International Nuclear Information System (INIS)

The photobiology of mouse melanocyte lines with different pigment genotypes was studied by measuring colony-forming ability after irradiation. The cell lines were wild-type black (melan-a) and the mutants brown (melan-b) and albino (melan-c). Four lamps emitting various UV wavelengths were used. These were germicidal (UVC, 200-280 nm), 82.3% output at 254 nm, TL01 (UVB, 280-320 nm), 64.2% at 310-311 nm, FS20, broadband with peak output at 312 nm and Alisun-S (UVA, 320-400 nm), broadband with peak output at 350-354 nm. Appropriate filtration reduced the contaminating UVC to nonlethal levels for the longer waverange lamps. It is clear from these studies that, in pigment cells, monochromatic results cannot predict polychromatic responses and that cell death from solar irradiations is a complex phenomenon that depends on more than DNA damage. (author).

International Nuclear Information System (INIS)

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens ...

British Library Electronic Table of Contents (United Kingdom)

To test the effect of humidity on the radiation resistance of Deinococcus radiodurans, air-dried cells were irradiated with germicidal 254?nm UV, and simulated environmental UV or ?-radiation and survival was compared to cells in suspension. It was observed that desiccated cells exhibited higher levels of resistance than cells in suspension toward UV or ?-radiation as well as after 85?C heat shock. It was also shown that low relative humidity improves survival during long-term storage of desiccated D. radiodurans cells. It can be concluded that periods or environments in which cells exist in a dehydrated state are beneficial for D. radiodurans? survival exposed to various other stresses.

International Nuclear Information System (INIS)

Spontaneous and ultraviolet-induced changeabilities of wine yeasts from the killer state to sensitive one have been studied. Observed often spontaneous changes of killer and neutral phenotypes under laboratory store conditions as well as high mutation frequency of genetic elements responsible for the killer indication on ultraviolet irradiation testify that often encounterability in nature and in the production of sensitive yeasts is attributed to high frequency of mutation changes of the killer and neutral phenotypes to the sensitive state.

British Library Electronic Table of Contents (United Kingdom)

With conventional heating process, ultraviolet (UV) illumination, and microwave irradiation, we have successfully synthesized UV curable encapsulating adhesives with excellent gas barrier capabilities, good adhesive strength, moderate hardness, and high refractive indices. The experimental results manifest that the physical properties of lab-made encapsulating adhesives are highly dependent on their chemical structures and synthetic procedure. We also discover that the encapsulating adhesive prepared by microwave irradiation (i.e. encapsulating adhesive VI-MW) exhibits better adhesive strength and higher gas resistance than those prepared by conventional heating process and UV illumination. Furthermore, encapsulating adhesive VI-MW has also been applied for the package of organic light emi...

International Nuclear Information System (INIS)

The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 ...

International Nuclear Information System (INIS)

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

Science.gov (United States)

uv irradiation (365 nm) of air-saturated methanol solutions of 20 drugs absorbing in the 300 to 400 nm region gave rise to oxygen uptake, as determined with a polarographic oxygen electrode. The drugs were tested for photosensitizing capability by either a Type I (free radical) or a Type II (single molecular oxygen) mechanism. This testing was done by the inclusion of either acrylamide or 2,5-dimethylfuran in the irradiated drug solution, with observation of the subsequent polymerization or oxidation, respectively. Phenothiazine and thiazide derivatives appear capable of photosensitization by both mechanisms; promethazine, trifluoperazine, and furosemide show relatively high reactivity. Diazepam (weak), hexachlorophene, aminacrine, pyrilamine, tetracycline, demeclocyline, quinine, and anthracene (strong) react only by a Type II mechanism, with a photosensitizing efficiency increasing in the order given. A correlation appears to exist with ...

International Nuclear Information System (INIS)

The water soluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When ...

Science.gov (United States)

Oxide charge on the sidewalls of SiO{sub 2} embedded silicon wires with 20x20 nm{sup 2} cross section is shown to influence the Schottky barrier height for Pd{sub 2}Si/Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3 eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15 eV and the hole barrier correspondingly increases by about the same amount. The phenomenon is explained by assuming an oxide charge density in the range of 10{sup 12} cm{sup -2}.

Science.gov (United States)

Scrotal skin of black Long-Evans rats and human thigh skin were maintained in vitro as organ cultures for as long as 14 days, and examined histologically using the combined skin splitting and Dopa techniques. Selected rat skin cultures received testosterone in the culture medium and/or were irradiated with ultraviolet light (290 to 320 nm uvl). With increased time in culture, scrotal melanocytes round up and there is an increase in epidermal pigmentation. Human skin behaves similarly; after eight days in vitro human melanocytes also become rounded, but remain strongly Dopa-positive. Addition of exogenous testosterone to cultured rat skin maintains dendritic morphology of melanocytes, but cell body size is still reduced. uvl irradiation stimulates melanocytes in rat skin cultures, maintaining their dendritic morphology and increasing epidermal and dermal pigmentation. Cultured skin receiving both uvl and testosterone ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even ...

International Nuclear Information System (INIS)

We used the recuperation effect (see also 'Recuperation of infrared stimulated luminescence of feldspars' in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a 'double-bleach recuperation' experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of #approx#1% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse order (1st GL, 2nd IR). These ...

Energy Technology Data Exchange (ETDEWEB)

A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single polypeptide of this enzyme. This polypeptide has a molecular mass of 37 kilodaltons and an isoelectric point of 5.4. Ultraviolet (UV) irradiation was necessary for photolabeling to occur. In addition, no labeling occurred when the probe was prephotolyzed or when the enzyme was inactivated. Furthermore, photolabeling of the enzyme could be decreased by preincubation with natural substrates. To provide evidence that the radiolabeled polypeptide forms a part of the domain of the nucleoside triphosphate binding site, experiments were performed using unlabeled 8-N3ATP. Although this unlabeled analogue ...

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

A series of measurements of O_3 yield in nuclear induced O_2 and O_2-SF_6 discharges created by bombardment with energetic particles from the "1"0B(n,#alpha#)"7Li reaction are reported. Continuous irradiation at dose ratios of 10"1"5-10"1"7 eV.cm"-"3.s"-"1 and pulsed irradiation (approx.10 ms FWHM) at a peak dose rate of approx.10"2"0 eV.cm"-"3.s"-"1 were conducted. At the lower dose rates, SF_6 addition generally increased the ozone yield, which at the high dose rates, SF_6 addition decreased the observed ozone concentration. A numerical model was developed and applied to experimental conditions. The steady-state ozone concentration was found to be limited by the reaction O_3"- + O_3 #-># 2O_2 + O_2"-. A simplified analytical model of steady-state conditions was used to predict model sensitivity to various parameters. In addition to dose rate effects, pressure and temperature effect on ozone production were discussed. The present study was ...

Science.gov (United States)

in a KDP crystal fed with red light from a Q-s_tched ruby laser. One reason for interest in holograms made with ultraviolet ...

Science.gov (United States)

instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...

International Nuclear Information System (INIS)

Cockayne syndrome (CS) is a rare autosomal recessive disease, which shows diverse clinical symptoms such as photosensitivity, severe mental retardation and developmental defects. CS cells are hypersensitive to killing by ultraviolet (UV)-irradiation and defective in transcription-coupled repair. Two genetic complementation groups in CS (CS-A and CS-B) have been identified. We analyzed mutations of the CSA gene in 5 CS-A patients and identified 3 types of mutations. Four unrelated CS-A patients (CS2OS, CS2AW, Nps2 and CS2SE) had a deletion including exon 4, suggesting that there is a founder effect on the CSA mutation in Japanese CS-A patients. Patient CS2SE was a compound heterozygote for this deletion and an amino acid substitution at the 106th glutamine to proline (Q106P) in the WD-40 repeat motif of the CSA protein, which resulted in a defective nucleotide excision repair. Patient Mps1 had a large deletion in the upstream region including ...

Energy Technology Data Exchange (ETDEWEB)

Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish ...

Energy Technology Data Exchange (ETDEWEB)

A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.

Energy Technology Data Exchange (ETDEWEB)

The absolute absorption of ozone in the midinfrared has been measured relative to 253.7-nm ultraviolet absorption to an accuracy of 1% using a Bruker Fourier transform spectrometer. These new results agree with previous measurements by diode laser measurements after the latter are corrected for more recent infrared calculations and ultraviolet cross sections. They also agree with a determination based on refractive index measurements in the infrared. 16 refs., 4 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Energy Technology Data Exchange (ETDEWEB)

Tetracycline is an antibiotic that absorbs ultraviolet light at 355 nm and preferentially binds to atherosclerotic plaque both in vitro and in vivo. Tetracycline-treated human cadaveric aorta was compared with untreated aorta using several techniques: absorptive spectrophotometry; and tissue uptake of radiolabeled tetracycline, which showed 4-fold greater uptake by atheroma than by normal vessel. In addition, intravenous tetracycline administered to patients undergoing vascular surgery demonstrated characteristic fluorescence in surgically excised diseased arteries. Because of tetracycline's unique properties, the authors exposed tetracycline-treated and untreated aorta to ultraviolet laser radiation at a wavelength of 355 nm. They found enhanced ablation of tetracycline-treated atheroma compared with untreated atheroma. The plaque ablation caused by ultraviolet laser radiation was twice as extensive in ...

