones or shells, whereas the two chemical methods need further optimisation by work done in smaller working groups. (orig.) [de

Using GIS data and satellite derived irradiance to optimize siting of PV installations in Switzerland

Science.gov (United States)

Kahl, Annelen; Nguyen, Viet-Anh; Bartlett, Stuart; Sossan, Fabrizio; Lehning, Michael

2016-04-01

For a successful distribution strategy of PV installations, it does not suffice to choose the locations with highest annual total irradiance. Attention needs to be given to spatial correlation patterns of insolation to avoid large system-wide variations, which can cause extended deficits in supply or might even damage the electrical network. One alternative goal instead is to seek configurations that provide the smoothest energy production, with the most reliable and predictable supply. Our work investigates several scenarios, each pursuing a different strategy for a future renewable Switzerland without nuclear power. Based on an estimate for necessary installed capacity for solar power [Bartlett, 2015] we first use heuristics to pre-select realistic placements for PV installations. Then we apply optimization methods to find a subset of locations that provides the best possible combined electricity production. For the first part of the selection process, we use a DEM to exclude high elevation zones which would be difficult to access and which are prone to natural hazards. Then we use land surface cover information to find all zones with potential roof area, deemed suitable for installation of solar panels. The optimization employs Principal Component Analysis of satellite derived irradiance data (Surface Incoming Shortwave Radiation (SIS), based on Meteosat Second Generation sensors) to incorporate a spatial aspect into the selection process that does not simply maximize annual total production but rather provides the most robust supply, by combining regions with anti-correlated cloud cover patterns. Depending on the initial assumptions and constraints, the resulting distribution schemes for PV installations vary with respect to required surface area, annual total and lowest short-term production, and illustrate how important it is to clearly define priorities and policies for a future renewable Switzerland.

ACPSEM ROSG TBI working group recommendations for quality assurance in total body irradiation

International Nuclear Information System (INIS)

Nelligan, Raelene; Bailey, Michael; Tran, Thu; Baldwin, Zoe

2015-01-01

The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) radiation oncology specialty group (ROSG) formed a series of working groups in 2011 to develop recommendations for guidance of radiation oncology medical physics practice within the Australasian setting. These recommendations are intended to provide guidance for safe work practices and a suitable level of quality control without detailed work instructions. It is the responsibility of the medical physicist to ensure that locally available equipment and procedures are sufficiently sensitive to establish compliance to these recommendations. The recommendations are endorsed by the ROSG, and have been subject to independent expert reviews. For the Australian audience, these recommendations should be read in conjunction with the tripartite radiation oncology practice standards [1, 2]. This publication presents the recommendations of the ACPSEM total body irradiation working group (TBIWG) and has been developed in alignment with other international associations. However, these recommendations should be read in conjunction with relevant national, state or territory legislation and local requirements, which take precedence over the ACPSEM recommendations. It is hoped that the users of this and other ACPSEM recommendations will contribute to the development of future versions through the ROSG of the ACPSEM. This document serves as a guideline for calibration and quality assurance of equipment used for TBI in Australasia.

Multiyear Statistics of 2-D Shortwave Radiative Effects at Three ARM Sites

Science.gov (United States)

Varnai, Tamas

2010-01-01

This study examines the importance of horizontal photon transport effects, which are not considered in the 1-D calculations of solar radiative heating used by most atmospheric dynamical models. In particular, the paper analyzes the difference between 2-D and 1-D radiative calculations for 2-D vertical cross-sections of clouds that were observed at three sites over 2- to 3-year periods. The results show that 2-D effects increase multiyear 24-hour average total solar absorption by about 4.1 W/sq m, 1.2 W/sq m, and 0.3 W/sq m at a tropical, mid-latitude, and arctic site, respectively. However, 2-D effects are often much larger than these average values, especially for high sun and for convective clouds. The results also reveal a somewhat unexpected behavior, that horizontal photon transport often enhances solar heating even for oblique sun. These findings underscore the need for fast radiation calculation methods that can allow atmospheric dynamical simulations to consider the inherently multidimensional nature of shortwave radiative processes.

Gemstone enhancing dedicated gamma irradiator development

International Nuclear Information System (INIS)

Omi, Nelson Minoru

2006-01-01

The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to it's poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator raised in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations were performed. With the definitive irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. (author)

Microbiological decontamination of some herbs by irradiation

International Nuclear Information System (INIS)

Migdal, W.; Owczarczyk, H.B.

1996-01-01

The research work on the microbiological decontamination of the medical herbs by electron beam was carried out. The seven samples of the herbs granules were irradiated at the doses 3, 6 and 10 kGy. It has been shown, that D10 values are varied in several samples after irradiation. Additional, research work, by gas chromatographic method, on the composition volatile oils (salvia, orange, peppermint and anise), after irradiation at the dose 4.4 and 8.8 kGy was carried out. It was not significant differences in the compositions between control and irradiated oils. (author). 12 figs, 2 tabs

Impact of Aerosols on Shortwave and Photosynthetically Active Radiation Balance over Sub-tropical Region in South Asia: Observational and Modeling Approach

Science.gov (United States)

Subba, T.; Pathak, B.

2016-12-01

The North-East Indian Region (NER) (22-30ºN, 89-98ºE) in south Asia sandwiched between two global biodiversity hotspots namely, Himalaya and Indo-Burma, assumes significance owing to its unique topography with mountains in the north, east and south and densely populated Indo Gangetic plains (IGP) towards the west resulting in complex aerosol system. Multi-year (2010-2014) concurrent measurements of aerosol properties and the shortwave radiation budget are examined over four geographically distinct stations of NER operational under Indian Space Research organization's ARFINET (Aerosol Radiative Forcing over India NETwork). An attempt has been made to lessen the ambiguity of forcing estimation by validating the radiative transfer modelled ARF with the CNR4 net radiometer measured values (r2 0.98). The Normalized Difference Vegetation Index and its dependence on the extinction of the photosynthetically active radiation (PAR) due to aerosol are assessed. The spring time enhancement of aerosols in the column has shown significant surface cooling (ARF = -48 ± 5 Wm-2) over the region, while the very high Black Carbon (BC) mass concentrations near the surface (SSA > 0.8) leads to significant atmospheric warming (ARF = +41 ± 7 Wm-2) in the shortwave range. Radiative forcing estimates reveal that the atmospheric forcing by BC could be as high as +30Wm-2 over the western part, which are significantly higher than the eastern part with a consequent heating rate of 1.5 K day-1 revealing an east-west asymmetry over NER. The impact of BC aerosols on the photosynthetic rate varies among different locations ranging from -5±2 Wm-2 to -25±3 Wm-2. Almost 70% of the total atmospheric shortwave radiative absorption is attributed to just 10% contribution of Black Carbon (BC) to total mass concentration and causes a reduction of more than 30% of PAR reaching the surface over Brahmaputra valley due to direct radiative effect. Comparison of previous and the present study shows highest

Requirements for work of nurses and technicians in a centre for specialized health care of irradiated persons

International Nuclear Information System (INIS)

Blaha, M.; Pidrman, V.; Vanasek, J.; Brandova, J.

1982-01-01

Experience is presented with the training of nurses of the Centre of Specialized Health Care For Irradiated Persons of the Unit for Treatment of Hematological Diseases, which may serve as the model for the treatment of acute radiation syndrome. The concept of the training course is presented. The basic requirement is a nursing school diploma and a post-secondary training course (theoretical and practical, including the preparation of the work place, the treatment of patients, psychotherapy, microbial checks, etc.). Experience has shown that 2 to 3 years work in this field is needed to master the required theoretical knowledge and skills. (J.B.)

Requirements for work of nurses and technicians in a centre for specialized health care of irradiated persons

Energy Technology Data Exchange (ETDEWEB)

Blaha, M; Pidrman, V; Vanasek, J; Brandova, J [Vojensky Lekarsky Vyzkumny a Doskolovaci Ustav J.E. Purkyne, Hradec Kralove (Czechoslovakia)

1982-12-01

Experience is presented with the training of nurses of the Centre of Specialized Health Care For Irradiated Persons of the Unit for Treatment of Hematological Diseases, which may serve as the model for the treatment of acute radiation syndrome. The concept of the training course is presented. The basic requirement is a nursing school diploma and a post-secondary training course (theoretical and practical, including the preparation of the work place, the treatment of patients, psychotherapy, microbial checks, etc.). Experience has shown that 2 to 3 years work in this field is needed to master the required theoretical knowledge and skills.

Food irradiation: the facts

International Nuclear Information System (INIS)

Webb, Tony; Lang, Tim

1987-01-01

The London Food Commission summarizes its concerns about the use of food irradiation in the U.K. resulting from its working group surveys of general public opinion, trading standard officers and the food industry in the U.K., and from experience in countries already permitting irradiation to a variety of foods. (U.K.)

Parametric relationships for gamma dose and irradiation homogeneity in a sewage sludge irradiator

International Nuclear Information System (INIS)

Krishnamurthy, K.

1986-01-01

A study on the inter-relationships between factors governing γ dose and irradiation homogeneity in a sewage sludge irradiator is presented here. The analysis involves a 60 Co irradiator of cylindrical irradiation geometry with batchwise operation for hygienisation of liquid sludge. The influence of the parameters such as the source-target geometry, strength of 60 Co sources in the irradiator, hygienisation dose and rheological and hydraulic characteristics of sewage sludge on the selection of the three critical factors viz. the pumping rate (P) required to maintain turbulent flow regime in the irradiation zone; the mininum re-circulation time (Tsub(m)) essential to achieve a certain degree of homogeneity of dose absorption in the fluid; and the irradiation time (Tsub(i)) required to impart the necessary dose for the desired hygienisation effect in the sludge has been discussed in detail and inter-relationships among these three factors have been worked out. The applicability of the relationships to a typical operating plant has also been elucidated. (author)

Total lymphoid irradiation

International Nuclear Information System (INIS)

Anon.

1980-01-01

An outline review notes recent work on total lymphoid irradiation (TLI) as a means of preparing patients for grafts and particularly for bone-marrow transplantation. T.L.I. has proved immunosuppressive in rats, mice, dogs, monkeys and baboons; when given before bone-marrow transplantation, engraftment took place without, or with delayed rejection or graft-versus-host disease. Work with mice has indicated that the thymus needs to be included within the irradiation field, since screening of the thymus reduced skin-graft survival from 50 to 18 days, though irradiation of the thymus alone has proved ineffective. A more lasting tolerance has been observed when T.L.I. is followed by an injection of donor bone marrow. 50% of mice treated in this way accepted allogenic skin grafts for more than 100 days, the animals proving to be stable chimeras with 50% of their peripheral blood lymphocytes being of donor origin. Experiments of a similar nature with dogs and baboons were not so successful. (U.K.)

Spectralon BRDF and DHR Measurements in Support of Satellite Instruments Operating Through Shortwave Infrared

Science.gov (United States)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-01-01

Satellite instruments operating in the reflective solar wavelength region require accurate and precise determination of the Bidirectional Reflectance Distribution Functions (BRDFs) of the laboratory and flight diffusers used in their pre-flight and on-orbit calibrations. This paper advances that initial work and presents a comparison of spectral Bidirectional Reflectance Distribution Function (BRDF) and Directional Hemispherical Reflectance (DHR) of Spectralon*, a common material for laboratory and onorbit flight diffusers. A new measurement setup for BRDF measurements from 900 nm to 2500 nm located at NASA Goddard Space Flight Center (GSFC) is described. The GSFC setup employs an extended indium gallium arsenide detector, bandpass filters, and a supercontinuum light source. Comparisons of the GSFC BRDF measurements in the ShortWave InfraRed (SWIR) with those made by the NIST Spectral Trifunction Automated Reference Reflectometer (STARR) are presented. The Spectralon sample used in this study was 2 inch diameter, 99% white pressed and sintered Polytetrafluoroethylene (PTFE) target. The NASA/NIST BRDF comparison measurements were made at an incident angle of 0 deg and viewing angle of 45 deg. Additional BRDF data not compared to NIST were measured at additional incident and viewing angle geometries and are not presented here The total combined uncertainty for the measurement of BRDF in the SWIR range made by the GSFC scatterometer is less than 1% (k=1). This study is in support of the calibration of the Joint Polar Satellite System (JPSS) Radiation Budget Instrument (RBI) and Visible Infrared Imaging Radiometer Suite (VIIRS) of and other current and future NASA remote sensing missions operating across the reflected solar wavelength region.

New multipurpose gamma-irradiation facility

Energy Technology Data Exchange (ETDEWEB)

Huebner, G

1985-01-01

In the past 3 years much work has been done in the G.D.R. on food irradiation. The experiments have shown that this treatment gives favourable results in many products such as spices, onions, potatoes, chicken, animal feeds, fodder yeast, drugs and vaccines. Economic aspects of food irradiation require the effective use of an irradiation plant and cobalt-60. Therefore, a new multipurpose irradiation facility was developed, applicable as an onion irradiator with a capacity of about 15 ton/h and for the simultaneous irradiation of different products (spices, animal feed, chicken, etc.) in closed product boxes with a size of 1.2 m x 1.0 m x 1.2 m. A microcomputer controls the transport of product boxes around the gamma sources.

Short-Wave Near-Infrared Spectrometer for Alcohol Determination and Temperature Correction

Directory of Open Access Journals (Sweden)

Qingbo Fu

2012-01-01

Full Text Available A multichannel short-wave near-infrared (SW-NIR spectrometer module based on charge-coupled device (CCD detection was designed. The design relied on a tungsten lamp enhanced by light emitting diodes, a fixed grating monochromator and a linear CCD array. The main advantages were high optical resolution and an optimized signal-to-noise ratio (0.24 nm and 500, resp. in the whole wavelength range of 650 to 1100 nm. An application to alcohol determination using partial least squares calibration and the temperature correction was presented. It was found that the direct transfer method had significant systematic prediction errors due to temperature effect. Generalized least squares weighting (GLSW method was utilized for temperature correction. After recalibration, the RMSEP found for the 25°C model was 0.53% v/v and errors of the same order of magnitude were obtained at other temperatures (15, 35 and 40°C. And an 2 better than 0.99 was achieved for each validation set. The possibility and accuracy of using the miniature SW-NIR spectrometer and GLSW transfer calibration method for alcohol determination at different temperatures were proven. And the analysis procedure was simple and fast, allowing a strict control of alcohol content in the wine industry.

Plan and reports of coupled irradiation (JRR-3 and JOYO of research reactors) and hot facilities work (WASTEF, JMTR-HL, MMF and FMF). R and D project on irradiation damage management technology for structural materials of long-life nuclear plant

International Nuclear Information System (INIS)

Matsui, Yoshinori; Yamamoto, Masaya; Yoshitake, Tsunemitsu; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ichikawa, Shoichi; Yamagata, Ichiro; Soga, Tomonori; Yonekawa, Minoru; Kitamura, Ryoichi; Miyake, Osamu; Takahashi, Hiroyuki; Ishikawa, Kazuyoshi; Kikuchi, Taiji; Usami, Koji; Endo, Shinya; Ichise, Kenichi; Numata, Masami; Onozawa, Atsushi; Aizawa, Masao; Kusunoki, Tsuyoshi; Nakata, Masahito; Abe, Kazuyuki; Ito, Kazuhiro; Takaya, Shigeru; Nagae, Yuji; Wakai, Eiichi; Aoto, Kazumi

2010-03-01

'R and D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant' was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of 'Evaluation of Irradiation Damage Indicator' in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research and Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency. (author)

Dosimetry of blood irradiator - 2000

International Nuclear Information System (INIS)

Mhatre, Sachin G.V.; Shinde, S.H.; Bhat, R.M.; Rao, Suresh; Sharma, D.N.

2008-01-01

Full text: Blood transfusion to an immunodeficient or immunosuppressed patient has a high risk involved due to occurrence of Transfusion Graft Versus Host Disease (T-GVHD). In order to eliminate this problem, blood is routinely exposed to ionizing radiation (gamma) prior to transfusion. Doses ranging from 15 Gy to 50 Gy can prevent T-GVHD. Aim of the present work was to perform dosimetry of 60 Co Blood Irradiator-2000 developed by Board of Radiation and isotope Technology (BRIT), India; using FBX dosimetric system. Dose-rate measured by FBX dosimeter was intercompared with Fricke dosimeter, which is a Reference Standard dosimeter. Experiments included measurement of dose-rate at the centre of irradiation volume, dose mapping in the central vertical plane within the irradiation volume and measurement of average dose received by blood sample using blood bags filled with FBX dosimeter by simulating actual irradiation conditions. During irradiation, the sample chamber is retracted into a cylindrical source cage, so that the sample is irradiated from all sides uniformly. Blood irradiator-2000 has sample rotation facility for increasing the dose uniformity during irradiation. The performance of this was investigated by measuring the central vertical plane dose profile in stationary state as well in rotation using the sample rotation facility (60 rpm). FBX being an aqueous dosimetric system fills container of irregular shape being irradiated hence can be used to integrate the dose over the volume. Dose-rate measured by FBX dosimeter was intercompared with Fricke dosimeter, which was in good agreement. Average dose-rate at the centre of irradiation volume and within the blood bag was measured by FBX and Fricke dosimeters. It was observed that dose profiles measured by FBX and Fricke dosimeters agreed within ± 2%. Dose uniformity within the irradiation volume was found to reduce from 21% to 17% when the sample rotation facility was used. Thus, it is suggested by the

Improved Correction of IR Loss in Diffuse Shortwave Measurements: An ARM Value-Added Product

Energy Technology Data Exchange (ETDEWEB)

Younkin, K; Long, CN

2003-11-01

Simple single black detector pyranometers, such as the Eppley Precision Spectral Pyranometer (PSP) used by the Atmospheric Radiation Measurement (ARM) Program, are known to lose energy via infrared (IR) emission to the sky. This is especially a problem when making clear-sky diffuse shortwave (SW) measurements, which are inherently of low magnitude and suffer the greatest IR loss. Dutton et al. (2001) proposed a technique using information from collocated pyrgeometers to help compensate for this IR loss. The technique uses an empirically derived relationship between the pyrgeometer detector data (and alternatively the detector data plus the difference between the pyrgeometer case and dome temperatures) and the nighttime pyranometer IR loss data. This relationship is then used to apply a correction to the diffuse SW data during daylight hours. We developed an ARM value-added product (VAP) called the SW DIFF CORR 1DUTT VAP to apply the Dutton et al. correction technique to ARM PSP diffuse SW measurements.

Impacts of spectral nudging on the simulated surface air temperature in summer compared with the selection of shortwave radiation and land surface model physics parameterization in a high-resolution regional atmospheric model

Science.gov (United States)

Park, Jun; Hwang, Seung-On

2017-11-01

The impact of a spectral nudging technique for the dynamical downscaling of the summer surface air temperature in a high-resolution regional atmospheric model is assessed. The performance of this technique is measured by comparing 16 analysis-driven simulation sets of physical parameterization combinations of two shortwave radiation and four land surface model schemes of the model, which are known to be crucial for the simulation of the surface air temperature. It is found that the application of spectral nudging to the outermost domain has a greater impact on the regional climate than any combination of shortwave radiation and land surface model physics schemes. The optimal choice of two model physics parameterizations is helpful for obtaining more realistic spatiotemporal distributions of land surface variables such as the surface air temperature, precipitation, and surface fluxes. However, employing spectral nudging adds more value to the results; the improvement is greater than using sophisticated shortwave radiation and land surface model physical parameterizations. This result indicates that spectral nudging applied to the outermost domain provides a more accurate lateral boundary condition to the innermost domain when forced by analysis data by securing the consistency with large-scale forcing over a regional domain. This consequently indirectly helps two physical parameterizations to produce small-scale features closer to the observed values, leading to a better representation of the surface air temperature in a high-resolution downscaled climate.

Food irradiation: Activities and potentialities

Science.gov (United States)

Doellstaedt, R.; Huebner, G.

After the acceptance of food irradiation up to an overall average dose of 10 kGy recommended by the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food in October 1980, the G.D.R. started a programme for the development of techniques for food irradiation. A special onion irradiator was designed and built as a pilot plant for studying technological and economic parameters of the irradiation of onions. The new principle of bulk-cargo irradiation allows the integration of this technology into the usual harvest technology for onions on the way from field to storage. Scientific and applied research work has been carried out in the past 3 yr on the irradiation of spices, potatoes, eviscerated chicken, animal feeds, fodder yeast, drugs and vaccines. In connection with the irradiation of eviscerated chicken, fodder yeast and animal feeds the basis of an antisalmonella programme has been discussed. Germ-count-reduced spices were employed for the production of test charges of preserves and tinned products. The results have led to the decision to design and build a new multipurpose irradiator for food irradiation. In order to cover the legal aspects of food irradiation the Ministry of Health issued regulations concerning the recommendation of irradiated food in the G.D.R.

Relationship between swelling and irradiation creep in cold worked PCA stainless steel to 178 DPA at∼400 degrees C

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1993-01-01

At 178 dpa and ∼400 degrees C, the irradiation creep behavior of 20% cold-worked PCA has become dominated by the creep disappearance phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however

Dosimetric survey in industrial irradiators and dosimetric systems calibration

International Nuclear Information System (INIS)

Grossi, Pablo Andrade; Correa, Ricardo Ferracini; Oliveira, Paulo Marcio C. de

2005-01-01

The work seeks the collecting of dose rate points for irradiation research plants and calibration of commercial dosimeters, using dosimeters standard references. Using the obtained data is possible to determine the absorbed doses in any point of an irradiation room, assuring the value of absorbed dose in the irradiated product, with the use of the commercial dosimeters. The commercial dosimeters used in this work are polymethylmethacrylate (PMMA), and the reference dosimeters used are Fricke's solution. Among the advantages of the accomplishment of this work, it can stand out the quality assurance of the services rendered by Centro de Desenvolvimento da Tecnologia Nuclear to their customers and to the society, in the purpose of optimization of exposition time of the irradiated products, in way to guarantee the absorbed doses in each irradiated material with a good precision

Cell Morphology Change by the Ultraviolet Ray Irradiation

International Nuclear Information System (INIS)

Park, Myung Joo; Matuo, Yoichirou; Akiyama, Yoko; Izumi, Yoshinobu; Nishijima, Shigehiro

2009-01-01

The effect of low doses of ultraviolet (UV) irradiation on morphology changes of cell has been studied based on the observation of the cell length. It was shown that UV-irradiated cell has different behavior in comparison with nonirradiated cell. From the histogram of cell-length distribution, it was confirmed that cell cycle of non irradiated cell was 28 hours, and that cell cycle of irradiated cell with dose of 20 Jm -2 was delayed (39 hours), while irradiated cell with 40 Jm -2 and 60 Jm -2 did not divide and kept growing continuously. It was supposed that in case of 20 Jm -2 of irradiation dose, the cell cycle was delayed because the checkpoint worked in order to repair DNA damage induced by generation of pyrimidine dimer, reactive oxygen species and so on. It was also supposed that in case of 40 Jm -2 and 60 Jm -2 of irradiation dose, overgrowth was induced because the checkpoint was not worked well. The morphology of overgrown cell was similar to that of normally senescent cell. Therefore, it was considered that cell senescence was accelerated by UV irradiation with irradiation doses of 40 Jm -2 and 60 Jm -2

Economics of gamma irradiation processing

International Nuclear Information System (INIS)

Tani, Toshio

1980-01-01

The gamma-ray irradiation business started at the Takasaki Laboratory of Japan Atomic Energy Research Institute. The irradiation facilities were constructed thereafter at various sites. The facilities must accept various types of irradiation, and must be constructed as multi-purpose facilities. The cost of irradiation consists of the cost of gamma sources, construction expense, personnel expense, management expense, and bank interest. Most of the expenses are considered to be fixed expense, and the amount of irradiation treatment decides the original costs of work. The relation between the irradiation dose and the construction expense shows the larger facility is more economical. The increase of amount of treatment reduces the original cost. The utilization efficiency becomes important when the amount of treatment and the source intensity exceed some values. The principal subjects of gamma-ray irradiation business are the sterilization of medical tools and foods for aseptic animals, the improvement of quality of plastic goods, and the irradiation of foods. Among them, the most important subject is the sterilization of medical tools. The cost of gamma irradiation per m 3 in still more expensive than that by ethylene oxide gas sterilization. However, the demand of gamma-ray irradiation is increasing. For the improvement of quality of plastic goods, electron irradiation is more favourable than the gamma irradiation. In near future, the economical balance of gamma irradiation can be achieved. (Kato, T.)

The post-irradiated examination of CANDU type fuel irradiated in the Institute for Nuclear Research TRIGA reactor

International Nuclear Information System (INIS)

Tuturici, I.L.; Parvan, M.; Dobrin, R.; Popov, M.; Radulescu, R.; Toma, V.

1995-01-01

This post-irradiation examination work has been done under the Research Contract No. 7756/RB, concluded between the International Atomic Energy Agency and the Institute for Nuclear Research. The paper contains a general description of the INR post-irradiation facility and methods and the relevant post-irradiation examination results obtained from an irradiated experimental CANDU type fuel element designed, manufactured and tested by INR in a power ramp test in the 100 kW Pressurised Water Irradiation Loop of the TRIGA 14 MW(th) Reactor. The irradiation experiment consisted in testing an assembly of six fuel elements, designed to reach a bumup of ∼ 200 MWh/kgU, with typical CANDU linear power and ramp rate. (author)

A novel method for surface defect inspection of optic cable with short-wave infrared illuminance

Science.gov (United States)

Chen, Xiaohong; Liu, Ning; You, Bo; Xiao, Bin

2016-07-01

Intelligent on-line detection of cable quality is a crucial issue in optic cable factory, and defects on the surface of optic cable can dramatically depress cable grade. Manual inspection in optic cable quality cannot catch up with the development of optic cable industry due to its low detection efficiency and huge human cost. Therefore, real-time is highly demanded by industry in order to replace the subjective and repetitive process of manual inspection. For this reason, automatic cable defect inspection has been a trend. In this paper, a novel method for surface defect inspection of optic cable with short-wave infrared illuminance is presented. The special condition of short-wave infrared cannot only provide illumination compensation for the weak illumination environment, but also can avoid the problem of exposure when using visible light illuminance, which affects the accuracy of inspection algorithm. A series of image processing algorithms are set up to analyze cable image for the verification of real-time and veracity of the detection method. Unlike some existing detection algorithms which concentrate on the characteristics of defects with an active search way, the proposed method removes the non-defective areas of the image passively at the same time of image processing, which reduces a large amount of computation. OTSU algorithm is used to convert the gray image to the binary image. Furthermore, a threshold window is designed to eliminate the fake defects, and the threshold represents the considered minimum size of defects ε . Besides, a new regional suppression method is proposed to deal with the edge burrs of the cable, which shows the superior performance compared with that of Open-Close operation of mathematical morphological in the boundary processing. Experimental results of 10,000 samples show that the rates of miss detection and false detection are 2.35% and 0.78% respectively when ε equals to 0.5 mm, and the average processing period of one frame

Statistical analysis of the irradiation process of various products in the industrial irradiator JS-6500

International Nuclear Information System (INIS)

Naquid G, C.

2003-01-01

In this work the methodology for the control of the irradiation service applied to disposable products of medical use, foods, medications, cosmetics and several to different dose in the Gamma Irradiation Plant, with radiation of Cobalt 60, by means of the Graphs of Quality Control by Variables. These they are used to check if the irradiation process has been carried out appropriately, or well, if the variations surpass the established limits in the one that influences some another factor. (Author)

Rheological changes in irradiated chicken eggs

Science.gov (United States)

Ferreira, Lúcia F. S.; Del Mastro, Nélida L.

1998-06-01

Pathogenic bacteria may cause foodborne illnesses. Humans may introduce pathogens into foods during production, processing, distribution and or preparation. Some of these microorganisms are able to survive conventional preservation treatments. Heat pasteurization, which is a well established and satisfactory means of decontamination/disinfection of liquid foods, cannot efficiently achieve a similar objective for solid foods. Extensive work carried out worldwide has shown that irradiation is efficient in eradicating foodborne pathogens like Salmonella spp. that can contaminate poultry products. In this work Co-60 gamma irradiation was applied to samples of industrial powder white, yolk and whole egg at doses between 0 and 25 kGy. Samples were rehydrated and the viscosity measured in a Brookfield viscosimeter, model DV III at 5, 15 and 25°C. The rheological behaviour among the various kinds of samples were markedly different. Irradiation with doses up to 5 kGy, known to reduced bacterial contamination to non-detectable levels, showed almost no variation of viscosity of irradiated egg white samples. On the other hand, whole or yolk egg samples showed some changes in rheological properties depending on the dose level, showing the predominance of whether polimerization or degradation as a result of the irradiation. Additionally, irradiation of yolk egg powder reduced yolk color as a function of the irradiation exposure implemented. The importance of these results are discussed in terms of possible industrial applications.

Rheological changes in irradiated chicken eggs

International Nuclear Information System (INIS)

Ferreira, Lucia F. S.; Del Mastro, Nelida L.

1998-01-01

Pathogenic bacteria may cause foodborne illnesses. Humans may introduce pathogens into foods during production, processing, distribution and or preparation. Some of these microorganisms are able to survive conventional preservation treatments. Heat pasteurization, which is a well established and satisfactory means of decontamination/disinfection of liquid foods, cannot efficiently achieve a similar objective for solid foods. Extensive work carried out worldwide has shown that irradiation is efficient in eradicating foodborne pathogens like Salmonella spp. that can contaminate poultry products. In this work Co-60 gamma irradiation was applied to samples of industrial powder white, yolk and whole egg at doses between 0 and 25 kGy. Samples were rehydrated and the viscosity measured in a Brookfield viscosimeter, model DV III at 5, 15 and 25 degree sign C. The rheological behaviour among the various kinds of samples were markedly different. Irradiation with doses up to 5 kGy, known to reduced bacterial contamination to non-detectable levels, showed almost no variation of viscosity of irradiated egg white samples. On the other hand, whole or yolk egg samples showed some changes in rheological properties depending on the dose level, showing the predominance of whether polimerization or degradation as a result of the irradiation. Additionally, irradiation of yolk egg powder reduced yolk color as a function of the irradiation exposure implemented. The importance of these results are discussed in terms of possible industrial applications

Effect of irradiation temperature on microstructural changes in self-ion irradiated austenitic stainless steel

Science.gov (United States)

Jin, Hyung-Ha; Ko, Eunsol; Lim, Sangyeob; Kwon, Junhyun; Shin, Chansun

2017-09-01

We investigated the microstructural and hardness changes in austenitic stainless steel after Fe ion irradiation at 400, 300, and 200 °C using transmission electron microscopy (TEM) and nanoindentation. The size of the Frank loops increased and the density decreased with increasing irradiation temperature. Radiation-induced segregation (RIS) was detected across high-angle grain boundaries, and the degree of RIS increases with increasing irradiation temperature. Ni-Si clusters were observed using high-resolution TEM in the sample irradiated at 400 °C. The results of this work are compared with the literature data of self-ion and proton irradiation at comparable temperatures and damage levels on stainless steels with a similar material composition with this study. Despite the differences in dose rate, alloy composition and incident ion energy, the irradiation temperature dependence of RIS and the size and density of radiation defects followed the same trends, and were very comparable in magnitude.

Irradiation, annealing, and reirradiation research in the ORNL heavy-section steel irradiation program

International Nuclear Information System (INIS)

Nanstad, R.K.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.

1997-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPV) is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results from work performed as part of the Heavy-Section Steel Irradiation (HSSI) Program managed by Oak Ridge National Laboratory (ORNL) for the U.S. Nuclear Regulatory Commission. The HSSI Program focuses on annealing and re-embrittlement response of materials which are representative of those in commercial RPVs and which are considered to be radiation-sensitive. Experimental studies include (1) the annealing of materials in the existing inventory of previously irradiated materials, (2) reirradiation of previously irradiated/annealed materials in a collaborative program with the University of California, Santa Barbara (UCSB), (3) irradiation/annealing/reirradiation of U.S. and Russian materials in a cooperative program with the Russian Research Center-Kurchatov Institute (RRC-KI), (4) the design and fabrication of an irradiation/anneal/reirradiation capsule and facility for operation at the University of Michigan Ford Reactor, (5) the investigation of potential for irradiation-and/or thermal-induced temper embrittlement in heat-affected zones (HAZs) of RPV steels due to phosphorous segregation at grain boundaries, and (6) investigation of the relationship between Charpy impact toughness and fracture toughness under all conditions of irradiation, annealing, and reirradiation

ACPSEM ROSG TBE working group recommendations for quality assurance in total body electron irradiation

International Nuclear Information System (INIS)

Nelligan, Raelene; Baldwin, Zoe; Ostwald, Trish; Tran, Thi; Bailey, Michael

2015-01-01

The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Radiation Oncology Specialty Group (ROSG) formed a series of working groups in 2011 to develop recommendations for guidance of radiation oncology medical physics practice within the Australasian setting. These recommendations are intended to provide guidance for safe work practices and a suitable level of quality control without detailed work instructions. It is the responsibility of the medical physicist to ensure that locally available equipment and procedures are sufficiently sensitive to establish compliance to these recommendations. The recommendations are endorsed by the ROSG, and have been subject to independent expert reviews. For the Australian readers, these recommendations should be read in conjunction with the Tripartite Radiation Oncology Reform Implementation Committee Quality Working Group: Radiation Oncology Practice Standards (2011), and Radiation Oncology Practice Standards Supplementary Guide (2011). This publication presents the recommendations of the ACPSEM ROSG Total Body Electron Irradiation Working Group and has been developed in alignment with other international associations. However, these recommendations should be read in conjunction with relevant national, state or territory legislation and local requirements, which take precedence over the ACPSEM recommendations. It is hoped that the users of this and other ACPSEM recommendations will contribute to the development of future versions through the Radiation Oncology Specialty Group of the ACPSEM. This document serves as a guideline for calibration and quality assurance of equipment used for TBE in Australasia.

Vinca irradiator

International Nuclear Information System (INIS)

Eymery, R.

1976-10-01

The development programme of the VINCA radiosterilisation centre involves plans for an irradiator capable of working in several ways. Discontinuous operation. The irradiator is loaded for a certain period then runs automatically until the moment of unloading. This method is suitable as long as the treatment capacity is relatively small. Continuous operation with permanent batch loading and unloading carried out either manually or automatically (by means of equipment to be installed later). Otherwise the design of the apparatus is highly conventional. The source is a vertical panel submersible in a pool. The conveyor is of the 'bucket' type, with 4 tiers to each bucket. The batches pass successively through all possible irradiation positions. Transfert into and out of the cell take place through a maze, which also provides access to the cell when the sources are in storage at the bottom of the pool [fr

Irradiation induced effects in zirconium (A review)

International Nuclear Information System (INIS)

Madden, P.K.

1975-06-01

Irradiation creep in zirconium and its alloys is comprehensively discussed. The main theories are outlined and the gaps between them and the observed creep behaviour, indicated. Although irradiation induced point defects play an important role, effects due to irradiation induced dislocation loops seem insignificant. The experimental results suggest that microstructural variations due to prior cold-working or hydrogen injection perturb the irradiation growth and the irradiation creep of zircaloy. Further investigations into these areas are required. One disadvantage of creep experiments lies in their duration. The possibility of accelerated experiments using ion implantation or electron irradiation is examined in the final section, and its possible advantages and disadvantages are outlined. (author)

[Determination of fat, protein and DM in raw milk by portable short-wave near infrared spectrometer].

Science.gov (United States)

Li, Xiao-yun; Wang, Jia-hua; Huang, Ya-wei; Han, Dong-hai

2011-03-01

Near infrared diffuse reflectance spectroscopy calibrations of fat, protein and DM in raw milk were studied with partial least-squares (PLS) regression using portable short-wave near infrared spectrometer. The results indicated that good calibrations of fat and DM were found, the correlation coefficients were all 0.98, the RMSEC were 0.187 and 0.217, RMSEP were 0.187 and 0.296, the RPDs were 5.02 and 3.20 respectively; the calibration of protein needed to be improved but can be used for practice, the correlation coefficient was 0.95, RMSEC was 0.105, RMSEP was 0.120, and RPD was 2.60. Furthermore, the measuring accuracy was improved by analyzing the correction relation of fat and DM in raw milk This study will probably provide a new on-site method for nondestructive and rapid measurement of milk.

