Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature

International Nuclear Information System (INIS)

Hlatshwayo, T T; Kuhudzai, R J; Njoroge, E G; Malherbe, J B; O’Connell, J H; Skuratov, V A; Msimanga, M

2015-01-01

The effect of swift heavy ion (Xe 167 MeV) irradiation on polycrystalline SiC individually implanted with 360 keV Kr and Xe ions at room temperature to fluences of 2  ×  10 16 cm −2 and 1  ×  10 16 cm −2 respectively, was investigated using transmission electron microscopy (TEM), Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Implanted specimens were each irradiated with 167 MeV Xe +26 ions to a fluence of 8.3  ×  10 14 cm −2 at room temperature. It was observed that implantation of 360 keV Kr and Xe ions individually at room temperature amorphized the SiC from the surface up to a depth of 186 and 219 nm respectively. Swift heavy ion (SHI) irradiation reduced the amorphous layer by about 27 nm and 30 nm for the Kr and Xe samples respectively. Interestingly, the reduction in the amorphous layer was accompanied by the appearance of randomly oriented nanocrystals in the former amorphous layers after SHI irradiation in both samples. Previously, no similar nanocrystals were observed after SHI irradiations at electron stopping powers of 33 keV nm −1 and 20 keV nm −1 to fluences below 10 14 cm −2 . Therefore, our results suggest a fluence threshold for the formation of nanocrystals in the initial amorphous SiC after SHI irradiation. Raman results also indicated some annealing of radiation damage after swift heavy ion irradiation and the subsequent formation of small SiC crystals in the amorphous layers. No diffusion of implanted Kr and Xe was observed after swift heavy ion irradiation. (paper)

Work climate and work load measurement in production room of Batik Merak Manis Laweyan

Science.gov (United States)

Suhardi, Bambang; Simanjutak, Sry Yohana; Laksono, Pringgo Widyo; Herjunowibowo, Dewanto

2017-11-01

The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that the workplace climate and the workload at eight stations in production room of Merak Manis does not agree to the threshold limit value that has been set. Therefore, it is recommended to add more opening windows to add air velocity inside the building thus the humidity and temperature might be reduced.

Influences of scattering radiation in a TLD irradiation room, 2

International Nuclear Information System (INIS)

Suzuki, Osamu; Suwa, Shigeo

1985-01-01

The influence of scattering radiation (SR) on radiation dose rate (DR) in a TLD irradiation room was assessed. A single SD from a standard TLD apparatus, i.e., an acrylic or aluminum table, was examined. The maximum DR was attained at approximately 80 cm from the radiation source. Energy spectra of SR ranged up to the energy of direct radiation beam. Circular SD at one m from the radiation source, which contributed to DR to the direct radiation beam, was almost homogeneous. SD was large near the irradiation table, and the influence of SD on DR became smaller with SD being vertically farther from the apparatus. The influence of SD on RD to the direct radiation beam became less with an increase in gamma ray energy. At one m from the radiation source, 6 - 7 % of SD contributed to DR to the direct radiation beam for 0.662 MeV of gamma ray. This figure was one half of that with NaI (Tl) scintillation detector. (Namekawa, K.)

Investigation of room temperature UV emission of ZnO films with different defect densities induced by laser irradiation.

Science.gov (United States)

Zhao, Yan; Jiang, Yijian

2010-08-01

We studied the room temperature UV emission of ZnO films with different defect densities which is fabricated by KrF laser irradiation process. It is shown room temperature UV photoluminescence of ZnO film is composed of contribution from free-exciton (FX) recombination and its longitudinal-optical phonon replica (FX-LO) (1LO, 2LO). With increase of the defect density, the FX emission decreased and FX-LO emission increased dramatically; and the relative strengths of FX to FX-LO emission intensities determine the peak position and intensity of UV emission. What is more, laser irradiation with moderate energy density could induce the crystalline ZnO film with very flat and smooth surface. This investigation indicates that KrF laser irradiation could effectively modulate the exciton emission and surface morphology, which is important for the application of high performance of UV emitting optoelectronic devices. Copyright 2010 Elsevier B.V. All rights reserved.

Mechanical properties of polymer matrix composites at 77 K and at room temperature after irradiation with 60Co γ-rays

International Nuclear Information System (INIS)

Egusa, S.; Hagiwara, M.

1986-01-01

Ten different polymer matrix composites were irradiated with 60 Co γ-rays at room temperature, and were examined with regard to the mechanical properties at 77 K and at room temperature. The radiation resistance of these composites depends primarily on the radiation resistance of matrix resins, which increases in the order diglycidyl ether of bisphenol A < tetraglycidyl diaminodiphenyl methane < Kerimid 601. Comparison of the mechanical properties tested at 77 K and at room temperature demonstrates that the extent of radiation-induced decrease in the composite strength is appreciably greater in the 77 K test than in the room temperature test. (author)

Software Design of SMD LEDs for Homogeneous Distribution of Irradiation in the Model of Dark Room

Directory of Open Access Journals (Sweden)

Andrej Liner

2014-01-01

Full Text Available This article describes wireless optical data networks using visible spectra of optical radiation with a focus on interior areas with direct line of sight LOS (line-of-sight. This type of network represents progressively evolving area of information technologies. Development of lightning technologies based on white power LED was the impulse for wireless optical data networks based on visible spectra of optical radiation (VLC development. Its basic advantage is the flexibility of users. Users don’t have to stay on one place during the data sharing anymore. Wireless optical data networks represent an alternative solution for metallic and fiber networks [1], [2]. This paper deals with the software simulation of homogeneous distribution of optical irradiation in dark room model, carrying out in LightTools software. First, in previous simulations, the optical source composed from 9 SMD LED’s type LW G6SP-EAFA-JKQL-1 was designed. In various simulations, various numbers and distributions of LED’s were used. These were placed at the ceiling of the dark room. At last, the results of optical irradiation homogeneity are compared.

Impact of Room Location on UV-C Irradiance and UV-C Dosage and Antimicrobial Effect Delivered by a Mobile UV-C Light Device.

Science.gov (United States)

Boyce, John M; Farrel, Patricia A; Towle, Dana; Fekieta, Renee; Aniskiewicz, Michael

2016-06-01

OBJECTIVE To evaluate ultraviolet C (UV-C) irradiance, UV-C dosage, and antimicrobial effect achieved by a mobile continuous UV-C device. DESIGN Prospective observational study. METHODS We used 6 UV light sensors to determine UV-C irradiance (W/cm2) and UV-C dosage (µWsec/cm2) at various distances from and orientations relative to the UV-C device during 5-minute and 15-minute cycles in an ICU room and a surgical ward room. In both rooms, stainless-steel disks inoculated with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and Clostridium difficile spores were placed next to sensors, and UV-C dosages and log10 reductions of target organisms achieved during 5-minute and 15-minute cycles were determined. Mean irradiance and dosage readings were compared using ANOVA. RESULTS Mean UV-C irradiance was nearly 1.0E-03 W/cm2 in direct sight at a distance of 1.3 m (4 ft) from the device but was 1.12E-05 W/cm2 on a horizontal surface in a shaded area 3.3 m (10 ft) from the device (P4 to 1-3 for MRSA, >4 to 1-2 for VRE and >4 to 0 log10 for C. difficile spores, depending on the distance from, and orientation relative to, the device with 5-minute and 15-minute cycles. CONCLUSION UV-C irradiance, dosage, and antimicrobial effect received from a mobile UV-C device varied substantially based on location in a room relative to the UV-C device. Infect Control Hosp Epidemiol 2016;37:667-672.

Instrumented indentation for characterization of irradiated metals at room and high temperatures

International Nuclear Information System (INIS)

Sacksteder, Irene

2011-01-01

The reliability and sustainability of future fusion power plants will highly depend on the aptitude of materials to withstand severe irradiation conditions induced by the burning plasma in reactors. The so-called reduced-activation ferritic-martensitic (RAFM) steels are the current promising candidates for the structural applications considering the reactor's first wall. These steels exhibit irradiation embrittlement and hardening for defined irradiation conditions that are mainly characterized by the irradiation temperature and the irradiation dose. A proper characterization of such irradiated steels implies the use of adapted mechanical testing tools. In the present study, the instrumented indentation technique makes use of a post-processing tool based on neural networks. This technique has been selected for its ability to examine tensile properties by multistage indents on miniaturized irradiated metallic samples. The steel specimens studied in this project have been neutron-irradiated up to a dose of 15 dpa. They have been subsequently tested at room temperature in a Hot Cell by means of an adapted commercial indentation device. The significant irradiation-induced hardening effect present in the range of 250-350 deg C could be observed in the hardness and material's strength parameters. These two material parameters show a similar evolution with increasing irradiation temperatures. Post-irradiation annealing treatments of Eurofer97 have been realized and leads to a partial recovery of the irradiation damage. Considering the demands for characterization in irradiated steels at high temperature and for post-irradiation annealing experiments, the existing instrumented indentation device has been further developed during this work. A conceptual design has been proposed for an indentation testing machine, operating at up to 650 deg C, while remaining the critical temperature limit for tensile strength of the newly developed oxide dispersion strengthening ferritic

A study of the physiological changes and the nutritional qualities of irradiated apples and the effect of irradiation on apples stored at room temperature

International Nuclear Information System (INIS)

Wang Chuanyao; Jiang Mengyue; Gao Meixu; Ma Xiuye; Zhang Shufen; Liu Shucheng

1993-01-01

The effects of γ-irradiation on the metabolism and nutritional qualities of Golden Delicious apples and on the lethality of pathogenic fungi have been studied. The storage effect of irradiation on apples at room temperature has been observed. Results showed that the respiratory intensity of irradiated apple at 0.3-0.5 kGy was near or lower than that of unirradiated apple after 15 days irradiation. The amount of ethylene release was obviously inhibited when fruits were irradiated with 0.3-0.7 kGy. The flesh firmness of apples irradiated with 0.3-0.9 kGy was higher than that of unirradiated apple with increased storage time. The negative correlations between the flesh firmness and the activities of pectinesterase (PE), polygalacturonase (PG) were observed when the dosage was lower than 1.5 kGy. The 2.0 kGy irradiation damaged the ultrastructure of cells, induced the softening of apple. When apples were irradiated with 0.7-2.0 kGy, the contents of 4 important volatile components of apple would be decreased. However, this dose had no effects on the pure chemicals. Studies showed that there was no significant effect of irradiation with 0.3-2.0 kGy on the nutritional qualities of apples and this dose range could effectively control the verticillate pathogenic fungi. The result of storage experiment showed that rotting of fruits decreased by 0.3-0.9 kGy irradiation. (author)

In situ electron beam irradiated rapid growth of bismuth nanoparticles in bismuth-based glass dielectrics at room temperature

International Nuclear Information System (INIS)

Singh, Shiv Prakash; Karmakar, Basudeb

2011-01-01

In this study, in situ control growth of bismuth nanoparticles (Bi 0 NPs) was demonstrated in bismuth-based glass dielectrics under an electron beam (EB) irradiation at room temperature. The effects of EB irradiation were investigated in situ using transmission electron microscopy (TEM), selected-area electron diffraction and high-resolution transmission electron microscopy. The EB irradiation for 2–8 min enhanced the construction of bismuth nanoparticles with a rhombohedral structure and diameter of 4–9 nm. The average particle size was found to increase with the irradiation time. Bismuth metal has a melting point of 271 °C and this low melting temperature makes easy the progress of energy induced structural changes during in situ TEM observations. This is a very useful technique in nano-patterning for integrated optics and other applications.

Changes in safety climate and teamwork in the operating room after implementation of a revised WHO checklist: a prospective interventional study.

Science.gov (United States)

Erestam, Sofia; Haglind, Eva; Bock, David; Andersson, Annette Erichsen; Angenete, Eva

2017-01-01

Inter-professional teamwork in the operating room is important for patient safety. The World Health Organization (WHO) checklist was introduced to improve intraoperative teamwork. The aim of this study was to evaluate the safety climate in a Swedish operating room setting before and after an intervention, using a revised version of the WHO checklist to improve teamwork. This study is a single center prospective interventional study. Participants were personnel working in operating room teams including surgeons, anesthesiologists, scrub nurses, nurse anaesthetists and nurse assistants. The study started with pre-interventional observations of the WHO checklist use followed by education on safety climate, the WHO checklist, and non-technical skills in the operating room. Thereafter a revised version of the WHO checklist was introduced. Post-interventional observations regarding the performance of the WHO checklist were carried out. The Safety Attitude Questionnaire was used to assess safety climate at baseline and post-intervention. At baseline we discovered a need for improved teamwork and communication. The participants considered teamwork to be important for patient safety, but had different perceptions of good teamwork between professions. The intervention, a revised version of the WHO checklist, did not affect teamwork climate. Adherence to the revision of the checklist was insufficient, dominated by a lack of structure. There was no significant change in teamwork climate by use of the revised WHO checklist, which may be due to insufficient implementation, as a lack of adherence to the WHO checklist was detected. We found deficiencies in teamwork and communication. Further studies exploring how to improve safety climate are needed. NCT02329691.

Modification of embedded Cu nanoparticles: Ion irradiation at room temperature

International Nuclear Information System (INIS)

Johannessen, B.; Kluth, P.; Giulian, R.; Araujo, L.L.; Llewellyn, D.J.; Foran, G.J.; Cookson, D.J.; Ridgway, M.C.

2007-01-01

Cu nanoparticles (NPs) with an average diameter of ∼25 A were synthesized in SiO 2 by ion implantation and thermal annealing. Subsequently, the NPs were exposed to ion irradiation at room temperature simultaneously with a bulk Cu reference film. The ion species/energy was varied to achieve different values for the nuclear energy loss. The short-range atomic structure and average NP diameter were measured by means of extended X-ray absorption fine structure spectroscopy and small angle X-ray scattering, respectively. Transmission electron microscopy yielded complementary results. The short-range order of the Cu films remained unchanged consistent with the high regeneration rate of bulk elemental metals. For the NP samples it was found that increasing nuclear energy loss yielded gradual dissolution of NPs. Furthermore, an increased structural disorder was observed for the residual NPs

Safety measures in exposure room

International Nuclear Information System (INIS)

Muhammad Jamal Md Isa

2004-01-01

The contents of this chapter are follows - The exposure room: location and dimension, material and thickness, windows, doors and other openings; Position of the Irradiating Apparatus, Use of Space Adjoining the Room, Warning Signs/Light, Dark Room. Materials and Apparatus: Classification of Areas, Local Rules, Other General Safety Requirements

Oxygen vacancy-induced room-temperature ferromagnetism in D—D neutron irradiated single-crystal TiO2 (001) rutile

Science.gov (United States)

Xu, Nan-Nan; Li, Gong-Ping; Pan, Xiao-Dong; Wang, Yun-Bo; Chen, Jing-Sheng; Bao, Liang-Man

2014-10-01

Remarkable room temperature ferromagnetism in pure single-crystal rutile TiO2 (001) samples irradiated by D—D neutron has been investigated. By combining X-ray diffraction and positron annihilation lifetime, the contracted lattice has been clearly identified in irradiated TiO2, where Ti4+ ions can be easily reduced to the state of Ti3+. As there were no magnetic impurities that could contaminate the samples during the whole procedure, some Ti3+ ions reside on interstitial or substituted sites accompanied by oxygen vacancies should be responsible for the ferromagnetism.

ESR and ENDOR of free radicals in γ-irradiated single crystals of trimethoprim at room temperature

International Nuclear Information System (INIS)

Krzyminiewski, R.; Kawacka, U.; Pietrzak, J.; Erickson, R.; Lund, A.

1995-01-01

Singe crystals of trimethoprim were examined after γ-irradiation at room temperature by ESR and ENDOR spectroscopy. A radicals is formed by abstraction of a hydrogen atom from the CH 2 group of the bridge. The unpaired electron is delocalized mainly onto the trimethoxybenzyl ring. It interacts with one proton of the bridge and with two protons in the trimethoxybenzyl ring. (au) (14 refs.)

Climate response to changes in atmospheric carbon dioxide and solar irradiance on the time scale of days to weeks

International Nuclear Information System (INIS)

Cao Long; Bala, Govindasamy; Caldeira, Ken

2012-01-01

Recent studies show that fast climate response on time scales of less than a month can have important implications for long-term climate change. In this study, we investigate climate response on the time scale of days to weeks to a step-function quadrupling of atmospheric CO 2 and contrast this with the response to a 4% increase in solar irradiance. Our simulations show that significant climate effects occur within days of a stepwise increase in both atmospheric CO 2 content and solar irradiance. Over ocean, increased atmospheric CO 2 warms the lower troposphere more than the surface, increasing atmospheric stability, moistening the boundary layer, and suppressing evaporation and precipitation. In contrast, over ocean, increased solar irradiance warms the lower troposphere to a much lesser extent, causing a much smaller change in evaporation and precipitation. Over land, both increased CO 2 and increased solar irradiance cause rapid surface warming that tends to increase both evaporation and precipitation. However, the physiological effect of increased atmospheric CO 2 on plant stomata reduces plant transpiration, drying the boundary layer and decreasing precipitation. This effect does not occur with increased solar irradiance. Therefore, differences in climatic effects from CO 2 versus solar forcing are manifested within days after the forcing is imposed. (letter)

Multiple Climate States of Habitable Exoplanets: The Role of Obliquity and Irradiance

International Nuclear Information System (INIS)

Kilic, C.; Raible, C. C.; Stocker, T. F.

2017-01-01

Stable, steady climate states on an Earth-size planet with no continents are determined as a function of the tilt of the planet’s rotation axis (obliquity) and stellar irradiance. Using a general circulation model of the atmosphere coupled to a slab ocean and a thermodynamic sea ice model, two states, the Aquaplanet and the Cryoplanet, are found for high and low stellar irradiance, respectively. In addition, four stable states with seasonally and perennially open water are discovered if comprehensively exploring a parameter space of obliquity from 0° to 90° and stellar irradiance from 70% to 135% of the present-day solar constant. Within 11% of today’s solar irradiance, we find a rich structure of stable states that extends the area of habitability considerably. For the same set of parameters, different stable states result if simulations are initialized from an aquaplanet or a cryoplanet state. This demonstrates the possibility of multiple equilibria, hysteresis, and potentially rapid climate change in response to small changes in the orbital parameters. The dynamics of the atmosphere of an aquaplanet or a cryoplanet state is investigated for similar values of obliquity and stellar irradiance. The atmospheric circulation substantially differs in the two states owing to the relative strength of the primary drivers of the meridional transport of heat and momentum. At 90° obliquity and present-day solar constant, the atmospheric dynamics of an Aquaplanet state and one with an equatorial ice cover is analyzed.

Multiple Climate States of Habitable Exoplanets: The Role of Obliquity and Irradiance

Energy Technology Data Exchange (ETDEWEB)

Kilic, C.; Raible, C. C.; Stocker, T. F., E-mail: stocker@climate.unibe.ch [Climate and Environmental Physics, Physics Institute, University of Bern (Switzerland)

2017-08-01

Stable, steady climate states on an Earth-size planet with no continents are determined as a function of the tilt of the planet’s rotation axis (obliquity) and stellar irradiance. Using a general circulation model of the atmosphere coupled to a slab ocean and a thermodynamic sea ice model, two states, the Aquaplanet and the Cryoplanet, are found for high and low stellar irradiance, respectively. In addition, four stable states with seasonally and perennially open water are discovered if comprehensively exploring a parameter space of obliquity from 0° to 90° and stellar irradiance from 70% to 135% of the present-day solar constant. Within 11% of today’s solar irradiance, we find a rich structure of stable states that extends the area of habitability considerably. For the same set of parameters, different stable states result if simulations are initialized from an aquaplanet or a cryoplanet state. This demonstrates the possibility of multiple equilibria, hysteresis, and potentially rapid climate change in response to small changes in the orbital parameters. The dynamics of the atmosphere of an aquaplanet or a cryoplanet state is investigated for similar values of obliquity and stellar irradiance. The atmospheric circulation substantially differs in the two states owing to the relative strength of the primary drivers of the meridional transport of heat and momentum. At 90° obliquity and present-day solar constant, the atmospheric dynamics of an Aquaplanet state and one with an equatorial ice cover is analyzed.

A Novel Ultraviolet Irradiation Technique for Fabrication of Polyacrylamide-metal (M = Au, Pd) Nanocomposites at Room Temperature

International Nuclear Information System (INIS)

Zhou, Y.; Hao, L.Y.; Zhu, Y.R.; Hu, Y.; Chen, Z.Y.

2001-01-01

Polyacrylamide (PAM)-metal (M = gold, palladium) nanocomposites with metal nanoparticles homogeneously dispersed in the polymer matrix have been prepared via a novel ultraviolet irradiation technique at room temperature, which is based on the simultaneous occurrence of photo-reduction formation of the colloidal metal particles and photo-polymerization of the acrylamide (AM) monomer. The UV-vis absorption spectra and TEM were employed to characterize the M-PAM nanocomposites by different irradiation times. The average sizes of the colloidal gold and palladium particles dispersed in the nanocomposites were calculated by XRD patterns and TEM images. The present method may be extended to prepare other metal-polymer hybrid nanocomposite materials

Facile fabrication of high-performance InGaZnO thin film transistor using hydrogen ion irradiation at room temperature

Energy Technology Data Exchange (ETDEWEB)

Ahn, Byung Du [School of Electrical and Electronic Engineering, 50, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Jin-Seong [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, K. B., E-mail: kbchung@dongguk.edu [Division of Physics and Semiconductor Science, Dongguk University, Seoul 100-715 (Korea, Republic of)

2014-10-20

Device performance of InGaZnO (IGZO) thin film transistors (TFTs) are investigated as a function of hydrogen ion irradiation dose at room temperature. Field effect mobility is enhanced, and subthreshold gate swing is improved with the increase of hydrogen ion irradiation dose, and there is no thermal annealing. The electrical device performance is correlated with the electronic structure of IGZO films, such as chemical bonding states, features of the conduction band, and band edge states below the conduction band. The decrease of oxygen deficient bonding and the changes in electronic structure of the conduction band leads to the improvement of device performance in IGZO TFT with an increase of the hydrogen ion irradiation dose.

NOAA Climate Data Record (CDR) of Solar Spectral Irradiance (SSI), NRLSSI Version 2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This Climate Data Record (CDR) contains solar spectral irradiance (SSI) as a function of time and wavelength created with the Naval Research Laboratory model for...

An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra

NARCIS (Netherlands)

Hogewoning, S.W.; Douwstra, P.; Trouwborst, G.; Ieperen, van W.; Harbinson, J.

2010-01-01

Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner. Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra. Whereas specific responses of plants to a

Effects of gamma irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB)

International Nuclear Information System (INIS)

Martineli, Maristella; Coneglian, Regina C.C.; Vasconcellos, Marco A.S.; Silva, Eduardo; Rocha, Janielio G.; Melo, Maruzanete P.; Vital, Helio C.

2009-01-01

Banana is a highly perishable climacteric fruit. In order to ensure fast and homogeneous ripening that will make its processing and commercialization easier, it is usually treated by climatization. On the other hand, irradiation is an interesting physical process capable of delaying ripening and extending the shelf life of fruits. This work investigated the competing effects of irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB). All fruits were harvested in the preclimacteric stage, rinsed and stored at 27 deg C after being submitted to five different treatments. After hygienization, four out of five samples were exposed to gamma-ray at doses of 0.25 and 0.50 kGy. The unirradiated fruits were left for control and half of the irradiated samples were then climatized by exposure to CaC 2 . Measurements of fresh mass loss, total soluble solids, peel coloration and disease index were performed on five different dates for up to nine days in order to monitor quality and the degree of ripening. It was found that high temperatures prevailing during climatization and storage accelerated maturation in all fruits in spite of the use of irradiation, with the control becoming ripe in 3 days only. In addition, based on the consistent results from the experiments performed, it can be concluded that irradiation at the doses tested was unable to overcome the maturation effects produced by climatization. However, the sole use of irradiation with 0.25 kGy yielded the lowest figures for fresh mass loss and disease index in the samples, thus becoming the most attractive among the treatments tested. (author)

NOAA Climate Data Record (CDR) of Total Solar Irradiance (TSI), NRLTSI Version 2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This Climate Data Record (CDR) contains total solar irradiance (TSI) as a function of time created with the Naval Research Laboratory model for spectral and total...

Effect of combination of chitosan coating and irradiation on physicochemical and functional properties of chicken egg during room-temperature storage

International Nuclear Information System (INIS)

Liu Xianxe; Jang, Aera; Kim, Dong Hun; Lee, Bong Duk; Lee, Mooha; Jo, Cheorun

2009-01-01

The effect of combination of chitosan coating and irradiation on quality and storage stability of shell egg was investigated. Salmonella typhimurium inoculated on eggshell was not detected by irradiation of 2.0 kGy at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. One-day-old fresh chicken egg was chitosan coated and irradiated at 0, 0.5, 1.0, 1.5 and 2.0 kGy by gamma ray. The egg samples were stored at room temperature for 14 days and the effects of the combination treatment on internal physicochemical and functional properties were investigated. The Haugh unit of egg was decreased by irradiation even at 0.5 kGy. Irradiation increased the lipid oxidation in egg yolk at 2 kGy but the egg with chitosan coating reduced the level of lipid oxidation. Irradiation increased the foaming ability of egg white and decreased viscosity of egg yolk and white. Results suggested that combination of irradiation and chitosan coating can improve safety of shell egg but irradiation treatment may reduce the egg quality for direct consumption. However, an improved functional property for further processing and efficient separation of egg white and yolk can be expected for egg processing industry using irradiation.

Towards Building Reliable, High-Accuracy Solar Irradiance Database For Arid Climates

Science.gov (United States)

Munawwar, S.; Ghedira, H.

2012-12-01

Middle East's growing interest in renewable energy has led to increased activity in solar technology development with the recent commissioning of several utility-scale solar power projects and many other commercial installations across the Arabian Peninsula. The region, lying in a virtually rainless sunny belt with a typical daily average solar radiation exceeding 6 kWh/m2, is also one of the most promising candidates for solar energy deployment. However, it is not the availability of resource, but its characterization and reasonably accurate assessment that determines the application potential. Solar irradiance, magnitude and variability inclusive, is the key input in assessing the economic feasibility of a solar system. The accuracy of such data is of critical importance for realistic on-site performance estimates. This contribution aims to identify the key stages in developing a robust solar database for desert climate by focusing on the challenges that an arid environment presents to parameterization of solar irradiance attenuating factors. Adjustments are proposed based on the currently available resource assessment tools to produce high quality data for assessing bankability. Establishing and maintaining ground solar irradiance measurements is an expensive affair and fairly limited in time (recently operational) and space (fewer sites) in the Gulf region. Developers within solar technology industry, therefore, rely on solar radiation models and satellite-derived data for prompt resource assessment needs. It is imperative that such estimation tools are as accurate as possible. While purely empirical models have been widely researched and validated in the Arabian Peninsula's solar modeling history, they are known to be intrinsically site-specific. A primal step to modeling is an in-depth understanding of the region's climate, identifying the key players attenuating radiation and their appropriate characterization to determine solar irradiance. Physical approach

The Patient Safety Attitudes among the Operating Room Personnel

Directory of Open Access Journals (Sweden)

Cherdsak Iramaneerat

2016-07-01

Full Text Available Background: The first step in cultivating the culture of safety in the operating room is the assessment of safety culture among operating room personnel. Objective: To assess the patient safety culture of operating room personnel at the Department of Surgery, Faculty of Medicine Siriraj Hospital, and compare attitudes among different groups of personnel, and compare them with the international standards. Methods: We conducted a cross-sectional survey of safety attitudes among 396 operating room personnel, using a short form of the Safety Attitudes Questionnaire (SAQ. The SAQ employed 30 items to assess safety culture in six dimensions: teamwork climate, safety climate, stress recognition, perception of hospital management, working conditions, and job satisfaction. The subscore of each dimension was calculated and converted to a scale score with a full score of 100, where higher scores indicated better safety attitudes. Results: The response rate was 66.4%. The overall safety culture score of the operating room personnel was 65.02, higher than an international average (61.80. Operating room personnel at Siriraj Hospital had safety attitudes in teamwork climate, safety climate, and stress recognition lower than the international average, but had safety attitudes in the perception of hospital management, working conditions, and job satisfaction higher than the international average. Conclusion: The safety culture attitudes of operating room personnel at the Department of Surgery, Siriraj Hospital were comparable to international standards. The safety dimensions that Siriraj Hospital operating room should try to improve were teamwork climate, safety climate, and stress recognition.

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.

Thermoluminescence of pure LiF and Lif (TLD-100) irradiated at room temperature

International Nuclear Information System (INIS)

Sagastibelza Chivite, F.

1980-01-01

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

The relationship of the emotional climate of work and threat to patient outcome in a high-volume thoracic surgery operating room team.

Science.gov (United States)

Nurok, Michael; Evans, Linda A; Lipsitz, Stuart; Satwicz, Paul; Kelly, Andrea; Frankel, Allan

2011-03-01

It is widely believed that the emotional climate of surgical team's work may affect patient outcome. To analyse the relationship between the emotional climate of work and indices of threat to patient outcome. Interventional study. Operating rooms in a high-volume thoracic surgery centre from September 2007 to June 2008. Thoracic surgery operating room teams. Two 90 min team-skills training sessions focused on findings from a standardised safety-culture survey administered to all participants and highlighting positive and problematic aspects of team skills, communication and leadership. Relationship of functional or less functional emotional climates of work to indices of threat to patient outcome. A less functional emotional climate corresponded to more threat to outcome in the sterile surgical environment in the pre-intervention period (pwork in the sterile surgical environment appeared to be related to threat to patient outcome prior to, but not after, a team-training intervention. Further study of the relationship between the emotional climate of work and threat to patient outcome using reproducible methods is required.

Microstructural evolution and hardening of GH3535 alloy under energetic Xe ion irradiation at room temperature and 650 °C

Science.gov (United States)

Huang, Hefei; Gao, Jie; Radiguet, Bertrand; Liu, Renduo; Li, Jianjian; Lei, Guanhong; Huang, Qing; Liu, Min; Xie, Ruobing

2018-02-01

The GH3535 alloy was irradiated with 7 MeV Xe26+ ions to a dose of 10 dpa at room temperature (RT) and 650 °C, and subsequently examined using Transmission Electron Microscopy (TEM) and nanoindentation. High numbers of nano-sized black dots, identified as dislocation loops were observed in both irradiated samples. The dislocation loops detected at the high temperature irradiated sample (size/number density: 9.5 nm/1.9 × 1021 m-3) were found to be larger in size but less in amount as compared to that of the case of RT irradiation (6.9 nm/18.7 × 1021 m-3). In addition, the large-sized Mo-Cr rich precipitates (16.4 nm/3.7 × 1021 m-3) were observed in the sample irradiated at 650 °C. Moreover, the Xe bubbles, with smaller size (2.9 nm) but higher number density (77.8 × 1021 m-3) among the irradiated induced defects, were also detected in the case of high temperature irradiated sample via the diffusion and aggregation of Xe atoms. Nanoindentaion measurements showed a hardening phenomenon for the irradiated sample, and the hardness increment is higher in the case of high temperature irradiated sample. Dispersed barrier-hardening (DBH) model was applied to predict the hardening produced from the irradiation induced defects. The yield strength increment calculated based on TEM observations and the nanohardness increment measured using nanoindentation are in excellent agreement.

Solar Irradiance Variability and Its Impacts on the Earth Climate System

Science.gov (United States)

Harder, J. W.; Woods, T. N.

The Sun plays a vital role in the evolution of the climates of terrestrial planets. Observations of the solar spectrum are now routinely made that span the wavelength range from the X-ray portion of the spectrum (5 nm) into the infrared to about 2400 nm. Over this very broad wavelength range, accounting for about 97% of the total solar irradiance, the intensity varies by more than 6 orders of magnitude, requiring a suite of very different and innovative instruments to determine both the spectral irradiance and its variability. The origins of solar variability are strongly linked to surface magnetic field changes, and analysis of solar images and magnetograms show that the intensity of emitted radiation from solar surface features in active regions has a very strong wavelength and magnetic field strength dependence. These magnetic fields produce observable solar surface features such as sunspots, faculae, and network structures that contribute in different ways to the radiated output. Semi-empirical models of solar spectral irradiance are able to capture much of the Sun's output, but this topic remains an active area of research. Studies of solar structures in both high spectral and spatial resolution are refining this understanding. Advances in Earth observation systems and high-quality three-dimensional chemical climate models provide a sound methodology to study the mechanisms of the interaction between Earth's atmosphere and the incoming solar radiation. Energetic photons have a profound effect on the chemistry and dynamics of the thermosphere and ionosphere, and these processes are now well represented in upper atmospheric models. In the middle and lower atmosphere the effects of solar variability enter the climate system through two nonexclusive pathways referred to as the top-down and bottom-up mechanisms. The top-down mechanism proceeds through the alteration of the photochemical rates that establish the middle atmospheric temperature structure and

Effects of gamma irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB)

Energy Technology Data Exchange (ETDEWEB)

Martineli, Maristella; Coneglian, Regina C.C.; Vasconcellos, Marco A.S.; Silva, Eduardo; Rocha, Janielio G.; Melo, Maruzanete P. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ. Inst. de Agronomia (Brazil)], e-mail: maristellamartineli@yahoo.com.br; Vital, Helio C. [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (Brazil). Secao de Defesa Nuclear], e-mail: vital@ctex.eb.br

2009-07-01

Banana is a highly perishable climacteric fruit. In order to ensure fast and homogeneous ripening that will make its processing and commercialization easier, it is usually treated by climatization. On the other hand, irradiation is an interesting physical process capable of delaying ripening and extending the shelf life of fruits. This work investigated the competing effects of irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB). All fruits were harvested in the preclimacteric stage, rinsed and stored at 27 deg C after being submitted to five different treatments. After hygienization, four out of five samples were exposed to gamma-ray at doses of 0.25 and 0.50 kGy. The unirradiated fruits were left for control and half of the irradiated samples were then climatized by exposure to CaC{sub 2}. Measurements of fresh mass loss, total soluble solids, peel coloration and disease index were performed on five different dates for up to nine days in order to monitor quality and the degree of ripening. It was found that high temperatures prevailing during climatization and storage accelerated maturation in all fruits in spite of the use of irradiation, with the control becoming ripe in 3 days only. In addition, based on the consistent results from the experiments performed, it can be concluded that irradiation at the doses tested was unable to overcome the maturation effects produced by climatization. However, the sole use of irradiation with 0.25 kGy yielded the lowest figures for fresh mass loss and disease index in the samples, thus becoming the most attractive among the treatments tested. (author)

Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT

International Nuclear Information System (INIS)

Evans, J.F.; Blue, T.E.

1996-01-01

Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions open-quotes How much?close quotes and open-quotes What kind?close quotes of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room, patient open-quotes scatterer,close quotes and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h -1 was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel. 20 refs., 8 figs., 2 tabs

Irradiation of onions on a large scale

International Nuclear Information System (INIS)

Kawashima, Koji; Hayashi, Toru; Uozumi, J.; Sugimoto, Toshio; Aoki, Shohei

1984-01-01

A large number of onions of var. Kitamiki and Ohotsuku were irradiated in September followed by storage at 0 deg C or 5 deg C. The onions were shifted from cold-storage facilities to room temperature in mid-March or in mid-April in the following year. Their sprouting, rooting, spoilage characteristics and sugar content were observed during storage at room temperature. Most of the unirradiated onions sprouted either outside or inside bulbs during storage at room temperature, and almost all of the irradiated ones showed small buds with browning inside the bulb in mid-April irrespective of the storage temperature. Rooting and/or expansion of bottom were observed in the unirradiated samples. Although the irradiated materials did not have root, they showed expansion of bottom to some extent. Both the irradiated and unirradiated onions spoiled slightly unless they sprouted, and sprouted onions got easily spoiled. There was no difference in the glucose content between the unirradiated and irradiated onions, but the irradiated ones yielded higher sucrose content when stored at room temperature. Irradiation treatment did not have an obvious effect on the quality of freeze-dried onion slices. (author)

Contribution to the characterization of room temperature ionic liquids under ionizing irradiation

International Nuclear Information System (INIS)

Le Rouzo, G.; Lamouroux, Ch.; Moutiers, G.

2010-01-01

Room-Temperature Ionic Liquids are potentially interesting for nuclear fuel treatment. Within this framework, ionic liquids stability towards ionizing radiations (α, β or γ) is determining their potential application. The aim of this work is to assess a better understanding of ionic liquids behaviour under radiolysis. Ionic liquids chosen in these studies are constituted with BuMeIm + (or Bu 3 MeN + ) cation associated with various anions: Tf 2 N - , TfO - , PF 6 - and BF 4 - . Moreover, development of suitable chemical analysis tools crucial for characterization of these compounds has been realized. Ionic liquids stability has been mainly studied under γ irradiation, but also under electron beam or heavy particles irradiations. Ionic liquids degradation under radiolysis has been determined with two complementary approaches. The first one aims at understanding radio-induced degradation mechanisms with radical species analysis by Electron Paramagnetic Resonance spectroscopy (EPR). The second one aims at characterizing stable radiolysis products formed in liquid and gaseous phases. Studies were conducted with several analytical techniques: Electro Spray Ionisation Mass Spectrometry (ESI-MS), High Pressure Liquid Chromatography (HPLC, HPLC/UV-VIS, HPLC/ESI-MS), Gas Analysis Mass Spectrometry (Gas MS) and Gas Chromatography hyphenated with Mass Spectrometry (GC/MS). Firstly, the ionic liquid [Bu 3 MeIm][Tf 2 N] has been studied under γ irradiation. Radiolytic stability has been quantitatively assessed for high doses of radiations and a proposal of degradation scheme has been proposed on the basis of radio-induced radicals and radiolysis products analysis. Those data have been compared to those obtained for the γ radiolysis of the ionic liquid [Bu 3 MeN][Tf 2 N], enabling to assess cation influence on ionic liquids radiolysis. Secondly, degradation under γ irradiation of ionic liquids [BuMeIm][X] (X - Tf 2 N - , TfO - , PF 6 - , BF 4 - ) has been quantitatively

Influence of γ-irradiation on the transport kinetics of hydrogen in pre-transition oxidized Zircaloy-4 at room temperature

Energy Technology Data Exchange (ETDEWEB)

Martin, Frantz A., E-mail: frantz.martin@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Aqueuse, F-91191 Gif-sur-Yvette (France); Dauvois, Vincent, E-mail: vincent.dauvois@cea.fr [CEA, DEN, DPC, SECR, Laboratoire de Radiolyse et de la Matière Organique, F-91191 Gif-sur-Yvette (France); Esnouf, Stéphane, E-mail: stephane.esnouf@cea.fr [CEA, DEN, DPC, SECR, Laboratoire de Radiolyse et de la Matière Organique, F-91191 Gif-sur-Yvette (France); CEA, DSM, IRAMIS, LIDYL, PCR, F-91191 Gif-sur-Yvette (France); Fourdrin, Chloé, E-mail: chloe.fourdrin@culture.gouv.fr [CEA, DEN, DPC, SECR, Laboratoire de Radiolyse et de la Matière Organique, F-91191 Gif-sur-Yvette (France); Jomard, François, E-mail: francois.jomard@uvsq.fr [CNRS/UVSQ, UMR 8635, GEMAC, 45 avenue des Etats Unis – Bâtiment Fermat, F-78035 Versailles (France); Chêne, Jacques, E-mail: chene_jacques@orange.fr [CNRS/CEA, UMR 8587, LECA – CEA, Saclay, F-91191 Gif-sur-Yvette (France)

2015-10-15

In a context of nuclear fuel reprocessing, the free-of-fuel hulls and ends of cladding tubes are compacted. The possibility of hydrogen degasing or absorption from/into these tubes has been studied with and without gamma irradiation at 293 K by means of deuterium as isotopic tracer for hydrogen. Under irradiation, as without, the hydrides present in the Zircaloy-4 hulls seem stable. The oxide layer present at the surface of the hulls allows a slow diffusion of deuterium, and the irradiation appeared to have no specific effect on the diffusion process: in both cases, hydrogen diffusion coefficients of the order of 5·10{sup −18} cm{sup 2} s{sup −1} have been found. The subsurface activity of deuterium is increased by one order of magnitude at least under irradiation, probably due to an activation of the dissociation/absorption kinetic steps. - Highlights: • Hydrogen diffusion coefficients at RT in zirconia grain boundaries were determined. • γ irradiation increases the hydrogen subsurface activity when exposed to H{sub 2} gas. • The dense thin zirconia film is not altered much by HNO{sub 3} exposure at 90 °C for 24 h. • Hydrogen desorption from Zr hydrides was studied at room temperature under γ rays.

Clean industrial room for drift tube assembling

International Nuclear Information System (INIS)

Glonti, G.L.; Gongadze, A.L.; Evtukhovich, P.G.

2001-01-01

Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volume (∼ 190 m 3 ), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2%). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer. (author)

Clean Industrial Room for Drift Tube Assembling

CERN Document Server

Glonti, GL; Evtoukhovitch, P G; Kroa, G; Manz, A; Potrap, I N; Rihter, P; Stoletov, G D; Tskhadadze, E G; Chepurnov, V F; Chirkov, A V; Shelkov, G A

2001-01-01

Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has been confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volum (\\sim 190 m^3), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2 %). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer.

Formation of rutile fasciculate zone induced by sunlight irradiation at room temperature and its hemocompatibility

International Nuclear Information System (INIS)

Zhang, Xuan-Hui; Zheng, Xiang; Cheng, Yuan; Li, Guo-Hua; Chen, Xiao-Ping; Zheng, Jian-Hui

2013-01-01

The fasciculate zone of phase pure rutile was fabricated under sunlight irradiation at room temperature, using titanium tetrachloride as a sole precursor. The crystal phase, morphology and microstructure, and optical absorption behavior of the samples were characterized by X-ray Diffraction, High-Resolution Transmission Electron Microscope (HRTEM) and UV–vis Diffuse Reflectance Spectra (DRS), respectively. XRD results show that the crystal phase of the sample is composed of rutile only, and a lattice distortion displays in the crystallite of the sample. HRTEM results show that the morphology of rutile particle is fasciculate zone constituted of nanoparticles with a diameter of 4–7 nm, and these particles grow one by one and step by step. The pattern of the selected area electron diffraction of the sample is Kikuchi type, which can be attributed to the predominant orientation growth of rutile nanoparticles along [001] induced by sunlight irradiation. DRS results show that the absorption threshold of the sample is 415 nm, corresponding to the band gap energy of 2.99 eV, which is lower than the band gap energy of rutile, 3.03 eV. Blood compatibility measurement shows that the sample has no remarkable effect on hemolytic and coagulation activity. The percent hemolysis of red blood cells is less than 5% even treated with a big dosage of the fasciculate rutile and under UV irradiation, and there are no obvious changes of plasma recalcification time after the rutile treatment. Thus, the novel structure of rutile fasciculate has low potential toxicity for blood and is hemocompatibility safe. Highlights: • A novel approach to fabricate the fasciculate zone of phase pure rutile • The fasciculate grows from a particle to nanorod and to fasciculate, step by step. • A preferred orientation growth induced by sunlight irradiation in the fasciculate • The rutile fasciculate is low toxicity for blood and is hemocompatibility safe

Update of the Picker C9 irradiator control system of the gamma II room of the secondary laboratory of dosimetric calibration

International Nuclear Information System (INIS)

Simon S, L. E.

2016-01-01

The Picker C9 irradiator is responsible for the calibration of different radiological equipment and the control system that maintains it in operation is designed in the graphical programming software LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench), being its major advantages: the different types of communication, easy interconnection with other software and the recognition of different hardware devices, among others. Operation of the irradiator control system is performed with the NI-Usb-6008 (DAQ) data acquisition module of the National Instruments Company. The purpose of this work is to update the routines that make the Picker C9 control system of the gamma II room of the secondary laboratory of dosimetric calibration, using the graphic programming software LabVIEW, as well as to configure the new acquisition hardware of data that is implemented to control the Picker C9 irradiator system and ensure its operation. (Author)

Irradiation-induced amorphization process in graphite

Energy Technology Data Exchange (ETDEWEB)

Abe, Hiroaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1996-04-01

Effects of the element process of irradiation damage on irradiation-induced amorphization processes of graphite was studied. High orientation thermal decomposed graphite was cut about 100 nm width and used as samples. The irradiation experiments are carried out under the conditions of electronic energy of 100-400 KeV, ion energy of 200-600 KeV, ionic species Xe, Ar, Ne, C and He and the irradiation temperature at from room temperature to 900 K. The critical dose ({phi}a) increases exponentially with increasing irradiation temperature. The displacement threshold energy of graphite on c-axis direction was 27 eV and {phi}a{sup e} = 0.5 dpa. dpa is the average number of displacement to atom. The critical dose of ion irradiation ({phi}a{sup i}) was 0.2 dpa at room temperature, and amorphous graphite was produced by less than half of dose of electronic irradiation. Amorphization of graphite depending upon temperature is discussed. (S.Y.)

Evaluation for activities of component of Cyclotron-Based Epithermal Neutron Source (C-BENS) and the surface of concrete wall in irradiation room

Energy Technology Data Exchange (ETDEWEB)

Imoto, M., E-mail: masayuki.imoto@gmail.com [Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Tanaka, H. [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan); Fujita, K.; Mitsumoto, T. [Sumitomo Heavy Industries, Ltd., Tokyo 141-6025 (Japan); Ono, K.; Maruhashi, A.; Sakurai, Y. [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan)

2011-12-15

The workers employed in BNCT must enter the irradiation room just after an irradiation under the condition of remaining activities. To reduce the radiation exposure for the workers, it is important to identify the origins of the activities. In this research, the activities induced on the concrete wall surface were evaluated using MCNP-5 and the measurement results of thermal neutron distribution. Furthermore, the radioisotopes produced in the moderator were identified with a High Purity Germanium detector. It was found that the activities of the wall were mainly caused by {sup 46}Sc, {sup 60}Co and {sup 152}Eu, and that {sup 24}Na and {sup 56}Mn were mainly produced in the moderator.

Damage nucleation in Si during ion irradiation

International Nuclear Information System (INIS)

Holland, O.W.; Fathy, D.; Narayan, J.

1984-01-01

Damage nucleation in single crystals of silicon during ion irradiation is investigated. Experimental results and mechanisms for damage nucleation during both room and liquid nitrogen temperature irradiation with different mass ions are discussed. It is shown that the accumulation of damage during room temperature irradiation depends on the rate of implantation. These dose rate effects are found to decrease in magnitude as the mass of the ions is increased. The significance of dose rate effects and their mass dependence on nucleation mechanisms is discussed

Effect of helium irradiation on fracture modes

International Nuclear Information System (INIS)

Hanamura, T.; Jesser, W.A.