Energy Technology Data Exchange (ETDEWEB)

Since 1979, scientists and engineers at the Los Alamos National Laboratory have designed, constructed, and operated a radio-frequency (RF) linac free-electron laser (FEL) at wavelengths from 9 to 45 /mu/m. Coupled with success of other research centers investigating wavelengths from the visible to far-infrared, Los Alamos is now proposing a vacuum-ultraviolet and soft x-ray (referred to henceforth as extreme ultraviolet, (XUV)) FEL oscillator/Self-Amplified Spontaneous Emission amplifier with beam energies ranging from 100 MeV to 1 GeV. This paper will focus on the first milestone of the proposed Los Alamos XUV project, i.e., a 250-MeV linac with approximately 50 mA of average current, producing photons with wavelengths below 1000 /angstrom/. 3 refs., 3 figs.

Science.gov (United States)

Oct 2, 2007 ... The Payload combines some of the most sensitive particle sensors .... provide state-of-the-art measurements of incoming x-ray, ultraviolet, .... It will be launched into a low-Earth orbit on a Delta 7320 rocket in September 2004. ...

UK PubMed Central (United Kingdom)

Experiments on Xanthium leaf discs were carried out to determine whether concomitant photoreactivation could be detected and if so, to compare its effects with photoreactivation due...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The ultraviolet photoelectron spectra of benzoic acid and 20 of its derivatives are presented. The low-energy regions of these spectra are deconvoluted and assigned using chemical substitution effects. 5 figures, 3 tables.

International Nuclear Information System (INIS)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant #tau# obtained from the curve fitting represents the ...

UK PubMed Central (United Kingdom)

Ultraviolet (UV) screens are increasingly used as a result of growing concern about UV radiation and skin cancer; they are also added to cosmetics and other products for light stability. Recent data...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This work deals with a rational vision of stratospheric ozone including the threats on ozone layer, the verifications and the fears. After a recalling on the ozone layer history, the authors treats the question of the ultraviolets particularly the beneficial effects. Then an explanation of the ozone layer decrease is given. (O.L.). 29 refs., 6 figs.

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

International Nuclear Information System (INIS)

... carrier-free isotopes hafnium compounds irradiation protons solvent extraction

CERN Document Server

We present the results of a search for Extreme Ultraviolet emission in A4059, a cluster with an X-ray emitting cluster gas. Our analysis of Extreme Ultraviolet Explorer (EUVE) Deep Survey observations of this cluster shows that it is associated with diffuse EUV emission. Outside the central 2 arcmin radius the entire EUV emission detected is explained by the low energy tail of the X-ray emitting gas. Within the central 2 arcmin region of the cluster we find a deficit of EUV emission compared to that expected from the X-ray gas. This flux deficit is discussed in the context of the cluster's cooling flow. The results derived for A4059 are compared to EUVE results obtained for other clusters such as Coma, Virgo, A1795, and A2199. As part of the study we have carried out a detailed investigation of the stability of the EUVE Deep Survey detector background. Based on long integrations of blank sky over 27 months we disprove claims of substantial time ...

British Library Electronic Table of Contents (United Kingdom)

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 ?C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.

CERN Document Server

The auroras on Jupiter and Saturn can be studied with a high sensitivity and resolution by the Hubble Space Telescope (HST) ultraviolet (UV) and far-ultraviolet (FUV) Space Telescope spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments. We present results of automatic detection and segmentation of Jupiter's auroral emissions as observed by HST ACS instrument with VOronoi Image SEgmentation (VOISE). VOISE is a dynamic algorithm for partitioning the underlying pixel grid of an image into regions according to a prescribed homogeneity criterion. The algorithm consists of an iterative procedure that dynamically constructs a tessellation of the image plane based on a Voronoi Diagram, until the intensity of the underlying image within each region is classified as homogeneous. The computed tessellations allow the extraction of quantitative information about the auroral features such as mean intensity, latitudinal and longitudinal ...

CERN Document Server

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of H I and high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.

Energy Technology Data Exchange (ETDEWEB)

A composition and method for encapsulating a photovoltaic device which minimizes discoloration of the encapsulant. The composition includes an ethylene-vinyl acetate encapsulant, a curing agent, an optional ultraviolet light stabilizer, and/or an optional antioxidant. The curing agent is preferably 1,1-di-(t-butylperoxy)-3,3,5-trimethylcyclohexane; the ultraviolet light stabilizer is bis-(N-octyloxy-tetramethyl) piperidinyl sebacate and the antioxidant is selected from the group consisting of tris (2,4-di-tert-butylphenyl) phosphite, tetrakis methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, and 2,2'-ethylidene bis(4,6-di-t-butylphenyl) fluorophosponite. The composition is applied to a solar cell then cured. The cured product contains a minimal concentration of curing-generated chromophores and resists UV-induced degradation.

International Nuclear Information System (INIS)

Irradiation response on the tensile properties of 9Cr-2W steels has been investigated following FFTF/MOTA irradiations at temperatures between 646 and 873 K up to doses between 10 and 59 dpa. The largest irradiation hardening accompanied by the largest decrease in the elongation is observed for the specimens irradiated at 646 K at doses between 10 and 15 dpa. The irradiation hardening appears to saturate at a dose of around 10 dpa at the irradiation temperature. No hardening but softening was observed in the specimens irradiated at above 703 K to doses of 40 and 59 dpa. Microstructural observation by transmission electron microscope (TEM) revealed that the dislocation loops with the a left angle 100 right angle type Burgers vector and small precipitates which were identified to be M_6C type carbides existed after the ...

Energy Technology Data Exchange (ETDEWEB)

This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.

UK PubMed Central (United Kingdom)

Growth at increasing continuous irradiance (at high nutrient nitrate) and nutrient nitrate concentrations (at high continuous irradiance) furnished increases in the in vivo and in...Full Text Available

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The effects of #alpha# particle irradiation on a passive film formed on a 304 type stainless steel are studied in situ. The experimental arrangement minimizes the radiolysis effects due to the electrolyte. Under irradiation, a modification of the electronic structure of the oxide layers is revealed by photo-electrochemistry and impedance measurements. The influence of irradiation on the corrosion resistance of the passive film is investigated. Comparing the rest potential and the breakdown potential respectively under and without irradiation, a drop in the passivity range under irradiation is shown. this is interpreted as a decrease in the corrosion resistance. (author).

International Nuclear Information System (INIS)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

UK PubMed Central (United Kingdom)

Epidermal gamma delta T cells (γδ T) and Langerhans cells (LC) are immune cells altered by exposure to ultraviolet radiation (UVB), a powerful stressor resulting in immune suppression....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.

Science.gov (United States)

The non-invasiveness of autofluorescence technology may reduce sampling error and time delay for histopathology diagnosis. We establish biophotonic methods and guidelines to visualize and interpret early epithelial tissue changes that signify disease. Flexible and rigid fiber endomicroscopy instrumentation design parameters feasible for translation towards clinical use are in development.

International Science & Technology Center (ISTC)

Experimental and Theoretical Study of the Residual Nuclide Production in 40-2600 MeV Proton-Irradiated Thin Targets of ADS Basic Materials

Energy Technology Data Exchange (ETDEWEB)

Radiation Damage Calculations for the FUBR and BEATRIX Irradiations of Lithium Compunds in EBR-II and FFTF

Science.gov (United States)

Dislocation priming measurements were performed in the kHz range in ASARCO copper. The samples and irradiation facilities are constructed so as to allow successive irradiation of samples both with electrons and gamma rays. The gamma rays were produced by stopping 2.8-MeV electrons in a gold target. The change of the type of irradiation could be achieved without any handling of the sample. Thus it is possible to detect rather small differences between the two types of irradiation. Recovery experiments at 400 deg K after 75 deg K irradiation and pinning rates during irradiation at 400 deg K and 75 deg K were made. (GE)

CERN Document Server

Determination of absorbed dose in a patient irradiated by beams of x or gamma rays in radiotherapy procedures

International Nuclear Information System (INIS)

Spices and packaging materials were exposed to gamma irradiation at a dose of 10 KGy. Luncheon was prepared with irradiated or non-irradiated spices. Prepared luncheon was packaged in irradiated or non-irradiated packaging materials. Packaged luncheon was treated with 2 KGy. Treated and untreated packaged luncheon were kept in a refrigerator (1-4 Centigrade) for 12 months. Microbiological, nutritive and chemical characteristics of luncheon were evaluated after processing and during storage; whereas, sensory quality was evaluated only after irradiation. Gamma irradiation decreased the microorganisms counts of spices, packaging materials and packed luncheon and increased the shelf-life of packaged luncheon products. No major differences in moisture, protein, fat, ph value, total acidity, lipid peroxide and volatile basic nitrogen were observed ...

Energy Technology Data Exchange (ETDEWEB)

Short communication. 2 figs.

International Nuclear Information System (INIS)

... radiation effects human populations low dose irradiation neoplasms radiation

Energy Technology Data Exchange (ETDEWEB)

A summary is presented of research being carried out in Thailand on the preparation of irradiation-impregnated wood.

Energy Technology Data Exchange (ETDEWEB)

The potential market for irradiated chicken breasts was investigated using a mail survey and a retail trial. Results from the mail survey suggested a significantly higher level of acceptability of irradiated chicken than did the retail trial. A subsequent market experiment involving actual purchases showed levels of acceptability similar to that of the mail survey when similar information about food irradiation was provided.

