International Nuclear Information System (INIS)

Polytetrafluoroethylene was obtained by radiation induced polymerization of tetrafluoroethylene in acetone at 195 K. An average diameter of the products was very small compared with commercial one; it was about 0.3 micro-meters. The yield was reached to 100% with a dose of 4 kGy. The crystallinity of the products is decreasing with increasing dose. The products become amorphous, for higher irradiation doses. It was found that PTFE obtained by irradiation of TFE in acetone at 195 K has branching structure. This was demonstrated by means of "1"9F MAS NMR. (Author)

International Nuclear Information System (INIS)

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and ...

International Nuclear Information System (INIS)

A new kind of e-beam bunching enabling the production of coherent spontaneous emission (CSE) is proposed and considered. It is shown that an e-beam in passing through an undulator will induce CSE along with incoherent spontaneous radiation on the same wavelength if the e-beam transverse velocity is modulated with a spatial period twice as long as the radiation wavelength. Such angular modulated beams can be regarded as alternatives to conventionally density modulated beams for CSE production. Requirements for e-beams are similar in both cases.

Science.gov (United States)

duced and spontaneous radiation. The amount of polarization is ... of the induced and spontaneous radiation patterns. Therefore ...

Energy Technology Data Exchange (ETDEWEB)

The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

International Nuclear Information System (INIS)

One of the greatest opportunities for using of biomass as a precursor in the production of polymeric materials is the lignocellulose composites that can combine high performance with low costs. This work is a initial study on the production of a lignocellulose reinforced polyethylene composite. A compatibilization made by a induced gamma radiation grafting reaction was used to increase the adhesion between the matrix and the reinforced or filled fibers. The lignocellulose materials were exposed to gamma radiation in order to promote a molecular degradation and increase its reactivity. The polymer, the lignocellulose material and the compatibilization were processed by extrusion and the composite produced by this process were characterized by mechanical tests. (author)

CERN Document Server

Differences in synchrotron radiation induced gas desorption from stainless steel and aluminium alloy

International Nuclear Information System (INIS)

Ionizing radiation, mainly in the form of #gamma#-rays from the radioisotope cobalt 60, is being used increasingly for the inactivation of contaminants in cosmetic and toiletry preparations. The treatment is applied to the product in its final pack, and therefore, it is important to recognize that the properties of the packaging materials could be affected, particularly if high radiation doses are used. The stability of a wide range of materials is discussed. The nature and extent of chemical and physical changes in plastics very much depends on the presence of antioxidants and other additives, and on the environmental conditions during irradiation. Some useful information is available from research into the use of radiation for the preservation of food - many films and laminates have been cleared for use in the United States. The low radiation doses used for the control of ...

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.

International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Most plans for the disposition of surplus nuclear materials involve storage in sealed containers where the evolution of gases from reactions of adsorbed water could present both pressure and flammability hazards[l] . Despite efforts such as calcining the material to minimize the water content prior to packaging, both residual moisture and readsorbed water may be present in the final containers . Given the anticipated temperature excursions during transportation and storage, this water may thermally desorb, increasing the pressure, and/or thermally dissociate to produce H2 gas, increasing flammability hazards . In addition, the radiation from the nuclear material may induce radiolysis of the water with the likely products being water vapor, H2, 02 and H2O2. In order to better understand the relative importance of the thermal- and radiationinduced chemistry, we have studied the interactions of water on single crystals of ...

International Nuclear Information System (INIS)

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at #gamma##gamma# colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of #mu#"+#mu#"-, #tau#"+#tau#"-, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan#beta#-bar 5 (30) and large (small) charged Higgs-boson masses.

Energy Technology Data Exchange (ETDEWEB)

Population residing in the northern part of the Chelyabinsk oblast and the south eastern part of the Sverdlovsk oblast of Russia affected to accidental exposure since 1957. The territory (East Ural Radioactive Trace - EURT) was contaminated after explosion of container with highly radioactive wastes at the Mayak Production Association. Studies of health effects of exposure in the southern, head part of EURT are conducted in the Ural Research and Practical Center of Radiation Medicine (U.R.P.R.M.). In the 1990's U.R.P.C.R.M. formed a cohort of EURT within Chelyabinsk oblast (14,500 cases and 19,400 external controls). The cohort was followed in 1957-1987 and the results of the study are discussed by Crestinina et al. First results of study on exposure late health effects among rural population in the northern part of the EURT are presented in this paper. Firstly, or the period 1958-2000 a statistically significant increase in cancer ...

Science.gov (United States)

The induced radioactivity in the construction materials of a Cockcroft-- Walton type neutron generator was measured. Major activation products (/sup 24/ Na, /sup 28/Al, /sup 56/Mn, /sup 64/Cu, /sup 65/Ni, /sup 69m/Zn, /sup 88/Rb /sup 91/Sr /sup 101/Mo, /sup 187/W/ and resulting doses are tabulated. Results show that the highest gamma activities would be observed in the fluorescent bulbs, copper pipe, aluminum lattice rod, and the aluminum pipe clamp. Thermoluminescent dosimeter readings yield the highest doses for the copper pipe tee, copper pipe, and aluminum lattice rod. Results of measuremerts of the neutron and gamma dose profiles of the facility are shown. However the indication is clearly that the tritium target, compared to other components, is the major source of radiation both during and after shutdown. (UK)

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring ...

International Nuclear Information System (INIS)

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease ...

Medline Plus

... Animal & Veterinary Cosmetics Radiation-Emitting Products Tobacco Products Drugs Home > Drugs > Resources for You > Information for Consumers (Drugs) Section ...

International Nuclear Information System (INIS)

Conditions for radiation induced grafting with butyl acrylate dispersed in water emulsion onto chrome-tanned pig skins have been worked out for #gamma#-rays and electron beam irradiations. The highest yield of grafting was observed at monomer concentration approximately 25% (w/w), dose equal to 25 kGy and dose rate not exceeding 10 MGy/h. At these conditions the yield of grafting attained a value approximately 25% and content of homopolymer in the leather amounted to 6%. The efficiency of monomer to polymer conversion decreases when the concentration of monomer in emulsion and dose rate increases. Yield of homopolymer is independent of the dose rate. An explanation of the observed relations has been proposed. The physical and used properties of grafted leathers were tested. Radiation processed leathers were found superior to samples finished by traditional methods. One has to point to better tolerance against chemical ...

Energy Technology Data Exchange (ETDEWEB)

In scattering of channeled particles by point defects and in emission of gamma rays in the spontaneous-radiation spectral region conditions are attained where the momentum transferred to the defect is taken up by the crystal as a whole. This leads to coherent and interference effects in the radiation from the crystal defects. When the longitudinal momentum transferred is zero, an induced radiation effect appears in the transitions between the states of transverse motion.

International Nuclear Information System (INIS)

... of Sciences (Poland) [5.48 Megabytes] NUCLEAR PHYSICS AND RADIATION

International Nuclear Information System (INIS)

Full text: DNA rearrangement events leading to chromosomal aberrations are central to ionizing radiation-induced cell death. Although DNA double-strand breaks are probably the lesion that initiates formation of chromosomal aberrations, little is understood about the molecular mechanisms that generate and modulate DNA rearrangement. Examination of the sequences that flank sites of DNA rearrangement may provide information regarding the processes and enzymes involved in rearrangement events. Accordingly, we developed a method using inverse PCR that allows the detection and sequencing of putative radiation-induced DNA rearrangements in defined regions of the human genome. The method can detect single copies of a rearrangement event that has occurred in a particular region of the genome and, therefore, DNA rearrangement detection does not require survival and continued multiplication of the affected cell. Ionizing ...

Energy Technology Data Exchange (ETDEWEB)

This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by ...

Energy Technology Data Exchange (ETDEWEB)

Color formation in aqueous solutions of the ditetrazolium salt blue tetrazolium (BT{sup 2+}) in the absence or presence of oxygen is a complex radiation chemical reaction. The final stable product is the poorly soluble diformazan violet to blue pigment having a broad spectral absorption band ({lambda}{sub max}=552 nm). The reaction of BT{sup 2+} with the hydrated electron proceeds by rapid reduction of BT{sup 2+} followed by protonation at the nitrogen closest to the unsubstituted phenyl group, via the two intermediate tetrazolinyl radicals shared by the ditetrazole ring nitrogens. The effect of solution pH, N{sub 2}O saturation, and the presence of the reducing agent dextrose are examined. The system serves as a radiochromic sensor and a dosimeter of ionizing radiations. Solutions of 5 mmol l{sup -1} BT{sup 2+} at pH 7.3 serve as dosimeters over an absorbed-dose range of approximately 0.2-6 kGy (dearated, with a range of ...

International Nuclear Information System (INIS)

Cell death after irradiation occurs by apoptosis in certain cell populations in tissues. The phenomenon also occurs after high linear energy transfer (LET) irradiation, and the relative biological effectiveness (RBE) is 3 to 4 (with respect to low-LET radiation and apoptosis in intestinal crypts) for neutrons with energies of 14 MeV and up to 600 MeV. It is thought that p53 plays a role in the phenomenon, as radiation-induced apoptosis is not observed in p53-null animals. (orig.).