Relation between seasonally detrended shortwave infrared reflectance data and land surface moisture in semi-arid Sahel

DEFF Research Database (Denmark)

Olsen, Jørgen Lundegaard; Ceccato, Pietro; Proud, Simon Richard

2013-01-01

in vegetation moisture status, and is compared to detrended time series of the Normalized Difference Vegetation Index (NDVI). It was found that when plant available water is low, the SIWSI anomalies increase over time, while the NDVI anomalies decrease over time, but less systematically. Therefore SIWSI may......In the Sudano-Sahelian areas of Africa droughts can have serious impacts on natural resources, and therefore land surface moisture is an important factor. Insufficient conventional sites for monitoring land surface moisture make the use of Earth Observation data for this purpose a key issue...... Second Generation (MSG) satellite. We focused on responses in surface reflectance to soil- and surface moisture for bare soil and early to mid- growing season. A method for implementing detrended time series of the Shortwave Infrared Water Stress Index (SIWSI) is examined for detecting variations...

Correlation of fracture toughness with tensile properties for irradiated 20% cold-worked 316 stainless steel

International Nuclear Information System (INIS)

Hamilton, M.L.; Garner, F.A.; Wolfer, W.G.

1983-08-01

A correlation has been developed which allows an estimate to be made of the toughness of austenitic alloys using more easily obtained tensile data. Tensile properties measured on 20% cold-worked AISI 316 specimens made from ducts and cladding irradiated in EBR-II were used to predict values for the plane strain fracture toughness according to a model originally developed by Krafft. Some microstructural examination is required to determine a parameter designated as the process zone size. In contrast to the frequently employed Hahn-Rosenfeld model, this model gives results which agree with recent experimental determinations of toughness performed in the transgranular failure regime

Influence of photo- and chromatic acclimation on pigment composition in the sea

Directory of Open Access Journals (Sweden)

Roman Majchrowski

2000-06-01

Full Text Available The aim of this work was to find statistical relationships between the concentrations of accessory pigments in natural populations of marine phytoplankton and the absolute levels and spectral distributions of underwater irradiance. To this end, empirical data sets from some 600 stations in different parts of the seas and oceans were analysed. These data were obtained from the authors' own research and from the Internet's bio-optical data base. They included the vertical distributions of the concentrations of various pigments (identified chromatographically and the vertical and spectral distributions of the underwater irradiance measured in situ or determined indirectly from bio-optical models. The analysis covered a total of some 4000 points illustrating the dependence of pigment concentration on underwater irradiance characteristics, corresponding to different depths in the sea. The analysis showed that the factor governing the occurrence of photoprotecting carotenoids (PPC is short-wave radiation λ a concentration and the magnitude of the absorbed radiative energy per unit mass of chlorophyll a from the spectral interval λ z = 60 m (or less near the surface to account for vertical mixing. This absorbed short-wave radiation (λ *(z. Analysis of the relationships between the concentrations of particular photosynthetic pigments (PSP, i.e. chlorophyll b, chlorophyll c, photosynthetic carotenoids (PSC, and the underwater irradiance characteristics indicated that these concentrations were only slightly dependent on the absolute level of irradiance E0(λ, but that they depended strongly on the relative spectral distribution of this irradiance f(λ= E0(λ/PAR0. The relevant approximate statistical relationships between the relative concentrations of particular PSP and the function of spectral fitting Fj, averaged in the layer Δz, were derived. Certain statistical relationships between the pigment composition of the phytoplankton and the irradiance

Scanner and irradiation: optimization of protocols

International Nuclear Information System (INIS)

Duchemin, J.; Martine-Rollet, B.; Lienart, S.; Mobailly, M.; Florin, J.P.; Beregi, J.P.; Puech, N.

2006-01-01

The irradiation of the patient or the personnel increased with the arrival of the multi-detector scanners. The objective of this work is to realize a didactic poster to inform and make sensitive on the irradiation with scan so that to propose solutions of protection. (N.C.)

Educative campaign about information on irradiated foods

International Nuclear Information System (INIS)

Luna C, P.C.

1991-07-01

The irradiation of foods is accepted by international agencies (FAO, OMS) like a healthy and effective technology at the moment the irradiated foods are marketed easily in many countries, however in other countries exist several factors that affect the practical application of this process. In this work is planned about an educational campaign about the irradiation process directed to the consumers. (Author)

Irradiation effects on reactor structural materials. Semi-annual progress report, August 1974--February 1975

International Nuclear Information System (INIS)

Claudson, T.T.

1975-03-01

Data are reported on: effects of cold work on creep-fatigue of irradiated 304 and 316 stainless steel (ss); swelling of 304 and 316 ss irradiated with protons and fast neutrons; effects of hold time on fatigue crack propagation in neutron-irradiated 20 percent cold-worked 316 ss; radiation resistance of 0.03 percent Cu A533-B steel; microstructure of irradiated Inconel 718, Incoloy 800, PH13-8Mo, Mo, and Nb; dose dependence of 2.8-MeV Ni + ion damage (swelling) in Ni; notch ductility and strength of 316 ss submerged arc weld deposits; effects of microstructure of 316 ss on its irradiation response; in-reactor deformation of 20 percent cold-worked 316 ss; microstructure of HFIR-irradiated 316 ss; void microstructures of V bombarded by 46-MeV Ni 6+ ions (with and without preinjected helium) or 7.5-MeV Ta 3+ ions; swelling of Mo, Mo--0.5 Ti, Nb, Nb--1 Zr, W, and W--25 Re after fast neutron irradiation; swelling of V ion-irradiated Mo; creep of 20 percent cold-worked 316 ss at 850, 1000, and 1100 0 F; effects of fast neutrons on mechanical properties of 20 percent cold-worked 316 ss; notch effects in tensile behavior of irradiated, annealed 304 ss (EBR-II duct thimbles); equations for thermal creep in pressurized tubes of 20 percent cold-worked 316 ss; irradiation creep in cold-worked 316 ss; helium production cross sections in neutron-irradiated elements; and radiation effects on various alloys. (U.S.)

Photo-induced antimicrobial and DNA cleavage studies of ...

Indian Academy of Sciences (India)

of quinoline derivatives has led to their successful use in different fields ... cally produces cell damage that inactivates the microor- ... bioactivity against bacteria upon UV irradiation. The ... were visualized by shortwave UV light and iodine.

Results of work in the hot cells of Laboratory Testing Materials Irradiated Areva of Carina project for the expansion of the database of mechanical characteristics of fractures in materials of RPV German irradiated

International Nuclear Information System (INIS)

Barthelmes, J.; Schabel, H.; Hein, H.; Kein, E.; Eiselt, C.

2013-01-01

In the frame of the already completed research projects CARINA and its predecessor CARISMA a data base was created for pre-irradiated original RPV steels of German PWRs which allowed to examine the consequences if the Master Curve (T 0 ) approach instead of the RT N OT concept is applied to the RPV safety assessment. Furthermore in CARINA different irradiation conditions with respect to the accumulated neutron fluences and specific impact parameters were investigated. Besides a brief introduction of the CARINA project and an overview of the main results an overview on the requirements of the hot laboratory work in terms of specimen manufacturing and material testing is given and examples for realization are shown. (Author)

The PHENIX experimental irradiation program

International Nuclear Information System (INIS)

Michel, P.; Courcon, P.; Coulon, P.

1985-03-01

The PHENIX experimental irradiation program represents a substancial volume of work. For example, more than forty experiments were in the core during the 33rd PHENIX irradiation cycle at the end of 1984. This program ensures the implementation, optimization and qualification of new solutions for the future developpment of French LMFBRs in three significant areas: fissile, fertile and absorber elements

Structural integrity of stainless steel components exposed to neutron irradiation. Change in failure strength of cracked components due to cold working

International Nuclear Information System (INIS)

Kamaya, Masayuki; Hojo, Tomohiro; Mochizuki, Masahito

2015-01-01

Load carrying capacity of austenitic stainless steel component is increased due to hardening caused by neutron irradiation if no crack is included in the component. On the other hand, if a crack is initiated in the reactor components, the hardening may decrease the load carrying capacity due to reduction in fracture toughness. In this paper, in order to develop a failure assessment procedure of irradiated cracked components, characteristics of change in failure strength of stainless steels due to cold working were investigated. It was experimentally shown that the proof and tensile strengths were increased by the cold working, whereas the fracture toughness was decreased. The fracture strengths of a cylinder with a circumferential surface crack were analyzed using the obtained material properties. Although the cold working altered the failure mode from plastic collapse to the unsteady ductile crack growth, it did not reduce failure strengths even if 50% cold working was applied. The increase in failure strength was caused not only by increase in flow stress but also by reduction in J-integral value, which was brought by the change in stress-strain curve. It was shown that the failure strength of the hardened stainless steel components could be derived by the two-parameter method, in which the change in material properties could be reasonably considered. (author)

Development of system for product tracking and data acquisition of data irradiation process in large gamma irradiators

International Nuclear Information System (INIS)

Soares, Jose Roberto

2010-01-01

The sterilization of medical care products using ionizing radiation is a consolidated technique. In Brazil there are in operation gamma irradiators with capacity between 0.37 PBq (10kCi) 185 PBq (5 MCi) using radioisotopes 60 Co as radiation source. The developed work provides an accurate control and a data acquisition for the application of Good Manufacturing Practices during all phases of an irradiation process, required by the standards of ANVISA, ISO and IAEA technical recommendations for the treatment of foods and medical products. All the steps involved in the irradiation treatment are mapped into process flow (work flow), where each agent (participant) has its systematized tasks. The data acquisition process, monitoring and control, are based on a set of tools (free software licenses) integrated by a network of efficient communication, including the use of Web resources. Using the Gamma Irradiator Multipurpose IPEN/CNEN/USP all the development was performed to be applied in irradiators facilities operating in industrial scale. The system enables a complete traceability of the process, in real time, for any participant and also the storage of the corresponding records to be audited. (author)

Development of system for product tracking and data acquisition of data irradiation process in large gamma irradiators

International Nuclear Information System (INIS)

Soares, Jose R.; Rela, Paulo R.; Costa, Fabio E.

2011-01-01

The sterilization of medical care products using ionizing radiation is a consolidated technique. In Brazil there are in operation gamma irradiators with capacity between 0.37 PBq (10kCi) 185 PBq (5 MCi) using radioisotopes 60 Co as radiation source. The developed work provides an accurate control and data acquisition for the application of good manufacturing practices during all phases of an irradiation process, required by the standards of ANVISA, technical ISO and IAEA recommendations for the treatment of foods and medical products. All the steps involved in the irradiation treatment are mapped into process flow (work flow), where each agent (participant) has its systematized tasks. The automatic data process acquisition using wireless ZigBee technology, monitoring and control, are based on a set of tools (free software licenses) integrated by a network of efficient communication, including the use of Web resources. Using the Gamma Irradiator Multipurpose IPEN/CNEN-SP all the development was performed to be applied in irradiators' facilities operating in industrial scale. The system enables a complete traceability of the process, in real time, for any participant and also the storage of the corresponding records to be audited. (author)

Development of system for product tracking and data acquisition of data irradiation process in large gamma irradiators

Energy Technology Data Exchange (ETDEWEB)

Soares, Jose R., E-mail: joseroberto.soares@mackenzie.br [Universidade Presbiteriana Mackenzie. Escola de Engenharia. Sao Paulo, SP (Brazil); Rela, Paulo R.; Costa, Fabio E., E-mail: prela@ipen.br, E-mail: fecosta@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

The sterilization of medical care products using ionizing radiation is a consolidated technique. In Brazil there are in operation gamma irradiators with capacity between 0.37 PBq (10kCi) 185 PBq (5 MCi) using radioisotopes {sup 60}Co as radiation source. The developed work provides an accurate control and data acquisition for the application of good manufacturing practices during all phases of an irradiation process, required by the standards of ANVISA, technical ISO and IAEA recommendations for the treatment of foods and medical products. All the steps involved in the irradiation treatment are mapped into process flow (work flow), where each agent (participant) has its systematized tasks. The automatic data process acquisition using wireless ZigBee technology, monitoring and control, are based on a set of tools (free software licenses) integrated by a network of efficient communication, including the use of Web resources. Using the Gamma Irradiator Multipurpose IPEN/CNEN-SP all the development was performed to be applied in irradiators' facilities operating in industrial scale. The system enables a complete traceability of the process, in real time, for any participant and also the storage of the corresponding records to be audited. (author)

Irradiation Microstructure of Austenitic Steels and Cast Steels Irradiated in the BOR-60 Reactor at 320°C

Science.gov (United States)

Yang, Yong; Chen, Yiren; Huang, Yina; Allen, Todd; Rao, Appajosula

Reactor internal components are subjected to neutron irradiation in light water reactors, and with the aging of nuclear power plants around the world, irradiation-induced material degradations are of concern for reactor internals. Irradiation-induced defects resulting from displacement damage are critical for understanding degradation in structural materials. In the present work, microstructural changes due to irradiation in austenitic stainless steels and cast steels were characterized using transmission electron microscopy. The specimens were irradiated in the BOR-60 reactor, a fast breeder reactor, up to 40 dpa at 320°C. The dose rate was approximately 9.4x10-7 dpa/s. Void swelling and irradiation defects were analyzed for these specimens. A high density of faulted loops dominated the irradiated-altered microstructures. Along with previous TEM results, a dose dependence of the defect structure was established at 320°C.

The effect of irradiation and irradiation temperature on the fracture toughness of cold-worked Zr-2.5 wt percent Nb

International Nuclear Information System (INIS)

Simpson, L.A.; Ellis, R.B.; Stark, D.J.; Shillinglaw, A.J.

1984-09-01

The use of fracture mechanics methods and small specimens to assess the effect of metallurgical variables on fracture toughness and critical crack length in reactor pressure tubes is reviewed. Fracture toughness tests on specimens irradiated in the NRU research reactor at 260 degrees C are described and compared with results from a previous irradiation in the WR-1 research reactor at 350 degrees C. The J-resistance curve is used as the measure of fracture toughness, and is shown to be very sensitive to the metallurgical state. The lower irradiation temperature (260 degrees C), characteristic of the operating temperature range for power reactors, has a significant effect on fracture toughness. Circumferential hydrides also have an effect. Estimates of critical crack length are made using the J-resistance data, and are seen to slightly underestimate the actual critical crack length as determined in full-scale burst tests. This conservatism is not large enough to impose a significant penalty in design applications

Acceptance of irradiated food: an education issue

International Nuclear Information System (INIS)

Modanez, Leila

2012-01-01

The commercial use of irradiated food technology in Brazil has a slow growing due to misinterpretation by most Brazilian consumers, who have been mislead by wrong ideas about the meaning of what is nuclear energy. Researches indicate that consumers have difficult in accepting such a technology due to the confusion between the terms irradiation and radioactivity, which are often related to health risks. When properly informed about the process, its purpose and the benefits offered by food irradiation technology, most consumers react positively. Therefore, this work aims to: first, to evaluate the acceptance of irradiated foods by Brazilian consumers; second, to verify the teaching at school about the food irradiation process; third, to analyze the Brazilian school curriculum from elementary school to high school, regarding nuclear energy applications; then, to compare the content taught in Brazil with the content covered in other surveyed countries, such as France, United States, and China. The methodology of this study consisted of a systematic survey of the specific literature, and a questionnaire to verify the acceptance of irradiated food by Brazilian consumers. According to the researched bibliography, it was clear the recommendation of an early school education about the usage of nuclear energy, more specifically, food irradiation. Such a recommendation is due to the fact that the consulted costumers, in Brazil and other countries mentioned in this work, do not clearly understand the full benefits of irradiated food. Hence, education is fundamental for the acceptance of new technologies by consumers, as it is the case with irradiated food. (author)

Surface modification of multilayer graphene using Ga ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Shao, Ying; Ge, Daohan; Ren, Naifei [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yang, Qizhi [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State key laboratory of Robotics, Chinese Academy of Sciences, Shengyang 110000 (China)

2015-04-28

The effect of Ga ion irradiation intensity on the surface of multilayer graphene was examined. Using Raman spectroscopy, we determined that the irradiation caused defects in the crystal structure of graphene. The density of defects increased with the increase in dwell times. Furthermore, the strain induced by the irradiation changed the crystallite size and the distance between defects. These defects had the effect of doping the multilayer graphene and increasing its work function. The increase in work function was determined using contact potential difference measurements. The surface morphology of the multilayer graphene changed following irradiation as determined by atomic force microscopy. Additionally, the adhesion between the atomic force microscopy tip and sample increased further indicating that the irradiation had caused surface modification, important for devices that incorporate graphene.

Fully portable blood irradiator

International Nuclear Information System (INIS)

Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

1980-01-01

A fully portable blood irradiator was developed using the beta emitter thulium-170 as the radiation source and vitreous carbon as the body of the irradiator, matrix for isotope encapsulation, and blood interface material. These units were placed in exteriorized arteriovenous shunts in goats, sheep, and dogs and the effects on circulating lymphocytes and on skin allograft retention times measured. The present work extends these studies by establishing baseline data for skin graft rejection times in untreated animals

The Codex standard and code for irradiated foods

International Nuclear Information System (INIS)

Erwin, L.

1985-01-01

A brief background on the work by the Codex Alimentarius Commission on irradiated foods is given. An Australian model food standard for irradiated foods, based on the Codex standard, is being developed

Nitrogen deficiency detection using reflected shortwave radiation from irrigated corn canopies

International Nuclear Information System (INIS)

Blackmer, T.M.; Schepers, J.S.; Varvel, G.E.; Walter-Shea, E.A.

1996-01-01

Techniques that measure the N status of corn (Zea mays L.) can aid in management decisions that have economic and environmental implications. This study was conducted to identify reflected electromagnetic wavelengths most sensitive to detecting N deficiencies in a corn canopy with the possibility for use as a management tool. Reflected shortwave radiation was measured from an irrigated corn N response trial with four hybrids and five N rates at 0, 40, 80, 120, and 160 kg N ha -1 in 1992 and 0, 50, 100, 150, and 200 kg N ha -1 in 1993. A portable spectroradiometer was used to measure reflected radiation (400-1100 nm in 1992, 350-1050 nm in 1993) from corn canopies at approximately the R5 growth stage. Regression analyses revealed that reflected radiation near 550 and 710 nm was superior to reflected radiation near 450 or 650 nm for detecting N deficiencies. The ratio of light reflectance between 550 and 600 nm to light reflectance between 800 and 900 nm also provided sensitive detection of N stress. In 1993, an inexpensive photometric cell, which has peak sensitivity to light centered at 550 nm, was also used to measure reflected radiation from a corn canopy. Photometric cell readings correlated with relative grain yield (P < 0.001, r 2 = 0.74), but more research will be required to develop procedures to account for varying daylight conditions. These results provide information needed for the development of variable-rate fertilizer N application technology. (author)

Irradiation creep experiments on fusion reactor candidate structural materials

International Nuclear Information System (INIS)

Hausen, H.; Cundy, M.R.; Schuele, W.

1991-01-01

Irradiation creep rates were determined for annealed and cold-worked AMCR- and 316-type steel alloys in the high flux reactor at Petten, for various irradiation temperatures, stresses and for neutron doses up to 4 dpa. Primary creep elongations were found in all annealed materials. A negative creep elongation was found in cold-worked materials for stresses equal to or below about 100 MPa. An increase of the negative creep elongation is found for decreasing irradiation temperatures and decreasing applied stresses. The stress exponent of the irradiation creep rate in annealed and cold-worked AMCR alloys is n = 1.85 and n = 1.1, respectively. The creep rates of cold-worked AMCR alloys are almost temperature independent over the range investigated (573-693 K). The results obtained in the HFR at Petten are compared with those obtained in ORR and EBR II. The smallest creep rates are found for cold-worked materials of AMCR- and US-PCA-type at Petten which are about a factor two smaller than the creep rates obtained of US-316 at Petten or for US-PCA at ORR or for 316L at EBR II. The scatter band factor for US-PCA, 316L, US-316 irradiated in ORR and EBR II is about 1.5 after a temperature and damage rate normalization

Compositional Variations in Sands of the Bagnold Dunes, Gale Crater, Mars, from Visible-Shortwave Infrared Spectroscopy and Comparison to Ground-Truth from the Curiosity Rover

OpenAIRE

Lapotre, M. G. A.; Ehlmann, B. L.; Minson, S. E.; Arvidson, R. E.; Ayoub, F.; Fraeman, A. A.; Ewing, R. C.; Bridges, N. T.

2017-01-01

During its ascent up Mount Sharp, the Mars Science Laboratory Curiosity rover traversed the Bagnold Dune Field. We model sand modal mineralogy and grain size at four locations near the rover traverse, using orbital shortwave infrared single-scattering albedo spectra and a Markov chain Monte Carlo implementation of Hapke's radiative transfer theory to fully constrain uncertainties and permitted solutions. These predictions, evaluated against in situ measurements at one site from the Curiosity ...

Food irradiation, profits and limitations

International Nuclear Information System (INIS)

Luna C, P.C.

1992-05-01

The utility of the irradiation to overcome diverse problems of lost nutritious, it has been demonstrated in multiple investigation works, that its have confirmed the value and the inoculation of the irradiated foods. The quantity of energy applied to each food, is in function of the wanted effect. In this document a guide with respect to the practical application and the utility of the irradiation process in different foods, as well as the suggested dose average is shown. Among the limitations of the use of this technology, its are the costs and not being able to apply it to some fresh foods. (Author)

Implantation of total body irradiation in radiotherapy

International Nuclear Information System (INIS)

Habitzreuter, Angela Beatriz

2010-01-01

Before implementing a treatment technique, the characteristics of the beam under irradiation conditions must be well acknowledged and studied. Each one of the parameters used to calculate the dose has to be measured and validated before its utilization in clinical practice. This is particularly necessary when dealing with special techniques. In this work, all necessary parameters and measurements are described for the total body irradiation implementation in facilities designed for conventional treatments that make use of unconventional geometries to generate desired enlarged field sizes. Furthermore, this work presents commissioning data of this modality at Hospital das Clinicas of Sao Paulo using comparison of three detectors types for measurements of entrance dose during total body irradiation treatment. (author)

The electron irradiation effects in different structures of diodes

International Nuclear Information System (INIS)

Li Quanfen; Wang Jiaxu

1993-01-01

This paper describes the different electron irradiation effects in different structures of diodes and the different results produced by different irradiation ways. From this work, we can know how to choose proper manufacture arts and comprehensive factors according to the structures of diodes and the irradiation conditions

A Review on Microbial Mutagenesis through Gamma Irradiation for Agricultural Applications

International Nuclear Information System (INIS)

Hoe, P.C.K.; Khairuddin Abdul Rahim

2016-01-01

Gamma irradiation is widely used in sterilization and mutagenesis, especially for plant breeding and crop protection. Microbial mutagenesis through gamma irradiation is mainly applied in fermentation industry. In agriculture, gamma irradiation is mostly applied in crop improvement. Microbial mutagenesis is mainly applied against fungus and spore-forming bacteria, which are resistant to gamma irradiation. Response of microbes to gamma irradiation varies and depends on various factors. Review of previous works on gamma irradiation for microbial mutagenesis in agriculture may provide some information for the use of this method. The general view on gamma irradiation, its application, and mutagenesis are discussed in this paper. Further investigation on microbial mutagenesis should consider molecular changes, information on which is lacking in previous works. Moreover, studies on microbial mutagenesis are still lacking in Malaysia despite having several gamma irradiation facilities. Therefore, further studies on microbial mutagenesis should be conducted. (author)

Fatigue behavior of Type 316 stainless steel following neutron irradiation inducing helium

International Nuclear Information System (INIS)

Grossbeck, M.L.; Liu, K.C.

1980-01-01

Since a tokamak reactor operates in a cyclic mode, thermal stresses will result in fatigue in structural components, especially in the first wall and blanket. There has been limited work on fatigue in irradiated alloys but none on irradiated materials containing significant amounts of irradiation-induced helium. To provide scoping data and to study the effects of irradiation on fatigue behavior, 20%-cold-worked type 316 stainless steel from the MFE reference heat was studied

Stress state dependence of transient irradiation creep in 20% cold worked 316 stainless steel

International Nuclear Information System (INIS)

Foster, J.P.; Gilbert, E.R.

1998-01-01

Irradiation creep tests were performed in fast reactors using the stress states of uniaxial tension, biaxial tension, bending and torsion. In order to compare the saturated transient strain irradiation creep component, the test data were converted to equivalent strain and equivalent stress. The saturated transient irradiation creep component was observed to depend on the stress state. The highest value was exhibited by the uniaxial tension stress state, and the lowest by the torsion stress state. The biaxial tension and bending stress state transient component values were intermediate. This behavior appears to be related to the dislocation or microscopic substructure resulting from fabrication processing and the applied stress direction. (orig.)

Histochemical differentiation between unirradiated and gamma-irradiated tissue in commercial use of some irradiated vegetables

International Nuclear Information System (INIS)

Foa, E.

1978-01-01

The use of gamma irradiation as a commercial method for the preservation of fruits and vegetables calls for methods of differentiation between unirradiated and irradiated products. A new approach to studying the influence of gamma irradiation on vegetable tissue at the cellular level by histochemical techniques has been developed by the authors and already applied to a number of fruits and vegetables. The possibility of evidencing radiation effects in the polysaccharide components of the cell wall suggested that these detected differences could be applied to differentiate irradiated from unirradiated tomatoes and potatoes. Some work done to determine changes in the cell wall polysaccharides of gamma-irradiated potatoes and tomatoes and to relate these changes to some other factors, such as storage time and vegetable variety, is reported here. While significant differences have been found in the optical densities of the total polysaccharides of the cell wall as a function of irradiation and of the other variables mentioned, it is not yet possible to use these values as a means of reliable differentiation. (author)

Stress-stain relations of irradiated stainless steels below 673 K

International Nuclear Information System (INIS)

Jitsukawa, S.; Hishinuma, A.; Grossbeck, M.L.

1992-01-01

Most specimens, irrespective of thermo-mechnaical treatment, exhibited proof stress levels of above 800 MPa and uniform elongations below 1% after irradiation in the the High Flux Isotope Reactor (HFIR). Only the solution annealed specimens irradiated at a low temperature of 328 k showed uniform elongations larger than 5% and proof stresses smaller than 800 MPa. Irradiation in the High Flux Reactor (HFR) caused more hardening than did irradiation in the HFIR. Ductility loss and change in work hardening characteristics by HFR irradiation were evaluated from reduction of area values. Residual ductility was revealed to be larger than 0.5 in natural strain, and the irradiation was estimated to have a small effect on work hardening characteristics and on fracture stress. The ductility of the irradiated alloys was found to be about 58% of that for the unirradiated alloys, as has been previously reported for irradiation in the HFIR. It was also demonstrated that true stress-strain relations, except for the fracture conditions, could be represented by Swift's type constitutive equation. (orig.)

URAM-2 Cryogenic Irradiation Facility

CERN Document Server

Shabalin, E P; Kulikov, S A; Kulagin, E N; Melihov, V V; Belyakov, A A; Golovanov, L B; Borzunov, Yu T; Konstantinov, V I; Androsov, A V

2002-01-01

The URAM-2 irradiation facility has been built and mounted at the channel No. 3 of the IBR-2 reactor. It was constructed for study of radiolysis effects by fast neutron irradiation in some suitable for effective cold neutron production materials (namely: solid methane, methane hydrate, water ice, etc.). The facility cooling system is based on using liquid helium as a coolant material. The original charging block of the rig allows the samples to be loaded by condensing gas into irradiation cavity or by charging beads of ice prepared before. Preliminary tests for each facility block and assembling them at the working position were carried out. Use of the facility for study accumulation of chemical energy under irradiation at low temperature in materials mentioned above and its spontaneous release was started.

Dry storage of irradiated nuclear fuels and vitrified wastes

International Nuclear Information System (INIS)

Deacon, D.

1982-01-01

A review is given of the work of GEC Energy Systems Ltd. over the years in the dry storage of irradiated fuel. The dry-storage module (designated as Cell 4) for irradiated magnox fuel recently constructed at Wylfa nuclear power station is described. Development work on the long-term dry storage of irradiated oxide fuels is reported. Four different methods of storage are compared. These are the pond, vault, cask and caisson stores. It is concluded that there are important advantages with the passive air-cooled ESL dry stove. (U.K.)

Eatability of the irradiated food

International Nuclear Information System (INIS)

Luna C, P.C.

1992-05-01

A food is eatable and innocuous when it has an acceptable nutritional quality, it is toxicological and microbiologically safe for the human consumption. Not one preservation treatment allows to assure this in absolute form. As it happens with other conservation methods, the irradiation produce biological, chemical and physical changes in the treated food. For to check if such changes could cause damages to the health of the consumer, its have been carried out extensive studies to evaluate the inoculate of the irradiated foods. Analyzing diverse toxicity studies to prove the eatability of the irradiated foods, in this work those are presented but important in chronological order. In summary, until today it exists a great heap of tests that they demonstrate without place to doubts that the foods irradiated with a dose up to 10 KGy its are capable for the human consumption, for what can to be concluded that a safety margin exists to consume foods irradiated. (Author)

Radiation situation and irradiation level in forest workers in places of timber works in alienation zone of Chernobyl Atomic Power Plant

International Nuclear Information System (INIS)

Kalashnikova, Z.V.; Karachov, Yi.Yi.; Berezhna, T.Yi.; Kuchma, M.D.

1997-01-01

The radiation hygienic situation in the forest plots and dose load of the personnel at timber works in the alienation zone of the Chernobyl Atomic Power Plant was evaluated.It has been revealed that the density of contamination of the forest soil at the areas of timber works was 155.4-447.3 kBq centre dot m 2 . Maximum year equivalent dose on the lungs and total dose of external and internal irradiation in the forest workers in the zone of alienation during the work at the areas were about 40% of the values of the respective dose limits for the population of B category

Ecological applications of the irradiated adsorbents

International Nuclear Information System (INIS)

Tusseyev, T.

2004-01-01

Full text: In our previous works it was shown that after irradiation some adsorbents gain new interesting properties such as increasing (or decreasing) of their adsorption capacity, selectivity in relation to some gases, change of chemical bounds of gas molecules with adsorbent surface as well as other properties. We investigated a lot of adsorbents with semiconducting and dielectric properties. A high temperature superconductor was investigated also. Adsorbents were irradiated by ultraviolet (UV) and gamma - radiation, reactor (n.γ) - radiation, α-particles (E=40-50 MeV), protons ( E=30 MeV), and also He-3 ions (E-29-60 MeV). The following techniques were used: volumetric (manometrical), mass-spectrometer and IR spectroscopic methods, and also method of electronic - paramagnetic resonance (spin paramagnetic resonance) The obtained results allow to speak about creation of new adsorbents for gas purification (clearing) from harmful impurities, gas selection into components, an increasing of adsorbing surface. Thus one more advantage of the irradiated adsorbents is that they have 'memory effect', i.e. they can be used enough long time after irradiation. In laboratory conditions we built the small-sized adsorptive pump on the basis of the irradiated zeolites which are capable to work in autonomous conditions. It was found, that some of adsorbents after irradiation gain (or lose) selectivity in relation to definite gases. So, silica gel, which one in initial state does not adsorb hydrogen, after gamma irradiation it becomes active in relation to hydrogen. Some of rare earths oxides also show selectivity in relation to hydrogen and oxygen depending on a type of irradiation. Thus, it is possible to create different absorbents, depending on a solved problem, using a way or selection of adsorbents, either of radiation type and energy, as a result obtained adsorbents can be used for various ecological purposes

Neutron and X-ray diffraction analysis of the effect of irradiation dose and temperature on microstructure of irradiated HT-9 steel

International Nuclear Information System (INIS)

Mosbrucker, P.L.; Brown, D.W.; Anderoglu, O.; Balogh, L.; Maloy, S.A.; Sisneros, T.A.; Almer, J.; Tulk, E.F.; Morgenroth, W.; Dippel, A.C.

2013-01-01

Material harvested from several positions within a nuclear fuel duct (the ACO-3 duct) used in a 6-year irradiation of a fuel assembly in the Fast Flux Test Reactor Facility (FFTF) was examined using neutron and high-energy X-ray diffraction. Samples with a wide range of irradiation dose and irradiation temperature history, reaching doses of up to 147 dpa and temperatures of up to 777 K, were examined. The response of various microstructural characteristics such as the weight fraction of M 23 C 6 carbides, the dislocation density and character, and the crystallographic texture were determined using whole profile analysis of the diffraction data and related to the macroscopic mechanical behavior. For instance, the dislocation density was observed to be intimately linked with observed flow strength of the irradiated materials, following the Taylor law. In general, at the high doses studied in this work, the irradiation temperature is the predominant controlling factor of the dislocation density and, thus, the flow strength of the irradiated material. The results, representing some of the first diffraction work done on samples exposed to such a high received dose, demonstrate how non-destructive and stand-off diffraction techniques can be used to characterize irradiation induced microstructure and at least estimate mechanical properties in irradiated materials without exposing workers to radiation hazards

AGR-1 Post Irradiation Examination Final Report

Energy Technology Data Exchange (ETDEWEB)

Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-08-01

The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

Impact of socioeconomic characteristics on attitudes toward food irradiation

International Nuclear Information System (INIS)

Hinson, R.A.; Harrison, R.W.; Andrews, L.

1998-01-01

Irradiation of food products is one of several techniques that reduce the risk of food-borne illness. Despite its advantages, the technique has been used sparingly because consumers are wary about this technology. A logit model is used to evaluate the impacts of demographic factors on attitudes toward purchasing foods that have been irradiated and toward paying more for irradiated foods. An important finding of this study is that consumers who are familiar with irradiation are significantly more likely to buy and pay more for irradiated products than those who have never heard of irradiation. This implies that educational programs aimed at informing consumers about the benefits of irradiation can work

Early works on the nuclear microprobe for microelectronics irradiation tests at the CEICI (Sevilla, Spain)

International Nuclear Information System (INIS)

Palomo, F.R.; Morilla, Y.; Mogollon, J.M.; Garcia-Lopez, J.; Labrador, J.A.; Aguirre, M.A.

2011-01-01

Particle radiation effects are a fundamental problem in the use of numerous electronic devices for space applications, which is aggravated with the technology shrinking towards smaller and smaller scales. The suitability of low-energy accelerators for irradiation testing is being considered nowadays. Moreover, the possibility to use a nuclear microprobe, with a lateral resolution of a few microns, allows us to evaluate the behavior under ion irradiation of specific elements in an electronic device. The CEICI is the new CEnter for Integrated Circuits Irradiation tests, created into the facilities at the Centro Nacional de Aceleradores (CNA) in Sevilla-Spain. We have verified that our 3 MV Tandem accelerator, typically used for ion beam characterization of materials, is also a valuable tool to perform irradiation experiments in the low LET (Linear Energy Transfer) region.

Ions irradiation on bi-layer coatings

Science.gov (United States)

Tessarolo, Enrico; Corso, Alain Jody; Böttger, Roman; Martucci, Alessandro; Pelizzo, Maria G.

2017-09-01

Future space missions will operate in very harsh and extreme environments. Optical and electronics components need to be optimized and qualified in view of such operational challenges. This work focuses on the effect of low alpha particles irradiation on coatings. Low energy He+ (4 keV and 16 keV) ions have been considered in order to simulate in laboratory the irradiation of solar wind (slow and fast components) alpha particles. Mono- and proper bi-layers coatings have been investigated. The experimental tests have been carried out changing doses as well as fluxes during the irradiation sessions. Optical characterization in the UV-VIS spectral range and superficial morphological analysis have performed prior and after irradiation.

