Simulation of gamma irradiation system for a ballast water treatment

International Nuclear Information System (INIS)

Faez, T. P.; Sarkar, S.

2006-01-01

Invasion by different kinds of ballast the water microorganisms is one of the most important marine environment problems around the world therefore preventing the invasion of these unwanted and harmful stowaways is one of the main strategies of responsible agencies. Some of these methods such as ocean exchange, heating, filtration, hydro cyclones, UV irradiation and chemical treatment, have various problems such as technical deficiency, high costs, lack of safety and environmental side effects. Materials and Methods: A novel system of treatment by Gamma irradiation is designed to irradiate the blast water uniformly and effectively. To determine the dose distribution as a function of distance from the irradiation source, the MCNP code was used. The systems used for source implant in this simulation were Paterson-Parker, Paris and Network systems. In each system, Sivert-integral and inverse square law were used in MATLAB program to determine the dose distribution. Results: Results of initial laboratory tests on offshore water samples of Siri Island indicated that the appropriate dose for deactivation of organisms of water samples is approximately one kGy. It has been demonstrated that the dose can be provided by twenty five 100,000 Ci line sources of ' 60 Co in a triangle implant arranged in a 1*1*1 m3 cubic shape water pipe. In order to increase efficiency and radiation safety, water passed from two other coaxial and bigger cubes, after passing from the first cube. A one meter thick wall of concrete around the cubes was adequate to shield the system completely. Conclusion: The main advantages of this system such as high efficiency, safety, reliability, minimum environmental adverse effects, proves that this novel method not only can be used for ballast water treatment, but is also effective for drinking water purification

Zircaloy behaviour in high temperature irradiated water

International Nuclear Information System (INIS)

Urbanic, V.F.

1982-04-01

The corrosion and hydriding of Zircaloy during irradiation in high temperature water is strongly dependent on the oxygen concentration of the water. Corrosion tests in the NRX and NRU research reactors using small samples have demonstrated the importance of water chemistry in maintaining Zircaloy corrosion and hydriding within acceptable limits. Zircaloy fuel cladding develops non-uniform, patch-type oxides during irradiation in hich temperature water containing dissolved oxygen. Results from examinations of prototype fuel cladding irradiated in the research reactors are presented to show how local variations in coolant flow, fast neutron flux, metallurgical structure and surface condition can influence the onset of non-uniform corrosion under these conditions. Destructive examinations of CANDU-PHW reactor fuel cladding have emphasized the importance of good chemistry control, especially the dissolved oxygen concentration of the water. When reactor coolants are maintained under normal reducing conditions at high pH (5 to 10 cm 3 D 2 /kg D 2 O; 2 /kg D 2 O; pH > 10 with LiOD), Zircaloy cladding develops non-uniform, patch-type oxides. These patch-type oxides tend to coalesce with time to form a thick, uniform oxide layer after extended exposure. Under reducing coolant conditions, Zircaloy cladding absorbs less than 200 mg D/kg Zr (approximately 2.5 mg/dm 2 equivalent hydrogen) in about 500 days. With oxygen in the coolant, deuterium absorption is considerably less despite the significant increase in corrosion under such conditions

Photogeneration of reactive transient species upon irradiation of natural water samples: Formation quantum yields in different spectral intervals, and implications for the photochemistry of surface waters.

Science.gov (United States)

Marchisio, Andrea; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

2015-04-15

Chromophoric dissolved organic matter (CDOM) in surface waters is a photochemical source of several transient species such as CDOM triplet states ((3)CDOM*), singlet oxygen ((1)O2) and the hydroxyl radical (OH). By irradiation of lake water samples, it is shown here that the quantum yields for the formation of these transients by CDOM vary depending on the irradiation wavelength range, in the order UVB > UVA > blue. A possible explanation is that radiation at longer wavelengths is preferentially absorbed by the larger CDOM fractions, which show lesser photoactivity compared to smaller CDOM moieties. The quantum yield variations in different spectral ranges were definitely more marked for (3)CDOM* and OH compared to (1)O2. The decrease of the quantum yields with increasing wavelength has important implications for the photochemistry of surface waters, because long-wavelength radiation penetrates deeper in water columns compared to short-wavelength radiation. The average steady-state concentrations of the transients ((3)CDOM*, (1)O2 and OH) were modelled in water columns of different depths, based on the experimentally determined wavelength trends of the formation quantum yields. Important differences were found between such modelling results and those obtained in a wavelength-independent quantum yield scenario. Copyright © 2015 Elsevier Ltd. All rights reserved.

Irradiation techniques for the release of bound heavy metals in natural waters and blood

International Nuclear Information System (INIS)

Batley, G.E.; Farrar, Y.J.

1978-01-01

Irradiation techniques are compared with conventional acid digestion procedures for the release of bound heavy metals in natural waters and in blood, before their determination by anodic stripping voltammetry. Ultra-violet irradiation of acidified water with a 550-W mercury vapour lamp releases bound zinc, cadmium, lead and copper after 4 h. The same results can be achieved with a 30 Mrad dose of high-energy γ-irradiation. These techniques are also effective for the release of metals in whole blood and blood plasma, where sample volumes as small as 200 μl are adequate in analyses for zinc, copper and lead. By comparison with acid digestion and solvent extraction methods, irradiation treatments offer the advantages of minimum sample manipulation and negligible reagent blanks. (Auth.)

Improved Extraction and Quality Characterization of Water-Soluble Polysaccharide from Gamma-Irradiated Lentinus edodes.

Science.gov (United States)

Akram, Kashif; Shahbaz, Hafiz Muhammad; Kim, Gui-Ran; Farooq, Umar; Kwon, Joong-Ho

2017-02-01

Gamma irradiation was applied to the improved extraction of water-soluble polysaccharides (WSPs) from dried Lentinus edodes. Irradiation provided a dose-dependent increase in extraction yield (0 kGy, 2.01%; 7.5 kGy, 4.03%; 15 kGy, 7.17%) and purity (0 kGy, 78.8%; 7.5 kGy, 83.1%; 15 kGy, 85.6%) of the WSPs from hot-water extraction. The effect of irradiation was evident in the degraded microstructures and reduced molecular weights of the WSPs. However, nuclear magnetic resonance, Fourier-transform infrared, and X-ray diffraction spectroscopic analyses provided comparable structures of WSPs from nonirradiated and irradiated samples. UV-visible spectra showed a dose-dependent decline in intensity, but an improvement in thermal properties of the WSPs from the irradiated mushroom samples was observed. © 2017 Institute of Food Technologists®.

Effect of Gamma and Electron Beam Irradiation on Textile Waste Water

International Nuclear Information System (INIS)

Selambakkannu, S.; Khomsaton Abu Bakar; Ting, T.M.

2011-01-01

In this studies gamma and electron beam irradiation was used to treat textile waste water. Comparisons between both types of irradiation in terms of effectiveness to degrade the pollutants present in textile waste water was done. Prior to irradiation, the raw wastewater was diluted using distilled water to a target concentration of COD 400 mg/l. The sample was irradiated at selected doses between the ranges of 10 kGy to 100 kGy. The results showed that irradiation has significantly contributed in the reduction of the highly colored refractory organic pollutants. The COD removal at the lowest dose, 10 kGy, was reduced to 390 mg/l for gamma and 400 mg/l for electron beam. Meanwhile, at the highest dose, 100 kGy, the COD was reduced to 125 mg/l for gamma and 144 mg/l for electron beam. The degree of removal is influenced by the dose introduced during the treatment process. As the dose increased, the higher the removal of organic pollutant was recorded. However, gamma irradiation is more effective although the differences are not significant between gamma and electron beam irradiation. On the other hand, other properties of the wastewater such as pH, turbidity, suspended solid, BOD and color also shows a gradual decrease as the dose increases for both types of irradiation. (author)

Modelling of Disinfection by-products formation via UV irradiation of the water from Tajan River (source water for Sari drinking water, Iran

Directory of Open Access Journals (Sweden)

Allahbakhsh Javid

2013-11-01

Full Text Available Background & Aims of the Study Irradiation with ultraviolet light (UV is used for the disinfection of bacterial contaminants in the production of potable water. The main objective of the study was to investigate and model Disinfection By-Products (DBPs formation due to the UV Irradiation of the Tajan River water under different Irradiation conditions. Materials & Methods:  Water samples were collected throughout September 2011 to August 2013. Transportation of the sample to the laboratory was done on ice in a cooler, and physiochemical analysis was conducted immediately within one day. Dissolved organic carbon (DOC was determined by a TOC analyzer. Irradiation experiments were conducted in a series of 25 mL glass serum bottles with Teflon septa. The present study adopts an orthogonal design. The design involved irradiation with UV at a UV/DOC ratio of 0.5–3.0 and incubating (headspace-free storage for 5–25 sec. A 1 mM phosphate buffer maintained the pH at 6, 7, or 8 respectively, and an incubator maintained the temperature (Temp at 15, 20, or 25 °C respectively. The development of empirical models for DBPs formation used a multivariate regression procedure (stepwise which applied the SPSS System for Windows (Version 16.0. Results:  The results showed that the total DBPs formation ranged between 12.3 and 67.4 mg/l and that control of the levels was primarily due to the reaction time and the dissolved organic carbon level (DOC in the water. Conclusions:  Reaction time and level of DOC concentrations in water exerted a dominant influence on the formation of DBPs during the UV irradiation of water from the Tajan River. The relationships between the measured and predicted values were satisfactory with R 2 values ranging from 0.89 (for Octanal–0.92 (for Formaldehydes. The DOC level in water is the key factor in controlling DBPs formation.

Multielement neutron activation analysis of underground water samples

International Nuclear Information System (INIS)

Kusaka, Yuzuru; Tsuji, Haruo; Fujimoto, Yuzo; Ishida, Keiko; Mamuro, Tetsuo.

1980-01-01

An instrumental neutron activation analysis by gamma-ray spectrometry with high resolution and large volume Ge (Li) detectors followed by data processing with an electronic computer was applied to the multielemental analysis to elucidate the chemical qualities of the underground water which has been widely used in the sake brewing industries in Mikage, Uozaki and Nishinomiya districts, called as miyamizu. The evaporated residues of the water samples were subjected to the neutron irradiations in reactor for 1 min at a thermal flux of 1.5 x 10 12 n.cm -2 .sec -1 and for 30 hrs at a thermal flux of 9.3 x 10 11 n.cm -2 .sec -1 or for 5 hrs at a thermal flux of 3.9 x 10 12 n.cm -2 .sec -1 . Thus, 11 elements in the former short irradiation and 38 elements in the latter two kinds of long irradiation can be analyzed. Conventional chemical analysis including atomic absorption method and others are also applied on the same samples, and putting the all results together, some considerations concerning the geochemical meaning of the analytical values are made. (author)

Irradiation chamber and sample changer for biological samples

International Nuclear Information System (INIS)

Kraft, G.; Daues, H.W.; Fischer, B.; Kopf, U.; Liebold, H.P.; Quis, D.; Stelzer, H.; Kiefer, J.; Schoepfer, F.; Schneider, E.

1980-01-01

This paper describes an irradiaton system with which living cells of different origin are irradiated with heavy ion beams (18 <- Z <- 92) at energies up to 10 MeV/amu. The system consists of a beam monitor connected to the vacuum system of the accelerator and the irradiation chamber, containing the biological samples under atmospheric pressure. The requirements and aims of the set up are discussed. The first results with saccharomyces cerevisiae and Chinese Hamster tissue cells are presented. (orig.)

The freezing and thawing of water in poultry meat and vegetables irradiated by electrons at doses of 0.1-4 kGy

International Nuclear Information System (INIS)

Dubini, B.; Montecchia, F.; Ponzi-Bossi, M.G.; Messina, G.

1993-01-01

Poultry meat and some vegetables, irradiated by 5 MeV electrons (0.1-4 kGy), were analysed by differential scanning calorimetry, from 24 h after irradiation. The temperature and enthalpy transitions of the water contained in the irradiated samples were measured and compared with those of unirradiated samples. The authors analysed 18 meat and 10 vegetable samples for each irradiation dose together with a similar number of unirradiated controls. The mean supercooling temperatures of water in the irradiated poultry meat samples and in some vegetables are significantly lower than those of controls. Moreover, the freezing enthalpies of the irradiated poultry breast are significantly lower than those of controls, while they are unchanged in the other cases. The mean ice melting temperatures and enthalpies are similar for all samples. The amount of the lowering of the water-ice transition depends on the nature of the sample and is highest in poultry breast and lowest in vegetables. (author)

Effects of UV irradiation and UV/chlorine co-exposure on natural organic matter in water

International Nuclear Information System (INIS)

Liu, Wei; Zhang, Zaili; Yang, Xin; Xu, Yiyue; Liang, Yongmei

2012-01-01

The effects of co-exposure to ultraviolet (UV) irradiation (with either low- or medium-pressure UV lamps) and free chlorine (chloramine) at practical relevant conditions on changes in natural organic matter (NOM) properties were investigated using four waters. The changes were characterized using the specific disinfection by-product formation potential (SDBPFP), specific total organic halogen formation potential (STOXFP), differential UV absorbance (∆UVA), and size-exclusion chromatography (SEC). The results for exposure to UV irradiation alone and for samples with no exposure were also obtained. The SDBPFPs in all UV-irradiated NOM waters observed were higher than those of non-irradiated samples. UV irradiation led to increases in STOXFPs as a result of chlorination, but no changes, or only small decreases, from chloramination. UV irradiation alone led to positive ∆UVA spectra of the four NOM waters; co-exposure to UV and chlorine gave larger negative ∆UVA spectra than those obtained by chlorine exposure alone. No obvious changes in SEC results were observed for samples only irradiated with UV light; co-exposure gave no detectable changes in the abundances of small fractions for exposure to chlorine only. Both UV photooxidation and photocatalytic oxidation appear to affect the reactivity of the NOM toward subsequent chlorination, and the magnitude of the changes is generally greater for medium-pressure lamps than for low-pressure lamps. These results suggest that applying UV disinfection technology to a particular source may not always be disinfection by-product-problem-free, and the interactions between UV light, chlorine, and NOM may need to be considered. - Highlights: ► We discussed the effects of co-exposure to UV light and chlorine on properties of natural organic matters in waters. ► UV irradiation led to increases in SDBPFP and STOXFP of NOM waters from chlorination. ► We suggest that applying an UV disinfection technology to a particular

Ionizing radiation as optimization method for aluminum detection from drinking water samples

International Nuclear Information System (INIS)

Bazante-Yamguish, Renata; Geraldo, Aurea Beatriz C.; Moura, Eduardo; Manzoli, Jose Eduardo

2013-01-01

The presence of organic compounds in water samples is often responsible for metal complexation; depending on the analytic method, the organic fraction may dissemble the evaluation of the real values of metal concentration. Pre-treatment of the samples is advised when organic compounds are interfering agents, and thus sample mineralization may be accomplished by several chemical and/or physical methods. Here, the ionizing radiation was used as an advanced oxidation process (AOP), for sample pre-treatment before the analytic determination of total and dissolved aluminum by ICP-OES in drinking water samples from wells and spring source located at Billings dam region. Before irradiation, the spring source and wells' samples showed aluminum levels of 0.020 mg/l and 0.2 mg/l respectively; after irradiation, both samples showed a 8-fold increase of aluminum concentration. These results are discussed considering other physical and chemical parameters and peculiarities of sample sources. (author)

Water chemistry of the JMTR IASCC irradiation loop system

International Nuclear Information System (INIS)

Hanawa, Satoshi; Oogiyanagi, Jin; Mori, Yuichiro; Saito, Junichi; Tsukada, Takashi

2006-01-01

Irradiation assisted stress corrosion cracking (IASCC) is recognized as an important degradation issue of the core-internal material for aged Boiling Water Reactors (BWRs). Therefore, irradiation loop system has been developed and installed in the Japan Materials Testing Reactor to perform the IASCC irradiation test. In the IASCC irradiation test, water chemistry of irradiation field is one of the most important key parameters because it affects initiation and propagation of cracks. This paper summarizes the measurement and evaluation method of water chemistry of IASCC irradiation loop system. (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

Raise of efficiency of flocculation-precipitation treatment of exuding water from reclaimed land by irradiation

International Nuclear Information System (INIS)

Sawai, Teruko; Yamazaki, Masao; Sawai, Takeshi

1984-01-01

When rain falls on the coastal reclaimed land filled with home garbage in Tokyo, a large quantity of water containing much organic contaminant flows out. It is difficult to treat this water exuding from reclaimed land by conventional method. Because the water with low BOD which is difficult to treat by biological process flows out for long period after the stabilization of reclaimed land. When the water is treated by flocculation and precipitation, the substances with high molecular weight are easily removed, but the rate of removal of fulvic acid with low molecular weight, which accounts for more than 60% of the composition of the water, is very poor. Therefore, it was examined to change the fulvic acid to high molecular weight by irradiation, and to improve the efficiency of the flocculation-precipitation treatment of exuding water. Exuding water was sampled in Tokyo Bay No.15 reclaimed land, and it was separated into humic acid and fulvic acid. The Co-60 gamma ray of 5 kCi was irradiated to the samples. The experimental method and the results are reported. The change of fulvic acid to high molecular weight by irradiation was most efficient at pH 2.2. More than 90% of organic contaminants was able to be removed. (Kako, I.)

Using Ultraviolet Irradiation for Removal of Malathion Pesticide in Water

Directory of Open Access Journals (Sweden)

M Shayeghi

2012-06-01

Full Text Available Background: Organophosphorus pesticides are one of the most consumable poisons. Such poisons can enter water sources by different routes. Since consuming some drinking water containing an amount of poison higher than the standard level, causes undesirable effects on human health. This research aimed to study the effectiveness of elimi­nating malathion from water by ultraviolet irradiation (UV mercury lamp with a medium pressure.Methods: In this experimental- applied study, variants of initial pHs and initial concentrations and exposure times were investigated. Initial concentrations of malathion were 0.5, 1 and 2 mg/l. The samples were then exposed to UV irradiation interruptedly the time periods of 10, 20, 30, 40, 50 and 60 minutes. The UV lamp used in the reactor was medium pressure (irradiation intensity= 200 W/m2. The amounts of malathion were determined before and after the irradiation by HPLC instrument. Moreover, the results obtained from the study were analyzed using SPSS software and ANOVA and t-test statistical trials.Results: The minimum reduction occurs at 10 min (%46 and the maximum reduction in 60 min (% 87.25 (P< 0.05. In addition, the effectiveness of irradiation process decreases with increasing the poison concentration (P< 0.001. However, the efficiency of the process increases with pH increase.Conclusion: The results show the most effectiveness were achieved at 60 min and 0.5 mg/l and pH= 9. Therefore, the application of UV reactors could be considered as an appropriate method.

Growth of legionella and other heterotrophic bacteria in a circulating cooling water system exposed to ultraviolet irradiation

International Nuclear Information System (INIS)

Kusnetsov, J.M.; Miettinen, I.T.; Martikainen, P.J.; Keskitalo, P.J.; Ahonen, H.E.; Tulkki, A.I.

1994-01-01

The effect of ultraviolet irradiation on the growth and occurrence of legionella and other heterotrophic bacteria in a circulating cooling water system was studied. Water of the reservoir was circulated once in 28 h through a side-stream open channel u.v. radiator consisting of two lamps. Viable counts of legionellas and heterotrophic bacteria in water immediately after the u.v. treatment were 0-12 and 0.7-1.2% of those in the reservoir, respectively. U.v. irradiation increased the concentration of easily assimilable organic carbon. In the u.v. irradiated water samples incubated in the laboratory the viable counts of heterotropic bacteria reached the counts in reservoir water within 5 d. The increase in viable counts was mainly due to reactivation of bacterial cells damaged by u.v. light, not because of bacterial multiplication. Despite u.v. irradiation the bacterial numbers in the reservoir water, including legionellas, did not decrease during the experimental period of 33 d. The main growth of bacteria in the reservoir occurred in biofilm and sediment, which were never exposed to u.v. irradiation. (Author)

Method to determine trace elements in water samples by neutron activation analysis

International Nuclear Information System (INIS)

Kueppers, G.; Erdtmann, G.

1981-05-01

For the determination of trace elements in water by neutron activation analysis irradiation porcedures and chemical separation procedures have been developed. Irradiation in melted quarz glass ampoules in the presence of a platinum wire (for recombination of the oxyhydrogen gas produced by radiolysis) proved successfull with different variants of the irradiation methods, as long irradiation periods without pressure build-up could be achieved. Possible falsifications of the analysis results were investigated in detail (losses by absorption on vessel walls etc.). The irradiated samples can be measured directly with a gamma ray spectrometer and from the radionuclides found the trace element contents may be calculated. More sensitive determinations are possible if the radionuclides are chemically separated. Procedures for removing the matrix activities, for the separation of the radionuclides in groups of elements and for the isolation of single elements have been developed. For especially sensitive determination of some elements selective separation procedures for antimony, cadmium, selenium, mercury and uranium have been developed. The analytical procedures described have been applied to trace element determinations in river water, glacier ice and water solutions from technical processes. (orig./RB) [de

Sampling by electro-erosion on irradiated materials

International Nuclear Information System (INIS)

Riviere, M.; Pizzanelli, J.P.

1986-05-01

Sampling on irradiated materials, in particular for mechanical property study of steels in the FAST NEUTRON program needed the set in a hot cell of a machining device by electroerosion. This device allows sampling of tenacity, traction, resilience test pieces [fr

ESR-based Identification of Radiation-Induced Free Radicals in Gamma-Irradiated Basil and Clove Using Different Sample Pre-Treatments

International Nuclear Information System (INIS)

Kwak, J.Y.; Ahn, J.J.; Kashif Akram; Kwon, J.H.

2012-01-01

An improved detection of radiation-induced paramagnetic faults was developed to identify the irradiation status of basil and clove. The effectiveness of different sample pretreatments, including freeze-drying (FD), oven-drying (OD), alcoholic-extraction (AE), and water-washing and alcoholic-extraction (WAE), were examined. All non-irradiated samples showed a single central signal (g 0 = 2.006), whereas radicals representing two additional side peaks (g 1 = 2.023 and g 2 = 1.986) with a mutual distance of 6 mT were detected in the irradiated samples. AE and WAE produced the best results for irradiated clove in terms of intensities of radiation-specific ESR signals and their ratios to the central signal. However, FD provided the highest intensities of radiation-specific ESR signals for basil, whereas their ratios to the major signal were better in the cases of AE and WAE. Signal noise, particularly due to Mn 2+ signals, was observed, whereas it decreased in AE and WAE pretreatments. Based on our results, AE and WAE can improve the detection conditions for radiation-specific ESR signals in irradiated samples. (author)

Hall effect measurements on proton-irradiated ROSE samples

International Nuclear Information System (INIS)

Biggeri, U.; Bruzzi, M.; Borchi, E.

1997-01-01

Bulk samples obtained from two wafers of a silicon monocrystal material produced by Float-Zone refinement have been analyzed using the four-point probe method. One of the wafers comes from an oxygenated ingot; two sets of pure and oxygenated samples have been irradiated with 24 GeV/c protons in the fluence range from 10 13 p/cm 2 to 2x10 14 p/cm 2 . Van der Pauw resistivity and Hall coefficient have been measured before and after irradiation as a function of the temperature. A thermal treatment (30 minutes at 100C) has been performed to accelerate the reverse annealing effect in the irradiated silicon. The irradiated samples show the same exponential dependence of the resistivity and of the Hall coefficient on the temperature from 370K to 100K, corresponding to the presence of radiation-induced deep energy levels around 0.6-0.7eV in the silicon gap. The free carrier concentrations (n, p) have been evaluated in the investigated fluence range. The inversion of the conductivity type from n to p occurred respectively at 7x10 13 p/cm 2 and at 4x10 13 p/cm 2 before and after the annealing treatment, for both the two sets. Only slight differences have been detected between the pure and oxygenated samples

Characterization and Identification of Gamma-Irradiated Kimchi Cabbage and Broccoli by Electron Spin Resonance Spectroscopy using Different Sample Pre-treatments

International Nuclear Information System (INIS)

Kwak, J.Y.; Ahn, J.J.; Kashif Akram; Kim, G.R.; Kwon, J.H.

2012-01-01

Electron spin resonance (ESR) spectroscopy of gamma-irradiated fresh broccoli and kimchi cabbage was conducted to identify their irradiation history. Different pretreatments, such as freeze-drying (FD), oven-drying (OD), alcoholic-drying (ALD), and water-washing and alcoholic-drying (WAD) were used to lower the moisture contents of the samples prior to ESR analysis. The non-irradiated samples exhibited a single central signal (g 0 = 2.0007) with clear effect of Mn 2+ , especially in kimchi cabbage. Upon irradiation, there was an increase in the intensity of the central signal, and two side peaks, mutually spaced at 6 mT, were also observed. These side peaks with g 1 (left) = 2.023 and g 2 (right) = 1.985 were attributed to radiation-induced cellulose radicals. Leaf and stem in broccoli, and root and stem in kimchi cabbage provided good ESR signal responses upon irradiation. The signal noise was reduced in case of ALD and WAD pretreatments, particularly due to Mn 2+ signals. The ALD treatment was found most feasible to detect the improved ESR spectra in the irradiated samples. (author)

Design of water feeding system for IASCC irradiation tests at JMTR

International Nuclear Information System (INIS)

Kanno, Masaru; Nabeya, Hideaki; Mori, Yuichiro

2001-12-01

In relation to the aging of light water reactors (LWRs), the irradiation assisted stress corrosion cracking (IASCC) has been regarded as a significant and urgent issue for the reliability of in-core components and materials of LWRs, and the irradiation research is now under schedule. It is essential for IASCC studies to irradiated materials under well-controlled conditions simulating LWR in-core environment. Therefore, a new water feeding system to supply high temperature water into irradiation capsules in the Japan Materials Testing Reactor (JMTR) has been designed and will be installed in near future. This report describes the specification and performance of the water feeding system that is designed to supply high temperature water to simulate BWR conditions in irradiation capsules. This design work was performed in the fiscal year 1999. (author)

Irradiation capability of Japanese materials test reactor for water chemistry experiments

International Nuclear Information System (INIS)

Hanawa, Satoshi; Hata, Kuniki; Chimi, Yasuhiro; Nishiyama, Yutaka; Nakamura, Takehiko

2012-09-01

Appropriate understanding of water chemistry in the core of LWRs is essential as chemical species generated due to water radiolysis by neutron and gamma-ray irradiation govern corrosive environment of structural materials in the core and its periphery, causing material degradation such as stress corrosion cracking. Theoretical model calculation such as water radiolysis calculation gives comprehensive understanding of water chemistry at irradiation field where we cannot directly monitor. For enhancement of the technology, accuracy verification of theoretical models under wide range of irradiation conditions, i.e. dose rate, temperature etc., with well quantified in-pile measurement data is essential. Japan Atomic Energy Agency (JAEA) has decided to launch water chemistry experiments for obtaining data that applicable to model verification as well as model benchmarking, by using an in-pile loop which will be installed in the Japan Materials Testing Reactor (JMTR). In order to clarify the irradiation capability of the JMTR for water chemistry experiments, preliminary investigations by water radiolysis / ECP model calculations were performed. One of the important irradiation conditions for the experiments, i.e. dose rate by neutron and gamma-ray, can be controlled by selecting irradiation position in the core. In this preliminary study, several representative irradiation positions that cover from highest to low absorption dose rate were chosen and absorption dose rate at the irradiation positions were evaluated by MCNP calculations. As a result of the calculations, it became clear that the JMTR could provide the irradiation conditions close to the BWR. The calculated absorption dose rate at each irradiation position was provided to water radiolysis calculations. The radiolysis calculations were performed under various conditions by changing absorption dose rate, water chemistry of feeding water etc. parametrically. Qualitatively, the concentration of H 2 O 2 , O 2 and

A new handling tool for irradiated samples at the LENA plant

International Nuclear Information System (INIS)

Alloni, L.; Venturelli, A.

1988-01-01

The handling of neutron irradiated samples at the LENA plant has been so far carried out manually, thus exposing reactor and health physics operators and reactor users to radiation doses. It was then decided to develop an automatic system operated from the reactor console. The system was divided in two sections: one taking care of sample insertion and extraction and the other of the storage of irradiated samples. This paper describes the design and the installation of the storage section. It allows a fast removal of the irradiated samples from the reactor top and their storage in lead pits at the ground level. The extraction of irradiated samples comes out to be quite simplified and radiation doses to operators and users are strongly reduced. All work from design to construction has been carried out by the personnel of the electronic group of the LENA plant

Physical Stability of Oil in Water Emulsions in the Presence of Gamma Irradiated Gum Tragacanth

DEFF Research Database (Denmark)

Meybodi, Neda Mollakhalili; Mohammadifar, Mohammad Amin; Farhoodi, Mehdi

2017-01-01

Gum tragacanth (GT) exuded from an Iranian Astragalus species was γ-irradiated at 0, 0.75, 1.5, 3, 5, 7, 10 kGy and used to stabilize a model oil in water emulsion system. Stability and physicochemical properties of emulsion samples were investigated with respect to the effect of irradiation...... treatment on functional properties of gum tragacanth. Particle size distribution, interfacial tension, zeta potential, steady shear and oscillatory rheological measurements were used to characterize and evaluate the emulsion samples and obtain more information about the possible stability mechanism...

[Efficiency of photodecomposition of trace NDMA in water by UV irradiation].

Science.gov (United States)

Xu, Bing-Bing; Chen, Zhong-Lin; Qi, Fei; Ma, Jun

2008-07-01

Efficiency of photodecomposition of trace NDMA by UV irradiation was investigated with analyzing the initial concentration of NDMA, solution pH, irradiation area, irradiation intensity and water quality effect on NDMA photolysis. NDMA could be effectively photodegraded by UV irradiation. The removal efficiency of NDMA was 97.5% after 5 min of UV irradiation. Effect of initial NDMA concentration on photodecomposition of NDMA was not remarkable. With pH value ascending, the removal rate of NDMA photodecomposition decreased. The yields of photoquantum were more under lower solution pH than that under higher pH. NDMA had fastest reaction rate at solution pH = 2.2. Removal efficiency of NDMA increased with the available irradiation area ascending. Increscent ultraviolet irradiation intensity was good for NDMA degradation. Water quality affected the removal of NDMA slightly. The removal efficiency of NDMA in tap water and Songhua River raw water were 96.7% and 94.8%, respectively.

Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

Energy Technology Data Exchange (ETDEWEB)

Vidal, Lorena [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Domini, Claudia E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grane, Nuria [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Psillakis, Elefteria [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Crete (Greece); Canals, Antonio [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain)]. E-mail: a.canals@ua.es

2007-05-29

A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 {mu}L microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low {mu}g L{sup -1} range varying between 0.016 and 0.039 {mu}g L{sup -1}. Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction.

Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

International Nuclear Information System (INIS)

Vidal, Lorena; Domini, Claudia E.; Grane, Nuria; Psillakis, Elefteria; Canals, Antonio

2007-01-01

A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 μL microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low μg L -1 range varying between 0.016 and 0.039 μg L -1 . Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction

Installation of the water environment irradiation facility for the IASCC research under the BWR irradiation environment (1)

International Nuclear Information System (INIS)

Okada, Yuji; Magome, Hirokatsu; Hanawa, Hiroshi; Ohmi, Masao; Kanno, Masaru; Iida, Kazuhiro; Ando, Hitoshi; Shibata, Mitsunobu; Yonekawa, Akihisa; Ueda, Haruyasu

2013-10-01

In Japan Atomic Energy Agency, in order to solve the problem in the long-term operation of a light water reactor, preparation which does the irradiation experiment of light-water reactor fuel and material is advanced. JMTR stopped after the 165th operation cycle in August 2006, and is advancing renewal of the irradiation facility towards re-operation. This material irradiation test facility and power ramping test facility for doing the neutron irradiation test of the fuel and material for light water reactors is scheduled to be manufactured and installed between the 2008 fiscal year and the 2012 fiscal year. This report summarizes manufacture and installation of the material irradiation test facility for IASCC research carried out from the 2008 fiscal year to the 2010 fiscal year. (author)

Effect of gamma irradiation in 'jongkolnee' water lily

International Nuclear Information System (INIS)

Puripunyavanich, Vichai; Boonsirichai, Kanokporn

2005-10-01

Bulb lets of 'Jongkolnee' water lily irradiated with gamma rays at 0, 50, 100, 150 and 200 grays (20) bulb lets/treatment). All of them were planted in nursery tubs. Ninety percents of the non-irradiated 'Jongkolnee' germinated in 3-4 dyas. The irradiated 'Jongkolnee' germinated in 5, 7, 10 and 14 days and their germination ratios were 75%, 50%, 30% and 10% respectively. Later, they were transplanted into water lily pots. irradiated 'Jongkolnee' were grew slower than non irradiated 'Jongkolnee' and some irradiated plants died in the first 3 months. Healthy plants were transplanted in bigger pots. When they flowered, two nutnat characteristics were transplanted into bigger pots. When they flowered, two mutant characteristics were discovered: one with white petals and one with purple petals. However, the white 'Jongkolnee' flower shape was abnormal bad, therefore, bulb lets of white 'Jongkolnee' will be plant for selecting in the next generation. On the other hand, the purple 'Jongkolnee' flower shape was similar to the original pink one. the purple 'Jongkolnee' will be used for further studies in the future

Luminescence imaging of water during carbon-ion irradiation for range estimation

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Komori, Masataka; Koyama, Shuji; Morishita, Yuki; Sekihara, Eri [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Akagi, Takashi; Yamashita, Tomohiro [Hygo Ion Beam Medical Center, Hyogo 679-5165 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

2016-05-15

Purpose: The authors previously reported successful luminescence imaging of water during proton irradiation and its application to range estimation. However, since the feasibility of this approach for carbon-ion irradiation remained unclear, the authors conducted luminescence imaging during carbon-ion irradiation and estimated the ranges. Methods: The authors placed a pure-water phantom on the patient couch of a carbon-ion therapy system and measured the luminescence images with a high-sensitivity, cooled charge-coupled device camera during carbon-ion irradiation. The authors also carried out imaging of three types of phantoms (tap-water, an acrylic block, and a plastic scintillator) and compared their intensities and distributions with those of a phantom containing pure-water. Results: The luminescence images of pure-water phantoms during carbon-ion irradiation showed clear Bragg peaks, and the measured carbon-ion ranges from the images were almost the same as those obtained by simulation. The image of the tap-water phantom showed almost the same distribution as that of the pure-water phantom. The acrylic block phantom’s luminescence image produced seven times higher luminescence and had a 13% shorter range than that of the water phantoms; the range with the acrylic phantom generally matched the calculated value. The plastic scintillator showed ∼15 000 times higher light than that of water. Conclusions: Luminescence imaging during carbon-ion irradiation of water is not only possible but also a promising method for range estimation in carbon-ion therapy.

Luminescence imaging of water during carbon-ion irradiation for range estimation

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Morishita, Yuki; Sekihara, Eri; Akagi, Takashi; Yamashita, Tomohiro; Toshito, Toshiyuki

2016-01-01

Purpose: The authors previously reported successful luminescence imaging of water during proton irradiation and its application to range estimation. However, since the feasibility of this approach for carbon-ion irradiation remained unclear, the authors conducted luminescence imaging during carbon-ion irradiation and estimated the ranges. Methods: The authors placed a pure-water phantom on the patient couch of a carbon-ion therapy system and measured the luminescence images with a high-sensitivity, cooled charge-coupled device camera during carbon-ion irradiation. The authors also carried out imaging of three types of phantoms (tap-water, an acrylic block, and a plastic scintillator) and compared their intensities and distributions with those of a phantom containing pure-water. Results: The luminescence images of pure-water phantoms during carbon-ion irradiation showed clear Bragg peaks, and the measured carbon-ion ranges from the images were almost the same as those obtained by simulation. The image of the tap-water phantom showed almost the same distribution as that of the pure-water phantom. The acrylic block phantom’s luminescence image produced seven times higher luminescence and had a 13% shorter range than that of the water phantoms; the range with the acrylic phantom generally matched the calculated value. The plastic scintillator showed ∼15 000 times higher light than that of water. Conclusions: Luminescence imaging during carbon-ion irradiation of water is not only possible but also a promising method for range estimation in carbon-ion therapy.

Tube closure device, especially for sample irradiation

International Nuclear Information System (INIS)

Klahn, F.C.; Nolan, J.H.; Wills, C.

1979-01-01

Device for closing the outlet of a bore and temporarily locking components in this bore. Specifically, it concerns a device for closing a tube containing a set of samples for monitoring irradiation in a nuclear reactor [fr

Inert medium (helium) irradiation testing of pressure tube samples

International Nuclear Information System (INIS)

Ancuta, M.; Radu, V.; Stefan, V.; Preda, M.

2001-01-01

Irradiation tests currently performed in C-5 capsule aim at obtaining data and information concerning behavior to irradiation of pressure tubes of CANDU type fuel channel, to evidence the factors limiting operation life span. A calculation code for analysis and prediction of pressure tube behavior should be based upon periodical inspection results, post irradiation examination of the removed from reactor pressure tubes as well as on the experimental results obtained with materials subjected to irradiation conditions identical with the operational ones. Mechanical behavior analysis should focus both complex thermal-mechanical type stresses and mechanical properties alteration under irradiation. The experimental results should be applied: - to evaluate the irradiation effects upon mechanical properties of Zr-2.5% Nb exposed to fluences up to 10 21 n·cm -2 ; - to gather data concerning the real stress / real deformation characteristic from which characteristic quantities can be deduced as, for instance, elasticity modulus, plasticity modulus, exponent of stress term in the Tsu-Berteles relation, to be used within the CANTUP simulation code describing pressure tube behavior, currently developed at INR Pitesti; - to develop prediction methods of pressure tube behavior and merging with in-service inspection procedure in order to forecast the life span and the proper timing for replacement before major failures occur. The samples irradiated in C-5 capsule were extracted from the ends of Zr-2.5% Nb pressure tubes resulting from Cernavoda NPP Unit 1. The samples for tensile tests were extracted on longitudinal and transversal directions of the pressure tube. The tests were carried out under following conditions: - test environment temperature, 260 - 280 deg.C; - testing medium, helium at 1 - 6 b pressure; - neutron flux (E n > 1 MeV), 1 - 2 · 10 13 ncm -2 s -1 ; - neutron fluence (E n > 1 MeV), 4 · 10 20 ncm -2 . The following characteristics were obtained from tensile

Luminescence imaging of water during alpha particle irradiation

Science.gov (United States)

Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Toshito, Toshiyuki

2016-05-01

The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of 241Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

Luminescence imaging of water during alpha particle irradiation

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Komori, Masataka; Koyama, Shuji [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

2016-05-21

The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of {sup 241}Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

Water radiolysis in a crack tip under gamma ray irradiation

International Nuclear Information System (INIS)

Satoh, Tomonori; Uchida, Shunsuke; Satoh, Yoshiyuki

2002-01-01

Under a non-irradiation condition, oxidant, e.g., O 2 and H 2 O 2 , in a crack tip is supplied from the bulk water. But under irradiation conditions, even if the diffusion of radiolytic species is not sufficient, direct radiolysis in the crack tip causes high concentrations of radiolytic species. As a result of measurements and Monte Carlo calculation of gamma ray energy deposition, it has been confirmed that the energy deposition rate in the gap water is larger than that in the bulk water. The energy absorption rate increases as the gap width decreases and reaches 1.3 times that in the bulk water. In order to evaluate crack propagation rate for irradiation assisted stress corrosion cracking (IASCC) of stainless steel, a water radiolysis model in a crevice is proposed. A larger energy deposition rate in the crevice water produces many more radiolytic species, which causes high oxidant concentrations in spite of enhanced recombination of the species at the crevice inner surface. So, for IASCC evaluation, crevice water chemistry plays an important role to determine the crack propagation rate under irradiation. (authors)

Neutron-Irradiated Samples as Test Materials for MPEX

International Nuclear Information System (INIS)

Ellis, Ronald James; Rapp, Juergen

2015-01-01

Plasma Material Interaction (PMI) is a major concern in fusion reactor design and analysis. The Material-Plasma Exposure eXperiment (MPEX) will explore PMI under fusion reactor plasma conditions. Samples with accumulated displacements per atom (DPA) damage produced by fast neutron irradiations in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) will be studied in the MPEX facility. This paper presents assessments of the calculated induced radioactivity and resulting radiation dose rates of a variety of potential fusion reactor plasma-facing materials (such as tungsten). The scientific code packages MCNP and SCALE were used to simulate irradiation of the samples in HFIR including the generation and depletion of nuclides in the material and the subsequent composition, activity levels, gamma radiation fields, and resultant dose rates as a function of cooling time. A challenge of the MPEX project is to minimize the radioactive inventory in the preparation of the samples and the sample dose rates for inclusion in the MPEX facility

An automatic device for sample insertion and extraction to/from reactor irradiation facilities

International Nuclear Information System (INIS)

Alloni, L.; Venturelli, A.; Meloni, S.

1990-01-01

At the previous European Triga Users Conference in Vienna,a paper was given describing a new handling tool for irradiated samples at the L.E.N.A plant. This tool was the first part of an automatic device for the management of samples to be irradiated in the TRIGA MARK ii reactor and successively extracted and stored. So far sample insertion and extraction to/from irradiation facilities available on reactor top (central thimble,rotatory specimen rack and channel f),has been carried out manually by reactor and health-physics operators using the ''traditional'' fishing pole provided by General Atomic, thus exposing reactor personnel to ''unjustified'' radiation doses. The present paper describes the design and the operation of a new device, a ''robot''type machine,which, remotely operated, takes care of sample insertion into the different irradiation facilities,sample extraction after irradiation and connection to the storage pits already described. The extraction of irradiated sample does not require the presence of reactor personnel on the reactor top and,therefore,radiation doses are strongly reduced. All work from design to construction has been carried out by the personnel of the electronic group of the L.E.N.A plant. (orig.)

Effects of γ-radiation on microbial load and antioxidant proprieties in green tea irradiated with different water activities

International Nuclear Information System (INIS)

Fanaro, G.B.; Hassimotto, N.M.A.; Bastos, D.H.M.; Villavicencio, A.L.C.H.