International Nuclear Information System (INIS)

... compilation fission products j codes mixed oxide fuels neutron reactions

Science.gov (United States)

... of Dist SpeA tI/ __LLL5' Page 5. 3 the coherent effects on the spontaneous radiation, we calculate the pump- field-induced ...

UK PubMed Central (United Kingdom)

PurposeRadiation-induced heart disease (RIHD) is a severe side effect of thoracic radiotherapy. This study examined the effects of PTX and α-tocopherol on...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Natural sunlight induces a genotoxic response in cultured CHO cells pre-treated with shale oil retort process water. Near ultraviolet light (NUV) component of the solar spectrum is the apparent radiation responsible for photoactivation. Cultured human skin fibroblasts are acutely sensitive to the genotoxic effects of photoactivated process water. The mutagenic potential of photoactivated process water in human cells is the same as that witnessed for an equivalent killing dose of the potent skin carcinogen FUV. DNA repair processes are involved in modulating genotoxic effects of this photo-induced process. The exact magnitude of the potential health-related and environmental risks resulting from photoactivation of retort process waters and other oil shale by-products is unassessed at this time. Our demonstration that a significant rate of mutation occurs in cultured human cells exposed to high dilutions ...

International Nuclear Information System (INIS)

The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H_2O_2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H_2O_2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H_2O_2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect ...

International Nuclear Information System (INIS)

A computerised glow curve deconvolution (CGCD) analysis was applied to the main dosimetric peak of #alpha#-Al_2O_3:C in order to study the effects of light on the glow curve shape. It was shown that both the light-induced signal and the light-induced fading effects tend to shift the main dosimetric peak to higher temperatures and at the same time change its shape. Furthermore it was confirmed that the magnitude of the light-induced signal depends on radiation history and, by increasing the duration of light exposure, the magnitude of the light-induced signal reaches a plateau, thereby implying the saturation of the phototransfer process. (author).

UK PubMed Central (United Kingdom)

γ-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated...Full Text Available

Science.gov (United States)

The three mammalian transforming growth factor (TGF)-? isoforms (TGF-?1, TGF-?2, and TGF-?3) differ in their putative roles in radiation-induced fibrosis in intestine and other organs. Furthermore, tissue specificity of TGF-? action may result from temporal or spatial changes in production and/or activation. The present study examined shifts in the cell types expressing TGF-? mRNA relative to TGF-? immunoreactivity and histopathological injury during radiation enteropathy development. A 4-cm loop of rat small intestine was locally exposed to 0, 12, or 21-Gy single doses of x-irradiation. Sham-irradiated and irradiated intestine were procured 2 and 26 weeks after irradiation. Cells expressing the TGF-?1, TGF-?2, or TGF-?3 transcripts were identified by in situ hybridization with digoxigenin-labeled riboprobes. Intestinal wall TGF-? immunoreactivity was measured using computerized image analysis, and structural ...

International Nuclear Information System (INIS)

The main aim of any food irradiation treatment is to guarantee the best safe quality of the products, reducing the spreading risk ("cross-contamination") for several food-associated diseases. Actually, over 40 countries provide clearances for the treatment of about 45 different types of foodstuffs. EU has to homogenise the situation within the associated States. With the European directive 1999/2/EC Italy, as other EU countries, already has brought into force their regulations to comply. The current Italian regulation on irradiation treatment of foodstuffs is referred since 1996 as follows: a) potatoes, onions and garlic; b) spices, herbs and condiments microbial. The new (April 2001) Italian law allows the possibility to ask for special permission of treatment for other foodstuff which is possible to treat in other E.U. countries. Large majority of foods are submitted to irradiation treatment after they have been packaged. In Dutch cases the study of ...

International Nuclear Information System (INIS)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used.

UK PubMed Central (United Kingdom)

Hundreds of thousands of people worldwide live or work in close proximity to steel mills. Integrated steel production generates chemical pollution containing compounds that can induce genetic damage...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural ...

International Nuclear Information System (INIS)

The effect on an oscillator moving in a medium produced by that part of the radiative force which does not perform work but creates and angular moment is considered. It is shown that the radiative torque turns the dipole toward the axis along which it is moving. Near the axis of motion the dipole executes small oscilltions. The frequency of the oscillations is determined. This effect leads to spontaneous alignment of the dipole moments on moving through the medium. The feasibility of observing the effect experimentally is discussed.

Energy Technology Data Exchange (ETDEWEB)

Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)

Energy Technology Data Exchange (ETDEWEB)

This paper describes the research and development activities in three areas of radiation processing, namely: food irradiation, medical product sterilization and wood plastic combination. Plans and efforts exerted to acquire a larger gamma source to augment our present 5,000 curie source are discussed. Cost estimates for a radiation facility are presented on the basis of the market potential of food irradiation and medical product sterilization. Existing local industries that can benefit from the adaptation of irradiation technology in their processing requirements are described.

International Nuclear Information System (INIS)

In areas where radiation dose monitoring has not been performed, it is essential to use material available in the environment be able to rapidly assess doses to individuals for immediate emergency medical care or for general estimation of the radiological consequences. It was shown that certain types of telephone cards containing microchips have the potential to be used as individual radiation dosimeters in emergency situations to detect doses over 250 mGy by luminescence measurements. In order to understand the dosimetric properties of chip cards, the components obtained from INFINIEON Company at various stages of production were used for luminescence measurements. It is found that the protecting layer used above the chips so called 'globe top' is the main source of radiation induced signal in chip cards. The globe top produced by INFINIEON at that stage is found to contain SiO2 ...

UK PubMed Central (United Kingdom)

Epicuticular wax production was evaluated along the length of expanding leek (Allium porrum L.) leaves to gain insight into the regulation of wax production. Leaf segments from the...Full Text Available

International Nuclear Information System (INIS)

The data are analyzed on cumulative antiproton production on Be, Al, Cu, and Ta nuclei induced by 10 GeV protons. The analysis is carried out in the framework of the flucton quark fragmentation model.

Energy Technology Data Exchange (ETDEWEB)

The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, T. harzianum M{sub ...

International Nuclear Information System (INIS)

For an assessment of the future US spallation neutron source (SNS) target performance, radiation induced hardening and microstructural evolution were investigated as a function of ion dose for EC316LN stainless steel. Irradiation was carried out using 3.5 MeV Fe"+, 360 keV He"+, and 180 keV H"+ simultaneous ion-beams at 200 deg. C to simulate the damage, He and H production in the SNS target vessel wall. At low dose (< 1 dpa), the predominant defects were black dots whose number density saturated rapidly within a few dpa. This was followed by the evolution of interstitial loops whose number density saturated below 15 dpa. Although He-bubbles were not visible, severely scalloped loops suggested that the implanted He/H atoms existed in the form of small clusters. Comparison with reported neutron irradiation data showed that hardening and ductility loss occurred mostly in the black dot regime (< 1 dpa), but that good ...

International Nuclear Information System (INIS)

The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

UK PubMed Central (United Kingdom)

Purpose: This paper reviews and reassesses the internationally accepted niches or ‘targets’ in bone marrow that are sensitive to the induction of leukaemia and primary...Full Text Available

UK PubMed Central (United Kingdom)

IntroductionIrradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly...Full Text Available

UK PubMed Central (United Kingdom)

IntroductionRadiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Hungary has 10.7 million population in 100,000 km/sup 2/ territory. The gross national product is about $3,000 per capita per year. Hungary is a country with highly developed agriculture and medium degree developed industries. The Hungarian economy is an open economy because more than 40% of the national income is earned by export. The research and development works on various radiation processing have been performed for 25 years. In the Central Research Institute for Physics of the Hungarian Academy of Sciences, a laboratory was organized for the basic research of radiation chemistry and the moderator materials for nuclear reactors. Also the activities in the Central Research Institute for Chemistry, the Institute of Isotopes, the Research Institute for Plastics Industry, and the Central Research Institute for Food Industry are briefly reported. The largest radiation processing unit in Hungary is the ...

Energy Technology Data Exchange (ETDEWEB)

Monolithic N-channel junction field effect transistors (NJFETs) dc characteristics, small signal parameters and noise have been studied from 300 K down to cryogenic temperatures before and after irradiation with {sup 60}Co {gamma}-rays and fast neutrons (1 MeV). Radiation induced effects on dc parameters and noise are reviewed. Noise spectral density measurements performed at various temperatures have shown that the radiation induces a noise increase which is temperature and frequency dependent. (orig.). 14 refs.

Energy Technology Data Exchange (ETDEWEB)

The electronic structure of the clusters (V/sub 3/Si/sub 4/)/sup 12 -/, (Nb/sub 3/Sn/sub 4/)/sup 12 -/(Mo/sub 3/Ge/sub 4/)/sup 15 -/ in crystalline V/sub 3/Si, Nb/sub 3/Sn, Mo/sub 3/Ge compounds is calculated by the Extended Hueckel method. The influence of different types of radiation induced defects on the density of states at the Fermi level (the anti-site defects, the displacement of atoms in linear chains, the vacancy-interstitial type defects) is considered.