Steam-chemical reactivity for irradiated beryllium

Energy Technology Data Exchange (ETDEWEB)

Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

1998-01-01

This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

Estimation of shortwave direct aerosol radiative forcing at four locations on the Indo-Gangetic plains: Model results and ground measurement

Science.gov (United States)

Bibi, Humera; Alam, Khan; Bibi, Samina

2017-08-01

This study provides observational results of aerosol optical and radiative characteristics over four locations in IGP. Spectral variation of Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP) were analysed using AErosol RObotic NETwork (AERONET) data. The analysis revealed that coarse particles were dominant in summer and pre-monsoon, while fine particles were more pronounced in winter and post-monsoon. Furthermore, the spatio-temporal variations of Shortwave Direct Aerosol Radiative Forcing (SDARF) and Shortwave Direct Aerosol Radiative Forcing Efficiency (SDARFE) at the Top Of Atmosphere (TOA), SURface (SUR) and within ATMosphere (ATM) were calculated using SBDART model. The atmospheric Heating Rate (HR) associated with SDARFATM were also computed. It was observed that the monthly averaged SDARFTOA and SDARFSUR were found to be negative leading to positive SDARFATM during all the months over all sites. The increments in net atmospheric forcing lead to maximum HR in November-December and May. The seasonal analysis of SDARF revealed that SDARFTOA and SDARFSUR were negative during all seasons. The SW atmospheric absorption translates to highest atmospheric HR during summer over Karachi and during pre-monsoon over Lahore, Jaipur and Kanpur. Like SDARF, the monthly and seasonal variations of SDARFETOA and SDARFESUR were found to be negative, resulting in positive atmospheric forcing. Additionally, to compare the model estimated forcing against AERONET derived forcing, the regression analysis of AERONET-SBDART forcing were carried out. It was observed that SDARF at SUR and TOA showed relatively higher correlation over Lahore, moderate over Jaipur and Kanpur and lower over Karachi. Finally, the analysis of National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that air masses were arriving from multiple source locations.

Irradiation effects on organic insulators

International Nuclear Information System (INIS)

Kasen, M.B.

1986-01-01

The overall objective of this work is to contribute to development of organic insulators having the cryogenic neutron irradiation resistance required for MFE systems utilizing superconducting magnet confinement. The system for producing standard 3.2-mm (0.125-in) diameter rod specimens discussed in previous reports has been further refined to permit the fabrication of both fiber-reinforced and heat-resin specimens from hot-melt resin systems. The method has been successfully used to produce very high quality specimens duplicating the G-11CR system and specimens from a variant of that system eliminating a boron-containing additive. We have also produced specimens from an epoxy system suitable for impregnation or potting operations and from a bismaleimide polyimide system. These materials will be used in the first irradiation program in the National Low Temperature Neutron Irradiation Facility (NLTNIF) reactor at Oak Ridge. We have refined the 4-K torsional shear test method for evaluating radiation degradation of the fiber-matrix interface and have developed a method of quantitatively measuring changes in fracture energy as a function of radiation dose. Cooperative work with laboratories in Japan and England in this area is continuing and plans are being formulated for joint production, irradiation, and testing of specimens

Studies on the irradiated solids

International Nuclear Information System (INIS)

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

The proceedings of 1993-workshop on 'development and application of facilities for low temperature irradiation as well as controlled irradiation'

International Nuclear Information System (INIS)

Kuramoto, Eiichi; Okada, Moritami

1993-03-01

This is the proceedings of 1992-workshop of the working group on 'Development and Application of Facilities for Low Temperature Irradiation as well as Controlled Irradiation' held at the Research Reactor Institute of Kyoto University on February 23 and 24, 1993. In this workshop until now, studies on irradiation effects in many materials irradiated at lower and higher temperatures have been reported. It has been clearly defined that a careful choice of irradiation conditions is most important. At the present time, a setting plan of exactly controlled irradiation facility, which is able to irradiate with higher temperatures, is in progress. On the other hand, a plan of vertical low temperature irradiation facility has not yet been performed for lack of funds. In last year, a middle scale plan of low temperature irradiation facility, which is possible to irradiate a fast-neutron dose above 10 17 n/cm 2 at about 5K, was proposed in this workshop. In this proceedings, the advanced facility is required to construct to the KUR as soon as possible by many of the workshop members. (author)

Quantitative Comparison of the Variability in Observed and Simulated Shortwave Reflectance

Science.gov (United States)

Roberts, Yolanda, L.; Pilewskie, P.; Kindel, B. C.; Feldman, D. R.; Collins, W. D.

2013-01-01

The Climate Absolute Radiance and Refractivity Observatory (CLARREO) is a climate observation system that has been designed to monitor the Earth's climate with unprecedented absolute radiometric accuracy and SI traceability. Climate Observation System Simulation Experiments (OSSEs) have been generated to simulate CLARREO hyperspectral shortwave imager measurements to help define the measurement characteristics needed for CLARREO to achieve its objectives. To evaluate how well the OSSE-simulated reflectance spectra reproduce the Earth s climate variability at the beginning of the 21st century, we compared the variability of the OSSE reflectance spectra to that of the reflectance spectra measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY). Principal component analysis (PCA) is a multivariate decomposition technique used to represent and study the variability of hyperspectral radiation measurements. Using PCA, between 99.7%and 99.9%of the total variance the OSSE and SCIAMACHY data sets can be explained by subspaces defined by six principal components (PCs). To quantify how much information is shared between the simulated and observed data sets, we spectrally decomposed the intersection of the two data set subspaces. The results from four cases in 2004 showed that the two data sets share eight (January and October) and seven (April and July) dimensions, which correspond to about 99.9% of the total SCIAMACHY variance for each month. The spectral nature of these shared spaces, understood by examining the transformed eigenvectors calculated from the subspace intersections, exhibit similar physical characteristics to the original PCs calculated from each data set, such as water vapor absorption, vegetation reflectance, and cloud reflectance.

Irradiation service, a look at 2000

International Nuclear Information System (INIS)

Espinoza, Juan; Rubio, Tatiana

1999-01-01

Twenty years after the Multipurpose Irradiation Plant (PIM) operation was established, we think that it is about time to briefly review the experiences that have been carried out and to look at future challenges. Having defined the purpose of the PIM as the intermediate stage between laboratory studies and applications and their industrial development, the decision taken about one year ago to join the PIM's business with the irradiation sector is seen as a very positive strategy to strengthen the management capacity for both units and to provide a service with solid technical back-up and a renewed spirit. Over the last year we have been working at various levels simultaneously. Decisions have been made to integrate all the employees working in the PIM into a work team. A first diagnosis showed that if there were a group of employees with a good level of experience their activity should be consolidated into a team. An in-house training session was held for the irradiation section and the training Manual for irradiation plan operators, published by the International Food Irradiation Consultative Group (IFICG), is being studied and applied. With the support of the Information Unit a storage and operation control system is being developed using a bar code, which will improve the information about productive and administrative aspects as well as obtain better production statistics than what were previously available. A computer record of the Operation Logbook will automatically generate information about shifts, efficiency indicators for the plant and the operation, detention times, etc. The main quality control for the irradiation processes is the dosimetric control and the corresponding certification. The client base has expanded with validations of their product processes and the service provided is being certified, to become part of the food certification program. The advances made in the certification of our products has given our clients a better perception of our

Behaviour of irradiated uranium silicide fuel revisited

International Nuclear Information System (INIS)

Finlay, M. Ross; Hofman, Gerard L.; Rest, Jeffrey; Snelgrove, James L.

2002-01-01

Irradiated U 3 Si 2 dispersion fuels demonstrate very low levels of swelling, even at extremely high burn-up. This behaviour is attributed to the stability of fission gas bubbles that develop during irradiation. The bubbles remain uniformly distributed throughout the fuel and show no obvious signs of coalescence. Close examination of high burn-up samples during the U 3 Si 2 qualification program revealed a bimodal distribution of fission gas bubbles. Those observations suggested that an underlying microstructure was responsible for the behaviour. An irradiation induced recrystallisation model was developed that relied on the presence of sufficient grain boundary surface to trap and pin fission gas bubbles and prevent coalescence. However, more recent work has revealed that the U 3 Si 2 becomes amorphous almost instantaneously upon irradiation. Consequently, the recrystallisation model does not adequately explain the nucleation and growth of fission gas bubbles in U 3 Si 2 . Whilst it appears to work well within the range of measured data, it cannot be relied on to extrapolate beyond that range since it is not mechanistically valid. A review of the mini-plates irradiated in the Oak Ridge Research Reactor from the U 3 Si 2 qualification program has been performed. This has yielded a new understanding of U 3 Si 2 behaviour under irradiation. (author)

Electro-optical behaviour of silica optical fibers under transient ionizing irradiation

International Nuclear Information System (INIS)

Johan, A.; Charre, P.

1989-01-01

Centre d'Etudes de GRAMAT has perfected an experimental method on behaviour study for optical fiber under X-ray transient irradiation. This method allows recording of working light intensity in the fiber core or induced light (luminescence) during and after irradiation. The measured phenomena are the luminescence photon production and working light absorption. Monomode and multimode fiber behaviours have been studied and compared versus dose irradiation, light wavelength and injected optical power [fr

Piling up technology of goods irradiated by single plate source

International Nuclear Information System (INIS)

Xia Hezhou; Chen Yuxia; Cao Hongyun; Lin Yong; Zhou guoquan

1999-01-01

In the irradiation process of piling up goods in static state, four irradiation working sites and single plate source was adopted. The results showed that piling up in this way remarkably raised the irradiation quality of goods. The utilization rate of radioactive ray reached 22.27%

Microstructure of irradiated materials

International Nuclear Information System (INIS)

Robertson, I.M.

1995-01-01

The focus of the symposium was on the changes produced in the microstructure of metals, ceramics, and semiconductors by irradiation with energetic particles. the symposium brought together those working in the different material systems, which revealed that there are a remarkable number of similarities in the irradiation-produced microstructures in the different classes of materials. Experimental, computational and theoretical contributions were intermixed in all of the sessions. This provided an opportunity for these groups, which should interact, to do so. Separate abstracts were prepared for 58 papers in this book

Review of intense irradiation data and discussion on structural integrity

Energy Technology Data Exchange (ETDEWEB)

Suzuki, K.; Jitsukawa, S.; Okubo, N. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan)

2007-07-01

Full text of publication follows: Mechanical property data on austenitic stainless steels and F82H have been reviewed to discuss for developing structural integrity methodologies of intensely irradiated components such as first walls. The following have been already clarified: (1) Fracture ductility is still high even though tensile rupture elongation is reduced remarkably. (2) Strain-hardening occurs in true stress-logarithmic strain (true strain) relationship. Work-softening behavior observed in nominal stress-nominal strain curves is simply resulted from a reduction of work hardening rate accompanied by the increase of flow stress level by irradiation. The review lead to an innovative design concept for application to intensely irradiated components. A special consideration is given to unique feature of bending moment in developing design methodology for preventing ductile fracture of intensely irradiated materials. Another discussion is also made on how to simulate mechanical behavior of intensely irradiated components, because mechanical testing of component-wise specimens after intense irradiation is inevitable for the development of design concepts, although irradiation on such a large scale specimen seems to be almost impossible with current irradiation facilities. (authors)

Response of neutron-irradiated RPV steels to thermal annealing

International Nuclear Information System (INIS)

Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

1997-01-01

One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels

The Influence of a Sandy Substrate, Seagrass, or Highly Turbid Water on Albedo and Surface Heat Flux

Science.gov (United States)

Fogarty, M. C.; Fewings, M. R.; Paget, A. C.; Dierssen, H. M.

2018-01-01

Sea-surface albedo is a combination of surface-reflected and water-leaving irradiance, but water-leaving irradiance typically contributes less than 15% of the total albedo in open-ocean conditions. In coastal systems, however, the bottom substrate or suspended particulate matter can increase the amount of backscattered light, thereby increasing albedo and decreasing net shortwave surface heat flux. Here a sensitivity analysis using observations and models predicts the effect of light scattering on albedo and the net shortwave heat flux for three test cases: a bright sand bottom, a seagrass canopy, and turbid water. After scaling to the full solar shortwave spectrum, daytime average albedo for the test cases is up to 0.20 and exceeds the value of 0.05 predicted using a commonly applied parameterization. Daytime net shortwave heat flux into the water is significantly reduced, particularly for waters with bright sediments, dense horizontal seagrass canopies waters with suspended particulate matter concentration ≥ 50 g m-3. Observations of a more vertical seagrass canopy within 0.2 and 1 m of the surface indicate the increase in albedo compared to the common parameterization is negligible. Therefore, we suggest that the commonly applied albedo lookup table can be used in coastal heat flux estimates in water as shallow as 1 m unless the bottom substrate is highly reflective or the water is highly turbid. Our model results provide guidance to researchers who need to determine albedo in highly reflective or highly turbid conditions but have no direct observations.

Materials of 15. autumn school on irradiated food

International Nuclear Information System (INIS)

1994-01-01

The ionizing radiation use for food preservation has been shown on the background of other methods. Several aspects connected with food irradiation have been discussed. Among them the legal aspects and recommendations have been performed. The healthy aspects from the view point of the radiolysis of main components of irradiated food have been presented. The broad review of physical, chemical and biological methods for identification of irradiated food products has been done. The accelerator pilot plant for food irradiation working at the Institute of Nuclear Chemistry and Technology, Warsaw, has been presented as well

Irradiation-induced permeability in pyrocarbon coatings. Final report of work conducted under PWS FD-12

International Nuclear Information System (INIS)

Kania, M.J.; Thiele, B.A.; Homan, F.J.

1982-10-01

Two US irradiation experiments were planned to provide information to supplement data from the German program on irradiation-induced permeability in pyrocarbon coatings. Hopefully, the data from both programs could be combined to define the onset of neutron-induced permeability in a variety of Biso coatings produced with different process variables (coating temperature, coating gases, and coating rates). The effort was not successful. None of the preirradiation characterization procedures were able to adequately predict irradiation performance. A large amount of within-batch scatter was observed in the fission gas and cesium release data along with significant within-batch variation in coating properties. Additional preirradiation characterization might result in a procedure that could successfully predict irradiation performance, but little can be done about the within-batch variation in coating properties. This variation is probably the result of random movement of particles within the coating furnace during pyrocarbon deposition. 19 figures, 4 tables

Effect of helium irradiation on fracture modes

International Nuclear Information System (INIS)

Hanamura, T.; Jesser, W.A.

1982-01-01

The objective of this work is to determine the crack opening mode during in-situ HVEM tensile testing and how it is influenced by test temperature and helium irradiation. Most cracks were mixed mode I and II. However, between 250 0 C and room temperature the effect of helium irradiation is to increase the amount of mode I crack propagation. Mode II crack opening was observed as grain boundary sliding initiated by a predominantly mode I crack steeply intersecting the grain boundary. Mode II crack opening was absent in irradiated specimens tested between 250 0 C and room temperature, but could be restored by a post irradiation anneal

Food Irradiation Newsletter. V. 12, no. 2

International Nuclear Information System (INIS)

1988-07-01

This Newsletter reports activities of two ICGFI training workshops convened in Santiago, Chile, and Rehovot, Israel, in the past six months. The summary report of the FAO/IAEA Seminar on Food Irradiation for Developing Countries in Africa is also included. A follow-up to this Seminar is the ''Co-ordinated Research Programme on Food Irradiation for African Countries'' which will be implemented as soon as funds become available. Further, this issue contains a report of the Working Group on Food Irradiation of the European Society for Nuclear Agriculture convened in Stara Zagora, Bulgaria in 1987 and status reports of practical applications of food irradiation in different countries. 2 tabs

Effects of prior stress history on the irradiation creep of 20% cold-worked AISI 316 stainless steel

International Nuclear Information System (INIS)

Chin, B.A.; Straalsund, J.L.; Wire, G.L.

1979-01-01

The following conclusions resulted from this study: An in-reactor transient component of creep is found to occur whenever the stress level is increased. The transient is principally a thermal process, short in duration, and only weakly dependent on flux. The observed irradiation component of in-reactor creep is independent of prior stress history. Microstructural development during irradiation is influenced predominantly by the irradiation flux and temperature variables, and only to a minor extent by the irradiation stress history. (Auth.)

Awareness on food irradiation among students

International Nuclear Information System (INIS)

Seri Chempaka Mohd Yusof; Foziah Ali; Salahbiah Abdul Majid; Ros Anita Ahmad Ramli; Zainab Harun

2009-01-01

This survey was conducted to determine the level of understanding on radiation and irradiated food products amongst students during an exhibition in conjunction with Nuclear Malaysia Innovation Day 2008, on 16-18 July 2008 at Dewan Tun Dr. Ismail, Malaysian Nuclear Agency. Data were collected from 180 respondents comprising students from various schools visiting the exhibition. The results revealed that 55.56 % of the respondents knew of radiation and 81.11 % agreed that food could be irradiated. However, 53.33 % respondents misunderstood that there was presence of radioactivity in the food after irradiation. The results also showed that respondents knew that various foods can be irradiated and the type of radiation used in irradiation of food products. This survey indicates more aggressive work must be done to educate and introduce the public the application of nuclear technology in modern life, including in food preservation. (Author)

Mechanical properties of low temperature proton irradiated single crystal copper

International Nuclear Information System (INIS)

Schildcrout, M.

1975-01-01

Single crystal copper samples, of varying degrees of cold work, were irradiated near either liquid helium or liquid nitrogen temperature by 10.1-MeV protons. The internal friction and dynamic Young's modulus were observed as a function of either temperature or integrated proton flux. The primary effect of irradiation was to produce dislocation pinning. The initial pinning rate was found to be very sensitive to cold work. During irradiation it was found that heavily cold worked samples (25 percent compression) exhibited, almost exclusively, exponential pinning given by Y = e/sup --lambda phi/. This is attributed to the immobilization, rather than shortening, of loop lengths and is characterized by the pinning constant lambda. Exponential pinning was also found, to a smaller degree, in less heavily cold worked samples. Cold work appears to reduce the ''effective volume'' within which the defect clusters produced by irradiation, can immobilize dislocation segments. The bulk effect was observed after dislocation pinning was completed. Expressed in terms of the fractional change in Young's modulus per unit concentration of irradiation induced defects, it was measured at liquid helium temperature to be --18.5 +- 3. An anelastic process occurring near 10 0 K for low kHz frequencies and due to stress-induced ordering of point defects produced by irradiation has also been studied. The peak height per unit fluence was found to decrease with increasing cold work. The peak was not observed in samples compressed 25 percent. For the most carefully handled sample the activation energy was (1.28 +- 0.05) x 10 -2 eV, the attempt frequency was 10/sup 11.6 +- .8/ s -1 , the shape factor was 0.20, and the half width of the peak was 11 percent larger than the theoretical value calculated from the Debye equation for a single relaxation process

Food irradiation development: Malaysian perspective

International Nuclear Information System (INIS)

Zainon Othman

1997-01-01

Malaysia recognised the potential of food irradiation as a technology that can contribute to solving some preservation problems associated with local agricultural produce. Research studies in this technology were initiated in late 1970s and since 1985, all activities pertaining to R and D applications, adoption and technology transfer of food irradiation were coordinated by The National Working Committee on Food Irradiation which comprises of members from research institutes, universities, regulatory agencies and consumer association. To date, technical feasibility studies conducted on 7 food items / agricultural commodities of economic importance demonstrated the efficacy of irradiation in extending shelf-life, improving hygienic quality and overcoming quarantine barriers in trade. Presently, 1 multipurpose Co-60 irradiator (I MCi), 2 gammacells and an electron beam machine (3 MeV) are available at MINT for research and commercial runs. The Malaysian Standards on Guidelines for Irradiation of Food was formulated in 1992 to facilitate application by local food industries. However, Malaysia has not yet commercially adopt the technology. Among many factors contributing to the situation is the apparent lack of interest by food industries and consumers. Consumer attitude study indicated majority of consumers are still unaware of the benefits of the technology and expressed concern for the safety of process and irradiated products due to limited knowledge and adverse publicity by established consumer groups. Although the food processors indicate positive attitude towards food irradiation, there remain many factors delaying its commercial application such as limited knowledge, cost-benefit, logistics and consumer acceptance. On the regulatory aspect, approval is required from the Director-General of Ministry of Health prior to application of irradiation on food and sale of irradiated food but efforts are being geared towards approving irradiation of certain food

Swelling and irradiation creep of neutron irradiated 316Ti and 15-15Ti steels

International Nuclear Information System (INIS)

Maillard, A.; Touron, H.; Seran, J.L.; Chalony, A.

1992-01-01

The global behavior, the swelling and irradiation creep resistances of cold worked 316Ti and 15-15Ti, two variants of austenitic steels in use as core component materials of the French fast reactors, are compared. The 15-15Ti leads to a significant improvement due to an increase in the incubation dose swelling. The same phenomena observed on 316Ti are found on 15-15Ti. All species without fuel like samples, wrappers or empty clad swell and creep less than fuel pin cladding irradiated in the same conditions. To explain the swelling difference, as for 316Ti, thermal gradient is also invoked but the irradiation creep difference is not yet clearly understood. To predict the behavior of clads it is indispensable to study the species themselves and to use specific rules. All results confirm the good behavior of 15-15Ti, the best behavior being obtained with the 1% Si doped version irradiated up to 115 dpa

Food irradiation

International Nuclear Information System (INIS)

Roberts, P.B.

1997-01-01

Food can be provided with extra beneficial properties by physical processing. These benefits include a reduced possibility of food poisoning, or an increased life of the food. We are familiar with pasteurisation of milk, drying of vegetables, and canning of fruit. These physical processes work because the food absorbs energy during treatment which brings about the changes needed. The energy absorbed in these examples is heat energy. Food irradiation is a less familiar process. It produces similar benefits to other processes and it can sometimes be applied with additional advantages over conventional processing. For example, because irradiation causes little heating, foods may look and taste more natural. Also, treatment can take place with the food in its final plastic wrappers, reducing the risk of re-contamination. (author). 1 ref., 4 figs., 1 tab

Profitability of irradiation plants

International Nuclear Information System (INIS)

Bustos R, M.E.; Gonzalez F, C.; Liceaga C, G.; Ortiz A, G.

1997-01-01

In any industrial process it is seek an attractive profit from the contractor and the social points of view. The use of the irradiation technology in foods allows keep their hygienically, which aid to food supply without risks for health, an increment of new markets and a losses reduction. In other products -cosmetics or disposable for medical use- which are sterilized by irradiation, this process allows their secure use by the consumers. The investment cost of an irradiation plant depends mainly of the plant size and the radioactive material reload that principally is Cobalt 60, these two parameters are in function of the type of products for irradiation and the selected doses. In this work it is presented the economic calculus and the financial costs for different products and capacities of plants. In general terms is determined an adequate utility that indicates that this process is profitable. According to the economic and commercial conditions in the country were considered two types of credits for the financing of this projects. One utilizing International credit resources and other with national sources. (Author)

The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds

Energy Technology Data Exchange (ETDEWEB)

Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre

1996-12-31

Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.

Shortwave and longwave radiative contributions to global warming under increasing CO2

Science.gov (United States)

Donohoe, Aaron; Armour, Kyle C.; Pendergrass, Angeline G.; Battisti, David S.

2014-01-01

In response to increasing concentrations of atmospheric CO2, high-end general circulation models (GCMs) simulate an accumulation of energy at the top of the atmosphere not through a reduction in outgoing longwave radiation (OLR)—as one might expect from greenhouse gas forcing—but through an enhancement of net absorbed solar radiation (ASR). A simple linear radiative feedback framework is used to explain this counterintuitive behavior. It is found that the timescale over which OLR returns to its initial value after a CO2 perturbation depends sensitively on the magnitude of shortwave (SW) feedbacks. If SW feedbacks are sufficiently positive, OLR recovers within merely several decades, and any subsequent global energy accumulation is because of enhanced ASR only. In the GCM mean, this OLR recovery timescale is only 20 y because of robust SW water vapor and surface albedo feedbacks. However, a large spread in the net SW feedback across models (because of clouds) produces a range of OLR responses; in those few models with a weak SW feedback, OLR takes centuries to recover, and energy accumulation is dominated by reduced OLR. Observational constraints of radiative feedbacks—from satellite radiation and surface temperature data—suggest an OLR recovery timescale of decades or less, consistent with the majority of GCMs. Altogether, these results suggest that, although greenhouse gas forcing predominantly acts to reduce OLR, the resulting global warming is likely caused by enhanced ASR. PMID:25385628

Shortwave and longwave radiative contributions to global warming under increasing CO2.

Science.gov (United States)

Donohoe, Aaron; Armour, Kyle C; Pendergrass, Angeline G; Battisti, David S

2014-11-25

In response to increasing concentrations of atmospheric CO2, high-end general circulation models (GCMs) simulate an accumulation of energy at the top of the atmosphere not through a reduction in outgoing longwave radiation (OLR)—as one might expect from greenhouse gas forcing—but through an enhancement of net absorbed solar radiation (ASR). A simple linear radiative feedback framework is used to explain this counterintuitive behavior. It is found that the timescale over which OLR returns to its initial value after a CO2 perturbation depends sensitively on the magnitude of shortwave (SW) feedbacks. If SW feedbacks are sufficiently positive, OLR recovers within merely several decades, and any subsequent global energy accumulation is because of enhanced ASR only. In the GCM mean, this OLR recovery timescale is only 20 y because of robust SW water vapor and surface albedo feedbacks. However, a large spread in the net SW feedback across models (because of clouds) produces a range of OLR responses; in those few models with a weak SW feedback, OLR takes centuries to recover, and energy accumulation is dominated by reduced OLR. Observational constraints of radiative feedbacks—from satellite radiation and surface temperature data—suggest an OLR recovery timescale of decades or less, consistent with the majority of GCMs. Altogether, these results suggest that, although greenhouse gas forcing predominantly acts to reduce OLR, the resulting global warming is likely caused by enhanced ASR.

Tensile behavior of irradiated manganese-stabilized stainless steel

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L. [Oak Ridge National Lab., TN (United States)

1996-10-01

Tensile tests were conducted on seven experimental, high-manganese austenitic stainless steels after irradiation up to 44 dpa in the FFTF. An Fe-20Mn-12Cr-0.25C base composition was used, to which various combinations of Ti, W, V, B, and P were added to improve strength. Nominal amounts added were 0.1% Ti, 1% W, 0.1% V, 0.005% B, and 0.03% P. Irradiation was carried out at 420, 520, and 600{degrees}C on the steels in the solution-annealed and 20% cold-worked conditions. Tensile tests were conducted at the irradiation temperature. Results were compared with type 316 SS. Neutron irradiation hardened all of the solution-annealed steels at 420, 520, and 600{degrees}C, as measured by the increase in yield stress and ultimate tensile strength. The steel to which all five elements were added to the base composition showed the least amount of hardening. It also showed a smaller loss of ductility (uniform and total elongation) than the other steels. The total and uniform elongations of this steel after irradiation at 420{degrees}C was over four times that of the other manganese-stabilized steels and 316 SS. There was much less difference in strength and ductility at the two higher irradiation temperatures, where there was considerably less hardening, and thus, less loss of ductility. In the cold-worked condition, hardening occured only after irradiation at 420{degrees}C, and there was much less difference in the properties of the steels after irradiation. At the 420{degrees}C irradiation temperature, most of the manganese-stabilized steels maintained more ductility than the 316 SS. After irradiation at 420{degrees}C, the temperature of maximum hardening, the steel to which all five of the elements were added had the best uniform elongation.

The early effects in the brain after irradiation with carbon ions using mice

International Nuclear Information System (INIS)

Takai, Nobuhiko; Nakamura, Saori; Ohba, Yoshihito; Uzawa, Akiko; Furusawa, Yoshiya; Koike, Sachiko; Matsumoto, Yoshitaka; Hirayama, Ryoichi

2011-01-01

This study investigated both early and late effects in the brain after irradiation with carbon ions using mice. The irradiation dose was set at level known to produce vascular change followed by necrosis, which appeared the late period after irradiation with 30 Gy. The whole of brain was irradiated, excluding eyes and brain stem. The mice irradiated with single dose of 30 Gy showed deficit in short-term working memory assessed at 36 hr after irradiation, whereas mice receiving carbon irradiation showed no deficit in long-term reference memory. At 16 weeks after irradiation, the irradiated mice showed marked learning impairment compared with age-matched controls and the irradiated mice showed substantial impairment of working memory. Histopathological observation revealed no abnormal finding in the irradiated brain at 36 hr after irradiation, although irradiated mice showed marked neuronal degeneration at the hippocampus within CA1 to CA3 layers at 16 weeks after irradiation. In the irradiated group, neuronal cells in the hippocampal CA1-3 areas were reduced by 30-49%. These results suggest that although irradiation-induced hippocampal degeneration is associated with learning disability, cognitive deficits may also be detected on the early stage, not associated with hippocampal degeneration. (author)

Estimating net surface shortwave radiation from Chinese geostationary meteorological satellite FengYun-2D (FY-2D) data under clear sky.

Science.gov (United States)

Zhang, Xiaoyu; Li, Lingling

2016-03-21

Net surface shortwave radiation (NSSR) significantly affects regional and global climate change, and is an important aspect of research on surface radiation budget balance. Many previous studies have proposed methods for estimating NSSR. This study proposes a method to calculate NSSR using FY-2D short-wave channel data. Firstly, a linear regression model is established between the top-of-atmosphere (TOA) broadband albedo (r) and the narrowband reflectivity (ρ1), based on data simulated with MODTRAN 4.2. Secondly, the relationship between surface absorption coefficient (as) and broadband albedo (r) is determined by dividing the surface type into land, sea, or snow&ice, and NSSR can then be calculated. Thirdly, sensitivity analysis is performed for errors associated with sensor noise, vertically integrated atmospheric water content, view zenith angle and solar zenith angle. Finally, validation using ground measurements is performed. Results show that the root mean square error (RMSE) between the estimated and actual r is less than 0.011 for all conditions, and the RMSEs between estimated and real NSSR are 26.60 W/m2, 9.99 W/m2, and 23.40 W/m2, using simulated data for land, sea, and snow&ice surfaces, respectively. This indicates that the proposed method can be used to adequately estimate NSSR. Additionally, we compare field measurements from TaiYuan and ChangWu ecological stations with estimates using corresponding FY-2D data acquired from January to April 2012, on cloud-free days. Results show that the RMSE between the estimated and actual NSSR is 48.56W/m2, with a mean error of -2.23W/m2. Causes of errors also include measurement accuracy and estimations of atmospheric water vertical contents. This method is only suitable for cloudless conditions.

Detection of irradiated food by differential scanning calorimetry

International Nuclear Information System (INIS)

Nesvadba, P.; Kent, M.

1991-01-01

It has been showed that the freezing point of chicken is depressed on irradiation and that this can serve as a possible method of detection of irradiated chicken. The purposed of the present work was to see whether other foods (cod, mushroom) show the freezing point depression

Food irradiation developments in the Federal Republic of Germany

International Nuclear Information System (INIS)

Diehl, J.F.

1985-01-01

Professor Diehl from Karlsruhe describes work in the Federal Republic of Germany, based on 30 years of research work at the Centre for Nutrition at Karlsruhe. The replacement of toxic chemical preservatives by irradiation is an attractive possibility and permission for commercial spice irradiation is expected later this year. Promising results had been demonstrated for onions, tropical fruits, fish, shrimps, certain meats and enzymes. Prolonged wholesomeness studies has failed to reveal detrimental health effects up to 50 kGy. In spite of certain adverse political and emotional pressures the author is convinced that food irradiation will be permitted in all E.E.C. countries in the not too distant future

"Radiative Closure Studies for Clear Skies During the ARM 2003 Aerosol Intensive Observation Period"

Energy Technology Data Exchange (ETDEWEB)

J. J. Michalsky, G. P. Anderson, J. Barnard, J. Delamere, C. Gueymard, S. Kato, P. Kiedron, A. McComiskey, and P. Ricchiazzi

2006-04-01

The Department of Energy's Atmospheric Radiation Measurement (ARM) program sponsored a large intensive observation period (IOP) to study aerosol during the month of May 2003 around the Southern Great Plains (SGP) Climate Research Facility (CRF) in north central Oklahoma. Redundant measurements of aerosol optical properties were made using different techniques at the surface as well as in vertical profile with sensors aboard two aircraft. One of the principal motivations for this experiment was to resolve the disagreement between models and measurements of diffuse horizontal broadband shortwave irradiance at the surface, especially for modest aerosol loading. This paper focuses on using the redundant aerosol and radiation measurements during this IOP to compare direct beam and diffuse horizontal broadband shortwave irradiance measurements and models at the surface for a wide range of aerosol cases that occurred during 30 clear-sky periods on 13 days of May 2003. Models and measurements are compared over a large range of solar-zenith angles. Six different models are used to assess the relative agreement among them and the measurements. Better agreement than previously achieved appears to be the result of better specification of input parameters and better measurements of irradiances than in prior studies. Biases between modeled and measured direct irradiances are less than 1%, and biases between modeled and measured diffuse irradiances are less than 2%.

Gamma-irradiation of wet corn. Microbiological aspects

International Nuclear Information System (INIS)

Poisson, Jeanne; Cahagnier, B.

1973-01-01

In the course of a survey of several years work on microbiological decontamination and control of wet corn by gamma-irradiation the following factors are studied: inhibiting and selective effect of gamma-irradiation (100 to 500krads) on the microflora of grains; evolution of residual microflora of irradiated wet grains (moisture content about 35%), during storage experiments under ventilated or airtight conditions. Two important points emerge from those studies. The microflora which develops on irradiated sample is much less varied than that of the control sample. The microbial population of an irradiated sample rises up in a few days on a level with the initial one of the control, then goes on increasing while remaining, as a rule, slightly inferior to that of the control placed under the same conditions. This greatly lowers the practical interest of irradiation, which can only be used together with another treatment able to inhibit the quick growth of the residual microflora [fr

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

International Nuclear Information System (INIS)

Santos, Paulo S.; Vasquez, Pablo A.S.