2015-01-01

The aim of this paper is to study the effect of gamma radiation on green tea irradiated with different water activities. The green tea samples had their Aw adjusted to three values (0.93, 0.65, and 0.17) and were irradiated in 60 Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The methods used were: microbiology, total phenolic compounds quantification, antioxidant activity by ORAC, and quantification of the main antioxidants. It was observed that the greater the amount of free water present in the samples, lower was the dose to achieve microbiological control. Despite the irradiation with 5.0 kGy with high water activity has a small decrease in phenolic compounds and in some catechins content, this condition is recommended once was the dose to ensure microbiological safety without interfering in the main catechins and the antioxidant activity. - Highlights: • Higher the Aw, lower is the radiation dose to archive microbiology safety. • The doses up to 10.0 kGy had no effect on antioxidant capacity in all Aw used. • The recommended dose to irradiated green tea is 5.0 kGy

Irradiation test of mirror samples for the LHCb SciFi tracker

CERN Document Server

Joram, Christian; Gavardi, Laura; Ravotti, Federico; Schneider, Thomas

2016-01-01

The optical mirrors at the inner ends of the SciFi fibre modules in the upgraded LHCb detector will be exposed to an ionising dose reaching 35 kGy for an integrated luminosity of 50 /fb. This note describes a campaign at the cyclotron at KIT where 7 different samples were irradiated with 23 MeV protons. The samples consisted of plastic scintillator tiles, on which two different mirror foils – aluminised mylar and 3M ESR - were attached with two different glues – Epotek H301-2FL and Dow Corning RTV 3145. The transmission and/or reflectivity of the samples were measured before and after irradiation. The measurements reveal the combination of 3M ESR foil and Epotek H301-2FL to give the highest reflectivity, before and also after irradiation. In all cases, the irradiation leads only to a small, i.e. less than 10%, degradation of the transmission or reflectivity. From a radiation hardness point of view, all investigated mirror samples qualify for use in the SciFi detector.

Oxidative stability examination of irradiated swine for samples

International Nuclear Information System (INIS)

Formanek, Z.

1995-01-01

DSC (Differential Scanning Calorimetry), OBM (Oxygen Bomb Method) methods and POV (Peroxide Value) determination was applied to determine the oxidative stability of lard samples irradiated by a Co 60 gamma source at the dose of 0; 0.75; 2.5kGy. Both of the methods seem to be suitable to determine oxidative stability of fats, because in every case lowering oxidative stability was received with increasing irradiation dose. (R.P.). 8 refs., 7 figs., 1 tab

Influence of irradiation conditions on the gamma irradiation effect in polyethylene

International Nuclear Information System (INIS)

Kacarevic-Popovic, Z.; Gal, O.; Novakovic, L.J.; Secerov, B.

2002-01-01

Complete text of publication follows. The radiation cross-linking of polyethylene, due to its high cross-linking yield, has resulted in the radiation technology that has found application in radiation production of heat shrinkable structures and in improvement of mechanical and thermo-physical properties of oriented polyethylene objects. It is observed that the cross-linking efficiency decreases when the irradiation is carried out in the presence of oxygen. In order to estimate the conditions that improve cross-linking efficiency, gamma irradiation effect in two types of polyethylene, irradiated in water and air was investigated. The polyethylene samples used were the low density (LDPE) Lotrene CdF 0302 with 45% crystallinity and the high density (HDPE) Hiplex EHM 6003 with 73% crystallinity. Both kinds of samples, fixed in the Pyrex glass tubes, were simultaneously irradiated with 60 Co gamma rays in distilled water and air, at a doses rate of 9,5 kGy/h (determined by the Fricke dosimeter) at room temperature. Radiation induced oxidative degradation was followed through oxygen containing group formation by the carbonyl group band (1720 cm -1 ) and transvinylene group formation by the band at 966 cm -1 in the infrared spectra. Cross-linking efficiency was determined by gel content using the procedure of the extraction in xylene. The monitored effects of gamma irradiation in water and air point to the conclusion that irradiation in water leads to the lower oxidative degradation and higher cross-linking compared with the effects measured after irradiation in air

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

International Nuclear Information System (INIS)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-01-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed

Effect of interaction between irradiation-induced defects and intrinsic defects in the pinning improvement of neutron irradiated YBaCuO sample

Energy Technology Data Exchange (ETDEWEB)

Topal, Ugur; Sozeri, Huseyin; Yavuz, Hasbi

2004-08-01

Interaction between the intrinsic (native) defects and the irradiation-induced defects created by neutron irradiation was examined for the YBCO sample. For this purpose, non-superconducting Y-211 phase was included to the Y-123 samples at different contents as a source of large pinning center. The critical current density enhancement with the irradiation for these samples were analysed and then the role of defects on pinning improvement was discussed.

Database of Samples Irradiated at Reactor TRIGA PUSPATI (RTP)

International Nuclear Information System (INIS)

Muhd Husamuddin Abdul Khalil; Mohd Amin Sharifuldin Salleh; Julia Abdul Karim

2011-01-01

Evaluation has been made to data of irradiated samples for the type of sample requested for activation at RTP. Sample types are grouped with percentage of total throughputs to rule out the weight percent of every respective group. The database consists of radionuclide inventory of short and long half-life and high activity radionuclides such as Br and Au have been identified and that database has been constructed using a user-friendly Microsoft Access. Through this, trend of gamma exposure will easily be evaluated at experimental facilities and could ensure radiological effect towards safety and health is limited per Radiation Protection (Basic Safety Standard) Regulation 1988. This database places an important parameter to improve management system in acquiring information of the samples irradiated at RTP and will enhance the safety assurance and reliability of the experimental design basis. (author)

Irradiation degradation of chlorpyrifos in water solution and asparagus

International Nuclear Information System (INIS)

Zhang Qingfang; Wang Feng; Ha Yiming; Li An; Yin Qinggang

2009-01-01

In order to seek an effective technique to degrade chlorpyrifos residue, chlorpyrifos water solution and asparagus containing chlorpyrifos as testing materials were irradiated by 60 Co γ-rays and their degradation rate were determined and compared. The results show the degradation rate in water-solution increases with irradiation dose in the range of 0 and 12 kGy, and it reached 95.5% at 4 kGy. The degradation rate of chlorpyrifos in asparagus is low and comes to the maximum of 30.0% when the dose is 8 kGy. Further study indicates that vitamin C, violaquercitrin and total sugar inhibit the irradiation degradation of chlorpyrifos in asparagus. (authors)

Pre-feasibility study of electron beam irradiation of fresh water

International Nuclear Information System (INIS)

Finshi V, Silvia.

1997-01-01

A technical/economic evaluation of electron beam irradiation for the decontamination of liquids in the country is presented. Irradiation of fresh water is evaluated for the production of drinking water as a replacement for chlorine disinfection, which can lead to the formation of tri halo methanes. that are carcinogenic compounds. The technical literature states that the percentage of microorganisms removed by electro beam irradiation is high and similar to that found with chlorine disinfection. From an economic point of view, irradiation technology is not presently competitive as an alternative to conventional chlorination in terms of processing costs (US$0.23/m 3 ) instead of US$0.013/m 3 for conventional chlorination. Nevertheless, irradiation costs decreased sharply when unit costs for the accelerator machine are decreased with a resulting drop in capital costs

Study of the iron corrosion at the interface of different media (water, air) submitted to protons irradiation

International Nuclear Information System (INIS)

Lapuerta, S.

2005-10-01

During the deep geological disposal, stainless steel containers of the vitrified waste will be put in carbon steel overpacks. After the closing of the storage site, overpacks will be in contact with a humid air and a radioactive medium. After hundred years, overpacks could be in contact with water radiolysis in an anoxic medium. In this context, my PhD work is a fundamental study which is the understanding of the corrosion mechanisms of pure iron under proton irradiation. This corrosion is affected by the contact of iron with different atmospheres (air, nitrogen) and water. In the case of the atmospheric iron corrosion under irradiation, we have studied the influence of the proton beam flux. During this work, we have characterized the structure of the oxides formed at the iron surface. The structure formed does not correspond to iron oxides and hydroxides indexed. However, we have shown that the oxide structure is close to that of lepidocrocite and bernalite. Moreover, we have determined the oxygen diffusion coefficient in iron under irradiation and we have shown that the irradiation accelerates of 6 orders of magnitude the iron corrosion. In addition, the irradiations which were realized in different gas have put in evidence the negligible role of nitrates, and the importance of the O 2 /H 2 O coupling on the iron corrosion. Finally, we have shown the influence of the relative humidity, the maximum of the corrosion being observed for a relative humidity close to 45%. In the case of the iron corrosion in aqueous media under irradiation, the influence of the oxygen dissolved in water has been studied using a surface marker. We have put in evidence that the corrosion is twice more significant in aerated medium than in deaerated medium. Moreover, the influence of radicals has been shown. An irradiated sample is more corroded than a sample put in contact with a H 2 O 2 solution. Finally, the follow-up of the iron potential under irradiation have shown the majority role

Luminescence imaging of water during proton-beam irradiation for range estimation

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya 462-8508 (Japan)

2015-11-15

Purpose: Proton therapy has the ability to selectively deliver a dose to the target tumor, so the dose distribution should be accurately measured by a precise and efficient method. The authors found that luminescence was emitted from water during proton irradiation and conjectured that this phenomenon could be used for estimating the dose distribution. Methods: To achieve more accurate dose distribution, the authors set water phantoms on a table with a spot scanning proton therapy system and measured the luminescence images of these phantoms with a high-sensitivity, cooled charge coupled device camera during proton-beam irradiation. The authors imaged the phantoms of pure water, fluorescein solution, and an acrylic block. Results: The luminescence images of water phantoms taken during proton-beam irradiation showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. Furthermore, the image of the pure-water phantom showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of the fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had a 14.5% shorter proton range than that of water; the proton range in the acrylic phantom generally matched the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 s. Conclusions: Luminescence imaging during proton-beam irradiation is promising as an effective method for range estimation in proton therapy.

Luminescence imaging of water during proton-beam irradiation for range estimation

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Okumura, Satoshi; Komori, Masataka; Toshito, Toshiyuki

2015-01-01

Purpose: Proton therapy has the ability to selectively deliver a dose to the target tumor, so the dose distribution should be accurately measured by a precise and efficient method. The authors found that luminescence was emitted from water during proton irradiation and conjectured that this phenomenon could be used for estimating the dose distribution. Methods: To achieve more accurate dose distribution, the authors set water phantoms on a table with a spot scanning proton therapy system and measured the luminescence images of these phantoms with a high-sensitivity, cooled charge coupled device camera during proton-beam irradiation. The authors imaged the phantoms of pure water, fluorescein solution, and an acrylic block. Results: The luminescence images of water phantoms taken during proton-beam irradiation showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. Furthermore, the image of the pure-water phantom showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of the fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had a 14.5% shorter proton range than that of water; the proton range in the acrylic phantom generally matched the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 s. Conclusions: Luminescence imaging during proton-beam irradiation is promising as an effective method for range estimation in proton therapy

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

Effects of γ-radiation on microbial load and antioxidant proprieties in black tea irradiated with different water activities

International Nuclear Information System (INIS)

Fanaro, G.B.; Hassimotto, N.M.A.; Bastos, D.H.M.; Villavicencio, A.L.C.H.

2014-01-01

The aim of this paper is to study the effect of gamma radiation on black tea irradiated with different water activities. The black tea samples had their Aw adjusted to three values (0.92, 0.65, and 0.18) and were irradiated in 60 Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The methods used were: microbiology, total phenolic compounds quantification, antioxidant activity by ORAC, and quantification of the main antioxidants. It was observed that the greater the amount of free water present in the samples, lower was the dose to achieve microbiological control. Regardless the water activity used, there was no difference in content of the phenolic compounds and at the mainly theaflavins, as well in the antioxidant activity at doses up to 5.0 kGy. - Highlights: • Higher the Aw, lower is the radiation dose to archive microbiology safety. • The doses up to 10.0 kGy had no effect on antioxidant capacity in all Aw used. • The recommended dose to irradiated black tea is 5.0 kGy

Two specialized delayed-neutron detector designs for assays of fissionable elements in water and sediment samples

International Nuclear Information System (INIS)

Balestrini, S.J.; Balagna, J.P.; Menlove, H.O.

1976-01-01

Two specialized neutron-sensitive detectors are described which are employed for rapid assays of fissionable elements by sensing for delayed neutrons emitted by samples after they have been irradiated in a nuclear reactor. The more sensitive of the two detectors, designed to assay for uranium in water samples, is 40% efficient; the other, designed for sediment sample assays, is 27% efficient. These detectors are also designed to operate under water as an inexpensive shielding against neutron leakage from the reactor and neutrons from cosmic rays. (Auth.)

Installation of the water environment irradiation facility for the IASCC research under the BWR/PWR irradiation environment (2)

International Nuclear Information System (INIS)

Magome, Hirokatsu; Okada, Yuji; Hanawa, Hiroshi; Sakuta, Yoshiyuki; Kanno, Masaru; Iida, Kazuhiro; Ando, Hitoshi; Yonekawa, Akihisa; Ueda, Haruyasu; Shibata, Mitsunobu

2014-07-01

In Japan Atomic Energy Agency, in order to solve the problem in the long-term operation of a light water reactor, preparation which does the irradiation experiment of light-water reactor fuel and material was advanced. JMTR stopped after the 165th operation cycle in August 2006, and is advancing renewal of the irradiation facility towards re-operation. The material irradiation test facility was installed from 2008 fiscal year to 2012 fiscal year in JMTR. This report summarizes manufacture and installation of the material irradiation test facility for IASCC research carried out from 2012 to 2014 in the follow-up report reported before (JAEA-Technology 2013-019). (author)

Container for gaseous samples for irradiation at accelerators

International Nuclear Information System (INIS)

Kupsch, H.; Riemenschneider, J.; Leonhardt, J.

1985-01-01

The invention concerns a container for gaseous samples for the irradiation at accelerators especially to generate short-lived radioisotopes. The container is also suitable for storage and transport of the target gas and can be multiply reused

The effect of combination treatment of gamma irradiation with refrigeration or with hot water treatment on the storage life and organoleptic properties of carabao mangoes and lacatan bananas

International Nuclear Information System (INIS)

Barruel, D.S.

1976-03-01

This study aims to determine the best combination of irradiation-hot water and irradiation-low temperature storage as treatments to help achieve longer shelf-life extension of fruits with export value such as bananas and mangoes. Results have shown the combined irradiation and hot water treatment as a better treatment for mangoes over that of combined irradiation (50kr) and low temperature storage (15 0 C) or of single treatments with irradiation, refrigeration or hot water. A much lower dose of 30 krad was found to give the longest extension in shelf-life in mangoes subjected to irradiation and hot (55 0 C) water treatment. No significant differences in the organoleptic properties were found in the samples given the combination treatment when compared to samples given no treatment at all. The extension in shelf-life may be attributed to the synergistic effect of the treatments, which could have affected the senescence of the fruit and likewise controlled the growth of rot-causing microorganisms. Similar work was also done on bananas but the results are still preliminary

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self-adhesive resin cement.

Science.gov (United States)

Takenaka, Hirotaka; Ouchi, Hajime; Sai, Keiichi; Kawamoto, Ryo; Murayama, Ryosuke; Kurokawa, Hiroyasu; Miyazaki, Masashi

2015-08-14

Self-adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self-adhesive resin cement. A self-adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light-irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light-irradiated, the sonic velocity rapidly increased and plateaued at 2,500-2,700 m s -1 . When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self-adhesive resin cements is affected by the polymerization mode and the presence of water. © 2015 Eur J Oral Sci.

Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation.

Science.gov (United States)

Polf, Jerimy C; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

2013-09-07

The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.

Irradiated accelerated corrosion of stainless steel

International Nuclear Information System (INIS)

Raiman, S.S.; Wang, P.; Was, G.S.

2015-01-01

Type 316L stainless steel was exposed to a simulated PWR environment with in-situ proton irradiation to investigate the effect of simultaneous irradiation and corrosion. To enable these experiments, a dedicated beamline was constructed to transport a 3.2 MeV proton beam from a tandem accelerator, through the sample that also acts as the window between the beamline vacuum and a corrosion cell designed to flow primary water at 320 C. degrees and 13.1 MPa. Experiments were conducted on 316L stainless steel samples which were irradiated for 24 hours in 320 C. degrees water with 3 ppm H 2 , at dose rates of 7*10 -6 dpa/s and 7*10 -7 dpa/s, for 4, 24, and 72 hours. A dual-layer oxide formed on the samples, with an inner layer rich in Cr with Fe and Ni content, and an outer layer of Fe oxides. Samples were characterized with TEM (Transmission Electron Microscopy), EDS, and Raman spectroscopy to determine the effect of irradiation. Irradiated samples were found to have a thinner and more porous inner oxide which was deficient in chromium. The outer oxide was found to have significant hematite content, suggesting that irradiation led to an increase in ECP (Electro-Chemical Potential) at the oxide-solution interface, causing accelerated dissolution of the oxide under irradiation. (authors)

Irradiation of Oil / Water Biphasic Systems: the Importance of Interfacial Surface Area on the Production of Hydrogen and Other Deleterious Products

International Nuclear Information System (INIS)

Causey, Patrick-W.; Stuart, Craig-R.

2012-09-01

interfacial surface area, control of headspace gas composition, and removal of sample aliquots. Results highlight the importance of interfacial surface area in affecting the radiolytic degradation of the studied hydrocarbons. In particular, experiments having higher oil-water interfacial surface areas generate greater quantities of oil degradation products as compared with lower surface area samples. As expected, one notable result from these irradiations was the formation of significant quantities of hydrogen, which was found to be dependent on the interfacial surface area. Presented here is a review of the radiolytic degradation of insoluble organic material in aqueous systems, a summary of experimental results focusing on biphasic systems and a description of a strategy to mitigate the effects of insoluble organic material ingress and to aid in developing station-appropriate responses. (authors)

Effect of gamma irradiation on the storage and vitamin C concentration of allium cepa onion samples

International Nuclear Information System (INIS)

Saleh, M. A. M.

2013-07-01

This study was done to investigate the effect of gamma irradiation on storage, germination and vitamin C concentration of local onion (Allium cepa). 5 onion samples were irradiated with 5 different radiation doses (0.1, 0.2, 0.3, 0.4, and 0.5 k Gray) using cobalt-60 irradiator (Nor din) compared to non irradiated samples as controls. The irradiated and control onions were stored at room temperature for three months. The results of this study showed that the non irradiated samples were either deteriorated or grown while all the irradiated samples were not. Regarding the concentration of vitamin C it was clear that it decreased with the dose increase from 30.53 to 14.44 mg/100 g. This study concluded that the irradiation is very effective in prevention of spoilage, elongation of germination period and decrease of vitamin C concentration.(Author)

Water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels

Energy Technology Data Exchange (ETDEWEB)

Wang, Qingguo, E-mail: qwang@qust.edu.cn [Key Laboratory of Rubber-Plastics of Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao 266042 (China); Zhou, Xue; Zeng, Jinxia; Wang, Jizeng [Key Laboratory of Rubber-Plastics of Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China)

2016-02-01

In this paper, the electron beam irradiation technology being more suitable for the industry application is explored to fabricate the acrylic acid (AAc) monomer-grafted polyvinyl alcohol (PVA-g-AAc) hydrogels. ATR-IR spectra of the PVA-g-AAc hydrogels shows an obvious absorption peak of the −C=O group at 1701 cm{sup −1}, indicating that the AAc monomers were grafted onto the PVA macromolecules. This paper also studied some effects of the mass ratio of PVA/AAc, pH of buffer solution and irradiation dosage on the water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels. The water swelling ratio of PVA-g-AAc hydrogels decreases with increased irradiation dosage and mass ratio of PVA/AAc, whereas swelling ratio increases with increased pH of buffer solution and soaking time. The water-swelling behavior of PVA-g-AAc hydrogels occurred easily in an alkaline environment, particularly in a buffer solution with pH 9.2. Both PVA-g-AAc hydrogels (PVA/AAc = 1/5, w/w) irradiated with 5 kilogray (kGy) and PVA-g-AAc hydrogels (PVA/AAc = 1/1, w/w) irradiated with 15 kGy could easily absorb water and lead to high water swelling ratios (up to about 600%), which are potential candidates to meet the requirements for some biomedical applications.

Evaluation of lyophilization for the preconcentration of natural water samples prior to neutron activation analysis

International Nuclear Information System (INIS)

Harrison, S.H.; LaFleur, P.D.; Zoller, W.H.

1975-01-01

Water is preconcentrated by freeze drying using a method which virtually eliminates sample contamination and trace element losses. To test the possibility of losses of volatile elements during the drying process, known quantities of radioactive tracers for 21 elements were added to water, the solutions freeze dried, and the tracer residues counted. The results confirm that at least 95 percent of all but the most volatile elements studied (Hg and I) were retained in the residue. The problem of transferring quantitatively the dry residue from the freeze drying container to an irradiation container was eliminated by designing a freeze drying container that would also serve as an irradiation and counting container. (U.S.)

Improvement of physical properties of soyabeans by gamma irradiation

International Nuclear Information System (INIS)

Byun, M.-W.; Kwon, J.-H.; Mori, Tomohiko

1993-01-01

Physical properties of gamma-irradiated soybeans were evaluated at different temperatures by determining water absorption pattern and cooking characteristics of the sample. Irradiation at 2.5-10 kGy caused the reduction of soaking time in soybeans by 2-5 hours and the increase of hydration capacity by 10-20%, respectively, compared to the non-irradiated control at 20 o C. The activation energy for water absorption was lower in irradiated soybeans than in the non-irradiated control. Irradiation at 2.5-10 kGy caused the reduction of cooking time in soybeans by 30-60% compared to the non-irradiated control and the cooking rate constant of irradiated samples was higher about 2 times than that of the non-irradiated control. The irradiation efficacy on physical quality improvement was also recognized in the stored soybeans for one year at room temperature. (author)

Storage pool water condition of multipurpose compact 60Co irradiator of IPEN-CNEN/SP

International Nuclear Information System (INIS)

Kodama, Yasko; Rela, Paulo R.

2008-01-01

states that conductivity must be maintained between 1.0 and 10.0 microsiemens per centimeter (μS/cm). This will reduce the possibility of corrosion of the sealed source. Extreme care shall be exercised to avoid the introduction of contaminants into the water system (e.g. deionized regenerants, cleaning materials, corrosive fire extinguishing materials, spilled product). However, conductivity may increase to 20 μS/cm during occasions such as water treatment plant servicing or source loadings. Also, conductivity may occasionally decrease to 0.5 μS/cm. The desired operating conditions for pH ranges from 4.5 or 5.5 to 8.5, depending on the sealed source manufacturer specification. In this work, four points from storage poll samples and one from water treatment system of multipurpose compact irradiator were collected monthly in the last three years. The pH and conductivity measurements were performed on the every collected sample. All the conductivity values were below the stated limit even just before treatment column exchange, which occurred twice in the period considered here. Despite of pH measured values being very close to the inferior limit of 5.5., in practice, when conductivity specifications are met, pH is less important because the water is so pure that very low levels of contaminants may greatly affect the measurements. (author)

Preliminary analysis on the water quality index (WQI) of irradiated basic filter elements

Science.gov (United States)

Arif Abu Bakar, Asyraf; Muhamad Pauzi, Anas; Aziz Mohamed, Abdul; Syima Sharifuddin, Syazrin; Mohamad Idris, Faridah

2018-01-01

Simple water filtration system is needed in times of extreme floods. Clean water for sanitation at evacuation centres is essential and its production is possible by using the famous simple filtration system consisting of empty bottle and filter elements (sands, gravels, cotton/coffee filter). This research intends to study the effects of irradiated filter elements on the filtration effectiveness through experiments. The filter elements will be irradiated with gamma and neutron radiation using the facilities available at Malaysia Nuclear Agency. The filtration effectiveness is measured using the water quality index (WQI) that is developed in this study to reflect the quality of filtered water. The WQI of the filtered water using the system with irradiated filter elements is then compared with that of the system with non-irradiated filter elements. This preliminary analysis only focus on filtration element of silica sand. Results shows very nominal variation in in WQI after filtered by non-irradiated, gamma and neutron filter element (silica sand), where the hypothesis could not be affirmed.

Change of microflora of two starch samples by gamma irradiation

International Nuclear Information System (INIS)

Fretton, R.; Fretton, J.; Delattre, J.M.

1975-01-01

Starch is the basic component of a larger number of manufactured foods. The disinfection of such a powder by 60 Co is studied here. Gamma irradiation of two starch samples with different degrees of contamination allows the assumption that, in most cases, good radio-pasteurization can be achieved with 300 krad. The radio-pasteurization doses (varying from 300 to 600 krad) are a function of the initial contamination. Irradiation effects are spectacular with moulds. Activation of spores of some Clostridium species leads us to recommend an irradiation level higher than 200 krad. The most resistant organisms to gamma irradiation are the aerobic and anaerobic sporulated bacteria. The thermophilic forms are the most important. Spores of Bacillus, chiefly Bacillus licheniformis and Bacillus brevis, are the most frequent bacteria. Storage of irradiated starch at room temperature has little effect upon the number of revivable survivors. (orig.) [de

Advanced post-irradiation examination techniques for water reactor fuel. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

2002-03-01

The purpose of the meeting was to provide and overview of the status of post-irradiation examination (PIE) techniques for water cooled reactor fuel assemblies and their components with emphasis given to advanced PIE techniques applied to high burnup fuel. Papers presented at the meeting described progress obtained in non-destructive (e.g. dimensional measurements, oxide layer thickness measurements, gamma scanning and tomography, neutron and X-ray radiography, etc.) and destructive PIE techniques (e.g. microstructural studies, elemental and isotopic analysis, measurement of physical and mechanical properties, etc.) used for investigation of water reactor fuel. Recent practice in high burnup fuel investigation revealed the importance of advanced PIE techniques, such as 3-D tomography, secondary ion mass spectrometry, laser flash, high resolution transmission and scanning electron microscopy, image analysis in microstructural studies, for understanding mechanisms of fuel behaviour under irradiation. Importance and needs for in-pile irradiation of samples and rodlets in instrumented rigs were also discussed. This TECDOC contains 20 individual papers presented at the meeting; each of the papers has been indexed separately

Import control of irradiated foods by the thermoluminescence method

International Nuclear Information System (INIS)

Pinnioja, S.; Autio, T.; Niemi, E.; Pensala, O.

1993-01-01

A thermoluminescence (TL) method was applied for the import control of irradiated foods. The method is based on the determination of the TL of mineral contaminants in foods. Detection of irradiation was incorporated in official Finnish control procedures in spring 1990. For foodstuffs with a reduced microbe content and in which no fumigant residues are found, possible irradiation is investigated by the TL method. The minerals are separated from the foods in different ways: picking is used for spices; water rinsing for herbs, spices, berries and mushrooms; high-density liquid to separate the organic material from the mineral fraction in seafood; and carbon tetrachloride for foods forming gels with water. To date about 140 food samples have been analysed for control purposes: 50 samples of herbs and spices, 25 samples of berries and mushrooms and 65 samples of seafood. Of these, 14 samples of herbs and spices and 5 samples of seafood were shown to have been irradiated. Differences in TL intensity between irradiated and unirradiated samples were at least 1 and usually 3-4 orders of magnitude. (orig.)

Reactor water sampling device

International Nuclear Information System (INIS)

Sakamaki, Kazuo.

1992-01-01

The present invention concerns a reactor water sampling device for sampling reactor water in an in-core monitor (neutron measuring tube) housing in a BWR type reactor. The upper end portion of a drain pipe of the reactor water sampling device is attached detachably to an in-core monitor flange. A push-up rod is inserted in the drain pipe vertically movably. A sampling vessel and a vacuum pump are connected to the lower end of the drain pipe. A vacuum pump is operated to depressurize the inside of the device and move the push-up rod upwardly. Reactor water in the in-core monitor housing flows between the drain pipe and the push-up rod and flows into the sampling vessel. With such a constitution, reactor water in the in-core monitor housing can be sampled rapidly with neither opening the lid of the reactor pressure vessel nor being in contact with air. Accordingly, operator's exposure dose can be reduced. (I.N.)

Analysis of volatile organic compounds and sensory characteristics of pork loin samples irradiated to high doses

International Nuclear Information System (INIS)

Hou Zhengchi; Sun Dakuan; Qin Zongying; Jin Jiang; Zhu Liandi; Yao Side; Sheng Kanglong

2005-01-01

Fresh pork loin samples, protein enzyme inactivated at (72 ± 3) degree C and vacuum packaged, were irradiated to up to 45 kGy at -20 degree C by 60 Co γ-rays. The irradiated samples were examined by various kinds of method to study high dose irradiation effects of sensory changes (meat color and off-odor), transverse shearing strength, weight loss in steam cooking, volatile organic compounds, and lipid oxidation. The results showed that the high dose irradiation produced no serious effects to the pork loin samples, and volunteer responses showed fine acceptability to the irradiated meat. (authors)

Device for taking gaseous samples from irradiated fuel elements

International Nuclear Information System (INIS)

Lengacker, B.

1983-01-01

The described device allows to take gaseous samples from irradiated fuel elements. It is connected with a gas analyzer and a pressure gage, so that in opening the fuel can the internal pressure can be determined

The Use of Irradiation Technology in Improving Water and Wastewater Quality

International Nuclear Information System (INIS)

Amro, H.; Tuffaha, R.; Zinati, S.; Juneidi, M.; Masaadeh, M.

2004-01-01

A study was undertaken to examine the use of irradiation technology in improving the water quality. A Cobalt- 60 gamma radiation source was used in studying the removal of trihalo methane (THM) compounds from drinking water, which forms as a result of using chlorine for water disinfection. The study also includes the use of irradiation processing for water disinfection as a substitute of water chlorination. The results show that a dose of 1000 Gy is efficient in removing 100 μg/l of THM compounds from drinking water. The same dose is also found efficient for disinfecting and controlling the microbiological content of contaminated surface water. The highly contaminated raw municipal wastewater found to require a radiation dose in the range of 1000 to 5000 Gy. (authors)

Clarification of dissolved irradiated light-water-reactor fuel

International Nuclear Information System (INIS)

Rodrigues, G.C.

1983-02-01

Bench-scale studies with actual dissolved irradiated light water reactor (LWR) fuels showed that continuous centrifugation is a practical clarification method for reprocessing. Dissolved irradiated LWR fuel was satisfactorily clarified in a bench-scale, continuous-flow bowl centrifuge. The solids separated were successfully reslurried in water. When the reslurried solids were mixed with clarified centrate, the resulting suspension behaved similar to the original dissolver solution during centrifugation. Settling rates for solids in actual irradiated fuel solutions were measured in a bottle centrifuge. The results indicate that dissolver solutions may be clarified under conditions achievable by available plant-scale centrifuge technology. The effective particle diameter of residual solids was calculated to be 0.064 microns for Oconee-1 fuel and 0.138 microns for Dresden-1 fuel. Filtration was shown unsuitable for clarification of LWR fuel solutions. Conventional filtration with filter aid would unacceptably complicate remote canyon operation and maintenance, might introduce dissolved silica from filter aids, and might irreversibly plug the filter with dissolver solids. Inertial filtration exhibited irreversible pluggage with nonradioactive stand-in suspensions under all conditions tested

A rapid supercritical fluid extraction method for the qualitative detection of 2-alkylcyclobutanones in gamma-irradiated fresh and sea water fish

International Nuclear Information System (INIS)

Tewfik, I.H.; Ismail, H.M.; Sumar, S.

1999-01-01

2-Alkylcyclobutanones are routinely used as chemical markers for irradiated foods containing lipids. However, current extraction procedures (soxhlet-Florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to GC-MS identification. A simple and rapid method for the isolation of these markers using carbon dioxide as a super critical fluid is described for low lipid content fish samples (fresh and sea water) irradiated up to 8kGy. The presence of 2-dodecylcyclobutanone (2-DCB), a radiolytic marker, was confirmed in all irradiated fish samples at all doses. This was a clear indication that the fish samples had been irradiated and that both methods of isolation (florisil and supercritical fluid extraction) were capable of qualitatively extracting this marker. Supercritical fluid extraction is proposed as an alternative extraction procedure to the florisil chromatography method currently in use and has the added advantage of a considerably shorter extraction time

KSb(OH) samples previously treated with Co y - rays irradiated with neutrons

Energy Technology Data Exchange (ETDEWEB)

Facetti, J F [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias

1969-01-01

When Ksb (OH) samples previously treated with Co y - rays or crushed are irradiated with neutrons, the yield of Sb and the annealing mechanism are apparently modified by the pretreatment. In addition it is shown that metastable species of Sb are formed under irradiation.

Effect of gamma irradiation on storability and chemical properties of different depth samples of luncheon

International Nuclear Information System (INIS)

Al-Bachir, M.; Farah, S.

2000-03-01

To investigate the effect of gamma irradiation on shelf-life of luncheon, meat packs were exposed to doses of 0, 1, 2 and 3 kGy in a 60 Co package irradiator, and the irradiated and unirradiated samples were stored at refrigeration temperature (1-3 centigrade). Microbial population and chemical changes were evaluated through storage periods (2, 4, 6 weeks) on the surface and depth in the of meat packs. The results indicated that gamma irradiation reduced the counts of microorganisms inside the samples more than the surfaces. Also the shelf-life of luncheon meat increased from two weeks for the control to 5 weeks for irradiated samples (2 and 3 kGy). Total acidity, lipid oxidation and the volatile basic nitrogen (VBN) increased during the first stage of storage up to 2 weeks of irradiation, furthermore these values were significantly higher (P> 0.05) on the surface than inside the meat packs. (author)

Decomposition of ρ-nonylphenols in water by 60Co γ-ray irradiation

International Nuclear Information System (INIS)

Kimura, Atsushi; Taguchi, Mitsumasa; Kojima, Takuji; Namba, Hideki

2005-01-01

ρ-Nonylphenols (NPs), one of endocrine disrupting chemicals, are used as plastic flexibilizers or nonionic surfactants, and widely released into the water environment. Hydroxyl radicals produced from water molecules by γ-ray irradiation have high oxidation reactivity. Recently, treatments with the hydroxyl radicals have drawn much attention to conserve the water environment. In this study, decompositions of NPs in water were investigated using hydroxyl radicals by 60 Co γ-rays irradiation. The concentrations of the NPs at initial concentration from 45 to 1000 nM were decomposed by γ-ray irradiation. Qualitative and quantitative analyses of NPs were carried out by high performance liquid chromatography. The decomposition curves of NPs at each initial concentration were analyzed as single exponential functions. Alkylphenol activity of aqueous NPs solution, which was estimated by enzyme-linked immunosorbent assay, implies the irradiation products have alkylphenol activity. Two products having molecular weight of 236 were investigated by liquid chromatography-mass spectrometry, and were considered to be ρ-nonylcatechol and 1-(ρ-hydroxyphenyl)-1-nonanol on the basis of the oxidation mechanisms of ρ-cresol and 4-ethylphenol. (author)

Impact of gamma-irradiation on some mass transfer driven operations in food processing

Energy Technology Data Exchange (ETDEWEB)

Rastogi, N.K. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India)]. E-mail: nkrastogi@cftri.com

2005-08-01

The effect of gamma-irradiation pretreatment on some mass transfer driven operations such as dehydration, osmotic dehydration and rehydration, commonly used in food processing, was studied. Applied irradiation up to 12.0 kGy resulted in decrease in hardness of the samples, as indicated by texture analysis. The effective diffusion coefficients of water and solute determined for dehydration, osmotic dehydration as well as for rehydration using a Fickian diffusion model. The effective diffusion coefficients for water (in case of osmotic dehydration and dehydration) and solid diffusion (in case of osmotic dehydration) were found to increase exponentially with doses of gamma-irradiation (G) according to an equation of the form D=A exp(-B/G), where A and B are constants. Microstructures of irradiated-carrot samples revealed that the exposure of carrot to gamma irradiation resulted in the breakage of cell wall structure, thereby causing softening of irradiated samples and facilitating mass transfer during dehydration and osmotic dehydration. The rehydration characteristics showed that gamma-irradiated sample did not absorb as much water as control, probably due to loss of cell integrity.

Impact of gamma-irradiation on some mass transfer driven operations in food processing

International Nuclear Information System (INIS)

Rastogi, N.K.

2005-01-01

The effect of gamma-irradiation pretreatment on some mass transfer driven operations such as dehydration, osmotic dehydration and rehydration, commonly used in food processing, was studied. Applied irradiation up to 12.0 kGy resulted in decrease in hardness of the samples, as indicated by texture analysis. The effective diffusion coefficients of water and solute determined for dehydration, osmotic dehydration as well as for rehydration using a Fickian diffusion model. The effective diffusion coefficients for water (in case of osmotic dehydration and dehydration) and solid diffusion (in case of osmotic dehydration) were found to increase exponentially with doses of gamma-irradiation (G) according to an equation of the form D=A exp(-B/G), where A and B are constants. Microstructures of irradiated-carrot samples revealed that the exposure of carrot to gamma irradiation resulted in the breakage of cell wall structure, thereby causing softening of irradiated samples and facilitating mass transfer during dehydration and osmotic dehydration. The rehydration characteristics showed that gamma-irradiated sample did not absorb as much water as control, probably due to loss of cell integrity

Evidence of 2,7/2,8-dibenzodichloro-p-dioxin as a photodegradation product of triclosan in water and wastewater samples

International Nuclear Information System (INIS)

Mezcua, Milagros; Gomez, M. Jose; Ferrer, Imma; Aguera, Ana; Hernando, M. Dolores; Fernandez-Alba, Amadeo R.

2004-01-01

A photodegradation study of triclosan, a commonly used antimicrobial agent, was carried out in order to investigate the formation of dibenzodichlorodioxin as a by-product of photodegradation in various environmental matrices and under different conditions. Deionized water and wastewater samples, spiked at 8 μg/mL with triclosan, were irradiated with natural sunlight. Aliquots of the spiked water samples were taken at different times of irradiation and compounds were isolated from the water samples by solid-phase extraction. Separation and detection of the compounds and degradation products was accomplished by gas chromatography-mass spectrometry. A major photolysis degradation product of triclosan, 2,7/2,8-dibenzodichloro-p-dioxin, was identified in wastewater samples. The photolysis experiment showed the simultaneous disappearance of triclosan and the appearance of the dioxin dependent on the pH and the organic matter content. Furthermore, a pilot survey monitoring for influent and effluent waters from a wastewater treatment plant was carried out. The presence of triclosan in all wastewater samples analyzed was revealed and dioxin was found in 80% of the cases, in influents and effluents, thus indicating its input and persistence through the wastewater treatment process. This represents a major finding since dioxins are more toxic than triclosan. Moreover, the presence of such compounds in wastewaters revealed the immediate need to improve the ''classical'' water treatment techniques, as well as considering limitation in water re-use

Developing Water Sampling Standards

Science.gov (United States)

Environmental Science and Technology, 1974

1974-01-01

Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

Influence of audiovisuals and food samples on consumer acceptance of food irradiation

International Nuclear Information System (INIS)

Pohlman, A.J.; Wood, O.B.; Mason, A.C.

1994-01-01

The effects of audiovisual presentation on consumers' knowledge and attitudes toward food irradiation were demonstrated. Food irradiation is a method of food preservation that can destroy the microorganisms responsible for many foodborne illnesses and food spoilage. However, the food industry has been slow to adopt this method because it is unsure of consumer acceptance. One hundred and seventy-nine consumers were given a slide-tape presentation on food irradiation. Test subjects were also presented with a sample of irradiated strawberries. It was found that participants knew more about and were more positive toward food irradiation following the educational program. These findings demonstrate the value of educational materials in influencing the food preferences of consumers

Determination of photoformation rates and scavenging rate constants of hydroxyl radicals in natural waters using an automatic light irradiation and injection system

International Nuclear Information System (INIS)

Nakatani, Nobutake; Hashimoto, Norichika; Shindo, Hirotaka; Yamamoto, Masatoshi; Kikkawa, Megumi; Sakugawa, Hiroshi

2007-01-01

Photoformation rates and scavenging rate constants of hydroxyl radicals (·OH) in natural water samples were determined by an automatic determination system. After addition of benzene as a chemical probe to a water sample in a reaction cell, light irradiation and injection of irradiated water samples into an HPLC as a function of time were performed automatically. Phenol produced by the reaction between ·OH and the benzene added to the water sample was determined to quantify the ·OH formation rate. The rate constants of ·OH formation from the photolysis of nitrate ions, nitrite ions and hydrogen peroxide were comparable with those obtained in previous studies. The percent of expected ·OH photoformation rate from added nitrate ion were high in drinking water (97.4%) and river water (99.3%). On the other hand, the low percent (65.0%) was observed in seawater due to the reaction of ·OH with the high concentrations of chloride and bromide ions. For the automatic system, the coefficient of variance for the determination of the ·OH formation rate was less than 5.0%, which is smaller than that in the previous report. When the complete time sequence of analytical cycle was 40 min for one sample, the detection limit of the photoformation rate and the sample throughput were 8 x 10 -13 M s -1 and 20 samples per day, respectively. The automatic system successfully determined the photoformation rates and scavenging rate constants of ·OH in commercial drinking water and the major source and sink of ·OH were identified as nitrate and bicarbonate ions, respectively

Microbial inactivation and cytotoxicity evaluation of UV irradiated coconut water in a novel continuous flow spiral reactor.

Science.gov (United States)

Bhullar, Manreet Singh; Patras, Ankit; Kilanzo-Nthenge, Agnes; Pokharel, Bharat; Yannam, Sudheer Kumar; Rakariyatham, Kanyasiri; Pan, Che; Xiao, Hang; Sasges, Michael

2018-01-01

A continuous-flow UV reactor operating at 254nm wave-length was used to investigate inactivation of microorganisms including bacteriophage in coconut water, a highly opaque liquid food. UV-C inactivation kinetics of two surrogate viruses (MS2, T1UV) and three bacteria (E. coli ATCC 25922, Salmonella Typhimurium ATCC 13311, Listeria monocytogenes ATCC 19115) in buffer and coconut water were investigated (D 10 values ranging from 2.82 to 4.54mJ·cm -2 ). A series of known UV-C doses were delivered to the samples. Inactivation levels of all organisms were linearly proportional to UV-C dose (r 2 >0.97). At the highest dose of 30mJ·cm -2 , the three pathogenic organisms were inactivated by >5 log 10 (pUV-C irradiation effectively inactivated bacteriophage and pathogenic microbes in coconut water. The inactivation kinetics of microorganisms were best described by log linear model with a low root mean square error (RMSE) and high coefficient of determination (r 2 >0.97). Models for predicting log reduction as a function of UV-C irradiation dose were found to be significant (pUV-C treatment did not generate cytotoxic compounds in the coconut water. This study clearly demonstrated that high levels of inactivation of pathogens can be achieved in coconut water, and suggested potential method for UV-C treatment of other liquid foods. This research paper provides scientific evidence of the potential benefits of UV-C irradiation in inactivating bacterial and viral surrogates at commercially relevant doses of 0-120mJ·cm -2 . The irradiated coconut water showed no cytotoxic effects on normal intestinal and healthy mice liver cells. UV-C irradiation is an attractive food preservation technology and offers opportunities for horticultural and food processing industries to meet the growing demand from consumers for healthier and safe food products. This study would provide technical support for commercialization of UV-C treatment of beverages. Copyright © 2017 Elsevier Ltd. All

Combined effect of water activity, radiation dose, and temperature during irradiation on the survival of three Salmonella serotypes

International Nuclear Information System (INIS)

Moussa, A.E.