Energy Technology Data Exchange (ETDEWEB)

Electron spin resonance (ESR) dosimetry of irradiated chicken legs is based on the additive dose or the calibration curve methods. In both cases the practical assumption is made that the behaviour of the chicken bone does not depend on factors such as temperature during irradiation, storage conditions and dose rate. So the aim of the present work was to investigate to what extent the above mentioned factors could influence the post-irradiation dose assessment using the ESR technique. (author).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

A brief article examines the controversy over food irradiation regarding the wholesomeness of irradiated food, its microbiological safety, loss of vitamins and changes in flavour. The benefits of food irradiation are also outlined including the destruction of certain food-borne pathogens and the prolongation of the shelf-life of food by killing pests and delaying the deterioration process. (UK).

International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

Full Text Available

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Short communication.

International Nuclear Information System (INIS)

Effects of #gamma#-irradiation on synthetic polymers and paper used as packaging materials for irradiated food have been studied by NMR. Polystyrene, polybutadiene and some copolymers were studied before and after the #gamma#-irradiation treatment and in the presence or absence of antioxidants and stabilisers. In the absence of additives, the effect of #gamma#-irradiation on polystyrene is negligible even irradiating at high doses. In turn, the role of antioxidants and stabilisers is crucial in polybutadiene and butadiene-containing copolymers. Wood pulp paper was also studied by NMR. Preliminary measurements on #gamma#-irradiated wood pulp sheets show a shortening in the T_2 relaxation time component due to the bound water, i.e. some of the bound water is lost. (author)

International Nuclear Information System (INIS)

The irradiation behavior of Li_2TiO_3 under a fusion reactor environment was simulated by simultaneous irradiation of Li_2TiO_3 by the triple ion beams and the respective single ion beams of O"2"+, He"+ and H"+. The microstructural changes in Li_2TiO_3 caused by the irradiation were measured by Raman spectroscopy and FT-IR photoacoustic spectroscopy. The results suggest that the formation of TiO_2 due to displacements by irradiation occurs, and the irradiation defects generated by irradiation trap hydrogen and increase the amount of hydroxyl near the surface. Such phenomena are believed to significantly affect the chemical form of the released tritium and the tritium inventory in the breeding materials of a fusion reactor.

International Nuclear Information System (INIS)

The facilities in the Institute for Nuclear Research at Pitesti allow the testing, handling and examination of nuclear fuel and irradiated materials. The most important facilities are the TRIGA Steady State Research and Material Test Reactor and the Post-Irradiation Examination Laboratory (PIEL). The purpose of this work is to determine by post-irradiation examination, the behavior of CANDU fuel, irradiated in 14 MW TRIGA reactor. The fuel was irradiated in power ramp conditions. The results of post-irradiation examination are: - Visual inspection and photography of the outer appearance of sheath; - Profilometry (diameter, bending, ovality) and length measuring; - Determination of axial and radial distribution of the fusion products activity by gamma scanning and tomography; - Microstructural characterization by metallographic and ceramographic analyzes; - ...

Energy Technology Data Exchange (ETDEWEB)

Influence of gamma irradiation and storage on the microbial load, chemical and sensory quality of chicken kabab was investigated. Chicken kabab was treated with 0, 2, 4 or 6 kGy doses of gamma irradiation. Treated and untreated samples were kept in a refrigerator (1-4 deg. C). Microbiological, chemical and sensory characteristics of chicken kabab were evaluated at 0-5 months of storage. Gamma irradiation decreased the microbial load and increased the shelf-life of chicken kabab. Irradiation did not influence the major constituents of chicken kabab (moisture, protein and fats). No significant differences (p>0.05) were observed for total acidity between non-irradiated (control) and irradiated chicken kabab. Thiobarbitric acid (TBA) values (expressed as mg malonaldehyde (MDA)/kg chicken kabab) and volatile basic nitrogen (VBN) in chicken kabab were not ...

British Library Electronic Table of Contents (United Kingdom)

The mechanism of abrupt increase of the giant magneto impedance (GMI) ratio in the ion irradiated Co-based amorphous ribbon has been investigated. The grazing incident X-ray diffraction and transmission electron microscope were used to characterize the samples before and after ion irradiation. The GMI-ratio considerably increased in the ion irradiated samples and the GMI response showed strong dependence on the driving frequencies. The Barkhausen noise (BN) signals are increased for the Ar ion irradiated sample with dose of 1x10^1^7 ion/cm^2. The results are interpreted in terms of GMI variation associated with domain wall dynamics.

International Nuclear Information System (INIS)

The most important and difficult part of materials research for fusion reactor is realized to be irradiation studies of fusion reactor materials. Irradiation studies of fusion reactor materials utilizing FFTF/MOTA, as one of Japan/U.S.A. Fusion Collaboration Programs, have important role to establish fundamental understanding of heavy irradiation effects on materials behavior and properties and to develop methods and technologies for advanced irradiation studies under fusion reactor environment. This paper briefly reviews the history, the state of the art, and the future of the FFTF/MOTA program. (author).

International Nuclear Information System (INIS)

The nature of radicals in wood irradiated in vacuum was studied by ESR method. The decay rate of radicals changes in three temperature ranges. Long-lived radicals are very stable at 298"0K, at which the wood-plastics composite has often been studied. The number of radicals formed by irradiations shows fairly good agreement with the total number of radicals in each isolated wood component. The graft copolymerization of MMA to irradiated wood was also studied by means of ESR, and it was found that PMMA propagating radicals are formed in irradiated wood. These radicals are probably formed by the result of graft copolymerization of MMA of wood. (auth.).

International Nuclear Information System (INIS)

Ultraviolet (UV) upconversion (UC) luminescence in Yb3+/Er3+-codoped yttrium oxide (Y2O3) nanocrystals can be enhanced by orders of magnitude via tridoping further with Li+ ions under diode laser excitation of 970 nm. Sensitized three-photon UC radiations at 390 and 409 nm, corresponding to the 4G11/2?4I15/2 and 4H9/2?4I15/2 of Er3+ ions, respectively, present an enhancement time of about 33 times, which is larger than the 24 times enhancement for the UC green radiation. The UV UC radiation at 320 nm that corresponds to the 2P3/2?4I15/2 of Er3+ ions has also been greatly enhanced. Theoretical calculations interpret that all the observed enhancement times of UV UC radiations arise from the prolonged lifetimes of their intermediate states.

International Nuclear Information System (INIS)

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O_3) in the Earth's atmosphere is estimated to be about 4.7 x 10"3"7 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 10"3"1 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time #approx# 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O_2 (leading to production of atomic oxygen, which can combine with O_2 to form O_3) than in ozone ...

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Marmesin was isolated from the medicinal plant, Afraegle paniculata. Its cytotoxicity and mutagenicity in Chinese hamster V79 cells when sensitized to near ultraviolet (NUV) and long wavelength ultraviolet light or black light (BL) were assayed. Marmesin was extremely cytotoxic in the dark. This cytotoxicity was photoenhanced in NUV and BL; the photoenhanced lethality being higher in NUV than in BL. The LD/sub 50/ of marmesin under NUV and BL photosensitization were 0.002 ..mu..M and (0.012 ..mu..M), respectively. In the absence of NUV and BL, marmesin's LD/sub 50/ was 0.013 ..mu..M.NUV and BL without marmesin were not significantly cytotoxic at the fluence rates of 0.29 W/m/sup 2/ and 4.2 W/m/sup 2/, respectively, for up to 20 min. In contrast to the observed high cytotoxicity of marmesin, its mutagenicity at the HGPRT locus (Asub(z)Gsup(r)) was weak. The implication of this result in the high incidence of skin cancer in Nigeria in ...

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Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent ...

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Nanocrystalline ZnO films were fabricated via a simple method involving the oxidation of Zn films at a remarkably low temperature of 380 C. X-ray diffraction study confirmed that the Zn films were completely oxidized even at the low temperature of 380 C and the ZnO films fabricated were of polycrystalline wurtzite structure. Room temperature optical pumping using a frequency-quintupled Q-switched Nd:YAG laser ({lambda}=213 nm) exhibited that sharp peaks at around 3.12 eV emerged above excitation powers of {proportional_to}7 MW/cm{sup 2}, demonstrating lasing in the ZnO films. These results represent that the process is a simple, promising approach for fabricating ZnO of sufficient optical performance for use as ultraviolet (UV) light emitters and an alternative UV laser source; both are key components in short-wavelength photonic devices. (orig.)

CERN Document Server

We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is dominated by numerous, narrow H2 lines fluoresced by H I Ly-alpha, which were not detected in any of the numerous observations of Mira B by the International Ultraviolet Explorer (IUE). The high temperature lines detected by IUE (e.g., C IV 1550) still exist in the STIS spectrum but with dramatically lower fluxes. The continuum fluxes in the STIS spectra are also much lower, being more than an order of magnitude lower than ever observed by IUE, and also an order of magnitude lower than fluxes observed in more recent HST Faint Object Camera objective prism spectra from 1995. Thus, the accretion rate onto Mira ...

International Nuclear Information System (INIS)

Assessments of the hardening and embrittlement of pressure vessel steels and welds as a function of neutron dose use trend curves derived from surveillance programs and accelerated irradiation data. A temperature dependent factor is incorporated for assessing vessel locations operating at different temperatures. As hardening and embrittlement arise from the sum of matrix damage and copper impurity precipitation, the influence of irradiation temperature on each process needs to be established. For irradiations performed below #approx# 300 C recent data shows that the dose-dependent growth of copper precipitates ceases at a mean diameter of about 2 nm that also corresponds to peak hardening and embrittlement by copper. For doses beyond this peak copper dose the property-dependence on irradiation temperature can be identified with that of matrix damage alone. An analysis of several experiments on plate ...