1982-01-01

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

Market Trials of Irradiated Spices

International Nuclear Information System (INIS)

Charoen, Saovapong; Eemsiri, Jaruratana; Sajjabut, Surasak

2009-07-01

Full text: The objectives of the experiment were to disseminate irradiated retail foods to the domestic publics and to test consumer acceptance on irradiated ground chilli and ground pepper. Market trials of irradiated ground chilli and ground pepper were carried out at 2 local markets and 4 in Bangkok and Nontaburi in 2005-2007. Before the start of the experiment, processing room, gamma irradiation room and labels of the products were approved by Food and Drug Administration, Thailand. 50 grams of irradiated products were packaged in plastic bags for the market trials. 688 and 738 bags of ground chilli and ground pepper were sold, respectively. Questionnaires distributed with the products were commented by 59 consumers and statistically analyzed by experimental data pass program. 88.1 and 91.4 percents of the consumers were satisfied with the quality and the price, respectively. 79.7% of the consumers chose to buy irradiated ground chilli and ground pepper because they believed that the quality of irradiated products were better than that of non-irradiated ones. 91.5% of the consumers would certainly buy irradiated chilli and pepper again. Through these market trials, it was found that all of the products were sold out and the majority of the consumers who returned the questionnaires was satisfied with the irradiated ground chilli and ground pepper and also had good attitude toward irradiated foods

The IMO-1 mobile irradiation unit

International Nuclear Information System (INIS)

Cancio, Ruben; Gomez, Aristobulo; Mugliaroli, Hugo.

1976-07-01

The IMO-I is made up by a gamma irradiation bucket and a fixed source, mounted on a trailer specially designed. This equipment has been completed with a radiocomunication device. The irradiator unit consist of two fixed and one movable body. The irradiation bucket has a volume of 30 x 40 x 30 cm and is moved through an hydraulic system with allows its vertical movement between the upper or charging position and the bottom or irradiation position. The telecontrol device has been installed in the room contiguous to the irradiator. The conventional industrial sources of Co 60 , are vertically located in stainless steel source holders at the botton fixed body and they can be changed according with the desired geometry. The trailer has been built over a plain chassis assembled structure with a double axle at the rear. It consists of two rooms, one for the irradiator machine and the other one for the telecontrol device and the radiocomunication facility. (author) [es

Subjective rating and objective evaluation of the acoustic and indoor climate conditions in video conferencing rooms

DEFF Research Database (Denmark)

Hauervig-Jørgensen, Charlotte; Jeong, Cheol-Ho; Toftum, Jørn

2017-01-01

Today, face-to-face meetings are frequently replaced by video conferences in order to reduce costs and carbon footprint related to travels and to increase the company efficiency. Yet, complaints about the difficulty of understanding the speech of the participants in both rooms of the video...... conference occur. The aim of this study is to find out the main causes of difficulties in speech communication. Correlation studies between subjective perceptions were conducted through questionnaires and objective acoustic and indoor climate parameters related to video conferencing. Based on four single...

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

International Nuclear Information System (INIS)

Mariani, D. F.

1977-01-01

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

Advancing Solar Irradiance Measurement for Climate-Related Studies: Accurate Constraint on Direct Aerosol Radiative Effect (DARE)

Science.gov (United States)

Tsay, Si-Chee; Ji, Q. Jack

2011-01-01

Earth's climate is driven primarily by solar radiation. As summarized in various IPCC reports, the global average of radiative forcing for different agents and mechanisms, such as aerosols or CO2 doubling, is in the range of a few W/sq m. However, when solar irradiance is measured by broadband radiometers, such as the fleet of Eppley Precision Solar Pyranometers (PSP) and equivalent instrumentation employed worldwide, the measurement uncertainty is larger than 2% (e.g., WMO specification of pyranometer, 2008). Thus, out of the approx. 184 W/sq m (approx.263 W/sq m if cloud-free) surface solar insolation (Trenberth et al. 2009), the measurement uncertainty is greater than +/-3.6 W/sq m, overwhelming the climate change signals. To discern these signals, less than a 1 % measurement uncertainty is required and is currently achievable only by means of a newly developed methodology employing a modified PSP-like pyranometer and an updated calibration equation to account for its thermal effects (li and Tsay, 2010). In this talk, we will show that some auxiliary measurements, such as those from a collocated pyrgeometer or air temperature sensors, can help correct historical datasets. Additionally, we will also demonstrate that a pyrheliometer is not free of the thermal effect; therefore, comparing to a high cost yet still not thermal-effect-free "direct + diffuse" approach in measuring surface solar irradiance, our new method is more economical, and more likely to be suitable for correcting a wide variety of historical datasets. Modeling simulations will be presented that a corrected solar irradiance measurement has a significant impact on aerosol forcing, and thus plays an important role in climate studies.

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

International Nuclear Information System (INIS)

Keshek, A. B.

2010-01-01

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

A New Revision of the Solar Irradiance Climate Data Record Incorporates Recent Research into Proxies of Sunspot Darkening and the Sunspot Number Record

Science.gov (United States)

Coddington, O.; Lean, J.; Pilewskie, P.; Baranyi, T.; Snow, M. A.; Kopp, G.; Richard, E. C.; Lindholm, C.

2017-12-01

An operational climate data record (CDR) of total and spectral solar irradiance became available in November 2015 as part of the National Oceanographic and Atmospheric Administration's National Centers for Environmental Information Climate Data Record Program. The data record, which is updated quarterly, is available from 1610 to the present as yearly-average values and from 1882 to the present as monthly- and daily-averages, with associated time and wavelength-dependent uncertainties. It was developed jointly by the University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics and the Naval Research Laboratory, and, together with the source code and supporting documentation, is available at https://www.ncdc.noaa.gov/cdr/. In the Solar Irradiance CDR, total solar irradiance (TSI) and solar spectral irradiance (SSI) are estimated from models that determine the changes from quiet Sun conditions arising from bright faculae and dark sunspots on the solar disk. The models are constructed using linear regression of proxies of solar sunspot and facular features with the approximately decade-long irradiance observations from the SOlar Radiation and Climate Experiment. A new revision of this data record was recently released in an ongoing effort to reduce solar irradiance uncertainties in two ways. First, the sunspot darkening proxy was revised using a new cross calibration of the current sunspot region observations made by the Solar Observing Optical Network with the historical records of the Royal Greenwich Observatory. This implementation affects modeled irradiances from 1882 - 1978. Second, the impact of a revised record of sunspot number by the Sunspot Index and Long-term Solar Observations center on modeled irradiances was assessed. This implementation provides two different reconstructions of historical, yearly-averaged irradiances from 1610-1881. Additionally, we show new, preliminary results that demonstrate improvements in modeled TSI by using

Optical absorption and thermoluminescence in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature

International Nuclear Information System (INIS)

Delgado, L.

1984-01-01

Optical absorption and thermoluminescence (TL) studies in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature are presented. In pure Mg O the thermal annihilation of Fe3+ by recombination with thermally released electrons at ∼ 90 and 175 degree centigree and the V center annealing by hole release up to 100 degree centigree cause the observed glow peaks at these temperatures. The TL excitation spectrum shows two maxima at 245 nm (electron center) and 288 nm (Fe3+). In Mg O:Ni X irradiation induces Fe 2 + →- Fe 3 + and Ni 2 + → Ni 3 + oxidations. Two TL emission bands centered at 110 degree centigree (red) and 80 o C (green) are assigned to electron release and their recombination at Fe 3 + and Ni 3 + respectively. In Mg O:Li two TL emission bands, one blue (430 nm) and the other red (730 nm) with excitation maxima at 245 nm (electron center) and 200 nm (hole center) respectively are observed. No V-center formation was detected in both Ni and Li doped samples. (Author) 42 refs

ESR and spin-trapping study of room-temperature radicals in γ-irradiated polycrystalline pyrimidine nucleotides

International Nuclear Information System (INIS)

Zhang, Z.; Kuwabara, M.; Yoshii, G.

1983-01-01

Free radicals produced in γ-irradiated polycrystalline 5'-dCMP (free acid and 2Na), 3'-CMP (free acid and Li), and 5'-UMP (2Na) were studied by ESR and spin-trapping. The results were compared with those of previous single-crystal studies. Furthermore, attempts to identify free radicals in γ-irradiated 5'-dUMP (2Na), 5'-CMP (free acid and 2Na), and 3'-UMP (Na), which have not been the subject of single-crystal studies to date, were made. After γ-irradiation at room temperature to a dose of 100 kGy, the polycrystalline samples were dissolved in aqueous solutions of t-nitrosobutane in the presence or absence of oxygen. The presence or absence of oxygen was helpful in analyzing the presence of more than one radical species. Thus two types of radicals could be established for all samples. Radical -C 5 H-C 6 H 2 -, formed by H addition to the double bond of the base, was observed in the presence of oxygen, and radical -C/sub 5'/H 2 , formed by the transformation of the radical due to loss of an H atom at the C/sub 5'/ position of the sugar moiety, was observed in the absence of oxygen. In some cases, radicals located at the C/sub 1'/, C/sub 4'/, and C/sub 5'/ of the sugar moiety were tentatively identified. For the ESR spectrum associated with radical at C/sub 1'/ the possibility of another explanation was also discussed in relation to the spectrum due to radical at C 5 of the base. Radical -C 5 H 2 -C 6 H-, formed by H addition to the double bond of the base, was not identified

Effects of irradiation at low temperature on V-4Cr-4Ti

International Nuclear Information System (INIS)

Alexander, D.J.; Snead, L.L.; Zinkle, S.J.

1996-01-01

Irradiation at low temperatures (100 to 275 degrees C) to 0.5 dpa causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile flow properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform ductility. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275 degrees C. This embrittlement is not due to pickup of O or other interstitial solutes during the irradiation

Effects of irradiation at low temperature on V-4Cr-4Ti

Energy Technology Data Exchange (ETDEWEB)

Alexander, D.J.; Snead, L.L.; Zinkle, S.J. [Oak Ridge National Lab., TN (United States)] [and others

1996-10-01

Irradiation at low temperatures (100 to 275{degrees}C) to 0.5 dpa causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile flow properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform ductility. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275{degrees}C. This embrittlement is not due to pickup of O or other interstitial solutes during the irradiation.

Nanoporous gold synthesized by plasma-assisted inert gas condensation: room temperature sintering, nanoscale mechanical properties and stability against high energy electron irradiation

Science.gov (United States)

Weyrauch, S.; Wagner, C.; Suckfuell, C.; Lotnyk, A.; Knolle, W.; Gerlach, J. W.; Mayr, S. G.

2018-02-01

With a plasma assisted gas condensation system it is possible to achieve high-purity nanoporous Au (np-Au) structures with minimal contaminations and impurities. The structures consist of single Au-nanoparticles, which partially sintered together due to their high surface to volume ratio. Through electron microscopy investigations a porosity  >50% with ligament sizes between 20-30 nm was revealed. The elastic modulus of the np-Au was determined via peak force quantitative nanomechanical mapping and resulted in values of 7.5  ±  1.5 GPa. The presented structures partially sintered at room temperature, but proved to be stable to electron irradiation with energies of 7 MeV up to doses of 100 MGy. The electron irradiation stability opens the venue for electron assisted functionalization with biomolecules.

Reconstruction of Co-60 Irradiation Facility No.1

International Nuclear Information System (INIS)

Nakamura, Yoshiteru; Takada, Isao; Kaneko, Hirohisa; Hirao, Toshio; Haneda, Noriyuki; Mitomo, Shouichi; Tachibana, Hiroyuki; Yoshida, Kenzou

1989-01-01

Cobalt Irradiation Facility No.1 was constructed in 1964 as the first large scale Co-60 irradiation facility equipped a deep water pool for source storage of Co-60 sources. Recently, the reconstruction of the facility was decided because the aging of various parts of the facility became remarkable and new research programs required upgradings of the facility. Important points of upgradings are as follows: A shielding capacity of the source storage and pool is increased to 55.5 PBq from 18.5 PBq. The opening in a floor of the irradiation room which is used for the source lifting in the room, is enlarged in order to utilize a large and high intensity source. Radiation resistance of the irradiation apparatus and installed equipments in the radiation room is increased for a high dose rate irradiation. Basic structure and shape of the facility building such as shielding, pool and building roof is not changed but electrical, mechanical equipments and systems are completely renewed. To increase a reliability, the irradiation apparatus and systems are also replaced with an improved and up-to-date one designed based on operation experiences of Co-60 facilities at TRCRE through many years. In addition, auxiliary equipments such as radiation monitors, manipulators, water treatment system and so on are replaced. This report presents the reconstruction of Co-60 Irradiation Facility No.1 stressing on the replacement and modification of the irradiation apparatus. (author)

Effect of gamma irradiation on the sensitivities of escherichia coli at deep frozen conditions

International Nuclear Information System (INIS)

Takigami, Machiko; Ito, Hitoshi

1996-01-01

Phosphate buffer suspensions of three strains of Escherichia coli were irradiated with gamma-rays at room temperature and deep frozen conditions. They were inoculated on MacConkey agar plates to see the comparative sensitivities to the irradiation. Compared to the irradiation at room temperature, the sensitivities of the strains decreased by irradiation at deep frozen conditions. Addition of glycerol to the E. coli suspensions decreased the sensitivities of E. coli to gamma-rays not only at room temperature but also at deep frozen conditions. These phenomena were elucidated by the decrease of production and mobility of OH radicals at deep frozen conditions. (author)

Investigations on 40 MeV Li3+ ions irradiated GaN epilayers

International Nuclear Information System (INIS)

Suresh Kumar, V.; Kumar, J.; Kanjilal, D.; Asokan, K.; Mohanty, T.; Tripathi, A.; Rossi, Francisca; Zappettini, A.; Lazzarani, L.; Ferrari, C.

2008-01-01

The Metal Organic Chemical Vapour Deposition (MOCVD) grown n-type Gallium nitride (GaN) layers on sapphire (0 0 0 1) substrates have been irradiated at low and room temperatures with 40 MeV Li 3+ ions at the fluence of 1 x 10 13 ions cm -2 . Irradiated samples were characterised by using X-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and atomic force microscopy (AFM). XRD results show that the formation of Ga 2 O 3 has been observed upon irradiation. This is due to interface mixing of GaN/Al 2 O 3 , at both temperatures. Also the GaN (0 0 0 2) peak splits into two at low temperature irradiation. PL measurements show a yellow emission band shift towards blue band side upon irradiation at 77 K. Raman studies indicate that the lattice disorder is high at room temperature irradiation compared to low temperature irradiation. AFM images indicate the increasing surface roughness after ion irradiation at room temperature when compared to pristine GaN and low temperature irradiated GaN. These observations are discussed in detail with the use of complementary techniques

Clear-Sky Longwave Irradiance at the Earth's Surface--Evaluation of Climate Models.

Science.gov (United States)

Garratt, J. R.

2001-04-01

An evaluation of the clear-sky longwave irradiance at the earth's surface (LI) simulated in climate models and in satellite-based global datasets is presented. Algorithm-based estimates of LI, derived from global observations of column water vapor and surface (or screen air) temperature, serve as proxy `observations.' All datasets capture the broad zonal variation and seasonal behavior in LI, mainly because the behavior in column water vapor and temperature is reproduced well. Over oceans, the dependence of annual and monthly mean irradiance upon sea surface temperature (SST) closely resembles the observed behavior of column water with SST. In particular, the observed hemispheric difference in the summer minus winter column water dependence on SST is found in all models, though with varying seasonal amplitudes. The analogous behavior in the summer minus winter LI is seen in all datasets. Over land, all models have a more highly scattered dependence of LI upon surface temperature compared with the situation over the oceans. This is related to a much weaker dependence of model column water on the screen-air temperature at both monthly and annual timescales, as observed. The ability of climate models to simulate realistic LI fields depends as much on the quality of model water vapor and temperature fields as on the quality of the longwave radiation codes. In a comparison of models with observations, root-mean-square gridpoint differences in mean monthly column water and temperature are 4-6 mm (5-8 mm) and 0.5-2 K (3-4 K), respectively, over large regions of ocean (land), consistent with the intermodel differences in LI of 5-13 W m2 (15-28 W m2).

Reassessment of shielding calculations for a room housing a Cesium-137 irradiator

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Leticia S.; Barbosa, Rugles C., E-mail: leticia.fmufg@gmail.com, E-mail: rbarbosa@cnen.gov.br [Centro Regional de Ciências Nucleares do Centro Oeste (CRCN-CO/CNEN-GO), Abadia de Goiás, GO (Brazil); Rezende, Ana C.B., E-mail: anacbrz@gmail.com [Universidade Federal de Goiás (UFG), Goiânia, GO (Brazil). Escola de Engenharia

2017-07-01

This aim of this work is to reassess the shielding calculations for a room that houses an irradiator with cesium-137 ({sup 137}Cs) source with activity of 444GBq (12Ci). Shielding or barriers have the function of reducing the intensity of the radiation emitted by a radioactive source, are constituted by materials of high atomic number and guarantee the radiological protection in areas occupied by occupationally exposed individuals or by individuals of the public. The barriers located in the direction of the direct beam of radiation are called primary barriers and are thicker. Already the barriers that attenuate the radiation scattered by the radiated surface are called secondary barriers. In the new calculations, the thickness of the primary barrier was determined by model of the point nucleus model and for the secondary barriers, the differential albedo dose model was used. The results obtained show that all secondary barriers were constructed with overestimated thicknesses and that the radiological protection of individuals from the public and occupationally exposed individuals in the areas outside these barriers is guaranteed. The primary barrier was constructed with a thickness 8% smaller than the thickness obtained in the new calculations. In addition to shielding calculations, classification and signaling of adjacent areas were performed, including necessary emergency procedures. The necessary instrumentation for monitoring these areas was also determined. (author)

Reassessment of shielding calculations for a room housing a Cesium-137 irradiator

International Nuclear Information System (INIS)

Oliveira, Leticia S.; Barbosa, Rugles C.; Rezende, Ana C.B.

2017-01-01

This aim of this work is to reassess the shielding calculations for a room that houses an irradiator with cesium-137 ( 137 Cs) source with activity of 444GBq (12Ci). Shielding or barriers have the function of reducing the intensity of the radiation emitted by a radioactive source, are constituted by materials of high atomic number and guarantee the radiological protection in areas occupied by occupationally exposed individuals or by individuals of the public. The barriers located in the direction of the direct beam of radiation are called primary barriers and are thicker. Already the barriers that attenuate the radiation scattered by the radiated surface are called secondary barriers. In the new calculations, the thickness of the primary barrier was determined by model of the point nucleus model and for the secondary barriers, the differential albedo dose model was used. The results obtained show that all secondary barriers were constructed with overestimated thicknesses and that the radiological protection of individuals from the public and occupationally exposed individuals in the areas outside these barriers is guaranteed. The primary barrier was constructed with a thickness 8% smaller than the thickness obtained in the new calculations. In addition to shielding calculations, classification and signaling of adjacent areas were performed, including necessary emergency procedures. The necessary instrumentation for monitoring these areas was also determined. (author)

Temporal derivative of Total Solar Irradiance and anomalous Indian summer monsoon: An empirical evidence for a Sun–climate connection

Digital Repository Service at National Institute of Oceanography (India)

Agnihotri, R.; Dutta, K.; Soon, W.

and Solar-Terrestrial Physics 73 (2011) 1980–1987 1985 a factor of 5–10 times larger than the top of the atmosphere forcing. Several other researchers have also carefully evaluated and highlighted the complex pathways and processes that may be involved... irradiance and the variance of ENSO variability. Hence, a meaningful study of Sun– climate relation must involve not only careful consideration of the solar forcing factors, but also the proper measures for the local and regional climatic responses...

Storage properties of irradiated potatoes and onions. Part of a coordinated programme on the Asian Regional Cooperative Project on Food Irradiation

International Nuclear Information System (INIS)

Hayashi, T.

1984-12-01

Quality changes with regard to browning of inner buds and sprouting of irradiated onions variety Kitamiki and Ohotsuku were investigated. One ton of each variety was irradiated with either 38.1 or 65.2 Gy at the Commercial Potato Irradiator in Shihoro and stored either at 0 deg. C or 5 deg. C. After 6 months of storage, they were taken out to be stored at room temperature. It was observed that green inner buds developed in most unirradiated onions which showed no external sprouting irrespective of storage temperature. Irradiated onions show no external or internal sprouting but exhibited browning of small inner buds. Unirradiated onions rooted slightly during storage at low temperature. None of the irradiated samples showed rooting. Neither of the samples spoiled significantly during storage. It was concluded that storage at room temperature accelerated sprouting and development of green inner buds of unirradiated onions and browning of small inner buds in irradiated ones. During off-seasons, only irradiated onions stored at low temperatures have qualities of commercial significance

Americium-241 use of measurement lead equivalent thickness for medical x-ray room: A review

International Nuclear Information System (INIS)

Mohd Khalid Matori; Husaini Saleh; Abd Aziz Mhd Ramli; Muhammad Jamal Md Isa; Mohd Firdaus Abd Rahman; Zainal Jamaluddin

2010-01-01

Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for X-ray room at health centres. Results of measurement of 30 irradiation rooms conducted from 2009 to mid 2010 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that 96.7 % of the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

Dose estimation of the THOR BNCT treatment room

International Nuclear Information System (INIS)

Hsu, F.Y.; Liu, H.M.; Yu, C.C.; Huang, Y.H.; Tsai, H.N.

2006-01-01

BNCT beam of Tsing Hua Open-pool Reactor (THOR) was designed and constructed since 1998. A treatment room for the newly modified THOR BNCT beam was constructed for the next clinical-stage trials in 2004. Dose distribution in a patient (or a phantom) is important as irradiated with the BNCT beam. The dose distributions for different type of radiations such as neutron and photons in the treatment room are strongly becoming the index or reference of success for a BNCT facility. An ART head phantom was placed in front of the THOR BNCT beam port and was irradiated. In each section of the head phantom, numbers of small holes are inside and separated uniformly. Dual detector: TLD-600 and TLD-700 chips were placed inside these holes within the phantom to distinct doses of neutron and photon. Besides, Dual-TLD chips were latticed placed in the horizontal plane of beam central axis, in the treatment room to estimate the spatial dose distribution of neutron and photon. Gold foils were assisted in TLD dose calibrations. Neutron and photon dose distributions in phantom and spatial dose distributions in the THOR BNCT treatment room were both estimated in this work. Testing and improvement in THOR BNCT beam were continuative during these years. Results of this work could be the reference and be helpful for the further clinical trials in nearly future. (author)

Effect of Ion Irradiation in Cadmium Niobate Pyrochlores

International Nuclear Information System (INIS)

Jiang, Weilin; Weber, William J.; Thevuthasan, Suntharampillai; Boatner, Lynn A.

2003-01-01

Irradiation experiments have been performed for cadmium niobate pyrochlore (CdNb2O) single crystals at both 150 and 300 K using 1.0 MeV Au ions over fluences ranging from 0.01 to 0.10 ions/nm. In-situ 3.0 MeV He Rutherford backscattering spectrometry along the -axial channeling direction (RBS/C) has been applied to study the damage states ranging from small defect concentrations to a fully amorphous state. Results show that the crystal can be readily amorphized under the irradiation conditions. Room-temperature recovery of the defects produced at 150 K has been observed, while the defects produced at 300 K are thermally stable at room temperature. Results also indicate that the RBS/C analysis used in this study induced negligible damage in the near-surface regime. In addition, irradiation at and below room temperature using He and C3 ions leads to surface exfoliation at the corresponding damage peaks

Ultraviolet (UV)-reflective paint with ultraviolet germicidal irradiation (UVGI) improves decontamination of nosocomial bacteria on hospital room surfaces.

Science.gov (United States)

Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

2017-06-01

An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm 2 between sites with standard paint and 0-553 mJ/cm 2 with UV-reflective paint) in 8 total trials. Aggregated MRSA concentrations on plastic bedrail surface coupons were reduced on average by 3.0 log 10 (1.8 log 10 Geometric Standard Deviation [GSD]) with standard paint and 4.3 log 10 (1.3 log 10 GSD) with UV-reflective paint (p = 0.0005) with no significant reduction differences between paints on stainless steel and chrome. Average VRE concentrations were reduced by ≥4.9 log 10 (surface types with UV-reflective paint and ≤4.1 log 10 (hospital bed from the UVGI generator, MRSA concentrations on average were reduced by 1.3 log 10 (1.7 log 10 GSD) with standard paint and 4.7 log 10 (1.3 log 10 GSD) with UV-reflective paint (p hospital room walls with UV-reflective paint enhanced UVGI disinfection of nosocomial bacteria on various surfaces compared to standard paint, particularly at a surface placement site indirectly exposed to UVC light.

In Situ Irradiation and Measurement of Triple Junction Solar Cells at Low Intensity, Low Temperature (LILT) Conditions

Science.gov (United States)

Harris, R.D.; Imaizumi, M.; Walters, R.J.; Lorentzen, J.R.; Messenger, S.R.; Tischler, J.G.; Ohshima, T.; Sato, S.; Sharps, P.R.; Fatemi, N.S.

2008-01-01

The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out in situ at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell

2 MeV, 60 kW dual-beam type electron accelerator irradiation facility

International Nuclear Information System (INIS)

Yotsumoto, Keiichi; Kanazawa, Takao; Haruyama, Yasuyuki; Agematsu, Takashi; Mizuhashi, Kiyoshi; Sunaga, Hiromi; Washino, Masamitsu; Tamura, Naoyuki

1984-02-01

The specification of new irradiation facility which has been constructed from 1978 through 1981 as the replacement of 1st Accelerator of JAERI, TRCRE are described. The accelerator is the Cockcroft-Walton type and both vertical and horizontal accelerating tubes are arranged on a single high voltage generator. Transferring of the high voltage to the horizontal accelerating tube is performed with the high voltage changing system in the pressure vessel. The output ratings of the accelerator are 2 MV of acceleration voltage and 30 mA of beam current. By providing the dual beam system, two irradiation rooms, one for vertical and the other for horizontal beam, are independently operationable. Persons can enter the horizontal irradiation room for experimental setting even when the vertical irradiation room is in operation. The specification of the buildings, the exhaust air treatment system, the irradiation conveyor and the safety observation system are also described. (author)

Detection of irradiated strawberries by identifying ESR peak of irradiated cellulose component

International Nuclear Information System (INIS)

Goto, Michiko; Tanabe, Hiroko

2002-01-01

The method of detecting low-dose irradiated strawberries by identifying ESR peak of irradiated cellulose component was studied. Ratio of peak height (S) of high magnetic field cellulose component, and noise width (N) of either irradiated or unirradiated seeds of strawberries were compared. In this study, sample was identified to be irradiated when S/N ratio of ESR spectrum of 4 min. sweep time was above 0.7. In the case of S/N ratio below 0.7, when the S/N ratio of integrated ESR spectrum, obtained from measuring 10 times with 1 min. sweep time was above 1.0, the sample was identified to be irradiated. The result suggests that S/N ratio is a good marker to detect the irradiation. The strawberries irradiated above 0.5kGy was able to be detected after 3 days storage at room temperature, after 21 days refrigeration and after 60 days freezing, respectively. (author)

500 keV Ar2+ ion irradiation induced anatase to brookite phase transformation and ferromagnetism at room temperature in TiO2 thin films

Science.gov (United States)

Bharati, B.; Mishra, N. C.; Kanjilal, D.; Rath, Chandana

2018-01-01

In our earlier report, where we have demonstrated ferromagnetic behavior at room temperature (RT) in TiO2 thin films deposited through electron beam evaporation technique followed by annealing either in Ar or O2 atmosphere [Mohanty et al., Journal of Magnetism and Magnetic Materials 355 (2014) 240-245], here we have studied the evolution of structure and magnetic properties after irradiating the TiO2 thin films with 500 keV Ar2+ ions. The pristine film while exhibits anatase phase, the films become amorphous after irradiating at fluence in the range 1 × 1014 to 1 × 1016 ions/cm2. Increasing the fluence up to 5 × 1016 ions/cm2, amorphous to crystalline phase transformation occurs and the structure becomes brookite. Although anatase to rutile phase transformation is usually reported in literatures, anatase to brookite phase transformation is an unusual feature which we have reported here for the first time. Such anatase to brookite phase transformation is accompanied with grain growth without showing any change in film thickness evidenced from Rutherford's Back Scattering (RBS) measurement. From scanning probe micrographs (SPM), roughness is found to be more in amorphous films than in the crystalline ones. Anatase to brookite phase transformation could be realized by considering the importance of intermediate amorphous phase. Because due to amorphous phase, heat deposited by energetic ions are localized as dissipation of heat is less and as a result, the localized region crystallizes in brookite phase followed by grain growth as observed in highest fluence. Further, we have demonstrated ferromagnetic behavior at RT in irradiated films similar to pristine one, irrespective of their phase and crystallinity. Origin for room temperature ferromagnetism (RTFM) is attributed to the presence of oxygen vacancies which is confirmed by carrying out XPS measurement.

Preservation of goose product by irradiation

International Nuclear Information System (INIS)

Chen Xiulan; Cao Hong; Bao Jianzhong; Zhai Jianqing; Wang Jinrong; Han Yan; Jiang Yunsheng; Dong Jie

2005-01-01

The influence of temperature, packaging material and irradiation on the shelf life of cooked goose was investigated in this paper. The results showed that irradiation (6 kGy for salted goose and 4 kGy for wind-goose) could extend the shelf life of vacuum Aluminium foil package goose for 2 months at room temperature. (authors)

Effect of swift heavy ion irradiation on structural and opto-electrical properties of bi-layer CdS-Bi2S3 thin films prepared by solution growth technique at room temperature

Science.gov (United States)

Shaikh, Shaheed U.; Siddiqui, Farha Y.; Desale, Deepali J.; Ghule, Anil V.; Singh, Fouran; Kulriya, Pawan K.; Sharma, Ramphal

2015-01-01

CdS-Bi2S3 bi-layer thin films have been deposited by chemical bath deposition method on Indium Tin Oxide glass substrate at room temperature. The as-deposited thin films were annealed at 250 °C in an air atmosphere for 1 h. An air annealed thin film was irradiated using Au9+ ions with the energy of 120 MeV at fluence 5×1012 ions/cm2 using tandem pelletron accelerator. The irradiation induced modifications were studied using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Raman spectroscopy, UV spectroscopy and I-V characteristics. XRD study reveals that the as-deposited thin films were nanocrystalline in nature. The decrease in crystallite size, increase in energy band gap and resistivity were observed after irradiation. Results are explained on the basis of energy deposited by the electronic loss after irradiation. The comparative results of as-deposited, air annealed and irradiated CdS-Bi2S3 bi-layer thin films are presented.

Onion irradiation - a case study

International Nuclear Information System (INIS)

Huebner, G.

1988-01-01

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

Exposure to aerosol and gaseous pollutants in a room ventilated with mixing air distribution

DEFF Research Database (Denmark)

Bivolarova, Mariya Petrova; Ondráček, Jakub; Ždímal, Vladimír

2016-01-01

The present study investigates the aerosol and gas dispersal in a mechanically ventilated room and the personal exposure to these contaminants. The study was performed in a full-scale climate chamber. The room was air conditioned via mixing total volume ventilation system. The room occupancy was ...... of the thermal manikin were measured. The results showed higher exposure to the contaminants measured at the breathing zone than at the ambient air. The behaviour of the tracer gas and the aerosols was similar.......The present study investigates the aerosol and gas dispersal in a mechanically ventilated room and the personal exposure to these contaminants. The study was performed in a full-scale climate chamber. The room was air conditioned via mixing total volume ventilation system. The room occupancy...... was simulated by a sitting dressed thermal manikin with realistic body shape. During the experiments monodisperse aerosols of three sizes and nitrous oxide tracer gas were generated simultaneously from one location in the room. The aerosol and gas concentrations in the bulk room air and in the breathing zone...

Bed Microenvironment in Hospital Patient Rooms with Natural or Mechanical Ventilation

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Li, Yuguo; Georgiev, Emanuil

2012-01-01

We studied how to provide patients in bed with thermally comfortable microenvironment in both naturally and mechanically ventilated hospital rooms for both winter and summer seasons. A climate chamber was used to resemble a hospital room and thermal manikin to simulate a patient lying in a bed...

Resistivity changes in superconducting-cavity-grade Nb following high-energy proton irradiation

International Nuclear Information System (INIS)

Snead, C.L. Jr.; Hanson, A.; Greene, G.A.

1997-01-01

Niobium superconducting rf cavities are proposed for use in the proton LINAC accelerators for spallation-neutron applications. Because of accidental beam loss and continual halo losses along the accelerator path, concern for the degradation of the superconducting properties of the cavities with accumulating damage arises. Residual-resistivity-ratio (RRR) specimens of Nb, with a range of initial RRR's were irradiated at room temperature with protons at energies from 200 to 2000 MeV. Four-probe resistance measurements were made at room temperature and at 4.2 K both prior to and after irradiation. Nonlinear increases in resistivity simulate expected behavior in cavity material after extended irradiation, followed by periodic anneals to room temperature: For RRR = 316 material, irradiations to (2 - 3) x 10 15 p/cm 2 produce degradations up to the 10% level, a change that is deemed operationally acceptable. Without. periodic warming to room temperature, the accumulated damage energy would be up to a factor of ten greater, resulting in unacceptable degradations. Likewise, should higher-RRR material be used, for the same damage energy imparted, relatively larger percentage changes in the RRR will result

Production of nanodiamonds by high-energy ion irradiation of graphite at room temperature

International Nuclear Information System (INIS)

Daulton, T.L.; Kirk, M.A.; Lewis, R.S.; Rehn, L.E.

2001-01-01

It has previously been shown that graphite can be transformed into diamond by MeV electron and ion irradiation at temperatures above approximately 600 deg. C. However, there exists geological evidence suggesting that carbonaceous materials can be transformed to diamond by irradiation at substantially lower temperatures. For example, submicron-size diamond aggregates have been found in uranium-rich, Precambrian carbonaceous deposits that never experienced high temperature or pressure. To test if diamonds can be formed at lower irradiation temperatures, sheets of fine-grain polycrystalline graphite were bombarded at 20 deg. C with 350±50 MeV Kr ions to fluences of 6x10 12 cm -2 using the Argonne tandem linear accelerator system (ATLAS). Ion-irradiated (and unirradiated control) graphite specimens were then subjected to acid dissolution treatments to remove untransformed graphite and isolate diamonds that were produced; these acid residues were subsequently characterized by high-resolution and analytical electron microscopy. The acid residue of the ion-irradiated graphite was found to contain nanodiamonds, demonstrating that ion irradiation of graphite at ambient temperature can produce diamond. The diamond yield under our irradiation conditions is low, ∼0.01 diamonds/ion. An important observation that emerges from comparing the present result with previous observations of diamond formation during irradiation is that nanodiamonds form under a surprisingly wide range of irradiation conditions. This propensity may be related to the very small difference in the graphite and diamond free-energies coupled with surface-energy considerations that may alter the relative stability of diamond and graphite at nanometer sizes

The Next Spaceflight Solar Irradiance Sensor: TSIS

Science.gov (United States)

Kopp, Greg; Pilewskie, Peter; Richard, Erik

2016-05-01

The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

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)

The edible gelatin irradiation sterilization technology and quality control

International Nuclear Information System (INIS)

Fu Junjie; Shi Jianjun; Shen Weiqiao

2000-01-01

60 Co γ-ray irradiation sterilization technology was used in treating edible gelatin and the irradiation effects on viscosity, protein and amino acid were studied. The results demonstrated that the irradiation dose had negative correlation with viscosity, and there were no damage effects on the gelatin with 360 days storage under room temperature. According to D 10 Value, the suitable irradiation dose should be 3-5 kGy

Dislocation defect interaction in irradiated Cu

International Nuclear Information System (INIS)

Schaeublin, R.; Yao, Z.; Spaetig, P.; Victoria, M.

2005-01-01

Pure Cu single crystals irradiated at room temperature to low doses with 590 MeV protons have been deformed in situ in a transmission electron microscope in order to identify the basic mechanisms at the origin of hardening. Cu irradiated to 10 -4 dpa shows at room temperature a yield shear stress of 13.7 MPa to be compared to the 8.8 MPa of the unirradiated Cu. Irradiation induced damage consists at 90% of 2 nm stacking fault tetrahedra, the remaining being dislocation loops and unidentified defects. In-situ deformation reveals that dislocation-defect interaction can take several forms. Usually, dislocations pinned by defects bow out under the applied stress and escape without leaving any visible defect. From the escape angles obtained at 183 K, an average critical stress of 100 MPa is deduced. In some cases, the pinning of dislocations leads to debris that are about 20 nm long, which formation could be recorded during the in situ experiment

Treatment of tannery effluent by irradiation. [gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Roszak, W; Pekala, W

1983-01-01

Different samples of tannins were exposed to gamma radiation at room temperature. Some of them were aerated during irradiation.In irradiated samples the concentration of phenol and organic substances decreased and their biodegradability increased. Aerated samples had a higher decrease of phenol concentration. (E.G.M.).

Effect of 120 MeV Ag{sup 9+} ion irradiation of YCOB single crystals

Energy Technology Data Exchange (ETDEWEB)

Arun Kumar, R., E-mail: rarunpsgtech@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600 025 (India); Department of Basic Sciences - Physics Division, PSG College of Technology, Coimbatore 641 004 (India); Dhanasekaran, R. [Crystal Growth Centre, Anna University, Chennai 600 025 (India)

2012-09-15

Single crystals of yttrium calcium oxy borate (YCOB) grown from boron-tri-oxide flux were subjected to swift heavy ion irradiation using silver Ag{sup 9+} ions from the 15 UD Pelletron facility at Inter University Accelerator Center, New Delhi. The crystals were irradiated at 1 Multiplication-Sign 10{sup 13}, 5 Multiplication-Sign 10{sup 13} and 1 Multiplication-Sign 10{sup 14} ions/cm{sup 2} fluences at room temperature and with 5 Multiplication-Sign 10{sup 13} ions/cm{sup 2} fluence at liquid nitrogen temperature. The pristine and the irradiated samples were characterized by glancing angle X-ray diffraction, UV-Vis-NIR and photoluminescence studies. From the characterization studies performed on the samples, it is inferred that the crystals irradiated at liquid nitrogen temperature had fewer defects compared to the crystals irradiated at room temperature and the defects increased when the ion fluence was increased at room temperature.

Comparison of hospital room surface disinfection using a novel ultraviolet germicidal irradiation (UVGI) generator.

Science.gov (United States)

Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

2016-09-01

The estimated 721,800 hospital acquired infections per year in the United States have necessitated development of novel environmental decontamination technologies such as ultraviolet germicidal irradiation (UVGI). This study evaluated the efficacy of a novel, portable UVGI generator (the TORCH, ChlorDiSys Solutions, Inc., Lebanon, NJ) to disinfect surface coupons composed of plastic from a bedrail, stainless steel, chrome-plated light switch cover, and a porcelain tile that were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE). Each surface type was placed at 6 different sites within a hospital room and treated by 10-min ultraviolet-C (UVC) exposures using the TORCH with doses ranging from 0-688 mJ/cm(2) between sites. Organism reductions were compared with untreated surface coupons as controls. Overall, UVGI significantly reduced MRSA by an average of 4.6 log10 (GSD: 1.7 log10, 77% inactivation, p surfaces, while VRE was reduced significantly less on chrome (p = 0.0004) and stainless steel (p = 0.0012) than porcelain tile. Organisms out of direct line of sight of the UVC generator were reduced significantly less (p surfaces evaluated within the hospital environment in direct line of sight of UVGI treatment with variation between organism and surface types.

Effect of radiation on the nutritive value of post irradiated potatoes

International Nuclear Information System (INIS)

Pringsulaka, Vachira.

1983-12-01

Harvested fresh potatoes of Spunta variety, were irradiated at 0, 60, 90, 120 and 150 gray and then stored at three temperatures; room temperature (30+-5 deg C) with 55-65 percent R.H., and 15 deg C and 10 deg C both with 85-95 percent R.H. The biochemical assay of total sugar, protein, and vitamin C were conducted for the determination of changing in nutritive value. The results of the experiment are as follows. Both non-irradiated and irradiated potatoes, stored at room temperature with 55-65 percent R.H., showed higher changing in percentage of total sugar and vitamin C, but only slightly changing in protein was observed. Furthermore, no significant difference was found in nutritive value between irradiated and non-irradiated potatoes stored at 15 deg C and 10 deg C with 85-95 percent R.H

Irradiation of onions with the commercial potato irradiator

International Nuclear Information System (INIS)

Aoki, Shohei; Kawashima, Koji; Hayasi, Toru

1983-01-01

Three varieties of onion harvested in Hokkaido were irradiated with the Shohoro Potato Irradiator on 29th September, 1981. One ton of each of the varieties, Kitamiki (KI), Ohohtsuku (OH) and Furanui (FU), was used in this investigation. Onions had longer dormancy period in the order of FU>OH>KI. Higher sprouting percentage was obtained in the unirradiated onions, while they were stored at a higher temperature or stored for a longer period. Generally, unirradiated onions sprouted before they were deteriorated. Thus the number of deteriorated bulbs in the unirradiated onions was superficially less than that in the irradiated ones. When the onions which were taken from warehouses on 26th March, 1982 were stored at room temperature, the percentage of wholesome bulbs was higher in KI and OH than FU. Small buds in some of the irradiated onions turned dark after a long storage time. Quantitative estimation of this phenomena is left to be resolved. There was little relationship between the weight loss and the number of wholesome onions. (author)

Nuclear prehistory influence on irradiated metallic iron phase composition

International Nuclear Information System (INIS)

Alekseev, I.E.

2007-01-01

With application of different Moessbauer spectroscopy applications the phase composition of metallic iron after irradiation by both neutrons and charged particles were studied. Irradiation conditions, method of targets examination and phase composition of samples after irradiation were presented in tabular form. It is shown, that phase composition of irradiated metal is defined by nuclear prehistory. So, in a number of cases abnormals (stabilization of high- and low-temperature structural phases of iron at room temperature after irradiation end) were revealed

β-ray irradiation effects in RbBr: Eu crystals

International Nuclear Information System (INIS)

Pacheco B, J.M.; Rodriguez M, R.; Perez S, R.

2006-01-01

Defects induced by β-ray irradiation in RbBr: Eu 2+ crystals doped with a high concentration of Eu 2+ ions are studied by means of optical absorption (OA), thermoluminescence (TL), and optically stimulated TL (OSTL). The fading, dose, and optical bleaching effects on the TL glow curves of room temperature irradiated samples has been analyzed. OA indicates that irradiation of samples at room temperature induce the formation of F but not F z centers. The TL glow curves show peaks at 267, 303, and 403 K. The 267 K glow peak disappear in less than 1 s under blue light or infrared radiation photo bleaching. A high sensitivity to the ionizing radiation has been observed. These results confirm that this material is an efficient phosphor. (Author)

Simulation of a room for neutron instrument calibration at LCR/UERJ

International Nuclear Information System (INIS)

Medeiros, M.P.C.; Estrada, J.J.S.; Gomes, R.G.; Santos, R.F.G.; Leite, S.P.; Alves, C.F.E.; Rebello, W.F.; Almeida, C.E. de

2013-01-01

In this work the MCNPX code was used to design a calibrating room for neutron detectors to be implemented in the Laboratorio de Ciencias Radiologicas of UERJ. The calibration room containing a neutron irradiator with a 241 Am-Be source, a linear positioning system, radiation detectors and a shadow cone was modeled. The ambient dose equivalent rate, ııı ∗ ı10ı, in adjacent to the calibration room areas, as well as neutron scattering caused by the room itself were calculated. Using an occupancy factor of 1/16 for all adjacent areas, 3.8 cm of 5% borated polyethylene or 5.5 cm of concrete for shielding is enough to satisfy radiation safety requirements. (author)

A comparison of methods to estimate daily global solar irradiation from other climatic variables on the Canadian prairies

International Nuclear Information System (INIS)

Barr, A.G.; McGinn, S.M.; Cheng, S.B.

1996-01-01

Historic estimates of daily global solar irradiation are often required for climatic impact studies. Regression equations with daily global solar irradiation, H, as the dependent variable and other climatic variables as the independent variables provide a practical way to estimate H at locations where it is not measured. They may also have potential to estimate H before 1953, the year of the first routine H measurements in Canada. This study compares several regression equations for calculating H on the Canadian prairies. Simple linear regression with daily bright sunshine duration as the dependent variable accounted for 90% of the variation of H in summer and 75% of the variation of H in winter. Linear regression with the daily air temperature range as the dependent variable accounted for 45% of the variation of H in summer and only 6% of the variation of H in winter. Linear regression with precipitation status (wet or dry) as the dependent variable accounted for only 35% of the summer-time variation in H, but stratifying other regression analyses into wet and dry days reduced their root-mean-squared errors. For periods with sufficiently dense bright sunshine observations (i.e. after 1960), however, H was more accurately estimated from spatially interpolated bright sunshine duration than from locally observed air temperature range or precipitation status. The daily air temperature range and precipitation status may have utility for estimating H for periods before 1953, when they are the only widely available climatic data on the Canadian prairies. Between 1953 and 1989, a period of large climatic variation, the regression coefficients did not vary significantly between contrasting years with cool-wet, intermediate and warm-dry summers. They should apply equally well earlier in the century. (author)

Experimental studies on the effect of perfluorochemicals in tumor irradiation

International Nuclear Information System (INIS)

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

1984-01-01

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

Dose rate distribution of the GammaBeam: 127 irradiator using MCNPX code

International Nuclear Information System (INIS)

Gual, Maritza Rodriguez; Batista, Adriana de Souza Medeiros; Pereira, Claubia; Faria, Luiz O. de; Grossi, Pablo Andrade

2013-01-01

The GammaBeam - 127 Irradiator is widely used for biological, chemical and medical applications of the gamma irradiation technology using Cobalt 60 radioactive at the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The source has maximum activity of 60.000Ci, which is composed by 16 double encapsulated radioactive pencils placed in a rack. The facility is classified by the IAEA as Category II (dry storage facility). The aim of this work is to present a modelling developed to evaluate the dose rates at the irradiation room and the dose distribution at the irradiated products. In addition, the simulations could be used as a predictive tool of dose evaluation in the irradiation facility helping benchmark experiments in new similar facilities. The MCNPX simulated results were compared and validated with radiometric measurements using Fricke and TLDs dosimeters along several positions inside the irradiation room. (author)

Sensitivity of Listeria monocytogenes to irradiation

International Nuclear Information System (INIS)

Tarjan, Veronika

1990-01-01

Irradiation of Listeria monocytogenes (L.m.) was carried out in culture media and pork meat paste at room temperature with 60 Co radiation source of 6.6 kGy h -1 dose rate. The employed doses were 0, 0.5, 1, 2, 3, 4 and 6 kGy. One strain out of 3 survived as high as 4 kGy irradiation. Radiation with 2 kGy resulted 7 log cycles reduction of cell count. After lower irradiation doses the L.m. count decreased in proportion to increasing doses. It has been concluded that L.m. compared with Gram-negative pathogens, are less sensitive to irradiation. (author) 6 refs.; 4 figs

Sprouting inhibition of rhizomes by gamma irradiation

International Nuclear Information System (INIS)

Hilmy, Nazly; Chosdu, Rahayu

1985-01-01

Sprouting inhibition by gamma irradiation to prolong the storage life of 4 species of rhizomes, namely curcuma domestica, kaemferia galanga, curcuma xanthoriza and curcuma aeruginosa, has been carried out. Two groups of samples were used, freshly harvested rhizomes and fresh rhizomes which have been stored for about two weeks. The samples were packed in a plastic net bag, each contained about 100 grams of rhizomes. Irradiation was carried out at room temperature at the doses of 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.15, 0.20 and 0.25 kGy. Post irradiation storage was done at room temperature with relative humidity ranging between 85 and 95%. The results showed that irradiation doses of 0.06 to 0.08 kGy was sufficient to inhibit sprouting of freshly harvested rhizomes and prolonged its storage life for 6 weeks, while in the other group sprouting still occured at the dose of 0.25 kGy. Irradiation dose up to 0.25 kGy did not cause significant effect on moisture and volatile oil contents, as well as volatile oil characteristics of the samples. About 50% of weight losses were found either in irradiated or unirradiated samples after being stored for 8 weeks. Odour and texture were evaluated organoleptically while mould growth and insect damage were observed visually. (author)

Fast neutron spectrum in the exposure room of the TRIGA Mark II reactor in Ljubljana

International Nuclear Information System (INIS)

Kristof, E.S.