1977-01-01

Stationary-phase cells of S. typhimurium, S. thompson and S. senftenberg were irradiated at room temperature with 10 MeV electrons, either in water or in glucose, glyzerine, NaCl, CaCl 2 , or LiCl solutions of different concentrations. Furhter experimental parameters, i.e. the temperatures O 0 C and 50 0 C, were investigated in samples whose water activity had been adjusted to certain asub(W) values. Using the sorption isotherm method, different water activities were obtained in egg powder at temperatures of 5 0 C, 25 0 C, and 45 0 C. In all experiments, the survival of Salmonellae was investigated by determining the number of surface germs. In saccharose, glucose, glyzerine, and NaCl, the radioresistance of Salmonellae increases with decreasing water activity. There is a linear relation at different temperatures between D 10 values and asub(W) values in saccharose and glucose. In glyzerine solutions, the D 10 values show a steep rise with decreasing asub(W) = 1.0 and 0.9 and a less steep rise below 0.9. Below asub(W) = 0.5, they do not change any further. At asub(W) values below 0,90, CaCl 2 and LiCl show a strong cytotoxic effect, independent of irradiation. The higher the temperature on irradiation, the lower will be the radioresistance of Salmonellae. Irradiation at a temperature of 50 0 C showed a synergistic effect. The radioresistance of Salmonellae in egg powder increased with decreasing asub(W) value of the egg powder. When egg powder was irradiated at 45 0 C, there was a strong synergistic effect which is important for practical applications of irradiation in egg powder sterilisation. The radioresistance of Salmonellae in egg powder was independent of the serotype. (orig./MG) [de

Ionizing radiation effect on teas of Camellia sinensis plant irradiated with different water activities

International Nuclear Information System (INIS)

Fanaro, Gustavo Bernardes

2013-01-01

Tea is the most consumed beverage in the world. Teas from Camellia sinensis plant have high levels of antioxidants, which mean that they may have several beneficial effects on health preservation. For centuries, mankind looks for ways to conserve better and for a longer time the food that they eat. The food irradiation process is a largely technique used worldwide, and is recommended by many health agencies and authorities of several countries. The radiation interacts with the material causing two kinds of effects, the direct and the indirect effect. In the direct effect the radiation interacts with the DNA molecule, breaking it, and then inactivates the cell. In the indirect effect, which represents 70% of the interaction, the radiation breaks the water molecule in a process denominated radiolysis, creating a number of free radicals that will interact with the cellular components, leading to the cell death. Therefore, the aim of this work is to study the effects of gamma radiation on two kinds of tea from Camellia sinensis plant irradiated with different water activities. The green tea and black tea samples had their Aw adjusted to three values (high Aw, medium Aw, and low Aw). The samples were irradiated in 60 Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The analyses used were: microbiology by plate count, total phenolic compounds quantification, antioxidant activity by ORAC assay, and identification and quantification of main antioxidants in these beverages. It was noted that the greater the quantity of free water present in the medium, the lower was the dose to achieve microbiological control. The green tea showed to be a little more susceptible to irradiation by high Aw once there was more variation in the amount of flavonoids and phenolics than the black tea, decreasing the amount of these compounds in some doses, but increasing the amount in other ones. However in both teas, these changes can be considered insignificant, since there

Irradiation of lithium aluminate and tritium extraction

International Nuclear Information System (INIS)

Roth, E.; Abassin, J.J.; Botter, F.; Briec, M.; Chenebault, P.; Masson, M.; Rasneur, B.; Roux, N.

1984-12-01

After preselection of the preparation procedures, following short irradiations, γ LiAl0 2 samples submitted to 2.10 19 fast neutrons cm -2 and 1.5 10 20 thermal neutrons cm -2 fluences experienced no apparent damage. Post-irradiation tritium extraction from samples irradiated to 2.10 17 neutrons/cm 2 in quartz ampoules produced mostly tritiated water. When in-pile experiments are performed the sample container material influences greatly the measured ratio of tritium gas to tritiated water - Stainless steel capsules yield more T 2 gas than quartz capsules probably because of a reduction process. Difficulties in interpretation arise from adsoption of tritiated water on the measuring lines. Both experiments showed that much faster extraction rates are obtained from small grain size samples than from large ones at the same open porosity. If diffusion in the grains controls the extraction rates, apparent D values vary from 10 -16 to 1.5 10 -15 cm 2 S -1 in the temperature range explored. Around 500 0 C small grain samples reached equilibrium tritium concentration of a few mCi in 4 hours. Such values are suitable for a blanket concept

Study on the sterilization of canned water melon by gamma irradiation

International Nuclear Information System (INIS)

Kim, B.M.

1978-01-01

In order to study the effects of gamma-irradiations on the storage life of canned water melon, the contents of canning water melon were controlled pH to 4.0 and 5.0 by adding some kinds of organic acids such as citric acid, tartaric acid, and ascorbic acid, respectively. The pH controlled water melons were canned, followed by being exposed to 0.25, 0.5, and 1.0 Mrads of gamma-ray, respectively. The results were as follows: In non-acid canned water melon, the higher doses of radiation induced the more efficiency on the extension of storage life of it even if the efficiency was mot so great. By irradiations of 1.0 Mrads, it could be kept for 15 days without any deterioration. By means of the addition of organic acids, the radiation effect on the extension of the storage life of the above food increased remarkably. In particular, the water melon cans with ascorbic acid (pH 4.0) could be kept for 60 days without any deterioration by gamma-irradiation of 0.5 and 1.0 Mrads. (Author)

Emulation of neutron irradiation effects with protons: validation of principle

International Nuclear Information System (INIS)

Was, G.S.; Busby, J.T.; Allen, T.; Kenik, E.A.; Jensson, A.; Bruemmer, S.M.; Gan, J.; Edwards, A.D.; Scott, P.M.; Andreson, P.L.

2002-01-01

This paper presents the results of the irradiation, characterization and irradiation assisted stress corrosion cracking (IASCC) behavior of proton- and neutron-irradiated samples of 304SS and 316SS from the same heats. The objective of the study was to determine whether proton irradiation does indeed emulate the full range of effects of in-reactor neutron irradiation: radiation-induced segregation (RIS), irradiated microstructure, radiation hardening and IASCC susceptibility. The work focused on commercial heats of 304 stainless steel (heat B) and 316 stainless steel (heat P). Irradiation with protons was conducted at 360 deg. C to doses between 0.3 and 5.0 dpa to approximate those by neutron irradiation at 275 deg. C over the same dose range. Characterization consisted of grain boundary microchemistry, dislocation loop microstructure, hardness as well as stress corrosion cracking (SCC) susceptibility of both un-irradiated and irradiated samples in oxygenated and de-oxygenated water environments at 288 deg. C. Overall, microchemistry, microstructure, hardening and SCC behavior of proton- and neutron-irradiated samples were in excellent agreement. RIS analysis showed that in both heats and for both irradiating particles, the pre-existing grain boundary Cr enrichment transformed into a 'W' shaped profile at 1.0 dpa and then into a 'V' shaped profile between 3.0 and 5.0 dpa. Grain boundary segregation of Cr, Ni, Si, and Mo all followed the same trends and agreed well in magnitude. The microstructure of both proton- and neutron-irradiated samples was dominated by small, faulted dislocation loops. Loop size distributions were nearly identical in both heats over a range of doses. Saturated loop size following neutron irradiation was about 30% larger than that following proton irradiation. Loop density increased with dose through 5.0 dpa for both particle irradiations and was a factor of 3 greater in neutron-irradiated samples vs. proton-irradiated samples. Grain boundary

Hydrogen radiolytic release from zeolite 4A/water systems under γ irradiations

International Nuclear Information System (INIS)

Frances, Laëtitia; Grivet, Manuel; Renault, Jean-Philippe; Groetz, Jean-Emmanuel; Ducret, Didier

2015-01-01

Although the radiolysis of bulk water is well known, some questions remain in the case of adsorbed or confined water, especially in the case of zeolites 4A, which are used to store tritiated water. An enhancement of the production of hydrogen is described in the literature for higher porous structures, but the phenomenon stays unexplained. We have studied the radiolysis of zeolites 4A containing different quantities of water under 137 Cs gamma radiation. We focused on the influence of the water loading ratio. The enhancement of hydrogen production compared with bulk water radiolysis has been attributed to the energy transfer from the zeolite to the water, and to the influence of the water structure organization in the zeolite. Both were observed separately, with a maximum efficiency for energy transfer at a loading ratio of about 13%, and a maximum impact of structuration of water at a loading ratio of about 4%. - Highlights: • We irradiated samples of zeolites 4A which contained different quantities of water. • We measured the quantity of hydrogen released. • Hydrogen radiolytic yields, present two maxima, for two water loading ratios. • Hydrogen release is enhanced by the strength of the zeolite/water interaction. • Hydrogen release is enhanced by the quantity of water interacting with the zeolite

Preliminary studies on the use of irradiation for decontaminating water and sludge in wastewater treatment plants in Chile

International Nuclear Information System (INIS)

Villanueva, Loreto; Schrader, Rosemarie

1999-01-01

This work describes the activities carried out to date by the Chilean Nuclear Energy Commission, CCHEN, in prospecting the application of gamma and electron beam irradiation to the decontamination of sewage water and sludge in the country. Sludge, in particular, will become a relevant environmental problem in the coming years, because of the large amounts that will be generated, due to the construction of many wastewater treatment plants in the country. The main study consisted of experimental gamma irradiation tests on representative samples of digested sludge from two pilot wastewater treatment plants operating in Santiago. This study showed the technical feasibility of using low irradiation doses, of around 2-3 kGy to significantly reduce the pathogen content in this sludge. Preliminary tests were also carried out to determine that the disinfected sludge was fit for agricultural use due to its nutrient content. A preliminary technical and economic evaluation is being prepared on the use of gamma irradiation for sludge disinfection, as a complement to the experimental studies. With this evaluation a feasible process has been outlined for using gamma irradiation in conjunction with conventional processes for the sludge disinfection or hygienization in domestic wastewater treatment plants, in order to produce a useful material for agricultural use that meets the demanding EPA standards when classified as class A sludge, which permits agricultural use without sanitary restrictions. Several evaluations have been made to determine the potential use of irradiation for water and industrial wastewater effluents decontamination, considering normative standards as well as technical and economic aspects. One of these has been the preliminary evaluation of using electron beam irradiation for disinfecting drinking water, which has the technical advantage of preventing the formation of trihalomethanes, that occur in water chlorination due to the presence of natural humic

Ultraviolet irradiation of water - an alternative to chlorination

International Nuclear Information System (INIS)

Andvik, N.-O.

1977-01-01

The advantages of ultraviolet radiation of wavelength 2500-2600 Aangstroem are discussed and the principal considerations to be taken into account in the planning of an irradiation plant are presented. The design of a typical irradiation anit is illustrated and described briefly. Such plants were first used in Switzerland and are widely used there and in Austria. In the course of the past two years several plants have been installed in Norway. They are suitable both for treatment of drinking water and pretreated sewage, but less satisfactory for swimming pools. (JIW)

Use of SCGE method for detection of DNA comet in irradiated samples of poultry and shrimp

International Nuclear Information System (INIS)

Rajaei, R.; Hosseini, S.L.

2005-01-01

DNA in food may sustain damage by gamma irradiation.This damage can be detected by a sensitive technique, called single cell gel electrophoresis. This is a simple and low-cost technique for rapid screening of the cells of irradiated foodstuffs. For this purpose, poultry and shrimp samples were irradiated by the 60 Co gamma radiation. The radiation doses for poultry were 2,5 and 7 kGy and for shrimp were 3 and 7kGy, respectively. The irradiation samples were compared with those of unirradiated types (control). In addition, the effects of shelf-life and temperature were considered on the poultry samples only. We have found that this technique is easily applicable for identification of irradiated from unirradiated samples and it is found to be irrespective of the applied dose. It is worth mentioning that any DNA change arising from any source, for example temperature fluctuation, may be detected by the single cell gel electrophoresis technique

Dose response of artificial irradiation of fluvial sediment sample for ESR dating

International Nuclear Information System (INIS)

Liu Chunru; Yin Gongming; Gao Lu; Li Jianping; Han Fei; Lin Min

2011-01-01

ESR dating samples need be irradiated to obtain dose response curve and the equivalent dose. The artificial dose rate is about 1 x 10 -1 -1 x 10 2 Gy/min, whereas the natural dose rate is about 3 Gy/ka. Therefore, one must be sure whether the much higher artificial dose rate is suitable for the ESR dating study. In this paper, we use different artificial dose rate to irradiate the same fluvial sample and measure the quartz Al centre ESR signal under the same conditions. The dose response curves are compared, in an attempt to gain a preliminary knowledge on that problem and build a good foundation for our ESR dating studies on fluvial samples. (authors)

Effects on storage life and quality of irradiated mangoes

International Nuclear Information System (INIS)

Pongsuwan, Dara; Therapawa, Wallapa; Akawassapong, Pakinee; Jattanajet, Jumlong.

1982-01-01

Investigations on the effect of irradiation at 50 Krad, hot water treatment at 55 degC 5 min and hot water treatment followed by irradiation were carried out on the mature green Keaw mango to eradicate anthracnose disease development and delay ripening. Before introducing all treatments, mangoes were inoculated by Colletotrichum gloeosporioides. All samples were determined after stored at 10 +- 2 degC and at 85% RH for 3 weeks. No difference in disease control between untreated and irradiated batches, but fruits treated with hot water followed by irradiation were significantly different from untreated ones. All treatments were effective in delaying ripening. Higher dosage of irradiation with a combination of hot water treatment was studied on colour break Pimsen Prure mango and 75 Krad after hot water treatment proved to be promising. Further study is being conducted

The effect of γ-ray irradiation on the water immersion and electricity application deterioration of polyethylene

International Nuclear Information System (INIS)

Higashimura, Yutaka; Fujioka, Norihide; Karino, Yasushi; Onuki, Tsutomu; Watanabe, Kiyoshi.

1984-01-01

Two types of polyethylene, that is, standard low density cross-linked polyethylene (XLPE-A) and the same with the addition of a polymer having ester radicals (XLPE-B), were used for this experiment. The water immersion and electricity application test was carried out 1) simultaneously with γ-ray irradiation, 2) after γ-ray irradiation, and 3) without γ-ray irradiation. It was found that 1) the water-immersion and electricity-application life of XLPE-A was rather elongated by γ-ray irradiation, 2) the water-immersion and electricity-application life of XLPE-B was shortened by γ-ray irradiation, which is probably attributable to the bond-rupture of ester radicals of the added polymer, 3) the life, when the irradiation of γ-ray and the application of electricity in water were simultaneously exerted, agreed well with the empirical equation which is derived on the assumption that the life is decreased proportionally to the overall dose of γ-ray, and 4) even when polyethylene was irradiated with γ-ray in hot water, the properties of polyethylene was estimated to deteriorate in the same extent as in the air. (Yoshitake, I.)

Irradiation of spices and herbs

International Nuclear Information System (INIS)

Eiss, M.I.

1983-01-01

Gamma irradiation has been extensively studied as a means of reducing the microbial contamination of spices. Experiments indicate that spices, with water contents of 4.5-12%, are very resistant to physical or chemical change when irradiated. Since spices are used primarily as food flavoring agents, their flavor integrity must not be changed by the process. Sensory and food applications analysis indicate no significant difference between irradiated samples and controls for all spices tested

Identification of irradiated foods prospects for post-irradiation estimate of irradiation dose in irradiated dry egg products

International Nuclear Information System (INIS)

Katusin-Raxem, B.; Mihaljievic, B.; Razem, D.

2002-01-01

Radiation-induced chemical changes in foods are generally very small at the usual processing doses. Some exception is radiation degradation of lipids, which are the components most susceptible to oxidation. A possible use of lipid hydroperoxides (LOOH) as indicators of irradiation is described for whole egg and egg yolk powders. A sensitive and reproducible spectrophotometric method for LOOH measurement based on feric thiocyanate, as modified in our laboratory, was applied. This method enabled the determination of LOOH, including oleic acid hydroperoxides, which is usually not possible with some other frequently used methods. The lowest limit of 0.05 mmol LOOH/kg lipid could be measured. The measurements were performed in various batches of whole egg and egg yolk powders by the same producer, as well as in samples supplied by various producers. Baseline level in unirradiated egg powder 0.110 ± 0.067 mmol LOOH /kgL was established. The formation of LOOH with dose, as well as the influence of age, irradiation conditions, storage time and storage conditions on LOOH were investigated. The irradiation of whole egg and egg yolk powders in the presence of air revealed an initially slow increase of LOOH, caused by an inherent antioxidative capacity, followed by a fast linear increase after the inhibition dose (D o ). In all investigated samples D o of 2 kGy was determined. Hydroperoxides produced in irradiated materials decay with time. In whole egg and egg yolk powders, after an initially fast decay, the level of LOOH continued to decrease by the first-order decay. Nevertheless, after a six months storage it was still possible to unambiguously identify samples which had been irradiated with 2 kGy in the presence of air. Reirradiation of these samples revealed a significant reduction of D o to 1 kGy. In samples irradiated with 4 kGy and kept under the same conditions, the shortening of D o to 0.5 kGy was determined by reirradiation. This offers a possibility for the

Preparation and characterisation of irradiated crab chitosan and New Zealand Arrow squid pen chitosan

International Nuclear Information System (INIS)

Shavandi, Amin; Bekhit, Adnan A.; Bekhit, Alaa El-Din A.; Sun, Zhifa; Ali, M. Azam

2015-01-01

The properties of chitosan from Arrow squid (Nototodarus sloanii) pen (CHS) and commercial crab shell (CHC) were investigated using FTIR, DSC, SEM and XRD before and after irradiation at the dose of 28 kGy in the presence or absence of 5% water. Also, the viscosity, deacetylation degree, water and oil holding capacities, colour and antimicrobial activities of the chitosan samples were determined. Irradiation decreased (P < 0.05) the viscosity of CHC from 0.21 to 0.03 Pa s and of CHS from 1.71 to 0.23 Pa s. The inclusion of water had no effect on the viscosity of irradiated chitosan. Irradiation did not affect the degree of deacetylation of CHC, but increased the deacetylation degree of CHS from 72.78 to 82.29% in samples with 5% water. Water and oil holding capacities of CHS (1197.30% and 873.3%, respectively) were higher (P < 0.05) than those found in CHC (340.70% and 264.40%, respectively). The water and oil holding capacities were decreased for both types of chitosan irradiation, but were not affected by the addition of water. Squid pen chitosan was whiter in colour (White Index = 90.06%) compared to CHC (White Index = 83.70%). Generally, the CHC samples (control and irradiated) exhibited better antibacterial activity compared to CHS, but the opposite was observed with antifungal activity. - Highlights: • Chitosan prepared from Arrow squid pens (Nototodarus sloanii). • Chitosan samples were gamma irradiated at 28 kGy. • Squid pen chitosan showed high fat and water uptake capacities compared to crab shell chitosan. • Gamma irradiation enhanced the DDA of squid pen chitosan but not crab shell chitosan.

Femtosecond laser irradiation of the fluorescent molecules-loaded poly(lactic-co-glycolic acid)

Science.gov (United States)

Umemoto, Taiga; Shibata, Akimichi; Terakawa, Mitsuhiro

2017-09-01

Molecular release from scaffolds is desired for tailoring cell-compatible tissue engineering. Several methods have been proposed to control molecular release, such as annealing, plasma treatment, and laser processing. In this study, we describe the alteration of Rhodamine B (RhB)-loaded poly(lactic-co-glycolic acid) (PLGA) after femtosecond laser irradiation, which was evaluated on the basis of the water absorption and mass remaining. Fluorescence measurement of released RhB molecules revealed the acceleration of the molecular release upon 400-nm laser irradiation, whereas 800-nm laser irradiation did not induce a comparable degree of change compared with non-irradiated samples. The result of the water absorption measurement indicates that the large amount of water absorption of 400-nm laser-irradiated PLGA sample may accelerate the diffusion of the loaded molecules through absorbing water, which resulted in the faster molecular release.

Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

2016-10-01

Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of ~200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

Science.gov (United States)

Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka; Toshito, Toshiyuki

2016-10-01

Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of 200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

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

International Nuclear Information System (INIS)

Manalo, J.A.

1985-09-01

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

Thermal analysis of the APT materials irradiation samples

International Nuclear Information System (INIS)

Maloy, S.A.; Willcutt, G.J.; James, M.R.; Teague, J.; Diebe, D.A.; Sommer, W.F.; Ferguson, P.D.

1998-01-01

The accelerator production of tritium (APT) project proposes to use a 1.7 GeV, 100 mA proton beam to produce neutrons from an Inconel 718 clad tungsten target. The neutrons are multiplied and moderated in a lead/water blanket before being captured in He 3 to form tritium. In this process, the materials in the target and blanket region are exposed to a wide range of different fluxes comprised of protons and neutrons with energies into the GeV range. To investigate the effect of irradiation on the mechanical properties of candidate APT materials (Inconel 718, 316L stainless steel, Al 6061-T6, Mod 9Cr-1Mo, 304L stainless steel and Al5052-0), the APT Engineering Design and Development group fielded an extensive materials irradiation using the LANSCE (Los Alamos Neutron Science Center) accelerator, which operates at an energy of 800 MeV and a current of 1 mA. The test set-up was designed to place mechanical test specimens in locations in and near the proton beam where the environment of proton and neutron fluxes and temperatures are prototypic to those expected in the APT target/blanket (50--170 C). After irradiating for about 3,600 hours, the maximum achieved proton fluence was 4--5 x 10 21 p/cm 2 for the materials in the center of the beam. To obtain relevant data on the change in the mechanical properties with fluence, it is essential to know the temperature at which the materials were irradiated. This paper explains the method of determining the specimen temperature and reports some specific examples

Physicochemical properties of brown rice as influenced by gamma irradiation, variety and storage

International Nuclear Information System (INIS)

Sabularse, V.C.

1988-01-01

Effects of gamma irradiation, variety and storage on physicochemical properties of brown rice from three Louisiana rice varieties: Mars, a medium grain variety, Lemont and Tebonnet, long grain varieties, were determined. Cooking time was significantly reduced in Mars and Lemont at doses of 200 and 300 Krads. Irradiation increased cooking rate, water uptake at 80 degree C, water uptake ratios, total solids content in residual cooking liquid and starch damage from 100 to 300 Krad samples. Water uptake at 96 degree C generally decreased with increasing dose levels. Evidence indicated alterations in the rice grain structures and composition. The component drastically affected by gamma irradiation was starch as shown by reduced cooking time, increased water uptake, increased amounts of starch and protein in residual cooking liquid, reduced volume expansion, increased damage starch and changes in amylographic pasting characteristics. Scanning electron microscopy showed more simple starch granules in irradiated samples than in nonirradiated samples. Structural changes in the bran layer due to gamma irradiation were not evident from electron micrographs

Water accelerated transformation of d-limonene induced by ultraviolet irradiation and air exposure.

Science.gov (United States)

Li, Li Jun; Hong, Peng; Jiang, Ze Dong; Yang, Yuan Fan; Du, Xi Ping; Sun, Hao; Wu, Li Ming; Ni, Hui; Chen, Feng

2018-01-15

d-Limonene is a fragrant chemical that widely exists in aromatic products. Isotopic labelling of water molecules plus GC-MS and GC-PCI-Q-TOF analyses were used to investigate the influence of water molecules on chemical transformation of d-limonene induced by UV irradiation and air exposure. The results showed that the synergistic effect of UV irradiation, air exposure and water presence could facilitate d-limonene transformation into the limonene oxides: p-mentha-2,8-dienols, hydroperoxides, carveols, l-carvone and carvone oxide. UV irradiation, air exposure, or water alone, however, caused negligible d-limonene transformation. With the aid of isotopic labelling of water and oxygen molecules, it was found that water molecules were split into hydrogen radicals and hydroxyl radicals, and the hydrogen radicals, in particular, promoted the transformation reactions. This study has elucidated the mechanism and factors that influence the transformation of d-limonene, which will benefit industries involved in production and storage of d-limonene-containing products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and characterization of irradiated injectable bone substitute paste based on hydroxyapatite

International Nuclear Information System (INIS)

Yessy Warastuti; Basril Abbas

2011-01-01

Synthesis and characterization of hydroxyapatite, chitosan and hydroxypropyl methylcellulose (HPMC) composite in injectable paste form have been done. The composite was synthesized by stirring hydroxyapatite, chitosan and HPMC until homogen. IBS paste was irradiated at the dose of 25 kGy (sterile dose). Characterization of IBS paste was conducted by measuring of the water content, identification of functional group with Fourier Transform Infra Red Spectrophotometer (FTIR), and identification of sample morphology with Scanning Electron Microscope Energy Dispersive Spectrophotometer (SEM EDS). The result showed that the water content of irradiated sample was higher than unirradiated sample due to water radiolysis. Several specific bands of IBS paste were identified, i.e., carbonate (CO 3 2- ), at 1420 cm -1 , phosphate (PO 4 3- ) at 1043 cm -1 , 605 cm -1 , 568 cm -1 and chitosan (NH 2 ) at 1599 cm -1 . There is no significant difference in absorbed band between irradiated and unirradiated samples. IBS paste has a microstructure with the size of 0.05 – 0.1 μm. Electron beam irradiation did not change the structure and morphology of sample. (author)

ESR low-temperature investigations on water-containing biological substances to determine type, concentration and kinetics of the free radicals induced by irradiation with X-rays and β-radiation

International Nuclear Information System (INIS)

Fell, H.A.

1975-01-01

In the present work, ESR investigations on pure water and further biological interesting substances with high water content were carried out. In order to stabilize the free primary radicals occurring after irradiation, it was necessary to cool down the samples to the temperature of liquid helium. Methods were developed which enabled irradiation of the pure sample substance at this temperature to be performed. Two different kinds of radiation were applied, X-ray and β-radiation, and the results were compared with one another. The problem of transporting the irradiated sample from the place of irradiation to the measuring position maintaining 4.2 K was solved. A device was constructed to study the radical kinetics with whose assistance the samples can be brought to a pre-chosen temperature for a certain time. A calibration of the ESR spectrometer as well as the use of a secondary standard was necessary for the quantitative determination of the radical concentration. The type and concentration of the primary radicals occurring were investigated in the measured samples as well as the reduction of the radical concentration with increasing temperature determined. The measured values were compared with theoretical considerations. The effect of the radicals on biological systems at various temperatures was discussed. (orig./LH) [de

Experimental fuel channel for samples irradiation at the RB reactor

International Nuclear Information System (INIS)

Pesic, M.; Markovic, H.; Sokcic-Kostic, M.; Miric, I.; Prokic, M.; Strugar, P.

1984-12-01

An 80% enriched UO 2 fuel channel at the RB nuclear reactor in the 'Boris Kidric' Institute of Nuclear Sciences is modified for samples irradiation by fast neutrons. Maximum sample diameter is 25 mm and length up to 1000 mm. Characteristics of neutron and gamma radiation fields of this new experimental channel are investigated. In the centre of the channel, the main contribution to the total neutron absorbed dose, i.e. 0.29 Gy/Wh of reactor operation, is due to the fast neutron spectrum component. Only 0.05 Gy and 0.07 Gy in the total neutron absorbed dose are due to intermediate and thermal neutrons, respectively. At the same time the gamma absorbed dose is 0.35 Gy. The developed experimental fuel channel, EFC, has wide possibilities for utilization, from fast neutron spectrum studies, electronic component irradiations, dosemeters testing, up to cross-section measurements. (author)

Safety report for the independent CO2 loop for cooling the samples irradiated in the vertical experimental channels of the RA reactor

International Nuclear Information System (INIS)

Pavlovic, A.; Zivkovic, S.; Milosevic, M.; Strugar, P.

1969-01-01

Independent CO 2 loop was designed for cooling the samples irradiated in the vertical experimental channels in the region of heavy water or in the graphite reflector. It is considered as a significant improvement of the RA reactor experimental possibilities. Six 'heads' are placed in vertical experimental channels and connected in parallel with the outer loop which contains out-of-reactor equipment. It is planned to irradiate samples in the 'heads' of the loop for the needs of Hot laboratory and Laboratory for reactor materials. Heat generated during sample irradiation is removed by CO 2 circulation. This report contains detailed description of the main loop, auxiliary systems, calculation results of anti reactivity and activation of construction materials of the low-temperature CO 2 loop. A separate chapter is devoted to control and regulation of temperature and pressure. Testing of the fundamental parameters of the coolant loop showed that it could fulfill more demanding tasks than designed by the project. Annex of this report includes results of leak testing for the loop 'heads' in vertical experimental channels VEK-6 and VEK-8 by helium leak detector [sr

Inhalation radiotoxicity of irradiated thorium as a heavy water reactor fuel

International Nuclear Information System (INIS)

Edwards, G.W.R.; Priest, N.D.; Richardson, R.B.

2013-01-01

The online refueling capability of Heavy Water Reactors (HWRs), and their good neutron economy, allows a relatively high amount of neutron absorption in breeding materials to occur during normal fuel irradiation. This characteristic makes HWRs uniquely suited to the extraction of energy from thorium. In Canada, the toxicity and radiological protection methods dealing with personnel exposure to natural uranium (NU) spent fuel (SF) are well-established, but the corresponding methods for irradiated thorium fuel are not well known. This study uses software to compare the activity and toxicity of irradiated thorium fuel ('thorium SF') against those of NU. Thorium elements, contained in the inner eight elements of a heterogeneous high-burnup bundle having LEU (Low-enriched uranium) in the outer 35 elements, achieve a similar burnup to NU SF during its residence in a reactor, and the radiotoxicity due to fission products was found to be similar. However, due to the creation of such inhalation hazards as U-232 and Th-228, the radiotoxicity of thorium SF was almost double that of NU SF after sufficient time has passed for the decay of shorter-lived fission products. Current radio-protection methods for NU SF exposure are likely inadequate to estimate the internal dose to personnel to thorium SF, and an analysis of thorium in fecal samples is recommended to assess the internal dose from exposure to this fuel. (authors)

Inhalation radiotoxicity of irradiated thorium as a heavy water reactor fuel

Energy Technology Data Exchange (ETDEWEB)

Edwards, G.W.R.; Priest, N.D.; Richardson, R.B. [Atomic Energy of Canada Ltd., Chalk River, Ontario, K0J 1J0 (Canada)

2013-07-01

The online refueling capability of Heavy Water Reactors (HWRs), and their good neutron economy, allows a relatively high amount of neutron absorption in breeding materials to occur during normal fuel irradiation. This characteristic makes HWRs uniquely suited to the extraction of energy from thorium. In Canada, the toxicity and radiological protection methods dealing with personnel exposure to natural uranium (NU) spent fuel (SF) are well-established, but the corresponding methods for irradiated thorium fuel are not well known. This study uses software to compare the activity and toxicity of irradiated thorium fuel ('thorium SF') against those of NU. Thorium elements, contained in the inner eight elements of a heterogeneous high-burnup bundle having LEU (Low-enriched uranium) in the outer 35 elements, achieve a similar burnup to NU SF during its residence in a reactor, and the radiotoxicity due to fission products was found to be similar. However, due to the creation of such inhalation hazards as U-232 and Th-228, the radiotoxicity of thorium SF was almost double that of NU SF after sufficient time has passed for the decay of shorter-lived fission products. Current radio-protection methods for NU SF exposure are likely inadequate to estimate the internal dose to personnel to thorium SF, and an analysis of thorium in fecal samples is recommended to assess the internal dose from exposure to this fuel. (authors)

Irradiations under magnetic field. Measurement of resistivity sample irradiations between 100 and 500 deg C in a swimming-pool reactor

International Nuclear Information System (INIS)

Pauleve, J.; Marchand, A.; Blaise, A.

1964-01-01

An oven is described which enables the irradiation of small samples in the maximum neutron flux of a swimming-pool reactor of 15 MW (Siloe), at temperatures of between 100 and 500 deg.C defined to ± 0,5 deg.C, The oven is very simple from the technological point of view, and has a diameter of only 27 mm, This permits resistivity measurements to be carried out under irradiation in the reactor, or as another example, it enables irradiations in a magnetic field of 5000 oersteds, created by an immersed solenoid. (authors) [fr

Experimental investigation on variation of physical properties of coal samples subjected to microwave irradiation

Science.gov (United States)

Hu, Guozhong; Yang, Nan; Xu, Guang; Xu, Jialin

2018-03-01

The gas drainage rate of low-permeability coal seam is generally less than satisfactory. This leads to the gas disaster of coal mine, and largely restricts the extraction of coalbed methane (CBM), and increases the emission of greenhouse gases in the mining area. Consequently, enhancing the gas drainage rate is an urgent challenge. To solve this problem, a new approach of using microwave irradiation (MWR) as a non-contact physical field excitation method to enhance gas drainage has been attempted. In order to evaluate the feasibility of this method, the methane adsorption, diffusion and penetrability of coal subjected to MWR were experimentally investigated. The variation of methane adsorbed amount, methane diffusion speed and absorption loop for the coal sample before and after MWR were obtained. The findings show that the MWR can change the adsorption property and reduce the methane adsorption capacity of coal. Moreover, the methane diffusion characteristic curves for both the irradiated coal samples and theoriginal coal samples present the same trend. The irradiated coal samples have better methane diffusion ability than the original ones. As the adsorbed methane decreases, the methane diffusion speed increases or remain the same for the sample subjected to MWR. Furthermore, compared to the original coal samples, the area of the absorption loop for irradiated samples increases, especially for the micro-pore and medium-pore stage. This leads to the increase of open pores in the coal, thus improving the gas penetrability of coal. This study provides supports for positive MWR effects on changing the methane adsorption and improving the methane diffusion and the gas penetrability properties of coal samples.

The computer system for the express-analysis of the irradiation samples

International Nuclear Information System (INIS)

Vzorov, I.K.; Kalmykov, A.V.; Korenev, S.A.; Minashkin, V.F.; Sikolenko, V.V.

1999-01-01

The computer system for the express-analysis (SEA) of the irradiation samples is described. The system is working together with the pulse high current electrons and ions source. It allows us to correct irradiation regime in real time. The SEA system automatically measures volt-ampere and volt-farad characteristics, sample resistance by 'four-probe' method, sample capacitor parameters. Its parameters are: in the volt-ampere measuring regime - U max = 200 V, minimal voltage step U sh =0.05 V, voltage accuracy 0.25%; in the capacity measuring regime - capacity measurement diapason 0 - 1600 pF, working frequencies diapason 1 -150 kHz, capacity accuracy 0.5%, voltage shifting diapason 1 - 200 V, minimal step of voltage shifting U sh 0.05 V. The SEA management is performed by IBM/AT computer. The control and measuring apparatus was realized in CAMAC standard. The programmed set consists of the first display procedures, control, treatment and information exit. (author)

Qualities of Patin Fishball Irradiated by Gamma Rays (60Co)

International Nuclear Information System (INIS)

Yarosita FS; Bustami I; Winarti Z; Rindy PT

2004-01-01

An experiment on patin fishball quality using gamma irradiation ( 60 Co) has been conducted. Samples were irradiated at 0, 1, 3 and 5 kGy and stored in refrigerator at temperature 10 o C for sixty days. Samples were analysed every fifteen days, except content of fat and protein that analysed only at the beginning and the end of storage. The purpose of this experiment is to know the quality changes of patin fishball irradiated during storage, by measuring of chemical (content of fat, protein, water, TVB value, pH value) and microbiology (TPC aerobic and anaerobic bacteria) changes. The results showed that irradiation did not affect macro nutrient contents (content of fat, protein and water) of patin fishball during storage but irradiation can affect TVB and pH values. Irradiation at 1 kGy can reduce one logarithmic cycle of total aerobic and anaerobic bacteria. The storage life of irradiated patin fishball treated at 1, 3 and 5 kGy could be extended up to 15, 30 and 60 days, respectively. Control samples the storage life could be extended less than 15 days. (author)

Aspects of Low Temperature Irradiation in Neutron Activation Analysis

International Nuclear Information System (INIS)

Brune, D.

1968-08-01

Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined

Aspects of Low Temperature Irradiation in Neutron Activation Analysis

Energy Technology Data Exchange (ETDEWEB)

Brune, D

1968-08-15

Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined.

Isolation of Enterobacter cowanii in tomatoes after gamma irradiation

International Nuclear Information System (INIS)

Vicalvi, M.C.V.; Solidonio, E.G.; Silva, M.A.; Colaco, W.; Silva, G.R. da; Sena, K.X.F.R de

2013-01-01

The tomato is one of the most consumed fruit in the world. Bacteria of the family Enterobacteriaceae are responsible for large outbreaks of gastroenteritis. Irradiation is a physical method which reduces waste by eliminating spoilage organisms in foods. The objective of this study was to identify and determine the resistance profile of micro-organisms of the family Enterobacteriaceae from irradiated tomatoes. Were used three batches each containing 80 tomatoes, and divided in control and irradiated. The samples were individually properly identified as the irradiation dose applied. The material was subjected to irradiation with gamma rays, for irradiating with a cobalt-60 source, using doses: 1.0, 1.5 and 2 kGy (6,060 kGy/h). For microbiological analysis tomatoes were cut out, and removing the shells to obtain samples weighing 25g. Each sample was transferred to an Erlenmeyer containing sterilized water, stirring the assembly mechanically. Aliquots of the wash waters were sown in differential and selective media. After reisolation, the colonies were subjected to Gram staining then performed biochemical tests for identification. The antibiotic susceptibility tests were performed according to CLSI (Clinical Laboratory Standard Institute). It was isolated three strains of Enterobacter cowanii in tomato samples irradiated with a dose of 1.0 kGy, without isolating the other doses. As for the resistance profile, the strains were resistant to Ampicillin identified. Gamma irradiation at a dose of 1.5 and 2 kGy was effective in tomatoes as well as the micro-organism isolated after irradiation showed no profile of multidrug resistance. (author)

Water born pollutants sampling using porous suction samples

International Nuclear Information System (INIS)

Baig, M.A.

1997-01-01

The common standard method of sampling water born pollutants in the vadoze zone is core sampling and it is followed by extraction of pore fluid. This method does not allow sampling at the same location next time and again later on. There is an alternative approach for sampling fluids (water born pollutants) from both saturated and unsaturated regions of vadose zone using porous suction samplers. There are three types of porous suction samplers, vacuum-operated, pressure-vacuum lysimeters, high pressure vacuum samples. The suction samples are operated in the range of 0-70 centi bars and usually consist of ceramic and polytetrafluorethylene (PTFE). The operation range of PTFE is higher than ceramic cups. These samplers are well suited for in situ and repeated sampling form the same location. This paper discusses the physical properties and operating condition of such samplers to the utilized under our environmental sampling. (author)

Utilization of irradiation on food preservation

International Nuclear Information System (INIS)

Cho, Han Ok; Kwon, Joong Ho; Byun, Myung Woo

1985-04-01

The number of total viable bacteria in chicken meat was reduced by over 90% with irradiation treatments of 5-10 kGy, and also an irradiation dose of yeasts, molds, coliforms, and especially Salmonella for 2-4 weeks of storage. In physicochemical properties of stored chichen, such as water holding capacity, TBA number, UBN, odor, color, overall appearance, cooking quality and organoleptic characteristics, the irradiated samples were superior to the nonirradiated samples, so the freshness of irradiated chicken was retained until 30 days ofter storage at 3-4degC. Commercial fried fish paste was comtaminated by 2.2x10 3 counts in total variable bacteria, 2.8x10 2 counts in yeasts and models, and 1.0x10 2 counts in coliforms, per gram of samples, but irradiation treatment of more than 3 kGy could reduce the microbial load up to 80-90%. As the storage period increased, chemical components of the irradiated samples were better than those of the nonirradiated samples, and the self-life of irradiated groups was extended by 3-4 times as compared with that of nonirradiated groups at room(10-20degC) and low(3-4degC) temperatures without apparent changes in organoleptic properties. Some packaged dried fishes, such as dried cod, dried squid, dried file fish and dried pollack, were preserved by irradiation under the room condictions. After storage of one year the by irradiated samples with doses of 3-8 kGy were found to be marketable resulting from organoleptic observations without showing any storage loss due to microbial and insect factors. (Author)

Irradiation test of HAFM and tag gas samples at the standard neutron field of 'YAYOI'

International Nuclear Information System (INIS)

Iguchi, Tetsuo

1997-03-01

To check the accuracy of helium accumulation neutron fluence monitors (HAFM) as new technique for fast reactor neutron dosimetry and the applicability of tag gas activation analysis to fast reactor failed fuel detection, their samples were irradiated at the standard neutron field of the fast neutron source reactor 'YAYOI' (Nuclear Engineering Research Laboratory, University of Tokyo). Since October in 1996, the HAFM samples such as 93% enriched boron (B) powders of 1 mg and natural B powders of 10 mg contained in vanadium (V) capsule were intermittently irradiated at the reactor core center (Glory hole: Gy) and/or under the leakage neutron field from the reactor core (Fast column: FC). In addition, new V capsules filled with enriched B of 40 mg and Be of 100 mg, respectively, were put into an experimental hole through the blanket surrounding the core. These neutron fields were monitored by the activation foils consisting of Fe, Co, Ni, Au, 235 U, 237 Np etc., mainly to confirm the results obtained from 1995's preliminary works. In particular, neutron flux distributions in the vicinity of irradiated samples were measured in more detail. At the end of March in 1997, the irradiated neutron fluence have reached the goal necessary to produce the detectable number of He atoms more than ∼10 13 in each HAFM sample. Six kinds of tag gas samples, which are the mixed gases of isotopically adjusted Xe and Kr contained in SUS capsules, were separately irradiated three times at Gy under the neutron fluence of ∼10 16 n/cm 2 in average. After irradiation, γ-ray spectra were measured for each sample. Depending on the composition of tag gas mixtures, the different patterns of γ-ray peak spectra from 79 Kr, 125 Xe, etc. produced through tag gas activation were able to be clearly identified. These experimental data will be very useful for the benchmark test of tag gas activation calculation applied to the fast reactor failed fuel detection. (author)

A Comparison of Soil-Water Sampling Techniques

Science.gov (United States)

Tindall, J. A.; Figueroa-Johnson, M.; Friedel, M. J.