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In this study, free electron laser (FEL) with selective wavelength was used to induce structure changes of biomolecules, which were characterized by FTIR spectroscopy. For understanding of the interactions between FEL and biomolecules as well as biological tissues, the biomolecules investigated are ATP, ADP, AMP, t-RNA, D-ribose and the complex of SmCl_3-D-ribose. Their FTIR spectra before and after irradiation of FEL show molecular structure variations of the samples after irradiation of FEL, especially the rearrangement of their hydrogen bond networks. Along with the various irradiation wavelengths, irradiation time and molecular structures, the changes after irradiation are different for these molecules. In the FTIR spectra after irradiation, the phenomenon that the bands split into several peaks indicates the existence of several structures, conformations ...

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Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon ...

International Nuclear Information System (INIS)

Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting

CERN Document Server

The Drell-Yan mechanism for the production of lepton pairs is one of the most basic processes for physics studies at hadron colliders. It is therefore important to have accurate theoretical predictions. In this work we compute the two-loop virtual mixed QCD x QED corrections to Drell-Yan production. We evaluate the Feynman diagrams by decomposing the amplitudes into a set of known master integrals and their coefficients, which allows us to derive an analytical result. We also perform a detailed study of the ultraviolet and infrared structure of the two-loop amplitude and the corresponding poles in epsilon.

British Library Electronic Table of Contents (United Kingdom)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

CERN Document Server

In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture, while the growth and the saturation of the defects are conditioned by their concurrent annealing due to reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and tested on experimental data.

International Nuclear Information System (INIS)

We studied the optimum plasma conditions that are required for efficient high-order harmonic generation in platinum plume. Harmonics up to the 49th order (?=16.32 nm) are analyzed under various conditions of laser-plasma interaction. Time-resolved ultraviolet spectra of platinum plasma at both optimum and nonoptimum conditions of harmonic generation are presented. We calculated the ionization states of the plasma, free electron density, and singly charged ion density at different prepulse intensities and compared them with experimental results.

Science.gov (United States)

We explore autofluorescence endomicroscopy as a potential tool for real-time visualization of epithelial tissue microstructure and organization in a clinical setting. The design parameters are explored using two experimental systems--an Olympus Medical Systems Corp. stand-alone clinical prototype probe, and a custom built bench-top rigid fiber conduit prototype. Both systems entail ultraviolet excitation at 266 nm and/or 325 nm using compact laser sources. Preliminary results using ex vivo animal and human tissue specimens suggest that this technology can be translated toward in vivo application to address the need for real-time histology.

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Enzyme-linked Immunosorbent assay systems for the identification of irradiated egg, pork and chicken was developed. Eggs were irradiated in their shells to 0.5{approx}7kGy. Pork was irradiated to 0.5{approx}3kGy and chicken irradiated to 0.5kGy{approx}5kGy. The most sensitive proteins to irradiation were screened by SDS-PAGE and purified. Ovalbumin from egg, salt soluble protein(p) from pork, and salt soluble protein(c) from chicken showed the most sensitivity to irradiation. To investigate for a practical use in identifying of irradiated egg, pork and chicken, competitive ELISA was performed. The binding activity of ovalbumin to anti-ovalbumin IgG was reduced in a dose-dependent manner by irradiating up to 7kGy, and considerably lowered after irradiating at 7kGy. The concentration of 50% inhibition ...

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To get a considerable reduction of the radiotoxicity due to americium, a thermal neutron fluence of 2.10{sup 22} cm{sup -2} or a fast neutron fluence of 2.10{sup 24} cm{sup -2} is required. Irradiation in a thermal neutron flux leads to lower masses of {sup 234}U and precursors and of {sup 237}Np and precursors, but to higher curium masses and much higher neutron emission rates than irradiation in a fast neutron flux. Therefore, irradiation in a fast neutron flux has preference when multiple recycling is adopted. When once-through burning is applied, irradiation in a thermal neutron flux can be applied. Then irradiation in a heavy water reactor (HWR) has preference above irradiation in a PWR or in a high temperature gas-cooled reactor (HTGR). (authors) 4 refs.

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The project was designed to solve the infra structural problem required for commercialization of food irradiation. In improvement of physical properties of corn starch, gamma irradiation was effective for increasing glucose productivity and for substituting traditional modified starches (acid modified starch, oxidized starch). In immobilization of microorganisms, the mass production method of natural red pigment was developed by using immobilized mold pellets. In Korean medicinal plants, 10 kGy gamma irradiation was effective for improving sanitary quality and increasing extraction yield. In evaluation of wholesomeness, gamma irradiated red ginseng could be safe on the genotoxic point of view. And also, six items of irradiated foods approved for human consumption from Korea ministry of health and welfare in May 19, 1995. 30 figs, 20 tabs, 54 refs. (Author).

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Thermoluminescence of inorganic dust extract from herbs and spices has been demonstrated to be a useful method to discriminate irradiated food products as well as to estimate the total dose exposure. The time evolution of infrared stimulated luminescence has been systematically investigated in potassium feldspar and albite minerals subjected to different doses of gamma irradiation (ranging from 0 to 8 kGy). Experimental results reveal a 300-600 nm signal which is greatly intensified for irradiated samples, following the same irradiation dose dependence observed in thermoluminescence. The luminescence intensity disappears after few seconds of illumination, following a time evolution which is proportional to (1 + Bt){sup -P}. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)

International Nuclear Information System (INIS)

This discussion paper has two goals: first, to raise public awareness of food irradiation, an emerging technology in which Canada has the potential to build a new industry, mainly oriented to promising overseas markets; and second, to help build consensus among government and private sector decision makers about what has to be done to realize the domestic and export potential. The following pages discuss the potential of food irradiation; indicate how food is irradiated; outline the uses of food irradiation; examine questions of the safety of the equipment and both the safety and nutritional value of irradiated food; look at international commercial developments; assess the current and emerging domestic scene; and finally, draw some conclusions and offer suggestions for action.

International Nuclear Information System (INIS)

Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.

International Nuclear Information System (INIS)

Irradiation processing of food in the prepackaged form may affect chemical and physical properties of the plastic packaging materials. The effect of #gamma#-irradiation doses (2.5-10.0 kGy) on polypropylene (PP)-based retortable food packaging materials, were investigated using Fourier transform infrared (FTIR) spectroscopic analysis, which revealed the changes happening to these materials after irradiation. The mechanical properties decreased with irradiation while oxygen transmission rate (OTR) was not affected significantly. Colour measurement indicated that Nylon 6 containing multilayer films became yellowish after irradiation. Thermal characterization revealed the changes in percentage crystallinity.

International Nuclear Information System (INIS)

In this study, the degrees of destruction of hemoglobin irradiated in atmospheres of air and argon were compared. Hemoglobin preparations were irradiated in the forms: oxyhemoglobin (HbO_2) deoxyhemoglobin (Hb"2"+) and methemoglobin (MetHb) applying doses of 0.5 to 5 Mrad. The degree of hemoglobin destruction was estimate on the basis of changes in the values of the absorption coefficient at the Soret band, the absorption ratio A_5_0_5/A_5_6_3 determined after conversion of irradiated preparations into MetHb, absorption coefficinets for pyridine hemochromogen obtained from irradiated preparations, and changes in parameters characterizing the hemoglobin oxygenation reaction (log p/sub 1/2/O_2 and the Hill n coefficient). The calculated oxygen enhancement ratios S were generally higher than 1 for the parameters estimated. This indicates that the presence of oxygen during irradiation ...

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As part of a combined study of the responses of the mouse adrenal gland and kidney to X-irradiation, the weight of adrenal glands, the relative volumes of the cortex and medulla and the aldosterone output were measured at predetermined times after irradiation of the left organs only.

International Nuclear Information System (INIS)

The formation of porous structures of nanometre size (nanoporous structures) on germanium (Ge) surfaces by focused ion beam (FIB) irradiations was investigated using various FIB conditions such as ion species, irradiation energies, total fluences, fluence rates, and incident angles. FIB-irradiated regions were observed using a scanning electron microscope and an atomic force microscope. It is found that, using a focused Ga ion beam (Ga FIB) at an energy of 100 keV, the irradiated Ge surface swelled up to ion fluence of 2 x 10"1"7 cm"-"2 with nanoporous structures and then was etched for larger fluences. The shape of swollen nanoporous structures depended on the fluence rate and the incident angle of the Ga FIB. However, such porous structures were observed neither for low-energy (15-30 keV) FIB irradiations using Si and Au ions nor for high-energy (200 keV), heavy ion (Au) ...

UK PubMed Central (United Kingdom)

In view of poor local control rates obtained with standard treatment, intraoperative radiation (IORT) using electrons was combined with external beam irradiation and surgical resection, with or without...Full Text Available

International Nuclear Information System (INIS)

Neutron irradiation embrittlement of reactor pressure vessel (RPV) steels is one of the critical issues on aging management for long term operation of nuclear power plants. Mechanistic understanding of embrittlement is a key to accurate prediction of embrittlement, especially after long term operation where the mechanical test data are sparse. Since matrix hardening is the source of the embrittlement, we focus on matrix hardening of A533B bainitic pressure vessel steel. Bainitic matrix is composed of lath structure made by ferrite and carbides, therefore it is important to understand how this structure affects hardening behavior, and to understand irradiation response of each phase. As the typical dimension of lath structure of A533B is about one micron, nanoindentation technique is suitable for the estimation of hardening of each phase. MV ion accelerators were used for controlled irradiation because MeV ion ...