International Nuclear Information System (INIS)

Mass distribution in 28.5 MeV alpha particle induced fission of "2"3"2Th has been determined using gamma spectrometric technique. The chain yields of 24 different fission products covering both symmetric and asymmetric mass divisions were determined. The mass distribution was found to be asymmetric with peak positions at mass numbers 96 and 136 respectively while the peak to valley ratio was 3.86. The results are compared with the available literature on 14 MeV neutron induced fission of "2"3"5U. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Metal oxide semiconductor (MOS) integrated circuits, with the benefits of low power consumption, represent the state of the art technology for implantable medical devices. Three significant sources of radiation are classified as having the ability to damage or alter the behavior of implantable electronics; Secondary neutron cosmic radiation, alpha particle radiation from the device packaging and therapeutic doses(up to 70 G{gamma}) of high energy radiation used in radiation oncology. The effects of alpha particle radiation from the packaging may be eliminated by the use of polyimide or silicone rubber die coatings. The relatively low incidence of therapeutic radiation incident on an implantable device and the use of die coating leaves cosmic radiation induced secondary neutron single event upset ...

International Nuclear Information System (INIS)

The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable ...

Science.gov (United States)

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared ...

International Nuclear Information System (INIS)

Mutagenesis of Lupinus mutabilis was started at the UNA LM (Peru) to obtain mutants with low alkaloid content and early germination. Varieties SCG 25 and Lib 020 were irradiated with gamma radiation. The optimum dose for the SCG 25 variety was 15 Krad and for Lib 020 15 to 20 Krad. The relation between the plant height and radiation dose fits the quadratic polynomial model.

International Nuclear Information System (INIS)

The influence of RTA (Rapid Thermal Anneal) treatment on MOS radiation hardness is demonstrated and compared with classical furnace treatment. In the case of the RTA, the oxide trapped charge is found to depend on: (i) the anneal temperature as expected, data are in good agreement with a recently developed model of oxygen out-diffusion; (ii) the location across the wafer with a radial dependence, results could be related to stress induced by thermal gradient.

UK PubMed Central (United Kingdom)

The three mammalian transforming growth factor (TGF)-β isoforms (TGF-β1, TGF-β2, and TGF-β3) differ in their putative roles in radiation-induced fibrosis in intestine...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Two patients who developed large intracranial vessel occlusion after standard radiation therapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiation therapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiation therapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port was demonstrated radiographically and confirmed by pathologic ...

International Nuclear Information System (INIS)

The application of photopolymerisation (UV) and electron beams (EB) technologies in radiation rapid cure (PRC) processing is discussed. The chemistry associated with such reactions and the mechanisms of the processes are treated. The occurrence of concurrent grafting to substrate with radiation curing of films is shown to be an advantage in enhancing the properties of certain finished products. The parameters influencing the optimum grafting yield in such PRC processes are discussed. In many applications, the chemistry of such processes combined with the machine, specially for EB is shown. (author).

Energy Technology Data Exchange (ETDEWEB)

The transition radiation detector (TRD) for the D{Phi} experiment is currently in operation at Fermilab. Transition radiation production, which has been clearly observed in the collider data, makes the TRD a valuable tool to discriminate electrons and hadrons. We describe an algorithm based on the truncated energy, and illustrate its use for top signal and background. (authors). 7 refs., 6 figs., 2 tabs.

International Nuclear Information System (INIS)

The consumption of food products obtained in areas subjected to radioactive contamination as a consequence of a radiation accident appears to be the most significant source of irradiation for the population. At the same time, this route can be regulated very effectively. The regularities of contamination of agricultural production, peculiar features of internal dose formation in the population and the effectiveness of countermeasures in agriculture have been analysed using the experience of two major accidents in the former USSR - in the South Urals (Kyshtym accident) in 1957, and at the Chernobyl NPP in 1986. (Author).

International Nuclear Information System (INIS)

Feasibility of using sterile females for population suppression of Earias vittella (Fabricius) was evaluated by conducting studies on mating competitiveness of radiation sterilized females, both in individual pairs and in simulated large population conditions. Results showed that sterility induced by using a 10:1:1 ratio (sterile female: normal female: normal male) in single pair experiments and also in simulated large population conditions was more than 99.0 per cent. Release of radiation- sterilized females of E. vittella in natural populations has thus an excellent potential for population suppression. (author)

International Nuclear Information System (INIS)

Argon ions irradiation of 12% Cr steels and Fe/Cr alloys results in the hardening up to 10000 MPa. This value exceeds the hardening level even for martensitic transformation. Along with the increase of microhardness following irradiation the shape of X-ray graph of the affected materials changes considerable. Hardening value and behavior are determined by temperature radiation doze, preliminary ageing, extent of cold strain and alloying. The odserved phenomenon is supposed to be caused by irradiation-induced structural transformations. Reversibility of radiation hardening of the materials in question was observed.

International Nuclear Information System (INIS)

Formulae are derived for estimation of the effect of gamma beam divergence on the value of systematic and statistical components of the errors of density measurement in production of structural materials and products also in the process of exploitation of building structures and constructions. Engineering technique for choice of the distance between radiation source and object under test is developed for absorption radioisotope densimeter operating by the scheme of geometry of divergent beam with amplitude compensation of backscattered radiation effect. The assessment of radioisotope densimeter efficiency providing the error of density measurement prescribed at design stage

International Nuclear Information System (INIS)

Background: the fact that therapeutic irradiation can induce significant stenosis in the arteries of the head, neck, and chest, as welt as in the aorta and the iliac arteries, is familiar in daily practice and well documented in the literature. By contrast, radiation-induced renal artery stenosis seems to be a less widely known complication. Patients and methods: the sudden onset of medically refractory arterial hypertension and coma in a 27-year-old man is reported, who had been treated at age 20 with chemotherapy and radiotherapy for Ewing's sarcoma in the lumbar region. This treatment had been performed at the hospital of Sion, Switzerland in 2001. Also, the relevant literature from 1965 to 2007 is reviewed to underscore various aspects of this problem and to demonstrate the clinical relevance of renal artery stenosis as a potential long-term sequela of radiotherapy. Conclusion: radiation-induced renal artery stenosis ...

International Nuclear Information System (INIS)

Simulation irradiation experiments were carried out to investigate the formation processes and contribution to hardening of radiation-induced features in low alloy steels. Medium Cu (0.12 and 0.16%) and low Cu (0.03%) A533B steels were irradiated with 3 MeV Ni ions and 5 MeV electrons, and in KUR at 290degC. Irradiated steels were examined by three-dimensional atom probe, positron annihilation, high-resolution transmission electron microscopy and hardness measurements. Electron irradiation caused almost the same hardening as KUR irradiation in medium Cu steels under almost the same dose rate and dose conditions, whereas the formation of larger, denser and more Cu enriched clusters and smaller accumulation of single vacancies were confirmed for KUR irradiation. This indicated that cascade damage provides additional cluster nucleation sites to compensate for lower free point defect production. High dose rate Ni ion irradiation produced Mn-Ni-Si ...

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. The radiation-induced follicular atresia was taken place via an ...

British Library Electronic Table of Contents (United Kingdom)

The chemopreventive efficacy of turmeric has been established in experimental systems. However, its mechanism(s) of action are not fully elucidated in vivo. The present study investigates the mechanism of turmeric-mediated chemoprevention in 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis at 2, 4, 6, 10 and 12?weeks. Dietary turmeric (1%) led to decrease in DMBA-induced tumor burden and multiplicity, and enhanced the latency period in parallel, to its modulatory effects on oncogene products and various cellular responses during HBP tumorigenesis. DMBA-induced expression of ras oncogene product, p21 and downstream target, the mitogen-activated protein kinases were significantly decreased by turmeric during HBP carcinogenesis. Turmeric also diminished ...

International Nuclear Information System (INIS)

A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy ...

Science.gov (United States)

Our Universe is ruled by quantum mechanics and its extension quantum field theory. However, the explanations for a number of cosmological phenomena such as inflation, dark energy, symmetry breakings, and phase transitions need the presence of classical scalar fields. Although the process of condensation of scalar fields in the lab is fairly well understood, the extension of results to a cosmological context is not trivial. Here we investigate the formation of a condensate--a classical scalar field--after reheating of the Universe. We assume a light quantum scalar field produced by the decay of a heavy particle, which for simplicity is assumed to be another scalar. We show that during the radiation domination epoch under certain conditions, the decay of the heavy particle alone is sufficient for the production of a condensate. This process is very similar to preheating--the exponential particle production at the end of ...

Science.gov (United States)

Ionizing radiation is a standard treatment for various human solid tumors. However, several clinical studies showed that a significant proportion of patients undergoing radiotherapy for hepatocellular carcinoma (HCC) develop intrahepatic and extrahepatic metastasis. Understanding of radiation-induced cancer cell invasiveness and behavior is essential and of great important for developing suitable treatment strategies to contain cancer spread. Therefore, in this study we evaluated the effectiveness of using swept source optical coherence tomography (SS-OCT) to monitor the enhancement of HCC cell invasiveness by radiation. SS-OCT images were acquired and recorded to obtain three-dimensional data sets per four hours in 48 hours after irradiating HepG2 cells with 7.5 Gy. The cell migration behavior in three-dimensional tissue models was quantified from images of radiation-induced and sham-irradiated cells.

International Nuclear Information System (INIS)

In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m"-"2 day"-"1 biologically effective UV-B radiation (UV-B_B_E). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the ...