2007-12-01

The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey soil. Results indicate that the majority of soil water in well-structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different

Evaluation of aluminum capsules according to ISO 9978 to irradiation of gaseous samples in nuclear reactor

International Nuclear Information System (INIS)

Costa, Osvaldo L. da.; Tiezzi, Rodrigo; Souza, Daiane C.B.; Feher, Anselmo; Moura, Joao A.; Souza, Carla D.; Moura, Eduardo S.; Oliveira, Henrique B.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M.

2015-01-01

Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic press head was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978. (author)

Investigative studies on water contamination in Bangladesh. Primary treatment of water samples at the sampling site

International Nuclear Information System (INIS)

Sera, K.; Islam, Md. Shafiqul; Takatsuji, T.; Nakamura, T.; Goto, S.; Takahashi, C.; Saitoh, Y.

2010-01-01

Arsenic concentration in 13 well waters, 9 pond waters, 10 agricultural waters and a coconut juice taken in Comilla district, Bangladesh, where the problem of arsenic pollution is the most severe, was investigated. High-level arsenic is detected even in the well water which has been kept drinking by the people. Relatively high arsenic concentration was detected for some pond and farm waters even though the sampling was performed just after the rainy season and the waters were expected to be highly diluted. Clear relationship was observed in elemental compositions between the pond water and the coconut juice collected at the edge of the water. These results are expected to become the basic information for evaluating the risk of individual food such as cultured fishes, shrimps and farm products, and for controlling total intakes of arsenic. In order to solve the problem of transportation of water samples internationally, a simple method of target preparation performed at the sampling site was established and its validity was confirmed. All targets were prepared at the sampling sites in this study on the basis of this method. (author)

Microcomputer-based systems for automatic control of sample irradiation and chemical analysis of short-lived isotopes

International Nuclear Information System (INIS)

Bourret, S.C.

1974-01-01

Two systems resulted from the need for the study of the nuclear decay of short-lived radionuclides. Automation was required for better repeatability, speed of chemical separation after irradiation and for protection from the high radiation fields of the samples. A MCS-8 computer was used as the nucleus of the automatic sample irradiation system because the control system required an extensive multiple-sequential circuit. This approach reduced the sequential problem to a computer program. The automatic chemistry control system is a mixture of a fixed and a computer-based programmable control system. The fixed control receives the irradiated liquid sample from the reactor, extracts the liquid and disposes of the used sample container. The programmable control executes the chemistry program that the user has entered through the teletype. (U.S.)

New measurements on water ice photodesorption and product formation under ultraviolet irradiation

Science.gov (United States)

Cruz-Diaz, Gustavo A.; Martín-Doménech, Rafael; Moreno, Elena; Muñoz Caro, Guillermo M.; Chen, Yu-Jung

2018-03-01

The photodesorption of icy grain mantles has been claimed to be responsible for the abundance of gas-phase molecules towards cold regions. Being water a ubiquitous molecule, it is crucial to understand its role in photochemistry and its behaviour under an ultraviolet field. We report new measurements on the ultraviolet (UV) photodesorption of water ice and its H2, OH, and O2 photoproducts using a calibrated quadrupole mass spectrometer. Solid water was deposited under ultra-high-vacuum conditions and then UV-irradiated at various temperatures starting from 8 K with a microwave discharged hydrogen lamp. Deuterated water was used for confirmation of the results. We found a photodesorption yield of 1.3 × 10-3 molecules per incident photon for water and 0.7 × 10-3 molecules per incident photon for deuterated water at the lowest irradiation temperature, 8 K. The photodesorption yield per absorbed photon is given and comparison with astrophysical scenarios, where water ice photodesorption could account for the presence of gas-phase water towards cold regions in the absence of a thermal desorption process, is addressed.

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.

The Effect of Topaz Irradiation to the Quality of Cooling Water Reactor GA Siwabessy

International Nuclear Information System (INIS)

Elisabeth Ratnawati; Kawkab Mustofa; Arif Hidayat

2012-01-01

Topaz irradiation which applied both inside and outside the reactor core is one utilization of the reactor GA Siwabessy. Topaz consists of silicon clusters containing a combination of aluminum, fluorine and hydroxyl, and impurities. The results of the qualitative analysis of the topaz before irradiation detected europium (Eu-152), potassium (K-40) and sodium (Na-24). While the post-irradiation of topaz detected europium (Eu), cobalt (Co), cesium (Cs), tantalum (Ta), scandium (Sc), iron (Fe), Selenium (Se) and potassium (K). These elements might affect the quality of the cooling water. But the results of the qualitative analysis that were carried out to the primary cooling water did not reveal any elements similar to the elements contained in topaz impurities. Most likely this is because most impurities have been caught by the resin trap in purification systems, because of the results of the analysis of the dirt on the resin trap contained elements similar to the impurities Fe and Co topaz. The purification system makes quality primary cooling water is maintained. From the result shows that chemically the quality of primary cooling water is not affected by the topaz irradiation. (author)

Use of Cdse/ZnS quantum dots for sensitive detection and quantification of paraquat in water samples

Energy Technology Data Exchange (ETDEWEB)

Durán, Gema M. [Department of Analytical Chemistry and Food Technology, University of Castilla – La Mancha, Avenida Camilo José Cela, 10, 13004 Ciudad Real (Spain); IRICA (Regional Institute of Applied Scientific Research), Avenida Camilo José Cela, s/n., 13071 Ciudad Real (Spain); Contento, Ana M. [Department of Analytical Chemistry and Food Technology, University of Castilla – La Mancha, Avenida Camilo José Cela, 10, 13004 Ciudad Real (Spain); Ríos, Ángel, E-mail: Angel.Rios@uclm.es [Department of Analytical Chemistry and Food Technology, University of Castilla – La Mancha, Avenida Camilo José Cela, 10, 13004 Ciudad Real (Spain)

2013-11-01

Graphical abstract: -- Highlights: •Analytical use of CdSe/ZnS quantum dots. •Methodology for water solubilization of CdSe/ZnS QDs. •Sensitive and selective reaction with paraquat herbicide. •Application to water samples. -- Abstract: Based on the highly sensitive fluorescence change of water-soluble CdSe/ZnS core-shell quantum dots (QD) by paraquat herbicide, a simple, rapid and reproducible methodology was developed to selectively determine paraquat (PQ) in water samples. The methodology enabled the use of simple pretreatment procedure based on the simple water solubilization of CdSe/ZnS QDs with hydrophilic heterobifunctional thiol ligands, such as 3-mercaptopropionic acid (3-MPA), using microwave irradiation. The resulting water-soluble QDs exhibit a strong fluorescence emission at 596 nm with a high and reproducible photostability. The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection limits, was as low as 3.0 ng L{sup −1}. The lineal range was between 10–5 × 10{sup 3} ng L{sup −1}. RSD values in the range of 71–102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different procedence.

Use of Cdse/ZnS quantum dots for sensitive detection and quantification of paraquat in water samples

International Nuclear Information System (INIS)

Durán, Gema M.; Contento, Ana M.; Ríos, Ángel

2013-01-01

Graphical abstract: -- Highlights: •Analytical use of CdSe/ZnS quantum dots. •Methodology for water solubilization of CdSe/ZnS QDs. •Sensitive and selective reaction with paraquat herbicide. •Application to water samples. -- Abstract: Based on the highly sensitive fluorescence change of water-soluble CdSe/ZnS core-shell quantum dots (QD) by paraquat herbicide, a simple, rapid and reproducible methodology was developed to selectively determine paraquat (PQ) in water samples. The methodology enabled the use of simple pretreatment procedure based on the simple water solubilization of CdSe/ZnS QDs with hydrophilic heterobifunctional thiol ligands, such as 3-mercaptopropionic acid (3-MPA), using microwave irradiation. The resulting water-soluble QDs exhibit a strong fluorescence emission at 596 nm with a high and reproducible photostability. The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection limits, was as low as 3.0 ng L −1 . The lineal range was between 10–5 × 10 3 ng L −1 . RSD values in the range of 71–102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different procedence

Solar UV-treatment of water samples for stripping-voltammetric determination of trace heavy metals in Awash river, Ethiopia

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Gelaneh Woldemichael

2016-03-01

Full Text Available We report about testing a new mobile and sustainable water sample digestion method in a preliminary field trial in Ethiopia. In order to determine heavy metals at the ultra-trace level by stripping voltammetric techniques in water samples from Awash River, we applied our new method of solar UV-assisted sample pretreatment to destroy the relevant interfering dissolved organic matter. The field tests revealed that 24 h of solar UV irradiation were sufficient to achieve the same sample pretreatment results as with classic digestion method based on intense and hard UV. Analytical results of this study suggest that both a hydroelectric power station and agrichemical applications at Koka Lake have increased the levels of the investigated metals zinc, cadmium, lead, copper, cobalt, nickel, and uranium.

Elemental analysis of water and soil environmental samples in Tabuk area by neutron capture gamma-ray spectroscopy techniques

International Nuclear Information System (INIS)

Al-Aseery, Sh.M.; Alamoudi, Z.; Hassan, A.M.

2006-01-01

The prompt and delayed gamma-rays due to neutron capture in the nuclei of the constituent elements of three soil samples and one drinking water sample have been measured. The 252 Cf and 226 Ra/Be isotopic neutron sources are used for neutron irradiation. Also, the hyper pure germanium detection system is used. The soil samples were from Astra, Tadco and El-Gammaz farms, while the water sample was taken from Tabuk city. In case of prompt gamma-ray analysis, a total of 16 elements were identified and the concentration percentage values by weight were calculated for: C, Na, Mg, Al, Si, S, Cl,, Ca, Ti, Cr, Mn, Fe, Co, Zn, Sr ad Pb elements. A comparative study between the results obtained in this work and the results obtained by ICP-MS and EDX-Ray techniques for the same samples is given

Review of irradiation experiments for water reactor safety research

International Nuclear Information System (INIS)

Tobioka, Toshiaki

1977-02-01

A review is made of irradiation experiments for water reactor safety research under way in both commercial power plants and test reactors. Such experiments are grouped in two; first, LWR fuel performance under normal and abnormal operating conditions, and second, irradiation effects on fracture toughness in LWR vessels. In the former are fuel densification, swelling, and the influence of power ramp and cycling on fuel rod, and also fuel rod behavior under accident conditions in in-reactor experiment. In the latter are the effects of neutron exposure level on the ferritic steel of pressure vessels, etc.. (auth.)

Water stale and structure analysis of Konjac irradiation copolymer

International Nuclear Information System (INIS)

Geng Shengrong; Xia Hezhou; Chen Xueling; Ye Lixiu; Hua Yuejin

2011-01-01

To study the absorption performance of Konjac-AA copolymer prepared by using irradiation, the water absorption capacity, sorbent speed and water keeping ability were determined, DSC and TEM analysis were used to investigate the water content and structure characters. The results showed that the largest water absorption speed was 16 g · -1 · min -1 at room temperature, and the largest water absorption was 400 times within 60 minutes. The water absorption was affected by granularity, temperature, ion content and ion type, especially the ion type. The water keeping ability was affected by temperature and time, which was up to 35% of absorbed water when the fully water absorbed copolymer was kept under room temperature for 15 d. The free and bounder water content which could be assimilated by the plants was 99.617%. The water stale copolymer has a three-dimensional spiral structure. (authors)

Characteristics of recycled and electron beam irradiated high density polyethylene samples

International Nuclear Information System (INIS)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo

2015-01-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Characteristics of recycled and electron beam irradiated high density polyethylene samples

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Jessica R.; Gabriel, Leandro; Geraldo, Aurea B.C.; Moura, Eduardo, E-mail: jrcardoso@ipen.br, E-mail: lgabriell@gmail.com, E-mail: ageraldo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Polymers modification by irradiation is a well-known process that allows degradation and cross-linking in concurrent events; this last is expected when an increase of mechanical properties is required. Actually, the interest of recycling and reuse of polymeric material is linked to the increase of plastics ending up in waste streams. Therefore, these both irradiation and recycling process may be conducted to allow a new use to this material that would be discarded by an improvement of its mechanical properties. In this work, the High Density Polyethylene (HDPE) matrix has been recycled five times from original substrate. The electron beam irradiation process was applied from 50 kGy to 200 kGy in both original and recycled samples; in this way, mechanical properties and thermal characteristics were evaluated. The results of applied process and material characterization are discussed. (author)

Microstructural characterization and model of hardening for the irradiated austenitic stainless steels of the internals of pressurized water reactors

International Nuclear Information System (INIS)

Pokor, C.

2003-01-01

The core internals of Pressurized Water Reactors (PWR) are composed of SA 304 stainless steel plates and CW 316 stainless steel bolts. These internals undergo a neutron flux at a temperature between 280 deg C and 380 deg C which modifies their mechanical properties. These modifications are due to the changes in the microstructure of these materials under irradiation which depend on flux, dose and irradiation temperature. We have studied, by Transmission Electron Microscopy, the microstructure of stainless steels SA 304, CW 316 and CW 316Ti irradiated in a mixed flux reactor (OSIRIS at 330 deg C between 0,8 dpa et 3,4 dpa) and in a fast breeder reactor at 330 deg C (BOR-60) up to doses of 40 dpa. Moreover, samples have been irradiated at 375 deg C in a fast breeder reactor (EBR-II) up to doses of 10 dpa. The microstructure of the irradiated stainless steels consists in faulted Frank dislocation loops in the [111] planes of austenitic, with a Burgers vector of [111]. It is possible to find some voids in the solution annealed samples irradiated at 375 deg C. The evolution of the dislocations loops and voids has been simulated with a 'cluster dynamic' model. The fit of the model parameters has allowed us to have a quantitative description of our experimental results. This description of the microstructure after irradiation was coupled together with a hardening model by Frank loops that has permitted us to make a quantitative description of the hardening of SA 304, CW 316 and CW 316Ti stainless steels after irradiation at a certain dose, flux and temperature. The irradiation doses studied grow up to 90 dpa, dose of the end of life of PWR internals. (author)

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)

Studies on the properties of poly(ethylene oxide) R-150 water-swollen hydrogel formed by irradiation

International Nuclear Information System (INIS)

Yang Zhanshan; Zhu Nankang; Yang Shuqin; Qiang Yizhong

2000-01-01

The physical and chemical properties of PEO R-150 water-swollen hydrogel films formed by electron beam irradiation are studied and compared with PEO R-150 hydrogel films. The experimental results show that the irradiation dose and mass fraction of the polymer do not produce a significant effect on the gel fraction, of the PEO R-150 water-swollen hydrogel films (P>0.05). The degrees of swelling of the PEO R-150 water-swollen hydrogel films decrease as the irradiation dose increasing (P 0.05). The results indicate that the saturant crosslinking density, the lowest degree of swelling of the PEO R-150 water-swollen hydrogel films produce and unfavorable effect on their machinery strength

Water and sewage sludge disinfection by irradiation. Pt. 3

International Nuclear Information System (INIS)

Alexandre, D.

1978-01-01

In view of disinfestation of water and sludges qualitative aspects of irradiation are given. Effects of different parameters: pH, dose rate, hydratation, synergism of oxygen, heat and chlorine are examined. No toxic products are created by radiations. Filtrability and decantability of sludges are improved [fr

Fabrication of SERS Active Surface on Polyimide Sample by Excimer Laser Irradiation

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T. Csizmadia

2014-01-01

Full Text Available A possible application of excimer laser irradiation for the preparation of surface enhanced Raman spectroscopy (SERS substrate is demonstrated. A polyimide foil of 125 μm thickness was irradiated by 240 pulses of focused ArF excimer laser beam (λ = 193 nm, FWHM = 20 ns. The applied fluence was varied between 40 and 80 mJ/cm2. After laser processing, the sample was coated with 40 nm silver by PLD in order to create a conducting layer required for the SERS application. The SERS activity of the samples was tested by Raman microscopy. The Raman spectra of Rhodamine 6G aqueous solution (c=10−3 mol/dm3 were collected from the patterned and metalized areas. For areas prepared at 40–60 mJ/cm2 laser fluences, the measured Raman intensities have shown a linear dependence on the applied laser fluence, while above 60 mJ/cm2 saturation was observed. The morphology of the SERS active surface areas was investigated by scanning electron microscopy. Finite element modeling was performed in order to simulate the laser-absorption induced heating of the polyimide foil. The simulation resulted in the temporal and spatial distribution of the estimated temperature in the irradiated polyimide sample, which are important for understanding the structure formation process.

Radon measurement in Malaysia water samples

International Nuclear Information System (INIS)

Ibrahim, A.B.; Rosli Mahat; Yusof Md Amin

1995-01-01

This paper reported the results of the measurement of radon in local water. The water samples collected were rainwater, river water, seawater, well water or ground water at area of State of Selangor and Kuala Lumpur. The samples were collected in scintillation cell ZnS(Ag) through Radon Degassing Unit RDU 200. Alpha activity was counted with scintillation counters RD 200 at energy 5.5 MeV. (author)

Effect of neutron irradiation on vitreous carbon

International Nuclear Information System (INIS)

Kurolenkin, E.I.; Virgil'ev, Yu.S.; Chugunova, T.K.

1989-01-01

The change in mass (m), volume (V), specific electric resistance (ρ), coefficient of linear thermal expansion (α), dynamic elasticity modulus (E), and limit of bending strength (σ) of vitreous carbon are studied upon neutron irradiation. Samples for study were two forms of vitreous carbon obtained by hardening thermally reactive polymers at 900-1,000 degree K. Phenol-formaldehyde (bakelite lacquer A, Bakelite A) and furfural-phenol-formaldehyde (FM-2) resin were used. They were irradiated in the experimental water - water VVR-M reactor between 360-1,030 degree K. The maximal neutron flux was 1.65·10 21 neut/cm 2 . Neutron irradiation of vitreous carbon led to its shrinkage and accompanied weakening. Shrinkage and weakening of vitreous carbon was decreased with an increase of treatment and irradiation temperatures

Solar UV-assisted sample preparation of river water for ultra-trace determination of uranium by adsorptive stripping voltammetry

International Nuclear Information System (INIS)

Woldemichael, G.; Tulu, T.; Flechsig, G.-U.

2012-01-01

The article describes how solar ultraviolet-A radiation can be used to digest samples as needed for voltammetric ultratrace determination of uranium(VI) in river water. We applied adsorptive stripping voltammetry (AdSV) using chloranilic acid as the complexing agent. Samples from the river Warnow in Rostock (Germany) were pretreated with either soft solar UV or wit artificial hard UV from a 30-W source emitting 254-nm light. Samples were irradiated for 12 h, and both methods yielded the same results. We were able to detect around 1 μg.L -1 of uranium(VI) in a sample of river water that also contained dissolved organic carbon at a higher mg.L -1 levels. No AdSV signal was obtained for U(VI) without any UV pre-treatment. Pseudo-polarographic experiments confirmed the dramatic effect of both digestion techniques the the AdSV response. The new method is recommended for use in mobile ultratrace voltammetry of heavy metals for most kinds of natural water samples including tap, spring, ground, sea, and river waters. The direct use of solar radiation for sample pre-treatment represents a sustainable technique for sample preparation that does not consume large quantities of chemicals or energy. (author)

Water sampling techniques for continuous monitoring of pesticides in water

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Šunjka Dragana

2017-01-01

Full Text Available Good ecological and chemical status of water represents the most important aim of the Water Framework Directive 2000/60/EC, which implies respect of water quality standards at the level of entire river basin (2008/105/EC and 2013/39/EC. This especially refers to the control of pesticide residues in surface waters. In order to achieve the set goals, a continuous monitoring program that should provide a comprehensive and interrelated overview of water status should be implemented. However, it demands the use of appropriate analysis techniques. Until now, the procedure for sampling and quantification of residual pesticide quantities in aquatic environment was based on the use of traditional sampling techniques that imply periodical collecting of individual samples. However, this type of sampling provides only a snapshot of the situation in regard to the presence of pollutants in water. As an alternative, the technique of passive sampling of pollutants in water, including pesticides has been introduced. Different samplers are available for pesticide sampling in surface water, depending on compounds. The technique itself is based on keeping a device in water over a longer period of time which varies from several days to several weeks, depending on the kind of compound. In this manner, the average concentrations of pollutants dissolved in water during a time period (time-weighted average concentrations, TWA are obtained, which enables monitoring of trends in areal and seasonal variations. The use of these techniques also leads to an increase in sensitivity of analytical methods, considering that pre-concentration of analytes takes place within the sorption medium. However, the use of these techniques for determination of pesticide concentrations in real water environments requires calibration studies for the estimation of sampling rates (Rs. Rs is a volume of water per time, calculated as the product of overall mass transfer coefficient and area of

Manufacture of electron beam irradiation vessel and its characteristics

International Nuclear Information System (INIS)

Kanazawa, Takao; Haruyama, Yasuyuki; Yotsumoto, Keiichi

1992-05-01

Electron beam irradiation vessel, which is used for the irradiation of samples under an inert or a vacuum atmosphere, is made by considering the temperature control during or after irradiation. The vessel was composed of the temperature controlable samples supporting plate, beam slit with water cooling plate and the insert of thermosensor. The four samples supporting plate was produced with the materials made up of aluminium, stainless steel (SUS304), and copper. The stainless steel supporting plate has a heater inside the cooling pipes for the high temperature treatment of samples without exposure to atmosphere after the irradiation. In this report, the temperature distribution and dose characteristics such as dose distribution and effects of backscattered electron were studied by using several supporting plate and the comparison of the experimental results with the simulated results was also carried out. (author)

Alterations in water and electrolyte absorption in the rat colon following neutron irradiation: influence of neutron component and irradiation dose.

Science.gov (United States)

Dublineau, I; Ksas, B; Joubert, C; Aigueperse, J; Gourmelon, P; Griffiths, N M

2002-12-01

To study the absorptive function of rat colon following whole-body exposure to neutron irradiation, either to the same total dose with varying proportion of neutrons or to the same neutron proportion with an increasing irradiation dose. Different proportions of neutron irradiation were produced from the reactor SILENE using a fissile solution of uranium nitrate (8, 47 and 87% neutron). Water and electrolyte fluxes were measured in the rat in vivo under anaesthesia by insertion into the descending colon of an agarose gel cylinder simulating the faeces. Functional studies were completed by histological analyses. In the first set of experiments, rats received 3.8 Gy with various neutron percentages and were studied from 1 to 14 days after exposure. In the second set of experiments, rats were exposed to increasing doses of irradiation (1-4Gy) with a high neutron percentage (87%n) and were studied at 4 days after exposure. The absorptive capacity of rat colon was diminished by irradiation at 3-5 days, with a nadir at 4 days. The results demonstrate that an increase in the neutron proportion is associated with an amplification of the effects. Furthermore, a delay in the re-establishment of normal absorption was observed with the high neutron proportion (87%n). A dose-dependent reduction of water absorption by rat colon was also observed following neutron irradiation (87%n), with a 50% reduction at 3 Gy. Comparison of this dose-effect curve with the curve obtained following gamma (60)Co-irradiation indicates an RBE of 2.2 for absorptive colonic function in rat calculated at 4 days after exposure.

ASPIRE: An automated sample positioning and irradiation system for radiation biology experiments at Inter University Accelerator Centre, New Delhi

International Nuclear Information System (INIS)

Kothari, Ashok; Barua, P.; Archunan, M.; Rani, Kusum; Subramanian, E.T.; Pujari, Geetanjali; Kaur, Harminder; Satyanarayanan, V.V.V.; Sarma, Asitikantha; Avasthi, D.K.

2015-01-01

An automated irradiation setup for biology samples has been built at Inter University Accelerator Centre (IUAC), New Delhi, India. It can automatically load and unload 20 biology samples in a run of experiment. It takes about 20 min [2% of the cell doubling time] to irradiate all the 20 samples. Cell doubling time is the time taken by the cells (kept in the medium) to grow double in numbers. The cells in the samples keep growing during entire of the experiment. The fluence irradiated to the samples is measured with two silicon surface barrier detectors. Tests show that the uniformity of fluence and dose of heavy ions reaches to 2% at the sample area in diameter of 40 mm. The accuracy of mean fluence at the center of the target area is within 1%. The irradiation setup can be used to the studies of radiation therapy, radiation dosimetry and molecular biology at the heavy ion accelerator. - Highlights: • Automated positioning and irradiation setup for biology samples at IUAC is built. • Loading and unloading of 20 biology samples can be automatically carried out. • Biologicals cells keep growing during entire experiment. • Fluence and dose of heavy ions are measured by two silicon barrier detectors. • Uniformity of fluence and dose of heavy ions at sample position reaches to 2%

Biosynthesis of phenolic compounds and water soluble vitamins in culantro (Eryngium foetidum L. plantlets as affected by low doses of gamma irradiation

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Amina Abd El-Hamid ALY

2010-11-01

Full Text Available Explants obtained from in-vitro propagated plantlets of Culantro (Eryngium foetidum L. were exposed to four dose levels of γ-irradiation (0.0, 10.0, 20.0 and 40.0 Gy to investigate the biosynthesis of phenolic compounds and water soluble vitamins in Culantro fresh plantlets. Among six identified phenolic compounds, the content of p-cumaric acid was the highest in the extracts, followed by caffeic acid, coumarin, benzoic acid, salicylic acid and apigenin. Significant increases were observed at dose 40.0 Gy (61.66 mg/g d.w. for flavonoids, 18.02 mg/g d.w, for flavonone and 5.06 mg/g d.w for anthocyanin compared to control. On the other hand, the flavonols were decreased by increasing the irradiation dose. Vitamin C was increased in irradiated samples and this increase was in correlation with irradiation dose level. Thiamin, riboflavin and nicotinic acid were enhanced by the applied dose level 10 Gy. In addition, folic acid was enhanced by the dose levels 20 and 40 Gy and not detected for the control and 10 Gy treatments. Meanwhile, pyridoxine was decreased by increasing the irradiation dose level. The results obtained suggested that both low doses of γ-irradiation and tissue culture technique could be used to produce plantlets with high amount of phenolic compounds and water soluble vitamins.

Characterization of modified PVDF membrane by gamma irradiation for non-potable water reuse.

Science.gov (United States)

Lim, Seung Joo; Kim, Tak-Hyun; Shin, In Hwan

2015-01-01

Poly(vinylidene fluorine) (PVDF) membranes were grafted by gamma-ray irradiation and were sulfonated by sodium sulfite to modify the surface of the membranes. The characteristics of the modified PVDF membranes were evaluated by the data of Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FE-SEM), the contact angle of the membrane surface and the water permeability. From the results of FT-IR, XPS and FE-SEM, it was shown that the modified membranes were successfully grafted by gamma-ray irradiation and were sulfonated. The content of oxygen and sulfur increased with the monomer concentration, while the content of fluorine sharply decreased. The pore size of the modified membranes decreased after gamma-ray irradiation. The contact angle and the water permeability showed that the hydrophilicity of the modified membranes played a role in determining the membrane performance. The feasibility study of the modified PVDF membranes for using non-potable water reuse were carried out using a laboratory-scale microfiltration system. Grey wastewater was used as the influent in the filtration unit, and permeate quality satisfied non-potable water reuse guidelines in the Republic of Korea.

Water state and TEM analysis of Konjac irradiation copolymer

International Nuclear Information System (INIS)

Geng Shengrong; Xia Hezhou; Chen Xueling; Ye Lixiu; Hua Yuejin

2012-01-01

To study the absorption performance of Konjac-AA copolymer prepared by irradiation, the water absorbent capacity, sorbent speed and water keeping ability was determined and DSC and TEM analysis were used to explore the water content and structure characters. The results showed that on room temperature the largest water absorption speed was 16 g · g -1 · min -1 at, and the largest water absorption was 400 times at 60 min. The water absorption was affected by granularity, temperature, ion content and ion type, especially the ion type, the water keeping ability was affected by temperature and time, which was up to 35% while the fully water absorbed copolymer was kept under room temperature for 15 d. The free and bounder water content which was assimilated by the plants was 99.617%. The gel stale co polymer has a three-dimensional structure of spiral, which was constituted by spherical objects of varying sizes. (authors)

Effects of water stress on irradiance acclimation of leaf traits in almond trees.

Science.gov (United States)

Egea, Gregorio; González-Real, María M; Baille, Alain; Nortes, Pedro A; Conesa, María R; Ruiz-Salleres, Isabel

2012-04-01

Photosynthetic acclimation to highly variable local irradiance within the tree crown plays a primary role in determining tree carbon uptake. This study explores the plasticity of leaf structural and physiological traits in response to the interactive effects of ontogeny, water stress and irradiance in adult almond trees that have been subjected to three water regimes (full irrigation, deficit irrigation and rain-fed) for a 3-year period (2006-08) in a semiarid climate. Leaf structural (dry mass per unit area, N and chlorophyll content) and photosynthetic (maximum net CO(2) assimilation, A(max), maximum stomatal conductance, g(s,max), and mesophyll conductance, g(m)) traits and stem-to-leaf hydraulic conductance (K(s-l)) were determined throughout the 2008 growing season in leaves of outer south-facing (S-leaves) and inner northwest-facing (NW-leaves) shoots. Leaf plasticity was quantified by means of an exposure adjustment coefficient (ε=1-X(NW)/X(S)) for each trait (X) of S- and NW-leaves. Photosynthetic traits and K(s-l) exhibited higher irradiance-elicited plasticity (higher ε) than structural traits in all treatments, with the highest and lowest plasticity being observed in the fully irrigated and rain-fed trees, respectively. Our results suggest that water stress modulates the irradiance-elicited plasticity of almond leaves through changes in crown architecture. Such changes lead to a more even distribution of within-crown irradiance, and hence of the photosynthetic capacity, as water stress intensifies. Ontogeny drove seasonal changes only in the ε of area- and mass-based N content and mass-based chlorophyll content, while no leaf age-dependent effect was observed on ε as regards the physiological traits. Our results also indicate that the irradiance-elicited plasticity of A(max) is mainly driven by changes in leaf dry mass per unit area, in g(m) and, most likely, in the partitioning of the leaf N content.

Research of pneumatic control transmission system for small irradiation samples

International Nuclear Information System (INIS)

Bai Zhongxiong; Zhang Haibing; Rong Ru; Zhang Tao

2008-01-01

In order to reduce the absorbed dose damage for the operator, pneumatic control has been adopted to realize the rapid transmission of small irradiation samples. On/off of pneumatic circuit and directions for the rapid transmission system are controlled by the electrical control part. The main program initializes the system and detects the location of the manual/automatic change-over switch, and call for the corresponding subprogram to achieve the automatic or manual operation. Automatic subprogram achieves the automatic sample transmission; Manual subprogram completes the deflation, and back and forth movement of the radiation samples. This paper introduces in detail the implementation of the system, in terms of both hardware and software design. (authors)

Identification of irradiated dry ingredients on the basis of starch damage

International Nuclear Information System (INIS)

Farkas, J.; Koncz, A.; Sharif, M.M.

1990-01-01

Irradiated samples of several ground spices, i.e. white pepper, black pepper, nutmeg, and ginger showed considerable loss of viscosity of their heat gelatinized suspensions as compared to that of unirradiated controls. Viscosimetric studies were also performed with a number of untreated pepper samples of various origin to estimate the ''natural'' variation of rheological properties. Following such preliminary experiments, storage studies were performed with ground black pepper samples of various water activity levels, either untreated or treated with gamma radiation doses of 4, 8, 16, and 32 kGy, respectively. Subsequent to irradiation, the samples were stored for 100 days at room temperature and under relative humidities in equilibrium with their respective moisture content (25%, 50%, and 75% R.H. resp.). Statistically significant differences of the apparent viscosity of heat gelatinized suspensions remained detectable between untreated samples and those irradiated with 8 kGy or higher doses during the entire storage period. However, the apparent viscosity of high-moisture (75% E.R.H.) untreated samples was decreasing during long-term storage. Differences between viscosities of untreated and irradiated samples were enlarged when measured at elevated temperatures such as 50 0 C in the rotational viscosimeter, or in the boiling-water bath of a Falling Number apparatus. (author)

Design and building of a homemade sample changer for automation of the irradiation in neutron activation analysis technique

International Nuclear Information System (INIS)

Gago, Javier; Hernandez, Yuri; Baltuano, Oscar; Bedregal, Patricia; Lopez, Yon; Urquizo, Rafael

2014-01-01

Because the RP-10 research reactor operates during weekends, it was necessary to design and build a sample changer for irradiation as part of the automation process of neutron activation analysis technique. The device is formed by an aluminum turntable disk which can accommodate 19 polyethylene capsules, containing samples to be sent using the pneumatic transfer system from the laboratory to the irradiation position. The system is operate by a control switchboard to send and return capsules in a variable preset time and by two different ways, allowing the determination of short, medium and long lived radionuclides. Also another mechanism is designed called 'exchange valve' for changing travel paths (pipelines) allowing the irradiated samples to be stored for a longer time in the reactor hall. The system design has allowed complete automation of this technique, enabling the irradiation of samples without the presence of an analyst. The design, construction and operation of the device is described and presented in this article. (authors).

Study of the iron corrosion at the interface of different media (water, air) submitted to protons irradiation; Etude de la corrosion du fer a l'interface de differents milieux (eau, air) soumis a l'irradiation de protons

Energy Technology Data Exchange (ETDEWEB)

Lapuerta, S

2005-10-15

During the deep geological disposal, stainless steel containers of the vitrified waste will be put in carbon steel overpacks. After the closing of the storage site, overpacks will be in contact with a humid air and a radioactive medium. After hundred years, overpacks could be in contact with water radiolysis in an anoxic medium. In this context, my PhD work is a fundamental study which is the understanding of the corrosion mechanisms of pure iron under proton irradiation. This corrosion is affected by the contact of iron with different atmospheres (air, nitrogen) and water. In the case of the atmospheric iron corrosion under irradiation, we have studied the influence of the proton beam flux. During this work, we have characterized the structure of the oxides formed at the iron surface. The structure formed does not correspond to iron oxides and hydroxides indexed. However, we have shown that the oxide structure is close to that of lepidocrocite and bernalite. Moreover, we have determined the oxygen diffusion coefficient in iron under irradiation and we have shown that the irradiation accelerates of 6 orders of magnitude the iron corrosion. In addition, the irradiations which were realized in different gas have put in evidence the negligible role of nitrates, and the importance of the O{sub 2}/H{sub 2}O coupling on the iron corrosion. Finally, we have shown the influence of the relative humidity, the maximum of the corrosion being observed for a relative humidity close to 45%. In the case of the iron corrosion in aqueous media under irradiation, the influence of the oxygen dissolved in water has been studied using a surface marker. We have put in evidence that the corrosion is twice more significant in aerated medium than in deaerated medium. Moreover, the influence of radicals has been shown. An irradiated sample is more corroded than a sample put in contact with a H{sub 2}O{sub 2} solution. Finally, the follow-up of the iron potential under irradiation have shown

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

Water absorption, cooking properties and cell structure of gamma irradiated soybeans

International Nuclear Information System (INIS)

Kang, I.J.; Byun, M.W.

1996-01-01

Gamma irradiation was applied to soybean(Glycine max.), Hwangkeum, at dose levels of 0, 5, 10 and 20 kGy to improve the physical properties of soybeans. The time to reach a fixed moisture content was reduced depending on the increment of soaking temperatures and applied irradiation dose levels. Irradiation at 5~20 kGy resulted in reduction in soaking time of the soybeans by about 3~6 hrs at soaking temperature of 20°. The degree of cooking of soybeans in boiling water was determined by measuring the maximum cutting force of cotyledon. The cutting force to reach complete cooking was about 145g/g. Irradiation at 5~20 kGy resulted in a reduction of cooking time of soybeans by 55~75% as compared to the nonirradiated soybean. In electron microscopic observation of seed coat inner, the parenchyma of nonirradiated soybean showed tight fibrillar structure, whereas that of irradiated soybeans showed loosened and deformed structure. The microstructure of compressed cells and cotyledon epidermis was also deformed by gamma irradiation. In subcellular structure of cotyledon, the roundness of protein body was deformed and changed to spike shape at 20 kGy. Also, the size of lipid body decreased as the irradiation dose levels increased

Comparison of gamma irradiation and steam explosion pretreatment for ethanol production from agricultural residues

International Nuclear Information System (INIS)

Wang, Ke-qin; Xiong, Xing-yao; Chen, Jing-ping; Chen, Liang; Su, Xiaojun; Liu, Yun

2012-01-01

It was evaluated the influence of gamma irradiation and steam explosion pretreatment on the components and the water-soluble sugars of rice straw. Compared with the steam explosion pretreated rice straw, cellucose, hemicellucose and lignin for irradiation pretreated rice sample were much more greatly degraded and the relative content of glucose was significantly enhanced from 6.58% to 47.44%. Interestingly, no glucuronide acid was detected in irradiation pretreated rice straw, while glucuronide acid with the content from 8.5 mg/g to 9.2 mg/g was obtained in steam explosion pretreated sample. Followed by enzymatic hydrolysis, higher concentration of reducing sugars (including glucose and xylose) of irradiation pretreated rice sample (90.3 mg/g) was obtained, which was approximately 2.4- and 1.1- fold higher of the unpretreated (37.2 mg/g) and of steam explosion pretreated sample (85.4 mg/g). To further verify the effectiveness of irradiation pretreatment, characterizations of rice straw, corn stalk and bagasse by an integrated process of dilute acid/enzymatic hydrolysis and irradiation pretreatment were also investigated. -- Highlights: ► We compare irradiation and steam explosion pretreatments for bioethanol production. ► We examine changes in compositions of the components and the water-soluble sugars. ► No glucuronide acid was detected in gamma irradiation pretreated rice straw. ► We evaluate an integrated method of acid/enzyme-hydrolyzed irradiation pretreatment.

Independent CO2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, Task 2.50.05

International Nuclear Information System (INIS)

Stojic, M.; Pavicevic, M.

1964-01-01

This report contains the following volumes V and VI of the Project 'Independent CO 2 loop for cooling the samples irradiated in RA reactor vertical experimental channels': Design project of the dosimetry control system in the independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels, and Safety report for the Independent CO 2 loop for cooling the samples irradiated in the RA reactor vertical experimental channels [sr

Study of the mechanisms controlling the oxide growth under irradiation: characterization of irradiated zircaloy-4 and Zr-1 Nb-O oxide scales

International Nuclear Information System (INIS)

Bossis, Ph.; Thomazet, J.; Lefebvre, F.

2002-01-01

In PWRs, the Zr-1Nb-O alloy shows a marked enhancement in corrosion resistance in comparison with Zircaloy-4. The aim of this work is to analyze the reasons for these different behaviors and to determine the respective nature of the oxide growth controlling mechanisms under irradiation. Samples taken from Zircaloy-4 irradiated 1, 2, and 4 cycles and Zr-1Nb-O irradiated 1 and 3 cycles have been systematically characterized by optical microscopy, SEM coupled with image analysis, hydride distribution, and XRD. Specific TEM characterizations have been performed on the Zr-1Nb-O samples. A XPS analysis of a nonirradiated sample is also reported. It has been shown that under irradiation the slow oxidation kinetics of the Zr-1Nb-O alloy is associated with very regular metal-oxide interface and oxide layer. On the contrary, the accelerated oxidation kinetics of Zircaloy-4 is associated with highly perturbed metal-oxide interface and oxide layer. On both irradiated alloys, cracks are observed to initiate preferentially above the delayed parts of the oxidation front. Hydrogen intake during water oxidation in PWR environment is found to be much lower on the Zr-1Nb-O alloy than on Zircaloy-4. More β-ZrO 2 is found on the oxide layer formed on Zircaloy-4 than on Zr-1NbO after oxidation in PWR. Classical irradiation-induced microstructural evolution is observed in the Zr-1Nb-O metallic alloy after 3 cycles, i.e., a fine β-Nb precipitation. β-Nb precipitates are observed to undergo a delayed oxidation associated with a crystalline to amorphous transformation. After water oxidation in autoclave, a pronounced Nb segregation is detected on the oxide surface of a Zr-1Nb-O sample. These results suggest that the oxidation kinetics of Zircaloy-4 is controlled essentially by oxygen diffusion through the inner barrier layer, which is significantly accelerated under irradiation. The oxidation kinetics of Zr-1Nb-O is controlled by both oxygen diffusion through the inner barrier and by

Development of natural water irradiation system for the production of 18F at the cyclotron of IPEN

International Nuclear Information System (INIS)

Santos, Liliane Landini Mota

1994-01-01

A system for the irradiation of water was developed at the CV-28 compact cyclotron of IPEN-CNEN/SP. This system was tested and its viability verified with the irradiation of circulating water (+- 66 ml) and the radioisotope produced this way was 18 F. The 18 F is a radioisotope that can be used in the diagnosis of brain and heart diseases, through the PET technique (Positron Emission Tomography). The whole irradiation system is automatically controlled by means of a panel specially designed for this purpose. The chemical separation of 18 F after the irradiation was carried out using an Anionic Exchange Resin DOWEX 1X8 (100-200 mesh) and Potassium Carbonate as elutant. The 18 F was obtained in aqueous solution in the chemical form of Fluoride (F), with maximum retention of 100 % . The maximum elution yield obtained was 86 %. The minimum specific activity obtained was 6.623 X 10 5 MBq/mmol. The production yields obtained were, on average, (4.81 +- 0.42) MBq/mu A.h. The limit of current tested was 34 mu A, with water temperature of 71 deg C in the exit of target-holder. The maximum length of the irradiation was 2 hours. The windows of aluminium and silver tested behaved on a safe way, as well as the two cooling systems: BAR (Cooling Water Pump) and independent. Heat transfer calculations were made concerning the water that was being irradiated, and the results (author)

Design and fabrication of water control unit for IASCC irradiation test

International Nuclear Information System (INIS)

Mori, Yuichiro; Takeuchi, Yutaka; Matsunami, Kiyotaka; Kosaki, Kazuhiko; Suzuki, Tomio; Hayashi, Motomitsu; Ide, Kiyoshi

2004-01-01

In relation to the aging of LWR, the Irradiation Assisted Stress Corrosion Cracking (IASCC) has been regarded as a significant and urgent issue for the reliability of in-core components of LWR, therefore the irradiation research project which was planned by Nuclear and Industrial Safety Agency is now being done under the cooperation of Industry-Government-Academia such as Japan Nuclear Energy Safety Organization, Institute of Research and Innovation (IRI), Central Research Institute of Electric Power Industry, Japan Atomic Energy Research Institute (JAERI), power companies, makers of LWR, and universities. Then at Japan Material Testing Reactor (JMTR) of JAERI, the irradiation test of the material for BWR is being carried out. This paper describes the introduction about the Water Control Unit (WCU) for IASCC irradiation test. The WCU was designed and installed into JMTR by Kawasaki Heavy Industries, LTD, based on the order from JAERI, IRI, and so on. (author)

MCNPX calculations of dose rate distribution inside samples treated in the research gamma irradiating facility at CTEx

Energy Technology Data Exchange (ETDEWEB)

Rusin, Tiago; Rebello, Wilson F.; Vellozo, Sergio O.; Gomes, Renato G., E-mail: tiagorusin@ime.eb.b, E-mail: rebello@ime.eb.b, E-mail: vellozo@cbpf.b, E-mail: renatoguedes@ime.eb.b [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Nuclear; Vital, Helio C., E-mail: vital@ctex.eb.b [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

2011-07-01

A cavity-type cesium-137 research irradiating facility at CTEx has been modeled by using the Monte Carlo code MCNPX. The irradiator has been daily used in experiments to optimize the use of ionizing radiation for conservation of many kinds of food and to improve materials properties. In order to correlate the effects of the treatment, average doses have been calculated for each irradiated sample, accounting for the measured dose rate distribution in the irradiating chambers. However that approach is only approximate, being subject to significant systematic errors due to the heterogeneous internal structure of most samples that can lead to large anisotropy in attenuation and Compton scattering properties across the media. Thus this work is aimed at further investigating such uncertainties by calculating the dose rate distribution inside the items treated such that a more accurate and representative estimate of the total absorbed dose can be determined for later use in the effects-versus-dose correlation curves. Samples of different simplified geometries and densities (spheres, cylinders, and parallelepipeds), have been modeled to evaluate internal dose rate distributions within the volume of the samples and the overall effect on the average dose. (author)

MCNPX calculations of dose rate distribution inside samples treated in the research gamma irradiating facility at CTEx

International Nuclear Information System (INIS)

Rusin, Tiago; Rebello, Wilson F.; Vellozo, Sergio O.; Gomes, Renato G.; Silva, Ademir X.