2003-01-01

In this paper a description of the high energy neutrons at a usual position in the dry cell of our reactor is given. Neutrons emerging from the graphite reflector enter the exposure room through the horizontal shaft. At the irradiation position samples of detection materials were irradiated. After irradiation γ-ray spectra were measured and from the saturation activities the spectrum was calculated. (author)

An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra.

Science.gov (United States)

Hogewoning, Sander W; Douwstra, Peter; Trouwborst, Govert; van Ieperen, Wim; Harbinson, Jeremy

2010-03-01

Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner. Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra. Whereas specific responses of plants to a spectrum differing from natural daylight may sometimes be predictable, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses. So far studies on plant responses to spectra either use no daylight control or, if a natural daylight control is used, it will fluctuate in intensity and spectrum. An artificial solar (AS) spectrum which closely resembles a sunlight spectrum has been engineered, and growth, morphogenesis, and photosynthetic characteristics of cucumber plants grown for 13 d under this spectrum have been compared with their performance under fluorescent tubes (FTs) and a high pressure sodium lamp (HPS). The total dry weight of the AS-grown plants was 2.3 and 1.6 times greater than that of the FT and HPS plants, respectively, and the height of the AS plants was 4-5 times greater. This striking difference appeared to be related to a more efficient light interception by the AS plants, characterized by longer petioles, a greater leaf unfolding rate, and a lower investment in leaf mass relative to leaf area. Photosynthesis per leaf area was not greater for the AS plants. The extreme differences in plant response to the AS spectrum compared with the widely used protected cultivation light sources tested highlights the importance of a more natural spectrum, such as the AS spectrum, if the aim is to produce plants representative of field conditions.

Formation of uranium based nanoparticles via gamma-irradiation

Energy Technology Data Exchange (ETDEWEB)

Nenoff, Tina M., E-mail: tmnenof@sandia.gov [Nanoscale Sciences Department, Sandia National Laboratories, P.O. Box 5800, MS-1415, Albuquerque, NM 87185 (United States); Ferriera, Summer R. [Nanoscale Sciences Department, Sandia National Laboratories, P.O. Box 5800, MS-1415, Albuquerque, NM 87185 (United States); Huang, Jianyu [Center for Integrated Nanotechnology, Sandia National Laboratories, P.O. Box 5800, MS-1315, Albuquerque, NM 87185 (United States); Hanson, Donald J. [Department of Hot Cells and Gamma Facilities, Sandia National Laboratories, P.O. Box 5800, MS-1143, Albuquerque, NM 87185 (United States)

2013-11-15

Graphical abstract: TEM image of d-U nanoparticles formed in aqueous solution by gamma irradiation. Display Omitted -- Highlights: •d-U nanoparticles were grown in solution by gamma irradiation. •The reaction solution does not exceed 25 °C (room temperature). •Only after multiday exposure to air is there evidence of oxidation of the d-U nanoparticles. •Evidence of d-U alloy nanoparticle formation confirmed by TEM/energy-dispersive X-ray (EDS) analysis. -- Abstract: The ability to fabricate nuclear fuels at low temperatures allows for the production of complex Uranium metal and alloys with minimum volatility of alloy components in the process. Gamma irradiation is a valuable method for the synthesis of a wide range of metal-based nanoparticles. We report on the synthesis via room temperature radiolysis and characterization of uranium (depleted, d-U) metal and uranium–lathanide (d-ULn, Ln = lanthanide surrogates) alloy nanoparticles from aqueous acidic salt solutions. The lanthanide surrogates chosen include La and Eu due to their similarity in ionic size and charge in solution. Detailed characterization results including UV–vis, TEM/HR-TEM, and single particle EDX (elemental analyses) are presented for the room temperature formed nanoparticle products.

Formation of uranium based nanoparticles via gamma-irradiation

International Nuclear Information System (INIS)

Nenoff, Tina M.; Ferriera, Summer R.; Huang, Jianyu; Hanson, Donald J.

2013-01-01

Graphical abstract: TEM image of d-U nanoparticles formed in aqueous solution by gamma irradiation. Display Omitted -- Highlights: •d-U nanoparticles were grown in solution by gamma irradiation. •The reaction solution does not exceed 25 °C (room temperature). •Only after multiday exposure to air is there evidence of oxidation of the d-U nanoparticles. •Evidence of d-U alloy nanoparticle formation confirmed by TEM/energy-dispersive X-ray (EDS) analysis. -- Abstract: The ability to fabricate nuclear fuels at low temperatures allows for the production of complex Uranium metal and alloys with minimum volatility of alloy components in the process. Gamma irradiation is a valuable method for the synthesis of a wide range of metal-based nanoparticles. We report on the synthesis via room temperature radiolysis and characterization of uranium (depleted, d-U) metal and uranium–lathanide (d-ULn, Ln = lanthanide surrogates) alloy nanoparticles from aqueous acidic salt solutions. The lanthanide surrogates chosen include La and Eu due to their similarity in ionic size and charge in solution. Detailed characterization results including UV–vis, TEM/HR-TEM, and single particle EDX (elemental analyses) are presented for the room temperature formed nanoparticle products

EPR investigation of some traditional oriental irradiated spices

International Nuclear Information System (INIS)

Duliu, Octavian G.; Georgescu, Rodica; Ali, Shaban Ibrahim

2007-01-01

The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and 60 Co γ-ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), and saffron (Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After γ-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 o C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices

EPR investigation of some traditional oriental irradiated spices

Science.gov (United States)

Duliu, Octavian G.; Georgescu, Rodica; Ali, Shaban Ibrahim

2007-06-01

The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and 60Co γ-ray irradiated cardamom ( Elettaria cardamomum L. Maton, Zingiberaceae), ginger (( Zingiber officinale Rosc., Zingiberaceae), and saffron ( Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After γ-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 °C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices.

Cosmic rays and climate

CERN Multimedia

CERN. Geneva

2009-01-01

The current understanding of climate change in the industrial age is that it is predominantly caused by anthropogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. However, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming - and yet the mechanism or mechanisms are not understood. Some of these reconstructions show clear associations with solar variability, which is recorded in the light radio-isotope archives that measure past variations of cosmic ray intensity. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Estimated changes of solar irradiance on these time scales appear to be too small to account for the climate observations. This raises the question of whether cosmic rays may directly affect the climate, provi...

Effect of Fast Neutron Irradiation on Current Transport Properties of HTS Materials

CERN Document Server

Ballarino, A; Kruglov, V S; Latushkin, S T; Lubimov, A N; Ryazanov, A I; Shavkin, S V; Taylor, T M; Volkov, P V

2004-01-01

The effect of fast neutron irradiation with energy up to 35 MeV and integrated fluence of up to 5 x 10**15 cm-2 on the current transport properties of HTS materials Bi-2212 and Bi-2223 has been studied, both at liquid nitrogen and at room temperatures. The samples irradiated were selected after verification of the stability of their superconducting properties after temperature cycling in the range of 77 K - 293 K. It has been found that the irradiation by fast neutrons up to the above dose does not produce a significant degradation of critical current. The effect of room temperature annealing on the recovery of transport properties of the irradiated samples is also reported, as is a preliminary microstructure investigation of the effect of irradiation on the soldered contacts.

Effect of pre-stressing on the behaviour of CFRP under gamma irradiation

International Nuclear Information System (INIS)

Burnay, S.G.

1992-01-01

The effect of pre-stressing on the behaviour of CFRP composites under gamma irradiation has been studied for three materials: 0 deg carbon/epoxy, 0 deg carbon/toughened epoxy and 0 deg/90 deg carbon/PES. Irradiation was carried out at room temperature and at 77 K. Preliminary results illustrate that pre-stressing can significantly affect the degradation of these materials, particularly after irradiation at room temperature. The data indicate that stress cannot be ignored when assessing the durability of structural composites for space applications. This work, which completes the preliminary assessment of low-temperature irradiation effects, has highlighted a number of queries which should be of concern to those using structural composites in space applications. (Author). 15 refs., 17 figs

Irradiation detection of coffee mate by electron spin resonance (ESR)

Energy Technology Data Exchange (ETDEWEB)

Ozsayin, Fulya [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey); Polat, Mustafa, E-mail: polat@hacettepe.edu.t [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey)

2011-06-15

Un-irradiated coffee mate samples do not exhibit any ESR signal. However, the samples exposed to UV and gamma radiation exhibit an ESR singlet and a large unresolved ESR signal, respectively. The dose-response curves of the samples exposed to UV and gamma radiations were found to be described well by an exponential and linear functions, respectively. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in coffee mate sample are very sensitive to temperature. The discrimination between un-irradiated and irradiated coffee mate samples can be done just comparing their ESR spectra. However, determination of the radiation dose received by the sample cannot be possible because of the fast decay of signal intensity at room temperature.

Room temperature Q-band electron magnetic resonance study of radicals in X-ray-irradiated L-threonine single crystals

International Nuclear Information System (INIS)

Vanhaelewyn, Gauthier; Vrielinck, Henk; Callens, Freddy

2014-01-01

In the past, decennia radiation-induced radicals were successfully identified by electron magnetic resonance (EMR) in several solid-state amino acids and sugars. The authors present a room temperature (RT) EMR study of the stable radicals produced by X-ray-irradiation in the amino acid L-threonine (CH 3 CH(OH)CH(NH3 + )COO - ). Its chemical structure is similar to that of the well-known dosimetric material L-alanine (CH 3 CH(NH3 + )COO - ), and radiation defects in L-threonine may straightforwardly be compared with the extensively studied L-alanine radicals. The hyperfine coupling tensors of three different radicals were determined at RT using electron nuclear double resonance. These results indicate that the two most abundant radicals share the same basic structure CH 3 .C(OH)CH(NH3 + )COO - , obtained by H-abstraction, but are stabilised in slightly different conformations. The third radical is most probably obtained by deamination (CH 3 CH(OH).CHCOO - ), similar in structure to the stable alanine radical. (authors)

SORCE: Solar Radiation and Climate Experiment

Science.gov (United States)

Cahalan, Robert; Rottman, Gary; Lau, William K. M. (Technical Monitor)

2002-01-01

Contents include the following: Understanding the Sun's influence on the Earth; How the Sun affect Earth's climate; By how much does the Sun's radiation very; Understanding Solar irradiance; History of Solar irradiance observations; The SORCE mission; How do the SORCE instruments measure solar radiation; Total irradiance monitor (TIM); Spectral irradiance monitor (SIM); Solar stellar irradiance comparison experiment (SOLSTICE); XUV photometer system (XPS).

Study on irradiation of freshening ginseng and toxicity test

International Nuclear Information System (INIS)

Wang Ziwen; Xu Dechun; Yang Wanqi

1991-01-01

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

Gamma-irradiation of tomatoes

International Nuclear Information System (INIS)

Tencheva, S.; Todorov, S.

1975-01-01

The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

The effect of composition, electron irradiation and quenching on ...

Indian Academy of Sciences (India)

The ionic conductivity at room temperature exhibits a characteristic double peak for the composition = 20 and 70. Both electron beam irradiation and quenching at low temperature have resulted in an increase in conductivity by 1–2 orders of magnitude. The enhancement of conductivity upon irradiation and quenching is ...

X radiations dosimetry in pulmonary radiographs: study of a non standard room

International Nuclear Information System (INIS)

Bied, J.C.; Philippon, B.

1998-01-01

A radiograph room can present a default of radiation protection. But it is possible that the radiation protection is here only to mask a protection of an other type. For the case of a lungs type radiograph room, the monitoring does not reveal any problem of radiation protection. These results do not bring to the fore any high radiations doses. But they are an illustration of operators positions, and these ones should be better protected at the extremity of the room, that should allow a correct vision of lungs radiographs and a more important limitation of irradiation. (N.C.)

Study on the storage properties of irradiated ginger

International Nuclear Information System (INIS)

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

2004-01-01

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

Irradiation effects on the mechanical properties of composite organic insulators

International Nuclear Information System (INIS)

Egusa, S.; Kirk, M.A.; Birtcher, R.C.; Hagiwara, M.; Kawanishi, S.

1983-01-01

Four kinds of cloth-filled organic composites (filler: glass or carbon fiber; matrix: epoxy or polymide resin) were irradiated with 2-MeV electrons at room temperature, and were examined with regard to the mechanical properties. Following irradiation, the Young's (tensile) modulus of these composites remains practically unchanged even after irradiation up to 15,000 Mrad. The shear modulus and the ultimate strength, on the other hand, begin to decrease after the absorbed dose reaches about 2000 Mrad for the glass/epoxy composite and about 5000 approx. 10,000 Mrad for the other composites. This result is ascribed to the decrease in the capacity of load transfer from the matrix to the fiber due to the radiation-induced debonding at the interface. As to the fracture behavior, the propagation energy increases from the beginning of irradiation. This result is attributed to the radiation-induced decrease in the bonding energy at the interface. The same study was made also for these composites and an alumina fiber-epoxy composite irradiated with fast neutrons at room temperature and 5 0 K. 7 figures, 1 table

Irradiation effect of the insulating materials for fusion superconducting magnets at cryogenic temperature

Science.gov (United States)

Kobayashi, Koji; Akiyama, Yoko; Nishijima, Shigehiro

2017-09-01

In ITER, superconducting magnets should be used in such severe environment as high fluence of fast neutron, cryogenic temperature and large electromagnetic forces. Insulating material is one of the most sensitive component to radiation. So radiation resistance on mechanical properties at cryogenic temperature are required for insulating material. The purpose of this study is to evaluate irradiation effect of insulating material at cryogenic temperature by gamma-ray irradiation. Firstly, glass fiber reinforced plastic (GFRP) and hybrid composite were prepared. After irradiation at room temperature (RT) or liquid nitrogen temperature (LNT, 77 K), interlaminar shear strength (ILSS) and glass-transition temperature (Tg) measurement were conducted. It was shown that insulating materials irradiated at room temperature were much degraded than those at cryogenic temperature.

Storage properties of gamma-irradiated semi-dried fish varieties

International Nuclear Information System (INIS)

Vinh, P.Q.; Alur, M.D.; Nair, P.M.

1993-01-01

Several varieties of semi-dried unirradiated and irradiated (1 and 3 kGy) fish, namely, anchovies (Stolephorus commersonii), Bombay duck (Harpodon nehereus), shrimp (Penaeus indicus) and Vietnam scad (Alepes mate) were stored at ambient temperature (26 degree C). During the course of storage, quality characteristics such as total bacterial count (TBC), mould count and biochemical indices of freshness were studied. These studies indicated that initial TBC of semi-dried fish varied from 700-5400 cfu per g of fish, while mould could ranged from 27-1500 cfu per g. However, upon irradiation at 3 kGy, initial bacterial load was considerably reduced. Vietnam scad was not contaminated with mould after 3-5 months of storage at room temperature. Indices such as TVA and TVBN increased during storage at room temperature for both unirradiated and irradiated samples

Perceived Air Quality in a Displacement Ventilated Room

DEFF Research Database (Denmark)

Brohus, Henrik; Knudsen, Henrik Nellemose; Nielsen, Peter V.

in a displacement ventilated room was determined directly by asking humans about how they perceived the air quality. A trained sensory panel comprising 12 subjects assessed the perceived air quality immediately after entering a climate chamber. The experiments showed that the perceived air quality...

EPR investigation of some traditional oriental irradiated spices

Energy Technology Data Exchange (ETDEWEB)

Duliu, Octavian G. [University of Bucharest, Department of Atomic and Nuclear Physics, Magurele, C.P. MG-11, RO-077125 Bucharest (Romania)]. E-mail: duliu@pcnet.ro; Georgescu, Rodica [National Institute for Physics and Nuclear Engineering -Horia Hulubei, C.P. MG-6, RO-077125 Bucharest (Romania); Ali, Shaban Ibrahim [University of Bucharest, Department of Atomic and Nuclear Physics, Magurele, C.P. MG-11, RO-077125 Bucharest (Romania)

2007-06-15

The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and {sup 60}Co {gamma}-ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), and saffron (Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After {gamma}-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 {sup o}C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices.

Behaviour of the activity of cellulase irradiated under various conditions

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1988-01-01

The activity of cellulase irradiated at various conditions has been studied. The activity of cellulase irradiated at low temperature (-78 0 C) increased by heating at 40 0 C, but that of cellulase irradiated at high temperature above 0 0 C decreased. The activity of cellulase irradiated in the dry state at room temperature increased with irradiation dose. The effect of adding biological substances such as amino acids, enzymes, and agar on the irradiation of cellulase was studied. It was shown that EDTA and p-benzoquinone have a protective ability against radiation-induced inactivation of the enzyme. (author)

Behaviour of the activity of cellulase irradiated under various conditions

Energy Technology Data Exchange (ETDEWEB)

Kumakura, M; Kaetsu, I

1988-04-18

The activity of cellulase irradiated at various conditions has been studied. The activity of cellulase irradiated at low temperature (-78 /sup 0/C) increased by heating at 40 /sup 0/C, but that of cellulase irradiated at high temperature above 0 /sup 0/C decreased. The activity of cellulase irradiated in the dry state at room temperature increased with irradiation dose. The effect of adding biological substances such as amino acids, enzymes, and agar on the irradiation of cellulase was studied. It was shown that EDTA and p-benzoquinone have a protective ability against radiation-induced inactivation of the enzyme.

Climate control of a bulk storage room for foodstuffs

NARCIS (Netherlands)

Mourik, van S.; Zwart, H.; Keesman, K.J.

2006-01-01

A storage room contains a bulk of agricultural products, such as potatoes, onions, fruits, etcetera. The products produce heat due to respiration, see for example [1, 2]. A ventilator blows cooled air around to keep the products at a steady temperature and prevent spoilage. The aim is to design a

Ionic conductivity in irradiated KCL

International Nuclear Information System (INIS)

Vignolo Rubio, J.

1979-01-01

The ionic conductivity of X and gamma irradiated KCl single crystals has been studied between room temperature and 600 deg C. The radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 deg C respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. Howewer, it has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that small radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (auth)

Ionic conductivity in irradiated KCL

International Nuclear Information System (INIS)

Vignolo Rubio, J.

1979-01-01

The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

Positron annihilation measurements in high-energy alpha-irradiated n-type gallium arsenide

Energy Technology Data Exchange (ETDEWEB)

Pan, Sandip; Mandal, Arunava; SenGupta, Asmita [Visva-Bharati, Department of Physics, Santiniketan, West Bengal (India); Roychowdhury, Anirban [UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata, West Bengal (India)

2015-07-15

Positron annihilation lifetime spectroscopy and Doppler broadening annihilation line-shape measurements have been carried out in 40-MeV alpha-irradiated n-type GaAs. After irradiation, the sample has been subjected to an isochronal annealing over temperature region of 25-800 C with an annealing time of 30 min at each set temperature. After each annealing, the positron measurements are taken at room temperature. Formation of radiation-induced defects and their recovery with annealing temperature are investigated. The lifetime spectra of the irradiated sample have been fitted with two lifetimes. The average positron lifetime τ{sub avg} = 244 ps at room temperature after irradiation indicates the presence of defects, and the value of τ{sub 2} (262 ps) at room temperature suggests that the probable defects are mono-vacancies. Two distinct annealing stages in τ{sub avg} at 400-600 C and at 650-800 C are observed. The variations in line-shape parameter (S) and defect-specific parameter (R) during annealing in the temperature region 25-800 C resemble the behaviour of τ{sub avg} indicating the migration of vacancies, formation of vacancy clusters and the disappearance of defects between 400 and 800 C. (orig.)

Study on irradiated polymerization of acrylonitrile by NMR

International Nuclear Information System (INIS)

Zhao Xin; Lin Hao

1999-01-01

Sup 13 C CP/MAS spectra and nuclear Overhauser effects (NOE) at room temperature have been measured for acrylonitrile (AN) in homophase irradiated polymerization. With the increase of radiation dose the chemical shift of cracking peaks and NOE are variation. This implies that the polymerized mechanism of AN were changed with the variation of irradiated doses and dose rate. There is the stronger affinity electron group (-CN) in acrylonitrile monomer. It may be polymerized by various ways and mechanism and be gained the polymer of difference structures and molecular weight of polyacrylonitrile (PAN). Starmicarbon and Starker obtained higher molecular weight of polyacrylonitrile by peroxysulfate-pyrosulfite in oxidation-reduction system. The superhigh molecular weight of PAN was synthesized chemically according to the method of Wu et. al. by suspension polymerization. In this paper we discussed that the relative concentrations of steric dyads and triads in the chain structure in PAN and the irradiation polymerized mechanism of acrylonitrile monomer in room temperature by different dose and dose rate

Effects of irradiation on the volatile compounds of garlic (Allium sativum L)

International Nuclear Information System (INIS)

Wu, J.J.; Yang, J.S.; Liu, M.S.

1996-01-01

The effects of 0.15 kGy gamma irradiation on the content of volatile compounds in garlic bulbs during storage at room temperature were evaluated. The content of diallyl disulphide decreased immediately after irradiation. However, at the end of 8-month storage both irradiated and unirradiated samples showed a significant increase in diallyl disulphide

New irradiation facilities at the Australian national medical cyclotron

International Nuclear Information System (INIS)

Parcell, S.K.; Arnott, D.W.; Conard, E.M.

1999-01-01

Two new irradiation facilities have been developed at the National Medical Cyclotron for radionuclide production. The first relocates PET irradiations from the cyclotron vault to a dedicated PET beam room, to improve accessibility and reduce radiation exposures associated with target maintenance. This new facility consists of a beam line to transport 16-30 MeV proton beams from the cyclotron to 1 of 8 PET targets mounted on a target rack. The target rack has increased the number of targets available for production and experimentation. The second is a completely independent solid target irradiation facility for SPECT. This facility consists of a beam line to transport 26-30 MeV proton beams from the cyclotron to a dedicated beam room containing one solid target station. A new pneumatic target transfer system was also developed to transport the solid target to and from the existing chemistry hot cells. The beam line and target components are operated under the control of a dedicated PLC with a PC based user interface. The development and some technical aspects of these new irradiation facilities are discussed here. (author)

Spallation and 14-MeV neutron irradiation of stabilized NbTi superconductors

International Nuclear Information System (INIS)

Hahn, P.; Brown, B.S.; Weber, H.W.; Guinan, M.W.

1983-08-01

The results on 5 K irradiation available so far may be summarized as follows. (1) Increases of j/sub c/ following neutron irradiation occur only in conductors which are far from the optimal metallurgical treatments. (2) The changes of j/sub c/ following neutron irradiation and a thermal cycle to room temperature are small and in most cases comparable to the results obtained after 77 K irradiation. (3) The data available so far indicate that the degradation of j/sub c/ at 8 T is larger by about 5 to 10% than the corresponding changes at 5 T at a neutron fluence of 1.3 x 10 22 m -2 (E > 0.1 MeV). (4) The increase of Cu-resistivity is significant even after a thermal cycle to room temperature and requires design changes for a stable magnet operation

Mechanical properties of irradiated beryllium

International Nuclear Information System (INIS)

Beeston, J.M.; Longhurst, G.R.; Wallace, R.S.

1992-01-01

Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10 25 n/m 2 (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.)

Mechanical properties of irradiated beryllium

Energy Technology Data Exchange (ETDEWEB)

Beeston, J.M.; Longhurst, G.R.; Wallace, R.S. (EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.); Abeln, S.P. (EG and G Rocky Flats, Inc., Golden, CO (United States))

1992-10-01

Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10[sup 25] n/m[sup 2] (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.).

Mechanical properties of irradiated beryllium

Science.gov (United States)

Beeston, J. M.; Longhurst, G. R.; Wallace, R. S.; Abeln, S. P.

1992-10-01

Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 × 10 25 n/m 2 ( E > 1 MeV) at an irradiation temperature of 75°C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium.

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)

Effect of autoclave processing and gamma irradiation on apparent ...

African Journals Online (AJOL)

The objective of this study was to investigate the effect of autoclaving and different doses of gamma irradiation on the apparent ileal digestibility of amino acids of cottonseed meal in male broiler breeders. Samples were irradiated in a gamma cell at total doses of 15, 30 and 45 kGy. One package (control) was left at room ...

Electron-beam irradiation effects on mechanical properties of PEEK/CF composite

International Nuclear Information System (INIS)

Sasuga, Tsuneo; Seguchi, Tadao

1989-01-01

Carbon fibre-reinforced composite (PEEK/CF) using polyarylether-ether-ketone (PEEK) as a matrix material was prepared and electron-beam irradiation effects on the mechanical properties at low and high temperatures were studied. The flexural strength and modulus of the unirradiated PEEK/CF were almost the same as those of carbon fibre-reinforced composites with epoxide resin. The mechanical properties at room temperature were little affected by irradiation up to 180 MGy, but in the test at 77K the strength of the specimens irradiated over 100 MGy was slightly decreased. The mechanical properties of the unirradiated specimen decreased with increasing testing temperature, but the high-temperature properties were improved by irradiation, i.e. the strength measured at 413K for the specimen irradiated with 120 MGy almost reached the value for the unirradiated specimen measured at room temperature. It was apparent from the viscoelastic measurement that the improvement of mechanical properties at high temperature resulted from the high-temperature shift of the glass transition of the matrix PEEK caused by radiation-induced cross-linking. (author)

Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

International Nuclear Information System (INIS)

Yu, H.; Yao, Z.; Kirk, M.A.; Daymond, M.R.

2015-01-01

In situ heavy ion irradiation with 1 MeV Kr"2"+ was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 "oC or 450 "oC. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 "oC irradiation but not at 450 "oC. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2 and both present in β-Zr under room temperature irradiation. (author)

Is There Room for Coherence in Climate Financial Assistance?

Directory of Open Access Journals (Sweden)

Laurence Boisson de Chazournes

2015-08-01

Full Text Available This article takes a closer look at the complex web of financial assistance mechanisms in the climate change sector. These mechanisms are important tools for assisting developing countries to address the challenges associated with climate change. Mapping the various types of institutions and funds in this sector, the author underlines the important role played by the private sector but also highlights the increasing presence of financial mechanisms under the aegis of international organizations, such as the World Bank. Moreover, a particular focus is placed on the Green Climate Fund and the way in which the establishment of this mechanism may affect the functioning of existing financial mechanisms. In calling for better communication, coordination, and coherence among these actors and mechanisms, the author suggests that these ends may be achieved by placing an emphasis on plurality, complementarity, and mutual support through, inter alia, more effective policy oversight and enhanced inter-institutional relations.

Design of YCF-1 mobile γ irradiator

International Nuclear Information System (INIS)

Zhang Hehu; Wang Chuanzhen

1993-01-01

YCF-1 mobile irradiator has been designed by Beijing Institute of Nuclear Engineering of China and has been put into use in Jilin province. It can play an important role in extending irradiation technology in food irradiation, disinfestation, sterilization and quarantine. This paper describes the features and design considerations of a mobile irradiator. The irradiator uses a Cesium-137 source, the design loading capacity of the source is 9.25 PBq (250 kCi). The half-life of Cs-137 is 30.2 years and the source does not need replacing. The dose rate on the surface is 0.0025 mSv/h in accordance with national standards. The shielding of the irradiation room is a steel shell filled with lead. The thickness of lead is 18 cm. The irradiator is installed on a special flat truck. The weight of the irradiator is more than 80 tons. The main components and parts of the irradiator are: source, source racks and hoist, irradiation chamber, storage source chamber, the product's transport system, dose monitoring system, ventilation system and safety interlock system. (author)

Detection of Irradiated Korean Wheat Flour by Viscosity and Pulsed Photostimulated Luminescence (PPSL) Methods

International Nuclear Information System (INIS)

Yi, S.D.; Chang, K.S.; Oh, M.J.

2005-01-01

This study was carried out to establish methods for irradiation detection of irradiation in Korean wheat flour by pulsed photostimulated luminescence (PPSL) and viscometric methods. The photon counts of the irradiated Korean wheat flour measured by PPSL immediately after irradiation increased with increasing irradiation dose. The photon counts in the irradiated Korean wheat flour almost disappeared with lapse of time after storage in normal room conditions, but irradiation detection was still possible after 6 months in darkroom conditions

Room for climate debate : perspectives on the interaction between climate politics, science and the media

NARCIS (Netherlands)

van der Sluijs, J.P.; van Est, R.; Riphagen, M.

2010-01-01

The present study offers a picture of the complex interaction between climate politics, science and the media. During the 1970s and 1980s, politics and the sciences focused increasingly on the climate problem, at the time known as the greenhouse effect. Due to a lack of sufficient scientific

Degradation behaviour of fiber reinforced plastic under electron beam irradiation

International Nuclear Information System (INIS)

Sonoda, Katsumi; Yamamoto, Yasushi; Hashimoto, Osamu

1989-01-01

Various mechanical properties of four kinds of glass fiber-reinforced plastics irradiated with electron beams were examined at three temperatures; room temperature, 123 K and 77 K. Dynamic viscoelastic properties were measured, and fractography by means of scanning electron microscopy was observed in order to clarify degradation behaviour. A considerable decrease in interlaminar shear strength (ILSS) at room temperature was observed above 60 MGy. On the other hand, the three-point bending strength at 77 K and the ILSS at 123 K decreased with increasing irradiation. Fractography reveals that the degradation of the interface layer between matrix resin and fiber plays an important role in the strength reduction at 123 K and 77 K. These findings suggest that the interface between matrix resin and fiber loses its bondability at 123 K arid 77 K after electron beam irradiation. (author)

Temperature annealing of tracks induced by ion irradiation of graphite

International Nuclear Information System (INIS)

Liu, J.; Yao, H.J.; Sun, Y.M.; Duan, J.L.; Hou, M.D.; Mo, D.; Wang, Z.G.; Jin, Y.F.; Abe, H.; Li, Z.C.; Sekimura, N.

2006-01-01

Highly oriented pyrolytic graphite (HOPG) samples were irradiated by Xe ions of initial kinetic energy of 3 MeV/u. The irradiations were performed at temperatures of 500 and 800 K. Scanning tunneling microscopy (STM) images show that the tracks occasionally have elongated structures under high-temperature irradiation. The track creation yield at 800 K is by three orders of magnitude smaller compared to that obtained during room-temperature irradiation. STM and Raman spectra show that amorphization occurs in graphite samples irradiated at 500 K to higher fluences, but not at 800 K. The obtained experimental results clearly reveal that the irradiation under high temperature causes track annealing

Ozone production in a dielectric barrier discharge with ultrasonic irradiation

DEFF Research Database (Denmark)

Drews, Joanna Maria; Kusano, Yukihiro; Leipold, Frank

2011-01-01

Ozone production has been investigated using an atmospheric pressure dielectric barrier discharge in pure O2 at room temperature with and without ultrasonic irradiation. It was driven at a frequency of either 15 kHz or 40 kHz. The ozone production was highly dependent on the O2 flow rate and the ......Ozone production has been investigated using an atmospheric pressure dielectric barrier discharge in pure O2 at room temperature with and without ultrasonic irradiation. It was driven at a frequency of either 15 kHz or 40 kHz. The ozone production was highly dependent on the O2 flow rate...

Improvement of Microbiological and Sensory Quality of Fried Seasoning Anchovy Fish Snack by Gamma Irradiation

International Nuclear Information System (INIS)

Prakongsil, Panchalee; Neramitmansook, Naruemon; Phianphak, Wannipa; Kaewchoung, Pravait

2009-07-01

Full text: Microbiological and sensory qualities of gamma irradiated fried seasoning anchovy fish snack were evaluated. The samples were packed in polyethylene bags and stored under three different conditions. In Group I, the fish snacks were vacuum-packed and stored at room temperature. In Group II, the bags were sealed normally and stored at room temperature. Group-III samples were packed as in Group II but they were stored at 18 O C. Gamma irradiation was applied at the minimum absorbed dose of 2.0 kGy. Microbiological qualities were evaluated at 1, 2 and 3 months post irradiation. At three months, unirradiated samples from all three storage conditions were found with their total bacterial counts exceeding the limit for the quality standard of the Ministry of Industry (>10 3 cfu/g), while the total bacterial counts from irradiated samples were 1 log cycle fewer than those from unirradiated samples. The total yeast and mold counts produced by irradiated samples were within the limit throughout the three-month storage for all three conditions. E. coli, Salmonella spp., S. aureus and Clostridium spp. were not found under all storage conditions for both irradiated and unirradiated samples. No significant differences in the sensory quality were observed between irradiated and unirradiated samples for all three conditions. Although irradiated fried seasoning anchovy fish snack in a vacuum pack yielded better microbiological qualities than irradiated samples in a normal-sealed pack, samples in a normal-sealed pack stored at room temperature would be more appropriate for commercial production when production costs were considered

Cellulose gels produced in room temperature ionic liquids by ionizing radiation

International Nuclear Information System (INIS)

Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa

2014-01-01

Cellulose-based gels were produced in room temperature ionic liquids (RTILs) by ionizing radiation. Cellulose was dissolved at the initial concentration of 20 wt% in 1-ethyl-3-methylimidazolium (EMI)-acetate or N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEMA)-formate with a water content of 18 wt%, and irradiated with γ-rays under aerated condition to produce new cellulose gels. The gel fractions of the cellulose gels obtained in EMI-acetate and DEMA-formate at a dose of 10 kGy were 13% and 19%, respectively. The formation of gel fractions was found to depend on the initial concentration of cellulose, water content, and irradiation temperature. The obtained gel readily absorbed water, methanol, ethanol, dichloromethane, N,N-dimethylacetamide, and RTILs. - Highlights: • Cellulose gels were produced in room temperature ionic liquids (RTILs). • Water plays a crucial role in the cross-linking reaction. • Cellulose gels swollen with RTILs show good electronic conductivity (3.0 mS cm −1 )

Evaluation of time-accelerated irradiation method of elastomer by modulus-ultimate elongation profile

International Nuclear Information System (INIS)

Ito, Masayuki; Oka, Toshitaka; Hama, Yosimasa

2009-01-01

'Generalized modulus-ultimate elongation profile' was induced from the relationship between the modulus and the ultimate elongation of an elastomer that was quantitatively added crosslinking and scission. This profile can be used to evaluate the time-accelerated irradiation methods of ethylene-propylene-diene elastomer. The irradiation under low dose rate (0.33 kGy/h) at room temperature was the reference condition. The short-time irradiation condition was 4.2 kGy/h in 0.5 MPa oxygen at room temperature and 5.0 kGy/h in air at 70 o C. The former tended to bring about the higher ratio of scission than the reference condition; the latter tended to bring about the higher ratio of crosslinking.

Effect of milk temperature during irradiation on total bacterial count and keeping quality

International Nuclear Information System (INIS)

Sabbour, M.M.; Dawod, A.H.; Newigy, N.A.; Wahab, G.A.M.

1989-01-01

Cows' and buffaloes' milk samples were exposed to different doses of gamma radiation (100, 200 and 300 Kr) at 10 and 30°C. Irradiation of milk at 10°C caused more reduction in total bacterial count than that occurred at 30°C. The rate of microbial destruction due to irradiation at 10°C was higher than that occurred at 30°C. The keeping quality was determined daily for 15 days by clot-on-boiling test for samples kept at room temperature and in a refrigerator. The keeping quality recorded for cows' and buffaloes' milk samples in the refrigerator was 4 days, while it was only 1 day at room temperature. Irradiation of milk at 10°C was more effective than irradiation at 30°C, to increase the keeping quality of irradiated milk kept at refrigeration. Irradiation of milk samples at 10°C by 200 Kr increased the keeping quality for two weeks in the refrigerator, i.e. such a treatment increased the keeping quality by 4 folds

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

The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy under Xe26+ ion irradiation

Science.gov (United States)

Chen, Huaican; Hai, Yang; Liu, Renduo; Jiang, Li; Ye, Xiang-xi; Li, Jianjian; Xue, Wandong; Wang, Wanxia; Tang, Ming; Yan, Long; Yin, Wen; Zhou, Xingtai

2018-04-01

The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy was investigated. 7 MeV Xe26+ ion irradiation was performed at room temperature and 650 °C with peak damage dose from 0.05 to 10 dpa. With the increase of damage dose, the hardness of Ni-Mo-Cr and Ni-W-Cr alloy increases, and reaches saturation at damage dose ≥1 dpa. Moreover, the damage dose dependence of hardness in both alloys can be described by the Makin and Minter's equation, where the effective critical volume of obstacles can be used to represent irradiation hardening resistance of the alloys. Our results also show that Ni-W-Cr alloy has better irradiation hardening resistance than Ni-Mo-Cr alloy. This is ascribed to the fact that the W, instead of Mo in the alloy, can suppress the formation of defects under ion irradiation.

Radiation doses inside industrial irradiation installation with linear electron accelerator

International Nuclear Information System (INIS)

Lima, Alexandre R.; Pelegrineli, Samuel Q.; Alo, Gabriel F.; Silva, Francisco C.A. Da

2015-01-01

Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

Radiation doses inside industrial irradiation installation with linear electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Lima, Alexandre R., E-mail: alexandre.lima@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Pelegrineli, Samuel Q.; Alo, Gabriel F., E-mail: samuelfisica@yahoo.com.br, E-mail: gabriel.alo@aceletron.com.br [Aceletron Irradiacao Industrial, Aceletrica Comercio e Representacoes Ltda, Rio de Janeiro, RJ (Brazil); Silva, Francisco C.A. Da, E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Yu, H.; Yao, Z., E-mail: 12hy1@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada); Kirk, M.A. [Argonne National Laboratory, Materials Science Division, Argonne, IL (United States); Daymond, M.R. [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

2015-07-01

In situ heavy ion irradiation with 1 MeV Kr{sup 2+} was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 {sup o}C or 450 {sup o}C. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 {sup o}C irradiation but not at 450 {sup o}C. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2<111> and <001> both present in β-Zr under room temperature irradiation. (author)

Ferromagnetism in proton irradiated 4H-SiC single crystal

Directory of Open Access Journals (Sweden)

Ren-Wei Zhou

2015-04-01

Full Text Available Room-temperature ferromagnetism is observed in proton irradiated 4H-SiC single crystal. An initial increase in proton dose leads to pronounced ferromagnetism, accompanying with obvious increase in vacancy concentration. Further increase in irradiation dose lowers the saturation magnetization with the decrease in total vacancy defects due to the defects recombination. It is found that divacancies are the mainly defects in proton irradiated 4H-SiC and responsible for the observed ferromagnetism.

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

Room-temperature effects of UV radiation in KBr:Eu{sup 2+} crystals

Energy Technology Data Exchange (ETDEWEB)

Perez-Salas, R; Melendrez, R [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada - IFUNAM, Ensenada, Apartado Postal 2732 Ensenada, BC, 22800 (Mexico); Aceves, R; Rodriguez, R; Barboza-Flores, M [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088 Hermosillo, Sonora, 83190 (Mexico)

1996-07-01

Thermoluminescence and optical absorption measurements have been carried out in KBr:Eu{sup 2+} crystals irradiated with monochromatic UV light (200-300 nm) and x-rays at room temperature. For UV- and x-irradiated crystals strong similarities between the thermoluminescence glow curves have been found, suggesting that the low-energy UV radiation produces the same defects as produced by x-irradiation in this material. The thermoluminescence glow curves are composed of six glow peaks located at 337, 383, 403, 435, 475 and 509 K. Thermal annealing experiments in previously irradiated crystals show clearly a correlation between the glow peak located at 383 K and the F-centre thermal bleaching process. Also, the excitation spectrum for each thermoluminescence glow peak has been investigated, showing that the low-energy radiation induces the formation of F centres. (author)

Gamma irradiation effects on poly(vinylidene fluoride) films

International Nuclear Information System (INIS)

Ribeiro, Geise; Zen, Heloisa A.; Geraldes, Adriana N.; Souza, Camila P.; Parra, Duclerc F.; Lima, Luis Filipe C.P.; Lugao, Ademar B.

2009-01-01

In this work, the properties of Poly(vinylidene fluoride) PVDF films after exposing to gamma radiation at different doses (5, 10 and 15 kGy) were investigated. PVDF is a semicrystalline polymer that shows good properties in terms of chemical, thermal and electrical stabilities. The gamma radiation is a convenient and effective way of modification perfluorinated and partially fluorinated polymers such as PVDF. The properties of the pristine and irradiated PVDF films were studied by infrared spectroscopy, thermal analysis (TGA and DSC) and mechanical measurements at room temperature and at melting temperature of the PVDF. The infrared spectra of the irradiated PVDF samples do not present significant alterations in the absorption bands at all irradiated doses. The results obtained by thermal analysis indicate that the radiation does not alter significantly the decomposition temperature of the pristine PVDF film. Tensile strength measurements at room temperature before and after exposition to gamma radiation showed decrease of elongation at rupture in relation of pristine PVDF, suggesting that the radiation caused the crosslinking or chain scission of the PVDF film. (author)

The World Climate Project: Bringing the UN Climate Negotiations to Classrooms, Boardrooms, and Living Rooms Near You

Science.gov (United States)

Rath, K.; Rooney-varga, J. N.; Jones, A.; Johnston, E.; Sterman, J.

2015-12-01

As a simulation-based role-playing exercise, World Climate provides an opportunity for participants to have an immersive experience in which they learn first-hand about both the social dynamics of climate change decision-making, through role-play, and the geophysical dynamics of the climate system, through an interactive computer simulation. In June 2015, we launched the World Climate Project with the intent of bringing this powerful tool to students, citizens, and decision-makers across government, NGO, and private sectors around the world. Within a period of six weeks from the launch date, 440 educators from 36 states and 56 countries have enrolled in the initiative, offering the potential to reach tens of thousands of participants around the world. While this project is clearly in its infancy, we see several characteristics that may be contributing to widespread interest in it. These factors include the ease-of-use, real-world relevance, and scientific rigor of the decision-support simulation, C-ROADS, that frames the World Climate Exercise. Other characteristics of World Climate include its potential to evoke an emotional response that is arousing and inspirational and its use of positive framing and a call to action. Similarly, the World Climate Project takes a collaborative approach, enabling educators to be innovators and valued contributors and regularly communicating with people who join the initiative through webinars, social media, and resources.

Effects of gamma-irradiation on meat proteins

International Nuclear Information System (INIS)

Yook, H.S.; Kim, M.R.; Kim, J.O.; Lim, S.I.; Byun, M.W.

1998-01-01

The proteins extracted from beef, pork and chicken meats were irradiated with up to 100 kGy at room temperature. The extracted proteins were evaluated on their in vitro digestibility by incubating successively with pepsin and pancreatin conjugate. Amino acid compositions and SDS-PAGE pattern were also analyzedin for these proteins. Gamma irradiation within the applied dose range (up to 100 kGy) produced negligible in in vitro digestibility and amino acid composition. Analysis of gamma-irradiated proteins by SDS-PAGE revealed radiolysis of ovalbumin to proteins or peptides with lower molecular weight. On the other hand, the proteins directly extracted from irradiated meats containing moisture were also evaluated for their in vitro digestibility, amino acid compositions and SDS-PAGE pattern. However, the results obtained from this experiment were similar to those of irradiated proteins after extraction from the meats

Influence of ultrasonic irradiation on ozone generation in a dielectric barrier discharge

DEFF Research Database (Denmark)

Kusano, Yukihiro; Drews, J.; Leipold, Frank

2012-01-01

An atmospheric pressure dielectric barrier discharge (DBD) was generated in an N2/O2 gas mixture at room temperature with and without ultrasonic irradiation to investigate ozone production. Powerful ultrasonic irradiation with the sound pressure level of approximately 150 dB into the DBD can...

Proton irradiation of a swept charge device at cryogenic temperature and the subsequent annealing

International Nuclear Information System (INIS)

Gow, J P D; Smith, P H; Hall, D J; Holland, A D; Murray, N J; Pool, P

2015-01-01

A number of studies have demonstrated that a room temperature proton irradiation may not be sufficient to provide an accurate estimation of the impact of the space radiation environment on detector performance. This is a result of the relationship between defect mobility and temperature, causing the performance to vary subject to the temperature history of the device from the point at which it was irradiated. Results measured using Charge Coupled Devices (CCD) irradiated at room temperature therefore tend to differ from those taken when the device was irradiated at a cryogenic temperature, more appropriate considering the operating conditions in space, impacting the prediction of in-flight performance. This paper describes the cryogenic irradiation, and subsequent annealing of an e2v technologies Swept Charge Device (SCD) CCD236 irradiated at −35.4°C with a 10 MeV equivalent proton fluence of 5.0 × 10 8 protons · cm −2 . The CCD236 is a large area (4.4 cm 2 ) X-ray detector that will be flown on-board the Chandrayaan-2 and Hard X-ray Modulation Telescope spacecraft, in the Chandrayaan-2 Large Area Soft X-ray Spectrometer and the Soft X-ray Detector respectively. The SCD is readout continually in order to benefit from intrinsic dither mode clocking, leading to suppression of the surface component of the dark current and allowing the detector to be operated at warmer temperatures than a conventional CCD. The SCD is therefore an excellent choice to test and demonstrate the variation in the impact of irradiation at cryogenic temperatures in comparison to a more typical room temperature irradiation

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

Changes of endogenous hormones in irradiated potato tubers

International Nuclear Information System (INIS)

Farag, S.E.A.; El-Saeid, H.M.; Abou-Hadid, A.F.