Energy Technology Data Exchange (ETDEWEB)

Effect of radiation dose and carbon nanotubes (CNT) on the mechanical properties of standard Malaysian rubber (SMR) was investigated in this study. SMR nanocomposites containing 1-7 phr CNT were prepared using the solvent casting method and the nanocomposites were radiated at doses of 50-200 kGy. The change in mechanical properties, especially, tensile strength (Ts), elongation at break (Eb), hardness and tensile modulus at 100% elongation (M{sub 100}) were studied as a function of radiation dose. The structure and morphology of reinforced natural rubber was investigated by FESEM, TEM and AFM in order to gain further evidence on the radiation-induced crosslinking. It was found that the Ts, M{sub 100} and the hardness of the SMR/CNT nanocomposites significantly increased with radiation dose; the elongation at break exhibited an increase up to 100 kGy, and a downward trend thereafter. ...

International Nuclear Information System (INIS)

The results of studies of radiation-thermocatalytic water decomposition in the 673-773 K temperature range in the presence of BeO and titanium Y-type zeolite are presented. It is found that radiation-thermocatalytic processes of hydrogen production from water are characterized by a lower activation energy (55.4 kJ/mole) as compared with thermocatalytic processes (88.4 kJ/mole). The radiation-thermocatalytic process rate in the presence of oxide systems is not an additive sum of rates of radiation-catalytic (at 296-300 K) and thermocatalytic processes of water decomposition. On the basis of obtained results the conclusion is made that during radiation-catalytic decomposition of water in a heterogeneous system BeO + H_2O the main contribution into this process is made by excitons, radiation-chemical yields of excitons and non-equilibrium ...

CERN Document Server

Analysis of the dynamics of the cavity radiation of a coherently pumped correlated emission laser is presented. The phase fluctuation and dephasing are found to affect the time evolution of the two-mode squeezing and intensity of the cavity radiation significantly. The intensity and degree of the two-mode squeezing increase at early stages of the process with time, but this trend changes rapidly afterwards. It is also shown that they increase with phase fluctuation and dephasing in the strong driving limit, however the situation appears to be opposite in the weak driving limit. This essentially suggests that the phase fluctuation and dephasing weaken the coherence induced by a strong driving mechanism so that the spontaneous emission gets a chance. The other important aspect of the phase fluctuation, in this regard, is the relaxation of the time at which the maximum squeezing is manifested as well as the time in which the ...

International Nuclear Information System (INIS)

Radiation hardening and radiation-induced chromium (Cr) depletion were related to intergranular stress corrosion cracking (IGSCC) response among various stainless steels (SS). Available data on neutron-irradiated materials were analyzed and correlations developed between fluence, yield strength, grain-boundary Cr concentration, and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 neutrons/cm"2 to 2.5 x 10"2"1 neutrons/cm"2) for IGSCC were documented. Variability often was consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats, suggesting a possible role for radiation-induced hardening (and microstructure) on cracking. However, isolated heats revealed a wide range of yield strengths (450 MPa to 800 MPa) necessary to promote IGSCC which could not be explained by ...

International Nuclear Information System (INIS)

A multi-group neutron-gamma cross-section library in DTF-IV format is supplemented with electron production matrix to generate a coupled neutron-gamma-electron library. This is realized by estimating the contributions from Compton scattering, pair production and photoelectric effect to the electron production cross-sections. A novel application of this new library, which involves transport of neutrons, gammas and electrons, for estimating the Compton current due to a pulse of radiation in air is discussed.

International Nuclear Information System (INIS)

The sterile insect release technique can often be improved by removal of females before release. Rearing efficiencies can also be increased if removal of the females occurs at early developmental stages. In order to begin to develop genetic sexing strains for the pink bollworm, Pectinophora gossypiella (Saunders), it was necessary to determine the best dosage of radiation for induction of viable sex linked recessive lethal mutations and to see if stocks containing induced sex linked lethals could be maintained in culture. Sex linked recessive lethal mutations can be detected by distorted sex ratios in the progeny of treated adults. However, in the pink bollworm, highly distorted sex ratios are common even in the absence of induced mutations. Therefore, a visible sex linked trait, purple eye, was used as a marker for the untreated X-chromosomes in crosses. Thus, the presence of a recessive sex linked lethal mutation ...

UK PubMed Central (United Kingdom)

Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage....Full Text Available

UK PubMed Central (United Kingdom)

It has become increasing clear that alterations in cellular metabolism have a key role in the generation and maintenance of cancer. Some of the metabolic changes can be attributed to the activation...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundClara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and...Full Text Available

UK PubMed Central (United Kingdom)

Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation....Full Text Available

UK PubMed Central (United Kingdom)

Purpose.To report the increased production of extracellular transforming growth factor β-induced protein (TGFBIp) by human corneal epithelial cells (HCECs) after induction...Full Text Available

International Nuclear Information System (INIS)

The study of imported ceramics found in Beirut and suspected to belong to north Syrian products will provide key evidence for the roles in trade of the various postulated centers in northern Syria and northern Lebanon. It is proposed that a comprehensive range of likely north Syrian products imported to Beirut will be chemically analyzed by PIXE (proton induced X-ray emission) in order to characterize, compare and isolate the various regional production centers that supplied the city from the Persian to Byzantine periods. In this work, we were mainly focusing on the characterization of Amrit products, by using 3 MeV proton beam and Al funny filter, as X-ray absorber.

International Nuclear Information System (INIS)

Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives and is highly efficient. Its dose requirement is moderate. Radiation doses of 3-10 kGy (0.3-1 mrad) have proved sufficient to reduce the viable counts to a satisfactory level. Ionising radiations do not cause any significant rise in temperature. The flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for satisfactory decontamination, and radiation obviates the chemical residue problem. The microflora surviving radiation decontamination of dry ingredients are more susceptible to subsequent antimicrobial treatments. Recontamination can be prevented as the ...

Energy Technology Data Exchange (ETDEWEB)

The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author). 18 refs., 6 figures.

Energy Technology Data Exchange (ETDEWEB)

We have observed significant differences in the response to ionizing radiation of two closely related human cell lines, and now compare the effects on these lines of both low and intermediate LET radiation. Compared to TK6, WTK1 has an enhanced X-ray survival, and is also more resistant to cell killing by {alpha}-particles. The hprt locus is more mutable in WTK1 than in TK6 by both X-rays and {alpha}-particles. WTK1 is also more mutable by {alpha}-particles than by X-rays at the hprt locus. X-ray-induced mutation at the heterozygous tk locus in WTK1 is about 25 fold higher than in TK6, while {alpha}-particle-induced mutation is nearly 50 fold higher at this locus. Also, the slowly growing tk- mutants, which comprise the majority of spontaneous and X-ray-induced tk- mutants of TK6, were not induced significantly by {alpha}-particles. Previously, we showed that ...

International Nuclear Information System (INIS)

The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluted from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of #gamma#-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed. (author).

British Library Electronic Table of Contents (United Kingdom)

The formation of nanoparticles during the radiation-induced chemical reduction of silver ions, copper ions, and nickel ions in films based on poly(acrylic acid)-poly(ethylenimine) complexes are studied via electron microscopy. This approach allows preparation of composites containing nanoparticles that are randomly distributed in the polymer matrix and materials with a regular spatial distribution of nanoparticles across the film thickness and in subsurface layers. The structure of metal-polymer hybrid materials is dependent on the irradiation conditions, the type of reduced metal ions, and their initial content in polymer matrices. The ratio between the rate of nucleation and the rate of growth of nanoparticles in the matrices of interpolyelectrolyte complexes depends on the intensity of ...

Energy Technology Data Exchange (ETDEWEB)

Thermoluminescence (TL) properties of sphene and epidote are of interest in studies related to their radiation damage. Natural and artificially induced TL of these minerals has, therefore, been investigated. Both minerals exhibit complex glow curves with several overlapping peaks. The Tsub(m) -Tsub(STOP) thermal cleaning procedure has revealed three peaks in the ..gamma.. ray induced glow curve of each mineral. That these peaks obey second order kinetics was indicated by the continuously slanting structure of the Tsub(m)-Tsub(STOP) curve. The TL parameters E and s have been calculated using (i) the initial rise method, and (ii) the glow-peak shape method. In general, the values of E calculated by the first method are found to be higher than those from the second. The TL curve-fitting method is also applied in order to calculate these parameters and to serve as a cross-check on the results.

International Nuclear Information System (INIS)

In its 1990 recommendations, the ICRP considered the radiation risks after exposure during prenatal development. This report is a critical review of new experimental animal data on biological effects and evaluations of human studies after prenatal radiation published since the 1990 recommendations. Thus, the report discusses the effects after radiation exposure during pre-implantation, organogenesis, and fetogenesis. The aetiology of long-term effects on brain development is discussed, as well as evidence from studies in man on the effects of in-utero radiation exposure on neurological and mental processes. Animal studies of carcinogenic risk from in-utero radiation and the epidemiology of childhood cancer are discussed, and the carcinogenic risk to man from in-utero radiation is assessed. Open questions and needs for future research are elaborated. The report ...

Energy Technology Data Exchange (ETDEWEB)

Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. ...