2011-01-01

A cavity-type cesium-137 research irradiating facility at CTEx has been modeled by using the Monte Carlo code MCNPX. The irradiator has been daily used in experiments to optimize the use of ionizing radiation for conservation of many kinds of food and to improve materials properties. In order to correlate the effects of the treatment, average doses have been calculated for each irradiated sample, accounting for the measured dose rate distribution in the irradiating chambers. However that approach is only approximate, being subject to significant systematic errors due to the heterogeneous internal structure of most samples that can lead to large anisotropy in attenuation and Compton scattering properties across the media. Thus this work is aimed at further investigating such uncertainties by calculating the dose rate distribution inside the items treated such that a more accurate and representative estimate of the total absorbed dose can be determined for later use in the effects-versus-dose correlation curves. Samples of different simplified geometries and densities (spheres, cylinders, and parallelepipeds), have been modeled to evaluate internal dose rate distributions within the volume of the samples and the overall effect on the average dose. (author)

Spectrophotometric analysis of irradiated spices

Energy Technology Data Exchange (ETDEWEB)

Josimovic, L; Cudina, I

1987-01-01

Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

Effect of gamma irradiation and storage on lutein and zeaxanthin in liquid, frozen and dried egg yolk samples

International Nuclear Information System (INIS)

Mine Uygun-Saribay; Ece Ergun; Turhan Koeseoglu

2014-01-01

The aim of this study was to monitor the effects of gamma irradiation and storage on the content of lutein and zeaxanthin in egg yolk samples. Liquid, frozen and dried egg samples were subjected to gamma irradiation doses of 0, 1, 2 and 3 kGy followed by storage of liquid samples at +4 ± 1 deg C for 21 days, frozen samples at -18 ± 1 deg C and dried samples at room temperature for 1 year. The xanthophyll concentrations were determined by high-performance liquid chromatography-diode array detector. It was observed that concentrations of both lutein and zeaxanthin were decreased significantly (P < 0.05) after irradiation and during storage. The mechanism for radiation-induced degradation was proposed as radical formation which initiate chain reactions. It was suggested that during storage active radical species and oxygen caused the degradation. (author)

Physical properties of irradiation exposured food

International Nuclear Information System (INIS)

Hayashi, Toru; Todoroki, Setsuko; Kono, Sumio; Kikuchi, Yuji; Otobe, Kazunori

1997-01-01

A distinguishing method of irradiation effects on white and black pepper was established by using measurement of viscosity. This method makes possible to distinguish the irradiated pepper independent on the place of production, period of storage and kinds of viscometer. The method is described as follows: Add 40 ml of water to 4 g of pepper powder which produces a suspension of pepper in water. 2 ml of 33% caustic solution is added to the suspension, immediatly heating it in boiling water for 30 min for gelatinization. Then, it is permitted to stand for 3.5 hours and measured its viscosity. Amount of starch in pepper sample is determined previously. The obtained viscosity divided by the amount of starch is used as a parameter. (S.Y.)

Changes in the Lipid Fraction of Eel Gills after Ionizing Irradiation in Vivo and a Shift from Fresh to Sea Water

DEFF Research Database (Denmark)

Hansen, Heinz Johs. Max

1975-01-01

Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ-radiation and four of the irradiated group and four of the nonirradiated control group were transferred to sea water. The rest remained in tap water. Three days later all were incubated with 14 C...... been irradiated and transferred to sea water. By measuring lipid biosynthesis in gill tissue it was thus possible to show an interaction between the effect of ionizing irradiation and the salinity of the environment, in agreement with previous biological findings....

EFFECT OF THE CRITICAL IRRADIANCE ON PHOTOVOLTAIC WATER PUMP DISCHARGE UNDER EGYPTIAN CONDITIONS

Directory of Open Access Journals (Sweden)

Mamdouh Abbas HELMY

2015-04-01

Full Text Available The present investigation aimed to study the effect of critical irradiance due to changing tilt angle of PV panel and tracking sun on submersible pump discharge. The authors used solar tracker and suitable tilt angle for the panel to increase the time interval during which the water pump operates. For the same irradiance collected by the PV, all systems pump the same amount of water, although they occur at different periods of the day. The pump itself 'does not know whether the electric power comes from any processes, as long as it has the same intensity.

Investigation of the effect of power ultrasound on the nucleation of water during freezing of agar gel samples in tubing vials.

Science.gov (United States)

Kiani, Hossein; Sun, Da-Wen; Delgado, Adriana; Zhang, Zhihang

2012-05-01

Nucleation, as an important stage of freezing process, can be induced by the irradiation of power ultrasound. In this study, the effect of irradiation temperature (-2 °C, -3 °C, -4 °C and -5 °C), irradiation duration (0s, 1s, 3s, 5s, 10s or 15s) and ultrasound intensity (0.07 W cm(-2), 0.14 W cm(-2), 0.25 W cm(-2), 0.35 W cm(-2) and 0.42 W cm(-2)) on the dynamic nucleation of ice in agar gel samples was studied. The samples were frozen in an ethylene glycol-water mixture (-20 °C) in an ultrasonic bath system after putting them into tubing vials. Results indicated that ultrasound irradiation is able to initiate nucleation at different supercooled temperatures (from -5 °C to -2 °C) in agar gel if optimum intensity and duration of ultrasound were chosen. Evaluation of the effect of 0.25 W cm(-2) ultrasound intensity and different durations of ultrasound application on agar gels showed that 1s was not long enough to induce nucleation, 3s induced the nucleation repeatedly but longer irradiation durations resulted in the generation of heat and therefore nucleation was postponed. Investigation of the effect of ultrasound intensity revealed that higher intensities of ultrasound were effective when a shorter period of irradiation was used, while lower intensities only resulted in nucleation when a longer irradiation time was applied. In addition to this, higher intensities were not effective at longer irradiation times due to the heat generated in the samples by the heating effect of ultrasound. In conclusion, the use of ultrasound as a means to control the crystallization process offers promising application in freezing of solid foods, however, optimum conditions should be selected. Copyright © 2011 Elsevier B.V. All rights reserved.

Irradiation Assisted Stress Corrosion Cracking of austenitic stainless steels

Energy Technology Data Exchange (ETDEWEB)

Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Irradiation Assisted Stress Corrosion Cracking (IASCC) of austenitic stainless steels in oxygenated high temperature water was studied. The IASCC failure has been considered as a degradation phenomenon potential not only in the present light water reactors but rather common in systems where the materials are exposed simultaneously to radiation and water environments. In this study, effects of the material and environmental factors on the IASCC of austenitic stainless steels were investigated in order to understand the underlying mechanism. The following three types of materials were examined: a series of model alloys irradiated at normal water-cooled research reactors (JRR-3M and JMTR), the material irradiated at a spectrally tailored mixed-spectrum research reactor (ORR), and the material sampled from a duct tube of a fuel assembly used in the experimental LMFBR (JOYO). Post-irradiation stress corrosion cracking tests in a high-temperature water, electrochemical corrosion tests, etc., were performed at hot laboratories. Based on the results obtained, analyses were made on the effects of alloying/impurity elements, irradiation/testing temperatures and material processing, (i.e., post-irradiation annealing and cold working) on the cracking behavior. On the basis of the analyses, possible remedies against IASCC in the core internals were discussed from viewpoints of complex combined effects among materials, environment and processing factors. (author). 156 refs.

EPR and UV spectrometry investigation of sucrose irradiated with carbon particles

International Nuclear Information System (INIS)

Karakirova, Yordanka; Yordanov, Nicola D.

2010-01-01

Solid state/EPR (SS/EPR) dosimeters of carbon ions irradiated sucrose are studied with EPR, and their water solutions - with UV spectroscopy. Doses between 20 and 200 Gy are used with linear energy transfer (LET) values for carbon ions of 63, 77, 96 and 230 keV μm -1 . After irradiation all samples show typical for irradiated sucrose EPR and UV spectra. The obtained data are compared with those previously reported for nitrogen particles and gamma rays irradiated sucrose. The identical shape of both the EPR and UV spectra of irradiated with various type radiation samples suggests that generated free radicals are not influenced by the nature of radiation. The lack of difference in the line width of the separate lines or the whole EPR spectrum, obtained for gamma and heavy particles irradiation, suggests negligible spin-spin interaction among the radiation-generated free radicals in the samples. The linear dependence of the EPR response on the absorbed dose radiation is found to be higher when generated by gamma rays, than by the same absorbed dose of heavy particles. In addition, the EPR response for carbon ions is higher than that for nitrogen ions. Water solutions of irradiated sucrose exhibit UV spectrum with absorption maximum at 267 nm, attributed to the recombination products of free radicals. The UV band intensity depends on the absorbed dose radiation. The UV spectra obtained for carbon, nitrogen and gamma rays irradiated sucrose are also compared.

Measurements of three dimensional residual stress distribution on laser irradiated spot

International Nuclear Information System (INIS)

Tanaka, Hirotomo; Akita, Koichi; Ohya, Shin-ichi; Sano, Yuji; Naito, Hideki

2004-01-01

Three dimensional residual stress distributions on laser irradiated spots were measured using synchrotron radiation to study the basic mechanism of laser peening. A water-immersed sample of high tensile strength steel was irradiated with Q-switched and frequency-doubled Nd:YAG laser. The residual stress depth profile of the sample was obtained by alternately repeating the measurement and surface layer removal by electrolytic polishing. Tensile residual stresses were observed on the surface of all irradiated spots, whereas residual stress changed to compressive just beneath the surface. The depth of compressive residual stress imparted by laser irradiation and plastic deformation zone increased with increasing the number of laser pulses irradiated on the same spot. (author)

Identification of gamma-irradiated fruit juices by EPR spectroscopy

International Nuclear Information System (INIS)

Aleksieva, K.I.; Dimov, K.G.; Yordanov, N.D.

2014-01-01

The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to “cellulose-like” EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical “sugar-like“ spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation. - Highlights: • The EPR analysis of juices, nectars and syrups proves that the sample has been irradiated. • Two sample preparation procedures were used. • The stability of the radiation induced EPR signals was studied over 2 months. • Application of European standards can be extended for irradiated juices and syrups

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.

Pre-irradiation tests on U-Si alloys

International Nuclear Information System (INIS)

Howe, L.M.; Bell, L.G.

1958-05-01

Pre-irradiation tests of hardness, density, electrical resistivity, and corrosion resistance as well as metallographic and X-ray examinations were undertaken on U-Si core material, which had been co-extruded in Zr--2, in order that the effect of irradiation on alloys in the epsilon range could be assessed. In addition, a study of the epsilonization of arc-melted material was undertaken in order to rain familiarity with the epsilonization process and to obtain information on the corrosion behaviour of epsilonized material. Sheathed U-Si samples in the epsilonized and de-epsilonized conditions have been irradiated in the X-2 loop, with a water temperature of 275 o C. The samples have been examined after 250 MWD/Tonne and show no dimensional change. (author)

Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination

International Nuclear Information System (INIS)

Al-Gabr, Hamid Mohammad; Zheng, Tianling; Yu, Xin

2013-01-01

The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log 10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log 10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations. - Highlights: • As a disinfectant, chlorine is more effective than UV in inactivating Aspergillus flavus. • As a combined method, UV irradiation followed by chlorination shows high efficiency. • UV irradiation can improve effectiveness of chlorination in reducing Aspergillus flavus

Determination of irradiated reactor uranium in soil samples in Belarus using 236U as irradiated uranium tracer.

Science.gov (United States)

Mironov, Vladislav P; Matusevich, Janna L; Kudrjashov, Vladimir P; Boulyga, Sergei F; Becker, J Sabine

2002-12-01

This work presents experimental results on the distribution of irradiated reactor uranium from fallout after the accident at Chernobyl Nuclear Power Plant (NPP) in comparison to natural uranium distribution in different soil types. Oxidation processes and vertical migration of irradiated uranium in soils typical of the 30 km relocation area around Chernobyl NPP were studied using 236U as the tracer for irradiated reactor uranium and inductively coupled plasma mass spectrometry as the analytical method for uranium isotope ratio measurements. Measurements of natural uranium yielded significant variations of its concentration in upper soil layers from 2 x 10(-7) g g(-1) to 3.4 x 10(-6) g g(-1). Concentrations of irradiated uranium in the upper 0-10 cm soil layers at the investigated sampling sites varied from 5 x 10(-12) g g(-1) to 2 x 10(-6) g g(-1) depending on the distance from Chernobyl NPP. In the majority of investigated soil profiles 78% to 97% of irradiated "Chernobyl" uranium is still contained in the upper 0-10 cm soil layers. The physical and chemical characteristics of the soil do not have any significant influence on processes of fuel particle destruction. Results obtained using carbonate leaching of 236U confirmed that more than 60% of irradiated "Chernobyl" uranium is still in a tetravalent form, ie. it is included in the fuel matrix (non-oxidized fuel UO2). The average value of the destruction rate of fuel particles determined for the Western radioactive trace (k = 0.030 +/- 0.005 yr(-1)) and for the Northern radioactive trace (k = 0.035 + 0.009 yr(-1)) coincide within experimental errors. Use of leaching of fission products in comparison to leaching of uranium for study of the destruction rate of fuel particles yielded poor coincidence due to the fact that use of fission products does not take into account differences in the chemical properties of fission products and fuel matrix (uranium).

Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil

Energy Technology Data Exchange (ETDEWEB)

Ray, Phoebe Z. [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Chen, Huan [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Podgorski, David C. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Future Fuels Institute, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); McKenna, Amy M. [National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005 (United States); Tarr, Matthew A., E-mail: mtarr@uno.edu [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States)

2014-09-15

Graphical abstract: Sunlight oxygenates petroleum. - Highlights: • Oxidation seen in water-soluble oil fraction after exposure to simulated sunlight. • Oxygen addition occurred across a wide range of carbon number and DBE. • Oil compounds were susceptible to addition of multiple oxygens to each molecule. • Results provide understanding of fate of oil on water after exposure to sunlight. - Abstract: In order to assess the impact of sunlight on oil fate, Macondo well oil from the Deepwater Horizon (DWH) rig was mixed with pure water and irradiated with simulated sunlight. After irradiation, the water-soluble organics (WSO) from the dark and irradiated samples were extracted and characterized by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Liquid–liquid extraction yielded two fractions from dark and irradiated water/oil mixtures: acidic WSOs (negative-ion electrospray (ESI)), and base/neutral WSOs (positive-ion ESI) coupled to FT-ICR MS to catalog molecular-level transformations that occur to Macondo-derived WSOs after solar irradiation. Such direct measure of oil phototransformation has not been previously reported. The most abundant heteroatom class detected in the irradiated WSO acid fractions correspond to molecules that contain five oxygens (O{sub 5}), while the most abundant acids in the dark samples contain two oxygen atoms per molecule (O{sub 2}). Higher-order oxygen classes (O{sub 5}–O{sub 9}) were abundant in the irradiated samples, but <1.5% relative abundance in the dark sample. The increased abundance of higher-order oxygen classes in the irradiated samples relative to the dark samples indicates that photooxidized components of the Macondo crude oil become water-soluble after irradiation. The base/neutral fraction showed decreased abundance of pyridinic nitrogen (N{sub 1}) concurrent with an increased abundance of N{sub 1}O{sub x} classes after irradiation. The predominance of higher

Detection of some irradiated spices on the basis of radiation induced damage of starch

International Nuclear Information System (INIS)

Farkas, J.; Sharif, M.M.; Koncz, A.

1990-01-01

Untreated and irradiated samples of spices were suspended in water, alkalized, and after heat-gelatinization, the apparent viscosity was determined by a rotational viscometer. Several spices, i.e. white pepper, black pepper, nutmeg and ginger showed considerable loss of viscosity as a function of γ radiation dose in the dose range required for microbial decontamination of natural spices. Less promising results were obtained with spices such as allspice, garlic powder, and onion powder forming low-viscosity heat-treated suspensions even when unirradiated viscometric studies were also performed with a number of pepper samples of various origin to estimate the ''natural'' variation of rheological properties. Irradiation and storage studies were performed with ground black pepper samples of moisture contents in equilibrium with air of 25%, 50% and 75% R.H., respectively, either untreated or irradiated with 4, 8, 16 or 32 kGy, to study the effect of equilibrium relative humidity and storage time on detectability of radiation treatment. During the entire storage period of 100 days, statistically significant differences of the apparent viscosities of heat-gelatinized suspensions remained detectable between untreated samples and those irradiated with 8 kGy or higher doses. The apparent viscosity of high-moisture (75% E.R.H.) untreated samples was decreasing during long-term storage. Differences between viscosities of untreated and irradiated samples were enlarged when measured at elevated temperatures such as 50 0 C in the rotational viscometer, or in the boiling-water bath of a falling number apparatus. Other analytical indices such as onset and peak temperatures of gelatinization endotherms by DSC (damaged starch content), by colorimetry, reducing sugar content, alcohol-induced turbidity of hot water extracts of pepper samples, have been changed less dramatically by irradiation than the apparent viscosity of the gelatinized suspensions. (author)

Microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid for the determination of sulfonamides in environmental water samples.

Science.gov (United States)

Song, Ying; Wu, Lijie; Lu, Chunmei; Li, Na; Hu, Mingzhu; Wang, Ziming

2014-12-01

An easy, quick, and green method, microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid, was first developed and applied to the extraction of sulfonamides in environmental water samples. 1-Ethy-3-methylimidazolium hexafluorophosphate, which is a solid-state ionic liquid at room temperature, was used as extraction solvent in the present method. After microwave irradiation for 90 s, the solid-state ionic liquid was melted into liquid phase and used to finish the extraction of the analytes. The ionic liquid and sample matrix can be separated by freezing and centrifuging. Several experimental parameters, including amount of extraction solvent, microwave power and irradiation time, pH of sample solution, and ionic strength, were investigated and optimized. Under the optimum experimental conditions, good linearity was observed in the range of 2.00-400.00 μg/L with the correlation coefficients ranging from 0.9995 to 0.9999. The limits of detection for sulfathiazole, sulfachlorpyridazine, sulfamethoxazole, and sulfaphenazole were 0.39, 0.33, 0.62, and 0.85 μg/L, respectively. When the present method was applied to the analysis of environmental water samples, the recoveries of the analytes ranged from 75.09 to 115.78% and relative standard deviations were lower than 11.89%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Microbiological and technological quality of corn and faba bean as affected by varying levels of gamma irradiation

International Nuclear Information System (INIS)

Youssef, B.M.; Swailam, H.M.H.; Elsamahy, S.K.

1995-01-01

Samples of corn and faba bean grains subjected to different doses of gamma radiation. The microbiological, physical and physicochemical properties of irradiated grains were assessed as compared with control. corn starch was extracted from irradiated corn grains and its quality evaluated. The results showed that increasing irradiation dose caused a gradual reduction in total bacterial counts, counts of spore forming bacteria, coliform group, mold and yeast in corn grains. The same trend applies to the effect of storage period for irradiated samples. 7.5 KGy was found to eliminate all microorganisms. Increasing irradiation dose from 1.0 to 10.0 KGy caused an increase in soundness number and water absorption of corn grains, acidity, reducing power and solubility of isolated starch while the swelling power and water binding capacity of starch were reduced. The rate of change during storage period was lower in the irradiated samples than in the untreated ones. 7 figs., 3 tabs

MO-FG-CAMPUS-JeP1-03: Luminescence Imaging of Water During Proton Beam Irradiation for Range Estimation

International Nuclear Information System (INIS)

Yamamoto, S; Komori, M; Toshito, T; Watabe, H

2016-01-01

Purpose: Since proton therapy has the ability to selectively deliver a dose to a target tumor, the dose distribution should be accurately measured. A precise and efficient method to evaluate the dose distribution is desired. We found that luminescence was emitted from water during proton irradiation and thought this phenomenon could be used for estimating the dose distribution. Methods: For this purpose, we placed water phantoms set on a table with a spot-scanning proton-therapy system, and luminescence images of these phantoms were measured with a high-sensitivity cooled charge coupled device (CCD) camera during proton-beam irradiation. We also conducted the imaging of phantoms of pure-water, fluorescein solution and acrylic block. We made three dimensional images from the projection data. Results: The luminescence images of water phantoms during the proton-beam irradiations showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. The image of the pure-water phantom also showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had 14.5% shorter proton range than that of water; the proton range in the acrylic phantom was relatively matched with the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 sec. Three dimensional images were successfully obtained which have more quantitative information. Conclusion: Luminescence imaging during proton-beam irradiation has the potential to be a new method for range estimations in proton therapy.

MO-FG-CAMPUS-JeP1-03: Luminescence Imaging of Water During Proton Beam Irradiation for Range Estimation

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, S; Komori, M [Nagoya University, Nagoya, Aichi (Japan); Toshito, T [Nagoya Proton Therapy Center, Nagoya, Aichi (Japan); Watabe, H [Tohoku University, Sendai, Miyagi (Japan)

2016-06-15

Purpose: Since proton therapy has the ability to selectively deliver a dose to a target tumor, the dose distribution should be accurately measured. A precise and efficient method to evaluate the dose distribution is desired. We found that luminescence was emitted from water during proton irradiation and thought this phenomenon could be used for estimating the dose distribution. Methods: For this purpose, we placed water phantoms set on a table with a spot-scanning proton-therapy system, and luminescence images of these phantoms were measured with a high-sensitivity cooled charge coupled device (CCD) camera during proton-beam irradiation. We also conducted the imaging of phantoms of pure-water, fluorescein solution and acrylic block. We made three dimensional images from the projection data. Results: The luminescence images of water phantoms during the proton-beam irradiations showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. The image of the pure-water phantom also showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had 14.5% shorter proton range than that of water; the proton range in the acrylic phantom was relatively matched with the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 sec. Three dimensional images were successfully obtained which have more quantitative information. Conclusion: Luminescence imaging during proton-beam irradiation has the potential to be a new method for range estimations in proton therapy.

Effect of gamma irradiation combined with hot water treatment on the texture, pulp color and sensory quality of ''Nahng Glahng Wahn'' mangoes

International Nuclear Information System (INIS)

Lacroix, M.; Jobin, M.; Beliveau, M.; Gagnon, M.

1992-01-01

Mangoes (Mangifera indica L.) from Thailand of the 'Nahng Glahng Wahn' variety were irradiated with a 60 Co source at a dose of 0.63 kGy and a dose rate of 9.23 kGy/hr, with or without a hot water treatment prior to irradiation. The irradiation treatment had little effect on the texture and preserved the yellow color in the pulp. Test of sensory evaluation revealed that irradiated mango pulp was preferred for overall appearance, taste, texture and palatability. The appearance of whole irradiated mangoes was also preferred over that of the control mangoes. However, no significant differences were observed between irradiated and hot water dipped irradiated mangoes for all characteristics studied in mangoes pulp. The results showed that these treatments (hot water dip plus irradiation or irradiation alone) are useful and non-destructive methods to preserve consumer acceptability

Disinfection of sludge and waste-water by irradiation with electrons of low accelerating voltage

International Nuclear Information System (INIS)

Holl, P.; Schneider, H.

1975-01-01

From the point of view of hygiene, sewage sludge and water accumulating in ever increasing quantities, some of which is used in agriculture, represent a potential threat to the health of man and beast, as well as to the environment. It is known that these chains of infection can be broken up by ionizing radiation. The use of natural ionizing radiation or electron radiation with high accelerating voltage has not been accepted in practice because the radiation cannot be cut off and the investment cost for electron accelerators with an accelerating voltage of more than 1 MV is very high. These disadvantages may be overcome by using an electron accelerator with low accelerating voltage. Complex experiments have shown that it is not necessary to adapt the thickness of sewage sludge or water layer to the range of electrons. The layer to be irradiated may be much thicker if the substrate is revolved during irradiation. The advantages of this method are low accelerating voltage for the electrons and hence less costly radiation shielding, complete absorption of the radiated energy by the substrate, and low investment and operating cost. The sterilizing effect of the process can be explained by the secondary reactions that take place in the water, in addition to the primary reactions, when irradiating with high specific ionizing density. It is known from experiments carried out by Muenzner that water irradiated with electrons of high specific ionization density, when added to bacterial cultures, will destroy them. This is explained by the Weiss radical theory of water, with reaction products such as H 2 , O 2 and H 2 O 2 . The success of this process is shown by experiments with Escherichia coli, tap water to which Salmonella senftenberg were added, and by the content of Enterobacteriaceae in various sludges as a function of the irradiation period, as well as by the rate at which various invariable species of strongilide larvae, eggs of Ascaris suum, Fasciola hepatica and

Influence of 60Co γ irradiation pre-treatment on characteristics of hot air drying sweet potato slices

International Nuclear Information System (INIS)

Jiang Ning; Liu Chunquan; Li Dajing; Liu Xia; Yan Qimei

2012-01-01

The influences of irradiation, hot air temperature and thicknesses of the slices on the characters of dehydration and surface temperature of 60 Co γ-rays irradiated sweet potato were investigated. Meanwhile, microscopic observation and determination of water activity of irradiated sweet potato were conducted. The results show that the drying rate and the surface temperature rose with the increasing of irradiation dose. When the dry basis moisture content was 150%, the drying rate of the samples were 1.92, 1.97, 2.05, 2.28, 3.12% /min while the irradiation dose were 0, 2, 5, 8, 10 kGy, and the surface temperature were 48.5 ℃, 46.3℃, 44.5 ℃, 42.2 ℃, 41.5 ℃, respectively. With higher air temperature and thinner of the sweet potato slices, the dehydration of the irradiated sweet potato slices were faster. The drying speed of sweet potato slices at 85 ℃ was 170 min faster than that of 65 ℃. The drying speed of 7 mm sweet potato slices was 228 min faster than that of 3 mm sample. The cell wall and the vacuole of the sweet potato slices were broken after irradiation, and its water activity increased with the increase is radiation dose. The water activity of the irradiated samples were 0.92, 0.945, 0.958, 0.969, 0.979 with the irradiation doses of 0, 2, 5, 8, 10 kGy, respectively. The hot air drying rate, surface temperature and water activity of sweet potato are significantly impacted by irradiation. The conclusion provides a theoretical foundation for further processing technology of combined radiation and hot air drying sweet potato. (authors)

Kinetics of radiolysis of irradiated ligno celluloses into soluble products in water and rumen liquid

International Nuclear Information System (INIS)

Tukenmez, I.; Bakioglu, A.T.; Ersen, M.S.

1997-01-01

In order to increase the low bio hydrolysis of ligno celluloses in biotechnological and biological processes where these materials are used as raw materials and ruminant feed, the substrates were pretreated with irradiation to induce radiolytic depolymerisation and then kinetics of their radiolysis into soluble products in water and rumen liquid were analyzed. Wheat straw used as a representative lignocellulose substrate was irradiated at 0-2.5 MGy doses at 20''o''C with an optimum equilibrium humidity of 6.6% in Cs-137 gamma irradiator with a dose rate of 1.8 kGy/h, and soluablefractions in water and in situ rumen liquid were determined gravimetrically. Based on these data, a reaction mechanism was proposed for the radiolysis of ligno celluloses into soluble fractions. From the corresponding reaction rate equations with this mechanism a dose dependent kinetics was derived for the radiolysis of ligno celluloses into water/rumen liquid-soluble products. Defined by this kinetics, the threshold doses for the radiolysis of the substrate into water/rumen liquid-soluble products were respectively found 80.6 kGy and 186.0 kGy, and fractional radiolytic decomposition yields 0.193 MGy''-1''.It was emphasized that developed kinetic models may be used for the process design of irradiation pretreatments to improve the bio hydrolysis of ligno celluloses.(2figs. and 17 refs.)

DNA damage focus analysis in blood samples of minipigs reveals acute partial body irradiation.

Directory of Open Access Journals (Sweden)

Andreas Lamkowski

Full Text Available Radiation accidents frequently involve acute high dose partial body irradiation leading to victims with radiation sickness and cutaneous radiation syndrome that implements radiation-induced cell death. Cells that are not lethally hit seek to repair ionizing radiation (IR induced damage, albeit at the expense of an increased risk of mutation and tumor formation due to misrepair of IR-induced DNA double strand breaks (DSBs. The response to DNA damage includes phosphorylation of histone H2AX in the vicinity of DSBs, creating foci in the nucleus whose enumeration can serve as a radiation biodosimeter. Here, we investigated γH2AX and DNA repair foci in peripheral blood lymphocytes of Göttingen minipigs that experienced acute partial body irradiation (PBI with 49 Gy (± 6% Co-60 γ-rays of the upper lumbar region. Blood samples taken 4, 24 and 168 hours post PBI were subjected to γ-H2AX, 53BP1 and MRE11 focus enumeration. Peripheral blood lymphocytes (PBL of 49 Gy partial body irradiated minipigs were found to display 1-8 DNA damage foci/cell. These PBL values significantly deceed the high foci numbers observed in keratinocyte nuclei of the directly γ-irradiated minipig skin regions, indicating a limited resident time of PBL in the exposed tissue volume. Nonetheless, PBL samples obtained 4 h post IR in average contained 2.2% of cells displaying a pan-γH2AX signal, suggesting that these received a higher IR dose. Moreover, dispersion analysis indicated partial body irradiation for all 13 minipigs at 4 h post IR. While dose reconstruction using γH2AX DNA repair foci in lymphocytes after in vivo PBI represents a challenge, the DNA damage focus assay may serve as a rapid, first line indicator of radiation exposure. The occurrence of PBLs with pan-γH2AX staining and of cells with relatively high foci numbers that skew a Poisson distribution may be taken as indicator of acute high dose partial body irradiation, particularly when samples are available

Effect of gamma irradiation on microbiological, chemical and sensory characteristics of aniseed (pimpinella anisum)

International Nuclear Information System (INIS)

Al-Bachir, M.

2007-01-01

Seeds of anise (pimpinella anisum) were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60 Co package irradiator. Irradiated and unirradiated samples were stored at room temperature. Microbial population on seeds, total and inorganic soluble solids in water extract and sensory properties of the latter were evaluated after 0, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the aerobic plate counts of aniseed. Immediately after irradiation, the total soluble solids in an extract of irradiated seeds were greater than those of unirradiated ones. The total soluble solids in an extract of irradiated and un-irradiated seeds increased after 6 and 12 months of storage. There were no significant differences (p>0.05) in inorganic soluble solids between the water extract of irradiated and unirradiated aniseeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of aniseed water extract tested immediately after irradiation. However, after 12 months of storage, no significant differences (P>0.05) were found in color, taste or flavor between extract of irradiated and unirradiated seeds. (author)

Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

International Nuclear Information System (INIS)

Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

2010-03-01

Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

Assessment of the total uranium concentration in surface and underground water samples from the Caetite region, Bahia, Brazil

International Nuclear Information System (INIS)

Silva, Julia Grasiela Batista; Geraldo, Luiz Paulo; Yamazaki, Ione Makiko

2011-01-01

At the region of Caetite, BA, it is located the largest uranium mine in exploration at present days in Brazil. During the uranium extraction process, it may be having an environmental contamination by this heavy metal due to rain water and other natural transport mechanism, with potential exposition risk to the local population. The aim of this work was to investigate the total uranium concentration in surface and underground water samples collected at the Caetite region, using the nuclear track registration technique (SSNTD) in a polycarbonate plastic. A 100 mL volume of water samples were initially treated in 10 mL of HNO 3 (PA) and concentrated by evaporation at a temperature around 80 deg C. The resulting residue was diluted to a total volume of 25 mL without pass it to a filter. About 10 μL of this solution was deposited on the plastic detector surface (around 1.0 cm 2 area) together with 5 μL of a Cyastat detergent solution (5%) and evaporated under an infrared lamp. All the resulting deposits of non volatile constituents were irradiated, together with a uranium standard sample, at the IPEN-IEA-R1 (3.5 MW) nuclear reactor for approximately 3 min. After irradiations, chemical etching of the plastic detectors was carried out at 60 deg C, for 65 min. in a NaOH (6N) solution. The fission tracks were counted scanning all the deposit area of the polycarbonate plastic detector with a system consisting of an optical microscope together with a video camera and TV monitor. The average values of uranium concentrations obtained in this work ranged from (0.95±0.19) μg.L -1 to (25.60±3.3) μg.L -1 . These results were compared to values reported in the literature for water samples from other regions and discussed in terms of safe limits recommended by WHO -World Health Organization and CONAMA - Conselho Nacional do Meio Ambiente. (author)

Assessment of the total uranium concentration in surface and underground water samples from the Caetite region, Bahia, Brazil

Energy Technology Data Exchange (ETDEWEB)

Silva, Julia Grasiela Batista; Geraldo, Luiz Paulo [Centro Universitario da Fundacao Educacional de Barretos (UNIFEB), (SP) (Brazil); Yamazaki, Ione Makiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

At the region of Caetite, BA, it is located the largest uranium mine in exploration at present days in Brazil. During the uranium extraction process, it may be having an environmental contamination by this heavy metal due to rain water and other natural transport mechanism, with potential exposition risk to the local population. The aim of this work was to investigate the total uranium concentration in surface and underground water samples collected at the Caetite region, using the nuclear track registration technique (SSNTD) in a polycarbonate plastic. A 100 mL volume of water samples were initially treated in 10 mL of HNO{sub 3} (PA) and concentrated by evaporation at a temperature around 80 deg C. The resulting residue was diluted to a total volume of 25 mL without pass it to a filter. About 10 {mu}L of this solution was deposited on the plastic detector surface (around 1.0 cm{sup 2} area) together with 5 {mu}L of a Cyastat detergent solution (5%) and evaporated under an infrared lamp. All the resulting deposits of non volatile constituents were irradiated, together with a uranium standard sample, at the IPEN-IEA-R1 (3.5 MW) nuclear reactor for approximately 3 min. After irradiations, chemical etching of the plastic detectors was carried out at 60 deg C, for 65 min. in a NaOH (6N) solution. The fission tracks were counted scanning all the deposit area of the polycarbonate plastic detector with a system consisting of an optical microscope together with a video camera and TV monitor. The average values of uranium concentrations obtained in this work ranged from (0.95{+-}0.19) {mu}g.L{sup -1} to (25.60{+-}3.3) {mu}g.L{sup -1}. These results were compared to values reported in the literature for water samples from other regions and discussed in terms of safe limits recommended by WHO -World Health Organization and CONAMA - Conselho Nacional do Meio Ambiente. (author)

Biological samples positioning device for irradiations on a radial channel at the nuclear research reactor

International Nuclear Information System (INIS)

Rodriguez Gual, Maritza; Mas Milian, Felix; Deppman, Airton; Pinto Coelho, Paulo Rogerio

2010-01-01

For the demand of an experimental device for biological samples positioning system for irradiations on a radial channel at the nuclear research reactor in operation was constructed and started up a device for the place and remove of the biological samples from the irradiation channels without interrupting the operation of the reactor. The economical valuations are effected comparing with another type of device with the same functions. This work formed part of an international project between Cuba and Brazil that undertook the study of the induced damages by various types of ionizing radiation in DNA molecules. Was experimentally tested the proposed solution, which demonstrates the practical validity of the device. As a result of the work, the experimental device for biological samples irradiations are installed and operating in the radial beam hole No3(BH3) for more than five years at the IEA-R1 Brazilian research reactor according to the solicited requirements the device. The designed device increases considerably the type of studies can be conducted in this reactor. Its practical application in research taking place in that facility, in the field of radiobiology and dosimetry, and so on is immediate

Water sampling device for fuel rod failure monitoring

International Nuclear Information System (INIS)

Oogami, Hideaki; Echigoya, Hironori; Matsuoka, Tesshi.

1991-01-01

The device of the present invention accurately samples coolants in a channel box as sampling water even if the upper end of the channel box of a fuel assembly is positioned at the same height or lower than the upper end of an upper lattice plate. An existent device comprises an outer cap, an inner cap, an air supply pipe and a water sampling tube. In addition, the device of the present invention comprises a sealing material disposed at the end of the outer cap for keeping liquid sealing with the upper lattice plate and a water level monitoring pipe extended to lower than the inner cap passing through the liquid sealing of the outer cap for sucking the atmosphere in the outer cap. Pressurized air is sent through the air supply pipe, to lower the water level of the coolants in the outer cap and the water level monitoring pipe sucks the pressurized air, by which the inside and the outside of the channel box are partitioned. Subsequently, if the sample water is sampled by a sampling tube, sampling water which enables accurate evaluation for radioactivity concentration in the fuel assembly can be obtained. (I.S.)

Spectrophotometric Determination of Boron in Environmental Water Samples

International Nuclear Information System (INIS)

San San; Khin Win Kyi; Kwaw Naing

2002-02-01

The present paper deals with the study on the methods for the determination of boron in the environmental water samples. The standard methods which are useful for this determination are discussed thoroughly in this work. Among the standard methods approved by American Public Health Association, the carmine method was selected for this study. Prior to the determination of boron in the water samples, the precision and accuracy of the methods of choice were examined by using standard boron solutions. The determination of Boron was carried out by using water samples, waste water from Aquaculture Research Centre, University of Yangon, the Ayeyarwady River water near Magway Myathalon Pagoda in Magway Division, ground water from Sanchaung Township, and tap water from Universities' Research Centre, University of Yangon. Analyses of these water samples were done and statistical treatment of the results was carried out. (author)

Sterilization of dry beverages and condiments for hospital patients by gamma irradiation

International Nuclear Information System (INIS)

Maha, Munsiah

1995-01-01

This study was done to determine the suitable irradiation conditions for sterilyzing several kinds of dry beverages and condiments, i.e. tea, coffee, milk powder, cacao powder, nutrisari, tropicana slim, pepper, salt, sugar and soy sauce. Each sample was vacuum-packed in nylon laminate pouches, then irradiated up to 30 kGy at liquid nitrogen and room temperatures, and stored at room temperature. The odour, flavor, and colour of the samples were evaluated subjectively immediately after irradiation and after storage. Radiation-sterilization dose for each sample was determined using the method BI set out by the AAMI based on bioburden information. The effect of dissolving in boiling water on the bioburden of the samples was also determined. The results showed that dissolving in boiling water could eliminate only a small portion of the bioburden. Irradiation caused significant changes on the colour, flavour and odour of the samples, especially when irradiation was done at room temperature. In general, irradiation conducted at liquid nitrogen temperature could reduce the negative changes to acceptable levels. Sterilization doses for SAL of 10 -3 were found to be 23.1 kGy for sea, 18.1 kGy for coffee (Kapal api), 19.9 kGy for milk powder (Dancow), 15.8 kGy for cacao powder (van Houten), 26.2 kGy for pepper, 19.7 kGy for sugar, 12.8 kGy for coffee (Torabica Duo), 11.7 kGy for nutrisari, 12.2 kGy for soy sauce and 11.2 kGy for Tropicana Slim. (author) 8 refs, 7 tabs

AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl

OpenAIRE

Gaynutdinov, R; Vainshtein, DI; Hak, SJ; Tolstikhina, A; Den Hartog, HW

2003-01-01

AFM investigations are reported for heavily, electron irradiated NaCl crystals in ultra high vacuum (UHV) in the non-contact mode-with an UHV AFM/STM Omicron system. To avoid chemical reactions between the radiolytic Na and oxygen and water, the irradiated samples were cleaved and prepared for the experiments in UHV At the surface of freshly cleaved samples, we have observed sodium nano-precipitates with shapes, which depend on the irradiation dose and the volume fraction of the radiolytic Na...

Effect of electron beam irradiation on post harvest quality of Agaricus bisporus

International Nuclear Information System (INIS)

Zhang Juanpin; Xing Zengtao; Bai Bing; Song Weiguo

2011-01-01

The effects of electron beam irradiation on fresh-keeping of Agaricus bisporus was studied after sporecarp samples were irradiated at 1.0, 2.0, 3.0 and 4.0 kGy and then stored at 4 degree C for 14d. The contents of water-soluble vitamins, amino acids and sugars were measured. Results showed that the contents of water-soluble sugars, amino acids, and aneurin, lactochrome, nicotinic acid in sporecarp did not significantly change after irradiation. However, asoribic acid was sensitive to irradiation, and the content was significantly reduced 31.1% at the dose of 4.0 kGy. It is concluded that 2 kGy irradiation can effectively prolong the shelf life, and almost no significant effect on the nutrient components of Agaricus bisporus. (authors)

Identification of gamma-irradiated fruit juices by EPR spectroscopy

Science.gov (United States)

Aleksieva, K. I.; Dimov, K. G.; Yordanov, N. D.

2014-10-01

The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to "cellulose-like" EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical "sugar-like" spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation.