2015-01-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

Energy Technology Data Exchange (ETDEWEB)

Santos, Paulo S.; Vasquez, Pablo A.S., E-mail: psantos@ipen.br, E-mail: pavsalva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Food Preservation by Irradiation. Vol. II. Proceedings of an International Symposium on Food Preservation by Irradiation

International Nuclear Information System (INIS)

1978-01-01

In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method of food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction of food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution of which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion of information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness studies

Food Preservation by Irradiation. Vol. I. Proceedings of an International Symposium on Food Preservation by Irradiation

International Nuclear Information System (INIS)

1978-01-01

In the task of alleviating the distress caused by the world-wide food shortage it is essential to preserve what has been grown and harvested in the fields. Clearly all suitable methods for preserving agricultural produce and food should be made use of. In this context treatment with ionizing radiation has proved its value as an environmentally clean, physical method o f food preservation which is low in its energy requirement, but the volume of food being processed in this way is still low. The introduction o f food irradiation on a global basis poses certain economic, legal, regulatory and health-related questions, the solution o f which requires close international collaboration. Such collaboration between many international, intergovernmental and national organizations began over a decade ago. The need for dissemination and discussion o f information gained through research and development work on this subject became apparent, and a number of inter-regional meetings were held. The last international symposium on the topic was held jointly by FAO and the IAEA in 1972 in Bombay. To review progress made since then, FAO and the IAEA, together with WHO, convened the present Symposium on 21-25 November 1977. It appeared timely to hold this Symposium for the following reasons: (1) Apart from significant scientific work reported in the literature, progress in other directions between 1972 and 1977 had also been made. For example, the number of food items authorized by governments, with or without restriction, had grown from 19 to 26, and the number of countries accepting one or more irradiated foods for human consumption had increased from 11 to 19. (2) Largely on the basis of the work of the International Project in the Field of Food Irradiation (Karlsruhe), already described at the Bombay Symposium, an international expert committee, jointly convened by FAO, the IAEA and WHO in August-September 1976, had made important statements on the philosophy of wholesomeness

Field measurement of clear-sky solar irradiance in Badain Jaran Desert of Northwestern China

International Nuclear Information System (INIS)

Bi, Jianrong; Huang, Jianping; Fu, Qiang; Ge, Jinming; Shi, Jinsen; Zhou, Tian; Zhang, Wu

2013-01-01

The Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) sponsored and conducted an intensive field campaign on dust aerosols in Badain Jaran Desert of Northwestern China from April 20 to June 20, 2010. A set of state-of-the-art broadband radiometers and sun/sky photometers were deployed along with launched radiosonde. In this paper, we compared the simulated solar irradiances by using the SBDART radiative transfer model with those from the ground-based measurements for 69 selected cases of 7 days. It was shown that the averaged aerosol optical depth at 500 nm (AOD 500 ) is 0.18±0.09 with AOD 500 less than 0.5 for all cases. The single-scattering albedo and asymmetry factor at 675 nm are 0.928±0.035, 0.712±0.023, respectively. The AODs retrieved from the CIMEL sun photometer at various wavelengths agree well with those from the PREDE sky radiometer, and the columnar water vapor contents from CIMEL also agree well with radiosonde observations. In the radiative closure experiment, we used a collocated thermopile pyrgeometer with a shadow and ventilator to correct the thermal dome offset of diffuse irradiance measurement. The mean differences between model and measurements are −9.1 Wm −2 (−2.6%) for the direct irradiance, +3.1 Wm −2 (+2.8%) for diffuse irradiance, and −6.0 Wm −2 (−1.3%) for global irradiance, which indicates an excellent radiative closure. Aerosol shortwave direct radiative forcing (ARF) and radiative heating rate are also investigated. The daily mean ARF ranges from −4.8 to +0.4 Wm −2 at the top of the atmosphere, −5.2 to −15.6 Wm −2 at the surface, and 5.2 to 10.8 Wm −2 in the atmosphere. The corresponding radiative heating rates for the whole atmosphere due to dust aerosols are 0.07, 0.11, 0.14, 0.11, 0.10, 0.08, and 0.07 K/day for the 7 selected cloudless days. These solar radiative forcing can be considered as the representative impact of background dust aerosol in Northwestern China

Thrombogenicity tests on ar-irradiated polycarbonate foils

Energy Technology Data Exchange (ETDEWEB)

Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H., E-mail: g.ferraz@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica; Delgado, Adriana O. [Universidade Federal de Sao Carlos (UFSCAR), Sorocaba, SP (Brazil); Cunha, Tatiana F. [Biosintesis P and D do Brasil, Sao Paulo, SP (Brazil); Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

2013-07-01

Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

Thrombogenicity tests on ar-irradiated polycarbonate foils

International Nuclear Information System (INIS)

Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H.; Cunha, Tatiana F.; Higa, Olga Z.

2013-01-01

Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

Impact of shortwave ultraviolet (UV-C) radiation on the antioxidant activity of thyme (Thymus vulgaris L.).

Science.gov (United States)

Dogu-Baykut, Esra; Gunes, Gurbuz; Decker, Eric Andrew

2014-08-15

Thyme is a good source of antioxidant compounds but it can be contaminated by microorganisms. An experimental fluid bed ultraviolet (UV) reactor was designed for microbial decontamination of thyme samples and the effect of shortwave ultraviolet light (UV-C) radiation on antioxidant properties of thyme was studied. Samples were exposed to UV-C radiation for 16 or 64 min. UV-C treatment led to 1.04 and 1.38 log CFU/g reduction of total aerobic mesophilic bacteria (TAMB) counts. Hunter a(∗) value was the most sensitive colour parameter during UV-C treatment. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of extracts was not significantly affected by UV-C. Addition of thyme extracts at 0.15 and 0.3 μmol GAE/ml emulsion delayed the formation of lipid hydroperoxides and headspace hexanal in the 5.0%(wt) corn oil-in-water emulsion from 4 to 9 and 14 days, respectively. No significant changes in oxidation rates were observed between UV-C treated and untreated samples at same concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Technology of irradiation of liquids by electron beams

International Nuclear Information System (INIS)

Tofaute, K.

1979-01-01

The methods of pretreatment, the technical details of the irradiating equipment, the applied radiation doses and the general requirements of the effectively working system are described. The extent of reinfection is compared in cases of heat-treated and electron-irradiated mud. The latter method gave significantly better results. (L.E.)

Hydrogen release from irradiated vanadium alloy V-4Cr-4Ti

Energy Technology Data Exchange (ETDEWEB)

Klepikov, A.Kh. E-mail: klepikov@ietp.alma-ata.su; Romanenko, O.G.; Chikhray, Y.V.; Tazhibaeva, I.L.; Shestakov, V.P.; Longhurst, G.R. E-mail: gxl@inel.gov

2000-11-01

The present work is an attempt to obtain data concerning the influence of neutron and {gamma} irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 10{sup 14} n/cm{sup 2} s, hydrogen pressure of 80 Pa, and temperatures of 563, 613 and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples.

Hydrogen release from irradiated vanadium alloy V-4Cr-4Ti

International Nuclear Information System (INIS)

Klepikov, A.Kh.; Romanenko, O.G.; Chikhray, Y.V.; Tazhibaeva, I.L.; Shestakov, V.P.; Longhurst, G.R.

2000-01-01

The present work is an attempt to obtain data concerning the influence of neutron and γ irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 10 14 n/cm 2 s, hydrogen pressure of 80 Pa, and temperatures of 563, 613 and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples

A simple and efficient gamma irradiator for RVNRL

Energy Technology Data Exchange (ETDEWEB)

Smolko, E; Ferenaz, G; Docters, E [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-12-31

This work describes a new design of a gamma irradiator for RVNRL which obeys a reliable operation and an efficient economical equation. Our irradiator is of a nobel design according to present requirements of latex industries and to the state of the art of radiation technology. The irradiator is of a wet storage type, where the radioactive sources are fixed in the reactor vessel, permanently submerged in deionized water. Preformulated latex is pumped from a deposited vessel into the reactor vessel and it is recirculated during the irradiation cycle avoiding turbulences and dose inhomogeneities. The irradiation time per one ton batch with a Co-60 charge of 3.5E15 Bq (100 kCi) is of approximately 4 hours

A simple and efficient gamma irradiator for RVNRL

International Nuclear Information System (INIS)

Smolko, E.; Ferenaz, G.; Docters, E.; Keizo Makuuchi

1996-01-01

This work describes a new design of a gamma irradiator for RVNRL which obeys a reliable operation and an efficient economical equation. Our irradiator is of a nobel design according to present requirements of latex industries and to the state of the art of radiation technology. The irradiator is of a wet storage type, where the radioactive sources are fixed in the reactor vessel, permanently submerged in deionized water. Preformulated latex is pumped from a deposited vessel into the reactor vessel and it is recirculated during the irradiation cycle avoiding turbulences and dose inhomogeneities. The irradiation time per one ton batch with a Co-60 charge of 3.5E15 Bq (100 kCi) is of approximately 4 hours

Creation of a plant for gamma-sterilization of the medical equipment and irradiation of industrial materials

International Nuclear Information System (INIS)

Maltceva, F.; Petukhov, V.; Chekushin, A.

1996-01-01

The purpose of the project. To create a powerful irradiation devices allowing to fulfill the irradiation of large-sized objects with dozes up to 4 Rad, and caring out the irradiation technologies by using of it. The basic tasks of the project and sequence of fulfillment. The realization of irradiating technologies is possible at WWR-K research reactor that is located near of Almaty . At the reactor complex, there are the means for creation powerful irradiating devices, and quite qualified personnel having the experience of works with radioactive materials is available. All of it allows, both for the staff and for the population living nearby, to have the radiation safety during of caring out of the work with the use of high intensive radioactive sources. Technical problems. The creation of plant has the following stages: - fulfilling of the calculation and design work; - caring out of mechanical works on manufacturing the irradiating devices, cartridges for irradiating sources and a hermetic tank for irradiated objects; - installation of devices, fulfilling of the tests; - purchasing or manufacturing of radioactive sources (-10-60); - loading of the sources into devices, and realization of measurements of the fields of gamma field inside the container; - making up the working instruction; - training of the personnel

Neutronic Modelling in Support of the Irradiation Programmes

International Nuclear Information System (INIS)

Koonen, E.

2005-01-01

Irradiation experiments are generally conducted to determine some specific characteristics of the concerned fuels and structural materials under well defined irradiation conditions. For the determination of the latter the BR2 division has an autonomous reactor physics cell and has implemented the required computational tools. The major tool used is a three-dimensional full-scale Monte Carlo model of the BR2 reactor developed under MCNP-4C for the simulation of irradiation conditions. The objectives of work performed by SCK-CEN are to evaluate and adjust irradiation conditions by adjustments of the environment, differential rod positions, axial and azimuthal positioning of the samples, global power level, ...; to deliver reliable, well defined irradiation condition and fluence data during and after irradiation; to assist the designer of new irradiation devices by simulations and neutronic optimisations of design options; to provide computational support to related projects as a way to valorise the capabilities that the BR2 reactor can offer

Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range

Energy Technology Data Exchange (ETDEWEB)

Canada, J.; Maj, A. [Departamento de Termodinamica Aplicada, Universidad Politecnica de Valencia, Camino de Vera, s/n. 46022 Valencia (Spain); Utrillas, M.P.; Martinez-Lozano, J.A.; Pedros, R.; Gomez-Amo, J.L. [Departamento de Fisica de la Tierra y Termodinamica, Facultat de Fisica, Universitat de Valencia, 46100 Burjassot (Valencia) (Spain)

2007-10-15

An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectro radiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330-1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth. (author)

Guidelines for acceptance of food irradiation

International Nuclear Information System (INIS)

1987-09-01

The purpose of the meeting was to develop an action plan which can be applied in countries with varying philosophies towards food irradiation, but which would help foster a common international attitude to what is undoubtedly a controversial issue. Basic recommendations were to: Identify target groups which influence policy in regard to food irradiation; Establish a cohesive marketing strategy with flexibility to meet varied national needs; Implement an ongoing communications system designed to reach and inform decision-makers; Work in each country through an information ''chain'' commencing with irradiation processors; Promote to - and through - the food industry as potentially the greatest beneficiaries; Set up an administrative ''Clearing House'' in each country to co-ordinate promotion efforts; Assemble ''Seeding Groups'' who will contact and communicate with other organizations; Aim for common international branding and packaging identification for irradiated foods

Food preservation by irradiation

International Nuclear Information System (INIS)

Kooij, J. van

1981-01-01

Twenty-five years of development work on the preservation of food by irradiation have shown that this technology has the potential to reduce post-harvest losses and to produce safe foods. The technological feasibility has been established but general acceptance of food irradiation by national regulatory bodies and consumers requires attention. The positive aspects of food preservation by irradiation include: the food keeps its freshness and its physical state, agents which cause spoilage (bacteria, etc.) are eliminated, recontamination does not take place, provided packaging materials are impermeable to bacteria and insects. It inhibits sprouting of root crops, kills insects and parasites, inactivates bacteria, spores and moulds, delays ripening of fruit, improves the technological properties of food. It makes foods biologically safe, allows the production of shelf-stable foods and is excellent for quarantine treatment, and generally improves food hygiene. The dose ranges needed for effective treatment are given

Spent fuel working group report on inventory and storage of the Department's spent nuclear fuel and other reactor irradiated nuclear materials and their environmental, safety and health vulnerabilities

International Nuclear Information System (INIS)

1993-11-01

In a memo dated 19 August 1993, Secretary O'Leary assigned the Office of Environment, Safety and Health the primary responsibility to identify, characterize, and assess the safety, health, and environmental vulnerabilities of the DOE's existing storage conditions and facilities for the storage of irradiated reactor fuel and other reactor irradiated nuclear materials. This volume is divided into three major sections. Section 1 contains the Working Group Assessment Team reports on the following facilities: Hanford Site, INEL, SRS, Oak Ridge Site, West Valley Site, LANL, BNL, Sandia, General Atomics (San Diego), Babcock ampersand Wilcox (Lynchburg Technology Center), and ANL. Section 2 contains the Vulnerability Development Forms from most of these sites. Section 3 contains the documents used by the Working Group in implementing this initiative

Irradiation of ready made meals -Lasagne

International Nuclear Information System (INIS)

Barkia, Ines

2007-01-01

The effect of ionizing radiation on the microbiological, nutritional, chemical and sensory quality of chilled ready-made meals was assessed. The ready meals used for this experimental work are lasagne. Following arrival at the semi-industrial Cobalt 60 irradiation facility, the meals were either left unirradiated or irradiated with doses of 2 or 4 kGy after which they were stored for up to 23 days at 3C. Results showed that 2 or 4 kGy doses of gamma irradiation decreased the total counts of mesophilic aerobic bacteria and increased the shelf-life of lasagne. In terms of nutritional quality, it was found that losses of vitamin A and E due to irradiation treatment were considerable at 4 kGy. Total acidity, and p H, were all well within the acceptable limit for up to one week for ready meals treated with 2 and 4 kGy whereas peroxide index showed high values at 4 kGy. Sensory results showed no significant differences between the non-irradiated and irradiated meals at 2 kGy. However, the results were less promising at 4 kGy since differences were significant. (Author). 60 refs

Detection of irradiated spice in blend of irradiated and un-irradiated spices using thermoluminescence method

International Nuclear Information System (INIS)

Goto, Michiko; Yamazaki, Masao; Sekiguchi, Masayuki; Todoriki, Setsuko; Miyahara, Makoto

2007-01-01

Five blended spice sample were prepared by mixing irradiated and un-irradiated black pepper and paprika at different ratios. Blended black pepper containing 2%(w/w) of 5.4 kGy-irradiated black pepper showed no maximum at glow1. Irradiated black pepper samples, mixed to 5 or 10%(w/w), were identified as 'irradiated' or 'partially irradiated' or 'un-irradiated'. All samples with un-irradiated pepper up to 20%(w/w) were identified as irradiated'. In the case 5.0 kGy-irradiated paprika were mixed with un-irradiated paprika up to 5%(w/w), all samples were identified as irradiated'. The glow1 curves of samples, including irradiated paprika at 0.2%(w/w) or higher, exhibited a maximum between 150 and 250degC. The results suggest the existence of different critical mixing ratio for the detection of irradiation among each spices. Temperature range for integration of the TL glow intensity were compared between 70-400degC and approximate 150-250degC, and revealed that the latter temperature range was determined based on the measurement of TLD100. Although TL glow ratio in 150-250degC was lower than that of 70-400degC range, identification of irradiation was not affected. Treatment of un-irradiated black pepper and paprika with ultraviolet rays had no effect on the detection of irradiation. (author)

Helium retention in krypton ion pre-irradiated nanochannel W film

Science.gov (United States)

Qin, Wenjing; Ren, Feng; Zhang, Jian; Dong, Xiaonan; Feng, Yongjin; Wang, Hui; Tang, Jun; Cai, Guangxu; Wang, Yongqiang; Jiang, Changzhong

2018-02-01

Nanochannel tungsten (W) film is a promising candidate as an alternative to bulk W for use in fusion applications. In previous work it has been shown to have good radiation resistance under helium (He) irradiation. To further understand the influence of the irradiation-induced displacement cascade damage on helium retention behaviour in a fusion environment, in this work, nanochannel W film and bulk W were pre-irradiated by 800 keV Kr2+ ions to the fluence of 2.6  ×  1015 ions cm-2 and subsequently irradiated by 40 keV He+ ions to the fluence of 5  ×  1017 ions cm-2. The Kr2+ ion pre-irradiation greatly increases helium retention in the form of small clusters and retards the formation of large clusters. It can effectively inhibit surface helium blistering under high temperature annealing. Compared with bulk W, no cracks were found in the nanochannel W film post-irradiated by He+ ions at high fluence. The release of helium from the nanochannel W film is more than one order of magnitude higher than that of bulk W whether they are irradiated by single He+ ions or sequentially irradiated by Kr2+ and He+ ions. Moreover, swelling of the bulk W is more serious than that of the nanochannel film. Therefore, nanochannel W film has a higher radiation tolerance performance in the synergistic irradiation.

Irradiation's potential for preserving food

International Nuclear Information System (INIS)

Morrison, R.M.

1986-01-01

The first experimental studies on the use of ionizing radiation for the preservation of foods were published over thirty years ago (1, 2) . After a period of high expectations and perhaps exaggerated optimism a series of disappointments occurred in the late '60s .The first company specifically created to operate a food irradiation plant, Newfield Products Inc, ran into financial difficulties and had to close its potato irradiation facility in 1966. The irradiator, designed to process 15,000t of potatoes per month for inhibition of sprouting, was in operation during one season only. In 1968 the US Food an Drug Administration refused approval for radiation-sterilisation of ham and withdrew the approval it had granted in 1963 for irradiated bacon. An International Project on the Irradiation of Fruit and Fruit juices, created in 1965 at Seibersdorf, Austria, with the collaboration or 9 countries, ended with general disappointment after three years. The first commercial grain irradiator, built in the Turkish harbour town of Iskenderun by the International Atomic Energy Agency with funds from the United Nations Development Program, never received the necessary operating licence from the Turkish Government and had to be dismantled in 1968. The US Atomic Energy Commission terminated its financial support to all research programmes on food irradiation in 1970. For a number of years, little chance seemed to remain that the new process would ever be practically used. However, research and development work was continued in a number of laboratories all over the world, and it appears that the temporary setbacks now have been overcome. Growing quantities of irradiated foods are being marketed in several countries and indications are that irradiated foods will eventually be as generally accepted as are frozen, dried or heatsterilised foods

Biodegradable foam trays obtained from mixtures of non-irradiated and irradiated cassava starches

International Nuclear Information System (INIS)

Brant, A.J.C.; Naime, N.; Lugao, A.B.; Ponce, P.

2015-01-01

Biodegradable polymers, such as starch, cellulose, PHB, PLA, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging by extrusion-thermopressing process. Their formulations were based on non-irradiated and γ-irradiated starches at diverse radiation absorbed doses (kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose: 26.32% and 39.84% for the trays based on starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively. Other physicochemical properties were evaluated from the starches utilized and the trays obtained. (author)

Biodegradable foam trays obtained from mixtures of non-irradiated and irradiated cassava starches

Energy Technology Data Exchange (ETDEWEB)

Brant, A.J.C.; Naime, N.; Lugao, A.B.; Ponce, P., E-mail: thonybrant@gmail.com, E-mail: patiponce@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Biodegradable polymers, such as starch, cellulose, PHB, PLA, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging by extrusion-thermopressing process. Their formulations were based on non-irradiated and γ-irradiated starches at diverse radiation absorbed doses (kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose: 26.32% and 39.84% for the trays based on starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively. Other physicochemical properties were evaluated from the starches utilized and the trays obtained. (author)

Industrial irradiators and their radioprotection

Energy Technology Data Exchange (ETDEWEB)

Rodrigues Junior, Ary de Araujo (ed.)

2018-04-01

In this book you will learn how the gamma irradiators and accelerators for industry and research applications work and all the radioprotection safety items that should be followed when operating them. This book was written mainly for those who intend to become Radiation Safety Officers (RSO) responsible for the operation of gamma irradiators, but it is also useful to business people who plan to embark on this area or for those who are simply curious. This book is only an introduction to the subject and is far from being exhaustive. (author)

Gamma-ray spectroscopy on irradiated fuel rods

International Nuclear Information System (INIS)

Terremoto, Luis Antonio Albiac

2009-01-01

The recording of gamma-ray spectra along an irradiated fuel rod allows the fission products to be qualitatively and quantitatively examined. Among all nondestructive examinations performed on irradiated fuel rods by gamma-ray spectroscopy, the most comprehensive one is the average burnup measurement, which is quantitative. Moreover, burnup measurements by means of gamma-ray spectroscopy are less time-consuming and waste-generating than burnup measurements by radiochemical, destructive methods. This work presents the theoretical foundations and experimental techniques necessary to measure, using nondestructive gamma-ray spectroscopy, the average burnup of irradiated fuel rods in a laboratory equipped with hot cells. (author)

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

International Nuclear Information System (INIS)

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

Studies on the preservation of food by gamma irradiation

International Nuclear Information System (INIS)

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)

Dose controlled low energy electron irradiator for biomolecular films.

Science.gov (United States)

Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

2016-03-01

We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

Dose controlled low energy electron irradiator for biomolecular films

Energy Technology Data Exchange (ETDEWEB)

Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.; Tsering, Thupten [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

2016-03-15

We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

Near-term Forecasting of Solar Total and Direct Irradiance for Solar Energy Applications

Science.gov (United States)

Long, C. N.; Riihimaki, L. D.; Berg, L. K.

2012-12-01

Integration of solar renewable energy into the power grid, like wind energy, is hindered by the variable nature of the solar resource. One challenge of the integration problem for shorter time periods is the phenomenon of "ramping events" where the electrical output of the solar power system increases or decreases significantly and rapidly over periods of minutes or less. Advance warning, of even just a few minutes, allows power system operators to compensate for the ramping. However, the ability for short-term prediction on such local "point" scales is beyond the abilities of typical model-based weather forecasting. Use of surface-based solar radiation measurements has been recognized as a likely solution for providing input for near-term (5 to 30 minute) forecasts of solar energy availability and variability. However, it must be noted that while fixed-orientation photovoltaic panel systems use the total (global) downwelling solar radiation, tracking photovoltaic and solar concentrator systems use only the direct normal component of the solar radiation. Thus even accurate near-term forecasts of total solar radiation will under many circumstances include inherent inaccuracies with respect to tracking systems due to lack of information of the direct component of the solar radiation. We will present examples and statistical analyses of solar radiation partitioning showing the differences in the behavior of the total/direct radiation with respect to the near-term forecast issue. We will present an overview of the possibility of using a network of unique new commercially available total/diffuse radiometers in conjunction with a near-real-time adaptation of the Shortwave Radiative Flux Analysis methodology (Long and Ackerman, 2000; Long et al., 2006). The results are used, in conjunction with persistence and tendency forecast techniques, to provide more accurate near-term forecasts of cloudiness, and both total and direct normal solar irradiance availability and

Comparison of several databases of downward solar daily irradiation data at ocean surface with PIRATA measurements

Science.gov (United States)

Trolliet, Mélodie; Wald, Lucien

2017-04-01

partial use of McClear and CAMS products. HelioClim-1 covers the period 1985-2005, while the others start in 2004 and are updated daily. Deviations between PIRATA measurements and estimates were computed and summarized by usual statistics. Biases and root mean square errors differ from one database to the other. As a whole, the correlation coefficients are large, meaning that each database reproduces the day-to-day changes in irradiation well. These good results will support the development of a satellite-derived database of daily irradiation created by MINES ParisTech within the HelioClim project. The size of the cells will be 0.25°. HelioClim-1 and HelioClim-3v5 will be combined yielding a period coverage of 32 years, from 1985 to 2016, thus allowing analyses of long term variability of downward shortwave solar radiation over the Atlantic Ocean.

γ-ray irradiation effect on magnetic properties of electromagnetic Fe-Si sheets

International Nuclear Information System (INIS)

Harara, W.

1994-11-01

The present work investigates the effect of γ-ray irradiation on the relative and differential magnetic permeabilities of electromagnetic steel sheets. The experimental work was carried out using transformer Fe-Si (97-3%) sheets. The sheets have two different forms E and I> The magnetic field dependence on the relative permeability as well as on the differential permeability before and after irradiation were measured. The measurements show that the relative permeability values of the sheets after irradiation in the region of rotation of magnetization domains were decreased whereas the value of their differential permeability around each working point remains unchangeable. (author). 7 refs., 14 figs., 6 tabs

Review of recent irradiation-creep results

International Nuclear Information System (INIS)

Coghlan, W.A.

1982-05-01

Materials deform faster under stress in the presence of irradiation by a process known as irradiation creep. This phenomenon is important to reactor design and has been the subject of a large number of experimental and theoretical investigations. The purpose of this work is to review the recent experimental results to obtain a summary of these results and to determine those research areas that require additional information. The investigations have been classified into four subgroups based on the different experimental methods used. These four are: (1) irradiation creep using stress relaxation methods, (2) creep measurements using pressurized tubes, (3) irradiation creep from constant applied load, and (4) irradiation creep experiments using accelerated particles. The similarity and the differences of the results from these methods are discussed and a summary of important results and suggested areas for research is presented. In brief, the important results relate to the dependence of creep on swelling, temperature, stress state and alloying additions. In each of these areas new results have been presented and new questions have arisen which require further research to answer. 65 references

Silicon/HfO2 interface: Effects of proton irradiation

International Nuclear Information System (INIS)

Maurya, Savita; Radhakrishna, M.

2015-01-01

Substrate oxide interfaces are of paramount importance in deciding the quality of the semiconductor devices. In this work we have studied how 200 keV proton irradiation affects the interface of a 13 nm thick, atomic layer deposited hafnium dioxide on silicon substrate. Pre- and post-irradiation electrical measurements are used to quantify the effect of proton irradiation for varying electrode geometries. Proton irradiation introduces positive charge in the oxide and at the interface of Si/HfO 2 interface. The gate current is not very much affected under positive injection since the induced positive charge is compensated by the injected electrons. Current voltage characteristics under negative bias get affected by the proton irradiation

DNA damage caused by UV- and near UV-irradiation

International Nuclear Information System (INIS)

Ohnishi, Takeo

1986-01-01

Much work with mutants deficient in DNA repair has been performed concerning UV-induced DNA damage under the condition where there is no artificial stimulation. In an attempt to infer the effects of solar wavelengths, the outcome of the work is discussed in terms of cellular radiation sensitivity, unscheduled DNA synthesis, and mutation induction, leading to the conclusion that some DNA damage occurs even by irradiation of the shorter wavelength light (270 - 315 nm) and is repaired by excision repair. It has been thought to date that pyrimidine dimer (PD) plays the most important role in UV-induced DNA damage, followed by (6 - 4) photoproducts. As for DNA damage induced by near UV irradiation, the yield of DNA single-strand breaks and of DNA-protein crosslinking, other than PD, is considered. The DNA-protein crosslinking has proved to be induced by irradiation at any wavelength of UV ranging from 260 to 425 nm. Near UV irradiation causes the inhibition of cell proliferation to take place. (Namekawa, K.)

TOA Radiation Balance Study through Reprocessed ERBS WFOV Nonscanner data from 1985 to 1998

Science.gov (United States)

Shrestha, A. K.; Kato, S.; Wong, T.; Stackhouse, P. W., Jr.; Doelling, D. R.; Loughman, R. P.

2017-12-01

Wide-field-of-view (WFOV) nonscanner instrument onboard Earth Radiation Budget Satellite (ERBS) provided broadband irradiances at the top-of-atmosphere (TOA) from 1985 to 1999. However, earlier studies show that the uncertainty in this TOA radiation dataset is significantly higher during the period after the Mt. Pinatubo eruption and battery issue in 1991. In addition, the difference between daytime and nighttime longwave irradiance drifts with time throughout the lifetime of the instrument. We re-processed ERBS WFOV data using the algorithm similar to the one used in the CERES project and calibrated it with CERES-derived irradiances. In addition, the spatial coverage of ERBS irradiances is extended to global from near-global (60°N to 60°S latitudes) using CERES climatological ratio of the near-global to global mean irradiances. The near-global standard deviation of deseasonalized shortwave anomalies computed with Ed4 decreases to 3.2 Wm-2 from 8.0 Wm-2, computed with previous version. In addition, the drift of day-minus-night longwave irradiance is reduced by one third. Similar to the previous version, however, the Ed4 global shortwave irradiance averaged over the 1994 to 1997 period (second period) is smaller by 2.2 Wm-2 compared to that averaged over the 1985 to 1989 period (first period). In addition, the global longwave irradiance in the second period is larger by 0.7 Wm-2 compared to that averaged over the first period. When the difference of two periods is computed (second period minus first period) with the DEEP-C data product (Allan et al. 2014), the difference is 0.5 (-0.3) Wm-2 for shortwave (longwave). The global net imbalance at the TOA computed with ERBS and DEEP-C data sets are, respectively, 0.45 (1.89) Wm-2 and 0.17 (0.96) Wm-2 for the first (second) period. The net imbalance for the CERES period in the 2000s is 0.65 Wm-2. In this presentation, we will further compare Ed4 ERBS-derived TOA net imbalance with ocean heating rates. Re-processed ERBS

Electron beam irradiation of simulated diluted sulfurous off-gases from copper smelters

International Nuclear Information System (INIS)

Villanueva, L.; Ahumada, L.; Chmielewski, A.G.; Zimek, Z.; Bulka, S.; Licki, J.

1998-01-01

An experimental work for the verification of potential use of electron-beam irradiation processing for S O 2 removal from reduced-S O 2 -strength gases, between 1,000 and 10,000 ppm, was conducted in a laboratory unit equipped with a multi-purpose electron accelerator working with beam energy of 800 keV. During experimental tests performed, influence of different operating parameters on the overall S O 2 removal process was established. Tests were conducted under two main conditions, using only electron beam irradiation and using electron beam irradiation plus ammonia injection. Tests results proved the technical feasibility to move S O 2 from off-gases under working experimental conditions, i.e., S O 2 removal is achieved under the two modes of operation. When using only electron beam irradiation S O 2 removal efficiencies found were rather low, up to 40%, but in the case of using electron beam irradiation in conjunction with ammonia injection, it was found that S O 2 removal efficiency raises up to 85% under experimental conditions. (author)

Radiation damage of uranium-thorium oxide, irradiated in water

International Nuclear Information System (INIS)

Bloem, P.J.C.; Nagel, W.; Plas, T. van der; Kema, N.V.

1977-01-01

A suspension in water of spherical particles of UO 2 -ThO 2 with diameter 5μm has been considered as the working fluid in an aqueous, homogeneous, thermal nuclear reactor. Irradiation experiments have shown that these particles suffer a gradual breakdown when irradiated in water. This behaviour is markedly different from that shown on irradiation in absence of water. As damage was defined the amount of solid dissolved by an etching liquid. Electron microscopic pictures showed that at higher irradiation temperatures in water the actual damage was larger than the etching values indicated. (orig.) [de

Preservation by Irradiation of three varieties of Colombian Potatoes (Solanum Tuberosum L.)

International Nuclear Information System (INIS)

Zuleta, S.

1986-01-01

This is first study performed in the Gamma Facility of the Instituto de Asuntos Nucleares, in Bogota, Colombia, related to the Food Irradiation Programme. The study was made with: Parda Pastusa, ICA Guantiva, and ICA Purace, selected as the most important varieties of colombian potatoes. A complete study prior to the irradiation exposure was made in order to determine the optimum irradiation package. Different dose treatments, chemical and physical changes and organoleptic tests, were studied in this work. The work was performed in the early 1980s

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Bonetti, Franco C.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Biologia Molecular]. E-mail: fbonetti@usp.br; Andrade Junior, Heitor Franco de [Instituto de Medicina Tropical de Sao Paulo, SP (Brazil). Lab. de Protozoologia

2005-07-01

Leishmania spp. causes a spectrum of human diseases, ranging from self-healing skin lesions to severe and lethal visceral disease. In previous work we demonstrated that the protein and nucleic acid metabolism and oxidative respiration were severely affected by irradiation, in a dose response way, but a small but representative fractions are relatively radio resistant, surviving after 800 Gy of {sup 60}Co irradiation. The best explanation could be a selection of metacyclic promastigotes. In these forms, the G0 state allows the adequate correction of DNA repair after the irradiation insult. In this work, we are looking for the ideal radiation dose to select the higher proportion of metacyclic forms of L.. (L.) amazonensis in culture. Parasites were grown in RPMI 1640 medium, plus 20% fetal calf serum, than they were irradiated with different doses ranging between 25 and 400 Gy. Parasites irradiated at 400 Gy infected, proportionally, more cells than parasites irradiated at other doses. To confirm this metacyclogenesis, a complement lysis assay was performed with 5, 10 and 20% of male guinea pig blood serum at 20 deg C for 3 hours, and parasites counted. Guinea pig serum a 10% promotes more lysis, with 200 Gy irradiated parasites being less affected, probably due to metacyclic selection. These preliminary results suggests that the ionizing radiation, specially between 200 and 400 Gy, could be a alternative tool for the selection of metacyclic forms of Leishmania amazonensis in culture. (a0011uth.

Metacyclic promastigotes of Leishmania amazonensis selection using gamma irradiation

International Nuclear Information System (INIS)

Bonetti, Franco C.; Nascimento, Nanci do; Andrade Junior, Heitor Franco de

2005-01-01

Leishmania spp. causes a spectrum of human diseases, ranging from self-healing skin lesions to severe and lethal visceral disease. In previous work we demonstrated that the protein and nucleic acid metabolism and oxidative respiration were severely affected by irradiation, in a dose response way, but a small but representative fractions are relatively radio resistant, surviving after 800 Gy of 60 Co irradiation. The best explanation could be a selection of metacyclic promastigotes. In these forms, the G0 state allows the adequate correction of DNA repair after the irradiation insult. In this work, we are looking for the ideal radiation dose to select the higher proportion of metacyclic forms of L.. (L.) amazonensis in culture. Parasites were grown in RPMI 1640 medium, plus 20% fetal calf serum, than they were irradiated with different doses ranging between 25 and 400 Gy. Parasites irradiated at 400 Gy infected, proportionally, more cells than parasites irradiated at other doses. To confirm this metacyclogenesis, a complement lysis assay was performed with 5, 10 and 20% of male guinea pig blood serum at 20 deg C for 3 hours, and parasites counted. Guinea pig serum a 10% promotes more lysis, with 200 Gy irradiated parasites being less affected, probably due to metacyclic selection. These preliminary results suggests that the ionizing radiation, specially between 200 and 400 Gy, could be a alternative tool for the selection of metacyclic forms of Leishmania amazonensis in culture. (author)

Food Irradiation Newsletter. V. 12, no. 1

International Nuclear Information System (INIS)

1988-04-01

This Newsletter reports summaries of work carried out in the past year. A coordinated research programme on ''Use of Irradiation to Control Infectivity of Food-borne Parasites'' was implemented in early 1987. The first Research Coordination Meeting of this programme was held in Poznan, Poland, August 1987 and its report is included. Another important development is ''Food Irradiation Plant: Project Profile'' of the International Finance Corporation (IFC), a subsidiary of the World Bank. IFC is in principle ready to finance installations on food irradiation facilities in developing countries provided that the proposals are submitted through Governmental channels. Details on developing such proposals for possible funding by IFC are included. This issue also contains a supplement, an up-dated list of clearance of irradiated foods. Refs, 1 fig., 1 tab

Modification of polycrystalline copper by proton irradiation

International Nuclear Information System (INIS)

Garcia S, F.; Cabral P, A.; Saniger B, J.M.; Banuelos, J.G.; Barragan V, A.

1997-01-01

Polished copper samples were irradiated with proton beams of 300 and 700 keV at room temperature and at -150 Centigrade. In this work the obtained results are reported when such copper irradiated samples are analysed with Sem, Tem, AFM. The Sem micrographs showed evident changes in surface of these copper samples, therefore an EDAX microanalysis was done for its characterization. additionally, the Tem micrographs showed heaps formation until 200 nm. Its electron diffraction spectra indicated that these heaps consist of a copper compound. Finally with AFM were observed changes in coloration of the irradiated sample surface, as well as changes in texture and rugosity of them. These results show in general that irradiation process with protons which is known as an innocuo process produces changes in the copper properties. (Author)

Sewage sludge disinfection by irradiation (ENEA-ACEA collaboration)

International Nuclear Information System (INIS)

Baraldi, D.