International Nuclear Information System (INIS)

This experiment was done to determine the effects of irradiation on the physical properties of three kinds of laminated packaging materials, i.e. polypropylene-polypropylene, polypropylene-polyethylene, polyester-polyethylene. Observations were made on pinhole production, leakage, oil resistance, resistance against insect penetration, colour, odour tensile strength, elongation at break, seal strength and tear resistance. The samples were irradiated with doses of 0, 5 and 10 kGy, then stored at room temperature and examined after 0, 3, 6 and 12 months of storage. The results showed that irradiation doses up to 10 kGy, as well as storage up to 12 months, did not create pinholes, or leakage in pouches prepared from laminated films. The resistance of the films to oil and insect penetration, the colour, and the odour were also unchanged. Both irradiation and storage treatments had a significant effect on ...

International Nuclear Information System (INIS)

Tensile properties of reduced-activation 10Cr-30Mn austenitic steels with carbon levels from 0.003 to 0.55% were investigated over the temperature range from room temperature to 873 K after neutron irradiation in the Japan Materials Testing Reactor at 573 K to 8.5x10"2"2 n/m"2. Irradiation-induced increase in yield stress increased significantly with carbon concentration up to about 0.1% and it was constant above 0.1% carbon. A high density of dislocation loops with small (below 10 nm) and large (20-30 nm) sizes formed during irradiation. The high density, small loops caused a large irradiation hardening, while the large loops contributed only slightly to irradiation hardening. It was considered that carbon atoms formed the small loops together with irradiation defects. The deformation channeling was observed in the irradiated high carbon ...

UK PubMed Central (United Kingdom)

A nonmammalian test system for germ-cell mutagenesis has been developed by using the Japanese medaka fish. We describe a system for detecting DNA alterations in F1 progeny descended from the gamma-irradiated...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Initial results obtained with a Monte Carlo computer program designed to link initial physical events in irradiated liquid water with subsequent chemical and biological events are presented. 10 refs., 4 figs., 3 tabs.

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Radioisotope facilities were operated to support research, development and production of radioisotopes. Irradiation facilities were operated to offer irradiation service to the clients. Even though intensive periodical checks and some essential maintenance had been carried out the results of RI facility maintenance seemed to be not much satisfactory due mainly to the shortage of skilled manpower and maintenance expenses. High intensity {gamma} irradiator was normally operated 426 times for overall 3,440 hrs, and the low intensity {gamma} irradiator was operated 157 times for overall 11,092 hrs, respectively. (author)

International Nuclear Information System (INIS)

A nonlinear relationship between the time of accelerated aging of Lupine seeds and the indices of its survival as well as the single-strand DNA amount in cells from these seeds is established. The character of this relationship is essentially altered in chronically irradiated lupine seeds from the Chernobyl NPP exclusion zone and seems more complicated. The possible role of repair systems in these effects is discussed. The fact that chronic irradiation in low doses can modify the course of senescence in lupine seeds reflects its high biological efficiency comparing with acute irradiation.

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In view of the interest in the use of gamma irradiation to extend the storage life of pre-packaged foods a report is made on the effects of gamma radiation on the migration of Irganox 1076 and Irganox 1010, antioxidants present in food packaging plastics, into synthetic triglyceride fatty-food simulant HB307 and iso-octane. The extent of migration was assayed by h.p.l.c. techniques. Migration into HB307 and iso-octane decreased steadily as irradiation progressed suggesting that gamma irradiation of packaging materials helps to prevent the contamination of food by antioxidants in the packaging. (U.K.).

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... chemical radiation effects decomposition extraction columns gamma radiation

International Nuclear Information System (INIS)

Radiotherapeutic results of the Ewing sarcoma of the long tubular bones in 140 pediatric patients aged 3-16 are analyzed with the respect to different methods of irradiation. Three-field irradiation, the fields being located at 120 deg to one another with daily irradiation of all three fields at a focal dose of 2 Gy, was found superior in treatment of primary neoplasm. It is stressed that the disease termination mainly depends on the efficiency of primary neoplasm treatment, as the neoplasm reccurence generally is followed by metastases. Radiation load is calculated for maximal irradiation area of soft tissues in children.

International Nuclear Information System (INIS)

The effects of irradiation on microbiological controlling, nutrient and sensory qualities of packaged tofu (bean curd) stored at commercial condition. Results showed that D10 values of Listeria innocua and Samonella enteritidis inoculated in packaged tofu were 0.225 and 0.240kGy, respectively. Irradiation dose lower than 2.0kGy had no significant effects on content of crude protein and amino acid (p>0.05). ?-irradiation could decrease microbial in packaged tofu and 2.0kGy should be applied to ensure the hygienic quality of the products. (authors)

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Short communication. 1 ref., 4 figs.

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Structural changes of a Ni-P amorphous alloy under focused-ion-beam (FIB) irradiation have been examined using transmission electron microscopy. On the irradiated plane, the formation of crystallographically orientated nanosized crystals (NCs), with the particle size of approximately 10 nm, was observed. A series of electron diffraction analyses have revealed that NCs have a face-centered-cubic (fcc) structure and the following orientation relationships between the NCs and the FIB direction were found. These are, irradiated plane//(111)_f_c_c and FIB direction//_f_c_c.

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Japanese Mar 1999 p. 371-372 Japan Shi, Dequan Yamazaki, Takashi

Science.gov (United States)

We have compared the data retention of irradiated commercial NAND flash memories with that of

International Nuclear Information System (INIS)

2002 p. 9-10, 83-84 Russian Federation Glagolenko, Yu.V. Dzekun, EG

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

A computer-assisted rotation and stationary conformation radiotherapy system with overrunning multileaf collimators has been developed. This system can produce any shape of target volume, including a number of target areas outside the axis of the rotation, regardless of the location of the axis at 360"0 rotation irradiation. In addition, by changing the dose rate and deleting a partial region within a field, multiple stationary irradiation can produce more homogeneous target volumes - thus avoiding excessive irradiation to critical organs - than the rotation technique. (orig.).

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Japanese (Sep 1974). Japan Kudo, Susumu . Kansai Medical School,

International Nuclear Information System (INIS)

The paper reports the recovery of zinc and cadmium following 6.1 MeV alpha particle irradiation at 4.2 K as studied by means of electrical reistivity measurements. Specimens of 10 #mu#m thick have been used in order to obtain a homogeneous defect distribution over the whole thickness of the specimen. The pre-irradiation resistivity ratios were 700 and 750 for cadmium and zinc, respectively. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

The structural variations of amorphous metals, such as Pd/sub 80/Si/sub 20/, with irradiation of helium ion, neutron, and gamma ray have been mainly pursued by the method of X-ray diffraction and thermal analysis. It should be noticed that the amorphous metals show a radiation resistance, that is, no remarkable structural changes under helium ion, neutron, and gamma ray irradiation.

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Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

Energy Technology Data Exchange (ETDEWEB)

The study by impedance and photoelectrochemical measurements of passive films formed on an AISI 304 type stainless steel shows that important parameters of the electronic structure of these films are modified under ..cap alpha.. irradiation, namely: width of the space charge region, donors concentration and diffusion length for minority carriers. The consequences of ..cap alpha.. irradiation on localized corrosion processes are discussed.

International Nuclear Information System (INIS)

This report introduces present status on food irradiation at home and abroad in detail. It also introduces the scientific research and application in reducing diseases caused by food borne pathogens, quarantine control of import and export products, grain store and killing insects in traditional Chinese medicine. The report also analyzes the problems in developing food irradiation in China and gives some suggestions

Energy Technology Data Exchange (ETDEWEB)

Effects of gamma irradiation on hygienic quality and extraction yields in twenty-one kinds of Korean medicinal herbs were investigated. Gamma irradiation at 5-10 kGy inactivated contaminating microorganisms. The total extraction yield in fifteen kinds of the investigated medicinal herbs increased by 5-25% by a dose of 10 kGy. (author)

Energy Technology Data Exchange (ETDEWEB)

Heavy-ion irradiation technique has been developed for the evaluation of single-event effects on semiconductor devices. For the uniform irradiation of high energy heavy ions to device samples, we have designed and installed a magnetic beam-scanning system in a JAERI cyclotron beam course. It was found that scanned area was approximately 4 x 2 centimeters and that the deviation of ion fluence from the average value was less than 7%. (author)

International Nuclear Information System (INIS)

The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 deg. C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 ...

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Full text of publication follows: Li{sub 2}TiO{sub 3} is regarded as one of the most suitable candidates for the solid tritium breeder material of D-T fusion reactors. It is known that, in an operating fusion reactor, the radiation damage in Li{sub 2}TiO{sub 3} will be caused by fast neutrons, energetic tritons and helium ions generated in {sup 6}Li(n,{alpha}){sup 3}H reaction. The irradiation damage caused by such radiation may result in the microstructural changes, and the changes may affect the characteristics of Li{sub 2}TiO{sub 3} such as tritium release behavior. Thus the study of irradiation defects and microstructural changes caused by irradiation in Li{sub 2}TiO{sub 3} is essential to evaluate its irradiation performance. Simulation of the fusion reactor environment and hence the study of a synergistic effect of atomic displacement damage in Li{sub 2}TiO{sub 3} are approached by a simultaneous ...