Thermal imaging of levitated fresh and salt water drops during laser irradiation

Science.gov (United States)

Brownell, Cody; Biggs, Harrison

2017-11-01

Simulation of high energy laser propagation and scattering in the maritime environment is problematic, due to the high likelihood of turbulence, fog, and rain or sea spray within the beam path. Considering large water drops (diameters of approximately 1-mm), such as those found in a light rain, an incident high energy laser will lead to rapid evaporation of the water drop as it traverses the beam path. In this work we present surface temperature measurements of a water drop obtained using a FLIR IR camera. The drop is acoustically levitated, and subject to a continuous wave laser with a wavelength of 1070-nm and a mean irradiance of approximately 800 W/cm2. These measurements show that the steady-state surface temperature of the drop is well below the saturation temperature, and for pure substances the equilibrium temperature decreases with decreasing drop volume similar to observations with smaller aqueous aerosols. Temperature non-uniformity within the drop is also assessed from statistics of the surface temperature fluctuations. Preliminary results from irradiated salt water drops show notably different behavior from fresh water drops, including temperature spikes as the drop volume decreases and occasional nucleate boiling. Acknowledge support from ONR #N00014-17-WX-00031.

Assessment of irradiation effects on beryllium reflector and heavy water tank of JRR-3M

Energy Technology Data Exchange (ETDEWEB)

Murayama, Yoji; Kakehuda, Kazuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

The JRR-3M, a swimming pool type research reactor with beryllium and heavy water reflectors, has been operated since 1990. Since the beryllium reflectors are close to fuel and receive high fast neutron fluence in a relatively short time, they may be subject to change their dimensions by swelling due mostly to entrapped helium gaseous. This may bend the reflectors to the outside and narrow gaps between the reflectors and the fuel elements. The gaps have been measured with an ultrasonic thickness gage in an annual inspection. The results in 1996 show that the maximum of expansion in the diametral directions was 0.6 mm against 1.6 mm of a managed value for replacement of the reflector. A heavy water tank of the JRR-3M is made of aluminum alloy A5052. Surveillance tests of the alloy have been conducted to evaluate irradiation effects of the heavy water tank. Five sets of specimens of the alloy have been irradiated in the beryllium reflectors where fast neutron flux is higher than that in the heavy water tank. In 1994, one set of specimens had been unloaded and carried out the post-irradiation tests. The results show that the heavy water tank preserved satisfactory mechanical properties. (author)

An analytical two-flow model to simulate the distribution of irradiance in coastal waters with a wind-roughed surface and bottom reflectance

Science.gov (United States)

Ma, Wei-Ming

1997-06-01

An analytical two-flow model is derived from the radiative transfer equation to simulate the distribution of irradiance in coastal waters with a wind-roughed surface and bottom reflectance. The model utilizes unique boundary conditions, including the surface slope of the downwelling and upwelling irradiance as well as the influence of wind and bottom reflectance on simulated surface reflectance. The developed model provides a simple mathematical concept for understanding the irradiant light flux and associated processes in coastal or fresh water as well as turbid estuarine waters. The model is applied to data from the Banana River and coastal Atlantic Ocean water off the east coast of central Florida, USA. The two-flow irradiance model is capable of simulating realistic above-surface reflectance signatures under wind-roughened air-water surface given realistic input parameters including a specular flux conversion coefficient, absorption coefficient, backscattering coefficient, atmospheric visibility, bottom reflectance, and water depth. The root-mean-squared error of the calculated above-surface reflectances is approximately 3% in the Banana River and is less than 15% in coastal Atlantic Ocean off the east of Florida. Result of the subsurface reflectance sensitivity analysis indicates that the specular conversion coefficient is the most sensitive parameter in the model, followed by the beam attenuation coefficient, absorption coefficient, water depth, backscattering coefficient, specular irradiance, diffuse irradiance, bottom reflectance, and wind speed. On the other hand, result of the above-surface reflectance sensitivity analysis indicates that the wind speed is the most important parameter, followed by bottom reflectance, attenuation coefficient, water depth, conversion coefficient, specular irradiance, downwelling irradiance, absorption coefficient, and backscattering coefficient. Model results depend on the accuracy of these parameters to a large degree and

UMTRA project water sampling and analysis plan, Maybell, Colorado

International Nuclear Information System (INIS)

1994-06-01

This water sampling and analysis plan (WSAP) describes planned water sampling activities and provides the regulatory and technical basis for ground water sampling in 1994 at the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Maybell, Colorado. The WSAP identifies and justifies sampling locations, analytical parameters, and sampling frequencies at the site. The ground water data will be used for site characterization and risk assessment. The regulatory basis for the ground water and surface water monitoring activities is derived from the EPA regulations in 40 CFR Part 192 (1993) and the proposed EPA standards of 1987 (52 FR 36000). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site. This WSAP also includes a summary and the results of water sampling activities from 1989 through 1992 (no sampling was performed in 1993)

Sampling art for ground-water monitoring wells in nuclide migration

International Nuclear Information System (INIS)

Liu Wenyuan; Tu Guorong; Dang Haijun; Wang Xuhui; Ke Changfeng

2010-01-01

Ground-Water sampling is one of the key parts in field nuclide migration. The objective of ground-water sampling program is to obtain samples that are representative of formation-quality water. In this paper, the ground-water sampling standards and the developments of sampling devices are reviewed. We also designed the sampling study projects which include the sampling methods, sampling parameters and the elementary devise of two types of ground-Water sampling devices. (authors)

Natural Radioactivity Pattern of Surabaya Water Environmental Samples

International Nuclear Information System (INIS)

Rosidi; Agus Taftazani

2007-01-01

The gross β radioactivity and natural radionuclide of Surabaya environmental samples pattern have been evaluated. The environmental samples were chosen randomly at 12 locations. The environment samples were water (fresh, estuary and coastal), sediment, eichhornia crassipes (Mart) Solms, Mangrove (Rhizophora stylosa), (Moolgarda delicatus) fish and (Johnius (Johnieops) borneensis) (Sharpnose hammer croaker) fish. The water sample was evaporated; the sediment sample was dried and ground; the biotic samples was burnt at the temperature 500 °C ; The gross β measurement using GM detector and the radionuclides has been identified by γ spectrometer. From the investigation results could be concluded that the natural radioactivity of environmental samples was very low. gross-β of water samples were lower than the threshold value of local government regulation of Surabaya no: 2 year 2004 (1 Bq/L). The distribution of gross-β activity of eichhornia crassipes (Mart) Solms was higher than the other biotic, water and sediment samples as well as the accumulation of radionuclides in the water organism was taken place. The result of identification using γ spectrometer has detected 7 of radionuclides, i.e 210 Pb, 212 Pb, 214 Pb, 208 Tl, 214 Bi, 228 Ac, and 40 K in all sample. The distribution factor of sediment F D was less than bioaccumulation factor of biotic F B and it indicates that there the radionuclide accumulation migration follows the pattern of water - sediment - biotic sample. (author)

TEM examination of irradiated zircaloy-2 pressure tube material

International Nuclear Information System (INIS)

Srivastava, D.; Tewari, R.; Dey, G.K.; Sharma, B.P.; Sah, D.N.; Banerjee, Suparna; Sahoo, K.C.

2005-09-01

In the present work, microstructure of the zircaloy-2 pressure tube material irradiated in the Indian Pressurized Heavy Water RAPP-1. Reactor (PHWR) has been examined for the first time using transmission electron microscope (TEM). The samples were obtained 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) and expected to have a cumulative radiation damage of about 3 dpa. In this study irradiated microstructure has been characterized and compared it with the microstructure of the unirradiated pressure tube samples. The effect of irradiation on the hydriding behaviour is also studied. (author)

Microstructural characterization and model of hardening for the irradiated austenitic stainless steels of the internals of pressurized water reactors; Caracterisation microstructurale et modelisation du durcissement des aciers austenitiques irradies des structures internes des reacteurs a eau pressurisee

Energy Technology Data Exchange (ETDEWEB)

Pokor, C

2003-07-01

The core internals of Pressurized Water Reactors (PWR) are composed of SA 304 stainless steel plates and CW 316 stainless steel bolts. These internals undergo a neutron flux at a temperature between 280 deg C and 380 deg C which modifies their mechanical properties. These modifications are due to the changes in the microstructure of these materials under irradiation which depend on flux, dose and irradiation temperature. We have studied, by Transmission Electron Microscopy, the microstructure of stainless steels SA 304, CW 316 and CW 316Ti irradiated in a mixed flux reactor (OSIRIS at 330 deg C between 0,8 dpa et 3,4 dpa) and in a fast breeder reactor at 330 deg C (BOR-60) up to doses of 40 dpa. Moreover, samples have been irradiated at 375 deg C in a fast breeder reactor (EBR-II) up to doses of 10 dpa. The microstructure of the irradiated stainless steels consists in faulted Frank dislocation loops in the [111] planes of austenitic, with a Burgers vector of [111]. It is possible to find some voids in the solution annealed samples irradiated at 375 deg C. The evolution of the dislocations loops and voids has been simulated with a 'cluster dynamic' model. The fit of the model parameters has allowed us to have a quantitative description of our experimental results. This description of the microstructure after irradiation was coupled together with a hardening model by Frank loops that has permitted us to make a quantitative description of the hardening of SA 304, CW 316 and CW 316Ti stainless steels after irradiation at a certain dose, flux and temperature. The irradiation doses studied grow up to 90 dpa, dose of the end of life of PWR internals. (author)

UMTRA project water sampling and analysis plan, Naturita, Colorado

International Nuclear Information System (INIS)

1994-04-01

Surface remedial action is scheduled to begin at the Naturita UMTRA Project processing site in the spring of 1994. No water sampling was performed during 1993 at either the Naturita processing site (NAT-01) or the Dry Flats disposal site (NAT-12). Results of previous water sampling at the Naturita processing site indicate that ground water in the alluvium is contaminated as a result of uranium processing activities. Baseline ground water conditions have been established in the uppermost aquifer at the Dry Flats disposal site. Water sampling activities scheduled for April 1994 include preconstruction sampling of selected monitor wells at the processing site, surface water sampling of the San Miguel River, sampling of several springs/seeps in the vicinity of the disposal site, and sampling of two monitor wells in Coke Oven Valley. The monitor well locations provide sampling points to characterize ground water quality and flow conditions in the vicinity of the sites. The list of analytes has been updated to reflect constituents related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted annually at minimum during the period of construction activities

Study on the behavior of irradiated light water reactor fuel during out-of-pile annealing

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki; Kanazawa, Hiroyuki; Uno, Hisao; Sasajima, Hideo

1988-11-01

Using the pre-irradiated light water reactor fuel (burnup: 35 MWd/kgU) and the slightly irradiated NSRR fuel (burnup: 5.6 x 10 -6 MWd/kgU), FP gas release rate up to the temperature of 2273 K was measured through out-of-pile annealing test. Results of this experiment were compared with those of ORNL annealing test (SFD/HI-test series) performed in USA. Obtained conclusions are: (1) Maximum release rate of Kr gas in light water reactor fuel was 6.4 % min -1 at temperature of 2273 K. This was in good agreement with ORNL data. FP gas release rate during annealing test was increased greatly with increasing fuel burnup and annealing temperature. (2) No FP was detected in NSRR slightly irradiated fuel up to the temperature of 1913 K. (author)

Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

Science.gov (United States)

Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

2018-03-01

With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

Irradiation and germination effects on phytate, protein and amino acids of soybean

International Nuclear Information System (INIS)

Sattar, A.; Neelofar; Akhtar, M.A.

1990-01-01

Influence of irradiation (0.05–0.20 kGy) and germination (24–120 hours) in distilled and tap water on phytate, protein and amino acids of soybean, was studied. Phytate values significantly decreased with increasing germination period and irradiation dose (P<0.01). Irradiation independently decreased the original phytate (212.0 mg/100 g) to a range value of 205.0–190.0 mg/100 g depending upon dose level. Germination of unirradiated seeds for 120 hours in distilled and tap water lowered the phytate to 55.0 and 94.9 mg/100 g (74.1 and 55.2% reduction) respectively. Maximum destruction of phytate to levels of 20.5 and 50.9 mg/100 g (90.3 and 76.0% reduction) occurred during germination of 0.20 kGy samples for 120 hours in distilled and tap water respectively. Total protein content significantly increased during germination (P<0.05) and the increase was more in tap than distilled water. Germination for 120 hours of untreated seeds in tap water increased the essential and decreased non-essential amino acids while in the 0.10 kGy sample, increases in both cases were observed

The digestibility of gamma-irradiated bovine serum albumin solution with thermolysin

International Nuclear Information System (INIS)

Hattori, Yukihiko

1981-01-01

Samples of bovine serum albumin (BSA) (fatty acid free, fraction V, purchased from Miles Laboratories Inc.) solution (in triply distilled water) were irradiated with 60 Co γ-rays in Pyrex tubes in the presence of air at room temperature. Taking the practical conditions of food irradiation into consideration, the concentration of BSA solution ranged from 0.6 to 9.6%, and the dose ranged from 5 to 15 kGy. Irradiated BSA solutions were subjected to the assay of proteolytic digestibility with thermolysin. The result indicates that all irradiated samples had larger digestibility with thermolysin than unirradiated control. Within the dose range of the experiment, the largest digestibility values for the irradiated samples of 0.6, 1.2, 2.4, 4.8 and 9.6% were 2.7, 2.5, 2.5, 2.3, and 1.9 times as large as that of unirradiated control, respectively. In the case of 0.6% solution the digestibility showed its maximum at 5 kGy, and at the higher doses (10 and 15 kGy) it decreased linearly. The irradiated BSA solutions of 1.2% or higher concentrations did not reveal such decrease in the digestibility. The results of analyses of amino acid composition and ultracentrifugal sedimentation pattern suggest that the decrease in the digestibility in the case of 0.6% solution can be attributed to the modification of amino acid residues, crosslinking and aggregation of BSA molecules. Furthermore, it is mentioned that the digestibility with thermolysin will be a possible measure for the denaturation of water containing protein irradiated with practical dose for the food irradiation. (J.P.N.)

Advances in Radiocarbon Measurement of Water Samples

Energy Technology Data Exchange (ETDEWEB)

Janovics, R.; Molnar, M.; Major, I. [Institute of Nuclear Research (ATO MKI), Hungarian Academy of Sciences, H-4001 Debrecen (Hungary); Svetlik, I. [Department of Radiation Dosimetry, Nuclear Physics Institute AS CR, Prague (Czech Republic); Wacker, L. [Institute for Particle Physics, ETH Hoenggerberg, Zuerich (Switzerland)

2013-07-15

In this paper two very different and novel methods for the {sup 14}C measurement of water samples are presented. The first method uses direct absorption into a scintillation cocktail and a following liquid scintillation measurement. Typical sample size is 20-40 L and overall uncertainty is {+-} 2% for modern samples. It is a very cost effective and easy to use method based on a novel and simple static absorption process for the CO{sub 2} extracted from groundwater. The other very sensitive method is based on accelerator mass spectrometry (AMS) using a gas ion source. With a MICADAS type AMS system we demonstrated that you can routinely measure the {sup 14}C content of 1 mL of water sample with better than 1% precision (for a modern sample). This direct {sup 14}C AMS measurement of water takes less than 20 minutes including sample preparation. (author)

The effects of gamma irradiation on the leaching of reducing sugars, inorganic phosphate and enzymes from barley seeds during germination in water

International Nuclear Information System (INIS)

Kurobane, I.; Yamaguchi, H.; Sander, C.; Nilan, R.A.

1979-01-01

Gamma irradiation enhanced the leaching of reducing sugars from barley seeds into the water in which the seeds were shaken. Treatments prior to shaking in water, such as overnight soaking in water at 5 0 C and subsequent germination in Petri dishes for 1 or 2 days at 20 0 C, showed pronounced effects on the leaching. The highest effect, which was obtained at 500 krad irradiation, was four times higher than that of the non-irradiated control. Gamma irradiation also stimulated the leaching of inorganic phosphate and slightly that of amylases from barley seeds. When seeds from which the embryos has been removed were shaken into water, no stimulating effect on the leaching of sugars was noted. These results, combined with the irradiation effect on the embryo, suggest that the stimulated leaching of reducing sugars is due to the extreme difference in sensitivity to gamma irradiation between the production of reducing sugars in the endosperm and the development and growth of the embryo. (author)

Gamma-irradiation synthesis of silver nanoparticles fixing in porous ceramic for application in water treatment

International Nuclear Information System (INIS)

Dang Van Phu; Nguyen Quoc Hien; Nguyen Thuy Ai Trinh; Bui Duy Du

2013-01-01

The Ag nanoparticles in polyvinylpyrrolidone solution with concentration of 500 mg/L and their diameter of 10-15 nm were synthesized on a large scale up to 100 L/batch by gamma irradiation route. Porous ceramic candle samples were functionalized by treatment with a 3-amino-propyltriethoxysilane coupling agent and then impregnated in Ag nanoparticles solution for fixing Ag nanoparticles. The load Ag nanoparticles content on porous ceramic was of about 200-250 mg/kg. The average pore size of porous ceramic/Ag nanoparticles was about 48.2 Å. Owing to strong bonding of silver atoms to the wall of porous ceramic functionalized by 3-amino-propyltriethoxysilane, the contents of silver released from porous ceramic/Ag nanoparticles into filtrated water by test at a flow rate of about 5 L/h were less than 10 μg/L and was far below the required standard limit (<100 μg/L) for drinking water. Thus, porous ceramic/Ag nanoparticles candles can be potentially applied for point-of-use drinking water treatment. (author)

UMTRA project water sampling and analysis plan, Gunnison, Colorado

International Nuclear Information System (INIS)

1994-06-01

This water sampling and analysis plan summarizes the results of previous water sampling activities and the plan for water sampling activities for calendar year 1994. A buffer zone monitoring plan is included as an appendix. The buffer zone monitoring plan is designed to protect the public from residual contamination that entered the ground water as a result of former milling operations. Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually in 1994 at the Gunnison processing site (GUN-01) and disposal site (GUN-08). Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer (Tertiary gravels) at the Gunnison disposal site. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted at least semiannually during and one year following the period of construction activities, to comply with the ground water protection strategy discussed in the remedial action plan (DOE, 1992a)

Gas-driven pump for ground-water samples

Science.gov (United States)

Signor, Donald C.

1978-01-01

Observation wells installed for artificial-recharge research and other wells used in different ground-water programs are frequently cased with small-diameter steel pipe. To obtain samples from these small-diameter wells in order to monitor water quality, and to calibrate solute-transport models, a small-diameter pump with unique operating characteristics is required that causes a minimum alternation of samples during field sampling. A small-diameter gas-driven pump was designed and built to obtain water samples from wells of two-inch diameter or larger. The pump is a double-piston type with the following characteristics: (1) The water sample is isolated from the operating gas, (2) no source of electricity is ncessary, (3) operation is continuous, (4) use of compressed gas is efficient, and (5) operation is reliable over extended periods of time. Principles of operation, actual operation techniques, gas-use analyses and operating experience are described. Complete working drawings and a component list are included. Recent modifications and pump construction for high-pressure applications also are described. (Woodard-USGS)

Effect of gamma irradiation on physicochemical properties of stored pigeon pea (Cajanus cajan) flour.

Science.gov (United States)

Bamidele, Oluwaseun P; Akanbi, Charles T

2013-09-01

The effect of gamma irradiation at various doses (5, 10, 15, 20 kGy) was observed on pigeon pea flour stored for 3 months on proximate composition, functional properties, and peroxide value. Sensory evaluation was also carried out on bean cake (moinmoin) made from nonirradiated and irradiated pigeon pea flour. The results showed that stored gamma-irradiated samples had significantly lower (P flours showed slight increase in water absorption capacity, swelling capacity and bulk density. The peroxide value of crude oil increased significantly with dose increases for the period of storage. The sensory evaluation of moinmoin samples prepared from irradiated pigeon pea flour showed no significant difference from the moinmoin sample prepared from nonirradiated flour. It can be concluded that gamma irradiation can extend the shelf life of pigeon pea flour.

The application of irradiation techniques to food and foodstuffs

International Nuclear Information System (INIS)

Kwon, Joong Ho; Cho, Han Ok; Byun, Myung Woo; Kim, Suck Won; Yang, Jae Seung

1993-01-01

With a view to establishing concrete infrastructures for the enlarged utilization of irradiation techniques in the food industries, the efficacy of gamma irradiation was investigated for both soybeans having problems in water-soaking process before mass-processing and dried-red pepper requiring long-term storage. Irradiation of 5 kGy was found effective for the reduction of soaking and cooking time of soybeans, but negligible changes were induced by irradiation in their nutritional components and processing properties (Tofu,soymilk). Air-tight packaging was suitable for the keeping quality of dried red pepper and irradiation applications were more effective in powdered samples than in whole pepper for preserving and improving their quality. (Author)

Analysis of gamma irradiated pepper constituents, 5

International Nuclear Information System (INIS)

Takagi, Kazuko; Okuyama, Tsuneo; Ishikawa, Toshihiro.

1988-01-01

Gamma irradiated peppers (10 krad, 100 krad, 1 Mrad) were analyzed by HPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C 8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile-0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. It is difficult to compare with irradiated and unirradiated pepper constituents by their peak height or area. And the method of multi variant statistically analysis was introduced. The 'peak n area/peak n + 1 area' ratio was calculated by computer. Each peak area was accounted by integrator. The value of these ratio were called 'parameter'. Each chromatogram has 741 parameters calculated with 39 chromatographic peaks. And these parameters were abopted to the multi variant statiscally analysis. Comparison of constituents between irradiated pepper and unirradiated pepper was done by 741 parameters. The correlation of parameters between irradiated and unirradiated was investigated by use of computer. Some parameters of irradiated case were selected as which had no correlation with unirradiated case. That is to say these parameters were thought to be changed with gamma spectrum irradiation. By this method, Coumarin was identified as a changed component with gamma irradiation. (author)

Use of TRIGA flip fuel for improved in-core irradiations

Energy Technology Data Exchange (ETDEWEB)

Whittemore, W L [General Atomic Co., San Diego, CA (United States)

1974-07-01

Use of standard TRIGA fuel (20% enriched uranium) in a reactor provides a suitable facility for in-core irradiations. However, large numbers of in-core samples irradiated for long periods (many months) can be handled more economically with a TRIGA loaded with FLIP fuel. As an example, ten or more in-core thermionic devices (each worth 50 to 80 cents with respect to a water-filled position) were irradiated in the Mark III TRIGA at General Atomic Company for 18 months with only a modest change in excess reactivity due to core burnup. A core loading of FLIP fuel has been added to the General Atomic Mark F reactor in order to provide numerous in-core irradiation sites for the production of radioisotopes. Since the worth of a 500-gram sample of a molybdenum compound (used for the production of {sup 99}Mo) is about 25 to 50 cents with respect to a water-filled position, use of a FLIP- TRIGA core will permit the irradiation of more than 5 kilograms of a molybdenum compound. A procedure is under development for the production of {sup 99}Mo with relatively high specific activity. Several techniques to concentrate {sup 99}Mo have been tested experimentally. The results will be reported. (author)

Fuel fabrication and post-irradiation examination

Energy Technology Data Exchange (ETDEWEB)

Venter, P J; Aspeling, J C [Atomic Energy Corporation of South Africa Ltd., Pretoria (South Africa)

1990-06-01

This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

Fuel fabrication and post-irradiation examination

International Nuclear Information System (INIS)

Venter, P.J.; Aspeling, J.C.

1990-01-01

This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

Radon in water samples around Ningyo Toge area

Energy Technology Data Exchange (ETDEWEB)

Furuta, Sadaaki [Power Reactor and Nuclear Fuel Development Corp., Kamisaibara, Okayama (Japan). Ningyo Toge Works

1997-02-01

Radon concentrations of river water and drinking water were surveyed. Water samples were collected from the region around Ningyo-Toge Works which were positioned on a granitic layer having uranium deposit. Each sample was taken using a separating funnel and the radioactivity was counted by liquid scintillation counter (ALOKA, LB-2). Since there were old working places of mine in the region, mine drainages from them were also analyzed. The radon concentration of drinking water from the region ranged from 0.1 to 230 Bq/l. The samples with a higher activity than 100 Bq/l were water from springs or wells and the area of the highest Rn concentration was on a typical granitic layer, suggesting some geographic effects on Rn concentration. Some samples of drinking water had slightly higher levels of Rn, probably due to the utilization of underflow as its source. The mean concentration of Rn became higher in the order; river water, drinking water, mine drainage in the region. In addition, a negative correlation between Rn concentration of water and the river flow rate was observed in this region. (M.N.)

Water sample-collection and distribution system

Science.gov (United States)

Brooks, R. R.

1978-01-01

Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

The analysis and attribution of the time-dependent neutron background resultant from sample irradiation in a SLOWPOKE-2 reactor

International Nuclear Information System (INIS)

Sellers, M.T.; Corcoran, E.C.; Kelly, D.G.

2013-01-01

The Royal Military College of Canada (RMCC) has commissioned a Delayed Neutron Counting (DNC) system for the analysis of special nuclear materials. A significant, time-dependent neutron background with an initial maximum count rate, more than 50 times that of the time-independent background, was characterised during the validation of this system. This time-dependent background was found to be dependent on the presence of the polyethylene (PE) vials used to transport the fissile samples, yet was not an activation product of vial impurities. The magnitude of the time-dependent background was found to be irradiation site specific and independent of the mass of PE. The capability of RMCC's DNC system to analyze the neutron count rates in time intervals 235 U contamination was present on each irradiated vial. However, Inductively Coupled Plasma-Mass Spectroscopy measurements of material leached from the outer vial surfaces after their irradiations found only trace amounts of uranium, 0.118 ± 0.048 ng of 235 U derived from natural uranium. These quantities are insufficient to account for the time-independent background, and in fact could not be discriminated from the noise associated with time-independent background. It is suggested that delayed neutron emitters are deposited in the vial surface following fission recoil, leaving the main body of uranium within the irradiation site. This hypothesis is supported by the physical cleaning of the site with materials soaked in distilled water and HNO 3 , which lowered the background from a nominal 235 U mass equivalent of 120 to 50 ng per vial. (author)

The reaction of unirradiated and irradiated nuclear graphites with water vapor in helium

International Nuclear Information System (INIS)

Imai, Hisashi; Nomura, Shinzo; Kurosawa, Takeshi; Fujii, Kimio; Sasaki, Yasuichi

1980-10-01

Nuclear graphites more than 10 brands were oxidized with water vapor in helium and then some selected graphites were irradiated with fast neutron in the Japan Materials Testing Reactor to clarify the effect of radiation damage of graphite on their reaction behaviors. The reaction was carried out under a well defined condition in the temperature range 800 -- 1000 0 C at concentrations of water vapor 0.38 -- 1.30 volume percent in helium flow of total pressure of 1 atm. The chemical reactivity of graphite irradiated at 1000 +- 50 0 C increased linearly with neutron fluence until irradiation of 3.2 x 10 21 n/cm 2 . The activation energy for the reaction was found to decrease with neutron fluence for almost all the graphites, except for a few ones. The order of reaction increased from 0.5 for the unirradiated graphite to 1.0 for the graphite irradiated up to 6.0 x 10 20 n/cm 2 . Experiment was also performed to study a superposed effect between the influence of radiation damage of graphite and the catalytic action of barium on the reaction rate, as well as the effect of catalyser of barium. It was shown that these effects were not superposed upon each other, although barium had a strong catalytic action on the reaction. (author)

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.

Quality-control design for surface-water sampling in the National Water-Quality Network

Science.gov (United States)

Riskin, Melissa L.; Reutter, David C.; Martin, Jeffrey D.; Mueller, David K.

2018-04-10

The data-quality objectives for samples collected at surface-water sites in the National Water-Quality Network include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of environmental conditions. Quality-control samples provide insight into how well the samples collected at surface-water sites represent the true environmental conditions. Quality-control samples used in this program include field blanks, replicates, and field matrix spikes. This report describes the design for collection of these quality-control samples and the data management needed to properly identify these samples in the U.S. Geological Survey’s national database.

Effects of gamma irradiation on deteriorated paper

Science.gov (United States)

Bicchieri, Marina; Monti, Michela; Piantanida, Giovanna; Sodo, Armida

2016-08-01

Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State (http://www.icpal.beniculturali.it/allegati/DM-7

The WIPP Water Quality Sampling Program

International Nuclear Information System (INIS)

Uhland, D.; Morse, J.G.; Colton, D.

1986-01-01

The Waste Isolation Pilot Plant (WIPP), a Department of Energy facility, will be used for the underground disposal of wastes. The Water Quality Sampling Program (WQSP) is designed to obtain representative and reproducible water samples to depict accurate water composition data for characterization and monitoring programs in the vicinity of the WIPP. The WQSP is designed to input data into four major programs for the WIPP project: Geochemical Site Characterization, Radiological Baseline, Environmental Baseline, and Performance Assessment. The water-bearing units of interest are the Culebra and Magneta Dolomite Members of the Rustler Formation, units in the Dewey Lake Redbeds, and the Bell Canyon Formation. At least two chemically distinct types of water occur in the Culebra, one being a sodium/potassium chloride water and the other being a calcium/magnesium sulfate water. Water from the Culebra wells to the south of the WIPP site is distinctly fresher and tends to be of the calcium/magnesium sulfate type. Water in the Culebra in the north and around the WIPP site is distinctly fresher and tends to be of the sodium/potassium chloride type and is much higher in total dissolved solids. The program, which is currently 1 year old, will continue throughout the life of the facility as part of the Environmental Monitoring Program

Validation of single-sample doubly labeled water method

International Nuclear Information System (INIS)

Webster, M.D.; Weathers, W.W.

1989-01-01

We have experimentally validated a single-sample variant of the doubly labeled water method for measuring metabolic rate and water turnover in a very small passerine bird, the verdin (Auriparus flaviceps). We measured CO 2 production using the Haldane gravimetric technique and compared these values with estimates derived from isotopic data. Doubly labeled water results based on the one-sample calculations differed from Haldane values by less than 0.5% on average (range -8.3 to 11.2%, n = 9). Water flux computed by the single-sample method differed by -1.5% on average from results for the same birds based on the standard, two-sample technique (range -13.7 to 2.0%, n = 9)

Determination of uranium in industrial and environmental samples. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

El-Sweify, F H; Shehata, M K; Metwally, E M; El-Shazly, E A.A.; El-Naggar, H A [Nuclear Chemistry Department, Hot Laborities Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

The phosphate ores used at `Abu zaabal fertilizer and chemical company` for the production of some chemicals and fertilizers contain detectable amounts of uranium. In this study, the content of uranium in samples of different products of fertilizers, gypsum, and phosphate ore were determined using NAA, and gamma ray spectroscopy of the irradiated samples. Another method based on measuring the natural radioactivity of {sup 238} U series for non-irradiated samples using gamma-ray spectroscopy was also used for determine uranium content in the samples. In the NAA method, the content of U(ppm) in the samples was been computed from the photopeak activity of the lines = 106.1, 228.2, and 277.5 KeV of {sup 239} Np induced in the irradiated samples, and the uranium standard simultaneously irradiated. the gamma-ray spectra, and the decay curves are given. In the second method the gamma-ray spectra of the natural radioactivity of the samples and uranium standard were measured. The gamma-transition of energies 295.1, 251.9 KeV for {sup 214} Pb; 609.3, 768.4, 1120.3, 1238.1 KeV for {sup 214} Bi were determined. The uranium {sup 23U} traces in drainage water was also determined spectrophotometrically using arsenazo-III after preconcentration of uranium from the pretreated drainage water in column packed with chelex-100 resin. The recovery was found to be 90 {+-} 5%. 11 figs., 3 tabs.

Toxicity reduction for pharmaceuticals mixture in water by electron beam irradiation

International Nuclear Information System (INIS)

Boiani, Nathalia Fonseca; Tominaga, Flavio Kiyoshi; Borrely, Sueli Ivone

2015-01-01

The incorrect disposal of products is committing the environment quality once the aquatic environment is the main vehicle for dispersion of pollutants. Among the highlighted contaminants there are the pharmaceuticals, which are also released to the aquatic environment through the domestic sewage, hospitals and effluents. The monitoring of these pharmaceuticals in the environment has grown, showing many of them as persistent pollutants. Pharmaceuticals from different therapeutic classes have been detected in domestic sewage, surface water and groundwater around the world. Several studies evidenced Fluoxetine Hydrochloride residues in waters. Another important product is the Propranolol, used for heart disease treatments as far as fluoxetine is applied for treating mental diseases. The objective of this study was to apply the radiation processing for the abatement of pollutant in waters. Electron beam accelerator was used during irradiation of the mixture (Propranolol + Fluoxetine Hydrochloride) in aqueous solution. Acute toxicity assays were carried out for Vibrio fischeri marine bacterium, 15 minutes exposure. The results showed that irradiation (2.5kGy and 5.0kGy) enhanced the average effective concentration of the mixture, which means reduction of toxicity (56.34%, 55.70% respectively). Inverse effect was obtained with 7.5 kGy and 10 kGy. (author)

Toxicity reduction for pharmaceuticals mixture in water by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Boiani, Nathalia Fonseca; Tominaga, Flavio Kiyoshi; Borrely, Sueli Ivone, E-mail: flavio_tominaga@hotmail.com, E-mail: sborrely@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The incorrect disposal of products is committing the environment quality once the aquatic environment is the main vehicle for dispersion of pollutants. Among the highlighted contaminants there are the pharmaceuticals, which are also released to the aquatic environment through the domestic sewage, hospitals and effluents. The monitoring of these pharmaceuticals in the environment has grown, showing many of them as persistent pollutants. Pharmaceuticals from different therapeutic classes have been detected in domestic sewage, surface water and groundwater around the world. Several studies evidenced Fluoxetine Hydrochloride residues in waters. Another important product is the Propranolol, used for heart disease treatments as far as fluoxetine is applied for treating mental diseases. The objective of this study was to apply the radiation processing for the abatement of pollutant in waters. Electron beam accelerator was used during irradiation of the mixture (Propranolol + Fluoxetine Hydrochloride) in aqueous solution. Acute toxicity assays were carried out for Vibrio fischeri marine bacterium, 15 minutes exposure. The results showed that irradiation (2.5kGy and 5.0kGy) enhanced the average effective concentration of the mixture, which means reduction of toxicity (56.34%, 55.70% respectively). Inverse effect was obtained with 7.5 kGy and 10 kGy. (author)

Evolution of the Marginal Ice Zone: Adaptive Sampling with Autonomous Gliders

Science.gov (United States)

2015-09-30

release; distribution is unlimited. Evolution of the Marginal Ice Zone: Adaptive Sampling with Autonomous Gliders Craig M. Lee, Luc Rainville and Jason I...missions in ice-covered waters , where they provide several unique capabilities. Ice-capable Seagliders can maintain persistent (many months) sampling ...irradiance. Careful calibration casts, including water sampling , were conducted during both the deployment and recovery cruises. An example of a

Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials

International Nuclear Information System (INIS)

Nanstad, R.K.; Corwin, W.R.; Alexander, D.J.; Haggag, F.M.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.; Stoller, R.E.

1995-01-01

The safety of commercial light-water nuclear plants is highly dependent on the structural integrity of the reactor pressure vessel (RPV). In the absence of radiation damage to the RPV, fracture of the vessel is difficult to postulate. Exposure to high energy neutrons can result in embrittlement of radiation-sensitive RPV materials. The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory, sponsored by the US Nuclear Regulatory Commission (USNRC), is assessing the effects of neutron irradiation on RPV material behavior, especially fracture toughness. The results of these and other studies are used by the USNRC in the evaluation of RPV integrity and regulation of overall nuclear plant safety. In assessing the effects of irradiation, prototypic RPV materials are characterized in the unirradiated condition and exposed to radiation under varying conditions. Mechanical property tests are conducted to provide data which can be used in the development of guidelines for structural integrity evaluations, while metallurgical examinations and mechanistic modeling are performed to improve understanding of the mechanisms responsible for embrittlement. The results of these investigations, in conjunction with results from commercial reactor surveillance programs, are used to develop a methodology for the prediction of radiation effects on RPV materials. This irradiation-induced degradation of the materials can be mitigated by thermal annealing, i.e., heating the RPV to a temperature above that of normal operation. Thus, thermal annealing and evaluation of reirradiation behavior are major tasks of the HSSI Program. This paper describes the HSSI Program activities by summarizing some past and recent results, as well as current and planned studies. 30 refs., 8 figs., 1 tab

Determinação voltamétrica de metais em águas e fluidos biológicos empregando mineralização de amostras com radiação ultravioleta Voltammetric determination of metals in waters and biological fluids using sample mineralization with ultraviolet radiation

Directory of Open Access Journals (Sweden)

Leandro M. de Carvalho

2008-01-01

Full Text Available This work describes the optimization of pretreatment steps for the destruction of organic matter in samples of waters and biological fluids, by using an UV irradiation system with a high power UV radiation source (400 W. The efficiency of the system constructed for the photo-decomposition of samples of model waters, natural waters and biological fluids was investigated by performing recovery experiments of the metallic species Zn(II, Cd(II, Pb(II, Cu(II, Al(III and Fe(III. The use of UV irradiation allowed the liberation of metals bound to the organic matrix and the determination of the total content of elements in the samples.

Disinfection of contaminated water by using solar irradiation.

Science.gov (United States)

Caslake, Laurie F; Connolly, Daniel J; Menon, Vilas; Duncanson, Catriona M; Rojas, Ricardo; Tavakoli, Javad

2004-02-01

Contaminated water causes an estimated 6 to 60 billion cases of gastrointestinal illness annually. The majority of these cases occur in rural areas of developing nations where the water supply remains polluted and adequate sanitation is unavailable. A portable, low-cost, and low-maintenance solar unit to disinfect unpotable water has been designed and tested. The solar disinfection unit was tested with both river water and partially processed water from two wastewater treatment plants. In less than 30 min in midday sunlight, the unit eradicated more than 4 log10 U (99.99%) of bacteria contained in highly contaminated water samples. The solar disinfection unit has been field tested by Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente in Lima, Peru. At moderate light intensity, the solar disinfection unit was capable of reducing the bacterial load in a controlled contaminated water sample by 4 log10 U and disinfected approximately 1 liter of water in 30 min.

ESR study of the effects of water, methanol, and ethanol on gamma-irradiation of starch

International Nuclear Information System (INIS)

Henderson, A.M.; Rudin, A.

1981-01-01

This investigation deals with the nature and relative abundance of stable radicals formed by gamma-irradiation of wheat starch at room temperature. Additions of equal weights of water, methanol, and ethanol were equally effective in reducing the content of stable radicals in starch which contained about 12% water before the additions. When, however, the starting material was dried starch with 2.9% initial water content additional water and methanol were better radical scavengers than ethanol. This difference is attributed to the superior ability of water and methanol to permeate the starch structure. Superficially different ESR spectra were obtained in products made by irradiating starch and starch that contained added water or methanol. Computer simulation of these spectra showed that they could be matched by superposition of the spectra of the same four component radicals, with some adjustments of relative intensities and peak widths. The structure of these radicals have been deduced from the spectral assignments and relative effects of the three solvents used on the intensities of the respective ESR spectra

Thermoluminescence method for detection of irradiated food

International Nuclear Information System (INIS)

Pinnioja, S.

1998-01-01

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

Thermoluminescence method for detection of irradiated food

Energy Technology Data Exchange (ETDEWEB)

Pinnioja, S

1998-12-31

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

The effect of fission-energy Xe ion irradiation on the structural integrity and dissolution of the CeO{sub 2} matrix

Energy Technology Data Exchange (ETDEWEB)

Popel, A.J., E-mail: apopel@cantab.net [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ (United Kingdom); Department of Materials, Imperial College London, London, SW7 2AZ (United Kingdom); Le Solliec, S.; Lampronti, G.I.; Day, J. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ (United Kingdom); Petrov, P.K. [Department of Materials and London Centre for Nanotechnology, Imperial College London, London, SW7 2AZ (United Kingdom); Farnan, I. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ (United Kingdom)

2017-02-15

This work considers the effect of fission fragment damage on the structural integrity and dissolution of the CeO{sub 2} matrix in water, as a simulant for the UO{sub 2} matrix of spent nuclear fuel. For this purpose, thin films of CeO{sub 2} on Si substrates were produced and irradiated by 92 MeV {sup 129}Xe{sup 23+} ions to a fluence of 4.8 × 10{sup 15} ions/cm{sup 2} to simulate fission damage that occurs within nuclear fuels along with bulk CeO{sub 2} samples. The irradiated and unirradiated samples were characterised and a static batch dissolution experiment was conducted to study the effect of the induced irradiation damage on dissolution of the CeO{sub 2} matrix. Complex restructuring took place in the irradiated films and the irradiated samples showed an increase in the amount of dissolved cerium, as compared to the corresponding unirradiated samples. Secondary phases were also observed on the surface of the irradiated CeO{sub 2} films after the dissolution experiment. - Highlights: • Ion irradiation induced microstructural rearrangements in CeO{sub 2} thin films. • Ion irradiation reduced aqueous durability of bulk and thin film CeO{sub 2} samples. • Secondary phases observed from dissolution of irradiated CeO{sub 2} films in di-water.