Energy Technology Data Exchange (ETDEWEB)

Research on the feasibility of growing cattails as an energy crop is described. The following topics are included: productivity in natural strands, germination requirements for seed, establishing stands by seeding, rhizome dormancy and development, harvesting and stand establishment, and analysis of canopy structure and radiation profiles in a natural community. (MHR)

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

We have performed molecular dynamics simulations of radiation damage in fused silica. In this study, we discuss the role of successive cascade overlap on the saturation and self-healing of oxygen vacancy defects in the amorphous fused silica network. Furthermore, we present findings on the topological changes in fused silica due to repeated energetic recoil atoms. These topological network modifications consistent with experimental Raman spectroscopic observation on neutron and ion irradiated fused silica are indicators of permanent densification that has also been observed experimentally.

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)

In the Aqueous Self-Cooled Blanket (ASCB) concept, an aqueous "6Li solution in a metallic structure is used as a shielding-breeding blanket for fusion reactors. The experimental results of this study indicate that the radiolytic gas production in an ASCB will be proportional to the absorbed radiation energy. The observed radiation chemical yields allow the preliminary estimation of the radiolysis effects for a specific ASCB design. Contrary to the theoretical predictions, the use of hydrogen as a cover gas at up to 1 MPa had no measurable effect on the radiolytic gas production. Probably it will thus not be possible to suppress the radiolytic decomposition of a low-pressure ASCB by the addition of hydrogen. Catalytic recombination will be required. (orig.).

International Nuclear Information System (INIS)

Practical procedures were developed for large-scale microbial decontamination of dry egg powder and gelatine with gamma radiation ("6"0Co). The formation and lifes of free organic radicals in these materials were examined by ESR measurements of powder samples. The concentration of these radicals was studied in dependence on the time of storage. Secondary oxidation of egg fats by air oxygen was investigated. Sensoric tests of irradiated gelatine, both in powder and hydrogel form, were performed. (author). 4 figs., 2 tabs., 2 refs.

Energy Technology Data Exchange (ETDEWEB)

Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the reaction at the interface is radiation-enhanced.

Energy Technology Data Exchange (ETDEWEB)

We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-{beta}-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs ...

International Nuclear Information System (INIS)

The "1"2C induced fission of "2"0"9Bi at particle energy of 84.2 MeV has been studied using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The charge distribution has also been studied and the relative fractional cumulative yields of "9"2Y, "9"7Zr, "9"9Mo, "1"0"1Mo, "1"0"5Rh, "1"1"2Pd and "1"1"7"mCd determined. The yield distribution of fission products has been found to be broad (FWHM #approx =# 18) with a peak near mass #approx =# 105. (author). 7 refs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

Using longitudinal data from Ukraine we examine the extent of any long-lasting effects of exposure to the Chernobyl disaster on the health and labour market performance of the adult workforce. Variation in the local area level of radiation fallout from the Chernobyl accident is considered as a random exogenous shock with which to try to establish its causal impact on poor health, labour force participation, hours worked and wages. There appears to be a significant positive association between local area-level radiation dosage and perception of poor health, though much weaker associations between local area-level dosage and other specific self-reported health conditions. There is also some evidence to suggest that those who lived in areas more exposed to Chernobyl-induced radiation have sig...

British Library Electronic Table of Contents (United Kingdom)

Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.

International Nuclear Information System (INIS)

The first part of the study contains a literature compilation of more than 50 original publications reporting the radiation induced effects in 17 different high polymer materials and glass which are relevant in the manufacturing of medical devices or packing materials. The results collected demonstrate that high energy radiation, i.e. gamma- or X-rays, causes various physical and chemical alterations in high polymer materials. A detailed summary and discussion of the results of the original publications is not included in the present report, it will be presented in the second part of the study. Furthermore, the second part of the study will refer to the aspect of wholesomeness of irradiated medical devices or packing materials in a more general manner of representation. (orig.).

International Nuclear Information System (INIS)

Nickel ion radiation at 500 C was shown to have a strong effect on the surface electrochemistry and intergranular corrosion (IGC) of stainless steel (SS). Measured current densities in a 1 N sulfuric acid solution at room temperature were increased at active-passive, passive, and transpassive potentials. Radiation effects on the current decay behavior and susecptibility to IGC were similar for a fine-grained (FG) S alloy and for a very large-grained (LG) SS. Radiation-induced segregation (RIS) at the surface was believed to promote higher currents at short times, whereas segregation at grain boundaries was responsible for IG attack. Analytical electron microscopy (AEM) measurements revealed chromium and iron depletion plus Ni and silicon enrichment at grain boundaries in irradiated specimens. Si enhanced dissolution at transpassive potentials, whereas Cr depletion did the same at active-passive and passive potentials.

International Nuclear Information System (INIS)

Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) "6"0Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) "6"0Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical ...

International Nuclear Information System (INIS)

It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.

International Nuclear Information System (INIS)

Phospholipid vesicles were found to be lysed by exposure to free radicals derived from irradiated glycine and galactose. The decomposition yield increased with vesicle concentration, and attained values of 0.0006 vesicles destroyed per radical added. Ionic charge at the phospholipid end groups was found to be more important than degree of unsaturation in determining this yield. Radicals derived from irradiated serine and alanine had no detectable lytic action at the vesicle concentrations tested.

Energy Technology Data Exchange (ETDEWEB)

Occupational and environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls are linked with increased risk of hematologic malignancies. DOE facilities and waste sites in the U.S. are contaminated with mixtures of potentially hazardous chemicals such as metals, organic ligands, solvents, fuel hydrocarbons, polychlorinated biphenyls and radioactive isotopes. A major goal of this project was to establish linkage between chemical/radiation exposure and induction of genomic damage in target populations with the capability to undergo transformation.

International Nuclear Information System (INIS)

The application of robotics for repair, refurbishing or dismantling of nuclear installations implies eventually severe radiation resistance requirements on embarked components and subsystems. This is particularly critical when optical sensing is considered. Optoelectronic components and optical fibers are indeed quite sensitive to radiation, and without special design are rapidly out-of-operation in such an environment. This paper reports the results of a series of #gamma# irradiation experiments on such devices, and identify their behavior under radiation. Test results show that carefully selected optical fibers can keep their radiation induced attenuation lower than 0.3 dB/m even up to a total dose of 10 MGy. Temperature annealing can even lower this attenuation down to 0.1 dB/m. On the other hand, commercially available light emitting diodes and photodiodes present attenuations ...

International Nuclear Information System (INIS)

Poly(lactic acid) (PLA) is attractive as a substitute for classical polymer packaging material due to its biodegradability and sufficient mechanical and barrier properties. Presented research was focused on the changes of basic mechanical parameters after ionizing irradiation performed with doses in the range of 2.5-25 kGy, commonly used in radiation sterilization and preservation of foods. Two commercial available PLA packaging films were tested. The influence of radiation dose on the mechanical properties - tensile strength and elongation were determined using standardized methods. Radiation resistance of PLA is sufficient for packaging applications. The investigations of gas products of radiolysis of PLA have been made by gas chromatography after electron beam (EB) irradiations. (authors)

International Nuclear Information System (INIS)

This paper reports regulation of hypoxia inducible factor-1 ? (HIF-1 ?)in hepatoma cells by irradiation. Cobalt chloride (CoCl2), a chemical mimic agent for hypoxia research, was utilized to induce the stable expression of HIF-1 ? in HepG2 cells. The HepG2 cells were irradiated to different doses to observe the changes of HIF-1 ?. The level of intracellular reactive oxygen species (ROS) was assayed by fluorescent microscope and flow cytometry (FCM). The results showed that there were obvious changes in expression of HIF-1 ? after HepG2 cells exposed to radiation, and the changes were positively related with the irradiation dose from 1 Gy to 5 Gy. Moreover, contents of incellular ROS were negatively correlated with above levels of HIF-1 ? from 1 Gy to 3 Gy. The results indicate that irradiation may enhance hypoxic cells HIF-1 ?, and the reduction of intracellular ROS can contribute to the regulation of ionizing ...

International Nuclear Information System (INIS)

The "1"3"1-radioiodine use in Guanabara area, during 1972-1973, is analysed. References are made to the radiation levels delivered to thyroid, bone marrow and gonads in a population of 27000 people examined by tracer techniques, 190 submitted to hyperthyroidism treatment and 50 treated for thyroid cancer. The pertinent literature gives some data concerning radiation induced cancer (leukaemia and thyroid cancer). By this, it was possible to estimate the probability of tumour occurrence in that population, assuming a linear relationship between dose and effect. The conclusions are the followings: 1 - there are many duties in this field at the present; 2 - the leukaemia incidence related to the 131-radioiodine use is negligible, either in diagnostic or therapeutic modalities; 3 - the possibility of thyroid tumors induced by radiation is real, specially in hyperthyroidism treatment; 4 - ...

International Nuclear Information System (INIS)

Microbiological comparison between irradiated and non-irradiated foodstuff has been studied for a long time as a way to detect whether a foodstuff has been irradiated or not. Generally, the proposed methods are based on the fact that ionization select species of bacteria which are recognized to be radioresistant. So reduction or elimination of known radiation sensitive microbes from the normal endogenous microflora could give an indication that the foodstuff has been irradiated, predominance of known radioresistant bacteria should be another indication. In the present work, we try to develop a test based on the radiosensitivity of the bacteria independently of their place. These first experiments show that the determination of radiosensitivity of strains isolated from a product or even of global radioresistance of mesophilic microflora could indicate if this product has been previously submitted to ionizing ...