1992-01-01

Potato tubers Solatum tuberosum L. cv. Alpha were irradiated with 0.12 kgy and stored at room temperature. The endogenous hormones were extracted and determined using bioassay at dormant, budding and sprouting stages. The studied promoters were IAA, IAN, GA3 and Gibberellin like substances besides the inhibitors which included ABA and B-inhibitors. The results indicated that IAA was more sensitive to irradiation than IAN, GA3 but ABA was more stable than B-inhibitors during the dormancy. Irradiation decreased IAA and Gibberellin like substances and B-inhibitors but no change was observed in ABA content at dormant period. Irradiation caused a balance between promoters inhibitors at the end of tuber storage and after tubers sprouting

Market testing of irradiated food

International Nuclear Information System (INIS)

Duc, Ho Minh

2001-01-01

Viet Nam has emerged as one of the three top producers and exporters of rice in the world. Tropical climate and poor infrastructure of preservation and storage lead to huge losses of food grains, onions, dried fish and fishery products. Based on demonstration irradiation facility pilot scale studies and marketing of irradiated rice, onions, mushrooms and litchi were successfully undertaken in Viet Nam during 1992-1998. Irradiation technology is being used commercially in Viet Nam since 1991 for insect control of imported tobacco and mould control of national traditional medicinal herbs by both government and private sectors. About 30 tons of tobacco and 25 tons of herbs are irradiated annually. Hanoi Irradiation Centre has been continuing open house practices for visitors from school, universities and various different organizations and thus contributed in improved public education. Consumers were found to prefer irradiated rice, onions, litchi and mushrooms over those nonirradiated. (author)

Study on quality control of Chinese herb medicine irradiation

International Nuclear Information System (INIS)

Yang Dongqing; En Lihua; Deng Wenmin

2010-01-01

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

Bed-integrated local exhaust ventilation system combined with local air cleaning for improved IAQ in hospital patient rooms

DEFF Research Database (Denmark)

Bivolarova, Mariya Petrova; Melikov, Arsen Krikor; Mizutani, Chiyomi

2016-01-01

the exposure to body generated bio-effluents in a hospital room was determined. Full-scale experiments were conducted in a climate chamber furnished as a single-bed patient room. Two heated dummies were used to simulate a patient and a doctor in the room. The patient was lying on a bed equipped with the VM...

DETECTION OF SOME IRRADIATED NUTS BY ELECTRON SPIN RESONANCE (ESR) TECHNIQUE

Energy Technology Data Exchange (ETDEWEB)

KHALLAF, M F; YASIN, N M.N. [Food Science Dept., Faculty of Agriculture, Ain Shams University, Cairo (Egypt); EL-NASHABY, F M; ALI, H G.M.; EL-SHIEMY, S M [Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt)

2008-07-01

The present investigation was carried out to establish the electron spin resonance (ESR) detection method for identifying irradiated nuts (almond and pistachio). Samples were irradiated with 2, 4 and 6 kGy and stored at room temperature (25{+-} 2{sup 0}C) for six months to study the possibility of detecting its previous irradiation treatments by ESR spectroscopy. Analysis was carried out just after irradiation treatment and during ambient storage period. The ESR signal intensities of irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation so, all irradiated samples under investigation could be differentiated from non-irradiated ones immediately after irradiation treatment. The decay in radicals responsible of ESR signals showed the identification of irradiated almond (shell or edible part) and pistachio (edible part) was impossible after six months of ambient storage.

DETECTION OF SOME IRRADIATED NUTS BY ELECTRON SPIN RESONANCE (ESR) TECHNIQUE

International Nuclear Information System (INIS)

KHALLAF, M.F.; YASIN, N.M.N.; EL-NASHABY, F.M.; ALI, H.G.M.; EL-SHIEMY, S.M.

2008-01-01

The present investigation was carried out to establish the electron spin resonance (ESR) detection method for identifying irradiated nuts (almond and pistachio). Samples were irradiated with 2, 4 and 6 kGy and stored at room temperature (25± 2 0 C) for six months to study the possibility of detecting its previous irradiation treatments by ESR spectroscopy. Analysis was carried out just after irradiation treatment and during ambient storage period. The ESR signal intensities of irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation so, all irradiated samples under investigation could be differentiated from non-irradiated ones immediately after irradiation treatment. The decay in radicals responsible of ESR signals showed the identification of irradiated almond (shell or edible part) and pistachio (edible part) was impossible after six months of ambient storage

Solar Radiation and Climate Experiment (SORCE) Satellite

Science.gov (United States)

2003-01-01

This is a close-up of the NASA-sponsored Solar Radiation and Climate Experiment (SORCE) Satellite. The SORCE mission, launched aboard a Pegasus rocket January 25, 2003, will provide state of the art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. Critical to studies of the Sun and its effect on our Earth system and mankind, SORCE will provide measurements that specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. Orbiting around the Earth accumulating solar data, SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolo meters engineered into instruments mounted on a satellite observatory. SORCE is carrying 4 instruments: The Total Irradiance Monitor (TIM); the Solar Stellar Irradiance Comparison Experiment (SOLSTICE); the Spectral Irradiance Monitor (SIM); and the XUV Photometer System (XPS).

Climate Forcing Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Records of changes in solar irradiance, volcanic aerosols, atmospheric trace gases, and other properties thought to influence climate in the past. Parameter keywords...

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

Structural changes of polytetrafluoroethylene during irradiation in oxygen

International Nuclear Information System (INIS)

Liu, Shuling; Fu, Congli; Gu, Aiqun; Yu, Zili

2015-01-01

To study the effect of irradiation on PTFE structure and prepare modified PTFE micropowder, PTFE was irradiated with dose up to 4 MGy in oxygen at room temperature. The structures of both irradiated and unirradiated PTFE samples were comparatively characterized by IR, XPS, Raman spectra and XRD measurement. The results showed that new groups of acyl fluoride (COF), carboxylic acid (COOH) and trifluoromethyl (CF 3 ) were formed under heavy radiation exposure in oxygen. In addition, the expansion of crystallite size or crystal lattice was first reported for the irradiated PTFE. The formation of new chemical groups and the expansion of crystallite size were elucidated by structural changes occurring in irradiation. - Highlights: • The structural change of PTFE irradiated in O 2 is different from that in vacuum. • The double bond is not found in PTFE after irradiation in oxygen. • The new groups like COF, COOH and CF 3 are formed in PTFE after irradiation. • The expansion of crystallite size is observed in the irradiated PTFE

Magnetic, thermal and luminescence properties in room-temperature nanosecond electron-irradiated various metal oxide nanopowders

Science.gov (United States)

Sokovnin, S. Yu; Balezin, M. E.; Il’ves, V. G.

2018-03-01

By means of pulsed electron beam evaporation in vacuum of targets non-magnetic, in bulk state, Al2O3 and YSZ (ZrO2-8% Y2O3) oxides, magnetic nanopowders (NPs) with a high specific surface were produced. The NPs were subsequently irradiated in air by electrons with energy of 700 keV, using a URT-1 accelerator for 15 and 30 minutes. The magnetic, thermal, and pulsed cathodoluminescence (PCL) characteristics of NPs were measured before and after irradiation. It was established that the electron irradiation non-monotonically changes the magnetization of the pristine samples. To the contrary, a clear correlation between the intensity of PCL and the irradiation doses is found in the oxides. There was a decrease in the intensity of PCL after irradiation. Luminescent and thermal properties reflect the transformation of structural defects in NPs more strongly after the exposure to a pulsed electron beam in comparison with corresponding changes of the NPs magnetic response.

Application of irradiation techniques to food and foodstuffs

International Nuclear Information System (INIS)

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

1991-02-01

A preservation study of dried fish, anchovies, has been conducted to determine the effect of gamma irradiation and laminated(nylon/polyethylene) film packaging on microbiological, physicochemical and organoleptic qualities of stored samples under room, refrigeration and freezing temperatures. Irradiation at less than 5 kGy and NY/PE-laminated film packaging are anticipated to be significantly effective for over 10 months in terms of improving the hygienic quality and extending the storage life of boiled-dried anchovies. In a survey participating 700 consumers, respondents preferred irradiated food to chemically-treated one. However, majority of respondents (55.7 %) was ignorant of the fact that the Korean government and international organizations concerned have approved the wholesomeness of irradiated food. Insufficiency of public information and understanding for irradiated food was indicated as a major cause for retardation of commercial utilization of food irradiation technology. In a response concerning perception and acceptance toward irradiated food, there was a significant difference between radiation worker and the general public. (Author)

Absorbed dose to mice in prolonged irradiation by low-dose rate ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Shiragai, Akihiro [National Inst. of Radiological Sciences, Chiba (Japan); Saitou, Mikio; Kudo, Iwao [and others

2000-07-01

In this paper, the dose absorbed by mice was evaluated as a preliminary study of the late effects of prolonged continuous irradiation of mice with low-dose rate ionizing radiation. Eight-week-old male and female SPF C3H/HeN mice in three irradiation rooms were exposed to irradiation at 8000, 400, and 20 mGy, respectively, using a {sup 137}Cs {gamma}-source. Nine racks were arranged in a circle approximately 2.5 m from the source in each room, and 10 cages were arranged on the 4 shelves of each rack. Dose distributions, such as in air at the source level, in the three rooms were estimated by using ionization chambers, and the absorbed dose distributions in the room and relative dose distributions in the cages in relation to the distance of the cage center were examined. The mean abdomen doses of the mice measured by TLD were compared with the absorbed doses in the cages. The absorbed dose distributions showed not only inverse-inverse-square-law behavior with distance from the source, but geometric symmetry in every room. The inherent scattering and absorption in each room are responsible for such behavior and asymmetry. Comparison of relative dose distributions revealed cage positions that are not suitable for experiments with high precision doses, but all positions can be used for prolonged continuous irradiation experiments if the position of the cages is rotated regularly. The mean abdomen doses of the mice were similar in each cage. The mean abdomen doses of the mice and the absorbed doses in a cage were almost the same in all cages. Except for errors concerning the positions of the racks and cages, the uncertainties in the exposure doses were estimated to be about {+-}12% for 8000 mGy group, 17% for 400 mGy group, and 35% for 20 mGy group. (K.H.)

Modification of polycrystalline copper by proton irradiation

International Nuclear Information System (INIS)

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

1997-01-01

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

Accelerated color development of irradiated radiochromic dye films

International Nuclear Information System (INIS)

Chappas, W.J.

1981-01-01

The radiochromic dye films developed by Chalkley and McLaughlin are quickly becoming one of the principal methods for secondary dosimetry. Their useful dose and dose rate ranges, long-term color stability, small and flexible size, and ease of reading make them ideal for spatial dose distribution measurements in the complex targets often encountered in industry. At room temperature, however, their response is slow, requiring several hours after irradiation for full color development. This work examines the effect of humidity on the film's time response and describes a method for accelerating the film's color development. By keeping the film in a controlled humidity environment or through a simple heating technique, the film can be read in minutes instead of hours after irradiation. The results are shown to be identical to those of films stored for 24 hours at room temperature

Effect of gamma irradiation on storability of Syrian walnut

Energy Technology Data Exchange (ETDEWEB)

Al-Bachir, M [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Radiation Technology

2001-12-01

Walnut fruits of Baladi variety were irradiated with 0, 0.5, 1.0, 1.5 and 2.0 kGy of gamma irradiation. The irradiated and unirradiated fruits were stored at room temperature (15 to 18 Centigrade) and at a relative humidity of 50 to 70%. Fungal load, proximate composition, chemical changes and sensory properties of nuts were evaluated immediately after irradiation, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the fungal load. Used doses did not cause any significant change in proximate composition of walnuts. Immediately after irradiation, gamma irradiation increased total acidity and decreased iodine value and the volatile basic nitrogen (VBN). whereas, after 12 months of storage, gamma irradiation decreased total acidity and peroxide value and increased iodine value and (VBN). Immediately after irradiation no significant differences were observed between irradiated and non-irradiated samples in flavor and aroma. Whereas, after 12 months of storage higher doses (1.5 and 2.0 kGy) had a negative effect on sensory characteristics. (author)

Effect of gamma irradiation on storability of Syrian walnut

International Nuclear Information System (INIS)

Al-Bachir, M.

2002-01-01

Walnut fruits of Baladi variety were irradiated with 0, 0.5, 1.0, 1.5 and 2.0 kGy of gamma irradiation. The irradiated and unirradiated fruits were stored at room temperature (15 to 18 Centigrade) and at a relative humidity of 50 to 70%. Fungal load, proximate composition, chemical changes and sensory properties of nuts were evaluated immediately after irradiation, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the fungal load. Used doses did not cause any significant change in proximate composition of walnuts. Immediately after irradiation, gamma irradiation increased total acidity and decreased iodine value and the volatile basic nitrogen (VBN). whereas, after 12 months of storage, gamma irradiation decreased total acidity and peroxide value and increased iodine value and (VBN). Immediately after irradiation no significant differences were observed between irradiated and non-irradiated samples in flavor and aroma. Whereas, after 12 months of storage higher doses (1.5 and 2.0 kGy) had a negative effect on sensory characteristics. (author)

Investigation of microstructure and mechanical properties of proton irradiated Zircaloy 2

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Apu, E-mail: asarkar@barc.gov.in [Mechanical Metallurgy Division, Bhabha Atomic Reserch Centre, Mumbai, 400 085 (India); Kumar, Ajay [Nuclear Physics Division, Bhabha Atomic Reserch Centre, Mumbai, 400 085 (India); Mukherjee, S.; Sharma, S.K.; Dutta, D.; Pujari, P.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Agarwal, A.; Gupta, S.K.; Singh, P. [Ion Accelerator Development Division, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Chakravartty, J.K. [Mechanical Metallurgy Division, Bhabha Atomic Reserch Centre, Mumbai, 400 085 (India)

2016-10-15

Samples of Zircaloy 2 have been irradiated with 4 MeV protons to two different doses. Microstructures of the unirradiated and irradiated samples have been characterized by Electron Back Scatter Diffraction (EBSD), X-ray diffraction line profile analysis (XRDLPA), Positron Annihilation Lifetime Spectroscopy (PALS) and Coincident Doppler Broadening (CDB) Spectroscopy. Tensile tests and micro hardness measurements have been carried out at room temperature to assess the changes in mechanical properties of Zircaloy 2 due to proton irradiation. The correlation of dislocation density, grain size and yield stress of the irradiated samples indicated that an increase in dislocation density due to irradiation is responsible for the change in mechanical behavior of irradiated Zircaloy.

Development of re-crystallized W-1.1%TiC with enhanced room-temperature ductility and radiation performance

International Nuclear Information System (INIS)

Kurishita, H.; Matsuo, S.; Arakawa, H.; Sakamoto, T.; Kobayashi, S.; Nakai, K.; Takida, T.; Kato, M.; Kawai, M.; Yoshida, N.

2010-01-01

Ultra-fine grained (UFG) W-TiC compacts fabricated by powder metallurgical methods utilizing mechanical alloying (MA) are very promising for use in irradiation environments. However, the assurance of room-temperature ductility and enhancement in surface resistances to low-energy hydrogen irradiation are unsettled issues. As an approach to solution to these, microstructural modification by hot plastic working has been applied to UFG W-TiC processed by MA in a purified Ar or H 2 atmosphere and hot isostatic pressing (HIP). Hot plastically worked compacts have been subjected to 3-point bend tests at room temperature and TEM microstructural examinations. It is found that the microstructural modification allows us to convert UFG W-1.1%TiC to compacts exhibiting a very high fracture strength and appreciable ductility at room temperature. The compacts of W-1.1%TiC/Ar (MA atmosphere: Ar) and W-1.1%TiC/H 2 (MA atmosphere: H 2 ) exhibit re-crystallized structures with approximately 0.5 and 1.5 μm in grain size, respectively. It is shown that the enhancement of fracture resistance by microstructural modifications is attributed to significant strengthening of weak grain boundaries in the re-crystallized state. As a result the modified compacts exhibit superior surface resistance to low-energy deuteron irradiation.

Irradiation of starches for industrial uses: Chemical and physical effects

International Nuclear Information System (INIS)

Gonzalez, Maria E.

1999-01-01

Corn and cassava starches have been irradiated with gamma doses from 10 to 180 kGy and pastes have been prepared by boiling the starches in water. The rheological properties of the pastes have been determined showing that the 10 kGy dose reduces sharply the viscosity of the aqueous pastes. The solubility of the irradiated starches has been also studied. The cassava starch irradiated with 180 kGy is soluble in boiling water and remains soluble at room temperature. After some considerations on the chemical effects of the irradiation it is concluded that the irradiation technique is suitable to replace the chemical treatment in many industrial applications of the starch. (author)

Damage structure of gallium arsenide irradiated in a high-voltage electron microscope

International Nuclear Information System (INIS)

Loretto, D.; Loretto, M.H.

1989-01-01

Semi-insulating undoped gallium arsenide has been irradiated in a high-voltage electron microscope between room temperature and about 500 0 C for doses of up to 5 x 10 22 electrons cm -2 at 1 MeV. Room-temperature irradiation produces small (less than 5 nm) damage clusters. As the temperature of the irradiation is increased, the size of these clusters increases, until at about 300 0 C a high density of dislocation loops can be resolved. The dislocation loops, 20 nm or less in diameter, which are produced at about 500 0 C have been analysed in a bright field using a two-beam inside-outside method which minimises the tilt necessary between micrographs. It is concluded that the loops are an interstitial perfect-edge type with a Burgers vector of (a/2) . (author)

Diffuse Ceiling Ventilation and the Influence of Room Height and Heat Load Distribution

DEFF Research Database (Denmark)

Nielsen, Peter Vilhelm; Vilsbøll, Rasmus W; Liu, Li

2015-01-01

Diffuse ceiling (inlet) ventilation is an air distribution system that supplies air from the entire ceiling surface, giving a low supply velocity. The flow pattern in the room is controlled by the heat sources. The system generates high mixing flow and the air velocities in the room are expected...... to be not much influenced by the flow rate to the room but dependent on the heat load. Previous studies have shown that diffuse ceiling ventilation has an ability to remove large heat loads without compromising the indoor climate. However, recent experiments indicate that the maximum accepted heat load decreases...... with a large room height and it decreases in connection with certain heat load distributions. Room geometries and heat load distributions that are optimal for diffuse ceiling ventilation are discussed. A simplified design procedure is introduced....

Viscometric and Pulsed Photostimulated Luminescence Properties of Irradiated Glutinous Rice

International Nuclear Information System (INIS)

Yang, J.S.; Yi, S.D.; Chang, K.S.; Oh, M.J.

2004-01-01

This study was carried out to establish a method for the detection of irradiated glutinous rice by measuring pulsed photostimulated luminescence (PPSL) and viscometric properties. Viscosity was determined using a Brookfield DV-III rotation viscometer at 3 deg. C and measured at 30, 60, 90, 120, 150, 180, and 210 rpm. All irradiated samples indicated a decrease in viscosity with increasing stirring speeds (rpm) and irradiation doses. Treatments with 2∼5 kGy significantly decreased the viscosity. The photon counts of the irradiated glutinous rice were measured by PPSL and the photon counts of the non-irradiated and irradiated glutinous rice measured immediately after irradiation exhibited an increase with increasing irradiation dose. The photon counts of irradiated glutinous rice almost disappeared with the lapse of time when stored under normal room conditions, but was still possible to detect after 12 months of darkroom storage. Consequently, these results indicate that the detection of irradiated glutinous rice is possible by both viscometric and PPSL methods

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)

Irradiation induced creep in whiskers of NaCl

International Nuclear Information System (INIS)

Khan, J.A.A.

1977-09-01

Whiskers of NaCl have been grown and irradiated under flexion by X-rays (approximately 2x10 7 R/h) at room temperature and the residual curvature measured. Complete recovery of the initial form of the whisker within an hour's annealing at 400 0 C proves clearly that the observed deformation (creep) is due to the presence of dislocation loops. The choice of NaCl extremely simplifies the experiment and its interpretation since X-rays create point defects one by one. Moreover, this mode of irradiation, at room temperature, produces a very simple situation: perfect interstitial dislocation loops and immobile point defects which are little influenced by the applied stress. The flexion leads to a stress system which hardly differs from an uniaxial stress. One can study separately the preferential nucleation of dislocation loops and their differential growth by carrying out an irradiation under stress followed by an irradiation without stress and vice versa. It is shown that the induced creep is mostly due to the preferential nucleation of dislocation loops and is little affected by the differential growth of these loops. The nucleation period of the loops is very short: a dose of approximately 10 -5 d.p.a. is largely sufficient for the quasi completion of dislocation loops in a crystal having an impurity concentration of approximately 10 -3 [fr

Influence of neutron irradiation on ferromagnetic metallic glasses

International Nuclear Information System (INIS)

Miglierini, M.; Nasu, Saburo; Sitek, J.

1992-01-01

Transmission 57 Fe Moessbauer spectroscopy is used to study effects of neutron irradiation on magnetic properties of Fe-based ferromagnetic metallic glasses. Elastic stress centers are produced during the process of neutron irradiation as a result of atom mixing. Rearrangement of the atoms causes changes in the average value of the hyperfine field distribution and orientation of the net magnetic moment. They are shown to depend on the composition of the investigated samples. Cr-doped metallic glasses depict transformation from ferromagnetic to paramagnetic state at room temperature after neutron irradiation implying changes in the Curie temperature. Presence of Ni in the samples reduces the effects of radiation damage. (orig.)

Ferrobielastic twinning in irradiated quartz

International Nuclear Information System (INIS)

Shiau, S.M.

1986-01-01

Cultured quartz is usually free from electrical twinning; however, it may occur if the seed crystal is twinned or if undue applied forces are exerted on the crystal. Ferrobielastic twinning was studied optically (photoelastic effect) and electrically (piezoelectric effect). At room temperature, twins were perceptible at stresses of about 2.l5 x 10 8 N/m 2 , and crystals switched from their original states to the alternative twin states at stresses about 5.0 x 10 8 N/m 2 (called coercive stress). The decrease in coercive stress with increasing temperature was observed, and these coercive stresses become very low as temperatures reach to 300 0 C. The effects of irradiation on the twinning in quartz were also studied. The presence of defects produced by irradiation was utilized to pin the domain wall motion. Both neutrons and gamma rays were employed. The stress required to nucleate an appreciable volume of twins is about twice as high for irradiated crystals than for those unirradiated. This result demonstrated that the irradiated crystals can tolerate higher stresses. However, the coercive stress for complete switch-over was not much different for irradiated and unirradiated crystals. It appears that the defects caused by irradiation eliminate the initial twinning events but do not affect switch-over

Effect of gamma irradiation on HPMC/ZnO nanocomposite films

International Nuclear Information System (INIS)

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

2015-01-01

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

Tracking with heavily irradiated silicon detectors operated at cryogenic temperatures

International Nuclear Information System (INIS)

Casagrande, L.; Barnett, B.M.; Bartalina, P.

1999-01-01

In this work, the authors show that a heavily irradiated double-sided silicon microstrip detector recovers its performance when operated at cryogenic temperatures. A DELPHI microstrip detector, irradiated to a fluence of ∼4 x 10 14 p/cm 2 , no longer operational at room temperature, cannot be distinguished from a non-irradiated one when operated at T < 120 K. Besides confirming the previously observed Lazarus effect in single diodes, these results establish, for the first time, the possibility of using standard silicon detectors for tracking applications in extremely demanding radiation environments

ESR identification of gamma-irradiated albendazole

Science.gov (United States)

Çolak, Seyda

2010-01-01

The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

Drop and recovery of thermal conductivity of AlN upon UV irradiation

International Nuclear Information System (INIS)

AlShaikhi, A; Srivastava, G P

2007-01-01

We have performed calculations of the room-temperature thermal conductivity of oxygen contaminated aluminium nitride (AlN) by employing the Callaway model with a detailed account of three-phonon scattering processes. The role of Al vacancy and O substitution of N has been examined in the form of extended defects (clusters) and point defects. Our work provides support for the theoretical model proposed by Harris et al. [Phys. Rev. B. 47, 5428 (1993)] to explain the experimentally observed drop in the conductivity upon UV irradiation and its recovery upon UV removal and subsequent illumination of the sample with visible light at room temperature. With the reported oxygen concentration in the sample, the scattering of phonons from oxygen-related extended defects is found to be ineffective. Within the picture presented by Harris et al., the point impurity scattering parameter increases by around 17% upon UV irradiation of the sample at room temperature

Middle atmosphere response to different descriptions of the 11-yr solar cycle in spectral irradiance in a chemistry-climate model

Directory of Open Access Journals (Sweden)

W. H. Swartz

2012-07-01

Full Text Available The 11-yr solar cycle in solar spectral irradiance (SSI inferred from measurements by the SOlar Radiation & Climate Experiment (SORCE suggests a much larger variation in the ultraviolet than previously accepted. We present middle atmosphere ozone and temperature responses to the solar cycles in SORCE SSI and the ubiquitous Naval Research Laboratory (NRL SSI reconstruction using the Goddard Earth Observing System chemistry-climate model (GEOSCCM. The results are largely consistent with other recent modeling studies. The modeled ozone response is positive throughout the stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with respect to total solar irradiance above 45 km. The modeled responses in total ozone are similar to those derived from satellite and ground-based measurements, 3–6 Dobson Units per 100 units of 10.7-cm radio flux (F_10.7 in the tropics. The peak zonal mean tropical temperature response using the SORCE SSI is nearly 2 K per 100 units F_10.7 – 3 times larger than the simulation using the NRL SSI. The GEOSCCM and the Goddard Space Flight Center (GSFC 2-D coupled model are used to examine how the SSI solar cycle affects the atmosphere through direct solar heating and photolysis processes individually. Middle atmosphere ozone is affected almost entirely through photolysis, whereas the solar cycle in temperature is caused both through direct heating and photolysis feedbacks, processes that are mostly linearly separable. This is important in that it means that chemistry-transport models should simulate the solar cycle in ozone well, while general circulation models without coupled chemistry will underestimate the temperature response to the solar cycle significantly in the middle atmosphere. Further, the net ozone response results from the balance of ozone production at wavelengths less than 242 nm

Technological quality of irradiated Moroccan citrus fruits

International Nuclear Information System (INIS)

Moussaid El Idrissi, M.; R'Kiek, C.; Farahat Laaroussi, S.; Zantar; Mouhib, M.; El Guerrouj, D.; Toukour, L.

2002-01-01

The effect of irradiation at doses of 125, 250, 375, and 500 Gy, commonly used for quarantine treatment, on the quality of Maroc-late orange, the most common export variety of Morocco was investigated. In the first study fruits were irradiated without any previous cold conditioning treatment as practiced by the export trade for quarantine purposes. In the second study fruits obtained from the normal chain after conditioning was irradiated. Storage of irradiated fruits was studied at room temperature and 10 deg. C at 0 deg. C in case of control fruits. The parameters studied included juice yield, total solids, reducing and total sugars, total acids and volatile acids, dry weight and weight loss. The results showed that irradiation did not affect the technological quality of citrus fruits during four weeks storage. The result thus far points to the possibility for the successful application of irradiation as an alternative quarantine treatment to the classical methods, which result in browning of the peel. The browning phenomenon could be controlled by waxing and will be the subject of a future study. (author)

Preliminary investigation on the extension of shelf-life of boiled Chub mackerel by irradiation

Energy Technology Data Exchange (ETDEWEB)

Loaharanu, P; Prombubesara, C; Songprasertchai, S

1971-12-31

The influence of irradiation on the extension of shelf-life of boiled Chub mackerel stored at room temperature (25-30{sup 0}C) was investigated. It was found that boiled Chub mackerel irradiated at 0.1, 0.2, or 0.3 Mrad could be kept with good organoleptic properties at room temperature for 5, 8, and 11 days respectively; while the unirradiated sample could be kept for only 2 days. Boiled Chub mackerel used in this study was found to be heavily contaminated with microorganisms. Irradiation at doses mentioned caused reduction of more than 99% of bacteria. Bacillus and Acinetobacter were found to predominate in the irradiated boiled mackerel. The predominant flora in unirradiated boiled mackerel included Micrococcus, Staphylococcus, Bacillus, Acinetobacter, and Proteus. E. coli was always detected in unirradiated samples and was occasionally detected only in samples irradiated at 0.1 Mrad. Trimethylamine nitrogen (TMA-N) content, total volatile basic nitrogen (TVB-N) content, and total bacterial count (TBC) were used as indices of decomposition of both irradiated and unirradiated samples. TMA-N and TBC were found to be good indices of quality of only unirradiated boiled Chub mackerel, whereas TVB-N was found to be a good index of quality of both irradiated and unirradiated samples.

utilization of some physical methods for detection of some irradiated foods

International Nuclear Information System (INIS)

Mohammed, I.A.S

2007-01-01

the present investigation was carried out to establish a detection method for irradiated black pepper and marjoram using thermoluminescence (TL) and wheat, cinnamon and ginger using viscosity measurement. all samples were packed in polyethylene bags then irradiated at 5,10 and 15 kGy for black pepper, marjoram, cinnamon and ginger. wheat was irradiated at 1,2 and 3 kGy. all samples were stored for eight months at room temperature. results indicated that irradiation treatment caused markedly increasing in TL intensity for irradiated black pepper and marjoram while irradiation treatment decreased apparent viscosity of wheat flour, cinnamon and ginger powder, post irradiation and during storage. therefore, it could be concluded that the TL analysis can be used to detect irradiated black pepper and marjoram, also viscosity measurement can be used to detect irradiate wheat flour, cinnamon and ginger powder than non-irradiated ones after irradiation process and also during 8 months of storage at ambient temperature

The influence of electron irradiation at the various temperatures and annealing on carriers mobility at the low temperatures in neutron transmutation doped gallium arsenide

International Nuclear Information System (INIS)

Korshunov, F.P.; Kurilovich, N.F.; Prokhorenko, T.A.; Troshchinskii, V.T.; Shesholko, V.K.

1999-01-01

The influence of electron irradiation at the various temperatures and annealing on measured at T=100 K carriers mobility in neutron transmutation doped GaAs have been investigated. It was detected that rate of mobility decreasing with irradiation dose increasing decreases when irradiation temperature increases. It was shown that at the same time it take place the radiation defects creating and their particular or full annealing (in the dependence on irradiation temperature). Radiation stimulated annealing (annealing that take place during irradiation at the elevated temperatures) is more effective than the annealing at the same temperatures that take place after crystals are irradiated at room temperature. It means that any defects annealing during irradiation at elevated temperatures take place at more low temperatures than that during annealing after irradiation at room temperature

Pollen and spores as biological recorders of past ultraviolet irradiance

NARCIS (Netherlands)

Jardine, P.E.; Fraser, W.T.; Lomax, B.H.; Sephton, M.A.; Shanahan, T.M.; Miller, C.S.; Gosling, W.D.

2016-01-01

Solar ultraviolet (UV) irradiance is a key driver of climatic and biotic change. Ultraviolet irradiance modulates stratospheric warming and ozone production, and influences the biosphere from ecosystem-level processes through to the largest scale patterns of diversification and extinction. Yet our

Analysis of the spatial dose according to the type of radiation source used in multi-bed hospital room

Energy Technology Data Exchange (ETDEWEB)

Jang, Dong Gun [Dept. of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences Cancer center, Busan (Korea, Republic of); Kim, Jung Hoon [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of); Park, Eun Tae [Dept. of Radiation Oncology, Busan Paik Hospital, Inje University, Busan (Korea, Republic of)

2017-09-15

Medical radiation offers significant benefits in diagnosing and treating patients, but it also generates unnecessary radiation exposure to those nearby. Accordingly, the objective of the present study was to analyze spatial dose rate according to types of radiation source term in multi-bed hospital rooms occupied by patients and general public. MCNPX was used for geometric simulation of multi-bed hospital rooms and radiation source terms, while the radiation source terms were established as whole body bone scan patients and imaging using a portable X-ray generator. The results of simulation on whole body bone scan patients showed 3.46 μSv/hr to another patient position, while experimental results on imaging using a portable X-ray generator showed 1.47 × 10{sup -8} μSv/irradiation to another patient position in chest imaging and 2.97 × 10{sup -8} μSv/irradiation to another patient position in abdomen imaging. Multi-bed hospital room, unnecessary radiation generated in the surrounding patients, while legal regulations and systematic measures are needed for radiation exposure in multi-bed hospital rooms that are currently lacking in Korea.

Annealing effects of carbon fiber-reinforced epoxy resin composites irradiated by electron beams

International Nuclear Information System (INIS)

Udagawa, Akira; Sasuga, Tuneo; Ito, Hiroshi; Hagiwara, Miyuki

1987-01-01

Carbon cloth-reinforced epoxy resin composites were irradiated with 2 MeV electrons at room temperature and then annealed in air for 2 h at temperatures up to 180 deg C. A considerable decrease in the three-point bending strength occurred when the irradiated composites were annealed in the temperature range of 115 - 135 deg C which is below the glass transition temperature T g of the matrix resin, while the bending strength remained unchanged up to 180 deg C for the unirradiated composites. In the dynamic viscoelastic spectra of the irradiated matrix, a new relaxation appeared at the temperature extending from 50 deg C to just below the matrix T g and disappeared on annealing for 2 h at 135 deg C. Annealing also decreased the concentration of free radicals existing stably in the irradiated matrix at room temperature. After annealing, a large amount of clacks and voids were observed in the fractography of the composites by scanning electron microscopy. These results indicate: (1) Annealing brings about rearrangement of the radiation-induced molecular chain scission in the matrix; (2) The bending strength of the irradiated composites decreased owing to the increased brittleness of the matrix by annealing. (author)

Positron annihilation lifetime measurements of vanadium alloy and F82H irradiated with fission and fusion neutrons

International Nuclear Information System (INIS)

Sato, K.; Inoue, K.; Yoshiie, T.; Xu, Q.; Wakai, E.; Kutsukake, C.; Ochiai, K.

2009-01-01

V-4Cr-4Ti, F82H, Ni and Cu were irradiated with fission and fusion neutrons at room temperature and 473 K. Defect structures were analyzed and compared using positron annihilation lifetime measurement, and microstructural evolution was discussed. The mean lifetime of positrons (the total amount of residual defects) increased with the irradiation dose. The effect of cascade impact was detected in Ni at room temperature. The size and the number of vacancy clusters were not affected by the displacement rate in the fission neutron irradiation at 473 K for the metals studied. The vacancy clusters were not formed in V-4Cr-4Ti irradiated at 473 K in the range of 10 -6 -10 -3 dpa. In F82H irradiated at 473 K, the defect evolution was prevented by pre-existing defects. The mean lifetime of positrons in fission neutron irradiation was longer than that in fusion neutron irradiation in V-4Cr-4Ti at 473 K. It was interpreted that more closely situated subcascades were formed in the fusion neutron irradiation and subcascades interacted with each other, and consequently the vacancy clusters did not grow larger.

An Analysis of Radiation Penetration through the U-Shaped Cast Concrete Joints of Concrete Shielding in the Multipurpose Gamma Irradiator of BATAN

Science.gov (United States)

Ardiyati, Tanti; Rozali, Bang; Kasmudin

2018-02-01

An analysis of radiation penetration through the U-shaped joints of cast concrete shielding in BATAN’s multipurpose gamma irradiator has been carried out. The analysis has been performed by calculating the radiation penetration through the U-shaped joints of the concrete shielding using MCNP computer code. The U-shaped joints were a new design in massive concrete construction in Indonesia and, in its actual application, it is joined by a bonding agent. In the MCNP simulation model, eight detectors were located close to the observed irradiation room walls of the concrete shielding. The simulation results indicated that the radiation levels outside the concrete shielding was less than the permissible limit of 2.5 μSv/h so that the workers could safely access electrical room, control room, water treatment facility and outside irradiation room. The radiation penetration decreased as the density of material increased.

High-energy electron beam irradiation of Al-doped ZnO thin films deposited at room temperature

International Nuclear Information System (INIS)

Yun, Eui-Jung; Jung, Jin-Woo; Hwang, Jong-Ha; Lee, Byung-Cheol; Jung, Myung-Hee

2011-01-01

In this research, we demonstrated the effects of high-energy electron beam irradiation (HEEBI) on the optical and structural properties of Al-doped ZnO (AZO) films grown on transparent corning glass substrates at room temperature (RT) by using a radio-frequency magnetron sputtering technique. The AZO thin films were treated with HEEBI in air at RT at an electron beam energy of 0.8 MeV and doses of 1 x 10 14 - 1 x 10 16 electrons/cm 2 . The photoluminescence (PL) measurements revealed that the dominant peak at 2.77 eV was a blue emission originating from donor-like defects, oxygen vacancies (V o ), suggesting that the n-type conductivity was preserved in HEEBI-treated films. On the basis of PL, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy results, we suggest that the density of V o donor defects is decreased due to in-diffusion of oxygen from the ambient into the films after HEEBI treatment at low doses up to 10 15 electrons/cm 2 while the opposite phenomenon can occur with further increase in the dose. We also found from the XRD analysis that the worse crystallinity with a smaller grain size was observed in HEEBI-treated AZO films at a higher dose, corresponding to a higher oxygen fraction in the films. We believe that our results will contribute to developing high-quality AZO-based materials and devices for space applications.

Use Of Ultra Violet Light (UV-C) To Reduce Possible Microbial Potential In Cold Storage Rooms Loaded With Sweet Potatoes For Exportation

International Nuclear Information System (INIS)

Yassin, Sh.M.; El-Neshawy, S.M.; Aly, A.Z.; Abdel Kader, D.A.

2012-01-01

Irradiation with Ultraviolet-c (UV-C) light (254 nm) was applied on sweet potatoes (cv. Abees) as well as the major recovered organisms that are accounted as contaminants in either the internal atmosphere or on sweet potato tuber roots loaded in cold storage room set at 17 degree C and 65-70% RH for 3 months. The captured types of microorganisms from either the internal atmosphere of cold storage room or surfaces of sweet potato tuber roots were fungi, yeast and bacteria with the greatest percentage of fungi that recorded 90% and 70%, respectively. The major individuals of recovered fungi were Penicillium spp., Alternaria alternata, Rhizopus stolonifer, Aspergillus spp., Botrytis cinerea, and Fusarium sp. in descending order of their existence percentages. Upon exposure, the internal atmosphere to UV-C light for one, two and three hours inside cold storage room, a significant reduction of the total number of different types of organisms was obtained with the greatest effect for the three hour-exposure time. Exposure of sweet potatoes to UV-C light at three exposure times (1, 2 and 3 hr) and stored in cold rooms for one month caused a reduction of rot percentages upon natural infection conditions with a full reduction (0 %) when irradiated for 3 hr at the same conditions. Rot percentages were decreased as the exposure time increased. Fruit characteristics in terms of tuber root firmness, shrinking and blemishing of irradiated tuber roots were remarkably maintained than which of the non irradiated ones. UV-C light caused a significant increase in phenol contents in tuber root tissue, while a reverse effect in sugar content was detected; such effects were correlated increasingly or decreasingly with the increase of exposure time. The activity of peroxidase, polyphenoloxidase or poly phenylalanine ammonia lyase (PAL) enzymes in irradiated tuber root tissues were significantly enhanced as the exposure time increased

Neutron irradiation effects on the mechanical properties of organic composite materials

International Nuclear Information System (INIS)

Egusa, S.; Kirk, M.A.; Birtcher, R.C.

1984-01-01

Neutron irradiations with low γ-ray flux in the Intense Pulsed Neutron Source were carried out on four kinds of cloth-filled organic composites (filler: E-glass or carbon fiber; matrix: epoxy or polyimide resin) and a unidirectional alumina fiber/epoxy composite. These composites were examined with regard to the mechanical properties at room temperature. Following irradiation at room temperature, the Young's (tensile) modulus of these composites remains practically unchanged up to a total neutron fluence of 5.0x10 18 n/cm 2 (1.4x10 18 n/cm 2 for E>0.1 MeV). The shear modulus and the ultimate strength, on the other hand, decrease significantly at this neutron fluence for the glass/epoxy and glass/polyimide composites, whereas for the other composites both properties do not degrade. This result is most likely ascribed to the radiation damage at fiber/matrix interface due to recoil particles produced by a 10 B(n,α) 7 Li reaction in the boron-containing E-glass fibers. Only for the E-glass fiber composites, in fact, the fracture propagation energy is appreciably increased by irradiation, while for the other composites the propagation energy is scarcely changed, thus confirming the significant contribution due to the 10 B reaction. As to the 5 K irradiation, degradation of the present composites was not observed up to a total neutron fluence of 1.0x10 18 n/cm 2 (7.0x10 17 n/cm 2 for E>0.1 MeV) when tested at room temperature. (orig.)

The improvement of corn starch isolation process by gamma irradiation

International Nuclear Information System (INIS)

Byun, M.W.; Kang, I.J.; Kwon, J.H.; Lee, S.J.; Kim, S.K.

1995-01-01

Gamma irradiation was applied to non-glutinous and glutinous corns for improving starch isolation process. No significant changes in proximate composition of corn grains were observed by gamma irradiation. Irradiation at 1 and 5 kGy was effective for sterilizing all contaminated microorganisms of non-glutinous and glutinous corns, respectively. The moisture-uptake rate constants were increased in proportional to the steeping temperature and applied irradiation dose level. The irradiation efficacy on water absorption properties was also recognized in the corns stored for six months at room temperature. The combined use of gamma irradiation with sulfur dioxide solution was very effective for reducing steeping time. The starch yield gradually increased as irradiation dose levels increased. At 2 kGy, the sarch yield of non-glutinous and glutinous corns increased by 38% and 27%, respectively. No significant difference in Hunter's color value was observed between the starches isolated from nonirradiated and irradiated corn grains

Corrosion characteristics of Hastelloy N alloy after He+ ion irradiation

International Nuclear Information System (INIS)

Lin Jianbo; Yu Xiaohan; Li Aiguo; He Shangming; Cao Xingzhong; Wang Baoyi; Li Zhuoxin

2014-01-01

With the goal of understanding the invalidation problem of irradiated Hastelloy N alloy under the condition of intense irradiation and severe corrosion, the corrosion behavior of the alloy after He + ion irradiation was investigated in molten fluoride salt at 700 °C for 500 h. The virgin samples were irradiated by 4.5 MeV He + ions at room temperature. First, the virgin and irradiated samples were studied using positron annihilation lifetime spectroscopy (PALS) to analyze the influence of irradiation dose on the vacancies. The PALS results showed that He + ion irradiation changed the size and concentration of the vacancies which seriously affected the corrosion resistance of the alloy. Second, the corroded samples were analyzed using synchrotron radiation micro-focused X-ray fluorescence, which indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Results from weight-loss measurement showed that the corrosion generally correlated with the irradiation dose of the alloy. (author)

E. s. r. of free radicals in irradiated uracil-. beta. -D-arabinofuranoside

Energy Technology Data Exchange (ETDEWEB)

Bergene, R [Oslo Univ. (Norway). Fysisk Institutt; Vaughan, R A

1976-02-01

Electron-spin-resonance measurements have been made on single crystals of uracil-..beta..-D-arabinofuranoside, which were irradiated by 4.0 MeV electrons at 77 K. At low temperatures, two radicals have been identified, one attributed to a hydrogen abstraction of 05' in the sugar moiety and the other to a radical anion located on the pyrimidine ring. The former was very unstable and seemed to act as a precursor to other unidentified radical species stable at 77 K. At room temperature, the main resonance was due to hydrogen addition to C5 and was probably produced by protonation of the anion. This same radical was also produced by irradiation at room temperature.

Influence of electron irradiation on the structural and thermal properties of silk fibroin films

Energy Technology Data Exchange (ETDEWEB)

Asha, S.; Sangappa,; Sanjeev, Ganesh, E-mail: ganeshanjeev@rediffmail.com [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore - 574 199 (India)

2015-06-24

Radiation-induced changes in Bombyx mori silk fibroin (SF) films under electron irradiation were investigated and correlated with dose. SF films were irradiated in air at room temperature using 8 MeV electron beam in the range 0-150 kGy. Various properties of the irradiated SF films were studied using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Electron irradiation was found to induce changes in the physical and thermal properties, depending on the radiation dose.

Development of re-crystallized W-1.1%TiC with enhanced room-temperature ductility and radiation performance

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H., E-mail: kurishi@imr.tohoku.ac.j [International Research Center for Nuclear Materials Science, IMR, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Matsuo, S.; Arakawa, H. [International Research Center for Nuclear Materials Science, IMR, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Sakamoto, T.; Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime University, Matsuyama 790-8577 (Japan); Takida, T.; Kato, M. [A.L.M.T. Corp., Toyama 931-8543 (Japan); Kawai, M. [Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Yoshida, N. [Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2010-03-15

Ultra-fine grained (UFG) W-TiC compacts fabricated by powder metallurgical methods utilizing mechanical alloying (MA) are very promising for use in irradiation environments. However, the assurance of room-temperature ductility and enhancement in surface resistances to low-energy hydrogen irradiation are unsettled issues. As an approach to solution to these, microstructural modification by hot plastic working has been applied to UFG W-TiC processed by MA in a purified Ar or H{sub 2} atmosphere and hot isostatic pressing (HIP). Hot plastically worked compacts have been subjected to 3-point bend tests at room temperature and TEM microstructural examinations. It is found that the microstructural modification allows us to convert UFG W-1.1%TiC to compacts exhibiting a very high fracture strength and appreciable ductility at room temperature. The compacts of W-1.1%TiC/Ar (MA atmosphere: Ar) and W-1.1%TiC/H{sub 2} (MA atmosphere: H{sub 2}) exhibit re-crystallized structures with approximately 0.5 and 1.5 mum in grain size, respectively. It is shown that the enhancement of fracture resistance by microstructural modifications is attributed to significant strengthening of weak grain boundaries in the re-crystallized state. As a result the modified compacts exhibit superior surface resistance to low-energy deuteron irradiation.

Direct or indirect UV-Irradiation in insect killers and similar equipment

International Nuclear Information System (INIS)

Heinz, G.

1978-01-01

UV sterilisation equipment is used in the refrigerating and storage rooms of food and meat processing factories. The UV radiation used has a wavelength of 254 nm. Due to possible side effects on the food, the packing is directly irradiated but the food itself only indirectly. This method makes high irradiation energies necessary for the inhibition of bacterial growth on the foodstuffs. (AJ) 891 AJ [de

Electrical properties of irradiated PVA film by using ion/electron beam

Science.gov (United States)

Abdelrahman, M. M.; Osman, M.; Hashhash, A.