1997-01-01

The Municipal Association for Electricity and Water (ACEA) of Rome and the Lazio Regional Administration are implementing a programme of intervention aimed at protecting the water quality of the hydrogeological basin of Lake Bracciano. With support from ENEA, a pilot plant is being constructed for sewage-sludge direction by irradiation with accelerated electrons, in order to use the sludge as a fertilizer for agriculture, as is practised abroad mainly in Germany and the United States. The work to be carried out within the ENEA-ACEA agreement includes: sludge digestion, drying, and sterilization by irradiation. Results achieved so far, including preliminary analyses of irradiated sludge, are presented. The irradiation plant and processes involved are also described. (author)

EPR of alanine irradiated by neutrons

International Nuclear Information System (INIS)

Pivovarov, S.P.; Seredavina, T.A.; Zhdanov, S.V.; Mul'gin, S.I.; Zhakparov, R.K.

2001-01-01

In the work the first results of EPR studies of alanine, irradiated with diverse doses at neutron cyclotron generator different conditions and on the critical reactor stand are presented. A dose linearity dependence of EPR signal is observing, the methods of γ-background contribution separation are discussed. Obtain results is giving the basis to recommendation of alanine as an effective detector irradiation. However it is demanded the farther study on clarification of radiation sensitivity value dependence on the neutron energy spectrum form

Utilization of half-embryo test to identify irradiated beans

International Nuclear Information System (INIS)

Villavicencio, Anna Lucia C.H.; Mancini-Filho, Jorge

1996-01-01

Germination tests were carried out in irradiated and non-irradiated bean seeds which allow to observe characteristically variations on the shoots and roots. The methodology used in this work, is based upon biological changes which occur in two Brazilian beans, Phaseolus vulgaris L., var. carioca and Vigna unguiculata (L.) Walp, var. macacar, irradiated in a 60 Co source, with doses of 0,0.5, 1.0, 2.5, 5.0 and 10.0 kGy. The shoots and roots were observed during 3 days of culturing period under specified conditions. The differences observed in these two varieties were analysed immediately after irradiation and after 6 months of storage period at room temperature. Irradiated half-embryos showed markedly reduced root grow and almost totally retarded shoot elongation. Differences between irradiated and nonirradiated half-embryo could be observed after irradiation when different beans and storage time were varied. The shoots of half-embryos irradiated with more than 2.5 kGy did not undergo any elongation, whereas, the shoots of non-irradiated or those beans irradiated under 1.0 kGy elongated significantly within the 3 day test period. (author)

Validation of gamma irradiator controls for quality and regulatory compliance

International Nuclear Information System (INIS)

Harding, R.B.; Pinteric, F.J.A.

1995-01-01

Since 1978 the U.S. Food and Drug Administration (FDA) has had both the legal authority and the Current Good Manufacturing Practice (CGMP) regulations in place to require irradiator owners who process medical devices to produce evidence of Irradiation Process Validation. One of the key components of Irradiation Process Validation is the validation of the irradiator controls. However, it is only recently that FDA audits have focused on this component of the process validation. What is Irradiator Control System Validation? What constitutes evidence of control? How do owners obtain evidence? What is the irradiator supplier's role in validation? How does the ISO 9000 Quality Standard relate to the FDA's CGMP requirement for evidence of Control System Validation? This paper presents answers to these questions based on the recent experiences of Nordion's engineering and product management staff who have worked with several US-based irradiator owners. This topic - Validation of Irradiator Controls - is a significant regulatory compliance and operations issues within the irradiator suppliers' and users' community. (author)

A hierarchical classification approach for recognition of low-density (LDPE) and high-density polyethylene (HDPE) in mixed plastic waste based on short-wave infrared (SWIR) hyperspectral imaging

Science.gov (United States)

Bonifazi, Giuseppe; Capobianco, Giuseppe; Serranti, Silvia

2018-06-01

The aim of this work was to recognize different polymer flakes from mixed plastic waste through an innovative hierarchical classification strategy based on hyperspectral imaging, with particular reference to low density polyethylene (LDPE) and high-density polyethylene (HDPE). A plastic waste composition assessment, including also LDPE and HDPE identification, may help to define optimal recycling strategies for product quality control. Correct handling of plastic waste is essential for its further "sustainable" recovery, maximizing the sorting performance in particular for plastics with similar characteristics as LDPE and HDPE. Five different plastic waste samples were chosen for the investigation: polypropylene (PP), LDPE, HDPE, polystyrene (PS) and polyvinyl chloride (PVC). A calibration dataset was realized utilizing the corresponding virgin polymers. Hyperspectral imaging in the short-wave infrared range (1000-2500 nm) was thus applied to evaluate the different plastic spectral attributes finalized to perform their recognition/classification. After exploring polymer spectral differences by principal component analysis (PCA), a hierarchical partial least squares discriminant analysis (PLS-DA) model was built allowing the five different polymers to be recognized. The proposed methodology, based on hierarchical classification, is very powerful and fast, allowing to recognize the five different polymers in a single step.

Beneficial uses of nuclear byproducts/sewage sludge irradiation project. Progress report, October 1981-March 1982

International Nuclear Information System (INIS)

Zak, B.D.

1982-12-01

A cooperative agreement was made between Albuquerque and DOE during FY81 for sewage sludge irradiation in upgrading the sewage treatment facilities. Other potential sites for implementation of sludge irradiation technology were also considered. Sludge was irradiated in the SIDSS for agronomy and animal feeding experiments. Sludge was also irradiated for use on turf areas. Cooperative work was also performed on grapefruit irradiation for fruit fly disinfestation, and on irradiation of sugar cane waste (bagasse) for enhanced ruminant digestibility. Preliminary design work began on a shipping cask to accomodate WESF Cs-137 capsules. The shielding performance, steady-state thermal response, and response to specified regulatory accident sequences have been evaluated. Work has been initiated on pathogen survival and post-irradiation pathogen behavior. Agronomy field, greenhouse, and soil chemistry studies continue. Various field experiments are ongoing. The fifth year of a five-year program to evaluate the potential use of a sludge product as a range feed supplement for cows is now in its fifth year. In agricultural economics, a preliminary marketing plan has been prepared for Albuquerque

Microstructural examination of irradiated zircaloy-2 pressure tube material

International Nuclear Information System (INIS)

Srivastava, D.; Tewari, R.; Dey, G.K.; Sah, D.N.; Banerjee, S.

2005-01-01

Irradiation induced microstructural changes in Zr alloys strongly influence the creep, growth and mechanical properties of pressure tube material. Since dimensional changes and mechanical property degradation can limit the life of pressure tube, it is essential to study and develop an understanding of the microstructure produced by neutron irradiation, by examining samples taken from the irradiated components. In the present work, an effort has been made to examine, microstructure of the Zircaloy-2 pressure tube material irradiated in the Indian Pressurized Heavy Water Reactor (PHWR). The present work is a first step towards a comprehensive program of characterization of microstructure of reactor materials after irradiation to different fluence levels in power reactors. In this study, samples from a Zircaloy-2 pressure tube, which had been in operation in the high flux region of Rajasthan Atomic Power Station Unit 1, for a period for 6.77 effective full power years (EFPYs), have been prepared and examined. The samples selected from the tube are expected to have a cumulative radiation damage of about 3 dpa. Samples prepared from the off cuts of RAPS-1 pressure tubes were also studied for examining the unirradiated microstructure of the material. The samples were examined in a 200kV JEOL 2000 FX microscope. This paper presents the distinct features observed in irradiated sample and a comprehensive comparison of the microstructures of the unirradiated and irradiated material. The effect of annealing on the annihilation of the defects generated during irradiation has been also studied. The bright field micrographs revealed that microstructure of the irradiated samples was different in many respects from the microstructure of the unirradiated samples. The presence of defect structure in the form of loops etc could be seen in the irradiated sample. These loops were mostly c-type loops lying in the basal plane. The dissolution and redistribution of the precipitates were

Detection of irradiated frozen foods

International Nuclear Information System (INIS)

Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio

1998-01-01

We tried to detect whether foods were irradiated or not by the o-tyrosine method and the mtDNA method. The o-tyrosine method was applied to four kinds of meat (beef, pork, chicken and tuna). The results showed the linear relation between amount of o-tyrosine and dose (0-10 kGy). However, small amount of o-tyrosine were produced in some cases which application of the method summed to be very difficult because small difference between irradiated foods and untreated foods. Possibility of mtDNA method was investigated. Work and time for separation of mitochondria and extraction of DNA were reduced by a protease-solid phase extraction method. By PCR method, accurate mtDNA could be detected from very small amount of DNA. The irradiation effect is able to detect from 50 Gy. (S.Y.)

Engineering of electronic properties of single layer graphene by swift heavy ion irradiation

Science.gov (United States)

Kumar, Sunil; Kumar, Ashish; Tripathi, Ambuj; Tyagi, Chetna; Avasthi, D. K.

2018-04-01

In this work, swift heavy ion irradiation induced effects on the electrical properties of single layer graphene are reported. The modulation in minimum conductivity point in graphene with in-situ electrical measurement during ion irradiation was studied. It is found that the resistance of graphene layer decreases at lower fluences up to 3 × 1011 ions/cm2, which is accompanied by the five-fold increase in electron and hole mobilities. The ion irradiation induced increase in electron and hole mobilities at lower fluence up to 1 × 1011 ions/cm2 is verified by separate Hall measurements on another irradiated graphene sample at the selected fluence. In contrast to the adverse effects of irradiation on the electrical properties of materials, we have found improvement in electrical mobility after irradiation. The increment in mobility is explained by considering the defect annealing in graphene after irradiation at a lower fluence regime. The modification in carrier density after irradiation is also observed. Based on findings of the present work, we suggest ion beam irradiation as a useful tool for tuning of the electrical properties of graphene.

Chronic blood irradiation: a new approach

International Nuclear Information System (INIS)

Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.; Gillis, M.F.

1976-01-01

Extracorporeal irradiation of blood is beneficial in suppressing early rejection of renal allografts and in treating chronic lymphocytic leukemia. Previously, nearly all blood irradiation has involved brief intermittent exposures with high dose rates. The small amount of data available involving chronic irradiation suggests that doses given chronically at lower rates are more effective in suppressing graft rejection. However, no suitably portable device has been available to permit chronic irradiation. This work has been directed toward developing a fully portable irradiator. After preliminary testing of a variety of source materials, 170 Tm was selected for its favorable beta energy, low cost, and compatibility with the fabrication requirements. The body of the irradiator is cast from polyfurfuryl alcohol with subsequent high-temperature conversion to vitreous carbon. By sequential layering of the alcohol and suspending of 169 Tm 2 O 3 in the midlayer, a unit is produced without any radiation exposure and with the source material contained on both a macro and a micro scale. Exposure of the unit to reactor neutrons produces 170 Tm without activation of the vitreous carbon. A 170 Tm irradiator giving a transit dose of 16 rads (100 ml/min flow) was connected in a carotid--jugular shunt on a 20-kg goat. Lymphocyte levels decreased to about 15 percent of the preexposure level during the first week and thereafter slowly rose to about 50 percent of preexposure levels 2 months after exposure. Reciprocal skin grafts made at the end of irradiation (12 days) were rejected at 12 days on the nonirradiated control and at 24 days on the irradiated goat. These results are consistent with data reported on chronically irradiated baboons even though the dose rate for the present test was only about one-fourth that for the baboons

On the Thermal Conductivity Change of Matrix Graphite Materials after Neutron Irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Woo; Yeo, Seunghwan; Kim, Eung-Seon; Sah, Injin; Park, Daegyu; Kim, Youngjun; Cho, Moon Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In this work, the variations of the thermal conductivity of the A3-3 matrix graphite after neutron irradiation is discussed as well as of the IG-110 graphite for comparison. Neutron irradiation of the graphite specimens was carried out as a part of the first irradiation test of KAERI's coated particle fuel specimens by use of Hanaro research reactor. This work can be summarized as follows: 1) In the evaluation of the specific heat of the graphite materials, various literature data were used and the variations of the specific heat data of all the graphite specimens are observed well agreed, irrespectively of the difference in specimens (graphite and matrix graphite and irradiated and un-irradiated). 2) This implies that it should be reasonable that for both structural graphite and fuel matrix graphite, and even for the neuron-irradiated graphite, any of these specific heat data set be used in the calculation of the thermal conductivity. 3) For the irradiated A3-3 matrix graphite specimens, the thermal conductivity decreased on both directions. On the radial direction, the tendency of variation upon temperature is similar to that of unirradiated specimen, i.e., decreasing as the temperature increases. 4) In the German irradiation experiments with A3-27 matrix graphite specimens, the thermal conductivity of the un-irradiated specimen shows a decrease and that of irradiated specimen is nearly constant as the temperature increases. 5) The thermal conductivity of the irradiated IG-110 was considerably decreased compared with that of un-irradiated specimens The difference of the thermal conductivity of un-irradiated and irradiated IG-110 graphite specimens is much larger than that of un-irradiated and irradiated A3-3 matrix graphite specimens.

Crystal plasticity modeling of irradiation growth in Zircaloy-2

Science.gov (United States)

Patra, Anirban; Tomé, Carlos N.; Golubov, Stanislav I.

2017-08-01

A physically based reaction-diffusion model is implemented in the visco-plastic self-consistent (VPSC) crystal plasticity framework to simulate irradiation growth in hcp Zr and its alloys. The reaction-diffusion model accounts for the defects produced by the cascade of displaced atoms, their diffusion to lattice sinks and the contribution to crystallographic strain at the level of single crystals. The VPSC framework accounts for intergranular interactions and irradiation creep, and calculates the strain in the polycrystalline ensemble. A novel scheme is proposed to model the simultaneous evolution of both, number density and radius, of irradiation-induced dislocation loops directly from experimental data of dislocation density evolution during irradiation. This framework is used to predict the irradiation growth behaviour of cold-worked Zircaloy-2 and trends compared to available experimental data. The role of internal stresses in inducing irradiation creep is discussed. Effects of grain size, texture and external stress on the coupled irradiation growth and creep behaviour are also studied and compared with available experimental data.

Legal aspects and international implications of food irradiation

International Nuclear Information System (INIS)

Gerard, Alain.

1977-11-01

This paper reports on the status of work on food irradiation at international level, namely the IAEA/FAO/WHO Vienna recommendations, the proposed EEC directive, and the Codex alimentarius draft standards. It then deals with the legal aspects of the subject, in particular the problems concerning definitions, controls and instructions, and finally reviews the regulations for international trade in irradiated foodstuffs. (NEA) [fr

Theory of void swelling, irradiation creep and growth

International Nuclear Information System (INIS)

Wood, M.H.; Bullough, R.; Hayns, M.R.

Recent progress in our understanding of the fundamental mechanisms involved in swelling, creep and growth of materials subjected to irradiation is reviewed. The topics discussed are: the sink types and their strengths in the lossy continuum; swelling and void distribution analysis, including recent work on void nucleation; and, irradiation creep and growth of zirconium and zircaloy are taken as an example

Shortwave forcing and feedbacks in Last Glacial Maximum and Mid-Holocene PMIP3 simulations.

Science.gov (United States)

Braconnot, Pascale; Kageyama, Masa

2015-11-13

Simulations of the climates of the Last Glacial Maximum (LGM), 21 000 years ago, and of the Mid-Holocene (MH), 6000 years ago, allow an analysis of climate feedbacks in climate states that are radically different from today. The analyses of cloud and surface albedo feedbacks show that the shortwave cloud feedback is a major driver of differences between model results. Similar behaviours appear when comparing the LGM and MH simulated changes, highlighting the fingerprint of model physics. Even though the different feedbacks show similarities between the different climate periods, the fact that their relative strength differs from one climate to the other prevents a direct comparison of past and future climate sensitivity. The land-surface feedback also shows large disparities among models even though they all produce positive sea-ice and snow feedbacks. Models have very different sensitivities when considering the vegetation feedback. This feedback has a regional pattern that differs significantly between models and depends on their level of complexity and model biases. Analyses of the MH climate in two versions of the IPSL model provide further indication on the possibilities to assess the role of model biases and model physics on simulated climate changes using past climates for which observations can be used to assess the model results. © 2015 The Author(s).

Irradiation in adulthood as a new model of schizophrenia.

Directory of Open Access Journals (Sweden)

Yasuhide Iwata

Full Text Available BACKGROUND: Epidemiological studies suggest that radiation exposure may be a potential risk factor for schizophrenia in adult humans. Here, we investigated whether adult irradiation in rats caused behavioral abnormalities relevant to schizophrenia. METHODOLOGY/PRINCIPAL FINDINGS: A total dose of 15-Gy irradiation in six fractionations during 3 weeks was exposed to the forebrain including the subventricular zone (SVZ and subgranular zone (SGZ with male rats in the prone position. Behavioral, immunohistochemical, and neurochemical studies were performed three months after fractionated ionizing irradiation. Three months after fractionated ionizing irradiation, the total numbers of BrdU-positive cells in both the SVZ and SGZ zones of irradiated rats were significantly lower than those of control (sham-irradiated rats. Hyperactivity after administration of the dopaminergic agonist methamphetamine, but not the N-methyl-D-aspartate (NMDA receptor antagonist dizocilpine, was significantly enhanced in the irradiated rats although spontaneous locomotion in the irradiated rats was significantly lower than that of controls. Behavioral abnormalities including auditory sensory gating deficits, social interaction deficits, and working memory deficits were observed in the irradiated rats. CONCLUSION/SIGNIFICANCE: The present study suggests that irradiation in adulthood caused behavioral abnormalities relevant to schizophrenia, and that reduction of adult neurogenesis by irradiation may be associated with schizophrenia-like behaviors in rats.

Cooperative study of clinical benefits from use of the fully portable blood irradiator

International Nuclear Information System (INIS)

Hungate, F.P.

1994-10-01

This report looks at the clinical benefits from use of a fully portable blood irradiator, techniques developed by Pacific Northwest Laboratory. Significant accomplishments included the following: blood irradiators were successfully fabricated by PNL; irradiators were activated at the University of Missouri and quality tested at PNL; A-V shunts for irradiators were successfully fabricated in the PNL plastics shop; all activities necessary for experimental work on animals using the blood irradiators were completed

Cooperative study of clinical benefits from use of the fully portable blood irradiator

Energy Technology Data Exchange (ETDEWEB)

Hungate, F.P.

1994-10-01

This report looks at the clinical benefits from use of a fully portable blood irradiator, techniques developed by Pacific Northwest Laboratory. Significant accomplishments included the following: blood irradiators were successfully fabricated by PNL; irradiators were activated at the University of Missouri and quality tested at PNL; A-V shunts for irradiators were successfully fabricated in the PNL plastics shop; all activities necessary for experimental work on animals using the blood irradiators were completed.

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

International Nuclear Information System (INIS)

Thorseth, Trond Morten

2000-01-01

The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

Energy Technology Data Exchange (ETDEWEB)

Thorseth, Trond Morten

2000-07-01

The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

Irradiation of full size UMo plates

International Nuclear Information System (INIS)

Vacelet, H.; Lavastre, Y.; Grasse, M.; Sacristan, P.; Languille, A.

1999-01-01

An important development program for a UMo MTR fuel has been launched in France. The goal of the French working group is to develop a high performing and reprocessable fuel before the end of the US return policy. This paper is focussed on the fabrication of full-sized UMo plates with LEU (Low Enriched Enrichment) and their irradiation in OSIRIS reactor which was started on the 22nd of September. The results of the plates inspection are presented here as well as the irradiation conditions. (author)

Self-ion emulation of high dose neutron irradiated microstructure in stainless steels

Science.gov (United States)

Jiao, Z.; Michalicka, J.; Was, G. S.

2018-04-01

Solution-annealed 304L stainless steel (SS) was irradiated to 130 dpa at 380 °C, and to 15 dpa at 500 °C and 600 °C, and cold-worked 316 SS (CW 316 SS) was irradiated to 130 dpa at 380 °C using 5 MeV Fe++/Ni++ to produce microstructures and radiation-induced segregation (RIS) for comparison with that from neutron irradiation at 320 °C to 46 dpa in the BOR60 reactor. For the 304L SS alloy, self-ion irradiation at 380 °C produced a dislocation loop microstructure that was comparable to that by neutron irradiation. No voids were observed in either the 380 °C self-ion irradiation or the neutron irradiation conditions. Irradiation at 600 °C produced the best match to radiation-induced segregation of Cr and Ni with the neutron irradiation, consistent with the prediction of a large temperature shift by Mansur's invariant relations for RIS. For the CW 316 SS alloy irradiated to 130 dpa at 380 °C, both the irradiated microstructure (dislocation loops, precipitates and voids) and RIS reasonably matched the neutron-irradiated sample. The smaller temperature shift for RIS in CW 316 SS was likely due to the high sink (dislocation) density induced by the cold work. A single self-ion irradiation condition at a dose rate ∼1000× that in reactor does not match both dislocation loops and RIS in solution-annealed 304L SS. However, a single irradiation temperature produced a reasonable match with both the dislocation/precipitate microstructure and RIS in CW 316 SS, indicating that sink density is a critical factor in determining the temperature shift for self-ion irradiations.

In-situ observation of irradiation quantities using a tethered balloon

Science.gov (United States)

Becker, Ralf; Gross, Steffen; Behrens, Klaus

2014-05-01

Irradiance is a key parameter in Earth's weather and climate system. Accurate observations of the components of the radiation budget are therefore essential to create reliable time series, to analyse spatial variability and to test, validate and adapt satellite-based algorithms. This holds true for near surface measurements as well as for in-situ observations in the lower troposphere. Such measurements are difficult to realise and therefore rarely performed. A tethered balloon system manufactured by Vailsala (9 cbm) is utilised as a carrier of a radiation budget sonde operating up to 1000 m above ground. Application is limited to fair weather conditions with maximum winds of 20 km/h and visibility greater than 3 km at ground level. The experimental setup is composed of a downward and upward looking pair of Kipp&Zonen CM11 (0.305-2.8 μm) and a corresponding pair of Kipp&Zonen CG4 (4.5 - 42 μm). Instruments are categorized as WMO 'secondary standard' according to ISO9660 and can be characterised as sufficiently robust and with acceptable response time for this purpose. Instrumentation is complemented by meteorological sensors (wind, temperature, humidity) flown on a dedicated suspension close (less than 50 m distance) to radiation sonde. In-situ measurements of irradiation in flowing and turbulent air are subjected to errors due to moving platform (roll/yaw/pitch). Potential deviations to near-surface measurements are discussed and an error estimate is given. Some comparisons of results of radiative transfer calculations for simple meteorological conditions have been made so far. It can be accomplished either by referring to profiles or by evaluating time series taken at elevated levels. Profiling lacks stationarity most time of a day due to high variability of shortwave downward and thus must be interpreted carefully. First results for longwave profiles as well as evaluation of time series obtained at distinct levels above ground show good correspondence.

Thermoluminescent and impedimetric studies on irradiated foodstuffs

International Nuclear Information System (INIS)

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

Food Irradiation Newsletter. V. 10, no. 2

International Nuclear Information System (INIS)

1986-11-01

This issue reports the summary of the Task Force Meeting on the Use of Irradiation to Ensure Hygienic Quality of Food, convened by the International Consultative Group on Food Irradiation (ICGFI) in Vienna, July 1986. The full report of the final FAO/IAEA Research Co-ordination Meeting on Factors Influencing the Utilization of Food Irradiation, convened in Dubrovnik, Yugoslavia in June 1986, contains the conclusion of the work carried out under the Co-ordinated Research Programme in the past 5 years. A Regional Co-ordinated Research Programme for Latin America has been launched with a workshop convened on this subject in Piracicaba, Brazil, July 1986. Also featured is the summary report of the FAO/IAEA Seminar for Asia and the Pacific on the Practical Application of Food Irradiation convened in Shanghai, People's Republic of China, April 1986. The well-attended seminar reported on the progress and development of practical scale application of food irradiation in the region. A successful market testing of irradiated mangoes in Miami, Florida is also described. The outcome of this test is quite significant in view of the Chernobyl accident a few months before the tests. Tabs

Extended wavelength InGaAs on GaAs using InAlAs buffer for back-side-illuminated short-wave infrared detectors

International Nuclear Information System (INIS)

Zimmermann, Lars; John, Joachim; Degroote, Stefan; Borghs, Gustaaf; Hoof, Chris van; Nemeth, Stefan

2003-01-01

We conducted an experimental study of back-side-illuminated InGaAs photodiodes grown on GaAs and sensitive in the short-wave infrared up to 2.4 μm. Standard metamorphic InGaAs or IR-transparent InAlAs buffers were grown by molecular-beam epitaxy. We studied dark current and photocurrent as a function of buffer thickness, buffer material, and temperature. A saturation of the dark current with buffer thickness was not observed. The maximum resistance area product was ∼10 Ω cm2 at 295 K. The dark current above 200 K was dominated by generation-recombination current. A pronounced dependence of the photocurrent on the buffer thickness was observed. The peak external quantum efficiency was 46% (at 1.6 μm) without antireflective coating

Stored energy in irradiated silicon carbide

Energy Technology Data Exchange (ETDEWEB)

Snead, L.L.; Burchell, T.D. [Oak Ridge National Lab., TN (United States)

1997-04-01

This report presents a short review of the phenomenon of Wigner stored energy release from irradiated graphite and discusses it in relation to neutron irradiation of silicon carbide. A single published work in the area of stored energy release in SiC is reviewed and the results are discussed. It appears from this previous work that because the combination of the comparatively high specific heat of SiC and distribution in activation energies for recombining defects, the stored energy release of SiC should only be a problem at temperatures lower than those considered for fusion devices. The conclusion of this preliminary review is that the stored energy release in SiC will not be sufficient to cause catastrophic heating in fusion reactor components, though further study would be desirable.

Photoreactivation of UV-irradiated Legionella pneumophila and other Legionella species

International Nuclear Information System (INIS)

Knudson, G.B.

1985-01-01

Shortwave UV light was assessed as a feasible modality for the control of Legionnaires disease bacterium in water. The results of this study show that Legionella pneumophila and six other Legionella species are very sensitive to low doses of UV. However, all Legionella species tested effectively countered the germicidal effect of UV when subsequently exposed to photoreactivating light

Dose mapping in category I irradiators

International Nuclear Information System (INIS)

Mondal, Sandip; Shinde, S.H.; Mhatre, S.G.V.

2012-01-01

Category I irradiators such as Gamma Chambers and Blood Irradiators are compact self shielded, dry source storage gamma irradiators offering irradiation volume of few hundred cubic centimeters. In the present work, dose distribution profiles along the central vertical plane of the irradiation volume of Gamma Chamber 900 and Blood Irradiator 2000 were measured using Fricke, FBX, and alanine dosimeters. Measured dose distribution profiles in Gamma Chamber 900 differed from the typical generic dose distribution pattern whereas that in Blood Irradiator 2000 was in agreement with the typical pattern. All reagents used were of analytical reagent grade and were used without further purification. Preparation and dose estimations of Fricke and FBX were carried out as recommended. Alanine pellets were directly placed in precleaned polystyrene container having dimensions 6.5 mm o.d., 32 mm height and 3 mm wall thickness. For these dosimeters, dose measurements were made using e-scan Bruker BioSpin alanine dedicated ESR spectrometer. Specially designed perspex jigs were used during irradiation in Gamma Chamber 900 and Blood Irradiator 2000. These jigs provided the reproducible geometry during irradiation, Absorbance measurements were made using a spectrophotometer calibrated as per the recommended procedure. In Gamma Chamber 900, there is a dose distribution variation of about 34% from top to the center, 18% from center to the bottom, and 15% from center to the periphery. Such a dose distribution profile is largely deviating from the typical profile wherein 15% variation is observed from center to the periphery on all sides. Further investigation showed that there was a nonalignment in the source and sample chamber. However, in Blood Irradiator 2000, there is a dose distribution variation of about 20% from top to the center, 15% from center to the bottom, and 12% from center to the periphery. This pattern is very much similar to the typical profile. Hence it is recommended

Thyroid gland irradiations and thyroid cancers; Critical bibliographic journal; Irradiations de la thyroide et cancers thyroidiens. Revue bibliographique critique

Energy Technology Data Exchange (ETDEWEB)

Vitauxa, F. [CHI Le Raincy-Montfermeil, Faculte X. Bichat, Lab. de Biophysique, Service de Medecine Nucleaire, 93 - Le Raincy-Montfermeil (France)

2007-07-15

The large increase in the incidence of thyroid cancer among children who were mainly less than five years old at the time of the Chernobyl accident is still a major concern for endocrinologists and nuclear medicine physicians. Epidemiological studies have focused solely on iodine-131. However, past knowledge on thyroid irradiation (medical use of iodine-131, radioactive fallout on Marshall islands and the Nevada and Hanford site releases) as well as number of recent works (about low-dose irradiation) raise question on the role of other factors. It is here shown that post-Chernobyl thyroid irradiation is complex and that all factors (iodine-131, but also short lived isotopes of iodine and external irradiation) should be considered. Finally, one needs to think about some of the present medical uses of iodine-131 and especially to the treatment of hyperthyroidism in young subjects. (author)

Irradiation probe and laboratory for irradiated material evaluation

International Nuclear Information System (INIS)

Smutny, S.; Kupca, L.; Beno, P.; Stubna, M.; Mrva, V.; Chmelo, P.

1975-09-01

The survey and assessment are given of the tasks carried out in the years 1971 to 1975 within the development of methods for structural materials irradiation and of a probe for the irradiation thereof in the A-1 reactor. The programme and implementation of laboratory tests of the irradiation probe are described. In the actual reactor irradiation, the pulse tube length between the pressure governor and the irradiation probe is approximately 20 m, the diameter is 2.2 mm. Temperature reaches 800 degC while the pressure control system operates at 20 degC. The laboratory tests (carried out at 20 degC) showed that the response time of the pressure control system to a stepwise pressure change in the irradiation probe from 0 to 22 at. is 0.5 s. Pressure changes were also studied in the irradiation probe and in the entire system resulting from temperature changes in the irradiation probe. Temperature distribution in the body of the irradiation probe heating furnace was determined. (B.S.)

Chapter 2: Irradiators

Energy Technology Data Exchange (ETDEWEB)

NONE

2018-04-01

The chapter 2 presents the subjects: 1) gamma irradiators which includes: Category-I gamma irradiators (self-contained); Category-II gamma irradiators (panoramic and dry storage); Category-III gamma irradiators (self-contained in water); Category-IV gamma irradiators (panoramic and wet storage); source rack for Category-IV gamma irradiators; product transport system for Category-IV gamma irradiators; radiation shield for gamma irradiators; 2) accelerators which includes: Category-I Accelerators (shielded irradiator); Category-II Accelerators (irradiator inside a shielded room); Irradiation application examples.

Cost evaluation of irradiation system with electron accelerator

International Nuclear Information System (INIS)

Kashiwagi, M.

2003-01-01

The features of electron beam irradiation system using electron accelerator are direct energy pour into the irradiated material, no third material mixture such as catalyst, suitable for mass production and easy operation and maintenance work available. These features can bring the various applications such as cross-linking action, graft polymerization, radical polymerization and others. The selection of electron accelerator ratings is made under consideration of quality, width and thickness of irradiated material, production amount, dose required for reaction and irradiation atmosphere. Especially in a case of irradiation of wire with high insulation material such as polyethylene, the consideration of maximum thickness toward irradiation direction is necessary to avoid the discharge (Lichtenberg discharge) by charged-up electrons inside insulation material. Therefore, the acceleration voltage should be selected to make the maximum penetration larger than maximum irradiation thickness. The actual model case of estimate the irradiation cost was selected that the irradiation object was polyethylene insulated wire up to AWG no.14, irradiation amount was 5,000 km/month, necessary dose was 200 kGy, operation time was 22 d/month and 8 h/day and actual operation efficiency was considered loss time such as bobbin changing as 80%. The selected ratings of electron accelerator were acceleration voltage of 800 kV, beam current of 100 mA and irradiation width of 180 cm with irradiation pulleys stand of 60 turns x 3 lanes. The initial total cost was estimated as 3 M$(US) and operation cost was evaluated as 215 k$(US). Therefore, the irradiation cost of wire was evaluated as 0.0036 $/m. (author)

Gamma rays irradiation process on a restored painting from the XVII century

International Nuclear Information System (INIS)

Rizzo, Marcia M.; Machado, Luci D.B.; Rela, Paulo R.; Kodama, Yasko

2009-01-01

The aim of this work is to emphasize the importance of a previous study of the materials composition and behavior of any art work which will be treated by gamma radiation, as well as to use complementary procedures to prevent recontamination after the treatment, since this is a non residual method. As an example the object of study is a Peruvian painting from the 17th century, which has been restored, contaminated by mould, treated by gamma rays, put in a hermetic acrylic box and showed microorganisms growth after six years. A new treatment was performed using the same process and a complementary method using cloistering with anoxia atmosphere to prevent recontamination. Before the first irradiation the influence of irradiation process on the original painting and on the materials used in the restoration process were investigated. These data were extremely important in the decision of the use gamma irradiation again on the same art work. The results obtained allowed concluding that the irradiation with the recommended dose of 6.0 kGy (at the first time) was not sufficient to kill all the fungi specimens in the art work. On the other hand the irradiation with the dose of 6.0 kGy (at the first time) and 9.0 kGy (at the second time), according to the literature, would not damage the restored painting. (author)

Irradiation creep of solution annealed and cold worked 316 stainless steel

International Nuclear Information System (INIS)

Boutard, J.L.; Carteret, Y.; Cauvin, R.; Maillard, A.; Guerin, Y.

1983-01-01

Irradiation creep strains obtained in-pile on S.A. and C.W. 316 show a linear creep-swelling correlation, the slope of which is rather insensitive to chemical composition and elements in solid solution. The variation of SIPA component resulting only from the evolution of dislocation density and void growth cannot explain such an empirical correlation. The I-creep term has, on the other hand, the right temperature dependence and order of magnitude. (author)

Chromosomal instability in the progeny of irradiated parents

International Nuclear Information System (INIS)

Voro btsova, I.E.; Vorobyova, M.V.; Bogomazova, A.N.

1997-01-01

Genomic instability have been demonstrated in irradiated cells as the increased frequency of sporadic chromosome aberrations persisted over multiple generations of cell divisions. We found that chromosomal instability characterized as well the somatic cells of irradiated parents progeny. It means that radiation induced genomic instability can be transmitted via germ line cells. As a measure of instability the sensitivity of chromosomes to radiation was estimated. In animal experiments the irradiation of mature germ cells of male rats (dose - 4.5 Gy of X-rays) increase the frequency of chromosome aberrations induced by challenging irradiation in regenerating hepatocytes, in bone marrow cells and in fetal fibroblasts in the progeny of irradiated male rats. The chromosomal sensitivity of cultivated lymphocytes to in vitro irradiation (1.5 Gy of γ(rays 137 Cs) is increased in the children born parents undergone antitumor radiotherapy or worked as 'liquidators' of Chernobyl accident consequences before conception in comparison to the children of unexposed parents. The cytogenetic radiosensitivity of lymphocytes to irradiation in vitro is also increased in children evacuated from contaminated by radionuclides areas ('positive' control group). The increased spontaneous frequency of chromatid-type acentric was found in all group of children with irradiation history. The instability of genome of irradiated parents progeny seems could be the mechanism of these health effects. (authors)

Biochemical Studies on Camel Milk as a Radioprotector in Irradiated Rats

International Nuclear Information System (INIS)

Ali, S.E.

2008-01-01

This work, was conducted to evaluate the possible capability of camel milk, as a radioprotector in irradiated (4.0 Gy) rats. Two examinations were performed after two and four weeks post irradiation. γ-irradiation caused significant disorders in hematological, physiological parameters and liver cellular aspects. Drinking of camel milk induced no adverse effect on the tested parameters. Moreover, it minimized and ameliorated the radiation disorders

Safety margins of PWR irradiated vessels - The Chooz A issue

Energy Technology Data Exchange (ETDEWEB)

Hedin, F; Barthelet, B [Electricite de France (EDF), 75 - Paris (France); Guilleret, J C

1988-12-31

In 1986, some irradiated specimen of CHOOZ A (SENA) vessel showed a significant excess of {delta} RTNDT to former previsions. The lack of data on one of the two irradiated shells, and discrepancies between dosimeters results and available previous fluence calculations whose accuracy was questionable, cause the safety authorities to require an important complementary work program before putting again the plant on the grid after 1987 fuel reloading. These works are presented and discussed. They lead to a state that a conservative to day value of the vessel RTNDT is 64 degrees Celsius and that there is no underclad defect in the vessel wall and welds. Then the plant was allowed to restart with certitude that vessel irradiation will not impair its lifetime. (author). 4 refs.