International Nuclear Information System (INIS)

The manufacture and use of wood/plastic composite (WPC) as an example of wood matrix and wood sawdust/plastic composites (SDP) as an example of plastic matrix are reviewed. The raw material for WPC are mostly vinyl monomers, particularly methyl methacrylate and styrene. The reaction in WPC polymerization is radical polymerization. Researches on the radiation sources mostly resulted in gamma-ray. Electron beam can be applied only to thin products. The future use of WPC may be for furnitures, sporting goods, decorative parts and the like. Vital study on the reduction of manufacturing costs is required, for example, the improvement of reaction and the adoption of continuous process must be considered. The raw materials for SDP are wood sawdust, vinyl monomer (mostly methyl methacrylate) and resins. Electron beam accelerators are the most preferable radiation source because of its high efficiency and safe operation. SDP shows ...

International Nuclear Information System (INIS)

Possible anomalous top-quark couplings induced by SU(2)xU(1) gauge-invariant dimension-6 effective operators were studied in the process of ttbar productions and decays at polarized #gamma##gamma# colliders. Two CP-violating asymmetries, a linear-polarization asymmetry and a circular-polarization asymmetry, were computed including both non-standard ttbar#gamma# and #gamma##gamma#H couplings. An optimal-observable analysis for the process #gamma##gamma##->#ttbar#->#l"#+-# was performed in order to estimate the precision for determination of all relevant non-standard couplings, including the anomalous tbW coupling.

Energy Technology Data Exchange (ETDEWEB)

Oxygen-16 induced fission studies of [sup 209]Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM [approx equal] mass units) with a peak near mass [approx equal] 108. The charge distribution in the [sup 16]O ion induced fission of [sup 209]Bi has also been studied at particle energy of 89.5 MeV. The relative cumulative yields of [sup 92]Sr, [sup 97]Zr, [sup 99]Mo, [sup 101]Mo, [sup 112]Pd and [sup 117m]Cd have been determined using gamma ray spectrometry. The width of charge distribution has been found to be broad. (orig.)

International Nuclear Information System (INIS)

The "1"6O induced fission studies of "2"0"9Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM=16) with a peak near mass 107. The charge distribution in the "1"6O particle induced fission of "2"0"9Bi has been studied at "1"6O particle of 89.5 MeV. The fractional cumulative yields of "9"2Y, "9"7Zr, "9"9Mo, "1"0"1Mo, "1"0"5Rh, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. (author). 7 refs., 2 tabs.

Science.gov (United States)

Asynchronous Chinese hamster ovary (CHO) cells treated with conditioning hyperthermia (10 min at 45/sup 0/C) followed immediately by x irradiation with 4 Gy at room temperature display a decreased radiation response when either irradiated, or heated and irradiated again 24 h later. In addition, conditioning by 4 Gy of x radiation alone followed at 24 h by the combined heat and radiation treatment als resulted in a larger radiation D/sub 0/. Since the differential cell-cycle responses to heat- and x-ray-induced lethality are well established for CHO cells, the potential role of cell-cycle redistribution in the observed radiation desensitization was investigated by flow cytometry. At 24 h after the combined treatment, the fraction of the cells found in the G/sub 2/ + M portion of the DNA histograms was about three times that of the controls and there was a ...

International Nuclear Information System (INIS)

We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al0, Al+ and Al++). The calculations were carried for stationary plasmas, with input parameters (ne and Te) ranging respectively between 1013-18 cm-3 and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Strains of Pseudomonas syringae are effective in controlling postharvest diseases of citrus fruits, and antagonistic activity has been correlated with in vitro production of lipodepsipeptides. Additionally, biocontrol agents can induce a range of defence mechanisms of resistance in citrus tissue that result in a broad spectrum of metabolic modifications, such as systemic acquired resistance, induced systemic resistance and production of reactive oxygen species. The aim of this study was to evaluate the expression of syringomycin (syrB1) and syringopeptin (sypA) synthetase genes from P.syringae pv. syringae biocontrol strains in vitro on different culture media and in vivo on citrus fruits (Citrus sinensis cv. Tarocco) during the interaction with Penicillium digitatum by quantitati...

International Nuclear Information System (INIS)

The alpha particle induced fission of "2"0"9Bi has been investigated for E_#alpha# = 55.7 and 58.6 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The mass distributions have been found to be broad with a peak near mass 104. The charge distribution has been studied at the same particle energies. The fractional cumulative yields of "9"7Zr, "9"9Mo, "1"0"1Mo, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. The width of charge distribution is broad. (orig.).

International Nuclear Information System (INIS)

In the use of doxorubicin and radiation for treatment of human malignant tumors in vivo, the relationship between treatment-induced apoptosis and Ki-67 labeling index was investigated. Four human tumor xenografts (ependymoblastoma, NNE; primitive neuroectodermal tumor, YKP; small cell lung carcinoma, GLS; glioblastoma, KYG) were transplanted under the skin of thigh of the nude mice (BALB/cA JcL-nu). The mice were given a single radiation dose of 1 Gy, or doxorubicin alone intraperitoneally at a dose of 8 mg/kg. After treatment, sections of tumor specimens were prepared from paraffin-embedded tissues. Hematoxylin and eosin staining, TUNEL staining, and immunohistochemical analysis of Ki-67 were performed. In NNE, apoptotic cells appeared most frequently after treatment compared with all other tumors, and the incidence of apoptosis in the radiation-treated group was much higher than in the ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to analyze the safeties and the economics for Co-60 production from Wolsung PHWR and to verify the feasibility on the manufacturing of the final Co-60 source for industrial irradiation. The feasibility of reactor conversion was carried out with KEPCO collaboration. Through the site survey on the experience of Gentililly-2 in Canada, a feasibility of plant conversion, changes in design, equipment and tools for Co-60 production was verified. It was estimated that the reactor conversion would not impose adverse impact on plant safety. For the encapsulation of radiation source and storage of the final products, a modification of concrete hot cell at KAERI was primary concerns. The installation and improvement of facilities are needed to avoid cross contamination and extra radiation exposure. Main items for these are pressure gauge, separated HEPA filter the ...

International Nuclear Information System (INIS)

Generally, neutron, ion and electron Irradiations cause a substantial amount of hardening and significantly alter the deformation behavior of metals and alloys at relatively low irradiation temperatures. A radiation hardening is caused by the formation of microstructural defects such as dislocation loops, voids and precipitates under irradiation. Therefore, it is important to have a better knowledge of the irradiation induced microstructural defects under irradiation condition. As a part of the National mid- and long-term atomic energy R and D program, we are dealing with the radiation hardening behavior in Fe-Cr binary alloy. Fe-Cr binary alloy is a base alloy of Ferritic/Martensitic steel(F/M steel) planning to use for the Gen IV nuclear system. In this work, we investigated the radiation hardening and microstructural defect evolution in ion irradiated Fe-Cr alloys with irradiation temperature using ...

International Nuclear Information System (INIS)

Wood plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, and with Okoume (aucoumea klaineana pierre) imported to Syria in large quantities. Three monomer systems; acrylamide, butylmethacrylate, and styrene were used. polymerization was induced at various radiation doses (10, 20, and 30 kGy) to study the role of radiation doses using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength or tensile strength of the obtained wood polymer composites (WPC) were studied. The effect of the additives, sulfuric acid (H"+), N-vinyl pyrrolidone (NVP), trimethyolpropane triacrylate (TMPTA), urea (U), lithium nitrate (LiNo_3), copper sulfate (CuSO_4) and co-additives on monomer system polymerization were also investigated. Methanol, water and water/methanol mixtures were used as the swelling agents. In general, the use of ...

Energy Technology Data Exchange (ETDEWEB)

The D2 antidopaminergic drug Domperidone was evaluated singly and in combination with synthetic adrenocorticoid and an H2 antihistamine for its ability to reduce the acute emetic effects of /sup 60/Co whole-body radiation. Random-source adult male dogs were fasted 12 hours, fed a standard meal, injected 44 minutes later and irradiated 47 minutes after that. Four groups of dogs were radiated after drug injections as follows: saline (Con), domperidone (Dom), cimetidine + thiethylperazine (Cim+Thi), and dexamethasone + domperidone + cimetidine (Dex+Dom+Cim). Drug quantities for dogs represented 10 mg Dom, 10 mg Thi, 20 mg Dex, and 300 mg Cim for an average human (70 ka, 1.8 m2). Subjects were exposed on an up-down schedule to determine the radiation necessary to produce vomiting in 50% (ED50) of each group. Emesis onset times, offset times, and number of episodes were recorded. The ED50 of Dex+Dom+Cim was higher than Con. Dom ...