Thermoluminescence study of Cu and Ag doped lithium tetraborate samples synthesized by water/solution assisted method

Energy Technology Data Exchange (ETDEWEB)

Thiyagarajan, S.; Kumar, S.; Vallejo, M.; Sosa, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, 37150 Leon, Guanajuato (Mexico); Velusamy, J., E-mail: thiya93@gmail.com [Centro de Investigaciones en Optica, Apdo. Postal 1-948, Leon, Guanajuato (Mexico)

2016-10-15

In this paper lithium tetraborate (Li{sub 2}B{sub 4}O{sub 7}) was produced by water/solution assisted synthesis method. Transition metals, such as Cu and Ag were used to dope Li{sub 2}B{sub 4}O{sub 7} in order to enhance its thermoluminescent properties. The heating temperature parameters for synthesis were 750 degrees Celsius for 2 hours and 150 degrees Celsius for another 2 hours. The samples produced by water assisted method were doped at different doping percentage (0.08, 0.12, 0.5, 0.1 and 1%) of Cu and Ag. Pellets of samples were prepared and there were irradiated with different doses (58, 100, 500 and 945 mGy) by using and X-ray source. The characteristics of undoped and doped Li{sub 2}B-4O{sub 7} were determined by X-ray diffraction (XRD), scanning electron microscopy (Sem), photoluminescence and ultraviolet-visible spectroscopy. The chemical composition and their morphologies of the obtained Li{sub 2}B{sub 4}O{sub 7} and Li{sub 2}B{sub 4}O{sub 7}:Cu, Ag was confirmed by XRD and Sem results. The most intense peak of the XRD pattern of the lithium tetraborate sample was determined by comparing to the reference data and was found to have a tetragonal structure. The thermoluminescent glow curves of the pellets exposed to different doses exhibited a clear response to X-ray irradiation. Especially Li{sub 2}B{sub 4}O{sub 7}:Cu presented a good glow curve in all kind of doses. The experimental results showed that this could have good potential applications in radiation dosimetry. The order of kinetics (b), frequency factor (s) and activation energy (E) or the trapping parameters were calculated using peak shape method. (Author)

AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl

NARCIS (Netherlands)

Gaynutdinov, R; Vainshtein, DI; Hak, SJ; Tolstikhina, A; Den Hartog, HW

2003-01-01

AFM investigations are reported for heavily, electron irradiated NaCl crystals in ultra high vacuum (UHV) in the non-contact mode-with an UHV AFM/STM Omicron system. To avoid chemical reactions between the radiolytic Na and oxygen and water, the irradiated samples were cleaved and prepared for the

Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

International Nuclear Information System (INIS)

Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

1987-01-01

Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

Specifics of adsorption and chemical processes on the surface of gamma-irradiated vanadium dioxide

International Nuclear Information System (INIS)

Kaurkovskaya, V.N.; Dzyubenko, L.S.; Doroshenko, V.N.; Chujko, A.A.; Shakhov, A.P.

2006-01-01

Effect of γ-irradiation on electrophysical properties and processes of thermal desorption of water from the surface of vanadium oxides V 2 O 3 -VO 2-δ -VO 2+δ -V 2 O 5 was investigated by derivatography and electric conductivity. Content of adsorbed water at the surface and phase composition of the surface was demonstrated to change under the action of low radiation doses. Surface electric conductivity of the irradiated samples VO 2-δ in the process of chemical reactions of adsorbed following irradiation benzoic acid and ethanol was established to be much above than in irradiated-free ones. It is presumed that metal-semiconductor phase transition at the surface of VO 2-δ during chemical reaction is intensified by irradiation [ru

Irradiation and corrosion behaviour of cadmium aluminate, a burnable poison for light water reactors

International Nuclear Information System (INIS)

Hattenbach, K.; Ahlf, J.; Hilgendorff, W.; Zimmermann, H.U.

1979-01-01

In quest of a cadmium containing material for use as burnable poison cadmium aluminate seemed promising. Therefore irradiation and corrosion experiments on specimens of cadmium aluminate in a matrix of aluminia were performed. Irradiation at 575 K and fast fluences up to 10 25 m -2 showed the material to have good radiation resistance and low swelling rates. Cadmium pluminate was resistant to corrosion attack in demineralized water of 575K. (orig.) [de

Antioxidant activity of extract from gamma irradiated red grape (Vitis vinifera) seeds

International Nuclear Information System (INIS)

Abdeldaiem, M. H.; Ali, H.G.M.; Nasr, E.H.

2012-01-01

This investigation aims to study the antioxidant activity efficiency of extracts from irradiated defatted red grape seeds at dose levels of 1, 3 and 5 kGy). The non-irradiated and irradiated defatted red grape seeds samples were extracted with acetone: water: acetic acid (90:9.5:0.5) immediately after irradiation and the antioxidant activity were studied. Gas chromatographic-Mass spectrum was applied to identify and quantify the phenolic compounds of extracts and the amino acids composition was determined in all samples under investigation of defatted red grape seeds. The measurements of the antioxidant activity, using a β-carotene-linoleate model system and radical scavenging capacity effect on 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical was determined in the extracts of defatted red grape seeds. The results indicated that extracts of defatted red grape seeds possess marked antioxidant activities, especially control samples compared with irradiated samples. The analysis by GC /MS led to identification of 41, 31, 33 and 28 components the of extract non-irradiated and irradiated samples at doses 1,3 and 5 kGy, respectively. It appears that grape seeds extract could be very effective in inhibiting lipid oxidation of sunflower oil. Thus, according to the results of this study, the extract of defatted red grape seeds may be used as a new potential source of natural antioxidant for food

Effect of combinations of gamma irradiation, hot water, Sodium chloride, and Acetic acid treatments on potato-dry rot

International Nuclear Information System (INIS)

El-Zayat, M.M.; Farahat, A.A.; Saad, N.H.; Shaarawy, N.S.M.

1992-01-01

Gamma irradiation increased the severity of dry rot in potato tubers when they were inoculated with any of 4 species of Fusarium, previously isolated either from irradiated or unirradiated tubers. Treating either irradiated or unirradiated tubers with warm water or sodium chloride solutions following inoculation with F. roseum also increased the severity of dry rot to some extent

Rheology of irradiated honey from Parana region

Energy Technology Data Exchange (ETDEWEB)

Sabato, S.F. E-mail: sfsabato@ipen.br

2004-10-01

Viscosity characteristics can be governed by the molecular chain length of sugars present in the honey. Honey is essentially a mixture of sugar and water. When a physical treatment, as gamma radiation, is applied to food, some changes on its viscosity may occur. Viscosity is one of the important properties of honey and depends on water and sugar quantities. The objective of this work was to verify the rheological behavior of irradiated honey from Parana region in comparison to the unirradiated one. Each rheogram was measured at different shear rates that was increased to a certain value then immediately decreased to the starting point ('up and down curves'). These measurements were made for control and irradiated samples (5 and 10 kGy) in different temperatures (30 deg. C, 35 deg. C and 40 deg. C). The curves constructed with shear stress against shear rate presented linearity. Honey, irradiated and control, showed a Newtonian behavior and gamma radiation did not affect it.

Effect of gamma irradiation on the extraction yield, antioxidant, and antityrosinase activities of pistachio green hull extract

Science.gov (United States)

Abolhasani, Ali; Barzegar, Mohsen; Sahari, Mohammad Ali

2018-03-01

In this study, the antioxidant activity and tyrosinase inhibitory of non-irradiated and irradiated pistachio green hull (PGH) extracts were investigated. After irradiation of PGH by different doses of gamma ray (0, 10, 20, 30 and 40 kGy), their phenolic compounds were extracted by water. Antioxidant activities of extracts were examined by DPPH• and FRAP methods. The results showed that irradiation not only do not have negative effects on antioxidant activity but also it can increase the amount of total phenolic compounds of water extract in comparison with non-irradiated sample. Water extract of irradiated PGH at the dose of 30 kGy, showed the highest antioxidant activity in the DPPH° test with EC50 equal to 289.0 ± 1.2 μg/ml. Irradiated (30 kGy) and non-irradiated water extracts had the highest antityrosinase activities with IC50 of 10.8 ± 1.1 and 11.9 ± 1.2 μg phenolic/ml, respectively. In addition, it was found that the water extract of irradiated PGH can prevent enzymatic browning in sliced raw potatoes. According to the antityrosinase potential of PGH extract, it may be suggested as an antibrowning agent in some foodstuffs or cosmetic products.

Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

Energy Technology Data Exchange (ETDEWEB)

Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Abrecht, David G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Donaldo P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-10-31

Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO₂ from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

Gamma irradiation effects on tofu sold at the market in South of Jakarta region

International Nuclear Information System (INIS)

Idrus Kadir and Harsojo

2009-01-01

Tofu is one of Indonesian traditional food which is popular, well consumed and nutritious. Recent reports pointed out that some distributed tofu had low hygienic quality and contained formaline. Therefore, examination for the formaline content and hygienic quality of tofu sold either at supermarket or traditional market is needed. The purposive sampling method has been used. Samples were taken from locations determined previously. Qualitative test to observe the content of formaline and bacteria were conducted on. Tofu obtained from supermarket and traditional markets at South Jakarta which were irradiated with the dose of 3 kGy. The results showed that all of non-irradiated tofu samples observed content formaline. The total amount of aerobic bacteria in non-irradiated tofu sample were found in the range of 2.2 x 10 5 and 1.4 x 10 7 cfu/g, while for irradiated samples were in the range of 2.5 x 10 2 and 2.0 x 10 4 cfu/g. Coli form bacteria in non-irradiated tofu were in the range of 0 and 7.0 x 10 5 cfu/g, while for irradiated tofu were in the range of 2.5 x 10 2 and 2.2 x 10 3 cfu/g. Total amount of Staphylococcus for non-irradiated tofu samples were found in the range of 0 and 1.3 x 10 6 cfu/g, while for irradiated samples were in the range of 0 and 1.5 x 10 2 cfu/g. None of Salmonella was detected in all tofu samples. The pH of non-irradiated and irradiated tofu was in the range of 5.33 and 5.93, while the water content were in the range of 75.11% and 76.99%. The protein contents of non-irradiated and irradiated tofu were in the range of 7.93% and 8.83% respectively. (author)

Ground-water sample collection and analysis plan for the ground-water surveillance project

International Nuclear Information System (INIS)

Bryce, R.W.; Evans, J.C.; Olsen, K.B.

1991-12-01

The Pacific Northwest Laboratory performs ground-water sampling activities at the US Department of Energy's (DOE's) Hanford Site in support of DOE's environmental surveillance responsibilities. The purpose of this document is to translate DOE's General Environmental Protection Program (DOE Order 5400.1) into a comprehensive ground-water sample collection and analysis plan for the Hanford Site. This sample collection and analysis plan sets forth the environmental surveillance objectives applicable to ground water, identifies the strategy for selecting sample collection locations, and lists the analyses to be performed to meet those objectives

Evaluation of dose exposure from irradiated samples at TRIGA PUSPATI reactor (RTP)

International Nuclear Information System (INIS)

Muhd Husamuddin Abdul Khalil; Julia Abdul Karim; Naim Syauqi Hamzah; Mohamad Hairie Rabir; Mohd Amin Sharifuldin Salleh

2010-01-01

An evaluation has been made to data of irradiated samples for the type of sample requested for activation at RTP. Sample types are grouped with percentage of total throughputs to rule out the weight percent of every respective group. The database consists of radionuclide inventory of short, intermediate and long half-life and high activity radionuclides such as Br and Au have been identified. Evaluation of gamma exposure using Micro shield has also been made to pattern the trend of gamma exposure at experimental facilities and to ensure radiological effect towards safety and health is limited per Radiation Protection (Basic Safety Standard) Regulation 1988. This analysis places an important parameter to improve the design accuracy of shielding design in assuring safety, reliability and economy. (author)

Therapeutic effects of gingerol on hematopoietic and antioxidative damage of 60Co γ-rays irradiated mice

International Nuclear Information System (INIS)

Geng Yanyan; Xie Zhenfei; Zhou Yu; Zeng Xianyin

2012-01-01

18 female Kunming mice were chosen and randomly divided into three groups, and the therapeutic effects of gingerol on hemopoietic and antioxidative system in liver of 60 Co γ-rays irradiated mice were developed in this study. Control group was given distilled water intragastrically once a day for five days. Mice in the irradiated group and irradiated + gingerol group were both irradiated at 3 Gy of 60 Co γ-rays and were given distilled water and gingerol intragastrically within 30 min after irradiation respectively, once a day for five days. The mice were sacrificed and sampled in 48 hours after intragastric administration. Compared with control group, the relative spleen index and WBC numbers significantly decreased (P 60 Co γ-rays irradiated mice. (authors)

Fabrication of irradiation capsule for IASCC irradiation tests (2). Irradiation capsule for crack propagation test (Joint research)

International Nuclear Information System (INIS)

Ide, Hiroshi; Matsui, Yoshinori; Kawamata, Kazuo; Taguchi, Taketoshi; Kanazawa, Yoshiharu; Onuma, Yuichi; Watanabe, Hiroyuki; Inoue, Shuichi; Izumo, Hironobu; Ishida, Takuya; Saito, Takashi; Ishitsuka, Etsuo; Kawamura, Hiroshi; Kaji, Yoshiyuki; Ugachi, Hirokazu; Tsukada, Takashi

2008-03-01

It is known that irradiation Assisted Stress Corrosion Cracking (IASCC) occurs when austenitic stainless steel components used for light water reactor (LWR) are irradiated for a long period. In order to evaluate the high aging of the nuclear power plant, the study of IASCC becomes the important problem. The specimens irradiated in the reactor were evaluated by post irradiation examination in the past study. For the appropriate evaluation of IASCC, it is necessary to test it under the simulated LWR conditions; temperature, water chemistry and irradiation conditions. In order to perform in-pile SCC test, saturated temperature capsule (SATCAP) was developed. There are crack growth test, crack propagation test and so on for in-pile SCC test. In this report, SATCAP for crack propagation test is reported. (author)

Fabrication of irradiation capsule for IASCC irradiation tests (1). Irradiation capsule for crack growth test (Joint research)

International Nuclear Information System (INIS)

Ide, Hiroshi; Matsui, Yoshinori; Kawamata, Kazuo; Taguchi, Taketoshi; Kanazawa, Yoshiharu; Onuma, Yuichi; Watanabe, Hiroyuki; Inoue, Shuichi; Izumo, Hironobu; Ishida, Takuya; Saito, Takashi; Ishitsuka, Etsuo; Kawamura, Hiroshi; Kaji, Yoshiyuki; Ugachi, Hirokazu; Tsukada, Takashi

2008-03-01

It is known that Irradiation Assisted Stress Corrosion Cracking (IASCC) occurs when austenitic stainless steel components used for light water reactor (LWR) are irradiated for a long period. In order to evaluate the high aging of the nuclear power plant, the study of IASCC becomes the important problem. The specimens irradiated in the reactor were evaluated by post irradiation examination in the past study. For the appropriate evaluation of IASCC, it is necessary to test it under the simulated LWR conditions; temperature, water chemistry and irradiation conditions. In order to perform in-pile SCC test, saturated temperature capsule (SATCAP) was developed. There are crack growth test, crack propagation test and so on for in-pile SCC test. In this report, SATCAP for crack growth test is reported. (author)

PCR detection of Burkholderia multivorans in water and soil samples.

Science.gov (United States)

Peeters, Charlotte; Daenekindt, Stijn; Vandamme, Peter

2016-08-12

Although semi-selective growth media have been developed for the isolation of Burkholderia cepacia complex bacteria from the environment, thus far Burkholderia multivorans has rarely been isolated from such samples. Because environmental B. multivorans isolates mainly originate from water samples, we hypothesized that water rather than soil is its most likely environmental niche. The aim of the present study was to assess the occurrence of B. multivorans in water samples from Flanders (Belgium) using a fast, culture-independent PCR assay. A nested PCR approach was used to achieve high sensitivity, and specificity was confirmed by sequencing the resulting amplicons. B. multivorans was detected in 11 % of the water samples (n = 112) and 92 % of the soil samples (n = 25) tested. The percentage of false positives was higher for water samples compared to soil samples, showing that the presently available B. multivorans recA primers lack specificity when applied to the analysis of water samples. The results of the present study demonstrate that B. multivorans DNA is commonly present in soil samples and to a lesser extent in water samples in Flanders (Belgium).

Irradiation and Post-Irradiation Storage of Chicken: Effects on Fat and Proteins

International Nuclear Information System (INIS)

Abou-Tarboush, H.M.; Al-Kahtani, H.A.; Abou-Arab, A.A.; Atia, M.; Bajaber, A.S.; Ahmed, M.A.; El-Mojaddidi, M.A.

1997-01-01

Chicken were subjected to gamma irradiation doses of 2.5, 5.0, 7.5 and 10.0 KGy and post-irradiation storage of 21 days at 4±2º. The effects on fat and protein of chicken were studied. Rate of formation of total volatile basic-nitrogen was less in irradiated samples particularly in samples treated with 5.0KGy during the entire storage. Fatty acid profiles of chicken lipids were not significantly (P≤ 0.05) affected by irradiation especially at doses of 5.0 KGy. However, irradiation caused a large increase in thiobarbituric acid (TBA) values which continued gradually during storage. Changes in amino acids were minimal. Irradiated and unirradiated samples showed the appearance of protein subunits with molecular weights in the range of 10.0 to 88.0 and 10.0 to 67.0 KD, respectively. No changes were observed in the sarcoplasmic protein but the intensity of bands in all irradiated samples decreased after 21 days of storage

Sprout inhibition by gamma irradiation in fresh ginger (Zingiber officinale Roscoe)

International Nuclear Information System (INIS)

Yusof, N.

1990-01-01

A study on sprout inhibition by gamma irradiation in fresh ginger of a local variety was carried out. Fresh ginger was irradiated at the doses of 0, 25, 50 and 80 Grays (Gy) and stored at temperature 25-28 degrees C and relative humidity ranging from 76-96% for 4 months. The parameters observed were physiological weight loss, sprouting, external appearance, fungal infection, moisture content, water activity, crude fiber content and total sugar. The results show that irradiation at the doses studied effectively inhibited sprouting in ginger when compared to the nonirradiated samples. However, radiation was unable to extend the shelf-life as all samples started to deteriorate after 2 months storage

Study irradiation damage by fast neutrons in Portland cement by means of ultra-sound

International Nuclear Information System (INIS)

Rosa Junior, A.A.

1988-01-01

The effect of neutron irradiation in samples of Portland cement paste was evaluated, using the resonance frequency method and pulse velocity of ultra-sound technique. The samples were divide in three groups: 1) Monitoring samples; 2) Samples to gamma heating simulation; 3) Fast neutron irradiated samples in reactor core. Santa Rita Portland cement was utilized for samples preparation with water-cement rate of 0,40 l/kg. The irradiation was performed in the research reactor IEA-R1, at IPEN-CNEN/SP, with an integrated flux of 7,2 X 10 sup(18) n/cm sup(2) (E approx. 1 Mev). The samples of group 2 were submitted to special micro-waves heat treatment-with the same number of cycles of the reactor-which allowed the detection of fast neutron radiation effects within the predominant thermal effects. (author)

Effect of heat treatment oanas irradiation, and combined treatment on the shelf of fresh avocados (Persea americana L)

International Nuclear Information System (INIS)

Purwanto, Z.I.; Maha, Munsiah

1987-01-01

Effects of heat treatment, gamma irradiation, and combined treatments on the shelf-life of fresh avocados (Persea americana L.). Experiments to determine the effective irradiation conditions to prolong the shelf-life of fresh avocados were conducted at the centre for the Application of Isotopes washed and dried, then divided into 4 groups, namely for control (A), dipped in hot water at 40 0 C for 20 minutes (heat treatment, B), irradiated at a dose of 25 Gy (C), and combination of hot water dipping (40 0 C for 20 minutes) and irradiation at a 25 Gy (D). The samples were stored at room temperature. Evaluation on physical and chemical properties of the samples was done daily up to 10 days' storage. Parameters observed were texture, moisture and fat contents, percentage of weight loss, percentage of mature fruit, and subjective organoleptic evaluation. It was found that treated samples with and without combination treatment were still in good condition until 10 days of storage. It could be concluded that dipping in hot water, either alone or in combination with irradiation at a dose of 25 Gy could extend the shelf-life of fresh avocado up to 10 days at room temperature compared to only 5 days of the control. (author). 2 figs, 8 refs

Sampling procedure, receipt and conservation of water samples to determine environmental radioactivity

International Nuclear Information System (INIS)

Herranz, M.; Navarro, E.; Payeras, J.

2009-01-01

The present document informs about essential goals, processes and contents that the subgroups Sampling and Samples Preparation and Conservation believe they should be part of the procedure to obtain a correct sampling, receipt, conservation and preparation of samples of continental, marine and waste water before qualifying its radioactive content.

Water and sewage sludge disinfection by irradiation. Pt. 3. La desinfection des eaux et des boues residuaires par irradiation. Pt. 3

Energy Technology Data Exchange (ETDEWEB)

Alexandre, D [CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Dept. de Chimie Appliquee

1978-01-01

In view of disinfestation of water and sludges qualitative aspects of irradiation are given. Effects of different parameters: pH, dose rate, hydratation, synergism of oxygen, heat and chlorine are examined. No toxic products are created by radiations. Filtrability and decantability of sludges are improved.

The effects of gamma irradiation on leaching of 137Cs from organic matrix wasteforms

International Nuclear Information System (INIS)

Burnay, S.G.; Johnson, D.I.; Phillips, D.C.; Brownsword, M.

1987-09-01

The effects of γ-irradiation on the leaching behaviour of 137 Cs in organic matrix wasteforms has been studied. The matrix materials used include epoxide, polyester and vinyl ester thermosetting resins and bitumen. Leaching of 137 Cs in such matrices can be described by models, based on diffusion, which take into consideration such factors as non-representative surface layers, finite sample size, and sorption effects. In many cases, the changes observed on irradiation arise from modification of the sorptive capacity of the wasteform for 137 Cs, producing changes in the experimentally observed diffusion coefficients. In samples containing wet wastes, enhanced leaching in the first few days is observed after irradiation. This arises from loss of water from the sample surfaces during irradiation producing an enhanced concentration of the radionuclide in the surface. (author)

Disinfection of hepatitis A virus and MS-2 coliphage in water by ultraviolet irradiation: comparison of UV-susceptibility

Energy Technology Data Exchange (ETDEWEB)

Widenmann, A.; Fischer, B.; Straub, U.; Wang, C. H.; Flehmig, B.; Schoenen, D. [Abteilung für Allgemeine Hygiene und Umwelthygiene, Hygiene-Institut der Universitat Tubingen, D-7400 Tubingen (Germany)

1993-07-01

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of HAV to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might tlierefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quarz cuvette at 254 nm. For a reduction rate of four log units a three times lighter UV dose was required with MS-2 than with HAV.

Irradiation-assisted stress corrosion cracking of austenitic alloys

International Nuclear Information System (INIS)

Was, G.S.; Atzmon, M.

1991-01-01

An experimental program has been conducted to determine the mechanism of irradiation-assisted stress-corrosion cracking (IASCC) in austenitic stainless steel. High-energy protons have been used to produce grain boundary segregation and microstructural damage in samples of controlled impurity content. The densities of network dislocations and dislocation loops were determined by transmission electron microscopy and found to resemble those for neutron irradiation under LWR conditions. Grain boundary compositions were determined by in situ fracture and Auger spectroscopy, as well as by scanning transmission electron microscopy. Cr depletion and Ni segregation were observed in all irradiated samples, with the degree of segregation depending on the type and amount of impurities present. P, and to a lesser extent P, impurities were observed to segregate to the grain boundaries. Irradiation was found to increase the susceptibility of ultra-high-purity (UHP), and to a much lesser extent of UHP+P and UHP+S, alloys to intergranular SCC in 288 degree C water at 2 ppm O 2 and 0.5 μS/cm. No intergranular fracture was observed in arcon atmosphere, indicating the important role of corrosion in the embrittlement of irradiated samples. The absence of intergranular fracture in 288 degree C argon and room temperature tests also suggest that the embrittlement is not caused by hydrogen introduced by irradiation. Contrary to common belief, the presence of P impurities led to a significant improvement in IASCC over the ultrahigh purity alloy

Chemiluminescent Determination of Oxamyl in Drinking Water and Tomato Using Online Postcolumn UV Irradiation in a Chromatographic System.

Science.gov (United States)

Murillo Pulgarín, José A; García Bermejo, Luisa F; Durán, Armando Carrasquero

2018-03-07

High-performance liquid chromatography (HPLC) was used to separate oxamyl from other pesticides in drinking water and tomato paste. The eluate emerging from the column tail was mixed with an alkaline solution of Co 2+ in EDTA and irradiated with UV light to induce photolysis of the carbamate in order to obtain free radicals and other reactive species that oxidize luminol and produce chemiluminescence (CL) as a result. The intensity of the CL signal was monitored in the form of chromatographic peaks. Under the optimum operating conditions for the HPLC-UV-CL system, the analyte concentration was linearly related to peak area. The limit of detection as determined in accordance with the IUPAC criterion was 0.17 mg L -1 . Oxamyl was successfully extracted with recoveries of 88.7-103.1% from spiked tomato paste by using a simple QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) sample preparation approach. Similar recoveries were obtained from drinking water samples spiked with oxamyl concentrations above the LOD. The proposed method is a simple, fast, accurate choice for quantifying this pesticide.

Modified fuel channel for sample irradiation at the RB reactor

International Nuclear Information System (INIS)

Pesic, M.; Markovic, H.; Sokcic, M.; Miric, I.; Prokic, M.; Strugar, P.

1983-01-01

Fuel channel of 80% enriched UO 2 at RB reactor in Boris Kidric Institute of nuclear sciences is modified for sample irradiation in the fast neutron field. Maximum sample diameter is 25 mm and length up to 100 mm. Characteristics of neutron as well as gamma radiation fields of this new experimental channel are investigated. In the center of channel, the main contribution to the total neutron absorbed dose i.e. 0.29 Gy per 1 Wh of reactor operation, is due to the fast neutron spectrum component. Only 0.05 Gy and 0.07 Gy in the total neutron absorbed dose are due to epithermal and thermal neutrons respectively. At the same time gamma absorption dose is 0.35 Gy. The development of experimental fuel channel GRK has wide possibility for utilization, from electronic components fast neutron studies, dosimeters testing, to cross section measurements for fast neutron energies. (author)

Isolation of radioresistant microorganisms from a Co/sup 60/ irradiation plant

International Nuclear Information System (INIS)

Lezcano, Graciela

1982-01-01

The continuos exposition to low doses of gamma irradiation can produce changes in the microflora's radioresistance. In order to obtain information about these possible modifications, the water from the pool used as shielding of the source, as well as the air and the dust in the irradiation chamber of the semi-industrial irradiation plant existing at the Ezeiza Atomic Center were analyzed. The number of microorganisms was determined by filtration techniques and by dilutions. Radioresistance studies of the contaminating microflora were performed. The value of the D/sub 10/ dose was determined in the conditions of highest resistance. A pronounced decrease in the number of microorganisms was observed as a radiation effect in the samples of water and dust, but not in the air samples, this as a consequence of the extractors' action that continually renews the air and the flora in the chamber, thus preventing high-dose exposure. In the air samples no increase of the microorganisms' radioresistance was observed. In the pool water flora, the development of a great radioresistance was observed. A microorganism whose inactivation curve shows a shoulder of 3.2 Mrad was isolated. This high radioresistance could be the result of the continous exposure to low doses during six years. Contrarily, the microorganims of the irradiation chamber's dust did not increase their radioresistance wiht regard to the common contaminants. In the flora of the dust used as a target, two microorganims whose D/sub 10/ were in excess of 400 krad were found; these could be ocassional contaminants. The radioresistant microorganims were isolated and characterized according to Cowan's scheme, the water microorganisms being identified as belonging to the genus Corynebacterium and the earth ones to the genera Micrococcus and Corynebacterium. (author) [es

Thermoluminescent behavior of polyminerals from irradiated natural species (peppermint, pepper and origanum)

International Nuclear Information System (INIS)

Cruz Z, E.; Calderon, T.; Pineda, S.; Guzman M, A.; Gastelum, S.; Barboza F, M.; Calderon, T.

2003-01-01

The thermoluminescent behaviour of polyminerals from natural species was obtained in order to identify irradiated samples. The polyminerals was separated from organic part in the samples using methanol-water mixed 40:60. The commercial samples was exposured from 1 to 40 kGy in Gammabeam 651PT facility irradiator at National University of Mexico (UNAM). The glow curves from polyminerals shows a good behaviour for each dose, and the TL emission decays was present for 180 days storage in a dark room at room temperature. The maximum TL signals was located in around 220 for the samples, it is closely to TL emission from quartz and feldspars. (Author)

Simulation of gamma-ray irradiation of lettuce leaves in a 137Cs irradiator using MCNP

International Nuclear Information System (INIS)

Kim, Jongsoon; Moreira, Rosana G.; Braby, Leslie A.

2010-01-01

Ionizing radiation effectively reduces the number of common microbial pathogens in fresh produce. However, the efficacy of the process for pathogens internalized into produce tissue is unknown. The objective of this study was to understand gamma irradiation of lettuce leaf structure exposed in a 137 Cs irradiator using MCNP. The simulated 137 Cs irradiator is a self-shielded device, and its geometry and sources are described in the MCNP input file. When the irradiation chamber is filled with water, lower doses are found at the center of the irradiation volume and the dose uniformity ratio (maximum dose/minimum dose) is 1.76. For randomly oriented rectangular lettuce leaf segments in the irradiation chamber, the dose uniformity ratio is 1.25. It shows that dose uniformity in the Cs irradiator is strongly dependent of the density of the sample. To understand dose distribution inside the leaf, we divided a lettuce leaf into a low density (flat) region (0.72 g/cm 3 ) and high density (rib) region (0.86 g/cm 3 ). Calculated doses to the rib are 61% higher than doses to the flat region of the leaf. This indicates that internalized microorganisms can be inactivated more easily than organisms on the surface. This study shows that irradiation can effectively reduce viable microorganism internalized in lettuce. (author)

Post irradiation examination of type 316 stainless steels for in-pile Oarai water loop No.2 (OWL-2)

International Nuclear Information System (INIS)

Shibata, Akira; Kimura, Tadashi; Nagata, Hiroshi; Aoyama, Masashi; Kanno, Masaru; Ohmi, Masao

2010-11-01

The Oarai water loop No.2 (OWL-2) was installed in JMTR in 1972 for the purpose of irradiation experiments of fuel element and component material for light water reactors. Type 316 stainless steels (SSs) were used for tube material of OWL-2 in the reactor. But data of mechanical properties of highly irradiated Type 316 SSs has been insufficient since OWL-2 was installed. Therefore surveillance tests of type 316 SSs which were irradiated up to 3.4x10 25 n/m 2 in fast neutron fluence (>1 MeV) were performed. Meanwhile type 316 stainless steel (SS) is widely used in JMTR such as other irradiation apparatus and irradiation capsule, and additional data of type 316 SSs irradiated higher is required. Therefore post irradiation examinations of surveillance specimens made of type 316 SSs which were irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence were performed and reported in this paper. In this result of surveillance tests of type 316 SSs irradiated up to 1.0x10 26 n/m 2 , tensile strength increase with increase of Neutron fluence and total elongation decreased with increase of Neutron fluence compared to unirradiated specimens and specimens irradiated up to 3.4x10 25 n/m 2 . This tendency has good agreement with results of 10 24 - 10 25 n/m 2 in fast neutron fluence. More than 37% in total elongation was confirmed in all test conditions. It was confirmed that type 316 SS irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence has enough ductility as structure material. (author)

Antioxidant activity of extract from gamma irradiated grape (Psidium guajava L.) seeds

International Nuclear Information System (INIS)

Abdeldaiem, M. H.; Ali, H.G.M.; Nasr, E.H.

2012-01-01

The objective this study was to study the antioxidant activity efficiency of extracts from irradiated defatted guava (Psidium guajava L.) seeds at dose levels of 0, 2, 4 and 6 kGy. The non-irradiated and irradiated defatted guava seeds samples were extracted with acetone: water: acetic acid (90:9.5:0.5). Immediately after irradiation, the antioxidant activity was studied. Gas chromatographic-Mass spectrum was applied to identify and quantify the constituents (%) of extracts and the amino acids composition was determined in all samples under investigation of defatted guava seeds powder. The measurements of the antioxidant activity, using a γ-carotene-linoleate model system and radical scavenging capacity effect on 2, 2-diphenyl-1- picrylhydrazyl (DPPH) radical, was determined in the extracts of non-irradiated and irradiated defatted guava seeds powder. Meanwhile, noodles (homemade strips macaroni) were prepared from blends of 72% wheat flour containing 0, 2.5, 5 and 7.5% levels of non-irradiated defatted guava seeds powder. The results showed that samples of extracts from non-irradiated and irradiated defatted guava seeds had contained a considerable total polyphenolic compounds and marked scavenging activity on DPHH radical. On the other hand , the gas chromatography (GC) and mass spectroscopy (MS) separation technique led to identification of 26 components the of extract non-irradiated and irradiated samples. Also, the data revealed that guava seeds powder samples under investigation passes the most important essential amino acids and for human health such as trace elements iron, zinc and manganese. Noodles prepared from 2.5% level of guava seeds powder-wheat flour blend had high acceptable quality. Thus, guava seeds, a waste from guava industry can be utilized improved nutritional properties of noodles or used its extracts as natural antioxidant in food industry field

Isolation of Enterobacter cowanii in tomatoes after gamma irradiation; Isolamento de Enterobacter cowanii em tomates apos irradiacao gama

Energy Technology Data Exchange (ETDEWEB)

Vicalvi, M.C.V.; Solidonio, E.G.; Silva, M.A.; Colaco, W., E-mail: claudiavicalvi@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos Graduacao em Tecnologias Energeticas e Nucleares; Silva, G.R. da; Sena, K.X.F.R de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Lab. de Antibioticos

2013-08-15

The tomato is one of the most consumed fruit in the world. Bacteria of the family Enterobacteriaceae are responsible for large outbreaks of gastroenteritis. Irradiation is a physical method which reduces waste by eliminating spoilage organisms in foods. The objective of this study was to identify and determine the resistance profile of micro-organisms of the family Enterobacteriaceae from irradiated tomatoes. Were used three batches each containing 80 tomatoes, and divided in control and irradiated. The samples were individually properly identified as the irradiation dose applied. The material was subjected to irradiation with gamma rays, for irradiating with a cobalt-60 source, using doses: 1.0, 1.5 and 2 kGy (6,060 kGy/h). For microbiological analysis tomatoes were cut out, and removing the shells to obtain samples weighing 25g. Each sample was transferred to an Erlenmeyer containing sterilized water, stirring the assembly mechanically. Aliquots of the wash waters were sown in differential and selective media. After reisolation, the colonies were subjected to Gram staining then performed biochemical tests for identification. The antibiotic susceptibility tests were performed according to CLSI (Clinical Laboratory Standard Institute). It was isolated three strains of Enterobacter cowanii in tomato samples irradiated with a dose of 1.0 kGy, without isolating the other doses. As for the resistance profile, the strains were resistant to Ampicillin identified. Gamma irradiation at a dose of 1.5 and 2 kGy was effective in tomatoes as well as the micro-organism isolated after irradiation showed no profile of multidrug resistance. (author)

UMTRA water sampling and analysis plan, Green River, Utah

International Nuclear Information System (INIS)

Papusch, R.

1993-12-01

The purpose of this water sampling and analysis plan (WSAP) is to provide a basis for groundwater and surface water sampling at the Green River Uranium Mill Tailing Remedial Action (UMTRA) Project site. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations

Mock-up experiments for the project of high dose irradiation on the RPV concrete

International Nuclear Information System (INIS)

Zdarek, J.; Brabec, P.; Frybort, O.; Lahodova, Z.; Vit, J.; Stemberk, P.

2015-01-01

Aging of NPP's concrete structures comes into growing interest in connection with solution of life extension programmes of operated units. Securing continued safe operation of NPPs calls for additional proofs of suitable long term behaviour of loaded reinforced concrete structures. An irradiation test of concrete samples was performed in the core of the LVR-15 reactor. The irradiation capsule was hung in the irradiation channel and the cooling of the capsule was ensured through direct contact of the capsule wall with the primary circuit water. Cylindrical, serpentine concrete samples (50 mm in diameter and 100 mm in length), representing composition of WWER RPV cavity, was chosen as a compromise of mechanical properties testing needs and dimension limitations of reactor irradiation channel. Heating during irradiation test was maintained under 93 Celsius degrees by cooling and was controlled by embedded thermocouple. Design of the cooling management was supported by computational analysis. The dependencies of heated concrete samples to the neutron fluence and the gamma heating were obtained by changing the thermal power of the reactor and by changing the vertical position of the sample in the irradiation channel. The irradiation capsule was filled with inert gas (helium) to allow the measurement of generated gas. The determination of concrete samples activity for long-term irradiation was performed on the principles of the Neutron Activation Analysis. Preliminary mock-up tests have proved the ability to fulfill technical needs for planned high dose irradiation experiment

Review of recent studies on neutron irradiation embrittlement in light water reactor pressure vessel steels

International Nuclear Information System (INIS)

Sudo, Akira; Miyazono, Shohachiro

1983-06-01

Recent studies in foreign countries (USA, France, FRG and UK) on neutron irradiation embrittlement have been reviewed. These studies are classified into four areas, such as 1) effect of chemical composition on irradiation embrittlement sensitivity, 2) postirradiation heat treatment for embrittlement relief, 3) fracture toughness evaluation of irradiated materials based on fracture mechanics analysis, and 4) effect of irradiation on fatigue crack propagation behavior. The first area mainly includes the studies related to the effects of copper, phosphorus impurities and nickel alloying and synergistic effect of these components, and furthermore, evaluation of Regulatory Guide 1.99 Rev.l. Studies in the second area show the effects of annealing condition (temperature and time) and metallugical condition on embrittlement relief, and evaluation of periodic annealing in the period of irradiation as a promising method for embrittlement control. Studies in the third area show the correlation between fracture toughness and Cv notch ductility changes with neutron irradiation, and J-R curves of irradiated materials based on the elasto-plastic fracture mechanics. In the forth area, most of studies are investigated in air condition but a few studies in reactor-grade water at high temperature and pressure. (author)

Changes in the lipid fraction of eel gills after ionizing irradiation in vivo and a shift from fresh to sea water

International Nuclear Information System (INIS)

Hansen, H.J.M.

1975-01-01

Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ radiation and four of the irradiated group and four of the nonirradiated control group were transferred to seawater. The rest remained in tap water. Three days later all were incubated with 14 C-labeled acetate and 32 P-labeled phosphate added to the water in the aquariums. Lipids from the gills were separated by tlc and the individual fatty acids were assayed by paper chromatography. Results showed an enhanced incorporation of 14 C activity into sterol esters in seawater. This was further intensified by γ irradiation. Similarly, γ irradiation intensified a relatively enhanced incorporation in seawater of 32 P activity into lecithin, and there was a relatively increased synthesis of certain 14 C-labeled unsaturated fatty acids (mainly C 16 : 1 ) in the gills of animals that had both been irradiated and transferred to seawater. By measuring lipid biosynthesis in gill tissue it was thus possible to show an interaction between the effect of ionizing irradiation and the salinity of the environment, in agreement with previous biological findings. (U.S.)

Disinfection of hepatitis A virus and MS-2 coliphage in water by ultraviolet irradiation: comparison of UV-susceptibilty

Energy Technology Data Exchange (ETDEWEB)

Wiedenmann, A; Fischer, B; Straub, U; Wang, C -H; Flehmig, B [Tuebingen Univ. (Germany). Hygiene-Inst.; Schoenen, D [Bonn Univ. (Germany). Hygiene-Inst.

1993-01-01

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of Hepatitis A Virus (HAV) to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might therefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quartz cuvette at 254 nm. For a reduction rate of four log units a three times higher UV dose was required with MS-2 than with HAV. (author).

Disinfection of hepatitis A virus and MS-2 coliphage in water by ultraviolet irradiation: comparison of UV-susceptibilty

International Nuclear Information System (INIS)

Wiedenmann, A.; Fischer, B.; Straub, U.; Wang, C.-H.; Flehmig, B.; Schoenen, D.

1993-01-01

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of Hepatitis A Virus (HAV) to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might therefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quartz cuvette at 254 nm. For a reduction rate of four log units a three times higher UV dose was required with MS-2 than with HAV. (author)

Induced radioactivity in air and water at medical accelerators

International Nuclear Information System (INIS)

Masumoto, K.; Takahashi, K.; Nakamura, H.; Toyoda, A.; Iijima, K.; Kosako, K.; Oishi, K.; Nobuhara, F.

2013-01-01

Activation of air and water has been evaluated at the 10 and 15 MeV linear electron accelerator facilities. At 15 MeV irradiation, the activity of 10-min-half-life 13 N was observed in the case of the air in the glove box. Air and water samples were also bombarded by 250 MeV protons and 400 MeV/u carbon, and the irradiation dose was 10 Gy at the isocenter. Upon the ion-chamber monitoring of the air sampled from the glove box, 15 O, 13 N, and 11 C activities were mainly observed. At the end of proton and carbon irradiation, the activity of the water was found to be about 10 kBq·cm -3 and several kBq·cm -3 , respectively. From the decay analysis of the induced activity in water, 15 O, 13 N, and 11 C were detected. (author)

Modifications induced by gamma irradiation to Makrofol polymer nuclear track detector

Directory of Open Access Journals (Sweden)

A. Tayel

2015-03-01

Full Text Available The aim of the present study was extended from obtaining information about the interaction of gamma rays with Makrofol DE 7-2 track detector to introduce the basis that can be used in concerning simple sensor for gamma irradiation and bio-engineering applications. Makrofol polymer samples were irradiated with 1.25 MeV 60Co gamma radiations at doses ranging from 20 to 1000 kG y. The modifications of irradiated samples so induced were analyzed using UV–vis spectrometry, photoluminescence spectroscopy, and the measurements of Vickers’ hardness. Moreover, the change in wettability of irradiated Makrofol was investigated by the contact angle determination of the distilled water. UV–vis spectroscopy shows a noticeable decrease in the energy band gap due to gamma irradiation. This decrease could be attributed to the appearance of a shift to UV spectra toward higher wavelength region after irradiation. Photoluminescence spectra reveal a remarkable change in the integrated photoluminescence intensity with increasing gamma doses, which may be resulted from some matrix disorder through the creation of some defected states in the irradiated polymer. The hardness was found to increase from 4.78 MPa for the unirradiated sample to 23.67 MPa for the highest gamma dose. The contact angle investigations show that the wettability of the modified samples increases with increasing the gamma doses. The result obtained from present investigation furnishes evidence that the gamma irradiations are a successful technique to modify the Makrofol DE 7-2 polymer properties to use it in suitable applications.

Physico-chemical characteristics of water sample from Aiba Stream ...

African Journals Online (AJOL)

This study aimed at assessing the effectiveness of solar distillation in purification of water. The water sample collected from Aiba stream was subjected to double slope solar water distillation unit. The physico- chemical characteristics of the raw sample and the distillate were determined using standard methods. The.

Bacteriological quality of freshly processed broiler chickens as affected by carcass pretreatment and gamma irradiation

International Nuclear Information System (INIS)

Lamuka, P.O.; Sunki, G.R.; Chawan, C.B.; Rao, D.R.; Shackelford, L.A.