2016-02-01

Ion/electron beam bombardment has shown great potential for improving the surface properties of polymers. Low-energy charged (ion/electron) beam irradiation of polymers is a good technique to modify properties such as electrical conductivity, structural behavior, and their mechanical properties. This paper reports on the effect of nitrogen and electron beam irradiation on the electrical properties of polyvinyl alcohol (PVA) films. PVA films of 4 mm were exposed to a charged (ion/electron) beam for different treatment times (15, 30, and 60 minutes); the beam was produced from a dual beam source using nitrogen gas with the other ion/electron source parameters optimized. The dielectric loss tangent tan δ , electrical conductivity σ , and dielectric constant ɛ ^' } in the frequency range 100 Hz-100 kHz were measured at room temperature. The variation of dielectric constant and loss tangent as a function of frequency was also studied at room temperature. The dielectric constant was found to be strongly dependent on frequency for both ion and electron beam irradiation doses. The real (ɛ ^' }) and imaginary (ɛ ^' ' }) parts of the dielectric constant decreased with frequency for all irradiated and non-irradiated samples. The AC conductivity showed an increase with frequency for all samples under the influence of both ion and electron irradiation for different times. Photoluminescence (PL) spectral changes were also studied. The formation of clusters and defects (which serve as non-radiative centers on the polymer surface) is confirmed by the decrease in the PL intensity.

Post irradiation effects on the graft of poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) films

International Nuclear Information System (INIS)

Geraldes, Adriana N.; Zen, Heloisa A.; Ribeiro, Geise; Ferreira, Henrique P.; Souza, Camila P.; Parra, Duclerc F.; Lugao, Ademar B.

2009-01-01

Radiation induced grafting of monomers into fluorinated polymers was designed as an alternative route to polymer modification. In this work, grafting of styrene onto poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) was studied. Radiation-induced grafting of styrene onto PFA films was investigated after simultaneous irradiation (in post-irradiation condition) using a 60 Co source. The films of PFA were irradiated at 20, 40, 80 and 100 kGy doses at room temperature and chemical changes were monitored after contact with styrene for grafting. The post-irradiation time was established between 7 and 28 days when films of PFA were maintained in styrene/toluene 1:1 v/v solution at room temperature. After these periods the grafting degrees were evaluated in the samples. The highest degree of grafting was achieved after 14 days. Chemical modifications were evaluated by infrared spectroscopic analysis (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and also by scanning electron microscopy (SEM). The degree of grafting (DOG) was determined gravimetrically. The results showed that irradiated PFA films at 100 kGy exhibited higher grafting degree. Surface analysis by SEM technique of irradiated, grafted and original films have presented an homogeneous surface. (author)

Dosimetric survey in industrial irradiators and dosimetric systems calibration

International Nuclear Information System (INIS)

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

2005-01-01

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

Interface reactions between Pd thin films and SiC by thermal annealing and SHI irradiation

Energy Technology Data Exchange (ETDEWEB)

Njoroge, E.G., E-mail: eric.njoroge@up.ac.za [Department of Physics, University of Pretoria, Pretoria (South Africa); Theron, C.C. [Department of Physics, University of Pretoria, Pretoria (South Africa); Skuratov, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Wamwangi, D. [School of Physics, University of Witwatersrand, Johannesburg (South Africa); Hlatshwayo, T.T. [Department of Physics, University of Pretoria, Pretoria (South Africa); Comrie, C.M. [MRD, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Malherbe, J.B. [Department of Physics, University of Pretoria, Pretoria (South Africa)

2016-03-15

The solid-state reactions between Pd thin films and 6H-SiC substrates induced by thermal annealing, room temperature swift heavy ion (SHI) irradiation and high temperature SHI irradiation have been investigated by in situ and real-time Rutherford backscattering spectrometry (RBS) and Grazing incidence X-ray diffraction (GIXRD). At room temperature, no silicides were detected to have formed in the Pd/SiC samples. Two reaction growth zones were observed in the samples annealed in situ and analysed by real time RBS. The initial reaction growth region led to formation of Pd{sub 3}Si or (Pd{sub 2}Si + Pd{sub 4}Si) as the initial phase(s) to form at a temperature of about 450 °C. Thereafter, the reaction zone did not change until a temperature of 640 °C was attained where Pd{sub 2}Si was observed to form in the reaction zone. Kinetic analysis of the initial reaction indicates very fast reaction rates of about 1.55 × 10{sup 15} at cm{sup −2}/s and the Pd silicide formed grew linear with time. SHI irradiation of the Pd/SiC samples was performed by 167 MeV Xe{sup 26+} ions at room temperature at high fluences of 1.07 × 10{sup 14} and 4 × 10{sup 14} ions/cm{sup 2} and at 400 °C at lower fluences of 5 × 10{sup 13} ions/cm{sup 2}. The Pd/SiC interface was analysed by RBS and no SHI induced diffusion was observed for room temperature irradiations. The sample irradiated at 400 °C, SHI induced diffusion was observed to occur accompanied with the formation of Pd{sub 4}Si, Pd{sub 9}Si{sub 2} and Pd{sub 5}Si phases which were identified by GIXRD analysis.

Gamma Irradiation Effect on Biodegradable Poly (Hydroxybutyrate) Studied by Positron Annihilation Technique

International Nuclear Information System (INIS)

Abdel-Hady, E.E.; Mohamed, S.S.

2010-01-01

-Bacterial polyesters have attracted much attention as biodegradable polymers. An ecofriendly alternative to this biodegradable material is poly-3-hydroxybutyrate (PHB) which has attracted industrial attention as an environmentally degradable plastic for a wide range of medical applications. Free volume holes in polymers play a crucial role in determining its physical properties. The Positron Annihilation Lifetime (PAL) technique has been established as a powerful probe for microstructures of polymers, in particular, angstrom-sized free volume holes. The PHB samples were irradiated using 60 Co source at room temperature with doss ranging from 5 to 300 kGy. The PAL spectra for all the samples have been measured at room temperature as a function of gamma-irradiation dose. The free volume hole size decreases with increasing the irradiation dose up to 25 kGy followed by slowly increases up to 200 kGy, then decreases at higher doses. On the other hand, the free volume content decreases with increasing the gamma-irradiation dose which is due to the increase of the degree of crystallinity. The variations in the free volume with the irradiation dose will be discussed in the frame of free volume model. A correlation between the macroscopic mechanical properties Hv and positron annihilation parameters has been done

Shelf-life extension of pre-packed whole wheat flour using low dose gamma irradiation

International Nuclear Information System (INIS)

Rao, V.S.; Marathe, S.A.; Pednekar, M.D.; Machaiah, J.P.; Rao, B.Y.K.; Adhikari, H.R.; Thomas, Paul

1997-01-01

Storage studies on irradiated (0.25, 0.5 and 1.0 kGy) and non-irradiated prepacked whole wheat flour have shown that wheat flour irradiated at 0.25 kGy and stored at room temperature for 6 months did not show significant changes in the functional qualities and acceptability of the product, thereby extending the shelf-life and marketability of the product. (author). 3 refs., 4 figs

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

International Nuclear Information System (INIS)

Thorseth, Trond Morten

2000-01-01

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

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

Energy Technology Data Exchange (ETDEWEB)

Thorseth, Trond Morten

2000-07-01

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

Utilization of half-embryo test to identify irradiated beans

International Nuclear Information System (INIS)

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

1996-01-01

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

Retention of radiolytic CO gas in irradiated pepper grains and irradiation detection of spices and dry grains with the level of stocked CO gas

International Nuclear Information System (INIS)

Furuta, M.; Dohmaru, T.; Katayama, T.; Toratani, H.; Takeda, A.

1995-01-01

The release of radiolytic CO gas from 60Co gamma-irradiated pepper seeds was unexpectedly slower than that of radiolytic H2 gas during a storage period after irradiation. These gases were retained in the grains and could be recovered by pulverization under gaslight condition. Using this procedure, 10-kGy-irradiated pepper grains could be distinguished from nonirradiated samples for more than 2 months by the level of CO and H2 gases. The patterns of CO change at 10, 20, and 30 kGy were similar, and the CO amounts were proportional to irradiation doses at any point of the storage period after irradiation. 60Co gamma-irradiated grains of allspice, cinnamon, cumin, polished rice, and wheat could be distinguished from nonirradiated ones by the level of retained CO gas even after 2 months of storage at room temperature. Thus, radiolytic CO gas could be an effective probe for rapid screening of irradiated pepper and dry grains

Colloid bands in silver chloride induced by reactor irradiation at low temperature

International Nuclear Information System (INIS)

Atobe, K.; Okada, M.; Nakagawa, M.

1978-01-01

It is well known that no trapped electron center exists stably in irradiated silver chlorides even at low temperatures. On the other hand, irradiation by ultra-violet light at room temperature produces a broad absorption (colloid bands) on the long wavelength side of the fundamental absorption. In this report, it is shown that one of the colloid bands appears in undoped AgCl crystals by reactor irradiation at low temperature (20 K) and the other colloid band by thermal annealing after the irradiation. The relation between the bands, which correspond to two types of colloidal silver, is represented. (author)

Influence of ultrasonic irradiation on ozone generation in a dielectric barrier discharge

International Nuclear Information System (INIS)

Kusano, Y; Drews, J; Leipold, F; Fateev, A; Bardenshtein, A; Krebs, N

2012-01-01

An atmospheric pressure dielectric barrier discharge (DBD) was generated in an N 2 /O 2 gas mixture at room temperature with and without ultrasonic irradiation to investigate ozone production. Powerful ultrasonic irradiation with the sound pressure level of approximately 150 dB into the DBD can enhance ozone production especially when the DBD was driven at a frequency of 15 kHz.

Extending the shelf-life of citrus fruits using irradiation and/or other treatments I. 'Balady' oranges

International Nuclear Information System (INIS)

Abd-Allah, M.A.; Khallaf, M.F.; Mahmoud, A.A.; Salem, M.H.

1996-01-01

Irradiation process (0, 1.50 and 2.50 kGy) gamma radiation with or without other treatments before irradiation, i.e. soaking in CaCl 2 solution or waxing were used in this study to investigate the effect of such treatments on the shelf-life of 'Balady' orange fruits at room temperature. Marketable properties (browning, decay and texture) in addition to the organoleptic evaluation of firmness, appearance, odour, colour and taste were detected. Results showed the preferability of waxing treatment before irradiation processes. On the other hand, statistical analysis of the organoleptic evaluation revealed that the shelf-life of untreated sample (control) was 20 days at room temperature, while samples exposed to the different suggested treatments were rejected after 30 days under the same conditions. (author)

Behavior of implanted hydrogen in ferritic/martensitic steels under irradiation

Science.gov (United States)

Wan, F.; Takahashi, H.; Ohnuki, S.; Nagasaki, R.

1988-07-01

The aim of this study was to clarify the behavior of hydrogen under irradiation in ferritic/martensitic stainless steel Fe-10Cr-2Mo-1Ni. Hydrogen was implanted into the specimens by ion accelerator or chemical cathodic charging method, followed by electron irradiation in a HVEM at temperatures from room temperature to 773 K. Streaks in the electron diffraction patterns were observed only during electron irradiation at 623-723 K. From these results it is suggested that the occurrence of the streak pattern is due to the formation of radiation-induced complexes of Ni or Cr with hydrogen along directions.

γ-irradiation effect on electronic properties in hydrogenated amorphous silicon

International Nuclear Information System (INIS)

Shirafuji, J.; Nagata, S.; Shirakawa, K.

1986-01-01

γ-irradiation effect on electron transport and photoelectric properties in glow-discharge hydrogenated amorphous silicon is investigated mainly by means of time-of-flight measurement. Although the electron transport changes from non-dispersive to dispersive when the total dose on γ-rays is increased, the electron mobility at room temperature is affected only slightly by γ-irradiation. The γ-irradiation introduces dominantly Si dangling bonds, allowing to study the recombination characteristic as a function of dangling bond density under controllable conditions. It is found that the electron recombination lifetime is inversely proportional to the dangling bond density. (author)

Evaluation of defect formation in helium irradiated Y2O3 doped W-Ti alloys by positron annihilation and nanoindentation

Science.gov (United States)

Richter, Asta; Anwand, Wolfgang; Chen, Chun-Liang; Böttger, Roman

2017-10-01

Helium implanted tungsten-titanium ODS alloys are investigated using positron annihilation spectroscopy and nanoindentation. Titanium reduces the brittleness of the tungsten alloy, which is manufactured by mechanical alloying. The addition of Y2O3 nanoparticles increases the mechanical properties at elevated temperature and enhances irradiation resistance. Helium ion implantation was applied to simulate irradiation effects on these materials. The irradiation was performed using a 500 kV He ion implanter at fluences around 5 × 1015 cm-2 for a series of samples both at room temperature and at 600 °C. The microstructure and mechanical properties of the pristine and irradiated W-Ti-ODS alloy are compared with respect to the titanium and Y2O3 content. Radiation damage is studied by positron annihilation spectroscopy analyzing the lifetime and the Doppler broadening. Three types of helium-vacancy defects were detected after helium irradiation in the W-Ti-ODS alloy: small defects with high helium-to-vacancy ratio (low S parameter) for room temperature irradiation, larger open volume defects with low helium-to-vacancy ratio (high S parameter) at the surface and He-vacancy complexes pinned at nanoparticles deeper in the material for implantation at 600 °C. Defect induced hardness was studied by nanoindentation. A drastic hardness increase is observed after He ion irradiation both for room temperature and elevated irradiation temperature of 600 °C. The Ti alloyed tungsten-ODS is more affected by the hardness increase after irradiation compared to the pure W-ODS alloy.

Fatty acids changes of baby food fat by γ irradiation

International Nuclear Information System (INIS)

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

2005-01-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

IRASM - A multipurpose irradiation facility in Romania

International Nuclear Information System (INIS)

Ponta, C.C.; Moise, I.V.; Bratu, E.

1998-01-01

A multipurpose irradiation facility is under construction at IPNE, Bucharest, under the IAEA T.C. Project: ROM/8/011. It will be the first industrial facility in Romania. This paper presents the philosophy standing behind the design, the short and long term managing plans. Some dose calculations are added in the view of using the empty spaces in the irradiation room for cultural heritage conservation. An economic study is presented aiming to provide basic estimations for further management strategy. At the start the facility will be a state enterprise. The implications, advantages and disadvantages of this situation are discussed

Irradiation application for color removal and purification of green tea leaves extract

International Nuclear Information System (INIS)

Jo, Cheorun; Son, J.H.; Lee, H.J.; Byun, M.W.

2003-01-01

Gamma irradiation was introduced to develop a new processing method for brighter-colored green tea leaves extract without changes of physiological activities. Dried green tea leaves were purchased and extracted by 70% ethanol solution and irradiated at 0, 5, 10, and 20 kGy with gamma rays. Hunter color L-value increased and a- and b-value decreased by irradiation, resulting in bright yellow from dark brown. There was no difference in radical scavenging and tyrosinase inhibition effect by irradiation. The irradiation effect in the solution disappeared during storage for 3 weeks at room temperature but vitamin C addition was effective in reducing the color change. Results indicated that irradiation may be a good technology to remove undesirable color in green tea leaves extract

The efficacy testing of irradiated shrimp paste

International Nuclear Information System (INIS)

Nouchpramool, Kovit; Eamsiri, Jaruratana; Sujjabut, Surusak

2005-10-01

Two lots of shrimp paste from commercial source in Samutsakhon were irradiated at a recommended minimum dose of 6 kGy using a J S 8900 cobalt-60 carrier gamma irradiator of Thai Irradiation Center in Patum Thani. Red Perspex dosimeter were used to measure the absorbed dose throughout the product with emphasis on the region of minimum and maximum absorbed dose. This way, it was aimed to compare the dose effects of gamma irradiation on the microbiological, chemical and sensory quality of shrimp paste. The results indicated that the shrimp paste received minimum and maximum absorbed dose of 6.85 and 12.83 kGy with dose uniformity ratio of 1.87 . Throughput rate is 468 kilogram per hour. The microbiological load of shrimp paste was rather high resulting in not compliance with Thai industrial standard 1080-2535. Irradiation at 6.8 kGy reduced total viable bacterial count by one log cycle. Although the irradiated product was organoleptic ally acceptable and could be kept for 16 months at room temperature, mold and Clostridium perfringens were still present in some samples after irradiation and during prolonged storage in amount that exceeds the limitation of Thai industrial standard. Chemical properties such as p H, moisture and sodium chloride content of irradiated shrimp paste were not significantly changed after irradiation

Recovery of the irradiated JFETs by thermal annealing

International Nuclear Information System (INIS)

Assaf, J.

2007-10-01

Study about the recovering of irradiated JFET transistors has been reported. The JFETs were damaged totally or partially by exposition to Gamma ray and neutrons. Electronics noise has used to evaluate the effect of radiation and the recovery. The study focused on the recovery by thermal annealing, where samples have been heated gradually until 140 centigrade degree (410 K). The recovery ratio given by this method was higher than that resulted from the relaxation method (time recovery) carried out in the room temperature (300 K), especially for Gamma irradiated samples.(author)

Irradiation creep lifetime analysis on first wall structure materials for CFETR

Energy Technology Data Exchange (ETDEWEB)

Ma, Bing; Peng, Lei, E-mail: penglei@ustc.edu.cn; Zhang, Xiansheng; Shi, Jingyi; Zhan, Jie

2017-05-15

Fusion reactor first wall services on the conditions of high surface heat flux and intense neutron irradiation. For China Fusion Engineering Test Reactor (CFETR) with high duty time factor, it is important to analyze the irradiation effect on the creep lifetime of the main candidate structure materials for first wall, i.e. ferritic/martensitic steel, austenite steel and oxide dispersion strengthened steel. The allowable irradiation creep lifetime was evaluated with Larson-Miller Parameter (LMP) model and finite element method. The results show that the allowable irradiation creep lifetime decreases with increasing of surface heat flux, first wall thickness and inlet coolant temperature. For the current CFETR conceptual design, the lifetime is not limited by thermal creep or irradiation creep, which indicated the room for design parameters optimization.

Effect of swift heavy ion irradiation on ethylene–chlorotrifluoroethylene copolymer

International Nuclear Information System (INIS)

Singh, Lakhwant; Devgan, Kusum; Samra, Kawaljeet Singh

2012-01-01

The swift heavy irradiation induced changes taking place in ethylene–chlorotrifluoroethylene (E–CTFE) copolymer films were investigated in correlation with the applied doses. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10 11 –3×10 12 ions cm −2 . Structural and thermal properties of the irradiated as well as pristine E–CTFE films were studied using FTIR, UV–visible, TGA, DSC and XRD techniques. Swift heavy ion irradiation was found to induce changes in E–CTFE depending upon the applied doses. - Highlights: ► Effect of swift heavy ion irradiation on E–CTFE films has been studied. ► Different structural changes in the original structure of E–CTFE are observed after irradiation with different ions. ► Swift heavy ion irradiation has made E–CTFE more prone to thermal degradation.

Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

Energy Technology Data Exchange (ETDEWEB)

Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-06-15

The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

Size optimization of stand-alone photovoltaic (PV) room air conditioners

International Nuclear Information System (INIS)

Chen, Chien-Wei; Zahedi, A.

2006-01-01

Sizing of a stand-alone PV system determines the main cost of the system. PV electricity cost is determined by the amount of solar energy received, hence the actual climate and weather conditions such as solar irradiance and ambient temperature affect the size required and cost of the system. Air conditioning demand also depends on the weather conditions. Therefore, sizing a PV powered air conditioner must consider the characteristics of local climate and temperature. In this paper, sizing procedures and special considerations for air conditioning under Melbourne's climatic conditions is presented. The reliability of various PV-battery size combinations is simulated by MATLAB. As a result, excellent system performance can be predicated.(Author)

The Cloud Project Climate Research with Accelerators

CERN Document Server

Kirkby, Jasper

2010-01-01

The current understanding of climate change in the in- dustrial age is that it is predominantly caused by anthro- pogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. How- ever, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming—and yet the mechanism is not under- stood. Estimated changes of solar irradiance on these time scales are too small to account for the climate observations. This raises the question of whether cosmic rays, which are modulated by the solar wind, may be directly affect- ing the climate, providing an effective indirect solar forcing mechanism. Indeed recent satellite observations—although disputed—suggest that cosmic rays may affect clouds un- der certain conditions. However, given the many sources of variability in the atmosphere and the lack of control of the cosmic ray flux, demonstrating overall ca...

Low temperature gamma-ray irradiation effects on polymer materials

International Nuclear Information System (INIS)

Kudoh, Hisaaki; Kasai, Noboru; Sasuga, Tsuneo; Seguchi, Tadao

1995-01-01

The gamma radiation induced degradation of glass fiber reinforced plastic (GFRP) and polymethylmethacrylate (PMMA) at 77K was examined by flexural test and gas analysis after irradiation and compared by the irradiation at room temperature. The decrease in flexural strength at break was much less at 77K than at RT. The evolution of CH 4 , CO and CO 2 was also depressed at 77K. The temperature dependence of the degradation closely relates to the local molecular motion of matrix resin during irradiation. Polytetrafluoroethylene (PTFE) was also studied by irradiation at RT, 77K and 4K in terms of tensile elongation and molecular weight. The degradation was much less at 77K and 4K than at RT, and the same between 77K and 4K. (author)

Analysis of proton irradiation products in simulated interstellar dusts by mass spectrometry

International Nuclear Information System (INIS)

Kasamatsu, Takashi; Kaneko, Takeo; Tsuchiya, Masahiko; Kobayashi, Kensei

1996-01-01

It is known that various kinds of organic compounds exist in space. In order to study the possibility of the formation of organic compounds in comets or their precursory bodies (interstellar dust grains), ice mixtures of carbon monoxide (or methane), ammonia and water made in a cryostat at 10 K ('simulated cometary ices') were irradiated with high energy protons. Irradiated ice products were warmed up to room temperature, while sublimed gases were analyzed with a quadrupole mass spectrometer. Some hydrocarbons and alcohols were detected. 'Amino acid precursors' (compounds yielding amino acids after hydrolysis) were detected in non-volatile products remaining on the substrate at room temperature. These results suggest the possible formation of organic compounds in interstellar dust grains by cosmic radiation. (author)

Neutron and gamma irradiation effects on organic insulating materials for fusion magnets

International Nuclear Information System (INIS)

Maurer, W.

1985-10-01

Available low-temperature neutron and gamma irradiation data for organic insulating materials are collected and compared with room temperature data. Only the most promising polymers in terms of mechanical strength for magnet insulation are taken into account. For characterization and comparison of different materials the 75% dose is used, i.e. the dose, where the mechanical strength is reduced by 25%, and 75% is retained. For room temperature special prepared polyimide and epoxy materials reinforced with glass fibre retained 75% of the mechanical strength up to a dose of 7x10 7 Gy. For 5 K irradiation the best epoxy material retained the 75% dose up to 1x10 7 Gy, the best polyimide material up to 1x10 8 Gy. (orig.) [de

The optimization of heat supply centralization on the basis of boiler-rooms

International Nuclear Information System (INIS)

Arshakian, D.

1992-01-01

In this article the problem of finding of the optimum of heat supply centralization of towns and insutrial districts on the basis of boiler-rooms, using organic and nuclear fuel in the natural-climatic conditions and town-building transitions of Armenia is considered. (orig.) [de

Problems of the heat transfer during the irradiation of solids

International Nuclear Information System (INIS)

Jahn, G.

1981-03-01

This report deals with the thermal problems during the irradiation of solids. Analytical and constructive solutions are outlined by some examples. Two cases are looked at: 1) the samples and the equipment are warmed up during irradiation. Thus they have to be cooled which yields a negative heat flux direction. 2) The samples shall have a suitable temperature higher than room temperature. Thus they have to be heated which yields a positive heat flux direction. (BHO)

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

International Nuclear Information System (INIS)

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

1976-01-01

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

Impact of He and Cr on defect accumulation in ion-irradiated ultrahigh-purity Fe(Cr) alloys

DEFF Research Database (Denmark)

Prokhodtseva, A.; Décamps, B.; Ramar, Amuthan

2013-01-01

The effect of He on the primary damage induced by irradiation in ultrahigh-purity (UHP) Fe and Fe(Cr) alloys was investigated by transmission electron microscopy (TEM). Materials were irradiated at room temperature in situ by TEM in a microscope coupled to two ion accelerators, simultaneously pro...

Preservation of fresh noodles by irradiation

International Nuclear Information System (INIS)

Cai Jianming

1998-01-01

At the present paper, it is studied to preserve fresh noodles by irradiation. The noodles which were irradiated by 10 kGy of 60 Co-γ rays and stored at room temperature (18-24 deg. C). The appearance of the noodles was observed, the bacteria in the noodles were examined, and the acidity of the noodles was measured during 10 days after irradiation. The results showed that the number of bacteria and the extent of acidification of the noodles were in inverse proportion to radiation dose. When the absorbed dose was less than 8 kGy, the residual bacteria in the noodles could proliferate massively in several days and acidified the noodles. The pH of these noodles decreased from 6.2 to 5.0 or less and the noodles turned into sticky during storage. When the absorbed dose reached 8-10 kGy, most of bacteria were killed and the acidity of the noodles kept about pH 6.0. The appearance of the noodles looks fresh within 10 days after irradiation. They smelled as good as fresh ones

Development of an apparatus for measuring the thermal conductivity of irradiated or non-irradiated graphite

International Nuclear Information System (INIS)

Bocquet, M.; Micaud, G.

1962-01-01

An apparatus was developed for measuring the thermal conductivity coefficient K of irradiated or non-irradiated graphite. The measurement of K at around room temperature with an accuracy of about 6% is possible. The study specimen is placed in a vacuum between a hot and a cold source which create a temperature gradient ΔΘ/ Δx in the steady state. The amount of heat transferred, Q, is deduced from the electrical power dissipated at the hot source, after allowing for heat losses. The thermal conductivity coefficient is defined as: K = Q/S. Δx/ΔΘ, S being the cross section of the sample. Systematic studies have made it possible to determine the mean values of the thermal conductivity. (authors) [fr

Experimental research on fresh mussel meat irradiated by high-dose electron beam

International Nuclear Information System (INIS)

Xiao Lin; Lu Ruifeng; Hu Huachao; Wang Chaoqi; Liu Yanna

2011-01-01

The sterilization storage of fresh mussel irradiated high-dose electron beam was studied. From the subjective assessment by the weighted average of the test and other determined parameters, it can be concluded that the flavor of fresh mussel meat sealed canned food irradiated by high-dose electron beam has not been significant affected, and various micro-organisms can be killed effectively, which means that the irradiated fresh mussel meat can be preserved for long-term at room temperature. Therefore the method might resolve the problems induced by traditional frozen preservation methods. (authors)

Recent changes in solar irradiance and infrared irradiance related with air temperature and cloudiness at the King Sejong Station, Antarctica

Science.gov (United States)

Jung, Y.; Kim, J.; Cho, H.; Lee, B.

2006-12-01

The polar region play a critical role in the surface energy balance and the climate system of the Earth. The important question in the region is that what is the role of the Antarctic atmospheric heat sink of global climate. Thus, this study shows the trends of global solar irradiance, infrared irradiance, air temperature and cloudiness measured at the King Sejong station, Antarctica, during the period of 1996-2004 and determines their relationship and variability of the surface energy balance. Annual average of solar radiation and cloudiness is 81.8 Wm-2 and 6.8 oktas and their trends show the decrease of -0.24 Wm-2yr-1(-0.30 %yr-1) and 0.02 oktas yr-1(0.30 %yr-1). The change of solar irradiance is directly related to change of cloudiness and decrease of solar irradiance presents radiative cooling at the surface. Monthly mean infrared irradiance, air temperature and specific humidity shows the decrease of -2.11 Wm^{- 2}yr-1(-0.75 %yr-1), -0.07 'Cyr-1(-5.15 %yr-1) and -0.044 gkg-1yr-1(-1.42 %yr-1), respectively. Annual average of the infrared irradiance is 279.9 Wm-2 and correlated with the air temperature, specific humidity and cloudiness. A multiple regression model for estimation of the infrared irradiance using the components has been developed. Effects of the components on the infrared irradiance changes show 52 %, 19 % and 10 % for air temperature, specific humidity and cloudiness, respectively. Among the components, air temperature has a great influence on infrared irradiance. Despite the increase of cloudiness, the decrease in the infrared irradiance is due to the decrease of air temperature and specific humidity which have a cooling effect. Therefore, the net radiation of the surface energy balance shows radiative cooling of negative 11-24 Wm^{- 2} during winter and radiative warming of positive 32-83 Wm-2 during the summer. Thus, the amount of shortage and surplus at the surface is mostly balanced by turbulent flux of sensible and latent heat.

Pyrolysis of γ-ray irradiated poly(tetrafluorethylene) powder

International Nuclear Information System (INIS)

Kagiya, Tsutomu; Yokoyama, Norio; Ueno, Toru

1974-01-01

Pyrolysis of γ-ray irradiated poly(tetrafluoroethylene) powder (PTFE) has been studied at temperatures from 200 0 C to 390 0 C in the presence of air. By heating, the weight decrease of the powder and the formation of gaseous CO 2 and CO were observed. The weight decrease of the powder increased with total dose of irradiation. γ-ray irradiated PTFE decomposed partly by heating above 250 0 C. By heating at 300 0 C, the degree of weight decrease increased with heating time and reached a constant value. While at 390 0 C, successive decomposition was observed. The melting point of PTFE was depressed by irradiation, while it did not change by heating. No change of IR spectrum of PTFE by irradiation and/or heating was observed. In the irradiated PTFE, stable peroxy radical was observed by ESR measurement at room temperature, but decreased by heating at 150 0 C and disappeared at 250 0 C. Upon pre-heating the irradiated PTFE above 200 0 C, the weight decrease of the powder at 390 0 C decreased remarkably. On the basis of these results, mechanisms of the pyrolysis and thermo-stabilization of the irradiated PTFE were discussed. (auth.)

Irradiation effects on perfluorinated polymers

International Nuclear Information System (INIS)

Lappan, U.; Geissler, U.; Haeussler, L.; Pompe, G.; Scheler, U.; Lunkwitz, K.

2002-01-01

Complete text of publication follows. High-energy radiation affects the properties of polymers by chain scission and crosslinking reactions. Both types of reaction occur simultaneously in irradiated polymers. However, one process will usually predominate, depending on the chemical structure of the polymer and the irradiation conditions such as temperature and atmosphere. Polytetrafluoroethylene (PTFE) undergoes predominantly chain scission, if the irradiation is performed at room temperature. This shortcoming is exploited by converting PTFE into low molecular weight micropowders. The use of PTFE micropowders functionalized with COOH groups as additive in polyamides to improve the sliding properties of the materials has been studied. During the compounding process in a twin screw extruder the COOH groups of the irradiated PTFE react with the polyamides. For these studies, it became necessary to investigate the content of end groups in irradiated PTFE by FTIR and 19 F solid-state NMR. These date were used to calculate number-average molecular weights. The ratios of COOH groups to CF 3 groups are discussed in terms of the mechanism of PTFE degradation. If PTFE is irradiated at temperatures above its crystalline melting point in an oxygen-free atmosphere, branching and crosslinking occur. The dependence of radiation effects on perfluorinated copolymers (FEP, PFA) on temperature has been studied. Melt flow index measurements have shown that branching and crosslinking predominate over chain scission with increasing irradiation temperature both in FEP and in PFA. Quantitative analysis of 19 F solid-state NMR data has shown that the content of branching groups (>CF-) exceeds the content of end groups in the case of PFA irradiated above its crystalline melting point. The formation of COF and COOH groups in the irradiated PFA is interpreted as a result of partial degradation of perfluorovinyl ether comonomer units

Research on sprout inhibition effect of refrigerated garlic by irradiation

International Nuclear Information System (INIS)

Zhang Xuan; He Jianzhong; Li Ruijun

2005-01-01

This paper researches the sprout inhibition effect by irradiation on refrigerated garlic. The results shows that, the garlic is still in the period of dormancy within 7 days after taken out from the refrigerated warehouse, and irradiation have a good sprout inhibition effect on it. The irradiation dose is 40-90 Gy, the same as that of the post harvest irradiation treatment on garlic. Refrigerate the Zhongmu Garlic (at -2 degree C-0 degree C) until the middle ten days of February the next year, place it at the room temperature (10 degree C-15 degree C) for 1-7 days after taking it out of the warehouse, then use 60 Co γ-ray to irradiate it until the absorbed dose reaches 40-90 Gy, the sprout inhibition effect can be realized. The test also indicates that the deposited time after taking out of the refrigerated warehouse is crucial to the sprout inhibition effect of refrigerated garlic by irradiation. (authors)

Fracture toughness of irradiated candidate materials for ITER first wall/blanket structures

International Nuclear Information System (INIS)

Alexander, D.J.; Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F.; Shiba, Kiyoyuki

1994-01-01

Disk compact specimens of candidate materials for first wall/blanket structures in ITER have been irradiated to damage levels of about 3 dpa at nominal irradiation temperatures of either 90 or 250 degrees C. These specimens have been tested over a temperature range from 20 to 250 degrees C to determine J-integral values and tearing moduli. The results show that irradiation at these temperatures reduces the fracture toughness of austenitic stainless steels, but the toughness remains quite high. The toughness decreases as the test temperature increases. Irradiation at 250 degrees C is more damaging than at 90 degrees C, causing larger decreases in the fracture toughness. Ferritic-martensitic steels are embrittled by the irradiation, and show the lowest toughness at room temperature

Tuning the conductivity of vanadium dioxide films on silicon by swift heavy ion irradiation

Directory of Open Access Journals (Sweden)

H. Hofsäss

2011-09-01

Full Text Available We demonstrate the generation of a persistent conductivity increase in vanadium dioxide thin films grown on single crystal silicon by irradiation with 1 GeV 238U swift heavy ions at room temperature. VO2 undergoes a temperature driven metal-insulator-transition (MIT at 67 °C. After room temperature ion irradiation with high electronic energy loss of 50 keV/nm the conductivity of the films below the transition temperature is strongly increased proportional to the ion fluence of 5·109 U/cm2 and 1·1010 U/cm2. At high temperatures the conductivity decreases slightly. The ion irradiation slightly reduces the MIT temperature. This observed conductivity change is persistent and remains after heating the samples above the transition temperature and subsequent cooling. Low temperature measurements down to 15 K show no further MIT below room temperature. Although the conductivity increase after irradiation at such low fluences is due to single ion track effects, atomic force microscopy (AFM measurements do not show surface hillocks, which are characteristic for ion tracks in other materials. Conductive AFM gives no evidence for conducting ion tracks but rather suggests the existence of conducting regions around poorly conducting ion tracks, possible due to stress generation. Another explanation of the persistent conductivity change could be the ion-induced modification of a high resistivity interface layer formed during film growth between the vanadium dioxide film and the n-Silicon substrate. The swift heavy ions may generate conducting filaments through this layer, thus increasing the effective contact area. Swift heavy ion irradiation can thus be used to tune the conductivity of VO2 films on silicon substrates.

Total and Spectral Solar Irradiance Sensor (TSIS) Project Status

Science.gov (United States)

Carlisle, Candace

2018-01-01

TSIS-1 studies the Sun's energy input to Earth and how solar variability affects climate. TSIS-1 will measure both the total amount of light that falls on Earth, known as the total solar irradiance (TSI), and how that light is distributed among ultraviolet, visible and infrared wavelengths, called solar spectral irradiance (SSI). TSIS-1 will provide the most accurate measurements of sunlight and continue the long-term climate data record. TSIS-1 includes two instruments: the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM), integrated into a single payload on the International Space Station (ISS). The TSIS-1 TIM and SIM instruments are upgraded versions of the two instruments that are flying on the Solar Radiation and Climate Experiment (SORCE) mission launched in January 2003. NASA Goddard's TSIS project responsibilities include project management, system engineering, safety and mission assurance, and engineering oversight for TSIS-1. TSIS-1 was installed on the International Space Station in December 2017. At the end of the 90-day commissioning phase, responsibility for TSIS-1 operations transitions to the Earth Science Mission Operations (ESMO) project at Goddard for its 5-year operations. NASA contracts with the University of Colorado Laboratory for Atmospheric and Space Physics (LASP) for the design, development and testing of TSIS-1, support for ISS integration, science operations of the TSIS-1 instrument, data processing, data evaluation, calibration and delivery to the Goddard Earth Science Data and Information Services Center (GES DISC).

Non-climatic thermal adaptation: implications for species' responses to climate warming.

Science.gov (United States)

Marshall, David J; McQuaid, Christopher D; Williams, Gray A

2010-10-23

There is considerable interest in understanding how ectothermic animals may physiologically and behaviourally buffer the effects of climate warming. Much less consideration is being given to how organisms might adapt to non-climatic heat sources in ways that could confound predictions for responses of species and communities to climate warming. Although adaptation to non-climatic heat sources (solar and geothermal) seems likely in some marine species, climate warming predictions for marine ectotherms are largely based on adaptation to climatically relevant heat sources (air or surface sea water temperature). Here, we show that non-climatic solar heating underlies thermal resistance adaptation in a rocky-eulittoral-fringe snail. Comparisons of the maximum temperatures of the air, the snail's body and the rock substratum with solar irradiance and physiological performance show that the highest body temperature is primarily controlled by solar heating and re-radiation, and that the snail's upper lethal temperature exceeds the highest climatically relevant regional air temperature by approximately 22°C. Non-climatic thermal adaptation probably features widely among marine and terrestrial ectotherms and because it could enable species to tolerate climatic rises in air temperature, it deserves more consideration in general and for inclusion into climate warming models.

The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

Energy Technology Data Exchange (ETDEWEB)

Lee, Ju-Woon [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Oh, Sang-Hee [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Kim, Jae-Hun [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Byun, Eui-Hong [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Ree Kim, Mee [Department of Food and Nutrition, Chungnam National University, Gung-Dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Science and Technology, Government Complex-Gwacheon, Kyunggi 427-715 (Korea, Republic of); Byun, Myung-Woo [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of)]. E-mail: mwbyun@kaeri.re.kr

2007-05-15

The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring.

The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

International Nuclear Information System (INIS)

Lee, Ju-Woon; Oh, Sang-Hee; Kim, Jae-Hun; Byun, Eui-Hong; Ree Kim, Mee; Baek, Min; Byun, Myung-Woo

2007-01-01

The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring

Thermal energy storage and losses in a room-Trombe wall system located in Mexico

International Nuclear Information System (INIS)

Hernández-López, I.; Xamán, J.; Chávez, Y.; Hernández-Pérez, I.; Alvarado-Juárez, R.

2016-01-01

A thermal evaluation of a R-TW system (room with a Trombe wall) is presented. Hourly climatic data of the coldest and the warmest days of 2014 was used to assess the behavior of the R-TW in two cities of Mexico with cold climate (Huitzilac and Toluca). The simulations were done with an in-house code based on the Finite Volume Method. It was found that thermal energy losses through the semitransparent wall are about 60% of the solar radiation incident on the system (G_s_o_l). Despite of the thermal losses, the system gets enough energy to keep the air inside the room with a temperature above 35 °C. For both cities during the coldest day, the maximum energy stored is about 109 MJ and during the warmest day is about 70 MJ. This energy is supplied from the storage wall to the air inside the room during periods without insolation. - Highlights: • Thermal performance of a Room-Trombe Wall system was evaluated under two cold cities. • Thermal energy losses through the semitransparent wall were about 60% of the solar radiation incident of the system. • The maximum energy stored by the Trombe Wall was 109 MJ during the coldest day. • The maximum energy stored by the Trombe Wall was 70 MJ during the warmest day.

The effect of gamma irradiation on curcumin component of Curcuma domestica

Science.gov (United States)

Chosdu, R.; Erizal; Iriawan, T.; Hilmy, N.

1995-02-01

The effect of gamma irradiation on curcumin component of Curcuma domestica rhizome were investigated. Pure curcumin, sliced and powdered rhizome with 10% of moisture content were irradiated at 0, 10, 30 and 50 kGy (dose rate of 6 kGy/h). Curcumin content was analysed using HPLC method and ESR spectra. Results show that free radicals are already present in unirradiated rhizome. Gamma irradiation at the doses of 10, 30 and 50 kGy induced the free radicals formation of pure curcumin and Curcuma domestica rhizome. The ESR spectra of irradiated rhizome gave a very similar spectra to the signal of irradiated pure curcumin. The percentage of free radicals intensity from pure curcumin was very stable at room temperature up to 670 hours of storage. However, the percentage intensity of free radicals in the irradiated rhizome were decay during storage. Irradiation treatment and storage time did not give a significant change on curcumin content, water activity, pH and moisture content of rhizome investigated.

The effect of gamma irradiation on curcumin component of Curcuma domestica

Energy Technology Data Exchange (ETDEWEB)

Chosdu, R.E.; Erizal; Iriawan, T.; Hilmy, N. [National Atomic Energy Agency, Jakarta (Indonesia). Center for Applications of Isotopes and Radiation

1995-10-01

The effect of gamma irradiation on curcumin component of Curcuma domestica rhizome were investigated. Pure curcumin, sliced and powdered rhizome with 10% of moisture content were irradiated at 0, 10, 30 and 50 kGy (dose rate of 6 kGy/h). Curcumin content was analysed using HPLC method and ESR spectra. Results show that free radicals are already present in unirradiated rhizome. Gamma irradiation at the doses of 10, 30 and 50 kGy induced the free radicals formation of pure curcumin and curcuma domestica rhizome. The ESR spectra of irradiated rhizome gave a very similar spectra to the signal of irradiated pure curcumin. The percentage of free radicals intensity from pure curcumin was very stable at room temperature up to 670 hours of storage. However, the percentage intensity of free radicals in the irradiated rhizome were decay during storage. Irradiation treatment and storage time did not give a significant change on curcumin content, water activity, pH and moisture content of rhizome investigated. (Author).

The effect of gamma irradiation on curcumin component of Curcuma domestica

International Nuclear Information System (INIS)

Chosdu, R.E.; Erizal; Iriawan, T.; Hilmy, N.

1995-01-01

The effect of gamma irradiation on curcumin component of Curcuma domestica rhizome were investigated. Pure curcumin, sliced and powdered rhizome with 10% of moisture content were irradiated at 0, 10, 30 and 50 kGy (dose rate of 6 kGy/h). Curcumin content was analysed using HPLC method and ESR spectra. Results show that free radicals are already present in unirradiated rhizome. Gamma irradiation at the doses of 10, 30 and 50 kGy induced the free radicals formation of pure curcumin and curcuma domestica rhizome. The ESR spectra of irradiated rhizome gave a very similar spectra to the signal of irradiated pure curcumin. The percentage of free radicals intensity from pure curcumin was very stable at room temperature up to 670 hours of storage. However, the percentage intensity of free radicals in the irradiated rhizome were decay during storage. Irradiation treatment and storage time did not give a significant change on curcumin content, water activity, pH and moisture content of rhizome investigated. (Author)

Irradiation effects of high temperature superconductor of lanthanoid oxides

Energy Technology Data Exchange (ETDEWEB)

Ueda, Koh-ichi; Kohara, Takao [Himeji Inst. of Tech., Hyogo (Japan)

1996-04-01

Neutron irradiation effects on excess oxygen were studied by neutron irradiation on La{sub 2}CuO{sub 4} treated with high pressure oxygen. La{sub 2}CuO{sub 4} was prepared by the usual method and annealed for 10 h under the oxygen pressure of 800-2000 atm. at 600degC. The superconducting transition temperature (Tc) is 27-32K before irradiation (La{sub 2}CuO{sub 4+d}, amount of excess oxygen d=0.03-0.12). Neutron irradiation was carried out by two kinds of experiments. Low irradiation dose test at low temperature (LTL: {approx}20-200K, storage in LN{sub 2}) showed Tc decreased more slowly than that of high temperature range. Experiment at high temperature (Hyd:{approx}80deg{yields}, storage at room temperature) showed -10K/10{sup 18}n/cm{sup 2}, the decrease of Tc was three times larger than that of YBCO type superconductor. (S.Y.)

Studies on the storage of irradiated potatoes

Energy Technology Data Exchange (ETDEWEB)

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

1995-10-01

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

Studies on the storage of irradiated potatoes

International Nuclear Information System (INIS)

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

1995-01-01

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

Helium effects on irradiation dmage in V alloys

Energy Technology Data Exchange (ETDEWEB)

Doraiswamy, N.; Alexander, D. [Argonne National Lab., IL (United States)

1996-10-01

Preliminary investigations were performed on V-4Cr-4Ti samples to observe the effects of He on the irradiation induced microstructural changes by subjecting 3 mm electropolished V-4Cr-4Ti TEM disks, with and without prior He implantation, to 200 keV He irradiation at room temperature and monitoring, in-situ, the microstructural evolution as a function of total dose with an intermediate voltage electron microscope directly connected to an ion implanter. A high density of black dot defects were formed at very low doses in both He pre-implanted and unimplanted samples.

Control room philosophy: Principles of control room design and control room work

International Nuclear Information System (INIS)

Skriver, Jan; Ramberg, Jasmine; Allwin, Pernilla

2006-01-01

In order to provide insights for improvement of work in control rooms several factors have to be considered. Knowledge of principles including control room philosophies will guide the recommended improvements. In addition to knowledge about specific principles an advantage for an organization can be an understanding of similarities and policies used in other high risk industry. The report has been developed on the basis of a document analysis of international standards and other guiding documents. (NUREG 0711, ISO 11064, ISO 6385, IEC 60964). In addition to the document analysis which has strived to compare the documents to see similarities in important principals, experience from working with control room design, modifications and evaluations in other high risk industries has pervaded the report. Important principles have been identified which are recommended to be included in a control room philosophy. Many of these are similar to the principles identified in the international standards. An additional principal which is regarded as important is the utilization of Key Performance Indicators (KPI) which can be used as a measure to target preventative means. Further more it is critical that the control room philosophy is easy to access and comprehend for all users. One of the challenges that remain after having developed a control room philosophy is how to utilize it in the daily work situation. It is vital that the document remains as a living document, guiding the continual improvement of the control room in the various life cycle stages

Structural changes induced by electron irradiation

International Nuclear Information System (INIS)

Koike, J.; Pedraza, D.F.

1993-01-01

Highly oriented pyrolytic graphite was irradiated at room temperature with 300 kV electrons. Transmission electron microscopy and electron energy loss spectroscopy were employed to study the structural changes produced by irradiation. The occurrence of a continuous ring intensity in the selected area diffraction (SAD) pattern obtained on a specimen irradiated with the electron beam parallel to the c-crystallographic axis indicated that microstructural changes had occurred. However, from the SAD pattern obtained for the specimens tilted relative to the irradiation direction, it was found that up to a fluence of 1.1x10 27 e/m 2 graphite remained crystalline. An SAD pattern of a specimen irradiated with the electron beam perpendicular to the c-axis confirmed the persistence of crystalline order. High resolution electron microscopy showed that ordering along the c-axis direction remained. A density reduction of 8.9% due to irradiation was determined from the plasmon frequency shift. A qualitative model is proposed to explain these observations. A new determination of the threshold displacement energy, Ed, of carbon atoms in graphite was done by examining the appearance of a continuous ring in the SAD pattern at various electron energies. A value of 30 eV was obtained whether the incident electron beam was parallel or perpendicular to the c-axis, demonstrating that Ed is independent of the displacement direction

Construction of a reliable model pyranometer for irradiance ...