Energy Technology Data Exchange (ETDEWEB)

In principle four different methods (ultrasound, microwaves, {gamma}-radiation and x-rays) are available for the non-destructive testing of refractories. Three of these methods, i.e. ultrasound, microwaves and {gamma}-radiation, are in use by different producers of AZS materials to carry out the quality control of their products. This paper will compare the three methods on the basis of the physical properties, present the existing devices, and show the advantages as well as the limits of the different methods. {gamma}-radiography, the oldest method in use, has one main disadvantage, which is the requirement of protection against radioactive radiation. Furthermore, while cracks and cavities can be detected with this method, structural changes can not be monitored. Therefore, the ultrasonic method was developed that allows to detect variations of porosity and grain size as well as cracks and voids when ...

International Nuclear Information System (INIS)

The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.

International Nuclear Information System (INIS)

The foils of various materials were irradiated with "6"0Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.).

International Nuclear Information System (INIS)

On 21 October 1994, three brothers entered a waste repository at Tammiku, Estonia, without authorization and removed a metal container enclosing a caesium-137 source. During the removal the source was dislodged and fell to the ground. One of the men picked up the source, placed it in his pocket and took it to his home in the nearby village of Kiisa. Very soon after entry into the repository he began to feel ill, and few hours later he began to vomit. The man was subsequently admitted to hospital with severe injuries to his leg and hip and died on 2 November 1994. The injury and subsequent death were not attributed to radiation exposure, and the source remained in the man's house with his wife and stepson and the boy's great-grandmother. The boy was hospitalized on 17 November with severe burns on his hands, and these were identified by a doctor as radiation induced. The authorities were alerted, and the Estonian Rescue ...

Energy Technology Data Exchange (ETDEWEB)

We present production rates of the two- and three-jet final states for the processes of massive cc/bb quark production in circularly polarized photon-photon collisions, including QCD radiative corrections. Lowest-order cross section, one-loop virtual correction, and gluon emission correction are shown to be of the same order of magnitude for bb quark production at s{sub {gamma}{gamma}} similar 100 GeV. It is shown that the signal from an intermediate mass Higgs boson is observable at a photon-photon collider, though the statistical significance is substantially reduced with respect to the tree-level calculation. ((orig.)).

International Nuclear Information System (INIS)

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. The uncertainty of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain fissioning isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry. (author)

International Nuclear Information System (INIS)

The concepts of ''fast'' and ''slow'' time scale valence measurements are emphasized by a comparison of L/sub III/ absorption and Mossbauer effect measurements on the temperature induced valence change in EuPd/sub 2/Si/sub 2/. Further the authors show how synchrotron radiation based L/sub III/ measurements of the Ce-valence state can be used to demonstrate electronic structure trends under wide changes in chemical environment. The purpose of this paper is to provide an introduction to researchers in the People's Republic of China to the field of mixed valent rate earth compounds. They hope to illustrate some of the basic concepts in this field, how the field is contributing to the overall insight into the chemical physics of solids and finally how synchrotron radiation measurements in particular are playing a key role in this field.

CERN Document Server

We study spontaneously generated entanglement (SGE) between two identical multilevel atoms in free space via vacuum-induced radiative coupling. We show that the SGE in two-atom systems may initially increase with time but eventually vanishes in the time scale determined by the excited state lifetime and radiative coupling strength between the two atoms. We demonstrate that a steady-state SGE can be established by incoherently pumping the excited states of the two-atom system. We have shown that an appropriate rate of incoherent pump can help producing optimal SGE. The multilevel systems offer us more chanel to establish entanglement. The system under consideration could be realized in a tight trap or atoms/ions doped in a solid substrate.

Energy Technology Data Exchange (ETDEWEB)

Long before possible organic effects, exposure to ionizing radiations can provoke anxiety. In front of invisibility, the imagination quickly ignites. The terrorists have perfectly understood it. They are ready to use ionizing radiations as a weapon to remind traumatic images deeply rooted in people's memory. These images induce anxiety with all the clinical expressions connected to it. These symptoms require to be treated because of a possible anarchic development. For that purpose, plans have been elaborated to coordinate the different professional's actions. The coherence of medical management and communication aims to allow the most implicated people to find the way to face the events. When it is not possible, medico-psychological cells permit a specialized care. (author)

Science.gov (United States)

Summaries are included of research contracts which expired prior to Dec. 31, 1960. The contracts were concerned with investigations of: electrophysiological responses of biological systems in nerve cells to irradiation with small doses of ionizing radiations; the mode of the protective action of certain sulfhydryl compounds against radiation effects on the synthesis of deoxyribonucleic acid, using tritium-labeled thymidine; development of a bubble chamber method of monitoring and dosimetry for Low fast neutron fluxes; effects of incorporated radioisotopes on the stability of genetic materials; interrelation of root and leaf absorption of radioisotopes in herbaceous plants; uptake of radioactive wastes by lowland rice from soils contaminated by irrigation water, and decontamination of the rice; and comparison between mutation rates induced by acute and chronic gamma irradiations. (B.O.G.)

British Library Electronic Table of Contents (United Kingdom)

Temperature variations due to climate changes are a major cause of movements in a concrete structure, both in the longitudinal and transversal directions and between different parts of the structure. If these movements are restrained, stresses will be induced which may contribute to cracking. The movements are caused by complex interactions of several factors such as solar radiation, air temperature, long-wave heat radiation and wind speed. To predict the varying thermal conditions in a concrete structure a finite element model has been used. A validation of the model has been performed using field measurements in a concrete slab together with climate data from the Swedish Meteorological and Hydrological Institute to be able to use the model for simulations over long time periods and for s...

International Nuclear Information System (INIS)

The effect of exposure to gamma rays on LPO contents in liver, spleen and kidney of mice and the anti-lipid-peroxidation of preparations of chinonin, tannic acid and squalene were reported. All these preparations were given by intragastric perfusion. For LPO, a modified method of TBA spectrophotometry was used for determination. The results show that LPO contents in tissues increased 72 h after whole-body exposure of mice to gamma rays, that in range of 0-4 Gy, there was a linear relationship between radiation doses and LPO contents, and that all three preparations were effective in reduction of the LPO content in liver, spleen and kidney of mice, with chinonin (at dose of 0.35 mg/mouse#centre dot#day) being more effective than tannic acid (at dose of 15 mg/mouse#centre dot#day) and squalene (at dose of 0.6 mg/mouse#centre dot#day).

CERN Document Server

Radiation protection of the personnel who will perform interventions in the LHC Beam Cleaning Insertions is mandatory and includes the design of equipment and the establishment of work procedures. Residual dose rates due to activated equipment are expected to reach significant values such that any maintenance has to be planned and optimized in advance. Three-dimensional maps of dose equivalent rates at different cooling times after operation of the LHC have been calculated with FLUKA. The simulations are based on an explicit calculation of induced radioactivity and of the transport of the radiation from the radioactive decay. The paper summarizes the results for the Beam Cleaning Insertions and discusses the estimation of individual and collective doses received by personnel during critical interventions, such as the exchange of a collimator or the installation of Phase 2. The given examples outline the potential and the ...

International Nuclear Information System (INIS)

Population distribution, atmospheric change, X/Q, characteristics of terrestrial ecosystem around Seoul site were surveyed. Environmental radiation and radioactivities such as gross#alpha#, gross#beta#, Cs-137, Sr-90 and H-3 of various environmental samples were analyzed. The values of environmental radiation dose tended to increase gradually in the light of the recent five years' results of environmental radiation monitoring around the nuclear power plants from 1980 to 1984, however, the changes were not significant. In addition, continuous assessment of environmental radiation monitoring on the roofs of main building and life science building at KAERI showed that the environmental radiation dose tended to increase a little during the night time. Judging from the above results, it is concluded that environmental contamination level by radioactive materials could be ignored in the ...

International Nuclear Information System (INIS)

Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,?) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe8+. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe8+ transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)

British Library Electronic Table of Contents (United Kingdom)

In order to promote uniformity between jurisdictions, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has developed the National Directory for Radiation Protection, which is a regulatory framework that all Australian governments have agreed to adopt. There is a large and diverse range of industries involved in mining or mineral processing, and the production of fossil fuels in Australia. Enhanced levels of naturally occurring radionuclides can be associated with mineral extraction and processing, other industries (e.g. metal recycling) and some products (e.g. plasterboard). ARPANSA, in conjunction with industry and State regulators, has undertaken a review and assessment of naturally occurring radioactive material (NORM) management in Australian industries. This rev...

Energy Technology Data Exchange (ETDEWEB)

Using {gamma}-irradiation-induced reduction in the field of a {sup 60}Co {gamma}-ray source, colloidal silver and gold nanoparticles were prepared from their corresponding metal salts in aqueous solution and compared with those by chemical reduction. The radiation-based method provided silver nanoparticles with higher concentration and narrower size distribution than those obtained by chemical reduction method while there was no significant difference between the two strategies for the preparation of gold nanoparticles. {gamma}-Irradiation of 1.0 x 10{sup -3} M AgNO{sub 3} solution resulted in nearly 100 times more highly concentrated silver colloids than those by citrate reduction. Furthermore, the radiation method could lead to more highly concentrated silver colloids by simply increasing the concentration of AgNO{sub 3} solution up to 2.0 x 10{sup -2} M. The two metal nanoparticles prepared by the two different methods ...