1992-01-01

Chicken carcasses dipped in whey fermented by Streptococcus thermophilus, lactic acid solution or water and irradiated at 2.5 kGy by 60Co were evaluated for bacteriological quality on day 1, day-3 and at 3-day intervals for an 18-day storage (4 degrees C) period. Unirradiated carcasses treated similarly were used as control. Gram negative bacteria, Yersinia and Campylobacter counts were significantly (p0.01) lower in irradiated samples, but no significant (p0.05) differences were observed ammong the dipping solutions. Salmonellae were completely eliminated in irradiated samples. Whey fermented by S. thermophilus reduced the proportion of Salmonella contaminated carcasses from 67% to 20%. As evidenced by the bacterial counts the shelf-life was found to be 15 days for irradiated carcasses compared to about 6 days for the unirradiated samples

Measurement of 90Sr in fresh water samples

International Nuclear Information System (INIS)

Belanova, A.; Meresova, J.; Svetlik, I.; Tomaskova, L.

2008-01-01

This preliminary study show new experimental approach to the determination of the radionuclide 90 Sr in water samples. The new method of dynamic windows utilizing liquid scintillation counting was applied on model and surface water samples. Our results show the demand of separation technique with significantly higher yields. (authors)

Irradiation-accelerated corrosion of reactor core materials

International Nuclear Information System (INIS)

Bartels, David; Was, Gary; Jiao, Zhijie

2012-09-01

irradiation will include all three effects: water radiolysis, electronic excitation, and displacement damage. Electron irradiation will omit the displacement damage, while the corrosion potential can be manipulated separately by chemical additives. Extensive ex-situ diagnostics will be applied to examine the structure and morphology of corrosion films grown under the three different conditions. In situ diagnostics will include Raman spectroscopy and electrochemical impedance measurements as irradiation proceeds. The experimental challenge for proton irradiation with 3.4 MeV protons, is the very high stopping power of the steel, which necessitates samples at the vacuum-high pressure water interface of only 35 microns thickness. The high stopping power of protons also guarantees a very high dose rate to the water (and also the oxide film) within microns of the surface. To mimic this high dose rate and its corresponding local corrosion potential, very high electron beam currents are required. The presentation will review previous work in this area, and highlight the gaps in available knowledge of radiation-enhanced corrosion. The new experiments will be described in detail, and the most recent results will be presented. (authors)

Development of small scale mechanical testing techniques on ion beam irradiated 304 SS

International Nuclear Information System (INIS)

Reichardt, A.; Abad, M.D.; Hosemann, P.; Lupinacci, A.; Kacher, J.; Minor, A.; Jiao, Z; Chou, P.

2015-01-01

Austenitic stainless steels are widely used for structural components in light water reactors, however uncertainty in their susceptibility to irradiation assisted stress corrosion cracking (IASCC) has made long term performance predictions difficult. In addition, the testing of reactor irradiated materials has proven challenging due to the long irradiation times required, limited sample availability, and unwanted activation. To address these problems, we apply recently developed techniques in nano-indentation and micro-compression testing to small volume samples of 10 dpa proton-beam irradiated 304 stainless steel. Cross sectional nano-indentation was performed on both proton beam irradiated and non-irradiated samples at temperatures ranging from 22 to 300 C. degrees to determine the effects of irradiation and operating temperature on hardening. Micro-compression tests using 2 μm x 2 μm x 5 μm focused-ion beam milled pillars were then performed in situ in an electron microscope to allow for a more accurate look at stress-strain behavior along with real-time observations of localized mechanical deformation. Large sudden slip events and significant increase in yield strength are observed in irradiated micro-compression samples at room temperature. Elevated temperature nano-indentation results reveal the possibility of thermally-activated changes in deformation mechanism for irradiated specimens. Since the deformation mechanism information provided by micro-compression testing can provide valuable information about IASCC susceptibility, future work will involve ex situ micro-compression tests at reactor operating temperature

Removal of endocrine disruptors PAEs in drinking water by gamma-ray irradiation

International Nuclear Information System (INIS)

Zhao Yongfu; Zheng Zheng; Zheng Binguo; Wang Changbao; Li Lili

2012-01-01

Phthalic acid esters (PAEs) belong to environmental endocrine disruptor. The dimethyl phthalate (DMP), diethyl phthalate (DEP) and di-n-butyl phthalate (DBP) were selected for the radiation study. The removal efficiencies of DMP, DEP and DBP in drinking water by gamma-ray irradiation are discussed. The results show that these PAEs could be efficiently removed by gamma-ray irradiation. The removal efficiencies of DMP, DEP and DBP (12 mg/L) in aqueous solutions by 0.8 kGy gamma-ray treatment were 96.6%, 94.5% and 86.2%. The absorbed dose needed for the removal of total carbon in aqueous solutions was much larger than the doses for PAEs degradation. When 2 kGy was selected, the removal efficiencies of TC for DMP, DEP and DBP were only 23.6%, 14.3% and 12.9%. The study results also show that the radiation degradation reaction of PAEs should be divided into two stages: low dose addition reaction and high dose ring-opening reaction. This study is of significance in the disposal of micro-polluted drinking water. (authors)

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.

Effects of gamma radiation on maize samples contaminated with Fusarium verticillioides

International Nuclear Information System (INIS)

Ferreira-Castro, F.L.; Aquino, S.; Greiner, R.; Ribeiro, D.H.B.; Reis, T.A.; Correa, B.

2007-01-01

The efficacy of γ-irradiation as a method of decontamination of maize containing Fusarium verticillioides under controlled conditions of relative humidity (RH) (97.5%) and water activity has been studied. Maize grains inoculated with a spore suspension of F. verticillioides were irradiated to 2, 5, and 10 kGy. Thereafter, the irradiated and control samples were analyzed for the presence of fumonisins, their viable cells were counted, and their morphology was investigated by electronic microscopy. It was found possible to decrease the risk of exposure to fumonisins by irradiating maize to 5 or 10 kGy. However, at the dose of 2 kGy, the survived fungi (36%) can produce more fumonisins than the fungi in the control unirradiated samples under the same conditions

Impacts of Saharan dust on downward irradiance and photosynthetically available radiation in the water column

Directory of Open Access Journals (Sweden)

T. Ohde

2012-09-01

Full Text Available A semi-empirical approach was used to quantify the modification of the underwater light field in amplitude (magnitude effect and spectral distribution (spectral effect by different atmospheric conditions altering the incident light. The approach based on an optical model in connection with radiation measurements in the area off Northwest Africa. Key inputs of the model were parameterized magnitude and spectral effects. Various atmospheric conditions were considered: clear sky, dusty sky without clouds, cloudy sky without dust and skies with different ratios of dust and clouds. Their impacts were investigated concerning the modification of the downward irradiance and photosynthetically available radiation in the water column. The impact on downward irradiance depended on the wavelength, the water depth, the optical water properties, the dust and cloud properties, and the ratio of clouds to dust. The influence of clouds on the amplitude can be much higher than that of dust. Saharan dust reduced the photosynthetically available radiation in the water column. Ocean regions were more influenced than coastal areas. Compensations of the magnitude and spectral effects were observed at special water depths in ocean regions and at atmospheric conditions with definite cloud to dust ratios.

Irradiated gelatin-potato starch blends: evaluation of physicochemical properties

International Nuclear Information System (INIS)

Inamura, Patricia Y.; Regis, Wellington; Mastro, Nelida L.

2015-01-01

Macromolecular polysaccharides of large chains as starch can interlace with gelatin modifying their mechanical resistance. In this work, biodegradable bovine gelatin-potato starch blends films were developed using glycerol as plasticizer. Three formulations of gelatin/starch proportions (w/w) were used (1:0; 3:1; 1:1) and casting was the chosen method. The dried samples were then submitted to ionizing radiation coming from an electron beam (EB) accelerator with doses of 20 and 40 kGy, at room temperature, in the presence of air. Mechanical properties such as puncture strength and elongation at break were measured. Color measurements, water absorption, moisture, and film solubility were assessed. The results showed that starch addition to films based on gelatin as well as irradiation affected physical and structural properties of the films. Although the increase of starch content in the mixture led to decrease of the puncture force even in samples irradiated with the higher dose, there was a decrease of water absorption of films with the increase of the dose, and also by the higher starch content. Samples irradiated at 20 kGy presented higher moisture and film solubility. The methodology developed in this paper can be applied to other composite systems to establish the best protein:starch ratio, and the contribution of the radiation crosslinking in each specific case. (author)

Irradiated gelatin-potato starch blends: evaluation of physicochemical properties

Energy Technology Data Exchange (ETDEWEB)

Inamura, Patricia Y.; Regis, Wellington; Mastro, Nelida L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Macromolecular polysaccharides of large chains as starch can interlace with gelatin modifying their mechanical resistance. In this work, biodegradable bovine gelatin-potato starch blends films were developed using glycerol as plasticizer. Three formulations of gelatin/starch proportions (w/w) were used (1:0; 3:1; 1:1) and casting was the chosen method. The dried samples were then submitted to ionizing radiation coming from an electron beam (EB) accelerator with doses of 20 and 40 kGy, at room temperature, in the presence of air. Mechanical properties such as puncture strength and elongation at break were measured. Color measurements, water absorption, moisture, and film solubility were assessed. The results showed that starch addition to films based on gelatin as well as irradiation affected physical and structural properties of the films. Although the increase of starch content in the mixture led to decrease of the puncture force even in samples irradiated with the higher dose, there was a decrease of water absorption of films with the increase of the dose, and also by the higher starch content. Samples irradiated at 20 kGy presented higher moisture and film solubility. The methodology developed in this paper can be applied to other composite systems to establish the best protein:starch ratio, and the contribution of the radiation crosslinking in each specific case. (author)

Influence of E-beam irradiation on dielectric relaxation of recycled polypropylene

International Nuclear Information System (INIS)

Fazilova, Z.; Gafurov, U.; Tolstov, A.

2004-01-01

Full text: The dielectric relaxation connected with molecular groups and polymer chain mobility for un-irradiated and e-beam irradiated recycled polypropylene was investigated. It was studied films of samples produced from virgin (initial) and e- beam irradiated of the polymer granules (E-beam source with 5 MeV energy). The dielectric losses were measured with temperature increasing and decreasing regime. The losses were measured with E8-4 bridge help (the frequency is 1kH). Heating velocity was 2 grad/min. The dielectric losses did not appeared in minus temperature region for the initial polypropylene samples. The measurement in temperature increasing and decreasing shows that the relaxation peak at ∼ 35 o C for un-irradiated and ∼70 o C for irradiated polymer samples connected with macromolecular segments mobility with water molecular groups participation. The main relaxation peak (higher 100 o C) shifts after e-beam irradiation is result of the cross-links formation. ) The peak connected with macromolecular segments mobility in polymer amorphous regions (β-relaxation process). In irradiated polypropylene on IR spectroscopy data oxygen molecular groups is increased. The molecular groupings form inter-molecular hydrogen bonds. The intermolecular bonds also hindered molecular groups and macromolecular mobility. The e-beam stimulated cross-links formation was confirmed by method of sol-gel analyses. The work was supported by STCU Fund (Project No 3009)

UMTRA project water sampling and analysis plan -- Shiprock, New Mexico

International Nuclear Information System (INIS)

1994-02-01

Water sampling and analysis plan (WSAP) is required for each U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site to provide a basis for ground water and surface water sampling at disposal and former processing sites. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring stations at the Navaho Reservation in Shiprock, New Mexico, UMTRA Project site. The purposes of the water sampling at Shiprock for fiscal year (FY) 1994 are to (1) collect water quality data at new monitoring locations in order to build a defensible statistical data base, (2) monitor plume movement on the terrace and floodplain, and (3) monitor the impact of alluvial ground water discharge into the San Juan River. The third activity is important because the community of Shiprock withdraws water from the San Juan River directly across from the contaminated alluvial floodplain below the abandoned uranium mill tailings processing site

Analysis of phthalate esters contamination in drinking water samples ...

African Journals Online (AJOL)

The optimum condition method was successfully applied to the analysis of phthalate esters contamination in bottled drinking water samples. The concentration of DMP, DEP and DBP in drinking water samples were below allowable levels, while the DEHP concentration in three samples was found to be greater than the ...

Determination of Phthalates in Drinking Water Samples

African Journals Online (AJOL)

user

successfully applied to the analysis of phthalate esters contamination in bottled drinking water samples. ... esters are used in the manufacturing of polyvinyl chloride. (PVC). ... water, soil, air, food products and the human body. (Castillo et al.

ESR identification of irradiated foodstuffs: LARQUA research

Energy Technology Data Exchange (ETDEWEB)

Raffi, J [Laboratoire de Recherche sur la Qualite des Aliments, Marseille (France)

1997-12-31

As electron spin resonance (ESR) spectroscopy is the leading method for identification of irradiated foodstuffs, meat and fish bones, fruit and relative products (of vegetable origin), sea-food etc. were studied. In order to prepare a large co-trial on ESR identification of irradiation of irradiated foodstuffs, experiments were carried out at LARQUA, especially on fruits and vegetables. The radicals induced in the fruit pulp are not stable because the water content of fruit is generally high, but ESR can be used with dried fruit or dry components such as achenes, pips or stones. Different responses are observed, depending on the fruit. In ``sugatype`` fruits (papaya, dried grapes), an ESR multicomponent signal is radio-induced, but the non-irradiated fruit presents no ESR signal or a single-line, while in ``cellulose type`` fruits (pistachio nut, berries), a triplet is induced. But a six line signal due to Mn{sup 2+} and a central single line may also be present both in irradiated and non-irradiated samples. In the case of aromatic herbs, the proposed official CEN protocol for irradiated food containing cellulose was used. (author).

ESR identification of irradiated foodstuffs: LARQUA research

International Nuclear Information System (INIS)

Raffi, J.

1996-01-01

As electron spin resonance (ESR) spectroscopy is the leading method for identification of irradiated foodstuffs, meat and fish bones, fruit and relative products (of vegetable origin), sea-food etc. were studied. In order to prepare a large co-trial on ESR identification of irradiation of irradiated foodstuffs, experiments were carried out at LARQUA, especially on fruits and vegetables. The radicals induced in the fruit pulp are not stable because the water content of fruit is generally high, but ESR can be used with dried fruit or dry components such as achenes, pips or stones. Different responses are observed, depending on the fruit. In ''sugatype'' fruits (papaya, dried grapes), an ESR multicomponent signal is radio-induced, but the non-irradiated fruit presents no ESR signal or a single-line, while in ''cellulose type'' fruits (pistachio nut, berries), a triplet is induced. But a six line signal due to Mn 2+ and a central single line may also be present both in irradiated and non-irradiated samples. In the case of aromatic herbs, the proposed official CEN protocol for irradiated food containing cellulose was used. (author)

Transfer of test samples and wastes between post-irradiation test facilities (FMF, AGF, MMF)

International Nuclear Information System (INIS)

Ishida, Yasukazu; Suzuki, Kazuhisa; Ebihara, Hikoe; Matsushima, Yasuyoshi; Kashiwabara, Hidechiyo

1975-02-01

Wide review is given on the problems associated with the transfer of test samples and wastes between post-irradiation test facilities, FMF (Fuel Monitoring Facility), AGF (Alpha Gamma Facility), and MMF (Material Monitoring Facility) at the Oarai Engineering Center, PNC. The test facilities are connected with the JOYO plant, an experimental fast reactor being constructed at Oarai. As introductory remarks, some special features of transferring irradiated materials are described. In the second part, problems on the management of nuclear materials and radio isotopes are described item by item. In the third part, the specific materials that are envisaged to be transported between JOYO and the test facilities are listed together with their geometrical shapes, dimensions, etc. In the fourth part, various routes and methods of transportation are explained with many block charts and figures. Brief explanation with lists and drawings is also given to transportation casks and vessels. Finally, some future problems are discussed, such as the prevention of diffusive contamination, ease of decontamination, and the identification of test samples. (Aoki, K.)

Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

International Nuclear Information System (INIS)

Inamura, Patricia Y.; Mastro, Nelida L. del

2015-01-01

Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s -1 , energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

Energy Technology Data Exchange (ETDEWEB)

Inamura, Patricia Y.; Mastro, Nelida L. del, E-mail: pinamura@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s{sup -1}, energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

Effectiveness of thermoluminescence analysis to detect low quantity of gamma-irradiated component in non-irradiated mushroom powders

International Nuclear Information System (INIS)

Akram, Kashif; Ahn, Jae-Jun; Shahbaz, Hafiz Muhammad; Jo, Deokjo; Kwon, Joong-Ho

2013-01-01

Gamma-irradiated (0–10 kGy) dried mushrooms (Lentinus edodes) powders were mixed at different ratios (1–10%) in the non-irradiated samples and investigated using photostimulated-luminescence (PSL), electron spin resonance (ESR) and thermoluminescence (TL) techniques. The PSL results were negative for all samples at 1% mixing ratio, whereas intermediate results were observed for the samples containing 5% or 10% irradiated component with the exception (positive) of 10% mixing of 10 kGy-irradiated sample. The ESR analysis showed the presence of crystalline sugar radicals in the irradiated samples but the radiation-specific spectral features were absent in the mixed samples. TL analysis showed the radiation-specific TL glow curves; however, the complicated results were observed at 1% mixing of 2 and 5 kGy-irradiated samples, which required careful evaluations to draw the final conclusion about the irradiation status of the samples. TL ratios could only confirm the results of samples with 5% and 10% mixing of 10 kGy, and 10% mixing of 5 kGy-irradiated components. SEM-EDX analysis showed that feldspar and quartz were major contaminating minerals, responsible for the radiation-specific luminescence characteristics. -- Highlights: ► Detection of irradiated food is important to enforce the applied regulations. ► The effectiveness of TL analysis was investigated to detect irradiated component. ► The TL results were compared with those from PSL and ESR analysis. ► TL analysis was most effective to characterize the irradiation status of samples. ► SEM-EDX analysis showed feldspar and quartz as the main source of TL properties

Effectiveness of thermoluminescence analysis to detect low quantity of gamma-irradiated component in non-irradiated mushroom powders

Energy Technology Data Exchange (ETDEWEB)

Akram, Kashif [School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Institute of Food Science and Nutrition, University of Sargodha, Sargodha 40100 (Pakistan); Ahn, Jae-Jun [School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Shahbaz, Hafiz Muhammad [School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Institute of Food Science and Nutrition, University of Sargodha, Sargodha 40100 (Pakistan); Jo, Deokjo [School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kwon, Joong-Ho, E-mail: jhkwon@knu.ac.kr [School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

2013-04-15

Gamma-irradiated (0–10 kGy) dried mushrooms (Lentinus edodes) powders were mixed at different ratios (1–10%) in the non-irradiated samples and investigated using photostimulated-luminescence (PSL), electron spin resonance (ESR) and thermoluminescence (TL) techniques. The PSL results were negative for all samples at 1% mixing ratio, whereas intermediate results were observed for the samples containing 5% or 10% irradiated component with the exception (positive) of 10% mixing of 10 kGy-irradiated sample. The ESR analysis showed the presence of crystalline sugar radicals in the irradiated samples but the radiation-specific spectral features were absent in the mixed samples. TL analysis showed the radiation-specific TL glow curves; however, the complicated results were observed at 1% mixing of 2 and 5 kGy-irradiated samples, which required careful evaluations to draw the final conclusion about the irradiation status of the samples. TL ratios could only confirm the results of samples with 5% and 10% mixing of 10 kGy, and 10% mixing of 5 kGy-irradiated components. SEM-EDX analysis showed that feldspar and quartz were major contaminating minerals, responsible for the radiation-specific luminescence characteristics. -- Highlights: ► Detection of irradiated food is important to enforce the applied regulations. ► The effectiveness of TL analysis was investigated to detect irradiated component. ► The TL results were compared with those from PSL and ESR analysis. ► TL analysis was most effective to characterize the irradiation status of samples. ► SEM-EDX analysis showed feldspar and quartz as the main source of TL properties.

Sensitivity of bacteria to photoactivated titanium dioxide in comparison with UV irradiation

International Nuclear Information System (INIS)

Kersters, Ilse; De Keyser, Tilly; Verstraete, Willy

1998-01-01

Titanium dioxide was used as a photocatalyst to generate hydroxyl radicals in a flowthrough water reactor. Experiments were performed with cultures of Aeromonas hydrophila AWWX1 and Pseudomonas fluorescens R 2 f to evaluate the disinfection capabilities of the reactor. Although a decrease in viable counts was observed with long-wavelength (λ=370 nm) irradiated TiO 2 pellets, direct UV 254 irradiation seems a superior technology for the disinfection of transparent potable water since the viable counts of the test strains declined stronger (2-5 logs) and faster (20x) in UV 254 -treated water than in photoactivated TiO 2 -treated water. Outdoor tests conducted in the summer noonday sun showed that the viable counts of Aeromonas hydrophila AWWX1 decreased strongly (ca 5 log units) in transparent and turbid water samples (750 NTU) exposed to natural sunlight (47,000 lux). The addition of TiO 2 to the solar irradiated waters did not influence the die-off of the strain. These observations indicate that the photocatalytic approach does not offer real prospects as an alternative technology for the disinfection of drinking water. (author)

Effects of nickel on irradiation embrittlement of light water reactor pressure vessel steels

International Nuclear Information System (INIS)

2005-06-01

This TECDOC was developed under the IAEA Coordinated Research Project (CRP) entitled Effects of Nickel on Irradiation Embrittlement of Light Water Reactor Pressure Vessel (RPV) Steels. This CRP is the sixth in a series of CRPs to determine the influence of the mechanism and quantify the influence of nickel content on the deterioration of irradiation embrittlement of reactor pressure vessel steels of the Ni-Cr-Mo-V or Mn-Ni-Cr-Mo types. The scientific scope of the programme includes procurement of materials, determination of mechanical properties, irradiation and testing of specimens in power and/or test reactors, and microstructural characterization. Eleven institutes from eight different countries and the European Union participated in this CRP and six institutes conducted the irradiation experiments of the CRP materials. In addition to the irradiation and testing of those materials, irradiation experiments of various national steels were also conducted. Moreover, some institutes performed microstructural investigations of both the CRP materials and national steels. This TECDOC presents and discusses all the results obtained and the analyses performed under the CRP. The results analysed are clear in showing the significantly higher radiation sensitivity of high nickel weld metal (1.7 wt%) compared with the lower nickel base metal (1.2 wt%). These results are supported by other similar results in the literature for both WWER-1000 RPV materials, pressurized water reactor (PWR) type materials, and model alloys. Regardless of the increased sensitivity of WWER-1000 high nickel weld metal (1.7 wt%), the transition temperature shift for the WWER-1000 RPV design fluence is still below the curve predicted by the Russian code (standard for strength calculations of components and piping in NPPs - PNAE G 7-002-86). For higher fluence, no data were available and the results should not be extrapolated. Although manganese content was not incorporated directly in this CRP

Decomposition of colored wastewater for recycling water by gamma-ray irradiation

International Nuclear Information System (INIS)

Tanabe, Hiroko; Sekiguchi, Masayuki; Sawai, Teruko

1995-01-01

Utilization of advanced treated water from wastewater treatment plants for the restoration of waterway is in progress to improve the waterside environment. However, the colored wastewater containing molasses pigments, melanoidins, is not decolorized by activated sludge process, and the water can not be applied for recycling water. We have studied the radiation treatment for decolorization of wastewater discharged from baker's yeast factory. The decolorization after decomposition of colored biorefractory organic substances in wastewater, enhancement in biodegradability and effective decrease in values of COD were observed after gammaray irradiation. Although the decrease in values of COD was observed, however chromaticity was not improved after the combined treatment of wastewater by radiation together with activated sludge. The result suggests that it is necessary to find the optimum conditions for stimulation of sludge in the combined treatment. (author)

Irradiation of spices produced in Argentina

International Nuclear Information System (INIS)

Kairiyama, E.; Narvaiz, P.; Lescano, G.; Kaupert, N.L.

1988-01-01

Some spices produced in Argentina ground red pepper, anise, fennel, laurel, paprika, Cayenne pepper, cumin (seed), and mayoram (leaves and flowers), were irradiated to inactivate microbial lead, without causing significant chemical or sensory alterations. They were packed in polyethylene bags of 100 m thickness, and irradiated at the 60 Co semi-industrial facility of the Ezeiza Atomic Center, with doses of 7 and 10 kGy, and dose rate of 93.87 Gy/min. Dosimetric data were evaluated with potassium nitrate. Control and irradiated samples were stored at room temperature. Chemical analysis were performed to verify the Argentine Alimentary Codex specifications: water content; essence; total ash; ash insoluble in acid; alcoholic, volatile ether and non-volatile ether extracts; starch; and crude fiber. Besides, colour and volatile substances were analyzed. No differences were found between control and irradiated samples, with the exception of an increase in the total amount of volatiles released by irradiated spices, and a slight colour loss in mayoram. Microbiological determinations consisted of aerobic plate count, yeasts and moulds, coliform bacteria, Salmonella, Staphylococcus aureus, mesophilic and thermophilic sporeformers, enterococci and Clostridium perfringens. Microbial load in control samples oscillated between 10 3 and 10 6 microorganisms per gram, and was inhibited with 10 kGy to undetectable level. With 7 kGy, survivors were still detected in: cumin, anise, laurel, red pepper, fennel and paprika. So, the purpose of this work was accomplished with the dose of 10 kGy. Great improvement on the quality of those products which being stored at room temperature are consumed in the raw state, would be attained. (Author) [es

Extractable proteins from electron beam (EB) irradiated natural rubber (NR) latex

International Nuclear Information System (INIS)

Feroza Akhtar; Fumio Yoshii; Keizo Makuuchi

1996-01-01

The protein assay of natural rubber latex (NRL) vulcanized by low energy electron beam (EB, 300 keV, 30 mA) has been carried out using Bicinchoninic acid (BCA) reagent. Extractable protein in irradiated latex film was determined by measuring the absorption of colored solution at 562 nm using UV spectrometer. The effect of various radiation doses on the extractable protein content of NRL was investigated. It was ,found that the quantities of extractable protein increases with radiation dose. When compared with ,gamma-ray irradiated samples the same trend was observed. Electron beam irradiated latex films are leached in 1% (ammonia water for various lengths of time. From the results it was established that within 2 hours of leaching in ammonia water most of the extractable protein (96%) were removed from rubber film

Water and sewage sludge disinfection by irradiation. Pt. 4 and 5

International Nuclear Information System (INIS)

Alexandre, D.

1978-01-01

Estimation of cost shows that water disinfection by irradiation is too expensive. Liquid wastes can be treated by low and medium energy accelerators but they are competitive with thermal process only for large installations. Dry sludges can be treated by radioelements, energy saving is important with gamma ray sources, this process is cheaper especially for small installations, results with high energy accelerators are encouraging for dry sludges and large installations [fr

Investigation of hydrogen isotopes interaction processes with lithium under neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Zaurbekova, Zhanna, E-mail: zaurbekova@nnc.kz [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Skakov, Mazhyn; Ponkratov, Yuriy; Kulsartov, Timur; Gordienko, Yuriy; Tazhibayeva, Irina; Baklanov, Viktor; Barsukov, Nikolay [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Chikhray, Yevgen [Institute of Experimental and Theoretical Physics of Kazakh National University, Almaty (Kazakhstan)

2016-11-01

Highlights: • The experiments on study of helium and tritium generation and release processes under neutron irradiation from lithium saturated with deuterium are described in paper. ​ • The values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation is calculated. • It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide. - Abstract: The paper describes the experiments on study of helium and tritium generation and release processes from lithium saturated with deuterium under neutron irradiation (in temperature range from 473 to 773 K). The diagrams of two reactor experiments show the time dependences of helium, DT, T{sub 2}, and tritium water partial pressures changes in experimental chamber with investigated lithium sample. According to experimental results, the values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation were calculated. The time dependences of relative tritium and helium yield from lithium sample were plotted. It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide.

Gamma-irradiation effect on a commercial composite anticorrosive pigment and acidity-to-alkalinity conversion

Science.gov (United States)

Song, Weiqiang; Niu, Kaihui; Wu, Longchao

2016-05-01

A commercial composite anticorrosive pigment based on aluminum dihydrogen tripolyphosphate was studied after exposure to gamma irradiation (Co60, 0, 20, 50, 100 and 150 kGy) using FTIR, XRD, TGA and acid-base titration technologies. Although the FTIR spectra showed that the effect of the irradiation on functional groups in the pigments was not obvious, the decrease in the crystal lattice parameters of the irradiated pigments was observed in the XRD spectra compared to the non-irradiated sample. But the extent of the lattice parameter decrease monotonically with the increase of absorbed dose from 20 to 150 kGy, which was attributed to the decomposition of water and the simultaneous occurrence of lattice damage when the pigments were exposed to gamma rays. Of particular significance was the displayed basicity of the aqueous solutions of the irradiated pigments compared to the acidity of the solution of the non-irradiated pigment, which was attributed to the decomposition of P-OH groups (combined water).

Measuring the critical current in superconducting samples made of NT-50 under pulse irradiation by high-energy particles

International Nuclear Information System (INIS)

Vasilev, P.G.; Vladimirova, N.M.; Volkov, V.I.; Goncharov, I.N.; Zajtsev, L.N.; Zel'dich, B.D.; Ivanov, V.I.; Kleshchenko, E.D.; Khvostov, V.B.

1981-01-01

The results of tests of superconducting samples of an uninsulated wire of the 0.5 mm diameter, containing 1045 superconducting filaments of the 10 μm diameter made of NT-50 superconductor in a copper matrix, are given. The upper part of the sample (''closed'') is placed between two glass-cloth-base laminate plates of the 50 mm length, and the lower part (''open'') of the 45 mm length is immerged into liquid helium. The sample is located perpendicular to the magnetic field of a superconducting solenoid and it is irradiated by charged particle beams at the energy of several GeV. The measurement results of permissible energy release in the sample depending on subcriticality (I/Isub(c) where I is an operating current through the sample, and Isub(c) is a critical current for lack of the beam) and the particle flux density, as well as of the maximum permissible fluence depending on subcriticality. In case of the ''closed'' sample irradiated by short pulses (approximately 1 ms) for I/Isub(c) [ru

Bakery products from irradiated and non-irradiated eggs - analytical problems associated with the detection of irradiation in processed foods

International Nuclear Information System (INIS)

Grabowski, H.U. von; Pfordt, J.

1993-01-01

In spring and early summer 1992, a number of irradiated egg products were illegally imported into Germay. To prove the irradiation of these egg products, mainly combined gas chromatography-mass spectrometry was applied. With this present study we wanted to answer the question if we were also able to detect the use of irradiated eggs in processed foods. The processed food we chose to produce and to investigate was a tart layer. For this product, dilution effects are of minor importance as no extra fat was added. Thus, the layers' fat almost exclusively came from the eggs. To study the influence of emulsifiers, we produced batters both with and without adding an emulsifer. The unsaturted hydrocarbons C14:1, C16:3, C16:2, C17:2, and C17:1 served as markers for an irradiation. In the non-irradiated egg samples and in the tart layers produced from them, these compounds could not be detected (or in some cases only in small amounts). They were, however, detectable in all irradiated samples. DCB could be found in all irradiated egg samples and in the tart layers that were baked from irradiated eggs. It was not present in non-irradiated eggs and in tart layers produced from them. (orig./Vhe)

Delayed match-to-sample early performance decrement in monkeys after 60Co irradiation

International Nuclear Information System (INIS)

Bruner, A.; Bogo, V.; Jones, R.K.

1975-01-01

Sixteen monkeys were trained on a delayed match-to-sample task (DMTS) based on shock avoidance and irradiated with single, whole-body exposures of from 396 to 2000 rad 60 Co (midbody dose) at between 163 and 233 rad/min. Pre- to post-irradiation performance changes were assessed using a penalty-scaling measure which differentially weighted incorrect responses, response omissions, and error-omission sequences. Thirteen of the animals displayed early performance decrement, including five incapacitations, at lower doses (less than 1000 rad) than heretofore found effective. This was considered a function of task complexity, measurement sensitivity, and gamma effectiveness. The minimum effective midbody dose for inducing decrement using the DMTS task was estimated to be on the order of 500 rad. The nature of early, transient performance decrement seems to reflect more of an inability to perform than an inability to perform correctly

Investigation on improvement of properties of polyethylene by γ-irradiation(1)

International Nuclear Information System (INIS)

Cho Sang Gyu; Chong Yong Mu; Li In Son.

1984-01-01

The change in properties and structure of low-density polyethylene(PEt) caused by γ-irradiation and the influence of the media such as air, vacuum, nitrogen and water on it at the absorption dose from 0 to 1MGy were investigated. By measuring solubility, molecular weight, gel-fraction and swelling degree of the radiated samples, crosslinking of PEt was determined, on the basis of it the relative efficiency of irradiation media was estimated. It was proved that the irradiation crosslinking of PEt in the air medium is not possible, and that water is a best medium for the irradiation crosslinking. By means of IR spectroscopy the change in amorphous content (absorption increase at 1300cm -1 and 1375cm -1 ), the increase of trans-vinylene content (at 946cm -1 ), and the decrease of vinyl (at 908cm -1 ) and vinylidene content were confirmed and the chemical reaction mechanism of the radiation modification was suggested. (author)

The Effect of UVC Irradiation on the Mechanical Properties of Chitosan Membrane in Sterilization Process

Science.gov (United States)

Rupiasih, N. N.; Sumadiyasa, M.; Putra, I. K.

2018-04-01

The present study, we report about the effect of UVC irradiation on the mechanical properties of chitosan membrane in the sterilization process. The membrane used was chitosan membrane 2% which prepared by a casting method using chitosan as matrix and acetic acid 1% as a solvent. The UVC source used was germicidal ultraviolet (UVG) which widely used for sterilization purposes. Variation doses were done by the varying time of irradiation, e.g. 5 min, 15 min, 30 min, and 60 min. Those samples are named as S1, S2, S3, and S4, respectively. Chitosan membrane before irradiation namely S0 also used for comparative study. The effect of UVC irradiation on the mechanical properties of membranes has been examined by different techniques including FTIR, DMA, and the water uptake capability. The results showed that ultimate tensile strength (UTS) and moduli of elasticity (E) were increased by increasing the irradiation time. From FTIR analysis obtained that no new molecules were formed in irradiated membranes. The water uptakes capability of the membranes after irradiation was smaller compared with before irradiation, and among the irradiated membranes, the water uptake capabilities were increased by increasing the exposure time. These observations suggested that more care should be taken during the sterilization process and outdoor used of the membrane. The other side, the UVC irradiation can improve the mechanical properties of the membranes.

The effects of gamma irradiation on medicinal plants and spices (3), Curcuma xanthoriza, curcuma aeruginosa, curcuma domestica and kaemferia galanga

International Nuclear Information System (INIS)

Chosdu, Rahayu; Hilmy, Nazly; Bagiawati, Sri

1985-01-01

This research was conducted to investigate the effects of gamma irradiation on medicinal plants by studying the characteristics of the essential oils of these samples. The samples studied were ''temu lawak'' (Curcuma xanthoriza), ''temu hitam'' (Curcuma aeruginosa), turmeric (Curcuma domestica) and galanga (Kaemferia galanga). The sliced tubers, which contained 8 to 14% of moisture were packed in low density polyethylene bags of 0.13 mm thickness, then irradiated with doses of 0, 5 and 10 kGy. Some samples were directly analyzed and the rest were stored for six months at temperatures of 29±2 0 C and under 70 to 95% humidity. The results showed that the water activity (Aw), the content and characteristics of essential oils, analyzed on a gas liquid chromatography, were not changed by irradiation and storage, but the water content was changed by storage. It was observed also that after irradiation and storage mould and bacteria contents decreased. (author)

Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation

Energy Technology Data Exchange (ETDEWEB)

Maehara, Tsunehiro, E-mail: maehara@phys.sci.ehime-u.ac.jp [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Nishiyama, Kyohei; Onishi, Shingo; Mukasa, Shinobu; Toyota, Hiromichi [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kuramoto, Makoto [Integrated Center for Science, Ehime University, Matsuyama 790-8577 (Japan); Nomura, Shinfuku [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kawashima, Ayato [Faculty of Agriculture, Ehime University, Matsuyama 790-8566 (Japan)

2010-02-15

The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor lamp enhanced degradation significantly. A lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.

Preconcentration NAA for simultaneous multielemental determination in water sample

International Nuclear Information System (INIS)

Chatt, A.

1999-01-01

Full text: Environment concerns with water, air, land and their interrelationship viz., human beings, fauna and flora. One of the important environmental compartments is water. Elements present in water might face a whole lot of physico-chemical conditions. This poses challenges to measure their total concentrations as well as different species. Preconcentration of the elements present in water samples is a necessary requisites in water analysis. For multi elements concentration measurements, Neutron Activation Analysis (NAA) is one of the preferred analytical techniques due to its sensitivity and selectivity. In this talk preconcentration NAA for multielemental determination in water sample determination will be discussed

Application of electron beam technology in improving sewage water ...

African Journals Online (AJOL)

user

irradiation sewage water can find its application either in agriculture for irrigation or in industry sector for cooling ... The water samples were collected from sewage water treatment .... to be irrigated, soil conditions and the irrigation system.

Devices for irradiation of materials in the fast neutron flux at the RA heavy water reactor in Vinca; Uredjaji za ozracivanje materijala u fluksu brzih neutrona na teskovodnom reaktoru RA u Vinci

Energy Technology Data Exchange (ETDEWEB)

Pavicevic, M [Institut za nuklearne nauke Boris Kidric, Vinca, Beograd (Yugoslavia)

1964-07-01

Full text: This paper covers the concept, technical description and problems of constructing special experimental facilities at the RA reactor in Vinca. During 1962, construction materials (graphite, Mg, Al-oxides, steel and Zircaloy) were irradiated in these facilities at temperatures below 100 deg C by the integral fast neutron flux of 2 10{sup 20} n/cm{sup 2}. Temperature of the samples cooled by heavy water circulating through hollow uranium elements was measured by thermocouples. Construction of the facility, sample preparation, related measurements of the flux and irradiation of the samples were done in cooperation with the Nuclear center in Saclay, France. A short review of the experiences in using the new experimental space at the RA reactor is given, together with some problems related to transport of radioactive capsules containing samples from Vinca to Saclay.

Study of boron carbide evolution under neutron irradiation

International Nuclear Information System (INIS)

Simeone, D.

1999-01-01

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

[Detection of Cryptospordium spp. in environmental water samples by FTA-PCR].

Science.gov (United States)

Zhang, Xiao-Ping; Zhu, Qian; He, Yan-Yan; Jiang, Li; Jiang, Shou-Fu

2011-02-01

To establish a FTA-polymeras chain reaction (FTA-PCR) method in detection of Cryptospordium spp. in different sources of water. The semi automated immunomagnetic separation (IMS) of Cryptospordium oocysts in environmental water samples was performed firstly, and then genomic DNA of Cryptospordium oocysts was extracted by FTA filters disk. Oligonucleotide primers were designed based on the DNA fragment of the 18 S rRNA gene from C. parvum. Plate DNA was amplified with primers in PCR. The control DNA samples from Toxoplasma gondii,Sarcocystis suihominis, Echinococcus granulosus, and Clonorchis sinensis were amplified simultaneously. All PCR products were detected by agar electrophoresis dyed with ethidium bromide. The 446 bp fragment of DNA was detected in all samples of C. parvum, C. andersoni, and C. baileyi, while it was not detected in control groups in laboratory. No positive samples were found from 10 samples collected from tape water in 5 districts of Shanghai City by FTA-PCR. Nine positive samples were detected totally from 70 different environmental water samples, there were 0 out of 15 samples from the source of tape water, 2 out of 25 from the Huangpu River, 5 out of 15 from rivers around the animal farmers, 1 out of 9 from output water of contaminating water treatment factory, 1 out of 6 from the out gate of living contaminating water. The 446 bp fragment was detected from all the amplified positive water samples. FTA-PCR is an efficient method for gene detection of Cryptospordium oocysts, which could be used in detection of environmental water samples. The contamination degree of Cryptospordium oocysts in the river water around animal farms is high.

ATTENUATION OF THE DISRUPTIVE EFFECTS INDUCED BY GAMMA IRRADIATION IN RATS USING OZONATED WATER AND/OR TAURINE

International Nuclear Information System (INIS)

HEIBASHY, M.I.A.; SHAROUD, M.N.M.

2008-01-01

People can be exposed to irradiation either external or internal. The potential for health effects depends in part on the radiation dose delivered, the rate of delivery and where in the body particular radionuclides are concentrated. All radionuclides are partly absorbed from the lung and intestinal tract into the blood stream causing oxidation and free radical formation.In the first experiment, the data showed that the ionizing radiation induced a significant increment in the levels of serum glucose and lipid profile (cholesterol, triglycerides, HDL and LDL) and elevation in the activities of both serum AST and ALT. On the other hand, the ionizing radiation induced a significant decline in the concentrations of serum insulin, total protein, albumin and free T 3 while no remarkable change was occurred on the level of free T 4 . In case of exposing rat to gamma ray, both liver GSH and GPx activities were decreased while the level of liver TBARS was significantly elevated as compared to the corresponding normal control group.In the second experiment, a significant correction was occurred in all previous parameters after the irradiated rats were treated with taurine (500 mg/100g body weight/ day for one month) while the irradiated rats which received ozonated water showed no remarkable changes in the levels of estimated parameters. The best amelioration effect was occurred in the previous parameters in irradiated rats which were treated with both taurine and ozone (ozonated water) for one month.It could be concluded that taurine is considered as a radio-protector agent while ozone (ozonated water) acts as co-radioprotector agent when the irradiated animals are treated by a mixture of those agents

Effects of irradiation and heating on extraction of carbohydrates from brown seaweed, gagome Kjellmaniella crassifolia

International Nuclear Information System (INIS)

Suzuki, T.; Yoshie, Y.; Shirai, T.; Hirano, T.

1993-01-01

Changes in dissolved carbohydrates from Gagome Kjemaniella crassifolia by gamma-irradiation and boiling were investigated. When pulverized Gagome was irradiated in the dry state, solubilized carbohydrate levels did not change at dose levels up to 50 kGy; however, the molecular weights of main components in the soluble matter decreased. The amount of dissolved carbohydrates increased with dosage increments of gamma rays when irradiated in water, and their molecular weights decreased markedly. When Gagome was irradiated with a dose of 10 kGy in the dry state, and then boiled in water, the amounts of carbohydrates dissolved were markedly high at 80 degree C during 10-h boiling in comparison with those of the non-irradiated control. On the other hand, at 100 degree C no difference was observed after 4-h boiling. There was no significant difference in the quantity of dissolved carbohydrates or their molecular weights between irradiated and non-irradiated samples heated at 120 degree C for up to 12 h. From these results dietary fibers in Gagome were found to be extracted and degradated by irradiation

Progress on using deuteron-deuteron fusion generated neutrons for 40Ar/39Ar sample irradiation