African Journals Online (AJOL)

USER

2010-03-22

Mar 22, 2010 ... Key words: Solar radiation, pyranometer, photodiode, irradiance. INTRODUCTION ... used in meteorology, climate- logy, agriculture, solar energy studies and building ..... Renewable Energy, 9: 30-33. Energy Commission of ...

Solvent effect on post-irradiation grafting of styrene onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) films

Science.gov (United States)

Napoleão Geraldes, Adriana; Augusto Zen, Heloísa; Ribeiro, Geise; Fernandes Parra, Duclerc; Benévolo Lugão, Ademar

2013-03-01

Radiation-induced grafting of styrene onto ETFE films in different solvent was investigated after simultaneous irradiation (in post-irradiation condition) using a 60Co source. Grafting of styrene followed by sulfonation onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) are currently studied for synthesis of ion exchange membranes. The ETFE films were immersed in styrene/toluene, styrene/methanol and styrene/isopropyl alcohol and irradiated at 20 and 100 kGy doses at room temperature. The post-irradiation time was established at 14 day and the grafting degree was evaluated. The grafted films were sulfonated using chlorosulfonic acid and 1,2-dichloroethane 20:80 (v/v) at room temperature for 5 h. The degree of grafting (DOG) was determined gravimetrically and physical or chemical changes were evaluated by differential scanning calorimeter analysis (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The ion exchange capacity (IEC) values showed the best performance of sulfonation for ETFE membranes grafted in toluene solvent. Surface images of the grafted films by SEM technique have presented a strong effect of the solvents on the films morphology.

Food irradiation dosimetry using thermoluminescence of quartz sand

International Nuclear Information System (INIS)

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

1993-01-01

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

On enzyme kinetic parameters modification of gamma irradiation

International Nuclear Information System (INIS)

Ferdes, O.S.; Ferdes, M.; Turcu, G.R.

1993-01-01

To elucidate the molecular mechanisms of gamma-ray action on biomolecules there were investigated the modifications in activity and other kinetic parameters for some enzymes irradiated in pure dry state at relative high doses. There were considered bacterial and fungal α-amylases, glucoamylase and Mucor sp. protease irradiated by a 60 Co gamma-ray source in the dose range 1.0-30.0 kGy, at different dose-rates between 0.5-2.0 kGy/h, at room temperature. Considering the enzyme inactivation in this dose range, the dose-effect relationships have an expected form and depend on the irradiation conditions but not significantly on the dose rate. The catalytic properties of enzymes were modified by irradiation. By usual methods it is evidenced a direct correlation between the enzymatic activities, Michaelis-Menten constant, K m , reaction velocities, v, and the irradiation dose. These experimental findings can support a self-consistent theoretical approach on biophysical radiation action on biological active molecules like enzymes. At the same time, some enzyme behaviour to irradiation could be considered like a good biological indicator of radiation response. (Author) 4 Figs., 19 Refs

Defect studies in electron-irradiated ZnO and GaN

International Nuclear Information System (INIS)

Tuomisto, F.; Look, D.C.; Farlow, G.C.

2007-01-01

We present experimental results obtained with positron annihilation spectroscopy in room-temperature electron-irradiated n-type ZnO and GaN. The cation vacancies act as important compensating centers in 2 MeV electron-irradiated samples, even though their introduction rates are different by 2 orders of magnitude. In addition, negatively charged non-open volume defects that also compensate the n-type conductivity are produced together with the cation vacancies at similar introduction rates. The low introduction rates of compensating defects in ZnO demonstrate the radiation hardness of the material. Isochronal thermal annealings were performed to study the dynamics of the irradiation-induced defects. In 2 MeV electron-irradiated ZnO, all the defects introduced in the irradiation disappear already at 600 K, while 1100 K is needed in GaN. Several separate annealing stages of the defects are observed in both materials, the first at 400 K

Defect studies in electron-irradiated ZnO and GaN

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, F. [Laboratory of Physics, Helsinki University of Technology, 02015 TKK Espoo (Finland)], E-mail: filip.tuomisto@tkk.fi; Look, D.C. [Semiconductor Research Center, Wright State University, Dayton, OH 45435 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 (United States); Farlow, G.C. [Physics Department, Wright State University, Dayton, OH 45435 (United States)

2007-12-15

We present experimental results obtained with positron annihilation spectroscopy in room-temperature electron-irradiated n-type ZnO and GaN. The cation vacancies act as important compensating centers in 2 MeV electron-irradiated samples, even though their introduction rates are different by 2 orders of magnitude. In addition, negatively charged non-open volume defects that also compensate the n-type conductivity are produced together with the cation vacancies at similar introduction rates. The low introduction rates of compensating defects in ZnO demonstrate the radiation hardness of the material. Isochronal thermal annealings were performed to study the dynamics of the irradiation-induced defects. In 2 MeV electron-irradiated ZnO, all the defects introduced in the irradiation disappear already at 600 K, while 1100 K is needed in GaN. Several separate annealing stages of the defects are observed in both materials, the first at 400 K.

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

The use of shore wave ultraviolet radiation for disinfection in operating rooms

International Nuclear Information System (INIS)

Baanrud, H.; Moan, J.

1999-01-01

Over a number of years short wave ultraviolet radiation (UVC;200-280 nm) has been used to disinfect air and surfaces in operating rooms, patient rooms and laboratories, as well as air in ventilation ducts. Despite the well-documented effect of ultraviolet radiation on air quality, this technology has been relatively little used. One advantage of this method is that the UVC sources ensure a continuous reduction in the number of airborne microorganisms that are generated all the time. There are, however, some disadvantages with this method. Human exposure to ultraviolet C may cause keratoconjunctivitis and erythema and requires protection of the skin and the eyes of people exposed to levels above recommended exposure limits. However, by enclosing the UVC sources or by irradiation in the absence of human activity, human exposure is eliminated. These and other aspects concerning the use of short wave ultraviolet radiation as a disinfection agent in operating rooms are discussed in this article

Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Tadayoshi; Tsujimura, Norio [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Oyanagi, Katsumi [Japan Radiation Engineering Co., Ltd., Hitachi, Ibaraki (Japan)

2002-09-01

Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, {sup 241}Am-Be and {sup 252}Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

Evaluation of room-scattered neutrons at the JNC Tokai neutron reference field

International Nuclear Information System (INIS)

Yoshida, Tadayoshi; Tsujimura, Norio

2002-01-01

Neutron reference fields for calibrating neutron-measuring devices in JNC Tokai Works are produced by using radionuclide neutron sources, 241 Am-Be and 252 Cf sources. The reference field for calibration includes scattered neutrons from the material surrounding sources, wall, floor and ceiling of the irradiation room. It is, therefore, necessary to evaluate the scattered neutrons contribution and their energy spectra at reference points. Spectral measurements were performed with a set of Bonner multi-sphere spectrometers and the reference fields were characterized in terms of spectral composition and the fractions of room-scattered neutrons. In addition, two techniques stated in ISO 10647, the shadow-cone method and the polynomial fit method, for correcting the contributions from the room-scattered neutrons to the readings of neutron survey instruments were compared. It was found that the two methods gave an equivalent result within a deviation of 3.3% at a source-to-detector distance from 50cm to 500cm. (author)

Gamma ray irradiation induced optical band gap variations in silica sol-gel doped sucrose

International Nuclear Information System (INIS)

Marzouki, F.; Farah, K.; Hamzaoui, A.H; Ben Ouada, H

2015-01-01

The silica xerogels doped sucrose was prepared via sol-gel process and exposed at room temperature to different doses of high energy ("6"0Co) gamma irradiation. Changes in the UV-visible and FTIR spectra of pristine and irradiated xerogels with varying of gamma doses rays show variation in the gap energy. It was found that energy gap of the investigated silica xerogels decreases with increasing the gamma irradiation doses. Thereby the irradiated samples reveal behaviour changes, from an insulator (Eg ∼5,8 eV) towards a semiconductor with (Eg ∼ 3.5 eV).

Investigation of physical detection markers in irradiated foods under different radiation sources and post-irradiation storage conditions

Energy Technology Data Exchange (ETDEWEB)

Kwon, Joong Ho; Kim, Gui Ran; Ahn, Jae Jun; Kim, Dong Gil; Jin, Qiong Wen; Park, Ju Hwan; Lee, Ji Hyun [Kyungpook National University, Daegu (Korea, Republic of)

2010-04-15

In PSL analysis, all unirradiated samples showed less than 700 (negative) photon counts (PCs). At 5 kGy, spice samples showed PCs in range of 700-5,000 (intermediate), while grains, legumes, root-crops, and seasonings samples showed PCs over 5,000 (positive). This PSL based-detection of radiation treatment was possible even after 24 months of storage. In TL analysis, TL glow curve was characteristically different between unirradiated and irradiated samples. Glow curves were observed in temperature ranges of 150-250 .deg. C for irradiated and over 300 .deg. C for unirradiated samples. TL ratio (TL{sub 1}/TL{sub 2}) provided valuable additional confirmations as unirradiated sample showed values less than 0.1, while irradiated sample showed more than 0.1. However, with storage time, TL intensity and TL ratio decreased but discrimination was still possible even after storage of 24 months. Samples stored at room temperature with exposure to direct or indirect light enhanced the mentioned decrease of TL intensity and TL ratio as compared to low temperature storage in dark room. In ESR analysis, legumes and spices showed radiation-induced cellulose radicals, while seasonings showed multi-component signals of radiation-induced crystalline sugar radical. These radiation-induced radicals could be potential markers for the detection of radiation treatments in subjected samples. The decreasing trend was also found for radiation-specific ESR signals of cellulose and crystalline sugar radicals during storage. However, radiation-induced radicals in legumes, powdered pepper and seasonings were detectable even after 6 months of storage

Biochemical effects of gamma irradiation on banana fruits

International Nuclear Information System (INIS)

El-Motaium, R.A.

1980-01-01

It is of important to study the extension of shelf-life at ambient temperature. This study would be of significant in the case of non- refrigerated transport, practices within the country and transhipment to distant countries. studies have therefore extended to assess the shelf-life of irradiated banana stored under-room temperature. Extension of shelf -life have been achieved by many methods, the most modern one is using gamma irradiation as a promising technology for developing nations. the aim of this investigation is to study the biochemical effects of gamma irradiation on G ros Michel m ature green banana fruits and also to determine the optimum dose level and the optimum storage conditions which resulted in, keeping the organoleptic qualities as it is and maximum extension in shelf-life

Post-irradiation effects in CMOS integrated circuits

International Nuclear Information System (INIS)

Zietlow, T.C.; Barnes, C.E.; Morse, T.C.; Grusynski, J.S.; Nakamura, K.; Amram, A.; Wilson, K.T.

1988-01-01

The post-irradiation response of CMOS integrated circuits from three vendors has been measured as a function of temperature and irradiation bias. The author's have found that a worst-case anneal temperature for rebound testing is highly process dependent. At an anneal temperature of 80 0 C, the timing parameters of a 16K SRAM from vendor A quickly saturate at maximum values, and display no further changes at this temperature. At higher temperature, evidence for the anneal of interface state charge is observed. Dynamic bias during irradiation results in the same saturation value for the timing parameters, but the anneal time required to reach this value is longer. CMOS/SOS integrated circuits (vendor B) were also examined, and showed similar behavior, except that the saturation value for the timing parameters was stable up to 105 0 C. After irradiation to 10 Mrad(Si), a 16K SRAM (vendor C) was annealed at 80 0 C. In contrast to the results from the vendor A SRAM, the access time decreased toward prerad values during the anneal. Another part irradiated in the same manner but annealed at room temperature showed a slight increase during the anneal

Effects of gamma irradiation on ripening process of Morn-Thong durian

International Nuclear Information System (INIS)

Sudto, T.; Uthairatanakij, A.; Jitareerat, P.; Photchanachai, S.; Vaongcheeree, S.

2005-09-01

The effects of gamma irradiation on ripening process of ''Morn-Thong'' durian were studied. Fruits were irradiated with gamma ray at 0, 0.3, 0.6 and 1.0 kGy or dipped Benomyl r at 500 mg/L and then fruit were stored at room temperature. Soluble solids content (SSC), pulp colour (L*, a* and b* values), flesh firmness and weight loss were measured. The results found that irradiation at 0.3 kGy caused higher water loss compared to fruit treated with 0.6, 1.0 kGy, control and Benomyl r dipping, respectively. Fruit irradiated with 0.3 kGy had the highest SSC, indicating the induce of ripening process. However, there was inconsistent in pulp colour

Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice extract

International Nuclear Information System (INIS)

Al-Adawi, M. A.; Al-Kaed, A.; Al-Bachir, M.

2002-08-01

Extract of licorice roots were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60 C package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on extract, chemical changes and sensory properties of produced juice of licorice were evaluated after 0 and 12 months or storage. The results indicated that gamma irradiation reduced the counts of microorganisms. D 10 of total count and klebsiella spp. were about 14 and 0.7 kGy respectively. The mineral ions (Na, Ca and K) concentration in juice produced from irradiated extract were lower than non-irradiated ones. Glycyrrhetinic acid and maltose concentration in juice produced from irradiated extract were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences (P> 0.05) were fond between juice produced from irradiated and unirradiated extract in color, taste, or odor. (author)

Thermal conductivity degradation of graphites due to neutron irradiation at low temperature

International Nuclear Information System (INIS)

Snead, L.L.; Burchell, T.D.

1995-01-01

Several graphites and carbon/carbon composites (C/C's) have been irradiated with fission neutrons near 150 C and at fluences up to a displacement level of 0.24 dpa. The unirradiated room temperature thermal conductivity of these materials varied from 114 W/m K for H-451 isotropic graphite, to 670 W/m K for a unidirectional FMI-1D C/C composite. At the irradiation temperature a saturation reduction in thermal conductivity was seen to occur at displacement levels of approximately 0.1 dpa. All materials were seen to degrade to approximately 10 to 14% of their original thermal conductivity after irradiation. The significant recovery of thermal conductivity due to post-irradiation isochronal anneals is also presented. (orig.)

Mixed field dosimetry in the FRN exposure-room

International Nuclear Information System (INIS)

Jentzsch, U.

1976-01-01

The twin ionization chamber technique, chemical dosimeter systems and silicon diodes have been used to determine the neutron and gamma components of the reactor field in the FRN exposure-room. The knowledge of these components are of fundamental importance for irradiation experiments in the biological research program started at the FRN. The chemical systems and silicon diodes have the advantage of low cost and simple handling. Furthermore, silicon diodes have negligible gamma response and the shift of neutron response with variation of neutron energy spectrum is small. The results of measurements with the different methods have been compared and discussed. (author)

Lattice damage caused by the irradiation of diamond

CERN Document Server

Campbell, B; Mainwood, A; Newton, M; Davies, G

2002-01-01

Diamond is perceived to be radiation-hard, but the damage caused to the diamond is not well understood. The intrinsic defects (vacancies and interstitials) which are created by radiation damage are immobile at room temperature in diamond, unlike in silicon. Therefore, once the mechanisms of damage are understood for one type and energy of the particle, the dose and energy dependence of irradiation by other particles at a range of energies can be extrapolated. When a crystal is irradiated, the generation rates of vacancies and self-interstitials are generally determined by optical or electron paramagnetic resonance (EPR) spectroscopy experiments carried out after the irradiation has stopped. However, as the irradiation proceeds some of the carbon atoms displaced from their lattice sites may relax back into the vacant site, and the damage event will not be observed in the later measurement. In this paper, the mechanisms for radiation damage by charged particles in particular electrons and photons are investigat...

Irradiation-induced patterning in dilute Cu–Fe alloys

International Nuclear Information System (INIS)

Stumphy, B.; Chee, S.W.; Vo, N.Q.; Averback, R.S.; Bellon, P.; Ghafari, M.

2014-01-01

Compositional patterning in dilute Cu 1−x Fe x (x ≈ 12%) induced by 1.8 MeV Kr + irradiation was studied as a function of temperature using atom probe tomography. Irradiation near room temperature led to homogenization of the sample, whereas irradiation at 300 °C and above led to precipitation and macroscopic coarsening. Between these two temperatures the irradiated alloys formed steady state patterns of composition where precipitates grew to a fixed size. The size in this regime increased somewhat with temperature. It was also observed that the steady state concentrations of Fe in Cu matrix and Cu in the Fe precipitates both greatly exceeded their equilibrium solubilities, with the degree of supersaturation in each phase decreasing with increasing temperature. In the macroscopic coarsening regime, the Fe-rich precipitates showed indications of a “cherry-pit” structure, with Cu precipitates forming within the Fe precipitates. In the patterning regime, interfaces between Fe-rich precipitates and the Cu-rich matrix were irregular and diffuse

Swelling of spinel after low-dose neutron irradiation

International Nuclear Information System (INIS)

Coghlan, W.A.; Clinard, F.W. Jr.; Itoh, N.; Greenwood, L.R.

1986-01-01

Swelling was determined in samples of single-crystal MgAl 2 O 4 spinel, irradiated to doses as high as 8 x 10 22 n/m 2 (E > 0.1 MeV) at approx. =50 0 C in the Omega West Reactor. Swelling effectively saturated at approx. =2 x 10 22 n/m 2 which corresponds to a damage level of only approx. =2 x 10 -3 dpa. In addition subsequent measurements after irradiation have revealed that the samples continued swelling for several weeks. These results imply that irradiation defects begin to interact by recombination and aggregation at low damage levels in this material at 50 0 C and perhaps continue to cluster at room temperature after irradiation. Rate equations have been employed to determine defect concentrations at saturation. Results to date show that the observed swelling is consistent with the number of surviving defects if swelling per Frenkel defect pair is taken to be one atomic volume

Man and the climate; L'homme et le climat (1)

Energy Technology Data Exchange (ETDEWEB)

Dron, D.; Hirschhorn, C.

2002-07-01

The aim of this report is explain and balance the real dangers associated with the climate changes that may result from human activities, those which lack some scientific background, and the precaution and prudence needs which are claimed by human beings and society. The main parts of the report are: the scientific aspects of climate changes (inventory of present knowledge, assessment of uncertainties; what are greenhouse effect, which sectors of human activities are emitting greenhouse gases, what are the threats for our planet); the international negotiations on climate (their stakes and problematic since the start of the 90's, is a world consensus possible?); the room for maneuver on economical, social and technological levels in order to decrease the greenhouse gas emissions and allocate the application of solutions between States, enterprises and citizens

Ftir study of gamma irradiation LDPE film in air

International Nuclear Information System (INIS)

Moura, Esperidiana A.B.; Silva, Andre L.A.; Gouvea, Paulo H.D.; Silva, Leonardo G. Andrade e; Gouvea, Douglas; Castro, Ricardo H.R.; Wiebeck, Helio; Kawano, Yoshio

2003-01-01

The use of the ionizing radiation for application in plastic packaging, to improve some of properties and for radiation sterilization, has been gaining popularity in the packaging industry. As a consequence of the irradiation, plastic packaging materials can undergo some chemical and physical alterations in their basic function, mainly concerning the protection characteristics. Since changes in physical properties of irradiated packaging films reflect radiation-induced chemical changes in molecular structure, in this work, an investigation was performed by Ftir analysis of LDPE film before and after radiation. Film samples were irradiated with doses between 0 Gy and 100 kGy, at room temperature and in the presence of air. The results showed alterations in the molecular structure, according to the absorbed radiation dose. (author)

Stability of lithium niobate on irradiation at elevated temperature

International Nuclear Information System (INIS)

Primak, W.; Gavin, A.P.; Anderson, T.T.; Monahan, E.

1977-01-01

In contrast to results obtained for neutron irradiation in a thermal reactor near room temperature, lithium niobate plates irradiated in the Experimental Breeder Reactor II (EBR-II) did not become metamict. This is attributed to the elevated temperature of the EBR-II. Ion bombardment experiments indicate that to avoid disordering of lithium niobate on irradiation, its temperature should be maintained above 673 K. Evidence for ionic conductivity was found at 873 K, indicating that it would be inadvisable to permit the temperature to rise that high, particularly with voltage across the plate. In reactor application as a microphone transducer, it is tentatively recommended that the lithium niobate be maintained in the middle of this temperature range for a major portion of reactor operating time

Attitudes to teamwork and safety among Italian surgeons and operating room nurses.

Science.gov (United States)

Prati, Gabriele; Pietrantoni, Luca

2014-01-01

Previous studies have shown that surgical team members' attitudes about safety and teamwork in the operating theatre may play a role in patient safety. The aim of this study was to assess attitudes about teamwork and safety among Italian surgeons and operating room nurses. Fifty-five surgeons and 48 operating room nurses working in operating theatres at one hospital in Italy completed the Operating Room Management Attitudes Questionnaire (ORMAQ). Results showed several discrepancies in attitudes about teamwork and safety between surgeons and operating room nurses. Surgeons had more positive views on the quality of surgical leadership, communication, teamwork, and organizational climate in the theatre than operating room nurses. Operating room nurses reported that safety rules and procedures were more frequently disregarded than the surgeons. The results are only partially aligned with previous ORMAQ surveys of surgical teams in other countries. The differences emphasize the influence of national culture, as well as the particular healthcare system. This study shows discrepancies on many aspects in attitudes to teamwork and safety between surgeons and operating room nurses. The findings support implementation and use of team interventions and human factor training. Finally, attitude surveys provide a method for assessing safety culture in surgery, for evaluating the effectiveness of training initiatives, and for collecting data for a hospital's quality assurance programme.

Is there room for geoengineering in the optimal climate policy mix?

International Nuclear Information System (INIS)

Bahn, Olivier; Chesney, Marc; Gheyssens, Jonathan; Knutti, Reto; Pana, Anca Claudia

2015-01-01

Highlights: • We investigate the optimal policy mix for dealing with climate change. • We consider jointly mitigation, adaptation, and solar radiation management (SRM). • SRM can control temperature, but brings environmental side-effects. • SRM is not robust due to uncertainty in magnitude and persistency of side-effects. • Implementing SRM with wrong assumptions about side-effects largely decreases welfare. - Abstract: We investigate geoengineering as a possible substitute for mitigation and adaptation measures to address climate change. Relying on an integrated assessment model, we distinguish between the effects of solar radiation management (SRM) on atmospheric temperature levels and its side-effects on the environment. The optimal climate portfolio is a mix of mitigation, adaptation, and SRM. When accounting for uncertainty in the magnitude of SRM side-effects and their persistency over time, we show that the SRM option lacks robustness. We then analyse the welfare consequences of basing the SRM decision on wrong assumptions about its side-effects, and show that total output losses are considerable and increase with the error horizon. This reinforces the need to balance the policy portfolio in favour of mitigation

Photoluminescence and photoluminescence excitation studies in 80 MeV Ni ion irradiated MOCVD grown GaN

Energy Technology Data Exchange (ETDEWEB)

Devaraju, G. [School of Physics, University of Hyderabad, Central University P.O., Hyderabad 500 046 (India); Pathak, A.P., E-mail: appsp@uohyd.ernet.in [School of Physics, University of Hyderabad, Central University P.O., Hyderabad 500 046 (India); Srinivasa Rao, N.; Saikiran, V. [School of Physics, University of Hyderabad, Central University P.O., Hyderabad 500 046 (India); Enrichi, Francesco [Coordinamento Interuniversitario Veneto per le Nanotecnologie (CIVEN), via delle Industrie 5, Marghera, I-30175Venice (Italy); Trave, Enrico [Dipartimento di Chimica Fisica, Universita Ca' Foscari Venezia, Dorsoduro 2137, I-30123 Venice (Italy)

2011-09-01

Highlights: {yields} MOCVD grown GaN samples are irradiated with 80 MeV Ni ions at room temperature. {yields} PL and PLE studies have been carried out for band to band, BL and YL emissions. {yields} Ni ions irradiated GaN shows BL band at 450 nm besides YL band. {yields} Radiation annealed Ga vacancies have quenching effect on YL intensity. {yields} We speculated that BL and YL are associated with N and Ga vacancies, respectively. - Abstract: We report damage creation and annihilation under energetic ion bombardment at a fixed fluence. MOCVD grown GaN thin films were irradiated with 80 MeV Ni ions at a fluence of 1 x 10{sup 13} ions/cm{sup 2}. Irradiated GaN thin films were subjected to rapid thermal annealing for 60 s in nitrogen atmosphere to anneal out the defects. The effects of defects on luminescence were explored with photoluminescence measurements. Room temperature photoluminescence spectra from pristine sample revealed presence of band to band transition besides unwanted yellow luminescence. Irradiated GaN does not show any band to band transition but there is a strong peak at 450 nm which is attributed to ion induced defect blue luminescence. However, irradiated and subsequently annealed samples show improved band to band transitions and a significant decrease in yellow luminescence intensity due to annihilation of defects which were created during irradiation. Irradiation induced effects on yellow and blue emissions are discussed.

Ionic conductivity in irradiated KCL; Conductiviad ionica de KCL irradiado

Energy Technology Data Exchange (ETDEWEB)

Vignolo Rubio, J

1979-07-01

The ionic conductivity of X and gamma irradiated KCL single crystals has been studied between room temperature and 600 degree centigree. the radiation induced damage resulting in a decrease of the conductivity heals by thermal annealing in two steps which are at about 350 and 550 degree centigree respectively. It has been found that the radiation induced colour centres are not involved in the observed decrease of the ionic conductivity. However. It has been observed that the effects of quenching and plastic deformation on the conductivity of the samples are very similar to the effect induced by irradiation. It is suggested that, samples radiation induced dislocation loops might cause the ionic conductivity decrease observed in irradiated samples. (Author)

Preservation of avocados (var. Fuerte) by heat and irradiation combined treatment

International Nuclear Information System (INIS)

Karmelic, J.; Rubio, T.; Urbina, Y.M.C.

1983-01-01

The high national production of avocados expected for the next years asks for the opening of new markets to be reached by ship. For this reason, it is necessary to increase the shelf-life of avocados for a period of 40 days at least. Therefore, the effect of combined treatment: mild heat (46 0 C, 20 min) and low radiation doses (25, 50, 100 Gy), in avocados is studied. Additional parameters considered in this study are: wrapping with PVC film, storage temperature (7 0 C and room temperature), two different degrees of ripening. Best results are obtained with the lowest dose (25 Gy) and low degree of ripening of wrapped avocados, stored at 7 0 C. After 40 days, 98,6% of the avocados were well preserved and 85,5% after 50 days. When compared with non irradiated samples, avocados irradiated with 25 Gy show 25% and 34% higher undamaged percentage after 40 and 50 days of storage; respectively. A negative effect is obtained when irradiation is applied to avocados with a high degree of ripening. Room temperature is not suitable for a long storage period of avocados. (Author)

Electrical properties of as-grown and proton-irradiated high purity silicon

Energy Technology Data Exchange (ETDEWEB)

Krupka, Jerzy, E-mail: krupka@imio.pw.edu.pl [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Karcz, Waldemar [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Kamiński, Paweł [Institute of Electronic Materials Technology, Wólczyńska 13, 301-919 Warsaw (Poland); Jensen, Leif [Topsil Semiconductor Materials A/S, Siliciumvej 1, DK-3600 Frederikssund (Denmark)

2016-08-01

The complex permittivity of as-grown and proton-irradiated samples of high purity silicon obtained by the floating zone method was measured as a function of temperature at a few frequencies in microwave spectrum by employing the quasi TE{sub 011} and whispering gallery modes excited in the samples under test. The resistivity of the samples was determined from the measured imaginary part of the permittivity. The resistivity was additionally measured at RF frequencies employing capacitive spectroscopy as well as in a standard direct current experiment. The sample of as-grown material had the resistivity of ∼85 kΩ cm at room temperature. The sample irradiated with 23-MeV protons had the resistivity of ∼500 kΩ cm at 295 K and its behavior was typical of the intrinsic material at room and at elevated temperatures. For the irradiated sample, the extrinsic conductivity region is missing and at temperatures below 250 K hopping conductivity occurs. Thermal cycle hysteresis of the resistivity for the sample of as-grown material is observed. After heating and subsequent cooling of the sample, its resistivity decreases and then slowly (∼50 h) returns to the initial value.

Magnetic properties of a stainless steel irradiated with 6 MeV Xe ions

Science.gov (United States)

Xu, Chaoliang; Liu, Xiangbing; Qian, Wangjie; Li, Yuanfei

2017-11-01

Specimens of austenitic stainless steel were irradiated with 6 MeV Xe ions at room temperature to 2, 7, 15 and 25 dpa. The vibrating sample magnetometer (VSM), grazing incidence X-ray diffraction (GIXRD) and positron annihilation lifetime spectroscopy (PLS) were carried out to analysis the magnetic properties and microstructural variations. The magnetic hysteresis loops indicated that higher irradiation damage causes more significant magnetization phenomenon. The equivalent saturated magnetization Mes and coercive force Hc were obtained from magnetic hysteresis loops. It is indicated that the Mes increases with irradiation damage. While Hc increases first to 2 dpa and then decreases continuously with irradiation damage. The different contributions of irradiation defects and ferrite precipitates on Mes and Hc can explain these phenomena.

Nutritional aspects of irradiated mangoes

International Nuclear Information System (INIS)

Singh, H.

1990-06-01

Mangoes, like most other fruits, constitute a small but very important part of human diet in tropical countries. Their carbohydrate content is a source of energy; however, their main importance is as a rich source of vitamins, particularly vitamins A and C. Increasing the shelf life of mangoes is desirable, since on ripening they become highly perishable and have a very short shelf life. Low-dose irradiation is considered to be a good method for extending their shelf life. This literature review examines the effect of radiation processing on the nutrients in mangoes. In general, irradiation has little effect on the main nutrients, vitamin C, carotenoids and carbohydrates. There is a significant loss of vitamin C only in a few varieties of mangoes, while in the others the vitamin C level is unaffected. The extension of shelf life also depends on the storage conditions, particularly temperature. While low-temperature storage followed by ripening at room temperature leads to high vitamin C levels, it reduces the carotenoid levels in some varieties. Thus, the storage and the ripening temperatures should be optimized for each variety to obtain the maximum benefit of irradiation. Long-term, multi-generation rat feeding studies to assess the wholesomeness of irradiated mangoes have shown no adverse effects

Bulk and interface defects in electron irradiated InP

International Nuclear Information System (INIS)

Peng Chen; Sun Heng-hui

1989-01-01

Systematic studies on the structure of defects in InP caused by electron irradiation are conducted based on experimental measurements and theoretical calculations. The rates of introduction and annealing-out temperatures of In and P vancancies are estimated using proper theoretical models. These calculations reveal that after room temperature irradiation only complexes may exist. It is also supported by our experimental data that the sum of introducing rates of three detected levels are less than the theoretical value calculated for single vacancies. According to our equation on the relation between interface states and DLTS signal and from the results of computer calculation we believe that the broad peak appearing in the DLTS diagram before irradiation is related to interface states. Its disappearance after electron irradiation suggests the reduction of interface states; this is further confirmed by the reduction of surface recombination rate derived from the results of surface photovoltage measurement

Lactose and sucrose aqueous solutions for high-dose dosimetry with 10-MeV electron beam irradiation

International Nuclear Information System (INIS)

Amraei, R.; Kheirkhah, M.; Raisali, G.

2012-01-01

In the present study, dosimetric characterisation of aqueous solutions of lactose and sucrose was analysed by UV spectrometry following irradiation using 10-MeV electron beam at doses between 0.5 and 10.5 kGy. As a dosimetric index, absorbance is selected at 256 and 264 nm for lactose and sucrose aqueous solutions, respectively. The intensity of absorbance for irradiated solutions depends on the pre-irradiation concentration of lactose and sucrose. The post-irradiation stability of both solutions was investigated at room temperature for a measurement period of 22 d. (authors)

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

NARCIS (Netherlands)

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

2014-01-01

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

Preparation of PbSe nanoparticles by electron beam irradiation

Indian Academy of Sciences (India)

A novel method has been developed by electron beam irradiation to prepare PbSe nanoparticles. 2 MeV 10mA GJ-2-II electronic accelerator was used as radiation source. Nanocrystalline PbSe was prepared rapidly at room temperature under atmospheric pressure without any kind of toxic reagents. The structure and ...

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

Energy Technology Data Exchange (ETDEWEB)

Sagastibelza Chivite, F

1980-07-01

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

A Green Platform for Preparation of the Well-Defined Polyacrylonitrile: 60Co γ-ray Irradiation-Initiated RAFT Polymerization at Room Temperature

Directory of Open Access Journals (Sweden)

Shuangshuang Zhang

2017-01-01

Full Text Available 60Co γ-ray irradiation-initiated reversible addition–fragmentation chain transfer (RAFT polymerization at room temperature with 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN as the chain transfer agent was first applied to acrylonitrile (AN polymerization, providing a “green” platform for preparing polyacrylonitrile (PAN-based carbon fibers using an environment-friendly energy source. Various effects of dose rate, molar ratio of the monomer to the chain transfer agent, monomer concentration and reaction time on the AN polymerization behaviors were performed to improve the controllability of molecular the weight and molecular weight distribution of the obtained PAN. The feature of the controlled polymerization was proven by the first-order kinetics, linear increase of the molecular weight with the monomer conversion and a successful chain-extension experiment. The molecular weight and molecular weight distribution of PAN were characterized by size exclusion chromatography (SEC. 1H NMR and Matrix assisted laser desorption ionization/time of flight mass spectra (MALDI-TOF-MS confirmed the chain-end functionality of PAN, which also was supported by the successful chain-extension experiments of original PANs with acrylonitrile and styrene as the second monomers respectively.

Climate Change: Science and Policy Implications

National Research Council Canada - National Science Library

Leggett, Jane A

2007-01-01

.... Although natural forces such as solar irradiance and volcanoes contribute to variability, scientists cannot explain the climate changes of the past few decades without including the effects of elevated greenhouse gas (GHG...

Influence of temperature histories during reactor startup periods on microstructural evolution and mechanical properties of austenitic stainless steel irradiated with neutrons

Energy Technology Data Exchange (ETDEWEB)

Kasahara, Shigeki, E-mail: kasahara.shigeki@jaea.go.jp [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kitsunai, Yuji [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Chimi, Yasuhiro [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chatani, Kazuhiro; Koshiishi, Masato [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Nishiyama, Yutaka [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

2016-11-15

This paper addresses influence of two different temperature profiles during startup periods in the Japan Materials Testing Reactor and a boiling water reactor upon microstructural evolution and mechanical properties of austenitic stainless steel irradiated with neutrons to about 1 dpa and 3 dpa. One of the temperature profiles was that the specimens experienced neutron irradiation in both reactors, under which the irradiation temperature transiently increased to 290 °C from room temperature with increasing reactor power during reactor startup periods. Another was that the specimens were pre-heated to about 150 °C prior to the irradiation to suppress the transient temperature increase. Tensile tests at 290 °C and Vickers hardness tests at room temperature were carried out, and their microstructures were observed by FEG-TEM. Difference of the temperature profiles was observed obviously in interstitial cluster formation, in particular, growth of Frank loops. Although influence of neutron irradiation involving transient temperature increase to 290 °C from room temperature on the yield strength and the Vickers hardness is buried in the trend curves of existing data, the influence was also found certainly in increment of in yield strength, existence of modest yield drop, and loss of strain hardening capacity and ductility. As a result, Frank loops, which were observed in austenitic stainless steel irradiated at doses of 1 dpa or more, seemed to have important implications regarding the interpretation of not irradiation hardening, but deformation of the austenitic stainless steel.

Thereby the data stream is guaranteed. What you should look at the server room cooling; Damit der Datenfluss gewaehrleistet ist. Worauf man bei der Kuehlung von Serverraeumen achten sollte

Energy Technology Data Exchange (ETDEWEB)

Gaigalat, Jens [Daikin Airconditioning Germany GmbH, Muenchen (Germany)

2011-04-15

Without information technology and communication technology the daily operations do not work in a company. Server rooms and computer rooms are thermally high loaded rooms in a company. Therefore the data security includes air conditioning because the trouble-free operation of EDP devices requires an optimal climate control of the rooms.

Effect of composition and. gamma. -irradiation on crystal lattice spacing of lead sulphide

Energy Technology Data Exchange (ETDEWEB)

Indenbaum, G V; Novikova, S F; Vanyukov, A V; Dvorkin, Yu V [Moskovskij Inst. Stali i Splavov (USSR)

1981-02-01

Value of crystal lattice spacing of lead sulphide after annealing and quenching at temperatures of 600, 700 and 800 deg C are found for the both boundaries of homogeneity region with error of 5x10/sup -5/A. The effect of ..gamma.. irradiation with quanta energy of 1.25 MeV from /sup 60/Co source (10/sup 4/, 10/sup 5/ and 10/sup 6/ G/kg) on crystal lattice spacing of lead sulphide preliminary saturated with sulphur or lead at 600 deg C, is studied. It is established that lattice spacing of lead sulphide depends on material prehistory and decreases at room temperature after quenching and ..gamma..-irradiation. Effect of natural ageing of lead sulphide is explained by the decomposition of nonstechiometric solid solution, supersaturated with components, at room temperature.

Thermal stability of low dose Ga+ ion irradiated spin valves

International Nuclear Information System (INIS)

Qi Xianjin; Wang Yingang; Zhou Guanghong; Li Ziquan

2009-01-01

The thermal stability of low dose Ga + ion irradiated spin valves has been investigated and compared with that of the as-prepared ones. The dependences of exchange field, measured using vibrating sample magnetometer at room temperature, on magnetic field sweep rate and time spent at negative saturation of the pinned ferromagnetic layer, and training effect were explored. The training effect is observed on both the irradiated spin valves and the as-prepared ones. The magnetic field sweep rate dependence of the exchange bias field of the irradiated spin valves is nearly the same as that of the as-prepared ones. For the as-prepared structure thermal activation has been observed, which showed that holding the irradiated structure at negative saturation of the pinned ferromagnetic layer for up to 28 hours results in no change in the exchange field. The results indicate that the thermal stability of the ion irradiated spin valves is the same as or even better than the as-prepared ones.

Development of an apparatus for measuring the thermal conductivity of irradiated or non-irradiated graphite; Realisation d'un appareil de mesure de la conductibilite thermique du graphite irradie ou non irradie

Energy Technology Data Exchange (ETDEWEB)

Bocquet, M; Micaud, G

1962-07-01

An apparatus was developed for measuring the thermal conductivity coefficient K of irradiated or non-irradiated graphite. The measurement of K at around room temperature with an accuracy of about 6% is possible. The study specimen is placed in a vacuum between a hot and a cold source which create a temperature gradient {delta}{theta}/ {delta}x in the steady state. The amount of heat transferred, Q, is deduced from the electrical power dissipated at the hot source, after allowing for heat losses. The thermal conductivity coefficient is defined as: K = Q/S. {delta}x/{delta}{theta}, S being the cross section of the sample. Systematic studies have made it possible to determine the mean values of the thermal conductivity. (authors) [French] Un appareil de mesure du coefficient de conductibilite thermique K du graphite irradie ou non irradie a ete realise. Utilisant le principe du transfert de chaleur, il permet de mesurer K au voisinage de la temperature ambiante avec une precision de 6 pour cent environ. L'echantillon de graphite etudie est place sous vide entre une source chaude et une source froide qui creent en regime permanent un gradient de temperature {delta}{theta}/{delta}x La quantite de chaleur transferee Q est deduite de la puissance electrique dissipee dans la source chaude en deduisant les pertes thermiques. Le coefficient de conductibilite thermique est defini par: K = Q/S. {delta}x/{delta}{theta} S designant la section de l'echantillon. Des etudes systematiques ont permis de determiner pour differents graphites non irradies les valeurs moyennes des coefficients de conductibilite thermique. Ces etudes ont mis en evidence pour un type de graphite donne, l'influence de la densite apparente sur le coefficient de conductibilite thermique. A partir de mesures effectuees sur des echantillons de graphite irradies preleves par carottage dans les empilements des reacteurs a moderateur de graphite les variations du rapport K0/Ki en fonction de la dose et de la

Study on the Application of Cool Paintings for the Passive Cooling of Existing Buildings in Mediterranean Climates

Directory of Open Access Journals (Sweden)

V. Costanzo

2013-01-01

Full Text Available Building roofs play a very important role in the energy balance of buildings, especially in summer, when they are hit by a rather high solar irradiance. Depending on the type of finishing layer, roofs can absorb a great amount of heat and reach quite high temperatures on their outermost surface, which determines significant room overheating. However, the use of highly reflectivecool materials can help to maintain low outer surface temperatures; this practice may improve indoor thermal comfort and reduce the cooling energy need during the hot season. This technology is currently well known and widely used in the USA, whilereceiving increasing attention in Europe. In order to investigate the effectiveness of cool roofs as a passive strategy for passive cooling in moderately hot climates, this paper presents the numerical results of a case study based on the dynamic thermal analysis of an existing office building in Catania (southern Italy, Mediterranean area. The results show how the application of a cool paint on the roof can enhance the thermal comfort of the occupants by reducing the operative temperatures of the rooms and to reduce the overall energy needs of the building for space heating and cooling.

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

International Nuclear Information System (INIS)

Al-Bachir, M.

2002-09-01

Seeds of ansium 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, dissolved organic and inorganic solids in extract and sensory properties of extract were evaluated after 0, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the aerobic plate counts. Immediately after irradiation, the dissolved organic solids in extract of irradiated seeds were higher than those of non-irradiated ones. The dissolved organic matter in extract of irradiated and un-irradiated ansium seeds increased. After 6 and 12 months of storage. There were no significant differences in dissolved solids between the extract of irradiated and non-irradiated ansium seeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of ansium seed extract tested immediately after irradiation; however, after 12 months of storage, no significant differences (P>0.05) were found in color, taste or odor between extract of irradiated and unirradiated ansium seeds. (author)

Accelerating Energy Efficiency Improvements in Room Air Conditioners in India: Potential, Costs-Benefits, and Policies

OpenAIRE

Abhyankar, N; Shah, N; Park, WY; Phadke, AA

2017-01-01

Rising incomes, increasing urbanization, and large cooling demand prompted by India’s hot, humid climate are driving increasing uptake of room air conditioners (ACs). Air conditioning already accounts for 40-60% of summer peak load in large Indian cities such as Delhi and is on track to contribute 140 gigawatts (GW) ( 30%) to peak demand in 2030. India’s standards and labeling policies improved the market average efficiency of room ACs by about 35% between 2006 and 2016 (3% per year) even as ...

Fracture toughness of ferritic alloys irradiated at FFTF

International Nuclear Information System (INIS)

Huang, F.H.

1986-05-01

Ferritic compact tension specimens loaded in the Material Open Test Assembly (MOTA) for irradiation during FFTF Cycle 4 were tested at temperatures ranging from room temperature to 428/degree/C. The electrical potential single specimen method was used to measure the fracture toughness of the specimens. Results showed that the fracture toughness of both HT-9 and 9Cr-1Mo decreases with increasing test temperature and that the toughness of HT-9 was about 30% higher than that of 9Cr-1Mo. In addition, increasing irradiation temperature resulted in an increase in tearing modulus for both alloys. 4 refs., 5 figs., 1 tab

Study of effect of composition, irradiation and quenching on ionic ...

Indian Academy of Sciences (India)

The electrolyte samples are also quenched at liquid nitrogen temperature and conductivity measurements are carried out. The ionic conductivity at room temperature exhibits a characteristic peak for the composition, = 46. Electron beam irradiation results in an increase in conductivity for all compositions by a factor of 2–3.

Deuterium trapping in liquid lithium irradiated by deuterium plasma

International Nuclear Information System (INIS)

Pisarev, A.; Moshkunov, K.; Vizgalov, I.; Gasparyan, Yu.

2013-01-01

Liquid lithium was irradiated by deuterium plasma to a low fluence of 10 22 –10 23 D/m 2 , cooled down to room temperature, and then slowly heated. The temperature and release rate were measured during heating. Two plateaus on the temperature–time dependence were observed at 180 °C and 660 °C. The first one corresponds to melting of Li and the second one – either to melting or to decomposition of solid LiD. Features of deuterium release in TDS were interpreted in terms of decomposition of lithium deuterides formed during plasma irradiation

Determination dimension and technical specification of the cylindrical pneumatics for the tote movement on multipurpose the gamma irradiator BATAN

International Nuclear Information System (INIS)

Muhammad Subhan; Ari Satmoko

2016-01-01

BATAN develops irradiator gamma category IV in cooperation with IZOTOP (Hungary). Transportation technology products that will be developed uses rail system to pool. Products that will be irradiated are put into tote then placed on the transportation rail, when tote has been in irradiated room tote enters into irradiated rack. The movement of the tote during on irradiated rack will be driven by the pneumatic system. Based on data from Isotop there are 14 cylindrical pneumatics that are in the irradiated room. Through the results analysis then used double acting cylinder type from the Festo pneumatics catalog. Through the results calculation that the force used on all types of cylinders for movement tote still much smaller than of force bent permitted. Beside that there are 4 group a pneumatic have common specifications they are group one cylindrical C1, C3, C12 and C14 they are group two cylindrical C2, C4, C11, and C13 they are group three cylindrical C7, C9, C15 and C17 they are group four cylindrical C10 and C17. (author)

Short Communication on "In-situ TEM ion irradiation investigations on U3Si2 at LWR temperatures"

Science.gov (United States)

Miao, Yinbin; Harp, Jason; Mo, Kun; Bhattacharya, Sumit; Baldo, Peter; Yacout, Abdellatif M.

2017-02-01

The radiation-induced amorphization of U3Si2 was investigated by in-situ transmission electron microscopy using 1 MeV Kr ion irradiation. Both arc-melted and sintered U3Si2 specimens were irradiated at room temperature to confirm the similarity in their responses to radiation. The sintered specimens were then irradiated at 350 °C and 550 °C up to 7.2 × 1015 ions/cm2 to examine their amorphization behavior under light water reactor (LWR) conditions. U3Si2 remains crystalline under irradiation at LWR temperatures. Oxidation of the material was observed at high irradiation doses.

THE TOTAL SOLAR IRRADIANCE CLIMATE DATA RECORD

Energy Technology Data Exchange (ETDEWEB)

Dewitte, Steven; Nevens, Stijn [Royal Meteorological Institute of Belgium, Ringlaan 3, B-1180 Brussels (Belgium)

2016-10-10

We present the composite measurements of total solar irradiance (TSI) as measured by an ensemble of space instruments. The measurements of the individual instruments are put on a common absolute scale, and their quality is assessed by intercomparison. The composite time series is the average of all available measurements. From 1984 April to the present the TSI shows a variation in phase with the 11 yr solar cycle and no significant changes of the quiet-Sun level in between the three covered solar minima.