Training manual on food irradiation technology and techniques. 2. ed.

International Nuclear Information System (INIS)

1982-01-01

The objective of the revised Training Manual is to help scientists to acquire the necessary knowledge needed for performing proper research and development work in the field of food irradiation. The Manual presents an up-to-date picture of the current state of food irradiation and reflects the important advances made in the technology of food irradiation, in the radiation chemistry of foods, in the microbiology of irradiated foods, in wholesomeness and standardization. It contains the following chapters: (1) Radionuclides and radiation; (2) Radiation detection and measurement; (3) Radiation protection; (4) Radiation chemistry; (5) Effects of radiation on living organisms; (6) Preservation of foods; (7) Radiation preservation of foods; (8) Packaging; (9) Combination processes; (10) Limitations of food irradiation; (11) Wholesomeness of irradiated foods; (12) Government regulation of irradiated foods; (13) Food irradiation facilities; (14) Commercial aspects of food irradiation; (15) Literature sources. The practical part of the Manual contains a revised and expanded series of detailed laboratory exercises in the use of ionizing radiation for food processing

Trends of solar ultraviolet irradiance at Barrow, Alaska, and the effect of measurement uncertainties on trend detection

Directory of Open Access Journals (Sweden)

G. Bernhard

2011-12-01

Full Text Available Spectral ultraviolet (UV irradiance has been observed near Barrow, Alaska (71° N, 157° W between 1991 and 2011 with an SUV-100 spectroradiometer. The instrument was historically part of the US National Science Foundation's UV Monitoring Network and is now a component of NSF's Arctic Observing Network. From these measurements, trends in monthly average irradiance and their uncertainties were calculated. The analysis focuses on two quantities, the UV Index (which is affected by atmospheric ozone concentrations and irradiance at 345 nm (which is virtually insensitive to ozone. Uncertainties of trend estimates depend on variations in the data due to (1 natural variability, (2 systematic and random errors of the measurements, and (3 uncertainties caused by gaps in the time series. Using radiative transfer model calculations, systematic errors of the measurements were detected and corrected. Different correction schemes were tested to quantify the sensitivity of the trend estimates on the treatment of systematic errors. Depending on the correction method, estimates of decadal trends changed between 1.5% and 2.9%. Uncertainties in the trend estimates caused by error sources (2 and (3 were set into relation with the overall uncertainty of the trend determinations. Results show that these error sources are only relevant for February, March, and April when natural variability is low due to high surface albedo. This method of addressing measurement uncertainties in time series analysis is also applicable to other geophysical parameters. Trend estimates varied between −14% and +5% per decade and were significant (95.45% confidence level only for the month of October. Depending on the correction method, October trends varied between −11.4% and −13.7% for irradiance at 345 nm and between −11.7% and −14.1% for the UV Index. These large trends are consistent with trends in short-wave (0.3–3.0 μm solar irradiance measured with pyranometers at NOAA

Identification of irradiated apples for phytosanitary purposes

International Nuclear Information System (INIS)

Horak, Celina I.; Di Giorgio, Marina; Kairiyama, Eulogia

2009-01-01

The irradiation treatment of fresh fruits and vegetables for phytosanitary purposes is a satisfactory alternative method to others like fumigation and cold and hot treatments. Its use is increasing in several countries, and at present its approval is under revision by the National Regulatory Authorities. To verify the control process, apart from irradiation and dosimetry certificates, National Authorities require complementary evidence to show the efficacy of this treatment, especially when the documentation is not clear. The irradiation of fresh fruits produces single and double fragmentation in the DNA molecule, which can be measured using the microgel electrophoresis of individual cell (comet assay). The purpose of this work was to evaluate if it is possible to identify the irradiated apples for phytosanitary purposes from the others that were not treated. The possibility to estimate the absorbed dose was also evaluated. The methodology was carried out on the cell suspension obtained from irradiated seed cells with incremental doses (100, 200 and 300 Gy). The irradiation treatment for phytosanitary purposes to avoid emergency of codling moth (Cydia pomonella) is 200 Gy. The fragmentation produced in the irradiated samples was proportional with the incremental doses applied. These results show that with this methodology it can be determined if the apple was irradiated or not. This comet assay is a simple, economical and interesting method that can be used, in case of necessity, by the National Authorities.

Identification of irradiated apples for phytosanitary purposes

Energy Technology Data Exchange (ETDEWEB)

Horak, Celina I. [Comision Nacional de Energia Atomica, Presb. Juan Gonzalez y Aragon No 15 B1802AYA, Ezeiza, Prov. Buenos Aires (Argentina)], E-mail: horak@cae.cnea.gov.ar; Di Giorgio, Marina [Autoridad Regulatoria Nuclear, Presb. Juan Gonzalez y Aragon No 15 B1802AYA, Ezeiza, Prov. Buenos Aires (Argentina); Kairiyama, Eulogia [Comision Nacional de Energia Atomica, Presb. Juan Gonzalez y Aragon No 15 B1802AYA, Ezeiza, Prov. Buenos Aires (Argentina)

2009-07-15

The irradiation treatment of fresh fruits and vegetables for phytosanitary purposes is a satisfactory alternative method to others like fumigation and cold and hot treatments. Its use is increasing in several countries, and at present its approval is under revision by the National Regulatory Authorities. To verify the control process, apart from irradiation and dosimetry certificates, National Authorities require complementary evidence to show the efficacy of this treatment, especially when the documentation is not clear. The irradiation of fresh fruits produces single and double fragmentation in the DNA molecule, which can be measured using the microgel electrophoresis of individual cell (comet assay). The purpose of this work was to evaluate if it is possible to identify the irradiated apples for phytosanitary purposes from the others that were not treated. The possibility to estimate the absorbed dose was also evaluated. The methodology was carried out on the cell suspension obtained from irradiated seed cells with incremental doses (100, 200 and 300 Gy). The irradiation treatment for phytosanitary purposes to avoid emergency of codling moth (Cydia pomonella) is 200 Gy. The fragmentation produced in the irradiated samples was proportional with the incremental doses applied. These results show that with this methodology it can be determined if the apple was irradiated or not. This comet assay is a simple, economical and interesting method that can be used, in case of necessity, by the National Authorities.

The Impact of Different Control Techniques of Industrial Irradiation Processing Units (Cobalt 60 Irradiator) on Maintaining Safety for Radiation and Environment

International Nuclear Information System (INIS)

Keshek, A. B.

2010-01-01

Negative results were caused by fire events inside and outside the industrial irradiation facilities by Co 60 irradiators. It included bad effects on equipment cables, electrical components, product boxes, products, fire detectors radiation detectors various radiation concrete shielding and big volumes of smoke. Big volumes of water and water spray were used to resist and to cool fire inside irradiation facilities. Flooded water was collected on the floor of the irradiation room, it tranced through maze legs to outside the main door and through the electrical tunnels casing big damage outside irradiation unit. The work show two different designs, the first system is the cleaner agent fire suppression by carbon dioxide. CO 2 containers are located outside irradiation concrete facility, and attached by special metallic pipes system. By fire detector and automatic control valves maintain CO 2 to suppress fire inside irradiation room and maintain clean agent fire suppression. The second system depend on Nuclear Regulatory commission C.F.R 10 of 2005 to prevent flooding and trance. The need to design a new system which trances the excessive water from inside irradiation room and to prevent it from escaping to outside irradiation facility during resisting fire by water curtion the excessive water is escaped from the storage pool by electrical pump; the second line will trance the excessive water outside the main building to store inside separated tank

Solar Electromagnetic Radiation Study for Solar Cycle 22: Solar Ultraviolet Irradiance, 120 to 300 NM: Report of Working Groups 2 and 3 of SOLERS 22

Science.gov (United States)

Rottman, G. J.; Cebula, R. P.; Gillotay, D.; Simon, P. A.

1996-01-01

This report summarizes the activities of Working Group 2 and Working Group 3 of the SOLax Electromagnetic Radiation Study for Solar Cycle 22 (SOLERS22) Program. The international (SOLERS22) is Project 1.2 of the Solar-Terrestrial Energy Program (STEP) sponsored by SCOSTEP, a committee of the International Council of Scientific Unions). SOLERS22 is comprised of five Working Groups, each concentrating on a specific wave-length range: WG-1 - visible and infrared, WG-2 - mid-ultraviolet (200 solar irradiance values in the specified wavelength ranges, 2) consider the evolving solar structures as the cause of temporal variations, and 3) understand the underlying physical processes driving these changes.

Optimizing the updated Goddard shortwave radiation Weather Research and Forecasting (WRF) scheme for Intel Many Integrated Core (MIC) architecture

Science.gov (United States)

Mielikainen, Jarno; Huang, Bormin; Huang, Allen H.-L.

2015-05-01

Intel Many Integrated Core (MIC) ushers in a new era of supercomputing speed, performance, and compatibility. It allows the developers to run code at trillions of calculations per second using the familiar programming model. In this paper, we present our results of optimizing the updated Goddard shortwave radiation Weather Research and Forecasting (WRF) scheme on Intel Many Integrated Core Architecture (MIC) hardware. The Intel Xeon Phi coprocessor is the first product based on Intel MIC architecture, and it consists of up to 61 cores connected by a high performance on-die bidirectional interconnect. The co-processor supports all important Intel development tools. Thus, the development environment is familiar one to a vast number of CPU developers. Although, getting a maximum performance out of Xeon Phi will require using some novel optimization techniques. Those optimization techniques are discusses in this paper. The results show that the optimizations improved performance of the original code on Xeon Phi 7120P by a factor of 1.3x.

DOE/EPA sludge irradiation technology transfer program

International Nuclear Information System (INIS)

Ahlstrom, S.B.

1980-01-01

The cesium-137 sludge irradiation program has successfully progressed through the phases of technology development and pilot plant evaluation and has entered the technology transfer phase. Initial technology transfer activities have identified a growing interest among wastewater engineers and public officials to learn more about the application of irradiation in sludge treatment. As a result, a formal technology transfer program has been developed. As a major activity of this program, it is planned that the US Department of Energy, working with the US Environmental Protection Agency, state and local governments, will support the placement of five to 10 sludge irradiators at selected wastewater treatment facilities throughout the United States. Facilities which may best benefit from this process technology are being identified. Technology transfer will be stimulated as engineers and wastewater officials become familiar with the evaluation and implementation of sludge irradiation at these sites

Low cycle fatigue of irradiated LMFBR materials

International Nuclear Information System (INIS)

Blackburn, L.D.

1976-01-01

A review of low cycle fatigue data on irradiated LMFBR materials was conducted and extensive graphical representations of available data are presented. Representative postirradiation tensile properties of annealed 304 and 316 SS are selected and employed in several predictive methods to estimate irradiated material fatigue curves. Experimental fatigue data confirm the use of predictive methods for establishing conservative design curves over the range of service conditions relevant to such CRBRP components as core former, fixed radial shielding, core barrel, lower inlet module and upper internals structures. New experimental data on fatigue curves and creep-fatigue interaction in irradiated 20 percent cold worked (CW) 316 SS and Alloy 718 would support the design of removable radial shielding and upper internals in CRBRP. New experimental information on notched fatigue behavior and cyclic stress-strain curves of all these materials in the irradiated condition could provide significant design data

Tensile properties of vanadium alloys irradiated at <430{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Chung, H.M.; Smith, D.L. [Argonne National Lab., IL (United States)

1997-08-01

Recent attention to vanadium alloys has focused on significant susceptibility to loss of work-hardening capability in irradiation experiments at <430{degrees}C. An evaluation of this phenomenon was conducted on V-Ti, V-Cr-Ti, and V-Ti-Si alloys irradiated in several conventional and helium-charging irradiation experiments in the FFTF-MOTA, HFIR, and EBR-II. Work hardening capability and uniform tensile elongation appear to vary strongly from alloy and heat to heat. A strong heat-to-heat variation has been observed in V-4Cr-4Ti alloys tested, i.e., a 500-kg heat (No. 832665), a 100-kg heat (VX-8), and a 30-kg heat (BL-47). The significant differences in susceptibility to loss of work-hardening capability from one heat to another are estimated to correspond to a difference of {approx}100{degrees}C or more in minimum allowable operating temperature (e.g., 450 versus 350{degrees}C).

Irradiation swelling in self-ion irradiated niobium

International Nuclear Information System (INIS)

Bajaj, R.; Shiels, S.A.; Hall, B.O.; Fenske, G.R.

1987-01-01

This paper presents initial results of an investigation of swelling mechanisms in a model body centered cubic (bcc) metal, niobium, irradiated at elevated temperatures (0.3 T/sub m/ to 0.6 T/sub m/) where T/sub m/ = melting point in K. The objective of this work is to achieve an understanding of the elevated temperature swelling in bcc metals, which are the prime candidate alloys and composite matrix materials for space reactor applications. Niobium was irradiated with 5.3 MeV Nb ++ ions, at temperatures ranging from 700 0 C to 1300 0 C, to a nominal dose of 50 dpa at a dose rate of 6 x 10 -3 dpas. Swelling was observed over a temperature range of 700 0 C to 1200 0 C, with a peak swelling of 7% at 900 0 C. The microstructural data, obtained from transmission electron microscopy, were compared to the predictions of the theoretical model developed during this program. A reasonable agreement was obtained between the experimental measurements of swelling and theoretical predictions by adjusting both the niobium-oxygen binding energy and the incubation dose for swelling to realistic values

Food irradiation

International Nuclear Information System (INIS)

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.)

Modelled basic parameters for semi-industrial irradiation plant design

International Nuclear Information System (INIS)

Mangussi, J.

2009-01-01

The basic parameters of an irradiation plant design are the total activity, the product uniformity ratio and the efficiency process. The target density, the minimum dose required and the throughput depends on the use to which the irradiator will be put at. In this work, a model for calculating the specific dose rate at several depths in an infinite homogeneous medium produced by a slab source irradiator is presented. The product minimum dose rate for a set of target thickness is obtained. The design method steps are detailed and an illustrative example is presented. (author)

The Influence of Irradiation Regimes on Retention Hydrogen Isotopes in Structural Materials

International Nuclear Information System (INIS)

Zaluzhnyi, A.

2007-01-01

Full text of publication follows: In the present work was investigated the influence of irradiation regimes on retention hydrogen isotopes in samples of austenitic steel during heating. The samples of studied materials were irradiated both in the reactor and by hydrogen isotopes ions of different energies and fluencies bombardment in an accelerator. Kinetic of hydrogen release from the samples worked with deuterium plasma was investigated. The following results were obtained. Heating the irradiate d samples of steel (irradiated in the reactor or by hydrogen isotopes ions bombardment), which have been kept in normal temperature during quite a long period after the irradiation, a shift of the diffusion peak of hydrogen release to higher temperatures, comparing to no irradiated samples, was observed. It means that atoms of hydrogen in the irradiated sample were caught by radiation defects, which are very effective as traps for hydrogen atoms till quite high temperatures (700 K). The worked out analysis of the received results supposes that vacancy complexes. On thermodesorption curves of hydrogen release from irradiated samples of austenitic steels a high temperature peak (900-1000 K) was observed because of dissociation of hydrogen containing compounds in micro pores. During investigations of hydrogen release from irradiated samples of austenitic steel, after it had been saturated with hydrogen plasma, abnormally big blisters were registered with cover thickness of about 1 mkm. Three peaks were observed on the thermodesorption curves of hydrogen release from irradiated samples, contained blisters. The low temperature spike (∼500 K) was showed to correspond to hydrogen release because of its resolution from blisters, where it was in molecular form. The high temperature peak (∼900 K) corresponds to hydrogen release from dissociating blisters, which contain hydrocarbons. The mechanism of abnormal blisters generation is offered. Inasmuch methane is not soluble in

Study of bixin oxidation by ionizing irradiation

International Nuclear Information System (INIS)

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)

Irradiation growth in zirconium alloys: a review

International Nuclear Information System (INIS)

Fidleris, V.

1980-09-01

The change in shape during irradiation without external stress, irradiation growth, was first discovered in uranium and later in graphite, zirconium and other core materials which exhibit anisotropic physical properties. The direction of maximum growth of metals invariably corresponds with the direction of minimum thermal expansion. In polycrystalline zirconium alloys growth is positive in the direction of maximum deformation during fabrication and in other directions it can be either positive or negative depending on the preferred orientation of grains (crystallographic texture). Growth increases gradually with temperature between 300 K and 620 K and rapidly with fluence up to about 1 x 10 25 n.m. -2 (Eμ1 MeV). At higher fluences the growth appears to saturate in annealed materials and reach a steady rate approximately proportional to dislocation density in cold-worked materials. Above 600 K both annealed and cold-worked materials have similar steady growth rates. Irradiation growth is caused by the segregation to different sinks of the vacancies and interstitials generated by irradiation, but the dominant types of sinks for each type of point defect and the mode of transport of the point defects to sinks cannot therefore be predicted theoretically. For the purpose of designing reactor core components empirical equations have been derived that can satisfactorily predict the steady state growth behaviour from texture and microstructure. (auth)

Electron irradiation effect on single crystal of niobium

International Nuclear Information System (INIS)

Otero, M.P.; Lucki, G.

1984-01-01

The effect of electron irradiation (900 KeV) on gliding dislocations of single crystal Nb with its tensile axe in the [941] orientation was observed for the in-situ deformation in a high voltage electron microscope (HVEM) at Argonne National Laboratory. The experimental was carried out by the 1 hour-electron irradiation with no stress applied. Straight dislocations actuating as sinks for the electron produced defects became helicoidal as the irradiation proceeded. Frenkel pairs were created in Nb for electron energies > = 650 KeV and, as the single vacancies do not undergo long-range migration in Nb at temperatures much below 620 K, the defects that are entrapped by the dislocations are self-interstitials produced by electron displacement. Applying the stress it was possible to observe that modified dislocations did not glide while the dislocations not affected by the irradiation are visibly in movement. This important result explains the neutron and electron-irradiation induced work-hardening effect for Nb that was previously observed. (Author) [pt

Establishment of experimental equipments in irradiation technology development building

International Nuclear Information System (INIS)

Ishida, Takuya; Tanimoto, Masataka; Shibata, Akira; Kitagishi, Shigeru; Saito, Takashi; Ohmi, Masao; Nakamura, Jinichi; Tsuchiya, Kunihiko

2011-06-01

The Neutron Irradiation and Testing Reactor Center has developed new irradiation technologies to provide irradiation data with high technical value for the resume of the Japan Materials Testing Reactor (JMTR). For the purpose to perform assembling of capsules, materials tests, materials inspection and analysis of irradiation specimens for the development of irradiation capsules, improvement and maintenance of facilities were performed. From the viewpoint of effective use of existing buildings in the Oarai research and development center, the RI application development building was refurbished and maintained for above-mentioned purpose. The RI application development building is a released controlled area, and was used as storage of experimental equipments and stationeries. The building was named 'Irradiation Technology Development Building' after it refurbished and maintained. Eight laboratories were maintained based on the purpose of use, and the installation of the experimental apparatuses was started. A basic management procedure of the Irradiation Technology Development Building was established and has been operated. This report describes the refurbish work of the RI application development building, the installation and operation method of the experimental apparatuses and the basic management procedure of the Irradiation Technology Development Building. (author)

The influence of mechanical deformation on the irradiation creep of AISI 316 stainless steel irradiated in the EBR-II and FFTF fast reactors

International Nuclear Information System (INIS)

Garner, F.A.; Gilbert, E.R.

2007-01-01

Irradiation creep of stainless steels is thought not to be very responsive to material and environmental variables. To test this perception earlier unpublished experiments conducted in the EBR-II reactor on AISI 316 have been analyzed. While swelling is dependent on the cold-work level at 400-480 o C, the post-transient irradiation creep rate, often called the creep compliance B0, is not dependent on cold-work level. If the tube reaches pressures on reactor start-up that generate above-yield stresses in unirradiated steel, then plastic strains occur prior to significant irradiation, but the post-transient strain rate is identical to that of material that did not exceed the yield stress on start-up. It is shown that both stress-free and stress-affected swelling are isotropic and that the Soderberg relationship is maintained. At temperatures above ∼540 o C thermal creep and stored energy begin to assert themselves, with creep rates accelerating with cold-work and becoming non-linear with stress. These results are in agreement with a similar study on titanium-modified 316 steel in FFTF. (author)

Marketing and Economic Analysis of Potatoes Irradiation in Egypt

International Nuclear Information System (INIS)

El-Khateeb, M.A.; El-Hayawan, H.

1999-01-01

The aim of this work is to examine the marketing, economic and financial feasibility of a project for potatoes irradiation in Egypt. The Egyptian market of potatoes was described and analyzed considering the production size distributed over several years, methods of preservation and storage, percentage of loss and cost for each method, distribution channels and packing materials. The financial and economic analysis of the establishment of a pallet conveyor unit for the irradiation of potatoes was also carried out . The following investment criteria were utilized for the commercial evaluation : benefit - cost radio , payback period, average rate of return and net present value . The results of this analysis showed that the installation of a unit for the irradiation of potatoes in Egypt would be economically viable. The unit of irradiation would decline if the irradiator is used as a multipurpose facility

Marketing and Economic Analysis of Garlic Irradiation in Egypt

International Nuclear Information System (INIS)

El-Khateeb, M.A.

2000-01-01

The aim of this work is to examine the marketing , economic and financial feasibility of a project for garlic irradiation in Egypt. The Egyptian market of garlic was described and analyzed considering the production size distributed over several years, methods of preservation and storage, percentage of loss and cost for each method and distribution channels. The financial and economic analysis of the establishment of A tote Box unit for the irradiation of garlic was also carried out. The following investment criteria were utilized for the commercial evaluation : benefit-cost ratio, payback period, average rate of return and net present value. The results of this analysis showed that the installation of a unit for the irradiation of garlic in Egypt would be economically viable. The unit cost of irradiation would decline if the irradiator is used as a multipurpose facility

Fusion neutron irradiation of Ni(Si) alloys at high temperature

International Nuclear Information System (INIS)

Huang, J.S.; Guinan, M.W.; Hahn, P.A.

1987-09-01

Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab

Fusion neutron irradiation of Ni(Si) alloys at high temperature

Energy Technology Data Exchange (ETDEWEB)

Huang, J.S.; Guinan, M.W.; Hahn, P.A.

1987-09-01

Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab.

Evaluation and public acceptance of irradiated strawberries and citrus fruits

International Nuclear Information System (INIS)

Del Mastro, Nelida L.; Kikuchi, Olivia K.; Villavicencio, Anna L.C.H.; Sabato, Susy F.; Rela, Paulo R.; Taipina, Magda S.; Mattiolo-Marchse, Sandra R.

1999-01-01

Irradiation is a physical process that can be applied to food in order to eliminate microorganisms, insects and other plagues as well as delay ripening or spoilage, thus lengthening its shelf life. In Brazil, the technique is only starting to be applied and is restricted to a few tons of dry or dehydrated food ingredients per year. Strawberry (Fragaria sp.) and citrus are usually attacked by various plagues. Both strawberry and citrus are included in the Brazilian legislation for irradiated foods. This work describes the first sensory trials of 2 varieties of strawberries and 3 varieties of citrus irradiated at IPEN. Irradiation was performed in a panoramic Co-60 source with doses ranging between 1.7 and 4 kGy. Untrained groups of panelists judged the quality of irradiated and non-irradiated control fruits. From the analysis of the results, it was concluded that there no significant differences in the characteristical properties of the fruits when they were irradiated with the doses recommended by the legislation. (author)

Use of irradiation to assure the hygienic quality of animal origin foods

International Nuclear Information System (INIS)

Luna Carbajal, P. C.

1991-01-01

Irradiation process for food preservation is a physical method comparable to heat or refrigeration and consist on the exposure of products packed or in bulk to gamma rays comming from Cobalt-60 or Cesium-137 or accelerated electrons and X rays produced by electric machines known as accelerators. Foods are exposed to this form of energy during a pre-stablished period in facilities named irradiators. At industrial level, the irradiation process requires a well stablished control to reach a good quality in the product. This quality control is carry out by means of dosimetry, a system which assures that the energy amount received by food is correct. Benefits derived of irradiation process in meat products as chicken, beef and pork as well as implications in matter of health and economics are presented in this work. Different aspects of irradiation process as a control to assure the hygienic quality, costs, different option of irradiators at industrial level, its advantages upon other processes, and its benefits at social level, are presented in this work. With respect to wholesomeness of irradiated food, main studies to strenghten that an irradiated food is safe, non toxic, do not imply microbian risks. it has the better nutritional quality, it has no radioactive remains and it is not a radioactivity inductor, in a word is an inocuous food, are presented in this study (Author)

Evolution of microstructure after irradiation creep in several austenitic steels irradiated up to 120 dpa at 320 °C

Energy Technology Data Exchange (ETDEWEB)

Renault-Laborne, A., E-mail: alexandra.renault@cea.fr [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Garnier, J.; Malaplate, J. [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Gavoille, P. [DEN-Service d' Etudes des Matériaux Irradiés, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Sefta, F. [EDF R& D, MMC, Site des Renardières, F-77818, Morêt-sur-Loing Cedex (France); Tanguy, B. [DEN-Service d' Etudes des Matériaux Irradiés, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

2016-07-15

Irradiation creep was investigated in different austenitic steels. Pressurized tubes with stresses of 127–220 MPa were irradiated in BOR-60 at 320 °C to 120 dpa. Creep behavior was dependent on both chemical composition and metallurgical state of steels. Different steels irradiated with and without stress were examined by TEM. Without stress, the irradiation produced high densities of dislocation lines and Frank loops and, depending on the type of steels, precipitates. Stress induced an increase of the precipitate mean size and density and, for some grades, an increase of the mean loop size and a decrease of their density. An anisotropy of Frank loop density or size induced by stress was not observed systematically. Dislocation line microstructure seems not to be different between the stressed and unstressed specimens. No cavities were detectable in these specimens. By comparing with the data from this work, the main irradiation creep models are discussed.

The construction of irradiated material examination facility

International Nuclear Information System (INIS)

Ro, Seung Gy; Lee, Key Soon; Herr, Young Hoi

1990-03-01

A detail design of the examination process, the hot cell facility and the annexed facility of the irradiated material examination facility (IMEF) which will be utilized to examine and evaluate physical and mechanical properties of neutron-irradiated materials, has been performed. Also a start-up work of the underground structure construction has been launched out. The project management and tasks required for the license application were duly carried out. The resultant detail design data will be used for the next step. (author)

Investigation on the effects of gamma irradiation on bitumen

International Nuclear Information System (INIS)

Mello, M.S.; Braz, D.; Motta, L.M.G.

2011-01-01

Brazil has more than 218,000 km of asphalt-paved highways. Bitumen is a generic term for natural or manufactured black or dark-colored solid, semisolid, or viscous cementitious materials that are composed mainly of high molecular weight hydrocarbons (90-95%). Several papers have shown that the irradiation process has changed the mechanical behavior in some polymers. This work aims to analyze the behavior of Brazilian irradiated Bitumen (CAP 50-70). In order to provide a preliminary evaluation, bitumen samples and cylindrical specimens of asphaltic mixture were tested. The bitumen samples were irradiated 0.1 to 300 kGy, and asphaltic mixture specimen was irradiated 5 to 300 kGy. The cylindrical asphaltic mixture specimen of 10.16 cm diameter used in this study was molded using an asphalt-aggregate mixture. The specimens were irradiated in LIN/UFRJ/Brazil using a Gamma cell Co 60 source of gamma irradiation with an applied dose rate of 29.7 Gy/min. After irradiated, the bitumen samples were subjected to penetration test and the asphaltic mixtures were subjected to indirect tensile strength test (diametral compression) for determination of the resilient modulus, according to ASTM method D 4123. The results of these experiments for each dose were compared with the control (nonirradiated). As expected, the penetration results showed that the ratio (irradiated/non-irradiated) decreases with increasing of irradiation dose for bitumen samples and the resilient modulus results showed that the ratio (irradiated/non-irradiated) increases with increasing of irradiation dose for asphaltic mixture. (author)

Characterization of blends of PP and SBS vulcanized with gamma irradiation

International Nuclear Information System (INIS)

Gonzalez, J.; Albano, C.; Candal, M.V.; Ichazo, M.N.; Hernandez, M.

2005-01-01

The present work has the objective of analyzing blends of PP with 30 wt% SBS vulcanized with gamma irradiation. In order to do so, SBS was irradiated at 10, 25 and 50 kGy with gamma rays. Results indicate that the gel fraction increases with irradiation dose, varying from 0.3% to 13.0% for the doses employed. Concerning tensile properties, it can be seen that the incorporation of SBS non-irradiated or irradiated decreases Young's modulus, while increasing elongation at break. Respect to thermal studies, it was detected that SBS decreases melting enthalpy of blends, fact that implies a decrease on crystallinity degree, being this effect more noticeable when SBS is irradiated at doses higher than 10 kGy. On the other hand, melting temperature diminishes slightly when adding SBS to PP, but does not show significant variations when SBS is irradiated. PPs MFI decreased with the addition of SBS, being the effect more notorious with irradiation dose. Finally, it can be concluded that SBS can be vulcanized by gamma irradiation, and that the crosslinking degree increases with irradiation dose

Elimination of Sitophilus oryzae (L.) by irradiation

Energy Technology Data Exchange (ETDEWEB)

Castro, Fernanda Peixoto [Exercito Brasileiro, Brasilia, DF (Brazil). Diretoria de Suprimento. Dept. Logistico]. E-mail: peixotocastro@dlog.eb.mil.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (brazil)]. E-mail: vital@ctex.eb.br

2005-07-01

Food treatment by exposure to ionizing radiation, known as food irradiation, presents several attractive features such as: leaving no residues, posing no threat to consumer health, usually causing no damage to sensory or nutritional properties and acting uniformly throughout the volume of the products. This work investigated the efficiency of irradiation for eliminating Sitophilus oryzae (L.), also known as 'the rice weevil', a small beetle frequently found in infested grains. A total of 444 individuals of Sitophilus oryzae (L.) found in corn meal and noodles supplies were irradiated with gamma ray doses of 0, 0.6, 0.9, 1.0, 1.2, 1.5 and 2.0 kGy and then visually monitored for 4 days in order to determine the number of insects still alive. The least-squares fitting method was used to determine the survival curves as functions of post-irradiation time and dose. The living fraction of the irradiated population was found to decrease exponentially with time. The results indicated that doses of 2.0, 1.5 and 0.6 kGy cause immediate death, instantaneous immobility and death of the species within one week, respectively. The findings suggest that disinfestation of Sitophilus oryzae (L.) by irradiation is an interesting option to the dangerous use of toxic chemicals. (author)

Elimination of Sitophilus oryzae (L.) by irradiation

International Nuclear Information System (INIS)

Castro, Fernanda Peixoto

2005-01-01

Food treatment by exposure to ionizing radiation, known as food irradiation, presents several attractive features such as: leaving no residues, posing no threat to consumer health, usually causing no damage to sensory or nutritional properties and acting uniformly throughout the volume of the products. This work investigated the efficiency of irradiation for eliminating Sitophilus oryzae (L.), also known as 'the rice weevil', a small beetle frequently found in infested grains. A total of 444 individuals of Sitophilus oryzae (L.) found in corn meal and noodles supplies were irradiated with gamma ray doses of 0, 0.6, 0.9, 1.0, 1.2, 1.5 and 2.0 kGy and then visually monitored for 4 days in order to determine the number of insects still alive. The least-squares fitting method was used to determine the survival curves as functions of post-irradiation time and dose. The living fraction of the irradiated population was found to decrease exponentially with time. The results indicated that doses of 2.0, 1.5 and 0.6 kGy cause immediate death, instantaneous immobility and death of the species within one week, respectively. The findings suggest that disinfestation of Sitophilus oryzae (L.) by irradiation is an interesting option to the dangerous use of toxic chemicals. (author)

Microstructure evolution of recrystallized Zircaloy-4 under charged particles irradiation

Science.gov (United States)

Gaumé, M.; Onimus, F.; Dupuy, L.; Tissot, O.; Bachelet, C.; Mompiou, F.

2017-11-01

Recrystallized zirconium alloys are used as nuclear fuel cladding tubes of Pressurized Water Reactors. During operation, these alloys are submitted to fast neutron irradiation which leads to their in-reactor deformation and to a change of their mechanical properties. These phenomena are directly related to the microstructure evolution under irradiation and especially to the formation of -type dislocation loops. In the present work, the radiation damage evolution in recrystallized Zircaloy-4 has been studied using charged particles irradiation. The loop nucleation and growth kinetics, and also the helical climb of linear dislocations, were observed in-situ using a High Voltage Electron Microscope (HVEM) under 1 MeV electron irradiation at 673 and 723 K. In addition, 600 keV Zr+ ion irradiations were conducted at the same temperature. Transmission Electron Microscopy (TEM) characterizations have been performed after both types of irradiations, and show dislocation loops with a Burgers vector belonging to planes close to { 10 1 bar 0 } first order prismatic planes. The nature of the loops has been characterized. Only interstitial dislocation loops have been observed after ion irradiation at 723 K. However, after electron irradiation conducted at 673 and 723 K, both interstitial and vacancy loops were observed, the proportion of interstitial loops increasing as the temperature is increased. The loop growth kinetics analysis shows that as the temperature increases, the loop number density decreases and the loop growth rate tends to increase. An increase of the flux leads to an increase of the loop number density and a decrease of the loop growth rate. The results are compared to previous works and discussed in the light of point defects diffusion.

Recent developments in the use of 2-alkylcyclobutanones as markers for irradiated lipid-containing foods

International Nuclear Information System (INIS)

Stewart, E.M.; Department of Agriculture for Northern Ireland, Belfast; Moore, S.; Graham, W.D.; McRoberts, W.C.; Hamilton, J.T.G.

1998-01-01

Complete text of publication follows. The use of 2-alkylcyclobutanones as markers for irradiated fat-containing foods has been well documented in the recent years. Initial development of the method concentrated on the detection of 2-dodecylcyclobutanone (2-DCB) in irradiated chicken meat with the methodology being subsequently modified to also detect 2-tetradecylcyclobutanone (2-TCB). The method has been validated by interlaboratory blind trials for chicken meat, pork and liquid whole egg, and was finally adopted as a European Standard (en1785) for the detection of irradiated fat-containing foods by the European Committee for Standardization (CEN) in 1996. Work has continued to further extend the applicability of this irradiation detection test to other fat-containing foods. Experimental work has shown that 2-DCB and 2-TCB can be used as markers for irradiated salmon meat, Camembert cheese, mango and papaya. The effects of irradiation dose and storage on the cyclobutanone concentration of Camembert cheese, mango and papaya have been studied while the effects of dose and temperature of irradiation were investigated for salmon meat. Other recent studies have included the investigation of the supercritical fluid extraction (SFE) technique as an alternative means of fat extraction from irradiated foods and, in addition, for extraction of the cyclobutanones directly from samples. Work is also progressing on the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of cyclobutanones with the view to developing a rapid screening test for irradiated fat-containing foods

Development of cutting device for irradiated fuel rod

International Nuclear Information System (INIS)

Lee, E. P.; Jun, Y. B.; Hong, K. P.; Min, D. K.; Lee, H. K.; Su, H. S.; Kim, K. S.; Kwon, H. M.; Joo, Y. S.; Yoo, K. S.; Joo, J. S.; Kim, E. K.