International Nuclear Information System (INIS)

This paper discusses the economics of legumes irradiation such as Chickpea,Lupin,Kidny Bean and broad and the effect of various parameters on unit processing costs. It provides a model for calculating specific unit processing costs by correlating known capital costs with annual operation cost an annual throughputs. We analysed the cost-benefit of the proposed grain irradiation facility. We took into account the cost of the capital investment, operation and other additional parameters and then estimated the unit processing cost. The investment criteria utilized for commercial evaluation were internal rate of return (I.I.R), pay back period (P.B.P), and average rate of return (A.R.R). The irradiation cost and the additional income are also discussed. The results of this analysis showed that the installation of an irradiation unit for legumes processing in Egypt would be economically feasible.

International Nuclear Information System (INIS)

The influence of electron-beam irradiation on mechanical properties of commercial multilayer flexible packaging materials based on coextruded and laminated polypropylene (PP), low-density polyethylene (LDPE), ethylene vinyl alcohol copolymer (EVOH) and poly(ethylene terephthalate) (PET), irradiated with doses up to 120 kGy, was studied. The tensile strength and elongation at break of the irradiated PET/PP film increase, while the penetration and sealing resistance decreased. In addition, the irradiated PET/LDPE/EVOH/LDPE film presented increase in the tensile strength on some radiation doses and decrease of the penetration and sealing resistance, except for sealing resistance at radiation dose of 15 kGy that resulted in a slight increase of ca 4%.

Energy Technology Data Exchange (ETDEWEB)

Medicinal plants i.e. dried seeds of myristica argentea, myristica fragrans, coriandrum sativum and foeniculum vulgare were stored for 0 and 6 months, with and without gamma irradiation at 5 kGy. No detectable changes were seen in infrared and UV spectra, GLC chromatograms and refraction indices of steam distilled, essential oils from the irradiated medicinal plants. The same results were also obtained from irradiated samples stored for 6 months at ambient conditions. Storage for 6 months caused significant changes in the gas liquid chromatograms and UV spectra of all samples compared to non-stored samples. The moisture content of all samples packed in polyethylene bags seems to be constant after 6 months of storage. No measurable changes were found in the amount of essential oil content caused by irradiation.

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A total of 86 experimental fuel pins with various fuel, liner, and cladding candidate materials have been irradiated in the Experimental Breeder Reactor-II (EBR-II) and the Fast Flux Test Facility (FFTF) reactor as part of the SP-100 fuel pin irradiation testing program. Postirradiation examination results from these fuel pin are key in establishing performance correlations and demonstrating the lifetime and safety of the reactor fuel system. This paper provides a brief description of the in-reactor fuel pin tests and presents the most recent irradiation data on the performance of wrought rhenium (Re) liner material and high density UN fuel at goal burnup of 6 atom percent (at. %). It also provides an overview of the significant variety of other fuel/liner/cladding combinations which were irradiated as part of this program and which may be of interest to more advanced efforts.

International Nuclear Information System (INIS)

The invention refers a procedure of radiation dose control in irradiated tissues during electron-beam therapy. It aims at meeting the planned radiation dose for diseased tissues and taking care of the healthy ones. Therefore, the dose distribution required is determined before irradiation in consideration of such factors as energy-dependence of detector sensitivity, self-absorption within the tissue, and relative biological effectiveness. Furthermore, the expected intensity distribution of secondary quantum radiation excited in the irradiated tissue is calculated. A radiation detector for local resolution is used for registration. During irradiation the calculated intensity distribution is compared with the measured one. The invention is applicable in radiation therapy with monoenergetic electron beams.

International Nuclear Information System (INIS)

Joint FAO/IAEA/WHO Expert Committee approved the use of radiation treatment of foods. Nowadays food packaging are mostly made of plastics, natural or synthetic, therefore effect of irradiation on these materials is crucial for packing engineering for food irradiation technology. By selecting the right polymer materials for food packaging it can be ensured that the critical elements of material and product performance are not compromised. When packaging materials are in contact with food at the time of irradiation that regulatory approvals sometimes apply. The review of the R-and-D and technical papers regarding material selection, testing and approval is presented in the report. The most information come from the USA where this subject is well elaborated, the International Atomic Energy Agency (IAEA) reports are reviewed as well. The report can be useful for scientists and food irradiation plants ...

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Materials for the construction of cold neutron sources must satisfy a range of demands. The cryogenic temperature and irradiation create a severe environment. Candidate materials are identified and existing cold sources are briefly surveyed to determine which materials may be used. Aluminum- and magnesium-based alloys are the preferred materials. Existing data for the effects of cryogenic temperature and near-ambient irradiation on the mechanical properties of these alloys are briefly reviewed, and the very limited information on the effects of cryogenic irradiation are outlined. Generating mechanical property data under cold source operating conditions is a daunting prospect. It is clear that the cold source material will be degraded by neutron irradiation, and so the cold source must be designed as a brittle vessel. The continued effective operation of many different cold sources at a number of ...

International Nuclear Information System (INIS)

Nano indentation analysis and transmission electron microscopy observation were performed to investigate a microstructural evolution and its influence on the hardening behavior in Fe-Cr alloys after an irradiation with 8 MeV Fe4+ ions at room temperature. Nano indentation analysis shows that an irradiation induced hardening is generated more considerably in the Fe-15Cr alloy than in the Fe-5Cr alloy by the ion irradiation. TEM observation reveals a significant population of the a0 dislocation loops in the Fe-15Cr alloy and an agglomeration of the 1/2a0 dislocation loops in the Fe-5Cr alloy. The results indicate that the a0 dislocation loops will act as stronger obstacles to a dislocation motion than 1/2a0 dislocation loops.

International Nuclear Information System (INIS)

Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by #gamma#-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H_5_0 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from "4"0K contained in the samples. (author).

Energy Technology Data Exchange (ETDEWEB)

In FY1994, JMTR was in operation during 4 operation cycles with low enriched Uranium(LEU,20%) fuel for irradiation study of nuclear fuels and materials and for radioisotope production. Irradiation studies were carried out using capsules, Oarai Gas Loop-1(OGL-1), Oarai Shroud Facility(OSF-1) and hydraulic rabbits irradiation facilities in support of LWR, FBR, HTTR and thermonuclear reactor. Irradiation studies on blanket materials were intensively carried out. Power ramping tests were carried out and the future program is under consideration. For R and D works, neutron spectrum evaluation technology, re-instrumentation technique for irradiation fuel rod, remote controlled SEM apparatus and examination technique with miniaturized specimens were successfully developed. (author).

International Nuclear Information System (INIS)

The effects of gamma irradiation at 0.2#approx#0.4 Mrad and condition for processing of buckwheat noodles on sensory quality and physical properties were investigated. The results were as follows: (1) Sensory evaluation of buckwheat noodles, prepared with the 70 % ratio of buckwheat flour, was decreased according to an increase of irradiation dose of buckwheat flour. Hardness and adhesiveness of buckwheat noodles caused by irradiation should be given large effect to the texture. Elasticity of buckwheat noodles was linearly decreased with increasing of irradiation dose of buckwheat flour, and elasticity of buckwheat noodles was decreased about 15 % by an increase of irradiation dose at 0.3 Mrad. (2) Maximum torque in Farinograph test was linearly decreased with increasing of irradiation dose of buckwheat flour, and maximum torque was decreased about 3 % by ...

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In order to protect food from pathogenic microorganisms as well as to increase its shelf life while keeping sensorial properties (e.g. odor and taste), once the latter are one of the main properties required by spice buyers, it is necessary to analyze volatile formation from irradiation of medicinal and food herbs. The aim of the present study was to analyze volatile formation from Co irradiation of Laurus Cinnamomum, Piper Nigrum, Origanum Vulgare and Myristica Fragans. Possible changes on the odor of these herbs are evaluated by characterizing different radiation doses and effects on sensorial properties in order to allow better application of irradiation technology. l he samples have been irradiated in plastic packages by making use of a {sup 60}Co Gamma irradiator. Irradiation doses of 0, 5, 10, 15, 20 and 25kGy have been tested. For the analysis of the ...

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The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18{sup 0}C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4{sup 0}C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also observed in some cross sections. Irradiation ...

International Nuclear Information System (INIS)

The fading of irradiated and natural blue-colored pearls was investigated in this experiment. Thirty natural blue-colored pearls and sixty irradiated blue-colored pearls were used. Some of them were placed at a light position of RT. Another pearls were placed at a dark position of 50"0C. The irradiated pearls placed at a light position of RT didn't show remarkable fading in their color in 294 days. But the natural blue-colored pearls showed a little recovery from 4% to 8% in reflection factors in 223 days at RT. The irradiated pearls placed at a dark position of 50"0C showed the recovery from 9% to 14% in 264 days independently of irradiation times. The natural blue-colored pearls also showed the bleaching from 5% to 10% in reflection factor in 86 days at 50"0C. Both irradiated and natural blue-colored pearls hardly showed their remarkable changes in their ...