Changes in content and composition of sugar in molasses caused by gamma-irradiation

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Sato, Tomotaro

1980-01-01

The sugar contents in undiluted molasses were found to be stable on γ-irradiation. The contents of total sugar and direct reducing sugar in cane molasses were completely unaffected by irradiation with doses of less than 3 Mrad. The reduction of total sugar content in beet molasses was 2% at 3 Mrad. On the other hand, in the molasses diluted with water, sugar contents decreased with the dose. Sucrose in molasses was degraded by irradiation, and subsequently glucose and fructose were formed. Raffinose in beet molasses was also degraded by irradiation, but galactose could not be detected. The irradiation temperature ranging from room temperature to 61 0 C, was hardly responsible for the change of sugar contents, but the changes in sugar caused by irradiation were enhanced at pHs of less than 4 and with an excess of oxygen. (author)

Changes in content and composition of sugar in molasses caused by gamma-irradiation

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H; Sato, T

1980-01-01

The sugar contents in undiluted molasses were found to be stable on ..gamma..-irradiation. The contents of total sugar and direct reducing sugar in cane molasses were completely unaffected by irradiation with doses of less than 3 Mrad. The reduction of total sugar content in beet molasses was 2% at 3 Mrad. On the other hand, in the molasses diluted with water, sugar contents decreased with the dose. Sucrose in molasses was degraded by irradiation, and subsequently glucose and fructose were formed. Raffinose in beet molasses was also degraded by irradiation, but galactose could not be detected. The irradiation temperature ranging from room temperature to 61/sup 0/C, was hardly responsible for the change of sugar contents, but the changes in sugar caused by irradiation were enhanced at pHs of less than 4 and with an excess of oxygen.

Changes in content and composition of sugar in molasses caused by gamma-irradiation

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H; Sato, T [Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment

1980-08-01

The sugar contents in undiluted molasses were found to be stable on ..gamma..-irradiation. The contents of total sugar and direct reducing sugar in cane molasses were completely unaffected by irradiation with doses of less than 3 Mrad. The reduction of total sugar content in beet molasses was 2% at 3 Mrad. On the other hand, in the molasses diluted with water, sugar contents decreased with the dose. Sucrose in molasses was degraded by irradiation, and subsequently glucose and fructose were formed. Raffinose in beet molasses was also degraded by irradiation, but galactose could not be detected. The irradiation temperature ranging from room temperature to 61/sup 0/C, was hardly responsible for the change of sugar contents, but the changes in sugar caused by irradiation were enhanced at pHs of less than 4 and with an excess of oxygen.

Utilization of irradiation on food preservation

International Nuclear Information System (INIS)

Cho, Han Ok; Byun, Myung Woo; Kwon, Joong Ho; Kim, Suk Won; Yang, Jae Sung; Cha, Bo Sook; Park, Ki Bum

1987-12-01

The present project was intended to ascertain the efficacy of irradiation both in the decontamination and storeability of mixed condiments for convenience food and in the long-term preservation of a Kimchi. Based upon the preliminary studies, irradiated sample with doses at 1-3 kGy were evaluated during the storage for 30 days at 10 deg C from the points of view of microbiological (total aerobic bacteria, lactic acid bacteria, yeasts and molds, and coliforms), physicochemical (pH, total acidity, volatile acid, reducing sugar, ascorbic acid, and texture) and organoleptic qualities. Besides, the combined effect of irradiation with heating on the storeability was investigated for five species of the lactic acid bacteria associated with the Kimchi fermentation. Under the room temperature storage conditions, physicochemical qualities of the irradiated samples were evaluated by determining pH, rancidity (TBA number), proximate composition, amino nitrogen, amino acid, and color changes. In the overall evaluation of sensory quality for the irradiated Kimchi, the nonirradiated control group was inedible after 15 days of storage, whereas 2-3 kGy irradiation could prolong the storage-life of the Kimchi over 2 times compared with the nonirradiated control, showing the good sensory quality even after 30 days of storage. In comparative effects of irradiation and ethylene oxide both treatments affected more or less rancidity, color, and amino acid content, but less than 10 kGy irradiation was shown to be safer than ethylene oxide fumigation. Form the foregoing results, it can be concluded that if a selective method could be applied to the radiation sterilization of minor ingredients capable of mainly contaminating the mixed condiments, even lower doses of irradiation should be effective for the microbial control. (Author)

Room Acoustics

Science.gov (United States)

Kuttruff, Heinrich; Mommertz, Eckard

The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

Control of the Environment in the Operating Room.

Science.gov (United States)

Katz, Jonathan D

2017-10-01

There is a direct relationship between the quality of the environment of a workplace and the productivity and efficiency of the work accomplished. Components such as temperature, humidity, ventilation, drafts, lighting, and noise each contribute to the quality of the overall environment and the sense of well-being of those who work there.The modern operating room is a unique workplace with specific, and frequently conflicting, environmental requirements for each of the inhabitants. Even minor disturbances in the internal environment of the operating room can have serious ramifications on the comfort, effectiveness, and safety of each of the inhabitants. A cool, well-ventilated, and dry climate is optimal for many members of the surgical team. Any significant deviation from these objectives raises the risk of decreased efficiency and productivity and adverse surgical outcomes. A warmer, more humid, and quieter environment is necessary for the patient. If these requirements are not met, the risk of surgical morbidity and mortality is increased. An important task for the surgical team is to find the correct balance between these 2 opposed requirements. Several of the components of the operating room environment, especially room temperature and airflow patterns, are easily manipulated by the members of the surgical team. In the following discussion, we will examine these elements to better understand the clinical ramifications of adjustments and accommodations that are frequently made to meet the requirements of both the surgical staff and the patient.

Effects of High-Energy Proton-Beam Irradiation on the Magnetic Properties of ZnO Nanorods

Energy Technology Data Exchange (ETDEWEB)

Park, Jun Kue; Kwon, Hyeok-Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

There are still many problem for the application due to its unstable magnetism state and too small magnetization values. Here we investigate magnetic properties of ZnO nanorods after high-energy proton-beam irradiation. Electron spin resonance (ESR) measurement on temperature was made to identify intrinsic or extrinsic defects as well as to observe magnetic ordering after irradiation. Understanding the effects of proton beam irradiation on magnetic behavior may help to shed light on the mechanism responsible for the magnetic ordering in this material. We have investigated proton-beam irradiation effects on the magnetic properties of ZnO nanorods. After irradiation a broad ESR line is observed, indicating emergence of ferromagnetic ordering up to room temperature. In M-H curve, stronger coercive field is observed after irradiation.

Climate variations and the enhanced greenhouse effect

Energy Technology Data Exchange (ETDEWEB)

Karlen, W. [Stockholm Univ. (Sweden). Dept. of Physical Geography

1998-06-01

Changes in the size of glaciers, in the altitude of the alpine tree-limit, and variation in the width of tree-rings during the Holocene clearly indicate that the average Scandinavian summer temperature has fluctuated. During warm periods it has been about 2 deg C warmer than at present; during cold periods it has been almost as cold as it was during the coldest decades of the previous centuries. Superimposed on these long-term variations, which have lasted from 100 to 200 years, are short fluctuations in temperature. The Scandinavian chronology, which is based on glacier and alpine tree-limit fluctuations as well as on dendrochronology, is well correlated with the changes in climate, which studies of ice cores from central Greenland have revealed. It is therefore believed that the Scandinavian climate chronology depicts conditions typical of a large area. The Scandinavian record is compared with data concerning solar irradiation variations estimated as {sup 14}C anomalies obtained from tree-rings. A correlation between major changes in climate and variations in solar irradiation points to a solar forcing of the climate. This means that there is no evidence of a human influence on climate so far Special issue. Research for mountain area development: Europe. 64 refs, 3 figs

A versatile program for the calculation of linear accelerator room shielding.

Science.gov (United States)

Hassan, Zeinab El-Taher; Farag, Nehad M; Elshemey, Wael M

2018-03-22

This work aims at designing a computer program to calculate the necessary amount of shielding for a given or proposed linear accelerator room design in radiotherapy. The program (Shield Calculation in Radiotherapy, SCR) has been developed using Microsoft Visual Basic. It applies the treatment room shielding calculations of NCRP report no. 151 to calculate proper shielding thicknesses for a given linear accelerator treatment room design. The program is composed of six main user-friendly interfaces. The first enables the user to upload their choice of treatment room design and to measure the distances required for shielding calculations. The second interface enables the user to calculate the primary barrier thickness in case of three-dimensional conventional radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT) and total body irradiation (TBI). The third interface calculates the required secondary barrier thickness due to both scattered and leakage radiation. The fourth and fifth interfaces provide a means to calculate the photon dose equivalent for low and high energy radiation, respectively, in door and maze areas. The sixth interface enables the user to calculate the skyshine radiation for photons and neutrons. The SCR program has been successfully validated, precisely reproducing all of the calculated examples presented in NCRP report no. 151 in a simple and fast manner. Moreover, it easily performed the same calculations for a test design that was also calculated manually, and produced the same results. The program includes a new and important feature that is the ability to calculate required treatment room thickness in case of IMRT and TBI. It is characterised by simplicity, precision, data saving, printing and retrieval, in addition to providing a means for uploading and testing any proposed treatment room shielding design. The SCR program provides comprehensive, simple, fast and accurate room shielding calculations in radiotherapy.

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.

Simulation study on the operating characteristics of the heat pipe for combined evaporative cooling of computer room air-conditioning system

International Nuclear Information System (INIS)

Han, Zongwei; Zhang, Yanqing; Meng, Xin; Liu, Qiankun; Li, Weiliang; Han, Yu; Zhang, Yanhong

2016-01-01

In order to improve the energy efficiency of air conditioning systems in computer rooms, this paper proposed a new concept of integrating evaporative cooling air-conditioning system with heat pipes. Based on a computer room in Shenyang, China, a mathematical model was built to perform transient simulations of the new system. The annual dynamical performance of the new system was then compared with a typical conventional computer room air-conditioning system. The result showed that the new integrated air-conditioning system had better energy efficiency, i.e. 31.31% reduction in energy consumption and 29.49% increase in COP (coefficient of performance), due to the adoption of evaporative condenser and the separate type heat pipe technology. Further study also revealed that the incorporated heat pipes enabled a 36.88% of decrease in the operation duration of the vapor compressor, and a 53.86% of reduction for the activation times of the compressor, which could lead to a longer lifespan of the compressor. The new integrated evaporative cooling air-conditioning system was also tested in different climate regions. It showed that the energy saving of the new system was greatly affected by climate, and it had the best effect in cold and dry regions like Shenyang with up to 31.31% energy saving. In some warm and humid climate regions like Guangzhou, the energy saving could be achieved up to 13.66%. - Highlights: • A novel combined air-conditioning system of computer room is constructed. • The performance of the system and conventional system is simulated and compared. • The applicability of the system in different climate regions is investigated.

Point defects and magnetic properties of neutron irradiated MgO single crystal

Directory of Open Access Journals (Sweden)

Mengxiong Cao

2017-05-01

Full Text Available (100-oriented MgO single crystals were irradiated to introduce point defects with different neutron doses ranging from 1.0×1016 to 1.0×1020 cm-2. The point defect configurations were studied with X-ray diffuse scattering and UV-Vis absorption spectra. The isointensity profiles of X-ray diffuse scattering caused by the cubic and double-force point defects in MgO were theoretically calculated based on the Huang scattering theory. The magnetic properties at different temperature were measured with superconducting quantum interference device (SQUID. The reciprocal space mappings (RSMs of irradiated MgO revealed notable diffuse scattering. The UV-Vis spectra indicated the presence of O Frenkel defects in irradiated MgO. Neutron-irradiated MgO was diamagnetic at room temperature and became ferromagnetic at low temperature due to O Frenkel defects induced by neutron-irradiation.

Irradiation-induced creep in metallic nanolaminates characterized by In situ TEM pillar nanocompression

Energy Technology Data Exchange (ETDEWEB)

Dillon, Shen J., E-mail: sdillon@illinois.edu [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States); Bufford, Daniel C. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Jawaharram, Gowtham S.; Liu, Xuying; Lear, Calvin [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States); Hattar, Khalid [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Averback, Robert S. [Department of Materials Science and Engineering, University of Illinois Urbana-Champagin, Urbana, IL 61801 (United States)

2017-07-15

This work reports on irradiation-induced creep (IIC) measured on nanolaminate (Cu-W and Ni-Ag) and nanocrystalline alloys (Cu-W) at room temperature using a combination of heavy ion irradiation and nanopillar compression performed concurrently in situ in a transmission electron microscope. Appreciable IIC is observed in multilayers with 50 nm layer thicknesses at high stress, ≈½ the yield strength, but not in multilayers with only 5 nm layer thicknesses.

Oxalate molecule as the trap for gamma-irradiation energy in the amorphous aluminosilicate Al2(OH)6H4SiO4

International Nuclear Information System (INIS)

Nothig-Laslo, V.; Horvath, L.; Bilinski, H.

1990-01-01

Paramagnetic species which were the products of gamma irradiation at 77 K and at room temperature were studied by ESR spectroscopy in the amorphous aluminosilicate, Al2(OH)6H4SiO4, prepared in the presence and in the absence of oxalate ion. The aluminosilicate precipitated from the solution containing the oxalate ion in 10(-4) mol dm-3 concentration contained the oxalate only in trace amounts. When gamma-irradiated at 77 K and at room temperature, this compound gave the stable paramagnetic species represented by the single ESR line centered at g = 2.000. We ascribe this spectrum to the CO2- radical formed from the oxalate ion. The same aluminosilicate prepared in the absence of the oxalate either produced no stable paramagnetic product after gamma irradiation at room temperature or resulted in composite ESR spectra, indicating the presence of several paramagnetic species if irradiated at 77 K. Complex ESR spectra were transformed by heating to the stable paramagnetic centers which differed from the one obtained from oxalate ion. We conclude that in Al2(OH)6H4SiO4 oxalate acts as a trap for the gamma-radiation energy

The role of natural antibiotics in storage diseases resistance in irradiated tomato fruits

International Nuclear Information System (INIS)

Sharaway, N.S.M.

1981-01-01

Tomato (lycopersicum esculantum L.) is one of the most important vegetable crops in egypt. Fruit rot, mainly due to fungi, are essential obstacles facing the nowadays prejects plannings of the yield production and exportation. Tomato fruits, variety money maker at green mature exposed to acute gamma irradiation doses at 5, 10, 20, 30 and 100 K rad after inoculated with spore suspension of alternaria tenuis , the main casual organism of fruit rot of tomato and control without inoculation. The source of irradiation was cobalt 60. After irradiation , 50 tomato fruits were packed into exporting carton boxes and then were stored at room temperature

Dosimetric characteristics of ultraviolet and x-ray-irradiated KBr:Eu2+ thermoluminescence crystals

International Nuclear Information System (INIS)

Melendrez, R.; Perez-Salas, R.; Aceves, R.; Piters, T.M.; Barboza-Flores, M.

1996-01-01

Thermoluminescence (TL) characteristics of KBr:Eu 2+ (150 ppm) previously exposed to ultraviolet (UV) light (200 endash 300 nm) and x-ray radiation at room temperature have been determined. The TL glow curve of UV-irradiated samples is composed of six peaks located at 337, 384, 402, 435, 475, and 510 K. The TL glow curves of x-irradiated samples show mainly a TL peak around 384 K. The TL intensities of UV-irradiated (402 and 510 K glow peaks) and x-irradiated specimens present a linear dependence as a function of radiation dose as well as fading stability 300 s after irradiation. These results further enhance the possibilities of using europium-doped materials in nonionizing (actinic region) and ionizing radiation detection and dosimetry applications. copyright 1996 American Institute of Physics

Sterilization of Carriers by using Gamma Irradiation for Bio fertilizer Inoculum Production

International Nuclear Information System (INIS)

Tittabutr, Panlada; Teamtisong, Kamonluck; Pewlong, Wachiraporn; Teaumroong, Neuhg; Laoharojanaphand, Sirinart; Boonkerd, Nantakorn

2009-07-01

Full text: Gamma irradiation has been widely used in sterilization process, which leads to improvement in the quality of the products. In the case of bio fertilizer inoculum, the sterilized carrier is also needed for producing high quality bio fertilizer. This study aimed at determining the factors, such as carrier materials, moistures, and packing sizes including packaging materials that may affect the sterilization efficiency by using gamma irradiation. All carrier materials, peat and compost, could be efficiently sterilized by irradiation. The carriers that have moisture content lower than 20% could be sterilized by irradiation at 15 kGy, while carrier with 30% moisture content must be sterilized by irradiation at 25 kGy. Higher irradiation dose was also necessary for sterilization of bigger carrier packing sizes. For, packaging materials, polyethylene bag appeared most durable after gamma irradiation even at high doses. However, contaminants could be detected in irradiated carrier after storage at room temperature for two months. It was hypothesized that these contaminants are spore forming microorganisms, which resist gamma irradiation. This hypothesis, as well as the quality of bio fertilizer produced from irradiated carrier, will be further evaluated

Radiotherapy of lung cancer: Any room left for elective mediastinal irradiation in 2011?; Radiotherapie des cancers bronchiques: place de l'irradiation mediastinale prophylactique en 2011

Energy Technology Data Exchange (ETDEWEB)

Van Houtte, P.; Roelandts, M. [Departement de radiotherapie-oncologie, institut Jules-Bordet, 121, boulevard de Waterloo, 1000 Bruxelles (Belgium); Faculte de medecine, universite libre de Bruxelles, campus erasme, route de Lennik 808, 1070 Bruxelles (Belgium); Mornex, F. [Departement de radiotherapie-oncologie, centre hospitalier Lyon-Sud, chemin du Grand-Revoyet, 69310 Pierre-Benite (France); EA3738, universite Claude-Bernard Lyon-1, domaine Rockefeller, 8, avenue Rockefeller, 69373 Lyon cedex 08 (France)

2011-10-15

Traditionally, the target volumes of curative-intent radiotherapy for non-small cell lung cancer include all uninvolved mediastinal nodes. However, an improvement in tumour control requires an increase of the total dose to the macroscopic target volume. This is only achievable if the irradiation of the organs at risk is reduced, i.e. elective irradiation of the mediastinum is omitted. The available data suggest that elective mediastinal irradiation may be safely omitted, provided that an adequate staging procedure, including FDG PET-CT, has been performed. (authors)

Electrical characteristics of {sup 60}Co {gamma}-ray irradiated MIS Schottky diodes

Energy Technology Data Exchange (ETDEWEB)

Tataroglu, A. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)]. E-mail: ademt@gazi.edu.tr; Altindal, S. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)

2006-11-15

In order to interpret the effect of {sup 60}Co {gamma}-ray irradiation dose on the electrical characteristics of MIS Schottky diodes, they were stressed with a zero bias at 1 MHz in dark and room temperature during {gamma}-ray irradiation and the total dose range was 0-450 kGy. The effect of {gamma}-ray exposure on the electrical characteristics of MIS Schottky diodes has been investigated using C-V and G/{omega}-V measurements at room temperature. Experimental results show that {gamma}-ray irradiation induces a decrease in the barrier height {phi} {sub B} and series resistance R {sub s}, decreasing with increasing dose rate. Also, the acceptor concentration N {sub A} increases with increasing radiation dose. The C-V characteristics prove that there is a reaction for extra recombination centers in case of MIS Schottky diodes exposed to {gamma}-ray radiation. Furthermore, the density of interface states N {sub ss} by Hill-Coleman method increases with increasing radiation dose. Experimental results indicate that the interface-trap formation at high irradiation dose is reduced due to positive charge build-up in the Si/SiO{sub 2} interface (due to the trapping of holes) that reduces the flow rate of subsequent holes and protons from the bulk of the insulator to the Si/SiO{sub 2} interface.

Radical formation of irradiated α-alanine and N-acetyl alanine with heavy ion beams. Effects of the irradiation temperature

International Nuclear Information System (INIS)

Minegishi, Atsuko; Nagasaki, Jun; Mori, Wasuke; Amano, Chikara; Takagi, Shinji; Murakami, Takeshi; Kanai, Tatsuaki; Furusawa, Yoshiya; Iwata, Yoshiyuki

2003-01-01

The characteristics of irradiation with C290 MeV/u ion beams were investigated using X-band electron spin resonance (ESR) spectroscopy for a polycrystalline powder of L-α-alanine at from 77K to 310K. The formed main radicals at 190K∼310K were the deamino radical and the decarboxyl radical. Because of the first-derivative ESR, decarboxyl radical showed an expanded spectral width and a lower peak height because of its amino hydrogen and nitrogen than that of the same amount of deamino radical. The ESR of irradiated L-α-alanine predominantly indicates the spectrum of the deamino radical. On the irradiated, L-α-alanine at from 77K to 310K ESR showed 1:4:6:4:1 lines at 220K and at room temperature, which indicate that the methyl group of the radical was rotating. On the other hand, at 77K ESR the spectrum showed nearly 1:5:5:5:1 lines, like the teeth of a saw, on samples irradiated at 270K∼350K (range IV), and 1:4:6:4:1 lines for those irradiated at 180K∼260K (range II and III), respectively. It is considered that the radical conformation of the deamino radical is planar (most stable conformation) on an irradiated sample in range IV, and a pyramidal structure on the irradiated sample in ranges II and III. (author)

Biochemical changes in ginger after gamma irradiation

International Nuclear Information System (INIS)

Kausar, T.; Salahuddin; Pervaiz, K.; Niazi, A.H.K.

2001-01-01

Ginger (Zingiber officinate) was irradiated with gamma rays (0.1Kgy, 1.0Kgy). Biochemical changes during storage at room temperature (23-28 degree centigrade), in sand (23-28 degree centigrade) and at cold (8 degree centigrade) temperature were observed. Changes in starch, soluble protein, fixed oil and volatile oil contents showed that treatment of ginger at 0.1Kgy radiation level was most appropriate for storage upto 45 days

Effect of neutron irradiation on select MAX phases

International Nuclear Information System (INIS)

Tallman, Darin J.; Hoffman, Elizabeth N.; Caspi, El’ad N.; Garcia-Diaz, Brenda L.; Kohse, Gordon; Sindelar, Robert L.; Barsoum, Michel W.

2015-01-01

Herein we report on the effect of neutron irradiation – of up to 0.1 displacements per atom at 360(20) °C or 695(25) °C – on polycrystalline samples of Ti 3 AlC 2 , Ti 2 AlC, Ti 3 SiC 2 and Ti 2 AlN. Rietveld refinement of X-ray diffraction patterns of the irradiated samples showed irradiation-enhanced dissociation into TiC of the Ti 3 AlC 2 and Ti 3 SiC 2 phases, most prominently in the former. Ti 2 AlN also showed an increase in TiN content, as well as Ti 4 AlN 3 after irradiation. In contrast, Ti 2 AlC was quite stable under these irradiation conditions. Dislocation loops are seen to form in Ti 2 AlC and Ti 3 AlC 2 after irradiation at 360(20) °C. The room temperature electrical resistivity of all samples increased by an order of magnitude after irradiation at 360(20) °C, but only by 25% after 695(25) °C, providing evidence for the MAX phases’ dynamic recovery at temperatures as low at 695(25) °C. Based on these preliminary results, it appears that Ti 2 AlC and Ti 3 SiC 2 are the more promising materials for high-temperature nuclear applications

The Sun and the Earth's Climate

Directory of Open Access Journals (Sweden)

Haigh Joanna D.

2007-10-01

Full Text Available Variations in solar activity, at least as observed in numbers of sunspots, have been apparent since ancient times but to what extent solar variability may affect global climate has been far more controversial. The subject had been in and out of fashion for at least two centuries but the current need to distinguish between natural and anthropogenic causes of climate change has brought it again to the forefront of meteorological research. The absolute radiometers carried by satellites since the late 1970s have produced indisputable evidence that total solar irradiance varies systematically over the 11-year sunspot cycle, relegating to history the term “solar constant”, but it is difficult to explain how the apparent response to the Sun, seen in many climate records, can be brought about by these rather small changes in radiation. This article reviews some of the evidence for a solar influence on the lower atmosphere and discusses some of the mechanisms whereby the Sun may produce more significant impacts than might be surmised from a consideration only of variations in total solar irradiance.

Fungal DNA in hotel rooms in Europe and Asia--associations with latitude, precipitation, building data, room characteristics and hotel ranking.

Science.gov (United States)

Norbäck, Dan; Cai, Gui-Hong

2011-10-01

There is little information on the indoor environment in hotels. Analysis of fungal DNA by quantitative PCR (qPCR) is a new method which can detect general and specific sequences. Dust was collected through swab sampling of door frames in 69 hotel rooms in 20 countries in Europe and Asia (2007-2009). Five sequences were detected by qPCR: total fungal DNA, Aspergillus and Penicillium DNA (Asp/Pen DNA), Aspergillus versicolor (A. versicolor DNA), Stachybotrys chartarum (S. chartarum DNA) and Streptomyces spp. (Streptomyces DNA). Associations were analysed by multiple linear regression. Total fungal DNA (GM = 1.08 × 10(8) cell equivalents m(-2); GSD = 6.36) and Asp/Pen DNA (GM = 1.79 × 10(7) cell equivalents m(-2); GSD = 10.12) were detected in all rooms. A. versicolor DNA, S. chartarum DNA and Streptomyces DNA were detected in 84%, 28% and 47% of the samples. In total, 20% of the rooms had observed dampness/mould, and 30% had odour. Low latitude (range 1.5-64.2 degrees) was a predictor of Asp/Pen DNA. Seaside location, lack of mechanical ventilation, and dampness or mould were other predictors of total fungal DNA and Asp/Pen DNA. Hotel ranking (Trip Advisor) or self-rated quality of the interior of the hotel room was a predictor of total fungal DNA, A. versicolor DNA and Streptomyces DNA. Odour was a predictor of S. chartarum DNA. In conclusion, fungal DNA in swab samples from hotel rooms was related to latitude, seaside location, ventilation, visible dampness and indoor mould growth. Hotels in tropical areas may have 10-100 times higher levels of common moulds such as Aspergillus and Penicillium species, as compared to a temperate climate zone.

Flow patterns and thermal comfort in a room with panel, floor and wall heating

Energy Technology Data Exchange (ETDEWEB)

Myhren, Jonn Are; Holmberg, Sture [Fluid and Climate Technology, Department of Constructional Engineering and Design, KTH, School of Technology and Health, Marinens vaeg 30, SE-13640 Haninge-Stockholm (Sweden)

2008-07-01

Thermal comfort aspects in a room vary with different space heating methods. The main focus in this study was how different heating systems and their position affect the indoor climate in an exhaust-ventilated office under Swedish winter conditions. The heat emitters used were a high and a medium-high temperature radiator, a floor heating system and large wall heating surfaces at low temperature. Computational fluid dynamics (CFD) simulations were used to investigate possible cold draught problems, differences in vertical temperature gradients, air speed levels and energy consumption. Two office rooms with different ventilation systems and heating needs were evaluated. Both systems had high air exchange rates and cold infiltration air. The general conclusions from this study were that low temperature heating systems may improve indoor climate, giving lower air speeds and lower temperature differences in the room than a conventional high temperature radiator system. The disadvantage with low temperature systems is a weakness in counteracting cold down-flow from ventilation supply units. For that reason the location of heat emitters and the design of ventilation systems proved to be of particular importance. Measurements performed in a test chamber were used to validate the results from the CFD simulations. (author)

SEM analysis for irradiated materials

International Nuclear Information System (INIS)

Liu Xiaosong; Yao Liang

2008-06-01

A radiation-proof Scanning Electron Microscope (SEM) system is introduced. It has been widely used in various areas. For analyzing radioactive samples, normal SEM system needs lots of alterations. Based on KYKY-2800B SEM, the sample room, belt line, operating table and aerator were updated. New radiation-proof SEM system has used to analytic surface contaminated samples and RPV materials samples. An elementary means of SEM analysis for radioactive samples was studied, and this examination supported some available references for further irradiated fuel researches. (authors)

The dinoflagellate Akashiwo sanguinea will benefit from future climate change: The interactive effects of ocean acidification, warming and high irradiance on photophysiology and hemolytic activity.

Science.gov (United States)

Ou, Guanyong; Wang, Hong; Si, Ranran; Guan, Wanchun

2017-09-01

Due to global climate change, marine phytoplankton will likely experience low pH (ocean acidification), high temperatures and high irradiance in the future. Here, this work report the results of a batch culture experiment conducted to study the interactive effects of elevated CO 2 , increased temperature and high irradiance on the harmful dinoflagellate Akashiwo sanguinea, isolated at Dongtou Island, Eastern China Sea. The A. sanguinea cells were acclimated in high CO 2 condition for about three months before testing the responses of cells to a full factorial matrix experimentation during a 7-day period. This study measured the variation in physiological parameters and hemolytic activity in 8 treatments, representing full factorial combinations of 2 levels each of exposure to CO 2 (400 and 1000μatm), temperature (20 and 28°C) and irradiance (50 and 200μmol photons m -2 s -1 ). Sustained growth of A. sanguinea occurred in all treatments, but high CO 2 (HC) stimulated faster growth than low CO 2 (LC). The pigments (chlorophyll a and carotenoid) decreased in all HC treatments. The quantum yield (F v /F m ) declined slightly in all high-temperature (HT) treatments. High irradiance (HL) induced the accumulation of ultraviolet-absorbing compounds (UV abc ) irrespective of temperature and CO 2 . The hemolytic activity in the LC treatments, however, declined when exposed to HT and HL, but HC alleviated the adverse effects of HT and HL on hemolytic activity. All HC and HL conditions and the combinations of high temperature*high light (HTHL) and high CO 2 *high temperature*high light (HCHTHL) positively affected the growth in comparison to the low CO 2 *low temperature*low light (LCLTLL) treatment. High temperature (HT), high light (HL) and a combination of HT*HL, however, negatively impacted hemolytic activity. CO 2 was the main factor that affected the growth and hemolytic activity. There were no significant interactive effects of CO 2 *temperature*irradiance on growth

Behavior of radioisotope in liquid neutron irradiated Pb-17Li eutectic

International Nuclear Information System (INIS)

Tebus, V.N.; Aksenov, B.S.; Klabukov, U.G.

1994-01-01

Investigation of radioisotope 210 Po evaporation from liquid neutron irradiated Pb- 17 Li eutectic has been performed by Knudsen method. Equilibrium 210 Po vapor pressures at temperatures 250-700 degrees C were found about 3-4 orders of magnitude less than that for pure Po and were closed to equilibrium vapor pressures of Po-Pb compound. It was proposed Po forms stable Po-Pb compounds in eutectic at temperatures up to 750-800 degrees C. But disintegrates during long storage owing to self irradiation. It was determined Po aerosol transfer with radio gases takes place at the melting period. Contamination is happened also under irradiated eutectic storage at room temperature owing to aggregate recoil characteristic of Po

Effect of microwave irradiation on germination and seedling growth physiological characteristics of alfalfa seeds after storage

International Nuclear Information System (INIS)

Chen Liyu; Zhang Shuqing; Li Jianfeng; Shi Shangli; Huo Pinghui

2012-01-01

In order to study the effect of microwave irradiation on germination and growth physiological characteristics of seeds that stored for years, the irradiated alfalfa seeds that stored at room temperature for 2 years were used to conduct the germination and pot culture tests, and the germination rate, radical elongation, growth height, individual nodule, nitrogenase activity, chlorophyll content and chlorophyll fluorescence parameters were measured. On the 15th day of germination, the germination rates of all the treatments are higher than that of the control, which decrease with the elongation of time. On the llst day of germination, the radical length of all the treatments is lower than that of the control. Growth height, individual nodule, fresh weight and dry weight for the 40 s irradiation treatment are higher than that of the control. Nitrogenase activity of all the treatments is lower than that of the control (P < O.05). The chlorophyll content reaches its maximum when being irradiated for 10 s, and the variation for F 0 and F v /F m of all treatments indicates that the light conversion efficiency of the leaves derived from the irradiated alfalfa seeds that stored for 2 a at room temperature is still relatively stressed. (authors)

On the influence of total solar irradiance on global land temperature

International Nuclear Information System (INIS)

Varonov, Albert; Shopov, Yavor

2014-01-01

Using statistical analysis, correlation between the variations of the total solar irradiance and of the annual-mean land temperatures was found. An unknown time lag between both data sets was expected to be present due to the complexity of the Earth’s climate system leading to a delayed response to changes in influencing factors. We found the best correlation with coefficient over 90% for a 14-year shift of the annual mean land temperature record ahead with data until 1970, while the same comparison with data until 2006 yields 61% correlation. These results show substantially higher influence of total solar irradiance on global land temperatures until 1970. The decline of this influence during the last 40 years could be attributed to the increasing concentration of anthropogenic greenhouse gases in the Earth’s atmosphere. Key words: total solar irradiance, solar variations, solar forcing, climate change

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)

Effects of H-implantation energy on the optical stability of implanted usher films under photo-irradiation

International Nuclear Information System (INIS)

Awazu, K.; Yasui, H.; Kasamori, M.; Ichikawa, T.; Funada, Y.; Iwaki, M.

1999-01-01

A study has been made on the improvement of the optical stability of urushi films under optical irradiation using ion implantation. Ion implantation of hydrogen ions in urushi films was performed with a dose of 10 15 ions/cm 2 at ion energies ranging from 0.2 to 150 keV at room temperature. The photo-irradiation onto the urushi films was carried out at irradiation energies ranging from 40 to 400 MJ/m 2 . H-implantation onto urushi films is useful for improving the optical stability under photo-irradiation when the implantation energy is larger than 60 keV

Update of the Picker C9 irradiator control system of the gamma II room of the secondary laboratory of dosimetric calibration; Actualizacion del sistema de control del irradiador Picker C9 de la sala gamma II del laboratorio secundario de calibracion dosimetrica

Energy Technology Data Exchange (ETDEWEB)

Simon S, L. E.

2016-07-01

The Picker C9 irradiator is responsible for the calibration of different radiological equipment and the control system that maintains it in operation is designed in the graphical programming software LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench), being its major advantages: the different types of communication, easy interconnection with other software and the recognition of different hardware devices, among others. Operation of the irradiator control system is performed with the NI-Usb-6008 (DAQ) data acquisition module of the National Instruments Company. The purpose of this work is to update the routines that make the Picker C9 control system of the gamma II room of the secondary laboratory of dosimetric calibration, using the graphic programming software LabVIEW, as well as to configure the new acquisition hardware of data that is implemented to control the Picker C9 irradiator system and ensure its operation. (Author)

Man and the climate

International Nuclear Information System (INIS)

Dron, D.; Hirschhorn, C.

2002-01-01

The aim of this report is explain and balance the real dangers associated with the climate changes that may result from human activities, those which lack some scientific background, and the precaution and prudence needs which are claimed by human beings and society. The main parts of the report are: the scientific aspects of climate changes (inventory of present knowledge, assessment of uncertainties; what are greenhouse effect, which sectors of human activities are emitting greenhouse gases, what are the threats for our planet); the international negotiations on climate (their stakes and problematic since the start of the 90's, is a world consensus possible?); the room for maneuver on economical, social and technological levels in order to decrease the greenhouse gas emissions and allocate the application of solutions between States, enterprises and citizens

Tensile and shear fracture behavior of fiber reinforced plastics at 77K irradiated by various radiation sources

International Nuclear Information System (INIS)

Humer, K.; Weber, H.W.; Tschegg, E.K.; Gerstenberg, H.

1993-08-01

Influence of radiation damage (gamma, electron, neutron) on mechanical properties of fiber reinforced plastics (FRPs) has been investigated. Different types of FRPs (two or three dimensional E-, S- or T-glass fiber reinforcement, epoxy or bismaleimide resin) have been irradiated at room temperature with 2 MeV electrons and 6O Co γ-rays up to 1.8 x 1 0 8 Gy as well as with different reactor spectra up to a fast neutron fluence of 5 x lO 22 m -2 (E > 0.1 MeV). Tensile and intralaminar shear tests were carried out on the irradiated samples at 77 K. Some samples were irradiated at 5 K and tested at 77 K with and without an annealing cycle to room temperature. Results on the influence of these radiation conditions and of warm-up cycles on the mechanical properties of FRPs are compared and discussed

Prediction of diffuse solar irradiance using machine learning and multivariable regression

International Nuclear Information System (INIS)

Lou, Siwei; Li, Danny H.W.; Lam, Joseph C.; Chan, Wilco W.H.

2016-01-01

Highlights: • 54.9% of the annual global irradiance is composed by its diffuse part in HK. • Hourly diffuse irradiance was predicted by accessible variables. • The importance of variable in prediction was assessed by machine learning. • Simple prediction equations were developed with the knowledge of variable importance. - Abstract: The paper studies the horizontal global, direct-beam and sky-diffuse solar irradiance data measured in Hong Kong from 2008 to 2013. A machine learning algorithm was employed to predict the horizontal sky-diffuse irradiance and conduct sensitivity analysis for the meteorological variables. Apart from the clearness index (horizontal global/extra atmospheric solar irradiance), we found that predictors including solar altitude, air temperature, cloud cover and visibility are also important in predicting the diffuse component. The mean absolute error (MAE) of the logistic regression using the aforementioned predictors was less than 21.5 W/m"2 and 30 W/m"2 for Hong Kong and Denver, USA, respectively. With the systematic recording of the five variables for more than 35 years, the proposed model would be appropriate to estimate of long-term diffuse solar radiation, study climate change and develope typical meteorological year in Hong Kong and places with similar climates.

Impact of neutron irradiation on thermal helium desorption from iron

Energy Technology Data Exchange (ETDEWEB)

Hu, Xunxiang, E-mail: hux1@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Field, Kevin G. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Taller, Stephen [University of Michigan, Ann Arbor, MI 48109 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Wirth, Brian D. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); University of Tennessee, Knoxville, TN 37996 (United States)

2017-06-15

The synergistic effect of neutron irradiation and transmutant helium production is an important concern for the application of iron-based alloys as structural materials in fission and fusion reactors. In this study, we investigated the impact of neutron irradiation on thermal helium desorption behavior in high purity iron. Single crystalline and polycrystalline iron samples were neutron irradiated in HFIR to 5 dpa at 300 °C and in BOR-60 to 16.6 dpa at 386 °C, respectively. Following neutron irradiation, 10 keV He ion implantation was performed at room temperature on both samples to a fluence of 7 × 10{sup 18} He/m{sup 2}. Thermal desorption spectrometry (TDS) was conducted to assess the helium diffusion and clustering kinetics by analyzing the desorption spectra. The comparison of He desorption spectra between unirradiated and neutron irradiated samples showed that the major He desorption peaks shift to higher temperatures for the neutron-irradiated iron samples, implying that strong trapping sites for He were produced during neutron irradiation, which appeared to be nm-sized cavities through TEM examination. The underlying mechanisms controlling the helium trapping and desorption behavior were deduced by assessing changes in the microstructure, as characterized by TEM, of the neutron irradiated samples before and after TDS measurements.

Electron irradiation of zeolites

International Nuclear Information System (INIS)

Wang, S.X.; Wang, L.M.; Ewing, R.C.

1999-01-01

Three different zeolites (analcime, natrolite, and zeolite-Y) were irradiated with 200 keV and 400 keV electrons. All zeolites amorphized under a relatively low electron fluence. The transformation from the crystalline-to-amorphous state was continuous and homogeneous. The electron fluences for amorphization of the three zeolites at room temperature were: 7.0 x 10 19 e - /cm 2 (analcime), 1.8 x 10 20 e - /cm 2 (natrolite), and 3.4 x 10 20 e - /cm 2 (zeolite-Y). The different susceptibilities to amorphization are attributed to the different channel sizes in the structures which are the pathways for the release of water molecules and Na + . Natrolite formed bubbles under electron irradiation, even before complete amorphization. Analcime formed bubbles after amorphization. Zeolite-Y did not form bubbles under irradiation. The differences in bubble formation are attributed to the different channel sizes of the three zeolites. The amorphization dose was also measured at different temperatures. An inverse temperature dependence of amorphization dose was observed for all three zeolites: electron dose for amorphization decreased with increasing temperature. This unique temperature effect is attributed to the fact that zeolites are thermally unstable. A semi-empirical model was derived to describe the temperature effect of amorphization in these zeolites

Influence of gamma irradiation on microbiological and chemical characteristics of shelled and unshelled stored pecan (carya illinoinsis)

International Nuclear Information System (INIS)

Abd El Wahab, S.A.E.; El Salhy, F.T.A.; Mahmoud, A.M.

2010-01-01

Shelled and unshelled pecan nuts were treated with 0,1.53 and 5 kGy of gamma irradiation . The irradiated and non-irradiated nuts were stored in polyethylene bags for 0,2,4,6, and 8 months at room temperature. Total bacterial count and total mold and yeast, proximate composition (moisture, protein, fat and ash content), total free amino acids, total fatty acids, reducing and non-reducing sugars, phosphorous and potassium of nuts were evaluated immediately after irradiation and after each storage period . The results indicated that gamma irradiation reduced total bacterial count and total fungal load of pecan. Irradiation doses did not cause any significant changes in proximate composition of pecan.

Methanolysis of triolein by low frequency ultrasonic irradiation

Energy Technology Data Exchange (ETDEWEB)

Hanh, Hoang Duc; Starvarache, Carmen; Okitsu, Kenji; Maeda, Yasuaki; Nishimura, Rokuro [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan); Dong, Nguyen The [Institute of Environmental Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam)

2008-02-15

Methanolysis of triolein was investigated at room temperature by 40 kHz ultrasonic irradiation to make biodiesel fuel as methyl esters. It was found that the yield of methyl esters strongly depended on the amount of KOH and the molar ratio of methanol to triolein (M/T) and was highest at the M/T molar ratio of 6/1, KOH concentration of 1 wt% and irradiation time of 30 min. In addition, the effects of sonication on the methanolysis of triolein were discussed in comparison to the effects of stirring experiments. The optimum condition under stirring experiments showed that the molar ratio of M/T, KOH concentration and reaction time were 6/1, 1.5 wt% and 4 h, respectively. These results clearly indicated that the ultrasonic irradiation method would be a promising one compared to the conventional stirring method. The high yield under the ultrasonic irradiation condition would be due to high speed mixing and mass transfer between the methanol and triolein as well as the formation of a microemulsion resulting from the ultrasonic cavitation phenomenon. (author)

Methanolysis of triolein by low frequency ultrasonic irradiation

Energy Technology Data Exchange (ETDEWEB)

Hoang Duc Hanh [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan)], E-mail: hoangduchanh75@yahoo.com; Nguyen The Dong [Institute of Environmental Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam); Starvarache, Carmen; Okitsu, Kenji; Maeda, Yasuaki; Nishimura, Rokuro [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan)

2008-02-15

Methanolysis of triolein was investigated at room temperature by 40 kHz ultrasonic irradiation to make biodiesel fuel as methyl esters. It was found that the yield of methyl esters strongly depended on the amount of KOH and the molar ratio of methanol to triolein (M/T) and was highest at the M/T molar ratio of 6/1, KOH concentration of 1 wt% and irradiation time of 30 min. In addition, the effects of sonication on the methanolysis of triolein were discussed in comparison to the effects of stirring experiments. The optimum condition under stirring experiments showed that the molar ratio of M/T, KOH concentration and reaction time were 6/1, 1.5 wt% and 4 h, respectively. These results clearly indicated that the ultrasonic irradiation method would be a promising one compared to the conventional stirring method. The high yield under the ultrasonic irradiation condition would be due to high speed mixing and mass transfer between the methanol and triolein as well as the formation of a microemulsion resulting from the ultrasonic cavitation phenomenon.

Food irradiation: Public opinion surveys

International Nuclear Information System (INIS)

Kerr, S.D.

1987-01-01

The Canadian government are discussing the legislation, regulations and practical protocol necessary for the commercialization of food irradiation. Food industry marketing, public relations and media expertise will be needed to successfully introduce this new processing choice to retailers and consumers. Consumer research to date including consumer opinion studies and market trials conducted in the Netherlands, United States, South Africa and Canada will be explored for signposts to successful approaches to the introduction of irradiated foods to retailers and consumers. Research has indicated that the terms used to describe irradiation and information designed to reduce consumer fears will be important marketing tools. Marketers will be challenged to promote old foods, which look the same to consumers, in a new light. Simple like or dislike or intention to buy surveys will not be effective tools. Consumer fears must be identified and effectively handled to support a receptive climate for irradiated food products. A cooperative government, industry, health professional, consumer association and retailer effort will be necessary for the successful introduction of irradiated foods into the marketplace. Grocery Products Manufacturers of Canada is a national trade association of more than 150 major companies engaged in the manufacture of food, non-alcoholic beverages and array of other national-brand consumer items sold through retail outlets

Contribution of Brazil nut shell fiber and electron-beam irradiation in thermomechanical properties of HDPE

International Nuclear Information System (INIS)

Polato, Pamella; Lorusso, Leandro Alex; Souza, Clecia de Moura; Moura, Esperidiana Augusta Barretos de; Chinellato, Anne; Rosa, Ricardo de

2010-01-01

In the present work, the influence of electron-beam irradiation on thermo-mechanical properties of HDPE and HDPE/Brazil nut shell fiber composite was investigated. The materials were irradiated at radiation dose 50 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. The irradiated and non-irradiated samples were submitted to thermo-mechanical tests and the correlation between their properties was discussed. The results showed that the incorporation of Brazil nut shell fiber represented a significant gain (p < 0,05) in tensile strength at break, flexural strength, flexural module, Vicat softening temperature and heat distortion temperature (HDT) properties of the HDPE. In addition, the irradiated HDPE/Brazil nut shell fiber composite presented a significant increase (p < 0.05) in this properties compared with irradiated HDPE. (author)

Some folded issues related to over-shielded and unplanned rooms for medical linear accelerators - A case study

Science.gov (United States)

Muhammad, Wazir; Ullah, Asad; Hussain, Amjad; Ali, Nawab; Alam, Khan; Khan, Gulzar; Matiullah; Maeng, Seongjin; Lee, Sang Hoon

2015-08-01

A medical linear accelerator (LINAC) room must be properly shielded to limit the outside radiation exposure to an acceptable safe level defined by individual state and international regulations. However, along with this prime objective, some additional issues are also important. The current case-study was designed to unfold the issues related to over-shielded and unplanned treatment rooms for LINACs. In this connection, an apparently unplanned and over-shielded treatment room of 610 × 610 cm2 in size was compared with a properly designed treatment room of 762 × 762 cm2 in size ( i.e., by following the procedures and recommendations of the IAEA Safety Reports Series No. 47 and NCRP 151). Evaluation of the unplanned room indicated that it was over-shielded and that its size was not suitable for total body irradiation (TBI), although the license for such a treatment facility had been acquired for the installed machine. An overall 14.96% reduction in the total shielding volume ( i.e., concrete) for an optimally planned room as compared to a non-planned room was estimated. Furthermore, the inner room's dimensions were increased by 25%, in order to accommodate TBI patients. These results show that planning and design of the treatment rooms are imperative to avoid extra financial burden to the hospitals and to provide enough space for easy and safe handling of the patients. A spacious room is ideal for storing treatment accessories and facilitates TBI treatment.