2004-01-01

Post Irradiation Examination(PIE) on irradiated fuel rods is essential for the evaluation of integrity and irradiation performance of fuel rods of commercial reactor fuel. For PIE, fuel rods should be cut very precisely. The cutting positions selected from NDT data are very important for further destructive examination and analysis. A fuel rod cutting device was developed witch can cut fuel rods longitudinal very precisely and can also cut the fuels into the same length rod cuts repeatedly. It is also easy to remove the fuel cutting powder after cutting works and it can extend the life time of cutting device and lower the contamination level of hot cell

Mechanical properties of Mo and TZM alloy neutron-irradiated at high temperatures

International Nuclear Information System (INIS)

Ueda, Kazukiyo; Satou, Manabu; Hasegawa, Akira; Abe, Katsunori

1997-01-01

This work reports the mechanical properties of irradiated molybdenum (Mo) and its alloy, TZM. Recrystallized and stress-relieved specimens were irradiated at five temperatures between 373 and 800degC in FFTF/MOTA to fluence levels of 6.8 to 34 dpa. Irradiation embrittlement and hardening were evaluated by three-point bend test and Vickers hardness test, respectively. Stress-relieved materials showed the enough ductility even after high fluence irradiation. The role of layered structure of stress-relieved specimen was discussed. (author)

Crack initiation behavior of neutron irradiated model and commercial stainless steels in high temperature water

Energy Technology Data Exchange (ETDEWEB)

Stephenson, Kale J., E-mail: kalejs@umich.edu; Was, Gary S.

2014-01-15

Highlights: • Environmental constant extension rate tensile tests were performed on neutron irradiated steel. • Percentage of intergranular cracking quantified the cracking susceptibility. • Cracking susceptibility varied with test environment, solute addition, and cold work. • No singular microstructural change could explain increases in cracking susceptibility with irradiation dose. • The increment of yield strength due to irradiation correlated well with cracking susceptibility. -- Abstract: The objective of this study was to isolate key factors affecting the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of eleven neutron-irradiated austenitic stainless steel alloys. Four commercial purity and seven high purity stainless steels were fabricated with specific changes in composition and microstructure, and irradiated in a fast reactor spectrum at 320 °C to doses between 4.4 and 47.5 dpa. Constant extension rate tensile (CERT) tests were performed in normal water chemistry (NWC), hydrogen water chemistry (HWC), or primary water (PW) environments to isolate the effects of environment, elemental solute addition, alloy purity, alloy heat, alloy type, cold work, and irradiation dose. The irradiated alloys showed a wide variation in IASCC susceptibility, as measured by the relative changes in mechanical properties and crack morphology. Cracking susceptibility measured by %IG was enhanced in oxidizing environments, although testing in the lowest potential environment caused an increase in surface crack density. Alloys containing solute addition of Ni or Ni + Cr exhibited no IASCC. Susceptibility was reduced in materials cold worked prior to irradiation, and increased with increasing irradiation dose. Irradiation-induced hardening was accounted for by the dislocation loop microstructure, however no relation between crack initiation and radiation hardening was found.

Explicit validation of a surface shortwave radiation balance model over snow-covered complex terrain

Science.gov (United States)

Helbig, N.; Löwe, H.; Mayer, B.; Lehning, M.

2010-09-01

A model that computes the surface radiation balance for all sky conditions in complex terrain is presented. The spatial distribution of direct and diffuse sky radiation is determined from observations of incident global radiation, air temperature, and relative humidity at a single measurement location. Incident radiation under cloudless sky is spatially derived from a parameterization of the atmospheric transmittance. Direct and diffuse sky radiation for all sky conditions are obtained by decomposing the measured global radiation value. Spatial incident radiation values under all atmospheric conditions are computed by adjusting the spatial radiation values obtained from the parametric model with the radiation components obtained from the decomposition model at the measurement site. Topographic influences such as shading are accounted for. The radiosity approach is used to compute anisotropic terrain reflected radiation. Validations of the shortwave radiation balance model are presented in detail for a day with cloudless sky. For a day with overcast sky a first validation is presented. Validation of a section of the horizon line as well as of individual radiation components is performed with high-quality measurements. A new measurement setup was designed to determine terrain reflected radiation. There is good agreement between the measurements and the modeled terrain reflected radiation values as well as with incident radiation values. A comparison of the model with a fully three-dimensional radiative transfer Monte Carlo model is presented. That validation reveals a good agreement between modeled radiation values.

Food irradiation

International Nuclear Information System (INIS)

Lindqvist, H.

1996-01-01

This paper is a review of food irradiation and lists plants for food irradiation in the world. Possible applications for irradiation are discussed, and changes induced in food from radiation, nutritional as well as organoleptic, are reviewed. Possible toxicological risks with irradiated food and risks from alternative methods for treatment are also brought up. Ways to analyze weather food has been irradiated or not are presented. 8 refs

Tensile and fracture properties of EBR-II-irradiated V-15Cr-5Ti containing helium

International Nuclear Information System (INIS)

Grossbeck, M.L.; Horak, J.A.

1986-01-01

The alloy V-15Cr-5Ti was cyclotron-implanted with 80 appM He and subsequently irradiated in the Experimental Breeder Reactor (EBR-II) to 30 dpa. The same alloy was also irradiated in the 10, 20, and 30% cold-worked conditions. Irradiation temperatures ranged from 400 to 700 0 C. No significant effects of helium on mechanical properties were found in this temperature range although the neutron irradiation shifted the temperature of transition from cleavage to ductile fracture to about 625 0 C. Ten percent cold work was found to have a beneficial effect in reducing the tendency for cleavage fracture following irradiation, but high levels (20%) were observed to reduce ductility. Still higher levels (30%) improved ductility by inducing recovery during the elevated-temperature irradiation. Swelling was found to be negligible, but precipitates - titanium oxides or carbonitrides - contained substantial cavities

Gas evolution as a rapid screening method for detection of irradiated foods

International Nuclear Information System (INIS)

Roberts, P.B.; Chambers, D.M.; Brailsford, G.W.

1996-01-01

A number of detection methods for irradiated foods are in advanced state of development. No single method is likely to be universally applicable but a battery of tests such as thermoluminescence, electron spin resonance and analysis of lipid radiolytic products may soon be available for most foods and technical uses of irradiation. Most of these proposed tests require relatively sophisticated equipment or technical skills and are often time consuming and costly. There would be value in relatively simple tests which could be used as a rapid screening system or confirmatory method. The literature on the use of radiolytic gases as a detection method is limited and this paper extends the above studies. In particular, it extends the work to frozen shellfish, for which irradiation has been used as a commercial decontaminant technique for many years, and considers the effect of storage temperature. Work on poultry is also reported as a cross-reference to earlier work and because irradiated poultry has recently been released into the US retail trade. (author)

Neutron irradiation creep in stainless steel alloys

Energy Technology Data Exchange (ETDEWEB)

Schuele, Wolfgang (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy)); Hausen, Hermann (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy))

1994-09-01

Irradiation creep elongations were measured in the HFR at Petten on AMCR steels, on 316 CE-reference steels, and on US-316 and US-PCA steels varying the irradiation temperature between 300 C and 500 C and the stress between 25 and 300 MPa. At the beginning of an irradiation a type of primary'' creep stage is observed for doses up to 3-5 dpa after which dose the secondary'' creep stage begins. The primary'' creep strain decreases in cold-worked steel materials with decreasing stress and decreasing irradiation temperature achieving also negative creep strains depending also on the pre-treatment of the materials. These primary'' creep strains are mainly attributed to volume changes due to the formation of radiation-induced phases, e.g. to the formation of [alpha]-ferrite below about 400 C and of carbides below about 700 C, and not to irradiation creep. The secondary'' creep stage is found for doses larger than 3 to 5 dpa and is attributed mainly to irradiation creep. The irradiation creep rate is almost independent of the irradiation temperature (Q[sub irr]=0.132 eV) and linearly dependent on the stress. The total creep elongations normalized to about 8 dpa are equal for almost every type of steel irradiated in the HFR at Petten or in ORR or in EBR II. The negative creep elongations are more pronounced in PCA- and in AMCR-steels and for this reason the total creep elongation is slightly smaller at 8 dpa for these two steels than for the other steels. ((orig.))

Effect of gamma irradiation on HPMC/ZnO nanocomposite films

International Nuclear Information System (INIS)

Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shivananda, C. S.; Harish, K. V.; Sangappa; Shetty, G. Rajesha

2015-01-01

The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films

Food irradiation methodology : prospect and retrospect

International Nuclear Information System (INIS)

Nadkarni, G.B.

1987-01-01

Research and development work in food irradiation over the past several years has been essentially directed towads answering all possible questions in respect of the suitability of the process, quality of materials and safety for human use. A major effort was indeed, around the toxicological evaluation, till it was recognised internationally that irradiated items of food do not present any health hazards. This recognition along with the awareness of the hazards in the use of chemicals has resulted in a renewed interest in the use of radiations for preservation of food. Radiation preservation of food would reach the stage of practical application with additional information on design and functional aspects of radiation sources, appropriate for specific commodities. Each items has a particular dose requirement depending on the purpose of irradiation and the type of handling. 21 refs. (author)

The cryogenic installations for irradiation in the reactors Melusine and Siloe; Les installations cryogeniques pour irradiations des reacteurs Melusine et Siloe

Energy Technology Data Exchange (ETDEWEB)

Bochirol, L; Le Calvez, J; Doulat, J; Verdier, J; Lacaze, A; Weil, L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

The study of defects created in solids by irradiation is of considerable fundamental and practical interest. Low temperature irradiation allows defects to be obtained in their simplest 'primary' state, not being then annihilated or rearranged by thermal motion. In-pile irradiation at low temperature raises a number of technical problems connected to 1) the necessary refrigeration power which may be considerable, 2) chemical processes which may occur under irradiation, 3) the lack of space in a reactor. Furthermore the necessity that all the irradiation and subsequent measurements be done without reheating the samples demands continuous and reliable working of the irradiation device and its being designed so as to permit removal of the samples in the cold condition or their measurement and controlled annealing 'in situ'. The way in which these problems have been solved in Grenoble for irradiation devices at 78 deg. K, 28 deg. K and 4 deg. K in the swimming-pool reactors Melusine and Siloe is described. Some operation results are given about the liquid nitrogen rig, called mark A, which has worked for several years in Melusine. In particular certain observations about chemical reactions which may occur in impure liquid nitrogen under radiation are made. The liquid nitrogen rig, called mark B, which has just been installed in the Siloe reactor, is described with some detail. The essential features of this apparatus are that irradiation can be performed in higher fluxes with it than with the former one, and that its operation is made much easier by a design which allows the samples to be introduced and removed without any disconnection of the apparatus. A liquid hydrogen loop, which has worked for one year in the Melusine reactor, is then analysed. An entirely closed hydrogen refrigerating circuit provides the coldness to the irradiation enclosure, which contains neon. Owing to this solution, the samples may be recovered in the cold condition without hydrogen being

MAFF sponsored research: detection tests for irradiated food

International Nuclear Information System (INIS)

Blackburn, C.M.; Holley, P.A.; Pryke, D.C.

1993-01-01

In their 1986 report on the safety and wholesomeness of irradiated food the UK Advisory Committee on Irradiated and Novel Foods (ACINF) recognised that a generally applicable test to determine if a food had been irradiated was not available. The committee considered that, although not a pre-requisite, the existence of a detection test would be a useful supplement to a control system and do much to reassure consumers; with this in mind ACINF recommended that detection methods should be kept under review. As a consequence, in 1987 the Ministry initiated a comprehensive R and D detection test programme. Over fifty papers have been published to date as a result of this programme. MAFF (Ministry Of Agriculture Fisheries and Food) has also been involved in other research associated with irradiation and food safety, some of which is described in this paper. This paper aims to give an overview of recent work funded under the food irradiation programme. Twelve projects have been supported over the last two years, ten of which involved the development of detection tests for irradiated food. A summary of these projects is presented: - Thermoluminescence; - Electron Spin Resonance; - 2-alkylcyclobutanones; -Determination Of Hydrogen; - Differential Scanning Calorimetry; - Limulus Amoebocyte Lysate; - DNA; - Pesticide Breakdown; - Neutron Irradiation; -Future Plans. (orig./vhe)

Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

Science.gov (United States)

Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley; Vo, Hi T.; Maloy, Stuart A.; Hosemann, Peter; Mara, Nathan A.

2017-09-01

Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current work focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless steel to quantify the mechanical effects of radiation damage. Spherical nanoindentation stress-strain measurements show a radiation-induced increase in indentation yield strength from 1.36 GPa to 2.72 GPa and a radiation-induced increase in indentation work hardening rate of 10 GPa-30 GPa. These measurements are critically compared against Berkovich nanohardness, micropillar compression, and micro-tension measurements on the same material and similar grain orientations. The ratio of irradiated to unirradiated yield strength increases by a similar factor of 2 when measured via spherical nanoindentation or Berkovich nanohardness testing. A comparison of spherical indentation stress-strain curves to uniaxial (micropillar and micro-tension) stress-strain curves was achieved using a simple scaling relationship which shows good agreement for the unirradiated condition and poor agreement in post-yield behavior for the irradiated condition. The disagreement between spherical nanoindentation and uniaxial stress-strain curves is likely due to the plastic instability that occurs during uniaxial tests but is absent during spherical nanoindentation tests.

Irradiation proctitis

International Nuclear Information System (INIS)

Minami, Akira

1977-01-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures. (Kanao, N.)

Irradiation proctitis

Energy Technology Data Exchange (ETDEWEB)

Minami, A [Osaka Kita Tsishin Hospital (Japan)

1977-06-01

Literatures on late rectal injuries are discussed, referring to two patients with uterine cervical cancer in whom irradiation proctitis occurred after telecobalt irradiation following uterine extirpation. To one patients, a total of 5000 rads was irradiated, dividing into 250 rads at one time, and after 3 months, irradiation with a total of 2000 rads, dividing into 200 rads at one time, was further given. In another one patient, two parallel opposing portal irradiation with a total of 6000 rads was given. About a year after the irradiation, rectal injuries and cystitis, accompanying with hemorrhage, were found in both of the patients. Rectal amputation and proctotoreusis were performed. Cystitis was treated by cystic irradiation in the urological department. Pathohistological studies of the rectal specimen revealed atrophic mucosa, and dilatation of the blood vessels and edema in the colonic submucosa. Incidence of this disease, term when the disease occurs, irradiation dose, type of the disease, treatment and prevention are described on the basis of the literatures.

Antecedents, actual situation and prospective of the food irradiation in Mexico

International Nuclear Information System (INIS)

Lopez V, H.; Polo C, G.; Ramirez de Alba, M.; Mayoral G, V.M.

1992-06-01

In this work a synthesis of the history of the food irradiation in Mexico is presented, as well as its current situation. In the same way the foods produced in the country that are susceptible to be irradiated are identified, with object of presenting this process as an alternative method to conserve and to improve the safety of the foods, also showing the potential of the installation of new irradiation plants. (Author)

The coordinated research project on use of irradiation to ensure the safety and quality of prepared meals. Proceedings of the 3rd FAO/IAEA research coordination meeting (RCM). Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Although extensive research has been carried out on the microbiological and sensorial effects of irradiating individual uncooked food items, little work has been reported on the irradiation of complex food systems such as prepared meals. In this Coordinated Research Project (CRP), the potential of using the irradiation technology for convenience foods has been investigated with regard to safety, shelf-life and overall quality, particularly in terms of sensory acceptance. A wide range of ethnic meals as well as meal components were investigated with the objective of meeting continual changes in consumer demands worldwide. Other aspects of the CRP included the adoption of a Hazard Analysis Critical Control Point (HACCP) system for prepared meals and research into consumer willingness to purchase irradiated food at a premium price. The scope of the CRP was therefore wide-ranging. The overall objective of this CRP was to evaluate the effectiveness of irradiation as a method to ensure the microbiological safety and extend the shelf-life of prepared meals, stored under ambient, chilled or frozen conditions, and to evaluate the sensory quality of the treated products. The specific objective of the CRP was to use validated procedures for irradiation treatment and process control, and to use validated methods for assessing microbiological safety and quality as well as the sensory quality of prepared meals mainly of ethnic origin.

The coordinated research project on use of irradiation to ensure the safety and quality of prepared meals. Proceedings of the 3rd FAO/IAEA research coordination meeting (RCM). Working material

International Nuclear Information System (INIS)

2006-01-01

Although extensive research has been carried out on the microbiological and sensorial effects of irradiating individual uncooked food items, little work has been reported on the irradiation of complex food systems such as prepared meals. In this Coordinated Research Project (CRP), the potential of using the irradiation technology for convenience foods has been investigated with regard to safety, shelf-life and overall quality, particularly in terms of sensory acceptance. A wide range of ethnic meals as well as meal components were investigated with the objective of meeting continual changes in consumer demands worldwide. Other aspects of the CRP included the adoption of a Hazard Analysis Critical Control Point (HACCP) system for prepared meals and research into consumer willingness to purchase irradiated food at a premium price. The scope of the CRP was therefore wide-ranging. The overall objective of this CRP was to evaluate the effectiveness of irradiation as a method to ensure the microbiological safety and extend the shelf-life of prepared meals, stored under ambient, chilled or frozen conditions, and to evaluate the sensory quality of the treated products. The specific objective of the CRP was to use validated procedures for irradiation treatment and process control, and to use validated methods for assessing microbiological safety and quality as well as the sensory quality of prepared meals mainly of ethnic origin

Infrared autofluorescence, short-wave autofluorescence and spectral-domain optical coherence tomography of optic disk melanocytomas

Directory of Open Access Journals (Sweden)

Peng Zhang

2016-05-01

Full Text Available AIM: To investigate the findings of infrared fundus autofluorescence (IR-AF and spectral-domain optical coherence tomography (SD-OCT in eyes with optic disc melanocytoma (ODM. METHODS: IR-AF findings and those of other ophthalmologic imaging examinations, including short-wave autofluorescence (SW-AF, fluorescein angiography (FA, fundus color photography, and SD-OCT of 8 eyes of 8 consecutive cases with ODM were assessed. RESULTS: The ODMs in all cases (100% presented similar IR-AF, SW-AF, and FA findings. On IR-AF images, ODMs showed outstanding hyper-AF with well-defined outline. On SW-AF images, the area of ODMs presented as hypo-AF. FA images revealed the leaking retinal telangiectasia on the surface of the ODMs. On SD-OCT images in 8 cases (100%, the ODMs were sloped with highly reflective surface, which were disorganized retina and optic nerve layers. In 7 cases (87.5%, peripapillary choroids were involved. The melanocytomas of 8 cases (100% presented as optically empty spaces. Vitreous seeds were found in one case (12.5%. CONCLUSION: IR-AF imaging may provide a new modality to evaluate the pathologic features of ODMs, and together with SW-AF imaging, offers a new tool to study biological characteristics associated with ODMs. SD-OCT is a valuable tool in delimitating the tumor extension and providing morphological information about the adjacent retinal tissue.

Bibliographic review of works accomplished about irradiated chicken, fish and fish products , spices and condiments; Levantamento bibliografico de trabalhos realizados sobre aves, peixes e produtos de peixe, especiarias e condimentos irradiados

Energy Technology Data Exchange (ETDEWEB)

Bernardes, B; Dias Filho, M

1983-07-01

Table of foods that can be irradiated and its respective nominal doses are shown. Bibliographic reviews of works performed about irradiated chicken, fish and fish products, spices and condiments are shown. The irradiation purpose in chicken were to increase the shelf-life and to eliminate the pathogenic microorganism in chicken stored below 10{sup 0} C; in fish and fish products the purposes were to control the insect infestation in dry-fish during the storage and the sell exposure to reduce the macrobian charge in packed and non packed fish and in fish products. To reduce pathogenic microorganism in packing and unpacking fish; in spices and condiments to control the insect infestation, to reduce the microbial contamination. (L.M.J.).

Pressure vessel steels: influence of chemical composition on irradiation sensitivity

International Nuclear Information System (INIS)

Ghoniem, M.M.; Hammad, F.H.

1998-01-01

Neutron irradiation of the steels used in the construction of the nuclear reactor pressure vessels can lead to the embrittlement of these materials, increasing the ductile-to-brittle transition temperature and decreasing the fracture energy, which can limit the plant life. The knowledge of irradiation embrittlement and the means for minimizing such degradation is therefore important in the field of assuring the safety of the nuclear power plants. Irradiation embrittlement is quite a complex process. It involves many variables. The most important of these are irradiation temperature, neutron fluence (neutron dose), neutron flux (neutron dose rate), and chemical composition of the irradiated material. This paper is concerned with the effect of chemical composition, the role of residual and alloying elements in the irradiation embrittlement of nuclear reactor pressure vessel steels in light water reactors. It presents a critical review for the published work in this field through the last 25 years

Localized irradiations, evaluation through 'Comet Assay'

International Nuclear Information System (INIS)

Di Giorgio, Marina; Taja, Maria R.; Nasazzi, Nora B.; Bustos, N.; Cavalieri, H.; Bolgiani, A.

2000-01-01

During the last 50 years various radiation accidents involving localized irradiations occurred, resulting mainly from improper handling of sealed sources of Cobalt 60, Cesium 137 or Iridium 192 at work placed for industrial gammagraphy and other radiation sources. Severe skin reaction may developed at the contact sites. Such inhomogeneous irradiations lead to a differential exposure of lymphocytes in lymphatic tissues or other organs that may recirculate into the peripheral blood producing a mixed irradiated and unirradiated population of lymphocytes. Applying the mathematical models 'Contaminated Poisson' of Dolphin and Qdr method of Sasaki, a mean dose in the irradiated body area and its size can be estimated from unstable chromosome aberration scoring. There are also different biophysical techniques that can give response in localized irradiations. Biological dosimetry is a necessary complement to physical and clinical dosimetries. Thus, there is increasing interest in the assessment of biological markers that permit the detection of radiation induced damage in the localized irradiations. The 'Comet Assay' (single cell gel electrophoresis) is a sensitive, rapid and relatively inexpensive method for measuring DNA damage in individual cells. Single cells are embedded in agarose on microscope slides, lysed to remove the majority of the proteins, electrophoresed, then stained with ethidium bromide in order to visualize the DNA. When visualized using a fluorescent microscope, DNA of undamaged cells appears as a spherical mass occupying the cavity formed by the lysed cell. Following radiation damage, the smaller the fragment size and the grater the number of fragments of DNA, the grater the percentage of DNA that it is able to migrate in an electric field, forming a comet image. The assay can be performed under alkaline conditions to examine DNA single strand breaks (SSBs), or in non denaturing (neutral) conditions to measure double strand breaks (DSBs) in individual

Study of irradiation effects in austenitic stainless steels

Energy Technology Data Exchange (ETDEWEB)

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)

Migration under irradiation of the I, Cs fission products in SiC; Migration sous irradiation des produits de fission I, Cs dans SiC

Energy Technology Data Exchange (ETDEWEB)

Benyagoub, A. [Paris-11 Univ., 91 - Orsay (France). Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse; Centre Interdisciplinaire de Recherche Ions Lasers (CIRIL), 14 - Caen (France)

2007-07-01

This work is a part of the CEA-CNRS program on the behaviour of materials under irradiation. Its aim is to contribute to scientifically base the predicting methods of the behaviour of ceramic materials under irradiation in using the important development of calculation means. In particular, its role has been 1)to develop the basic knowledge and the interactions physics and 2)to elaborate calculation models at relevant scales. The studied topics are until now, the damage mechanisms, the diffusion under irradiation, the micro-structural evolutions and the incidences on the mechanical properties. (O.M.)

Food irradiation

International Nuclear Information System (INIS)

Soothill, R.

1987-01-01

The issue of food irradiation has become important in Australia and overseas. This article discusses the results of the Australian Consumers' Association's (ACA) Inquiry into food irradiation, commissioned by the Federal Government. Issues discussed include: what is food irradiation; why irradiate food; how much food is consumer rights; and national regulations

Fatty acids changes of baby food fat by γ irradiation

International Nuclear Information System (INIS)

Aflaki, F.; Matloubi, H.; Ahmadi, M. A. A.

2005-01-01

There is a mutual protection when mixtures of components irradiated together, so experimental investigation is necessary for determination of the effects that actually occur in different class of nutrients in formulated foods. This work is concerned with the effect of γ irradiated on fatty acids content of a formulated baby food fat and the results is compared with changes of fatty acids in irradiated whole foods. Irradiation was performed with a gamma cell (Co-60) at dose levels of 0.5, 1.5, 6, 10, 30, 45 kGy at room temperature and in the presence of air. The samples were analyzed immediately after irradiation by high performance liquid chromatography. The results showed that destruction of fatty acids in this formulated food is reasonably less than fatty acids of whole foods fat

Microstructural defects in EUROFER 97 after different neutron irradiation conditions

Directory of Open Access Journals (Sweden)

Christian Dethloff

2016-12-01

Full Text Available Characterization of irradiation induced microstructural evolution is essential for assessing the applicability of structural steels like the Reduced Activation Ferritic/Martensitic steel EUROFER 97 in upcoming fusion reactors. In this work Transmission Electron Microscopy (TEM is used to determine the defect microstructure after different neutron irradiation conditions. In particular dislocation loops, voids and precipitates are analyzed concerning defect nature, density and size distribution after irradiation to 15 dpa at 300 °C in the mixed spectrum High Flux Reactor (HFR. New results are combined with previously obtained data from irradiation in the fast spectrum BOR-60 reactor (15 and 32 dpa, 330 °C, which allows for assessment of dose and dose rate effects on the aforementioned irradiation induced defects and microstructural characteristics.

Customer attitude front to the food irradiation

International Nuclear Information System (INIS)

Ornellas, Cleia Batista Dias; Goncalves, Maria Paula Junqueira; Martins, Renaldo Travassos; Silva, Patricia Rodrigues

2006-01-01

Economic and social factors as cost, availability and food habits usually influence the consumer's choice. Nowadays other factors like legislation, rising of meals eaten out-of-home and the application of new technologies have been affected the shopping decision. In this direction it is necessary to have more explanations about food irradiation as a method to conserve food. Its commercial use has been slow because most of the consumers misunderstands or has wrong belief about this technique. In such a manner, this work aimed at realizing a survey of knowledge and acceptance level of food irradiation in Belo Horizonte (MG), Brazil, and also to elucidate its real meaning to consumers. A total of 218 people were interviewed and the results showed that 59.6% of them have not known that irradiation is a method to preserve food, thus they have no idea if they consume or not this kind of food. About 16% believe that irradiated food means the same of radioactive food. Besides that, 89% of people interviewed could become consumers of this product if they know that irradiation raises the food safety. (author)

Thermal imaging of high power diode lasers subject to back-irradiance

Science.gov (United States)

Li, C.; Pipe, K. P.; Cao, C.; Thiagarajan, P.; Deri, R. J.; Leisher, P. O.

2018-03-01

CCD-based thermoreflectance imaging and finite element modeling are used to study the two-dimensional (2D) temperature profile of a junction-down broad-area diode laser facet subject to back-irradiance. By determining the temperature rise in the active region (ΔΤAR) at different diode laser optical powers, back-irradiance reflectance levels, and back-irradiance spot locations, we find that ΔΤAR increases by nearly a factor of three when the back-irradiance spot is centered in the absorbing substrate approximately 5 μm away from the active region, a distance roughly equal to half of the back-irradiance spot FWHM (9 μm). This corroborates prior work studying the relationship between the back-irradiance spot location and catastrophic optical damage, suggesting a strong thermal basis for reduced laser lifetime in the presence of back-irradiance for diode lasers fabricated on absorbing substrates.

Fusion neutron irradiation of Ni-Si alloys at high temperature*1

Science.gov (United States)

Huang, J. S.; Guinan, M. W.; Hahn, P. A.

1988-07-01

Two Ni-4% Si alloys, with different cold work levels, have been irradiated with 14-MeV fusion neutrons at 623 K, and their Curie temperatures have been monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2-MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14-MeV fusion neutrons is only 6-7% of that for an identical alloy irradiated by 2-MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6-7% for the fusion neutron irradiated sample.

RTNS-II irradiations and operations

International Nuclear Information System (INIS)

Logan, C.M.; Heikkinen, D.W.

1982-01-01

The objectives of this work are operation of RTNS-II (a 14-MeV neutron source facility), machine development, and support of the experimental program that utilizes this facility. Experimenter services include dosimetry handling, scheduling, coordination, and reporting. RTNS-II is dedicated to materials research for the fusion power program. Its primary use is to aid in the development of models of high-energy neutron effects. Such models are needed in interpreting and projecting to the fusion environment engineering data obtained in other neutron spectra. Irradiations were performed for a total of twenty-nine different experimenters during this quarter. A JOEL 200 CX TEM and other post-irradiation test equipment have been installed

Evaluation of irradiation hardening of proton irradiated stainless steels by nanoindentation

International Nuclear Information System (INIS)

Yabuuchi, Kiyohiro; Kuribayashi, Yutaka; Nogami, Shuhei; Kasada, Ryuta; Hasegawa, Akira

2014-01-01

Ion irradiation experiments are useful for investigating irradiation damage. However, estimating the irradiation hardening of ion-irradiated materials is challenging because of the shallow damage induced region. Therefore, the purpose of this study is to prove usefulness of nanoindentation technique for estimation of irradiation hardening for ion-irradiated materials. SUS316L austenitic stainless steel was used and it was irradiated by 1 MeV H + ions to a nominal displacement damage of 0.1, 0.3, 1, and 8 dpa at 573 K. The irradiation hardness of the irradiated specimens were measured and analyzed by Nix–Gao model. The indentation size effect was observed in both unirradiated and irradiated specimens. The hardness of the irradiated specimens changed significantly at certain indentation depths. The depth at which the hardness varied indicated that the region deformed by the indenter had reached the boundary between the irradiated and unirradiated regions. The hardness of the irradiated region was proportional to the inverse of the indentation depth in the Nix–Gao plot. The bulk hardness of the irradiated region, H 0 , estimated by the Nix–Gao plot and Vickers hardness were found to be related to each other, and the relationship could be described by the equation, HV = 0.76H 0 . Thus, the nanoindentation technique demonstrated in this study is valuable for measuring irradiation hardening in ion-irradiated materials

Tensile and fracture properties of EBR-II-irradiated V-15Cr-5Ti containing helium

Energy Technology Data Exchange (ETDEWEB)

Grossbeck, M.L.; Horak, J.A.

1986-01-01

The alloy V-15Cr-5Ti was cyclotron-implanted with 80 appM He and subsequently irradiated in the Experimental Breeder Reactor (EBR-II) to 30 dpa. The same alloy was also irradiated in the 10, 20, and 30% cold-worked conditions. Irradiation temperatures ranged from 400 to 700/sup 0/C. No significant effects of helium on mechanical properties were found in this temperature range although the neutron irradiation shifted the temperature of transition from cleavage to ductile fracture to about 625/sup 0/C. Ten percent cold work was found to have a beneficial effect in reducing the tendency for cleavage fracture following irradiation, but high levels (20%) were observed to reduce ductility. Still higher levels (30%) improved ductility by inducing recovery during the elevated-temperature irradiation. Swelling was found to be negligible, but precipitates - titanium oxides or carbonitrides - contained substantial cavities.

Post irradiation test report of irradiated DUPIC simulated fuel

International Nuclear Information System (INIS)

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

2001-12-01

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

Facts about food irradiation: Irradiated foods and the consumer

International Nuclear Information System (INIS)

1991-01-01

This fact sheet discusses market testing of irradiate food, consumer response to irradiated products has always been positive, and in some countries commercial quantities of some irradiated food items have been sold on a regular basis. Consumers have shown no reluctance to buy irradiated food products. 4 refs

Kinetics of phenol degradation in water solutions under gamma-irradiation

International Nuclear Information System (INIS)

Guliyeva, U.A.; Gurbanov, M.A.; Abdullayev, E.T.

2014-01-01

Full text : In this work the chemical oxygen demand and change of phenol concentration at the radiolysis of aqueous solutions of phenol was studied. Irradiation conducted under gamma-irradiation of 60Co at static conditions and at room temperature. The main component is water, therefore the radiolysis process of water plays an important role in radiolytic degradation of phenol

Therapy of infections in mice irradiated in mixed neutron/photon fields and inflicted with wound trauma: a review of current work.

Science.gov (United States)

Ledney, G D; Madonna, G S; Elliott, T B; Moore, M M; Jackson, W E

1991-10-01

When host antimicrobial defenses are severely compromised by radiation or trauma in conjunction with radiation, death from sepsis results. To evaluate therapies for sepsis in radiation casualties, we developed models of acquired and induced bacterial infections in irradiated and irradiated-wounded mice. Animals were exposed to either a mixed radiation field of equal proportions of neutrons and gamma rays (n/gamma = 1) from a TRIGA reactor or pure gamma rays from 60[Co sources. Skin wounds (15% of total body surface area) were inflicted under methoxyflurane anesthesia 1 h after irradiation. In all mice, wounding after irradiation decreased resistance to infection. Treatments with the immunomodulator synthetic trehalose dicorynomycolate (S-TDCM) before or after mixed neutron-gamma irradiation or gamma irradiation increased survival. Therapy with S-TDCM for mice irradiated with either a mixed field or gamma rays increased resistance to Klebsiella pneumoniae-induced infections. Combined therapy with S-TDCM and ceftriaxone for K. pneumoniae infections in mice exposed to a mixed radiation field or to gamma rays was more effective than single-agent therapy. In all irradiated-wounded mice, single therapy of acquired infections with an antibiotic or S-TDCM did not increase survival. Survival of irradiated-wounded mice after topical application of gentamicin sulfate cream suggested that bacteria colonizing the wound disseminated systemically in untreated irradiated mice, resulting in death from sepsis. In lethal models of acquired infections in irradiated-wounded mice, significant increases in survival were achieved when systemic treatments with S-TDCM or gentamicin were combined with topical treatments of gentamicin cream. Therapies for sepsis in all mice exposed to a mixed field were less effective than in mice exposed to gamma rays. Nonetheless, the data show a principle by which successful therapy may be provided to individuals receiving tissue trauma in conjunction with

Food irradiation

International Nuclear Information System (INIS)

Matsuyama, Akira

1990-01-01

This paper reviews researches, commentaries, and conference and public records of food irradiation, published mainly during the period 1987-1989, focusing on the current conditions of food irradiation that may pose not only scientific or technologic problems but also political issues or consumerism. Approximately 50 kinds of food, although not enough to fill economic benefit, are now permitted for food irradiation in the world. Consumerism is pointed out as the major factor that precludes the feasibility of food irradiation in the world. In the United States, irradiation is feasible only for spices. Food irradiation has already been feasible in France, Hollands, Belgium, and the Soviet Union; has under consideration in the Great Britain, and has been rejected in the West Germany. Although the feasibility of food irradiation is projected to increase gradually in the future, commercial success or failure depends on the final selection of consumers. In this respect, the role of education and public information are stressed. Meat radicidation and recent progress in the method for detecting irradiated food are referred to. (N.K.) 128 refs

Effect of gamma irradiation on nylon 6 films : swelling study

International Nuclear Information System (INIS)

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)

Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

International Nuclear Information System (INIS)

Thongphasuk, Jarunee; Thongphasuk, Piyanuch; Eamsiri, Jarurut; Pongpat, Suchada

2009-07-01

Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

Cytogenetic investigations of persons exposed to professional chronic low-dose irradiation

International Nuclear Information System (INIS)

Rangelov, V.; Mitev, L.; Petrunov, P.; Vesselinova, L.

2005-01-01

The problem of long term influence of low-doses occupational irradiation is connected with the real assessment of their consequences. The current cytogenetic investigations were done on persons working under occupational chronic external partial irradiation. Accumulated doses of external irradiation are surveyed. Data give ground for suggestion about the relationship between accumulated dose and chromosomal aberrations. The additional damage factors (diagnostic investigations, chemical substances, tobacco addict) have done the more significant influence upon aberrations appearance increasing

Heavy-ion irradiation induced diamond formation in carbonaceous materials

International Nuclear Information System (INIS)

Daulton, T. L.