Energy Technology Data Exchange (ETDEWEB)

The fading of irradiated and natural blue-colored pearls was investigated in this experiment. Thirty natural blue-colored pearls and sixty irradiated blue-colored pearls were used. Some of them were placed at a light position of RT. Another pearls were placed at a dark position of 50/sup 0/C. The irradiated pearls placed at a light position of RT didn't show remarkable fading in their color in 294 days. But the natural blue-colored pearls showed a little recovery from 4% to 8% in reflection factors in 223 days at RT. The irradiated pearls placed at a dark position of 50/sup 0/C showed the recovery from 9% to 14% in 264 days independently of irradiation times. The natural blue-colored pearls also showed the bleaching from 5% to 10% in reflection factor in 86 days at 50/sup 0/C. Both irradiated and natural blue-colored pearls hardly showed their ...

Energy Technology Data Exchange (ETDEWEB)

The irradiation behavior of Li{sub 2}TiO{sub 3} under a fusion reactor environment was simulated by simultaneous irradiation of Li{sub 2}TiO{sub 3} by the triple ion beams and the respective single ion beams of O{sup 2+}, He{sup +} and H{sup +}. The microstructural changes in Li{sub 2}TiO{sub 3} caused by the irradiation were measured by FT-IR photoacoustic spectroscopy. The results suggest that the amount of TiO{sub 2} formed is proportional to the dpa and that the method of irradiation does not affect the dependence of formation of TiO{sub 2}. On the other hand, the amount of defects and/or radiolytic products generated by irradiation, which is considered to trap hydrogen near the surface, is found to be affected by the method of irradiation. Such phenomena are believed to affect the tritium release behavior from Li{sub 2}TiO{sub 3}, and durability of Li{sub ...

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Tensile specimens of the normalized and tempered fully martensitic steel DIN 1.4914 were helium implanted up to 340 appm within the temperature range 300-720/sup 0/C using a 104 MeV alpha particle beam. The high He/damage ratio of 1850 appm He/dpa allowed to determine the effect of helium on material properties. After irradiation tensile strength and ductility were investigated mainly at test temperatures equal to the irradiation temperatures. While short time irradiations with helium contents up to 100 appm have shown no visible effect on the tensile behaviour at all temperatures investigated, long time irradiations reduced the material strength at irradiation temperatures above about 440/sup 0/C. This irradiation induced softening obscured the predicted minor hardening effect of the observed He-bubbles completely and increases with ...

British Library Electronic Table of Contents (United Kingdom)

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...

International Nuclear Information System (INIS)

The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae - a wild type strain and a mutant deficient in excision repair - were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation in Saccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains. (orig.).

CERN Document Server

We present experimental studies on the photoionization and photodissociation processes (photodestruction) of gaseous amino acids and nucleobases in interstellar and interplanetary radiation conditions analogs. The measurements have been undertaken at the Brazilian Synchrotron Light Laboratory (LNLS), employing vacuum ultraviolet (VUV) and soft X-ray photons. The experimental set up basically consists of a time-of-flight mass spectrometer kept under high vacuum conditions. Mass spectra were obtained using photoelectron photoion coincidence technique. We have shown that the amino acids are effectively more destroyed (up to 70-80%) by the stellar radiation than the nucleobases, mainly in the VUV. Since polycyclic aromatic hydrocarbons have the same survival capability and seem to be ubiquitous in the ISM, it is not unreasonable to predict that nucleobases could survive in the interstellar medium and/or in comets, even as a stable cation.

British Library Electronic Table of Contents (United Kingdom)

The light-emitting properties of cubic silicon carbide films grown by vacuum vapor phase epitaxy on Si(100) and Si(111) substrates under conditions of decreased growth temperatures (T gr ? 900?700?C) have been discussed. Structural investigations have revealed a nanocrystalline structure and, simultaneously, a homogeneity of the phase composition of the grown 3C-SiC films. Photoluminescence spectra of these structures under excitation of the electronic subsystem by a helium-cadmium laser (?excit = 325 nm) are characterized by a rather intense luminescence band with the maximum shifted toward the ultraviolet (?3 eV) region of the spectral range. It has been found that the integral curve of photoluminescence at low temperatures of measurements is split into a set of Lorentzian components. Th...

Science.gov (United States)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 ..mu.., allows individual MCP channels to be distinguished. (AIP)

British Library Electronic Table of Contents (United Kingdom)

Zooplankton tolerant to ultraviolet radiation (UVR) could be indirectly affected by UVR through interactions with UV-sensitive species in the same ecosystem. In Lake Giles, Pennsylvania, USA, the calanoid copepod Leptodiaptomus minutus is more UVR tolerant than the cohabiting species Daphnia catawba and Cyclops scutifer. We asked whether L. minutus is affected by UV-induced mortality of a food competitor (D. catawba) or a predator of its nauplii (C. scutifer). We conducted two in situ enclosure experiments with six treatments: L. minutus alone, L . minutus + Daphnia and L. minutus + Cyclops in the presence and absence of UVR. There were few differences in survival among treatments in Experiment 1, which had enhanced food and a cumulative UVR (320 nm) dose of 9.3 kJ m-2. In Experiment 2, wh...

International Nuclear Information System (INIS)

Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.

Energy Technology Data Exchange (ETDEWEB)

The kinetics of alkaline hydrolysis of methylparathion was studied at different temperatures (0-50 Centigrade) in the p H range of 8-12 by ultraviolet-visible absorption spectroscopy. Optimum p H and wavelength conditions were defined to carry out the simultaneous determination of methylparathion and one of its hydrolysis product, paranitrophenol, in buffered aqueous medium. Based on the experimental data and the mathematical equation of the kinetics, a rate constant (k) of first-order and an activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author) activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author)

International Nuclear Information System (INIS)

The intrinsic fluorescence of clear amniotic fluid from third-trimester pregnancy is reported. The fluorescence intensity peaked at 405 nm when excited by ultraviolet light in the range of 310 to 360 nm. All of the 33 samples tested fluoresced, and their emission spectrum had the same shape, varying only in magnitude. Changing sample temperature (20 to 50 C) and sample pH (7.2 to 7.7) had little effect on the emission spectrum. The same fluorescence, with higher intensity, was observed when some newborn urine was tested. The fluorescence of amniotic fluid may provide a new tool to determine fetal age, fetal organ maturation, and fetal distress. (author).

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

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Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.

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A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

International Nuclear Information System (INIS)

Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths (#lambda# = 0.3...20 #mu#m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

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Composting of sawdust and paper mill sludge, using a 'Kneer' process reactor, was studied in an attempt to elaborate upon organic matter transformation during the process and to define parameters to measure the compost maturity level. Temperature, electron paramagnetic resonance data, ash and C, H, N and S contents, and a spectroscopic method using ultraviolet-visible (UV-VIS) for alkaline (pH = 8.5) and solid samples was used to study the maturity of the compost samples. These parameters were measured in 6 humic acids extracted from the compost samples during 29 days. The results of this work show that the 'Kneer' process is efficient in transforming ligno-celulitic residues in a short time (29 days), into an organic fertilizer material with application perspectives (author)

Energy Technology Data Exchange (ETDEWEB)

Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was performed using transmission electron microscopy and energy dispersive spectroscopy, with NiTi, Ni4Ti3, Ni3Ti, and Ni2Ti4Ox phases identified within the microstructure of the alloy. Density functional theory was applied to predict the electronic structure of the NixTiy phases, including the band structure and site projected density of states. Ultraviolet photoemission spectroscopy was used to verify the density of states results from the density functional theory calculations, with good agreement observed between experiment and theory.

International Nuclear Information System (INIS)

Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures.

British Library Electronic Table of Contents (United Kingdom)

An electrochemical biosensor for determination of hydrogen peroxide (H2O2) was fabricated, based on the electrostatic immobilization of horseradish peroxidase (HRP) with one-dimensional gold nanowires (Au NWs) and TiO2 nanoparticles (nano-TiO2) on a gold electrode. The nano-TiO2 can give a biocompatible microenvironment and compact film, and the Au NWs can provide fast electron transferring rate and greatly add the amount of HRP molecules immobilized on the electrode surface. Au NWs were characterized by ultraviolet?visible spectra and transmission electron microscope. The electrode modification process was probed by cyclic voltammetry and electrochemical impedance spectroscopy. Chronoamperometry was used to study the electrochemical performance of the resulting biosensor. Under optimal co...

British Library Electronic Table of Contents (United Kingdom)

A novel liquid phase alkylation of aniline with methanol over Zn/Cu salts modified kaolin assisted with a pair of porous carbon electrode in slurry-bed reactor under constant current intensity, room temperature and atmospheric pressure was reported. The Zn/Cu salts modified kaolin catalysts were synthesized and characterized by infrared spectrometer (IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the transition metals were completely supported on kaolins structure and formed a pored one. The effect parameters, such as initial pH, electrolysis time, metal ratio with kaolin and salts composition in this electrochemical catalytic system, were studied. The procedure was inspected by ultraviolet-visible spectrum (UV-vis), and the product distributi...

International Nuclear Information System (INIS)

Thermal diffusivity was measured with a laser flash method up to 2000 K for UO_2 pellets irradiated in a commercial reactor. Measurements were done on micro samples of disks (2 mm diameter) or regular prisms (1.5 or 2 mm square cross sections). Thermal diffusivity degraded on extending burnup in agreement with reported values for UO_2 irradiated in test reactors, and it showed hysteresis during the laser flash experiments. Thermal diffusivity began to recover above 750 K and almost completely recovered above 1400 K, which corresponded with the reported radiation damage recovery. The obtained data were in agreement with predictions applying the thermal conductivity expression for irradiated UO_2 proposed by Amaya and Hirai. The sample experiencing power ramp showed higher thermal diffusivity than that of the base irradiated sample and had no obvious hysteresis. This suggested that the radiation damage ...