EPR investigation of gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine

Science.gov (United States)

Osmanoğlu, Y. Emre; Sütçü, Kerem; Başkan, M. Halim

2017-02-01

The spectroscopic parameters of the paramagnetic species produced in gamma-irradiated L-citrulline, α-methyl-DL-serine, 3-fluoro-DL-valine and N-acetyl-L-cysteine were investigated at room temperature at a dose of 20 kGy by using EPR technique. The paramagnetic species were attributed to NH2CONH(CH2)3ĊNH2COOH, HOCH2ĊCH3COOH and HOĊHCCH3NH2COOH, CH3CH3ĊCHNH2COOH and SHCH2ĊNHCOCH3COOH radicals, respectively. EPR data of the unpaired electron with the environmental protons and 14N nucleus were used to characterize the contributing radicals produced in gamma irradiated compounds. In this paper, the stability of these compounds at room temperature after irradiation was also studied.

Clouds and the Earth's Radiant Energy System (CERES) Data Products for Climate Research

Science.gov (United States)

Kato, Seiji; Loeb, Norman G.; Rutan, David A.; Rose, Fred G.

2015-01-01

NASA's Clouds and the Earth's Radiant Energy System (CERES) project integrates CERES, Moderate Resolution Imaging Spectroradiometer (MODIS), and geostationary satellite observations to provide top-of-atmosphere (TOA) irradiances derived from broadband radiance observations by CERES instruments. It also uses snow cover and sea ice extent retrieved from microwave instruments as well as thermodynamic variables from reanalysis. In addition, these variables are used for surface and atmospheric irradiance computations. The CERES project provides TOA, surface, and atmospheric irradiances in various spatial and temporal resolutions. These data sets are for climate research and evaluation of climate models. Long-term observations are required to understand how the Earth system responds to radiative forcing. A simple model is used to estimate the time to detect trends in TOA reflected shortwave and emitted longwave irradiances.

Diffusion and solubility of oxygen in γ-ray irradiated polymer insulation materials

International Nuclear Information System (INIS)

Seguchi, Tadao; Yamamoto, Yasuaki.

1986-03-01

The effects of 60 Co γ-rays irradiation on diffusion and solubility of oxygen in polymer materials for electric cable insulation materials were investigated. The polymers were polyethylene, ethylene-propylene rubber, chlorinated polyethylene, chlorosulphonated polyethylene, and chloroprene rubber. They were pure grade and several types of formulation grade. The sheets of these polymers were irradiated up to 5 - 200 Mrad under vacuum or in oxygen under pressure of 3 - 15 atm at room temperature or at 70 deg C. By a method of gas desorption, the diffusion coefficient (D) and solubility coefficient (S) of oxygen or argon in polymer materials were determined at various temperatures of 10 - 80 deg C. The D and S decreased with increase of dose, and the decrease by irradiation with oxidation was more remarkable than that by irradiation without oxidation. However, the decreases of D and S by irradiation were reduced by the formulation of polymers. The additives in formulated polymers would reduce the reactions of crosslinking or oxidation by γ-ray irradiation. The activation energy of D was scarcely changed by irradiations with and without oxidation. (author)

222Radon concentration and irradiation dose inside the department of nuclear medicine in Wuhan

International Nuclear Information System (INIS)

Cheng Xiaoli; Wang Changyin; Gao Jianhua; Zou Xiaofeng

2002-01-01

Objective: Inspecting the high radioactivity area in department of nuclear medicine in Wuhan region and estimating the irradiation dose on relevant doctors. Methods: Select six 'three A' hospitals' high radioactivity area in department of nuclear medicine and common residential houses as examples. A half-year surveillance using 222 Rn detector (type LIH-2) was performed. Results: In high radioactivity rooms, imaging rooms residential houses, the average 222 Rn concentration are 27.8, 48.2, 27.1 (Bq·m -3 ) respectively. Effective dose equivalent absorbed by doctors in high radioactivity room and imaging room are 0.16 and 0.28 mSv. The authors estimated that the effective dose equivalent of doctors in these two room and common residents per year are 0.84, 0.70 and 0.64 mSv respectively. Conclusions: Doctors in imaging room and high radioactivity room are exposed to a relatively higher annual effective dose than common residents. But they are still within the normal range. Only two imaging rooms have high 222 Rn concentrations, which will cause potential harm

A theoretical and experimental dose rate study at a multipurpose gamma irradiation facility in Ghana

International Nuclear Information System (INIS)

Sackey, Tracey A.

2015-01-01

Radiation dose rate monitoring out at the Radiation Technology Centre (RTC) of the Ghana Atomic Energy Commission (GAEC) to establish the safety or otherwise of staff at the occupied areas is presented. The facility operates a rectangular source of Co-60 gamma with an having activity of 27.4kCi as at March 2015 and has 14 workers. The aim of the research was determine by means of practical and theoretical evaluations shielding effectiveness of the irradiation chamber. This was to ensure that occupationally exposed workers are not over exposed or their exposures do not exceed the regulatory limits of 7.5μSv/h or 50mSv per annum. The study included dose rate measurements at controlled areas, evaluation of personnel dose history, comparison of experimental and theoretical values and determination of whether the shielding can support a. 18.5PBq (500kCi) Co-60 source. Practical dose rate measurements when the source was in the irradiation position was carried out using a Thermo Scientific Rad-Eye Gamma Survey Meter in the controlled areas of the facility which included the control room, electric room, deionizer room, on top of the roof of irradiation chamber (specifically above the roof plugs) and the two entrances to the irradiation chamber; the personnel door and the goods door. Background reading was found to be 0.08±0.01μSv/h whilst the average dose rates at the two entrances to the irradiation chamber (i e.,- the personnel door and the goods door) were measured to be 0.090μSv/h and 0.109μSv/h respectively. Practical measurements at the roof plugs produced average values of 0.135μSv/h. A particular point on the roof marked as plug-3 produced a relatively higher dose rate of 8.151μSv/h due probably to leakage along the cable to the drive motor. Measurements in the control room, electrical room and deionizer room had average readings of 0.116μSv/h, 0.089μSv/h and 0.614μSv/h respectively. All these average values were below the regulatory limits of 7.5�

ESR analysis of natural and gamma irradiated coriander (Coriandrum sativum L.) seeds

Science.gov (United States)

Sezer, M. Özgür; Kaplan, Necati; Sayin, Ulku

2017-12-01

Electron spin resonance (ESR) is a powerful technique to detect radicals trapped in cellulosic food products and has been suggested as a useful method for identification of irradiated herbal foodstuffs. Coriander spice which has important medicinal properties was investigated using ESR spectroscopy. Radicals in natural and irradiated coriander samples were determined at room temperature. ESR spectra of natural sample were characterized by a single central signal with ? value and gamma irradiation produced satellite peaks attributed to cellulose-like radical which is used as a marker for detection of irradiated cellulosic plant products. The spectroscopic splitting values of radicals were determined. Dose dependency and stability of this center were analyzed by dose response and kinetic measurements. The reported results about activation energy, thermal life time and dose response relationship of the cellulose-like radical accurately prove that ESR can be used for identification of irradiated coriander spice seeds.

Room temperature Cu-Cu direct bonding using surface activated bonding method

International Nuclear Information System (INIS)

Kim, T.H.; Howlader, M.M.R.; Itoh, T.; Suga, T.

2003-01-01

Thin copper (Cu) films of 80 nm thickness deposited on a diffusion barrier layered 8 in. silicon wafers were directly bonded at room temperature using the surface activated bonding method. A low energy Ar ion beam of 40-100 eV was used to activate the Cu surface prior to bonding. Contacting two surface-activated wafers enables successful Cu-Cu direct bonding. The bonding process was carried out under an ultrahigh vacuum condition. No thermal annealing was required to increase the bonding strength since the bonded interface was strong enough at room temperature. The chemical constitution of the Cu surface was examined by Auger electron spectroscope. It was observed that carbon-based contaminations and native oxides on copper surface were effectively removed by Ar ion beam irradiation for 60 s without any wet cleaning processes. An atomic force microscope study shows that the Ar ion beam process causes no surface roughness degradation. Tensile test results show that high bonding strength equivalent to bulk material is achieved at room temperature. The cross-sectional transmission electron microscope observations reveal the presence of void-free bonding interface without intermediate layer at the bonded Cu surfaces

Three-dimensional point-cloud room model in room acoustics simulations

DEFF Research Database (Denmark)

Markovic, Milos; Olesen, Søren Krarup; Hammershøi, Dorte

2013-01-01

acquisition and its representation with a 3D point-cloud model, as well as utilization of such a model for the room acoustics simulations. A room is scanned with a commercially available input device (Kinect for Xbox360) in two different ways; the first one involves the device placed in the middle of the room...... and rotated around the vertical axis while for the second one the device is moved within the room. Benefits of both approaches were analyzed. The device's depth sensor provides a set of points in a three-dimensional coordinate system which represents scanned surfaces of the room interior. These data are used...... to build a 3D point-cloud model of the room. Several models are created to meet requirements of different room acoustics simulation algorithms: plane fitting and uniform voxel grid for geometric methods and triangulation mesh for the numerical methods. Advantages of the proposed method over the traditional...

Three-dimensional point-cloud room model for room acoustics simulations

DEFF Research Database (Denmark)

Markovic, Milos; Olesen, Søren Krarup; Hammershøi, Dorte

2013-01-01

acquisition and its representation with a 3D point-cloud model, as well as utilization of such a model for the room acoustics simulations. A room is scanned with a commercially available input device (Kinect for Xbox360) in two different ways; the first one involves the device placed in the middle of the room...... and rotated around the vertical axis while for the second one the device is moved within the room. Benefits of both approaches were analyzed. The device's depth sensor provides a set of points in a three-dimensional coordinate system which represents scanned surfaces of the room interior. These data are used...... to build a 3D point-cloud model of the room. Several models are created to meet requirements of different room acoustics simulation algorithms: plane fitting and uniform voxel grid for geometric methods and triangulation mesh for the numerical methods. Advantages of the proposed method over the traditional...

γ-irradiated crystalline sugars and amino acids: A chemical analysis

International Nuclear Information System (INIS)

Gejvall, T.

1975-01-01

Crystalline sugars and amino acids were irradiated at room temperature in a 60 Co γ-source at a dose rate ranging from 2 to 3x10 19 eV/g per hour. The investigation has geen performed to broaden the knowledge about what happens to food at irradiation preservation. The total degradation and the role of the glycosidic bond were investigated in some carbonhydrates. Transfer reactions of tritium constitute another specific problem which has been treated. Several components are formed in the crystalline amino acids, and a new gas chromatographic method was developed for analysis of amines in degraded material. (K.K)

Moessbauer study of amorphous alloys irradiated with energetic heavy ions

International Nuclear Information System (INIS)

Kuzmann, E.; Spirov, I.N.

1984-01-01

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

Effects of chronic gamma irradiation on adventitious plantlet formation of Saintpaulia ionantha (African violet) detached leaves

International Nuclear Information System (INIS)

Arunee Wongpiyasatid; Peeranuch Jompuk; Katarat Chusreeaeom; Thanya Taychasinpitak

2007-01-01

Formation of adventitious plantlets on unrootedly detached leaves of two African violet (Saintpaulia ionantha) cultivars, pink and violet flowers, chronically gamma-irradiated in gamma room at The Gamma Irradiation Service and Nuclear Technology Research Center, Kasetsart University was compared. Detached leaves were immediately planted after detachment in plastic trays containing peat moss, 18 leaves per treatment with 3 replications. Three dose rates (rad/h) with 3 doses (rad)/dose rate, were applied to the irradiated samples while the controls were placed outside the gamma room. Three months after irradiation, the number of survived leaves, the number of leaves producing adventitious plantlets and the number of plantlets per leaf were recorded. After that, the young plantlets were transferred to the new pots for further observation on plant growth and mutation characters. The results revealed that the number of survived leaves, the number of leaves producing adventitious plantlets and the number of plantlets per leaf varied slightly with radiation doses but were not significantly different at different dose rates. Radiosensitivity was noticed to be higher in pink flower cultivar than the violet one. M 1 V 1 plantlets will be followed up for growth and mutation character observations

Identification of irradiated mangoes by means of ESR spectroscopy

International Nuclear Information System (INIS)

Bustos, M.E.; Romero, M.E.; Gutierrez, A.; Azorin, J.

1996-01-01

Samples of mango varieties Tommy Atkins, Haiden and Ataulfo were irradiated with 60 Co gamma radiation at doses in the range 0.15-1.0 kGy, and stored at room temperature for lapses of time up to 72 h. They were then studied by ESR spectrometry. Results show that the ESR signal of the irradiated samples is higher than that of the unirradiated samples, and this is found even at the minimum radiation dose of 0.15 kGy. The ESR signal remained stable during the storage time. The ESR signals obtained for hydroheated mangoes show insignificant differences with respect to the control samples. (author)

Effect of irradiation and other processing methods on nutritional and technological qualities of foods

International Nuclear Information System (INIS)

Aurangzeb; Bibi, N.; Ahmad, M.; Sattar, A.; Khan, I.

1989-01-01

The present project was undertaken to investigate the effect of different doses of gamma irradiation on food. The water uptake and cooking behavior of irradiated food after a sufficient time at room temperature was also studied. It was observed that protein contents for fresh vegetable are maximum and minimum for fried vegetables. The nutrient retention in different treatment was calculated and found in the decreasing order of simmering, boiling, roasting and frying. (A.B.)

An electron beam irradiation method for modification of surface electrical resistivity of polyamides

International Nuclear Information System (INIS)

Brasoveanu, M. M.; Timus, D.; Nemtanu, M. R.

2002-01-01

The synthetic textiles which have mechanical and processing properties and a low price are very useful and consequently in high demand. The low antistatic qualities are an important disadvantage, but not impossible to eliminate. The aim of paper is the study of modification the antistatic properties of polyamide by grafting of monomers by irradiation. Twisted and unthermofixed polyamide-6 fibre from CFS Savinesti were investigated. The samples of polyamide were irradiated with an electron beam from the ALIN-7 linear accelerator of Electron Accelerators Laboratory of National Institute for Lasers, Plasma and Radiation Physics, Bucharest. Immediately after irradiation, the samples were measured by electron spin resonance (ESR). ESR spectra were recorded at room temperature using a Jeol spectrometer, JES-ME-3X, with 100 kHz modulation. In polyamide-6 at least two irradiation defect types occurred which present EPR signal by electron beam irradiation. Unstable centres of type A presenting an incompletely resolved hyperfine structure can be attributed to radicals -N-CH 2 - or -NH-CH-CH 2 -. Both radicals can present at room temperature a five-line spectrum like the radical formed in this work. First radical appears with very low probability and if the free bond is at one of carbon atoms then it will be stabilized immediately in a position from nitrogen. These type A radicals can appear in same zone and then they can react and form unsaturated bonds or bridge between the polymeric chains. Thus, it will appear the type B defects which were more stabile and without structure. On these double chains one can graft vinylic monomers even after time intervals longer from irradiation. (authors)

1.5 MeV Kr+ irradiation of polycrystalline Ge

International Nuclear Information System (INIS)

Wang, L.M.; Birtcher, R.C.; Rehn, L.E.

1990-01-01

This paper reports 1.5 MeV Kr + irradiation of polycrystalline Ge at room temperature, and subsequent annealing carried out with in situ TEM observations. After a Kr + dose of 1.2 x 10 14 ions/cm 2 , Ge in the electron transparent region was completely amorphized. Continuous irradiation of the amorphized Ge resulted in a high density of small cavities. These cavities, first observed after 7 x 10 14 ions/cm 2 with an average diameter of ∼3 nm, grew into large (∼50 nm) irregular-shaped holes, transforming the irradiated Ge into a sponge-like material after 8.5 x 10 15 ions/cm 2 . The crystallization temperature and the morphology of the crystallized Ge after annealing were found to be dependent on the Kr + dose. The sponge-like structure was retained after crystallization at ∼600 degrees C

An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

OpenAIRE

Scheuerlein, C; Hilleret, Noël; Taborelli, M; Brown, A; Baker, M A

2002-01-01

The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis resu...

Positron annihilation lifetime characterization of oxygen ion irradiated rutile TiO2

Science.gov (United States)

Luitel, Homnath; Sarkar, A.; Chakrabarti, Mahuya; Chattopadhyay, S.; Asokan, K.; Sanyal, D.

2016-07-01

Ferromagnetic ordering at room temperature has been induced in rutile phase of TiO2 polycrystalline sample by O ion irradiation. 96 MeV O ion induced defects in rutile TiO2 sample has been characterized by positron annihilation spectroscopic techniques. Positron annihilation results indicate the formation of cation vacancy (VTi, Ti vacancy) in these irradiated TiO2 samples. Ab initio density functional theoretical calculations indicate that in TiO2 magnetic moment can be induced either by creating Ti or O vacancies.

Evolution of extended defects in polycrystalline Au-irradiated UO{sub 2} using in situ TEM: Temperature and fluence effects

Energy Technology Data Exchange (ETDEWEB)

Onofri, C., E-mail: claire.onofri@cea.fr [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Sabathier, C. [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Baumier, C.; Bachelet, C. [CSNSM/CNRS, PARIS-SUD University, F-91400 Orsay (France); Palancher, H. [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Legros, M. [CEMES/CNRS, F-31055 Toulouse Cedex 4 (France)

2016-12-15

In situ Transmission Electron Microscopy irradiations were performed on polycrystalline UO{sub 2} thin foils with 4 MeV gold ions at three different temperatures: 600 °C, room and liquid nitrogen temperature. In order to study the dislocation evolution and to determine the growth mechanisms, the dislocation loop and line densities and the loop size repartition were monitored as a function of fluence, and irradiation temperature. We show that dislocation loops, with Burgers vectors along the <110> directions, evolve into dislocation lines with increasing fluence by a loop overlapping mechanism. Furthermore, a fluence offset is highlighted between the irradiations performed at high and low temperature due to an increase of the defect mobility. Indeed, a growth by Oswald ripening is probably activated at room temperature and 600 °C and changes the kinetic evolution of loops into lines. After this transformation, and for all the irradiation temperatures, a steady state equilibrium is reached where both extended defects (dislocation lines and small dislocations loops -around 5 nm in size-) are observed simultaneously. A continuous nucleation of small dislocation loops and of nanometer-sized cavities formed directly by irradiation is also highlighted.

An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

CERN Document Server

Scheuerlein, C; Taborelli, M; Brown, A; Baker, M A

2002-01-01

The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis results are compared with electron dose dependent secondary electron and electron stimulated desorption yield measurements. Initially the electron irradiation causes a surface cleaning through electron stimulated desorption, in particular of hydrogen. During this period both the electron stimulated desorption and secondary electron yield decrease as a function of electron dose. When the electron dose exceeds 10-4 C mm-2 electron stimulated desorption yields are reduced by several orders of magnitude and the electron beam indu...

Biosolubilization gamma irradiate ion result coal by mould trichoderma sp

International Nuclear Information System (INIS)

Pingkan Aditiawati; Dea Indriani Astuti; Irawan Sugoro; Dwiwahju Sasongko

2011-01-01

Biosolubilization of coal is process of converting solid coal to liquid fuel/chemicals by mean of microorganism. The aim of this research was to study the effect of gamma rays irradiation with varian doses of irradiation into solubilization of subbituminous coal by Trichoderma sp. The dosage used was 5, 10, and 20 kGy and unirradiated coal as control. The method was submerged culture in MSS+ medium and incubated at room temperature and agitated at 150 rpm for 21 th days. The parameters observed were colonization, pH and biosolubilization product based on absorbance value at λ 250nm and λ 450nm and GC/MS analysis for the best treatment. The results showed that coal biosolubilization could be increased by gamma irradiation. The mould could growth well in medium containing irradiated coal and the medium of pH was decreased after incubation. The biosolubilization was increased but the irradiation dosage of coal didn't affect significantly. The best dose was 20 kGy with product biosolubilization similar to gasoline and solar. Based on the result, the pre-treatment of gamma irradiation on coal has potency to increased biosolubilization. (author)

Low temperature modification of gamma-irradiation effect on peas. II.Low temperature effect on the radio-sensitivity and the chlorophyll mutations

International Nuclear Information System (INIS)

Najdenova, N.; Vasileva, M.

1976-01-01

Dry pea seeds of cv.Ramonskii 77 with 11-12% moisture were γ-irradiated by 60 Co in doses 5, 15, 20 and 30 krad. Low temperature (-78 deg C) was effected in the form of dry ice for a 24 h period prior to, at the time of and post irradiation. As control were used: (a) dry non-irradiated seeds, stored at room temperature; (b) non-irradiated seeds subjected to low temperature (-78 deg C) for a 24 h period. and (c) seeds irradiated by the named doses, stored at room temperature until the time of irradiation. Treated and control seeds were sown in the field. Germination, survival rate and sterility were recorded in M 1 , while in M 2 chlorophyll mutations were scored. Results obtained showed that low temperature modification effect on the various irradiation doses depended on the time of its application; low temperature (-78 deg C) treatment prior to seed irradiation with doses 15, 20 and 30 krad increased germination percentage, plant survival and yield components in M 1 . The post-irradiation treatment did not have a significant effect on gamma-rays; highest protection effect was obtained in case seeds were irradiated at low temperature and then received supplementary treatment at high temperature. In this way the damaging effect of radiation was reduced to a maximum degree; low temperature treatment prior to irradiation with doses of 15 and 20 krad or at the time of irradiation with doses of 15, 20 and 30 krad resulted in a considerably wider chlorophyll mutation spectrum. (author)

ESR Study of PE, HDPE and UHMWPE Irradiated with Ion Beams and Neutrons

International Nuclear Information System (INIS)

Reyes-Romero, J.

2006-01-01

We report the Electron Spin Resonance (RES) studies on the effects produced by bombarding with accelerated Sulfur ions, Protons and Neutrons on the Polyethylene, PE, (Hostalen and Romanian), ultra-high molecular weight polyethylene, UHMWPE, ( GUR 1050, medical grade Lennite), and high density polyethylene, HDPE, (HDPE-7000F, Polinter de Venezuela, PDVSA). The resonance spectra have been recorded using a Varian E-line-X ESR spectrometer at 100 KHz modulation frequency. In thin films of Polyethylene (Hostalen and UHMWPE) have been irradiated with Sulfur ions, S, accelerated at about 7 MeV/nucleons, and Protons at about 5 MeV/nucleons (IFIN, Romania). Samples of Polyethylene ( HDPE 7000-F) were irradiate with neutrons from a Pu-Be source (flux of 1.19 x 10 6 n/s. cm 2 , 5.65 MeV, IVIC, Venezuela) from 0 to 8 hours in the presence of air and at room temperature (RT). The ESR measurements were performed after a storage time of about 7 months, in air at room temperature. The nature of the free radicals induced by irradiation as well as the dependence of resonance line, resonance line shape and radicals concentration has been studied

Co-doped sodium chloride crystals exposed to different irradiation temperature

Energy Technology Data Exchange (ETDEWEB)

Ortiz-Morales, A. [Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, IPN, Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico D.F., Mexico and Unidad de Irradiacion y Segurid (Mexico); Cruz-Zaragoza, E.; Furetta, C. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F (Mexico); Kitis, G. [Nuclear Physics Laboratory, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Flores J, C.; Hernandez A, J.; Murrieta S, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP. 20-364, 01000 Mexico D.F (Mexico)

2013-07-03

Monocrystals of NaCl:XCl{sub 2}:MnCl{sub 2}(X = Ca,Cd) at four different concentrations have been analyzed. The crystals were exposed to different irradiation temperature, such as at room temperature (RT), solid water (SW), dry ice (DI) and liquid nitrogen (LN). The samples were irradiated with photon from {sup 60}Co irradiators. The co-doped sodium chloride crystals show a complex structure of glow curves that can be related to different distribution of traps. The linearity response was analyzed with the F(D) index. The F(D) value was less than unity indicating a sub-linear response was obtained from the TL response on the function of the dose. The glow curves were deconvoluted by using the CGCD program based on the first, second and general order kinetics.

Radii and refractive index changes in γ-irradiated optical fibers

International Nuclear Information System (INIS)

Bertolotti, M.; Ferrari, A; Scudieri, F.; Serra, A.

1979-01-01

Radiation effects in bulk glasses have received great attention in the last few years. In optical fibers the parameters studied have been the optical attenuation at different wavelengths and the luminescence generated by irradiation. A report is presented on some preliminary experiments showing that sensible changes in both dimensions and refractive indices occur even in the case of simple defect introduction, as it is for γ-rays, and even at relatively low irradiation doses (e.g. 1 Krad). Moreover the effects anneal out at room temperature in a few days. The measurements have been made with an optical interferometric technique in which a comparison is made between an unirradiated reference fiber sample and the irradiated specimen. The fiber examined was a Pb-silicate core/borosilicate clad fiber. (U.K.)

Room with a View: Ethical Encounters in Room 13

Science.gov (United States)

Grube, Vicky

2012-01-01

In this article, the author describes ethical encounters in Room 13, a schoolroom where children made what they wanted, posed their own questions, and ran an art room like a small business. In Room 13 children had the responsibility to maintain all aspects of the art studio. Specific decisions fell to an annually elected management team, a small…

Tensile and shear fracture behavior of fiber reinforced plastics at 77K irradiated by various radiation sources

Energy Technology Data Exchange (ETDEWEB)

Humer, K.; Weber, H.W. [Atominstitut der Oesterreichischen Hochschulen, Vienna (Austria); Tschegg, E.K. [Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik; Egusa, Shigenori [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Birtcher, R.C. [Argonne National Lab., IL (United States); Gerstenberg, H. [Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Physik

1993-08-01

Influence of radiation damage (gamma, electron, neutron) on mechanical properties of fiber reinforced plastics (FRPs) has been investigated. Different types of FRPs (two or three dimensional E-, S- or T-glass fiber reinforcement, epoxy or bismaleimide resin) have been irradiated at room temperature with 2 MeV electrons and {sup 6O}Co {gamma}-rays up to 1.8 {times} 1 0{sup 8} Gy as well as with different reactor spectra up to a fast neutron fluence of 5 {times} lO{sup 22} m{sup {minus}2} (E > 0.1 MeV). Tensile and intralaminar shear tests were carried out on the irradiated samples at 77 K. Some samples were irradiated at 5 K and tested at 77 K with and without an annealing cycle to room temperature. Results on the influence of these radiation conditions and of warm-up cycles on the mechanical properties of FRPs are compared and discussed.

Development of shelf-stable meat sausages using gamma irradiation

International Nuclear Information System (INIS)

Seri Chempaka Mohd Yusof; Muhammad Lebai Juri; Mariani Deraman

2006-01-01

Irradiation techniques have been applied in development of ready to eat or shelf stable sausages. These sausages can be eaten directly without the need for prior heating or cooking procedure and displayed in the room temperature on the shelves of the retailers without frozen facilities. This study was designed to investigate the acceptability and microbial status of packed ready to eat sausages that had been sterilized using gamma irradiation at MINTec-Sinagama. Packed pre-cooked sausage samples (sealed in plastic-polyethylene individually) were irradiated with different doses of 2.5 kGy, 3.5 kGy and 5.5 kGy. Acceptability of the sausages was determined through sensory evaluation by 30 members of untrained panelists comprising of staffs of MINT. A 5 points hedonic rating scale was used. The attributes evaluated were rancidity, texture, chewiness, juiciness, aroma, colour, shape and overall acceptance. Samples irradiated with doses 3.5 kGy were the most acceptable followed by samples irradiated with doses 2.5 kGy and 5.5 kGy respectively. Irradiation with doses up to 2.5 kGy will virtually eliminate disease-causing microorganisms and pathogens. The total microbial count, detection of Salmonella, Escherichia coli, Staphylococcus aureus and fungi in these samples were determined and discussed. (Author)

The application of gamma irradiation for the extended commercial storage of root crops (onions and garlic) and shipping trials of irradiated frozen shrimp. Final report for the period 1 December 1985 - 31 December 1988

International Nuclear Information System (INIS)

Nouchpromool, K.

1988-01-01

The scope of the project was to demonstrate the efficiency of pilot scale radiation treatment of onions and garlic aiming toward the transfer of food irradiation technology to traders and to evaluate the quality of irradiated frozen shrimp shipped to Japan and australia after irradiation in Thailand. The tests demonstrated that the irradiation of onions (55-94 and 74-130 Gy) and garlic (50-90 Gy) to inhibit sprouting and reduce weight loss during commercial storage in cold room is technically feasible and economically justified. The bacteriological quality of frozen, peeled, cooked shrimps was improved by radiation treatment at doses of 1.2 to 3.3 kGy. 1 fig., 15 tabs

Operating room management and operating room productivity: the case of Germany.

Science.gov (United States)

Berry, Maresi; Berry-Stölzle, Thomas; Schleppers, Alexander

2008-09-01

We examine operating room productivity on the example of hospitals in Germany with independent anesthesiology departments. Linked to anesthesiology group literature, we use the ln(Total Surgical Time/Total Anesthesiologists Salary) as a proxy for operating room productivity. We test the association between operating room productivity and different structural, organizational and management characteristics based on survey data from 87 hospitals. Our empirical analysis links improved operating room productivity to greater operating room capacity, appropriate scheduling behavior and management methods to realign interests. From this analysis, the enforcing jurisdiction and avoiding advance over-scheduling appear to be the implementable tools for improving operating room productivity.

Distribution and Room Air Mixing Risks to Retrofitted Homes

Energy Technology Data Exchange (ETDEWEB)

Burdick, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2014-12-01

Energy efficiency upgrades reduce heating and cooling loads on a house. With enough load reduction and if the HVAC system warrants replacement, the HVAC system is often upgraded with a more efficient, lower capacity system that meets the loads of the upgraded house. For a single-story house with ceiling supply air diffusers, ducts are often removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling.

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

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)

Correlating TEM images of damage in irradiated materials to molecular dynamics simulations

International Nuclear Information System (INIS)

Schaeublin, R.; Caturla, M.-J.; Wall, M.; Felter, T.; Fluss, M.; Wirth, B.D.; Diaz de la Rubia, T.; Victoria, M.

2002-01-01

TEM image simulations are used to couple the results from molecular dynamics (MD) simulations to experimental TEM images. In particular we apply this methodology to the study of defects produced during irradiation. MD simulations have shown that irradiation of FCC metals results in a population of vacancies and interstitials forming clusters. The limitation of these simulations is the short time scales available, on the order of 100 s of picoseconds. Extrapolation of the results from these short times to the time scales of the laboratory has been difficult. We address this problem by two methods: we perform TEM image simulations of MD simulations of cascades with an improved technique, to relate defects produced at short time scales with those observed experimentally at much longer time scales. On the other hand we perform in situ TEM experiments of Au irradiated at liquid-nitrogen temperatures, and study the evolution of the produced damage as the temperature is increased to room temperature. We find that some of the defects observed in the MD simulations at short time scales using the TEM image simulation technique have features that resemble those observed in laboratory TEM images of irradiated samples. In situ TEM shows that stacking fault tetrahedra are present at the lowest temperatures and are stable during annealing up to room temperature, while other defect clusters migrate one dimensionally above -100 deg. C. Results are presented here

Modification of photosensing property of CdS–Bi{sub 2}S{sub 3} bi-layer by thermal annealing and swift heavy ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Shaikh, Shaheed U.; Siddiqui, Farha Y. [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India); Singh, Fouran; Kulriya, Pawan K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Phase, D.M. [UGC DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India); Sharma, Ramphal, E-mail: ramphalsharma@yahoo.com [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

2016-02-01

The CdS–Bi{sub 2}S{sub 3} bi-layer thin films have been deposited on Indium Tin Oxide (ITO) glass substrates at room temperature by Chemical Bath Deposition Technique (CBD) and bi-layer thin films were annealed in air atmosphere for 1 h at 250 {sup °}C. The air annealed sample was irradiated using Au{sup 9+} ions at the fluence 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. Effects of Swift Heavy Ion (SHI) irradiation on CdS–Bi{sub 2}S{sub 3} bi-layer thin films were studied. The results are explained on the basis annealing and high electronic excitation, using X-ray diffraction (XRD), Selective Electron Area Diffraction (SEAD), Atomic Force Microscopy (AFM), Raman Spectroscopy, UV spectroscopy and I–V characteristics. The photosensing property after illumination of visible light over the samples is studied. These as-deposited, annealed and irradiated bi-layer thin films are used to sense visible light at room temperature. - Graphical abstract: Schematic illustration of CdS–Bi{sub 2}S{sub 3} bi-layer thin film (a) As-deposited (b) Annealed (c) irradiated sample respectively (d) Model of bi-layer photosensor device (e) Graph of illumination intensity verses photosensitivity. - Highlights: • CdS–Bi{sub 2}S{sub 3} bi-layer thin film prepared at room temperature. • Irradiated using Au{sup 9+} ions at the fluence of 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. • Study of modification induced by irradiations. • Study of Photosensitivity after annealing and irradiation.

Effect of fast neutron irradiation on the thermal and electrical properties of acrylic resin

International Nuclear Information System (INIS)

Madi, N.K.; El-Khatib, A.M.; Kassem, M.E.; Ammar, E.A.

1993-01-01

Infrared technique was used to elucidate the effect of neutron irradiation on the structure of the polymethyl methacrylate (PMMA). It was found that PMMA resists large doses of irradiation at room temperature. The thermo-mechanical and electrical conductivity experiments have been applied to confirm the chemical results. The results show that the physical properties were slightly improved. The observations are correlated with the crystallinity produced by the accumulation of stable radiation defects. (author). 12 refs., 5 figs

Biochemical changes in full fat rice bran stabilized through microwave heating and irradiation treatment

International Nuclear Information System (INIS)

El-Niely, H.F.; Abaullah, M.I.

2007-01-01

The effect of microwave heating and irradiation treatments on proximate composition, lipoxygenase (LOX) activity, free fatty acid (FFA) and fatty acids profile of full fat rice bran were examined. Full fat raw rice bran (FRB) (82.7 g / kg moisture content) was heated in microwave oven at 850 W for up to 4 min or exposed to gamma irradiation up to 25 KGy then packed in polyethylene bags and stored at room temperature for 6 months. Water, protein, fat, ash and crude fiber contents did not change significantly in raw, microwave heated and irradiated samples before and after storage. An exception for this general observation was observed for the moisture content of FRB processed through microwave heating where heating FRB for 4 min dropped the level of moisture to 64.3 g / kg at zero time. Storage of both raw and processed samples had significant (P<0.05) effects on LOX activity. LOX activity of raw samples was significantly increased from its initial value by 43.5% after storage for six months. Microwave heat and irradiated samples showed deactivated LOX and samples exhibited significant changes in LOX activity could be due to treatment dosage. Meanwhile, significant change in LOX activity was observed in processed samples stored for six months. Minor changes were observed due to applied processing methods on FFA and fatty acids composition of full fat rice bran before and after storage. The results suggested that microwave heated or irradiated full fat rice bran packed in polyethylene bags can be stored at room temperature for six months without adverse effect on proximate, fatty acid composition quality and could prevent oxidative and hydrolytic rancidity. However, gamma irradiation treatment at 25 KGy was more effective in this respect. Therefore, it could be concluded that gamma irradiation contributed to optimal processing conditions for FRB stabilization

Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

DEFF Research Database (Denmark)

Henriksen, L.; Johansen, A.; Koch, J.

1968-01-01

Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

The phenomenon of photoreactivation in bacteria E. coli irradiated by ionizing radiation

International Nuclear Information System (INIS)

Myasnik, M.N.; Morozov, I.I.

1977-01-01

Photoreactivation (PR) has been detected after γ-irradiation of various hypersensitive strains of E. coli. Suspensions of cells were 60 Co γ-irradiated in the dark at room temperature, and either pre- or post-illuminated for 30 minutes with the light from daylight fluorescent lamps. Studies of the effects of PR on the survival curves, and of the photoreactivation kinetics for killing, suggested that the increased survival of the γ-irradiated cells of some strains of E. coli after illumination with photoreactivating light, may be the result of true photoenzymatic repair. Comparison of different strains showed that, after γ-irradiation, PR took place only in those strains of E. coli carrying mutations simultaneously in two genes: uvr,rec or uvr,exr. It therefore seems that mutations in genes uvr,rec or uvr,exr determine both PR ability after γ-irradiation and hypersensitivity to UV-light and γ-rays. Possible mechanisms are discussed. (author)

Batch scale strength of garlic by irradiation combined with natural low temperature

International Nuclear Information System (INIS)

Cho, H.O.; Kwon, J.H.; Byun, M.W.

1984-01-01

An attempt was made on the development of a commercial scale storage method of garlic by irradiation. Irradiated garlics with 50, 100 and 150 Gy were stored at natural low temperature storage room (12±6°C, 75-85% RH) and the physicochemical properties during the 10 months storage were investigated. The unirradiated garlic was mostly sprouted after 8 months storage, whereas the sprouting of all irradiated groups was completely inhibited until 10 months storage, The rotting rate and weigh loss of garlic after 10 months storage were reduced by 25 to 54% at 100 Gy irradiation compared with those of an unirradiated group. The moisture content remained relatively constant during the whole storage period. The total sugar content was increased with storage period. Ascorbic acid content was also decreased until 8 months storage but its content was rapidly increased along with sprouting. Garlic was marketable after 10 months storage by 100 Gy irradiation combined with natural low temperature. (author)

Leaching of irradiated CANDU UO2 fuel

International Nuclear Information System (INIS)

Vandergraaf, T.T.; Johnson, L.H.; Lau, D.W.P.

1980-01-01

Irradiated fuel, leached at room temperature with distilled water and with slightly chlorinated river water, releases approx. 4% of its cesium inventory over a comparatively sort period of a few days but releases its actinides and rare earths more slowly. The matrix itself dissolves at a rate conservatively calculated to be less than approx. 2 x 10 -6 g UO 2 /cm 2 day and, with time, the leach rates of the various nuclides approach this value

Neutron irradiation effects on the ductile-brittle transition of ferritic/martensitic steels

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1997-08-01

Ferritic/martensitic steels such as the conventional 9Cr-1MoVNb (Fe-9Cr-1Mo-0.25V-0.06Nb-0.1C) and 12Cr-1MoVW (Fe-12Cr-1Mo-0.25V-0.5W-0.5Ni-0.2C) steels have been considered potential structural materials for future fusion power plants. The major obstacle to their use is embrittlement caused by neutron irradiation. Observations on this irradiation embrittlement is reviewed. Below 425-450{degrees}C, neutron irradiation hardens the steels. Hardening reduces ductility, but the major effect is an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy, as measured by a Charpy impact test. After irradiation, DBTT values can increase to well above room temperature, thus increasing the chances of brittle rather than ductile fracture.

Free Radicals Formation of Irradiated Lyophilized Can-Cellous Human and Bovine Bone

International Nuclear Information System (INIS)

Abbas, Basril; Sudiro, Sutjipto; Hilmy, Nazly

2000-01-01

Radiation sterilization of lyophilized human and bovine bone as allograft and xenograft have been produced and used in orthopaedic practice in Indonesia routinely. It is well known from radio biologic studies that one of the most pronounce effects of ionizing radiation on biologic species produced the free radicals that influence the physico-chemical as well as the mechanical properties of irradiated bone. The aim of our study is to investigate the free radicals formation of irradiated lyophilized cancellous triple A bone (Autolyzed Antigen-Extracted Allograft) produced by Batan Research Tissue Bank in Jakarta. The cancellous triple A were prepared according to AATB (American Association of Tissue Bank) method. Gamma Irradiations was done at doses of 10, 20 and 30 kGy with a dose rate of 7,5 kGy/h at room temperature (30 o C± 2 o C). Measurements of free radicals was done at 24 o C ±1 o C within 30 minutes after irradiational and measurement were continued up to 9 months of storage using a JES-REIX ESR Spectrophotometer (JEOL) with Mn exp. ++ standard. Parameters measured, were the effects of mechanical grinding, water immersion and irradiation dose on free radicals formation in the bone. Results show that the signal area of ESR spectra from irradiated bovine bone of 30 kGy was higher than those of human bone I.e. 1,4 x 10 exp. 7 dan 6,4 x 10 exp. 6 Au (arbitrary unit)/g samples respectively. The signal of ESR spectra increased linearly with increasing dose in the range of 10-30 kGy and it will reduce about 30% caused by water immersion. The ESR signal reduced sharply after 2 days and gradually decreased up to 14 days and then became constant up to 9 months of storage at room temperature. A certain method of crushing can produce free radicals. Key Words: free radical, irradiation, allograft, xenograft, mechanical-grinding

ESR investigation of gamma-irradiated Aspirin

International Nuclear Information System (INIS)

Cozar, O.; Chis, V.; David, L.; Damian, G.; Barbur, I.

1997-01-01

Electron spin resonance spectroscopy was used to investigate the radiation damage in a powder of 2-acetoxybenzoic acid (Aspirin). Three types of radicals occur by γ-irradiation of Aspirin at room temperature. Two of them are result of hydrogen abstraction while the third is produced by hydrogen addition at one of the carbon atoms of the ring. The relative yielding of the free radicals as a function of absorbed dose in the range of 2.4 kGy to 160 kGy is also discussed. (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

Transfer of energy from irradiated crystals to redox reactions: iodide/bromate and nitrite/bromate systems

International Nuclear Information System (INIS)

Arnikar, H.J.; Madhava Rao, B.S.; Bedekar, M.J.

1978-01-01

Earlier it had been shown by the authors that some of the redox reactions, which do not take place at room temperature can be induced by γ radiation. The yields are proportional to the dose. Results reported here show that instead of direct irradiation, the energy stored in irradiated crystals in the form of F and hole centres can be available, in part, in effecting redox reactions. The mechanism of such an energy transfer is discussed with reference to reactions in the I - +BrO 3 - and NO 2 - +BrO 3 - systems due to the addition of irradiated NaCl. (author)

Effects of electron beam irradiation on mechanical properties at low and high temperature of fiber reinforced composites using PEEK as matrix material

International Nuclear Information System (INIS)

Sasuga, Tsuneo; Seguchi, Tadao; Sakai, Hideo; Odajima, Toshikazu; Nakakura, Toshiyuki; Masutani, Masahiro.

1987-11-01

Carbon fiber reinforced composite (PEEK-CF) using polyarylether-ether-ketone (PEEK) as a matrix material was prepared and the electron beam radiation effects on the mechanical properties at low and high temperature and the effects of annealing after irradiation were studied. Cooling down to 77 K, the flexural strength of PEEK-CF increased to about 20 % than that at room temperature. The data of flexural strength for the irradiated specimens showed some scattering, but the strength and modulus at 77 K were changed scarcely up to 120 MGy. The flexural strength and modulus in the unirradiated specimen decreased with increasing of measurement temperature, and the strength at 140 deg C, which is the just below temperature of the glass transition of PEEK, was to 70 % of the value at room temperature. For the irradiated specimens, the strength and modulus increased with dose and the values at 140 deg C for the specimen irradiated with 120 MGy were nearly the same with the unirradiated specimen measured at room temperature. The improvement of mechanical properties at high temperature by irradiation was supported by a viscoelastic measurement in which the glass transition shifted to the higher temperature by the radiation-induced crosslinking. A glass fiber reinforced PEEK composite (PEEK-GF) was prepared and its irradiation effects by electron beam was studied. Unirradiated PEEK-GF showed the same performance with that for GFRP of epoxide resin as matrix material, but by irradiation the flexual strength and modulus decreased with dose. It was revealed that this composite was destroyed by delamination because inter laminar shear strength (ILSS) decreased with dose and analysis of the profile of S-S curve showed typical delamination. Fractoglaphy by electron microscopy supported the delamination which is caused by the lowering of adhesion on interface between the fiber and matrix with increase of dose. (author)

Use of electron spin resonance technique for identifying of irradiated foods

Energy Technology Data Exchange (ETDEWEB)

El-Shiemy, S M E

2008-07-01

The present investigation was carried out to establish the electron spin resonance (ESR) technique for identifying of some irradiated foodstuffs, i.e. dried fruits (fig and raisin), nuts (almond and pistachio) and spices (fennel and thyme). Gamma rays were used as follows: 0, 1, 3 and 5 kGy were given for dried fruits, while 0, 2, 4 and 6 kGy were given for nuts. In addition, 0, 5, 10 and 15 kGy were given for spices. All treatments were stored at room temperature (25{+-}2 degree C) for six months to study the possibility of detecting its irradiation treatment by ESR spectroscopy. The obtained results indicated that ESR signal intensities of all irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation. So, all irradiated samples under investigation could be differentiated from unirradiated ones immediately after irradiation treatment. The decay that occur in free radicals which responsible of ESR signals during storage periods at ambient temperature showed a significant minimize in ESR signal intensities of irradiated samples. Therefore, after six months of ambient storage the detection was easily possible for irradiated dried fig with dose {>=} 3 kGy and for all irradiated raisin and pistachio (shell). Also, it was possible for irradiated fennel with dose {>=} 10 kGy and for irradiated thyme with dose {>=}15 kGy. In contrast, the identification of all irradiated samples of almond (shell as well as edible part) and pistachio (edible part) was impossible after six months of ambient storage.

Use of electron spin resonance technique for identifying of irradiated foods

International Nuclear Information System (INIS)

El-Shiemy, S.M.E

2008-01-01

The present investigation was carried out to establish the electron spin resonance (ESR) technique for identifying of some irradiated foodstuffs, i.e. dried fruits (fig and raisin), nuts (almond and pistachio) and spices (fennel and thyme). Gamma rays were used as follows: 0, 1, 3 and 5 kGy were given for dried fruits, while 0, 2, 4 and 6 kGy were given for nuts. In addition, 0, 5, 10 and 15 kGy were given for spices. All treatments were stored at room temperature (25±2 degree C) for six months to study the possibility of detecting its irradiation treatment by ESR spectroscopy. The obtained results indicated that ESR signal intensities of all irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation. So, all irradiated samples under investigation could be differentiated from unirradiated ones immediately after irradiation treatment. The decay that occur in free radicals which responsible of ESR signals during storage periods at ambient temperature showed a significant minimize in ESR signal intensities of irradiated samples. Therefore, after six months of ambient storage the detection was easily possible for irradiated dried fig with dose ≥ 3 kGy and for all irradiated raisin and pistachio (shell). Also, it was possible for irradiated fennel with dose ≥ 10 kGy and for irradiated thyme with dose ≥15 kGy. In contrast, the identification of all irradiated samples of almond (shell as well as edible part) and pistachio (edible part) was impossible after six months of ambient storage.