1999-01-01

The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond

Experience in Cuba in the licensing during import, commissioning and operation of an Irradiator LLCo ISOGAMMA

International Nuclear Information System (INIS)

Forteza, Yamil Lopez; Reyes, Yolanda Perez; Garcia, Jose R. Quevedo; Molina, Igor I. Sarabia; Gonzalez, Leonel Omarovich; Zubiaur, Omar Cruz

2013-01-01

This work presented the experiences during the process of licensing an irradiator ISOGAMMA LLCo model according to the recommendations of the International Atomic Energy (IAEA). Aspects of the safety assessment are detailed, as well as control and verification requirements for radiation safety and security at different stages of the process (import, transportation, installation irradiator loading 60Co sources, commissioning and operation) of irradiator recently installed in Cuba. The results of the evaluation carried a source of reference and consultation necessary for the work of the regulator to consider for similar processes that lie ahead in other facilities irradiation

Effects of residual stress on irradiation hardening in stainless steels

Energy Technology Data Exchange (ETDEWEB)

Okubo, N.; Kondo, K.; Kaji, Y. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Miwa, Y. [Nuclear Energy and Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki-ken (Japan)

2007-07-01

Full text of publication follows: Structural materials in fusion reactor with water cooling system will undergo corrosion in aqueous environment and heavier irradiation than that in LWR. Irradiation assisted stress corrosion (IASCC) may be induced in stainless steels exposed in these environment for a long term of reactor operation. The IASCC is considered to be caused in a welding zone. It is difficult to predict and estimate the IASCC, because several irradiation effects (irradiation hardening, swelling, irradiation induced stress relaxation, etc) work intricately. Firstly, effects of residual stress on irradiation hardening were investigated in stainless steels. Specimens used in this study were SUS316 and SUS316L. By bending deformation, the specimens with several % plastic strain, which corresponds to weld residual stress, were prepared. Ion irradiations of 12 MeV Ni{sup 3+} were performed at 330, 400 and 550 deg. C to 45 dpa in TIARA facility at JAEA. No bent specimen was simultaneously irradiated with the bent specimen. The residual stress was estimated by X-ray residual stress measurements before and after the irradiation. The micro-hardness was measured by using nano-indenter. The irradiation hardening and the stress relaxation were changed by irradiation under bending deformation. The residual stress did not relax even for the case of the higher temperature aging at 500 deg. C for the same time of irradiation. The residual stress after ion irradiation, however, relaxed at these experimental temperatures in SUS316L. The hardness was obviously suppressed in bent SUS316L irradiated at 300 deg. C to 6 or 12 dpa. It was evident that irradiation induced stress relaxation occasionally suppressed the irradiation hardening in SUS316L. (authors)

Food irradiation

International Nuclear Information System (INIS)

Duchacek, V.

1989-01-01

The ranges of doses used for food irradiation and their effect on the processed foods are outlined. The wholesomeness of irradiated foods is discussed. The present food irradiation technology development in the world is described. A review of the irradiated foods permitted for public consumption, the purposes of food irradiaton, the doses used and a review of the commercial-scale food irradiators are tabulated. The history and the present state of food processing in Czechoslovakia are described. (author). 1 fig., 3 tabs., 13 refs

Alternative irradiation system for efficiency manganese bath determination

Energy Technology Data Exchange (ETDEWEB)

Passos Leite, Sandro, E-mail: sandro@ird.gov.b [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Wagner Pereira, Walsan, E-mail: walsan@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/no, Recreio dos Bandeirantes, CEP: 22780-160, Rio de Janeiro (Brazil); Xavier da Silva, Ademir, E-mail: ademir@con.ufrj.b [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Simoes da Fonseca, Evaldo, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/no, Recreio dos Bandeirantes, CEP: 22780-160, Rio de Janeiro (Brazil); Souza Patrao, Karla Cristina de, E-mail: karla@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/no, Recreio dos Bandeirantes, CEP: 22780-160, Rio de Janeiro (Brazil)

2010-12-15

An alternative irradiation system, which works with a radionuclide neutron source and manganese sulphate solution volume have been proposed for efficiency determination of a Manganese Bath System (MBS). This irradiation system was designed by simulation with MCNP5 code, considering a californium neutron source in several manganese sulphate volumes and different neutron reflectors. Although its solution specific activity are less than those in nuclear reactors, the simulation results have showed that the irradiation system proposed takes a manganese neutron capture increase up to 200 times when it compared to manganese neutron capture from a MBS whose diameter is about 100 cm. That becomes possible to use those samples for some of the absolute specific activity measuring methods.

Sub-micron indent induced plastic deformation in copper and irradiated steel

International Nuclear Information System (INIS)

Robertson, Ch.

1998-09-01

In this work we aim to study the indent induced plastic deformation. For this purpose, we have developed a new approach, whereby the indentation curves provides the mechanical behaviour, while the deformation mechanisms are observed thanks to Transmission Electron Microscopy (TEM). In order to better understand how an indent induced dislocation microstructure forms, numerical modeling of the indentation process at the scale of discrete dislocations has been worked out as well. Validation of this modeling has been performed through direct comparison of the computed microstructures with TEM micrographs of actual indents in pure Cu [001]. Irradiation induced modifications of mechanical behaviour of ion irradiated 316L have been investigated, thanks to the mentioned approach. An important hardening effect was reported from indentation data (about 50%), on helium irradiated 316L steel. TEM observations of the damage zone clearly show that this behaviour is associated with the presence of He bubbles. TEM observations of the indent induced plastic zone also showed that the extent of the plastic zone is strongly correlated with hardness, that is to say: harder materials gets a smaller plastic zone. These results thus clearly established that the selected procedure can reveal any irradiation induced hardening in sub-micron thick ion irradiated layers. The behaviour of krypton irradiated 316L steel is somewhat more puzzling. In one hand indeed, a strong correlation between the defect cluster size and densities on the irradiation temperature is observed in the 350 deg C -600 deg C range, thanks to TEM observations of the damage zone. On the other hand, irradiation induced hardening reported from indentation data is relatively small (about 10%) and shows no dependence upon the irradiation temperature (within the mentioned range). In addition, it has been shown that the reported hardening vanishes following appropriate post-irradiation annealing, although most of the TEM

Signal development in irradiated silicon detectors

CERN Document Server

Kramberger, Gregor; Mikuz, Marko

2001-01-01

This work provides a detailed study of signal formation in silicon detectors, with the emphasis on detectors with high concentration of irradiation induced defects in the lattice. These defects give rise to deep energy levels in the band gap. As a consequence, the current induced by charge motion in silicon detectors is signifcantly altered. Within the framework of the study a new experimental method, Charge correction method, based on transient current technique (TCT) was proposed for determination of effective electron and hole trapping times in irradiated silicon detectors. Effective carrier trapping times were determined in numerous silicon pad detectors irradiated with neutrons, pions and protons. Studied detectors were fabricated on oxygenated and non-oxygenated silicon wafers with different bulk resistivities. Measured effective carrier trapping times were found to be inversely proportional to fuence and increase with temperature. No dependence on silicon resistivity and oxygen concentration was observ...

Spectroscopic studies of irradiated glasses: Application in nuclear dosimetry

International Nuclear Information System (INIS)

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.

An ESR study on the detection of irradiated red lentil

International Nuclear Information System (INIS)

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

Food irradiation dosimetry using thermoluminescence of quartz sand

International Nuclear Information System (INIS)

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

1993-01-01

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

Whole-body irradiation technique: physical aspects

International Nuclear Information System (INIS)

Venencia, D.; Bustos, S.; Zunino, S.

1998-01-01

The objective of this work has been to implement a Total body irradiation technique that fulfill the following conditions: simplicity, repeatability, fast and comfortable positioning for the patient, homogeneity of the dose between 10-15 %, short times of treatments and In vivo dosimetric verifications. (Author)

Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

Energy Technology Data Exchange (ETDEWEB)

Franco, Manuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2014-08-01

The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential

Immune response against antigens irradiated with 60Co gamma-rays

International Nuclear Information System (INIS)

Baptista, J.A.; Spencer, P.J.; Oliveira, J.E.; Casare, M.S.; Nascimento, N.

2006-01-01

In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase from Bothrops jararacussu, and of ovalbumin before and after irradiation with 60 Co γ-rays. Isogenic mice were immunized with either native or irradiated proteins. The circulating antibodies were isotyped and titrated by ELISA. Results indicate that irradiated proteins were immunogenic and the antibodies elicited by them were able to recognize the native proteins in ELISA. Data also indicate that the irradiated protein induced higher titers of IgG2a and IgG2b, suggesting that Th1 cells were predominantly involved in the immune response. Structural modifications of the proteins were investigated by SDSPAGE, mass spectrometry and size exclusion chromatography. According to our data, irradiation promoted structural modifications on both proteins, characterized by higher molecular weight forms (aggregates and oligomers). When analyzed by mass spectrometry, the irradiated bothropstoxin appeared in several oxidized forms. These results indicate that irradiation of toxic proteins can promote significant modifications in their structures, but still retain many of the original antigenic and immunological properties of native form. (author)

Industrial Irradiation of Polymers: Systems and Concepts

International Nuclear Information System (INIS)

Mittendorfer, J.

2006-01-01

This paper provides a systematic survey of systems and concepts used in the industrial irradiation of polymers. It consists basically of three parts: in the first part, different types of applications like wires and cables, pipes and engineering plastics are discussed and the associated irradiation systems analyzed and highlighted according their basics modules. These are identified as the radiation source, the product handling system, process control and facility/shielding layout. In the second part, the irradiation process design is reviewed in detail. The discussion starts with the requirement analysis, e.g. the desired polymer parameters and effects, continues with a process development roadmap and concludes with process verification and validation. Special attention is drawn to process control, which plays an important role in industrial irradiation technology. The use of mathematical modeling to facilitate and support process and system design is discussed as well and several examples are given which demonstrate their capabilities. In the third part, the design of a electron beam facility for the irradiation of small plastic parts for the automotive industry is worked out in detail. Besides system and product handling considerations, throughput and economical estimates are provided. The paper concludes with a summary of the design and concept bullets which proved to be important in history and can facilitate new developments which will enhance the potential of industrial polymer irradiation

Tracking with heavily irradiated silicon detectors operated at cryogenic temperatures

International Nuclear Information System (INIS)

Casagrande, L.; Barnett, B.M.; Bartalina, P.

1999-01-01

In this work, the authors show that a heavily irradiated double-sided silicon microstrip detector recovers its performance when operated at cryogenic temperatures. A DELPHI microstrip detector, irradiated to a fluence of ∼4 x 10 14 p/cm 2 , no longer operational at room temperature, cannot be distinguished from a non-irradiated one when operated at T < 120 K. Besides confirming the previously observed Lazarus effect in single diodes, these results establish, for the first time, the possibility of using standard silicon detectors for tracking applications in extremely demanding radiation environments

Fortified foods, new opportunity for irradiation application

International Nuclear Information System (INIS)

Taipina, Magda S.; Sabato, Susy F.; Mastro, Nelida L. del

2000-01-01

One of the most important steps, in order to improve the quality of foodstuffs, in the last forty years is represented by fortified foods. The fortification foods means complementary addition of nutrients to content of foodstuffs. The macro-nutrients (carbohydrates, proteins and lipids) are relativity steady when submitted to irradiation. The micro-nutrients, speciality the vitamins, can be sensible to any method. This work has analysed fortified foods with Fe, Ca, Mg, Zn, vitamin A, riboflavine, vitamin C and folic acid , as well as, the perspective of adjusting the food irradiation process with fortification foods

Technological characteristics of bread containing integral irradiated flours

International Nuclear Information System (INIS)

Teixeira, Christian A.H.M.; Mastro, Nelida L. del

2011-01-01

Wheat is normally used to make bread, pasta, and noodles, because among the cereal flours, only wheat flour has the ability to form cohesive dough upon hydration. For that reason, only partial substitution of wheat flour can be recommended. In this work, pan breads were prepared with 30% content of irradiated whole wheat, whole rye and coarse cornmeal and the influence of blending on bread making capabilities investigated through some technological characteristics. All-brand wheat, rye and cornmeal flours were irradiated with 0, 1, 3 and 9 kGy in a 60 Co and the deformation force, height and weight of breads prepared with those blends were then determined. Breads prepared with irradiated whole wheat flour showed an increase in the deformation force with the increase of radiation dose. The bread height presented also an increase for the doses of 1 and 3 kGy. Breads prepared with refined wheat flour blended with irradiated whole rye flour showed an increased deformation force for radiation doses of 1 and 3 kGy and an increase in weight for samples irradiated with 1 kGy. Coarse cornmeal blended flour showed a great increase of the deformation force upon irradiation, and an increase in weight for samples irradiated with 3 kGy. The results indicate that the addition of irradiated integral flour, whole wheat, whole rye flour and cornmeal to wheat flour may confer changes in physical properties beside an increment in nutritional value. (author)

Functional modifications of macrophage activity after sublethal irradiation

International Nuclear Information System (INIS)

Swartz, R.P.

1982-01-01

The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin

Marketing and economic analysis of mango irradiation processing in egypt

International Nuclear Information System (INIS)

Elkhateeb, M.A.

2004-01-01

The aim of this work is to examine the marketing and economic feasibility of a project for mango irradiation in Egypt. The Egyptian market was analyzed considering the production size and cultivated area distributed over several years,the percentage of the total loss of mango that can be avoided by irradiation, the market tests in Egypt and other countries was presented and the normal distribution channels of mango when using radiation technology. The financial and economic analysis of the establishment of pallet carrier unite for the irradiation of mango was also carried out. The following investment criteria were utilized for the commercial evaluation: benefit-cost ratio, pay back period, average rate of return and net present value. The results of this analysis showed that the installation of a unit for the irradiation of mango in Egypt would be economically viable. The unit cost of irradiation would decline if the irradiator is be used as a multipurpose facility

Irradiated foods

International Nuclear Information System (INIS)

Darrington, Hugh

1988-06-01

This special edition of 'Food Manufacture' presents papers on the following aspects of the use of irradiation in the food industry:- 1) an outline view of current technology and its potential. 2) Safety and wholesomeness of irradiated and non-irradiated foods. 3) A review of the known effects of irradiation on packaging. 4) The problems of regulating the use of irradiation and consumer protection against abuse. 5) The detection problem - current procedures. 6) Description of the Gammaster BV plant in Holland. 7) World outline review. 8) Current and future commercial activities in Europe. (U.K.)

Pre-and post-gamma irradiation fetal bovine serum genotoxic evaluation

International Nuclear Information System (INIS)

Pilili, J.P.; Molinari, G.; Gonzalez, N.V.; Soloneski, S.; Reigosa, M.L.; Larramendy, M.L.

2008-01-01

Fetal bovine serum (FBS) is an essential component to propagate cells in vitro. Different methods are used by the industry to eliminate xenobiotic agents before their use, among them the ionizing radiations application. The aim of the present work was to analyze the existence of xenobiotic agents in 18 FBS lots manufactured by Internegocios S.A., Mercedes, Pcia. Bs. As., assessed pre- and postirradiation. The analysis of the frequency of sister chromatid exchanges (SCEs) and micronuclei (MNs) in CHO K1 cells were used as genotoxicity endpoints. The results showed SCEs increase in 44% of the lots (71% of non-irradiated sera and 29% of irradiated sera) and in MNs only in a sample non-irradiated (6.25%). These results would render evident the presence of agents with genotoxic capacity as much in lots of FBS irradiated as in non-irradiated. Thus, the irradiation not only grants sterility to FBS but eliminates or inhibits those xenobiotics with deleterious capacity present in them before irradiation. Finally, variations in the conditions during irradiation (temperature, time of exposure) could generate compound with clastogenic and/or aneugenic capacity that could affect the correct propagation of cells in culture. (authors)

Effects of CTR irradiation on the mechanical properties of structural materials

International Nuclear Information System (INIS)

Wiffen, F.W.

1976-11-01

Mechanical properties of CTR structural materials are important in determining the reliability and economics of fusion power. Furthermore, these properties are significantly affected by the high neutron flux experienced by components in the regions near the plasma of the fusion reactor. In general, irradiation hardens the material and leads to a reduction in ductility. An exception to this is in some complex engineering alloys where either hardening or softening can be observed depending on the alloy and the irradiation conditions. Regardless of this restriction, irradiation usually leads to a reduction in ductility. Available tensile data examined in this paper show that significant ductility reduction can be found for irradiation conditions typical of CTR operation. Consideration of these effects show that extensive work will be needed to fully establish the in-service properties of CTR structures. This information will be used by designers to develop conditions and design philosophies adapted to avoid the most deleterious conditions and minimize stresses on structures on reactor design. The information will also be used as input to alloy development programs with goals of producing materials more resistant to property degradation during irradiation. It is clear that a great deal of additional work will be required both to understand the effect of CTR irradiation on properties and to develop optimal alloys for this application

Study of the stability of the tragacanto rubber irradiated

International Nuclear Information System (INIS)

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

Tensile properties of vanadium alloys irradiated at 390{degrees}C in EBR-II

Energy Technology Data Exchange (ETDEWEB)

Chung, H.M.; Tsai, H.C.; Nowicki, L.J. [Argonne National Lab., IL (United States)] [and others

1997-08-01

Vanadium alloys were irradiated in Li-bonded stainless steel capsules to {approx}390{degrees}C in the EBR-II X-530 experiment. This report presents results of postirradiation tests of tensile properties of two large-scale (100 and 500 kg) heats of V-4Cr-Ti and laboratory (15-30 kg) heats of boron-doped V-4Cr-4Ti, V-8Cr-6Ti, V-5Ti, and V-3Ti-1Si alloys. Tensile specimens, divided into two groups, were irradiated in two different capsules under nominally similar conditions. The 500-kg heat (No. 832665) and the 100-kg heat (VX-8) of V-4Cr-4Ti irradiated in one of the subcapsules exhibited complete loss of work-hardening capability, which was manifested by very low uniform plastic strain. In contrast, the 100-kg heat of V-4Cr-4Ti irradiated in another subcapsule exhibited good tensile properties (uniform plastic strain 2.8-4.0%). A laboratory heat of V-3Ti-1Si irradiated in the latter subcapsule also exhibited good tensile properties. These results indicate that work-hardening capability at low irradiation temperatures varies significantly from heat to heat and is influenced by nominally small differences in irradiation conditions.

Dose determination in irradiated chicken meat by ESR method

International Nuclear Information System (INIS)

Polat, M.

1996-01-01

In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

Irradiation-accelerated corrosion of reactor core materials

International Nuclear Information System (INIS)

Bartels, David; Was, Gary; Jiao, Zhijie

2012-09-01

The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, but also applies to most all other GenIV concepts. Of these four drivers, the combination of radiation and corrosion presents a unique and extremely challenging environment for materials, for which an understanding of the fundamental science is essentially absent. Irradiation can affect corrosion or oxidation in at least three different ways. Radiation interaction with water results in the decomposition of water into radicals and oxidizing species that will increase the electrochemical corrosion potential and lead to greater corrosion rates. Irradiation of the solid surface can produce excited states that can alter corrosion, such as in the case of photo-induced corrosion. Lastly, displacement damage in the solid will result in a high flux of defects to the solid-solution interface that can alter and perhaps, accelerate interface reactions. While there exists reasonable understanding of how corrosion is affected by irradiation of the aqueous environment, there is little understanding of how irradiation affects corrosion through its impact on the solid, whether metal or oxide. The reason is largely due to the difficulty of conducting experiments that can measure this effect separately. We have undertaken a project specifically to separate the several effects of irradiation on the mechanisms of corrosion. We seek to answer the question: How does radiation damage to the solution-oxide couple affect the oxidation process differently from radiation damage to either component alone? The approach taken in this work is to closely compare corrosion accelerated by (1) proton irradiation, (2) electron irradiation, and (3) chemical corrosion potential effects alone, under typical PWR operating conditions at 300 deg. C. Both 316 stainless steel and zirconium are to be studied. The proton

The criteria and the design of MINT's latex irradiator

International Nuclear Information System (INIS)

Razali Hamzah; Muhd Khairi Muhd Said; Muhd Ariff Hamzah; Wan Manshol Wan Zin; Wan Abd Hadi Wan Abu Bakar; Muhd Noor Muhd Yunus

1996-01-01

The demand for RVNRL is continually on the upsurge and the present irradiation technique at the present SINAGAMA plant is not sufficient and practical to meet the demand. A number of conceptual designs were evolved to design according to the requirements of cost-effective and highly efficient plant. The number of options are described. In 1994 MINT work with NUKEM to build an automatic continuous latex irradiation plant

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

Energy Technology Data Exchange (ETDEWEB)

Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel; Hattar, Khalid

2017-09-29

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

Directory of Open Access Journals (Sweden)

Caitlin Anne Taylor

2017-09-01

Full Text Available Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM. This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs: zirconium alloys and LiAlO2.

Gamma irradiation for sewage treatment at US army facilities

International Nuclear Information System (INIS)

Van den Berg, A.J.; Hollis, H.D.; Musselman, H.D.; Woodbridge, D.D.

1975-01-01

The US Army Corps of Engineers has been sponsoring research for many years on the use of gamma irradiation for disinfection and sterilization of sewage plant effluents. Initial research was directed to laboratory experiments using sterile solutions to determine the effects of gamma irradiation on E. coli, M-pyogenes and M-smegmatis organisms, and on the chemical constituents of sewage such as phenols, surfactants and pesticides. The results of the initial research warranted further study using municipal sewage secondary effluent as test samples. Current research is directed towards investigating the effects of radiation on the constituents of sewage sludge and on the cyst stage of the amoebic protozoa. Consideration has been given by the Corps to the management of waste-waters by disposal on land. Legal and medical reasons dictate that the plant effluents be sterilized before being used as fertilizers and soil conditioners. Gamma radiation from isotopic sources appears to be the best source of sterilizing energy for Army waste-water disposal. The Corps of Engineers is considering the construction of an experimental gamma irradiation pilot facility to validate laboratory experimental work and to establish design criteria for operating plants. The data obtained will provide a basis for performing detailed cost effectiveness studies on gamma irradiation as a method to treat secondary plant effluent. In addition, optimization work will be conducted to determine where in the sewage treatment cycle the use of gamma irradiation will produce the best results in meeting current and anticipated standards. (author)

Medical irradiation of children. Beware of too fast conclusion; Irradiation medicale de l'enfant. Attention aux conclusions hatives

Energy Technology Data Exchange (ETDEWEB)

Brisse, H. [Institut Curie, Dept. d' Imagerie, 75 - Paris (France); Sirinelli, D. [Hopital Clocheville, Service de Radiologie et Echographie, 37 - Tours (France); Adamsbaum, C. [Hopital Saint-Vincent-de-Paul, Service de Radiologie, 75 - Paris (France); Chateil, J.F. [Hopital Pellegrin, Unite de Radiopediatrie, 33 - Bordeaux (France); Claudon, M. [Centre Hospitalier Universitaire Nancy-Hopital Brabois Enfants, Service de Radiologie, 54 - Vandoeuvre-les-Nancy (France); Geoffray, A. [Fondation Lenval, Service de Radiologie, 06 - Nice (France); Petit, P. [Hopital de la Timone, Service de Radiologie, 13 - Marseille (France); Rausin, L. [Centre Hospitalier Regional de la Citadelle, Service de Radiologie, Liege (Belgium); Panuel, M. [Hopital Nord, Service de Radiologie, 13 - Marseille (France)

2004-10-01

The publication in january 2004 in the British medical journal of the article of P. Hall and coll. 'Effect of low doses of ionizing irradiation in infancy on cognitive function in adulthood: Swedish population based cohort study, has been noticed by the Radiation protection group of the French speaking society of pediatrics imaging. The authors evaluate the psycho-motor development of less eighteen months years old children and irradiated between 1930 and 1959 for a face angioma. They study for each dose of irradiation ( from 0 to 250 m Gy) the level of school attendance and their results to the psycho-motor tests made during conscription medical examination. They noticed a diminution of 50% of the access success rate to university for the children having received an irradiation dose of 250 mG. No effect is noticed under the irradiation dose of 100 mGy. In their conclusions the authors compare these irradiation doses to these ones delivered in brain scanner examination. These results seem overestimated compared with the work made on fetuses ( publication 84 of ICRP) then the fetus is considered as more sensitive to ionizing radiations than the infant. The dose of 120 mGy is found in the literature and now the dose delivered in pediatrics are in the area of 0 and 100 mGy where no effect has been revealed in the cohort of irradiated children. The article does not include the principle of justification that is used nowadays and the replacement by the trans fontanel echography has allowed to reduce the number of brain scanner, used only for limited cases where the benefit is superior the the risk of irradiation. (N.C.)

Tensile properties of helium-injected V-15Cr-5Ti after irradiation in EBR-II

International Nuclear Information System (INIS)

Grossbeck, M.L.; Horak, J.A.

1985-01-01

Miniature specimens of V-15Cr-5Ti were prepared in the annealed condition and with 10, 20, and 30% cold work. The annealed specimens were cyclotron injected with helium and irradiated in sodium in EBR-II. The cold-worked specimens were irradiated in EBR-II but not helium injected. The specimens were irradiated at 400, 525, 625, and 700 0 C and received a fluence of 4.1 to 5.5 x 10 26 neutrons/m 2 (E > 0.1 meV). Tensile testing revealed very significant embrittlement as a result of the neutron irradiation but a much smaller change, mostly at 400 0 C, resulting from helium injection. 5 references, 9 figures, 2 tables

Polymerization of sodium methacrylate induced by irradiation

International Nuclear Information System (INIS)

Galvan S, A.

1998-01-01

This work has two objectives, first: it is pretended to localize the lines of carbon links in its IR spectra, and second: following the polymerization of sodium methacrylate according to that it is irradiated with gamma rays. (Author)

SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

Energy Technology Data Exchange (ETDEWEB)

Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent; Biondo, Stephane; Vervisch, Vanessa [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231,13397 Marseille Cedex 20, (France); Szalkai, Dora; Klix, Axel [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344, (Germany); Vermeeren, Ludo [SCK-CEN, Boeretang 200, B-2400 Mol, (Belgium); Saenger, Richard [Schlumberger, Clamart, (France); Lyoussi, Abadallah [CEA, DEN, Departement d' Etudes des Reacteurs, Service de Physique Experimentale, Laboratoire Dosimetrie Capteurs Instrumentation, 13108 Saint-Paul-lez-Durance, (France)

2015-07-01

In the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Work is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)

Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion of human bone marrow mesenchymal stem cells.

Directory of Open Access Journals (Sweden)

Sabrina Viau

Full Text Available We recently developed and characterized a standardized and clinical grade human Platelet Lysate (hPL that constitutes an advantageous substitute for fetal bovine serum (FBS for human mesenchymal stem cell (hMSC expansion required in cell therapy procedures, avoiding xenogenic risks (virological and immunological and ethical issues. Because of the progressive use of pathogen-reduced (PR labile blood components, and the requirement of ensuring the viral safety of raw materials for cell therapy products, we evaluated the impact of the novel procedure known as THERAFLEX UV-Platelets for pathogen reduction on hPL quality (growth factors content and efficacy (as a medium supplement for hMSC expansion. This technology is based on short-wave ultraviolet light (UV-C that induces non-reversible damages in DNA and RNA of pathogens while preserving protein structures and functions, and has the main advantage of not needing the addition of any photosensitizing additives (that might secondarily interfere with hMSCs.We applied the THERAFLEX UV-Platelets procedure on fresh platelet concentrates (PCs suspended in platelet additive solution and prepared hPL from these treated PCs. We compared the quality and efficacy of PR-hPL with the corresponding non-PR ones. We found no impact on the content of five cytokines tested (EGF, bFGF, PDGF-AB, VEGF and IGF-1 but a significant decrease in TGF-ß1 (-21%, n = 11, p<0.01. We performed large-scale culture of hMSCs from bone marrow (BM during three passages and showed that hPL or PR-hPL at 8% triggered comparable BM-hMSC proliferation as FBS at 10% plus bFGF. Moreover, after proliferation of hMSCs in an hPL- or PR-hPL-containing medium, their profile of membrane marker expression, their clonogenic potential and immunosuppressive properties were maintained, in comparison with BM-hMSCs cultured under FBS conditions. The potential to differentiate towards the adipogenic and osteogenic lineages of hMSCs cultured in parallel

Pathogen reduction through additive-free short-wave UV light irradiation retains the optimal efficacy of human platelet lysate for the expansion of human bone marrow mesenchymal stem cells.

Science.gov (United States)

Viau, Sabrina; Chabrand, Lucie; Eap, Sandy; Lorant, Judith; Rouger, Karl; Goudaliez, Francis; Sumian, Chryslain; Delorme, Bruno

2017-01-01

We recently developed and characterized a standardized and clinical grade human Platelet Lysate (hPL) that constitutes an advantageous substitute for fetal bovine serum (FBS) for human mesenchymal stem cell (hMSC) expansion required in cell therapy procedures, avoiding xenogenic risks (virological and immunological) and ethical issues. Because of the progressive use of pathogen-reduced (PR) labile blood components, and the requirement of ensuring the viral safety of raw materials for cell therapy products, we evaluated the impact of the novel procedure known as THERAFLEX UV-Platelets for pathogen reduction on hPL quality (growth factors content) and efficacy (as a medium supplement for hMSC expansion). This technology is based on short-wave ultraviolet light (UV-C) that induces non-reversible damages in DNA and RNA of pathogens while preserving protein structures and functions, and has the main advantage of not needing the addition of any photosensitizing additives (that might secondarily interfere with hMSCs). We applied the THERAFLEX UV-Platelets procedure on fresh platelet concentrates (PCs) suspended in platelet additive solution and prepared hPL from these treated PCs. We compared the quality and efficacy of PR-hPL with the corresponding non-PR ones. We found no impact on the content of five cytokines tested (EGF, bFGF, PDGF-AB, VEGF and IGF-1) but a significant decrease in TGF-ß1 (-21%, n = 11, p<0.01). We performed large-scale culture of hMSCs from bone marrow (BM) during three passages and showed that hPL or PR-hPL at 8% triggered comparable BM-hMSC proliferation as FBS at 10% plus bFGF. Moreover, after proliferation of hMSCs in an hPL- or PR-hPL-containing medium, their profile of membrane marker expression, their clonogenic potential and immunosuppressive properties were maintained, in comparison with BM-hMSCs cultured under FBS conditions. The potential to differentiate towards the adipogenic and osteogenic lineages of hMSCs cultured in parallel in the

Role of internal stresses in the transient of irradiation growth of zircaloy-2

International Nuclear Information System (INIS)

Tome, C.N.; Christodoulou, N.; Turner, P.A.; Miller, M.A.; Woo, C.H.; Root, J.; Holden, T.M.

1995-07-01

A 'self-consistent' polycrystalline model is used to simulate irradiation growth of Zircaloy-2 samples irradiated at about 330 K. The predictions of the model are compared with experimental measurements obtained from specimens irradiated in the Advanced Test Reactor (ATR) at Idaho Falls. Three types of material are studied here: annealed, cold worked in tension and cold worked by rolling. In general, the growth rate attains a steady-state value after it goes through a transient that depends on the initial state of the material. The transient growth behaviour is explained in terms of the evolution of intergranular residual stresses that are present in the sample, and in terms of the dislocation structure. From this study, information regarding irradiation creep and growth mechanisms occurring at the single crystal level is obtained. (author). 28 refs., 1 tab., 4 figs

MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

Energy Technology Data Exchange (ETDEWEB)

Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

Evaluation of Shortwave Infrared Atmospheric Correction for Ocean Color Remote Sensing of Chesapeake Bay

Science.gov (United States)

Werdell, P. Jeremy; Franz, Bryan A.; Bailey, Sean W.

2010-01-01

The NASA Moderate Resolution Imaging Spectroradiometer onboard the Aqua platform (MODIS-Aqua) provides a viable data stream for operational water quality monitoring of Chesapeake Bay. Marine geophysical products from MODIS-Aqua depend on the efficacy of the atmospheric correction process, which can be problematic in coastal environments. The operational atmospheric correction algorithm for MODIS-Aqua requires an assumption of negligible near-infrared water-leaving radiance, nL(sub w)(NIR). This assumption progressively degrades with increasing turbidity and, as such, methods exist to account for non-negligible nL(sub w)(NIR) within the atmospheric correction process or to use alternate radiometric bands where the assumption is satisfied, such as those positioned within shortwave infrared (SWIR) region of the spectrum. We evaluated a decade-long time-series of nL(sub w)(lambda) from MODIS-Aqua in Chesapeake Bay derived using NIR and SWIR bands for atmospheric correction. Low signal-to-noise ratios (SNR) for the SWIR bands of MODIS-Aqua added noise errors to the derived radiances, which produced broad, flat frequency distributions of nL(sub w)(lambda) relative to those produced using the NIR bands. The SWIR approach produced an increased number of negative nL(sub w)(lambda) and decreased sample size relative to the NIR approach. Revised vicarious calibration and regional tuning of the scheme to switch between the NIR and SWIR approaches may improve retrievals in Chesapeake Bay, however, poor SNR values for the MODIS-Aqua SWIR bands remain the primary deficiency of the SWIR-based atmospheric correction approach.

Advanced shortwave infrared and Raman hyperspectral sensors for homeland security and law enforcement operations

Science.gov (United States)

Klueva, Oksana; Nelson, Matthew P.; Gardner, Charles W.; Gomer, Nathaniel R.

2015-05-01

Proliferation of chemical and explosive threats as well as illicit drugs continues to be an escalating danger to civilian and military personnel. Conventional means of detecting and identifying hazardous materials often require the use of reagents and/or physical sampling, which is a time-consuming, costly and often dangerous process. Stand-off detection allows the operator to detect threat residues from a safer distance minimizing danger to people and equipment. Current fielded technologies for standoff detection of chemical and explosive threats are challenged by low area search rates, poor targeting efficiency, lack of sensitivity and specificity or use of costly and potentially unsafe equipment such as lasers. A demand exists for stand-off systems that are fast, safe, reliable and user-friendly. To address this need, ChemImage Sensor Systems™ (CISS) has developed reagent-less, non-contact, non-destructive sensors for the real-time detection of hazardous materials based on widefield shortwave infrared (SWIR) and Raman hyperspectral imaging (HSI). Hyperspectral imaging enables automated target detection displayed in the form of image making result analysis intuitive and user-friendly. Application of the CISS' SWIR-HSI and Raman sensing technologies to Homeland Security and Law Enforcement for standoff detection of homemade explosives and illicit drugs and their precursors in vehicle and personnel checkpoints is discussed. Sensing technologies include a portable, robot-mounted and standalone variants of the technology. Test data is shown that supports the use of SWIR and Raman HSI for explosive and drug screening at checkpoints as well as screening for explosives and drugs at suspected clandestine manufacturing facilities.

Seed germination of peanuts irradiated with cobalt (60CO)

International Nuclear Information System (INIS)

Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B.; Leal, Artur S. Cavalcanti

2010-01-01

This work was realized to evaluate the effect of gamma irradiation ( 60 Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

Irradiation detection of food by DNA Comet Assay

International Nuclear Information System (INIS)

Khan, A.A.; Delincee, H.

1999-01-01

Microgel electrophoresis of single cells or nuclei (DNA Comet Assay) has been investigated to detect irradiation treatment of more than 50 food commodities e.g. meats, seafood, cereals, pulses, nuts, fruits and vegetables, and spices. The foodstuffs have been exposed to radiation doses covering the range of potential commercial irradiation for inactivation of pathogenic and spoilage micro-organisms, for insect disinfestation and for shelf-life extension. The Comet Assay is based on detection of DNA fragments presumptive to irradiation. For most of the food items investigated, the assay can be applied successfully for irradiation detection by working out different conditions of the assay. However, with some of the foods difficulties arose due to - lack of discrimination between the irradiated and unirradiated food samples due to the presence of the same kinds of comets in both cases and the total absence of the typical intact cells in unirradiated samples. - Sufficient DNA material was not available from some of the foods. - Insufficient lysis of the cell walls in case of some plant foods. In conclusion, the DNA Comet Assay can help to detect the irradiation treatment of several varieties of foods using low-cost equipment in a short time of analysis. (orig.)

Storage tests with irradiated and non-irradiated onions