International Nuclear Information System (INIS)

Active oxygens produced by low-dose irradiation can induce the synthesis of proteins involved in the active oxygen reduction path and can activate the chemical self-defense mechanisms in vivo, which can alleviate the injuries caused by active oxygens themselves. The following findings suggests that it is not only by low-dose irradiation that can induce the responses described above but also by any physical and/or chemical stresses which can produce small amount of active oxygens in vivo. 1. X-irradiation with 0.5 Gy and/or water immersion and restraint induced heat shock protein (HSP)70 in rat stomach cells. HSP70 was also induced in adrenal cells by paraquat administration. 2. The SOD activity in pancreas of rat significantly increased by #gamma#-irradiation with 0.5 Gy. 0.5 Gy irradiation preceeding the alloxan administration significantly suppressed the increase in pancreatic ...

International Nuclear Information System (INIS)

The present work is to study effects of neutron irradiation on the structure of amorphous Pb_8_0 Si_2_0 and Pd_7_7_._5 Cu_6 Si_1_6_._5 alloys by using X-ray diffraction techniques. differential scanning calorimertry (DSC) and internal friction measurements. The irradiation will produce obvious changes in the pair correlation function g(r) and radial distribution function RDF (r). The increase of crystallization temperature (Tx) and enthalpy of two specimens were found by DSC measurements after irradiation. The results of internal friction measurement show that the internal friction of the irradiated Pd_8_0Si_2_0 alloy is higher than that of the unirradiated in the temperature range of Tirradiation are discussed in terms of the concepts of density fluctuation defects (p) and shear stress fluctuation defects (#iota#).

Energy Technology Data Exchange (ETDEWEB)

In the Institute for Atomic Energy, Rikkyo University, just after the TRIGA-2 research reactor of 100 kW has attained the criticality, the cylindrical box for neutron radiography (NR) irradiation was made in the attached pool, and the research on NR was started in 1961. Thereafter in 1985, the vertical irradiation pipe was installed in the reactor tank, and the experiment for collecting the basic data was begun. In 1986, based on the obtained data, the NR irradiation facility on full scale was installed in No. 2 tangential horizontal experimental hole. As the main NR irradiation facilities, the vertical neutron irradiation pipe, the use of which is stopped now, the NR facility using the horizontal experimental hole (RUR/N2), the irradiation facility and ancillary facilities such as beam shutter, beam catcher and hoist are described. As the main equipments for ...

International Nuclear Information System (INIS)

Researches on oil palm empty fruit bunch (EFB) fibers and thermoplastic composites have been carried out by many workers in the last decade. The main focus was to enhance the properties of the resultant composites in view of the incompatibility of the two components. Thus, efforts have been made to enhance their properties by using coupling agents, treating the fibers and modifying the matrices. In this study, the effects of electron beam (EB) irradiation and some reactive additives (RAs) on the mechanical properties of EFB-PP (polypropylene) composites were evaluated. Different modes of irradiation were investigated. Mono, di and tri functional of monomers of RAs were used. irradiating PP alone, compared to irradiating the EFB fibers or irradiating both components, gave optimum properties for EFB-PP composites. Further, improvements of the properties of the composites were achieved ...

Energy Technology Data Exchange (ETDEWEB)

The research and development for the first year of the project are performed through specialization of researchers, information from aborad and international cooperation, securement of advanced nuclear technology, development and installation of test equipment, application of external man-power, establishment of advanced test techniques, and certified test method. 1. Absolute efficiency measurement examination technology development of gamma scanning system 2. Sample preparation technology development of SEM and EPMA for micro-structural observation and chemical composition analysis 3. Irradiated high burn-up nuclear fuel transportation and test for PWR 4. Development of hot cell examination techniques and equipment 5. Acquirement of KOLAS system. In addition to the project, the following activities are carried out as follows; - PIE of Hanaro fuel(KH99H-001) - PIE of U-Mo advanced nuclear fuel irradiated at Hanaro - PIE of Hi-MET advanced ...

International Nuclear Information System (INIS)

Radioactive particles as well as x irradiation from an external source has been used in the treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. In order to clarify effects of ionizing irradiation on synovial cells, radioactive gold ("1"9"8Au) and yttrium ("9"0Y) were added to fibroblast cultures derived from human synovial membranes. Other cultures were irradiated by a Picker x-ray machine. Fibroblast growth and hyaluronic acid production were measured. Radioactive gold and yttrium particles induced a significant increase of hyaluronic acid synthesis rate (pg/cell/day) and inhibited fibroblast growth. Fibroblasts continued to overproduce hyaluronic acid and to show growth inhibition 3 weeks after irradiation with radioactive gold. Hydrocortisone inhibited hyaluronic acid overproduction induced by radioactive gold. Overproduction of hyaluronic acid induced by the x-ray machine ...

Energy Technology Data Exchange (ETDEWEB)

The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop in-reactor assembly (CLIRA), and other special fuel ...

Energy Technology Data Exchange (ETDEWEB)

This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on ovary. Immature mice (ICR, 3 week-old) were irradiated at a dose of LD{sub 80(30)} at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. To analyze the morphological changes, histological staining with hematoxylin-eosin, immuno- histochemical preparation using in situ 3'-end labeling was performed. DNA fragmentation analysis and flowcytometric evaluation of DNA extracted from whole ovary were performed. As a result of DNA fragmentation analysis, DNA fragments with 185, 370, and 555 base pairs were clearly shown at 6 hours post irradiation. The percentage of A{sub 0} cell cycle was significantly increased in the irradiated group than control. In situ 3'-end labeled follicles were increased at 6 hours post irradiation. ...

International Nuclear Information System (INIS)

Structural variations in 39-MeV alpha-particle irradiated (Tsub(irr) = 60 deg C) polycrystalline molybdenum during post-irradiation annealing were studied by X-ray and TEM methods. Despite the high density of irradiation induced defects in the structure of the specimen X-ray measurements showed zero relative lattice parameter change after an irradiation dose of 1.1 x 10"-_2 dpa. However, during the annealing #delta#a/a was changed in the positive range, exhibiting two peaks - at 100 and 300 deg C - whereas the damage structure detected by TEM indicated no changes. Analysis of the results leads to the conclusion that in the range 100 to 250 deg C migration of isolated vacancies and their annihilation at interstitial clusters as well as possible formation of new vacancy clusters occur. The second peak on the #delta#a/a temperature dependence curve is related to the transformation (probably, thermal ...

International Nuclear Information System (INIS)

The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and "6"0Co #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 "oC 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 ...

Energy Technology Data Exchange (ETDEWEB)

A new small size gamma irradiator is being set up at Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil, with a revolutionary design. The developed technology for this facility consists of continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m{sup 2} of floor area, the irradiator design is product overlap sources and the maximum capacity of Cobalt-60 wet sources is 37 PBq (1 MCi). The irradiator is being installed in a Governmental Institution and it will be used as a demonstration facility for manufacturers, who need an economic and logistic in-house irradiation system alternative. Also, it will be useful for supporting the local scientific ...

International Nuclear Information System (INIS)

A study was made into microstructure and hardening in austenitic stainless steel 0Kh18N10T irradiated with neon ions (230 MeV) and neutrons (E_n > 0.1 MeV). The experiments were accomplished using an external beam of U-400 cyclotron (Dubna) and EWA reactor (Poland). The dependences of tensile properties, hardening index, microstructure, dislocation density on damaging dose were determined. An attempt is made to reveal the correlation between an yield strength increment and defect cluster accumulation. The interpretation of variations of mechanical properties and microstructure under irradiation is given.

International Nuclear Information System (INIS)

Thermal analysis testing revealed slight weight changes, which were a function of gamma irradiation, in a highly reduced Defense Waste Processing Facility (DWPF) simulated waste glass. Transmission electron microscopy (TEM) was performed on this glass to determine if the weight change corresponded to microstructural variations. TEM analyses showed that no microstructural changes were attributable to gamma irradiation. Exposure of the samples to the electron beam in the TEM did cause changes in the glass microstructures in some cases. These changes were likely due to localized heating of the glass due to interactions with the transmitted electrons.

International Nuclear Information System (INIS)

The behavior of the superconducting transition temperature T/sub c/ of single-crystal and polycrystalline V_3Si was investigated as a function of low-fluence neutron irradiation. It is found that the initial degradation of T/sub c/ is sample-dependent, some specimens showing no degradation in T/sub c/ up to a fluence of 2 x 10"1"8 n/cm"2. This and many other earlier observations on low-fluence behavior are explained in terms of a recently proposed model of radiation damage in A-15 compounds.

Energy Technology Data Exchange (ETDEWEB)

The short range of low-energy electrons has made them suitable for the treatment of skin lesions, especially when extensive areas must be irradiated with special considerations to save the normal underlying tissue. This report covers some salient features of total body electron irradiation: the construction of the large fields required, x-ray contamination levels, and multiple-field techniques. While the investigation is essentially experimental, we also indicate the results of calculations. We conclude most generally that treatment planning with whole skin irradiations can be as precise as with smaller fields.