Energy Technology Data Exchange (ETDEWEB)

Tensile specimens 60 ..mu..m thick of Ni-8 at. % Si have been bombarded at 475/sup 0/C to doses of 0.1 to 0.3 dpa with either 7 MeV proton or 28 MeV alpha particle beams. Deliberate embrittlement by high temperature (700/sup 0/C) preimplantation of helium was required to produce intergranular fracture. Depth profile sputtering and analysis in a Scanning Auger Microprobe was then used to study radiation-induced segregation of silicon both at the external surfaces and at internal interfaces. The external surfaces exhibited a strongly silicon-enriched zone for the first 10 to 20 nm followed by a broad (approx.200 nm), shallow silicon-depleted region. Segregation of silicon to grain boundaries varied from interface to interface and possibly from region to region on a given interface. In general, however, depth profiles of silicon content with distance from internal boundaries showed no noticeable depletion zone and a more gradual fall-off compared to the profiles from ...

Science.gov (United States)

We investigated possible mechanism(s) where honokiol induces apoptosis in human hepatocellular carcinoma SMMC-7721 cells. MTT assay showed that honokiol has strong inhibition on SMMC-7721 cells in a dose-dependent manner. SMMC-7721 cells after honokiol treatment display morphological characteristics such as cell shrinkage, detachment from the culture plate, formation of apoptotic bodies, change to a round shape, and marked nuclear condensation and fragmentation after 32258 staining. Cell apoptosis was measured by Annexin-V/PI staining and alternatively, by the subG0/G1 percentage of the cell cycle analysis followed by FACS. An obvious loss of ??(m) and a quick burst of ROS was detected when honokiol reached 4?g/ml, which was coincident with the high apoptosis percentage in our previous research. Up-regulation of Bax and down-regulation of Bcl-2 were observed, suggesting that honokiol-induced apoptosis was associated with reactive oxygen species ...

International Nuclear Information System (INIS)

An original evaluating method of gain degradation has been found for neutron irradiated transistors. It establishes a correlation between degradation and the product of two coefficients: spectra factor and an electrical parameter which is measured or directly deduced from manufacturer's data. Equivalence for several type of spectra (fission, 14MeV and degradation sensitivity to electrical parameters values of individual components of a batch are obtained.

UK PubMed Central (United Kingdom)

Hyperthermia (HT) is a strong adjuvant treatment with radiotherapy and chemotherapy because it causes tumor reoxygenation. However, the detailed molecular mechanisms of how HT enhances tumor oxygenation...Full Text Available

UK PubMed Central (United Kingdom)

IntroductionThe major risk factor for osteoarthritis (OA) is aging, but the mechanisms underlying this risk are only partly understood. Age-related accumulation of advanced glycation...Full Text Available

UK PubMed Central (United Kingdom)

The CNS is a unique organ due to its limited capacity for immune surveillance. As macrophages of the CNS, microglia represent a population originally known for the ability to assist neuronal stability,...Full Text Available

Science.gov (United States)

Pentaerythritol tetranitrate (PETN) is a relatively sensitive explosive used in many electroexplosive devices as well as in medicine. Of primary interest to LLNL is its use in items such as exploding bridgewire (EBW) detonators and exploding bridge foil initiators (EFI). In these devices the crystalline powder is pressed into a granular, low-density compact that can be initiated by an exploding wire or foil. The long-term stability of this pressed compact is of interest to weapon stockpile lifetime prediction studies. Key points about potential aging mechanisms can be summarized as follows: (1) There are a number of factors that can contribute to PETN instability. These include particle size, polymorphic phase transitions, crystal structure, impurities, moisture, occlusions, chemical incompatibility and biological (microorganism) action. of these factors the most important for long-term aging of high surface area powders used in detonators appears to be that of particle size growth. ...

Energy Technology Data Exchange (ETDEWEB)

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the ...

International Nuclear Information System (INIS)

Despite its great usefulness in the performance of the recording procedures prescribed by the X-Ray Ordinance the dose-area product is much less frequently measured for X-ray exposures than during fluorscopic examinations. The great multitude of measuring units, mainly on account of different scales of the measuring equipments themselves, is a cause of uncertainty in clinical routine and should be eliminated as far as the circumstances would permit. As the determination of the organ dose is relevant only in very few cases and does not necessarily require previous measurements of the dose-area product, these are of limited practical value in the assessment of individual radiation exposures during radiographic examinations. The measurements may, however, be very helpful in determinations of the radiation dose to the total population, if the future retrievability of the values obtained is ensured. In ...

International Nuclear Information System (INIS)

This is a preliminary study on the sound absorption properties of two tropical hardwoods, Light Red Meranti and Ramin, and their wood-polymer composites. Sound absorption is measured using a standing wave apparatus. The samples are of one thickness (7 mm) and cut longitudinally. Wood-polymer composites are made by impregnating the samples with methyl methacrylate which is polymerized in situ through #gamma#-irradiation. Both woods and their composites are better sound absorbers at higher sound frequencies. With partial impregnation, the absorption coefficients are improved upon particularly in the region between 1-3 kHz. (author).

International Nuclear Information System (INIS)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

Energy Technology Data Exchange (ETDEWEB)

Three possibilities to observe the Higgs-top interaction at future {gamma}{gamma}-colliders are discussed: (a) associated Higss production via the {gamma}{gamma}{yields}tanti tH reaction, (b) Higgs obliged radiative correction to the {gamma}{gamma}{yields}tanti t channel, (c) Higgs resonance production via {gamma}{gamma}{yields}H{yields}ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at {gamma}{gamma}-colliders. (orig.).

International Nuclear Information System (INIS)

Bases of the algorithm for assessing the reinforcement status in reinforced concrete products by gamma-absorption method are presented. Analytical equations are obtained for estimation of error of the parameter characterizing the degree of reinforcement destruction. It is recommended to use high-energy Bremsstrahlung sources-betatrons of 4-10 MeV maximum energy for testing products of 500-600 mm thick. Linear radiation attenuation factor (LAF) of concrete in estimated equation is replaced by effective LAF of concrete, and LAF of reinforcement and corrosion materials - by differential LAF. Corresponding LAF of nonevident form in the algorithm is assessed by the results of processing of direct-shadow radiographs of defectometers

International Nuclear Information System (INIS)

Purpose/Objective: The role of programmed cell death (apoptosis) as a cellular response to cancer therapy such as radiation or chemotherapy is the subject of much study, and manipulation of the apoptotic response in tumor cells may be valuable in the treatment of a variety of cancers. Both p53 dependent and independent apoptotic pathways have been identified; p53 is mutated in at least 50 % of human cancers and a majority of radiation resistant tumors contain p53 mutations. This study is designed to examine the induction of programmed cell death in a human colon carcinoma cell line that possesses two mutated p53 alleles. Ionizing radiation alone, or in combination with the chemotherapeutic drug 5-fluorouracil (5-FU), were used to elicit the apoptotic response. This study will focus on whether these treatments can induce a significant apoptotic response in cells that have mutated p53 alleles. Materials ...

International Nuclear Information System (INIS)

Experimental observations related to the initiation of plastic deformation in metals and alloys irradiated with fission neutrons have been analyzed. The experimental results, showing irradiation-induced increase in the upper yield stress followed by a yield drop and plastic instability, cannot be explained in terms of conventional dispersed-barrier hardening because (a) the grown-in dislocations are not free, and (b) irradiation-induced defect clusters are not rigid indestructible Orowan obstacles. A new model called 'cascade-induced source hardening' is presented where glissile loops produced directly in cascades are envisaged to decorate the grown-in dislocations so that they cannot act as dislocation sources. The upper yield stress is related to the breakaway stress which is necessary to pull the dislocation away from the clusters/loops decorating it. The magnitude of the breakaway stress has been estimated and is found ...

Energy Technology Data Exchange (ETDEWEB)

The electrical conductivity of Vitox-alumina (99.2%), Wesgo-alumina (99.9%) and AlN (99.6%) has been measured during and after irradiation with an experimental set-up which allows fusion relevant loading conditions. All irradiations were performed in high vacuum at 450 C using a 104 MeV {alpha}-particle beam with an applied DC electric field of 100 kV/m. In the high purity Vitox-alumina the in-situ and postirradiation bulk conductivities {sigma} and {sigma}{sub 0} show the highest irradiation induced electrical breakdown ever observed. The saturation level near 4 x 10{sup -2} ({Omega}m){sup -1}, reached already after 0.015 dpa (O-sublattice), is already above the critical value necessary to avoid MHD pressure drop with 10 {mu}m coatings in flowing liquid metal coolants. Under the same conditions no radiation induced electrical degradation at all has been found in Wesgo-alumina and AlN. (orig.).

International Nuclear Information System (INIS)

The behaviour of the packaging materials under radiation field has a great importance in radiation processing, because, in most cases, they are finally responsible for the preservation of the beneficent changes achieved in irradiated products. For example, in radiation sterilisation and food irradiation, the packages must preserve the sterilisation, respectively the sanitisation. They must preserve also the physical barrier feature. The radiation effects on plastics were extensively studied in the last decades for nuclear industry and more recently for radiation processing. The two major effects of nuclear radiation on polymeric materials are the degradation and cross-linking. The degradation consists in breaking of macromolecules after interaction with nuclear particles, amplified by the free radicals which persist long periods, especially ...

International Nuclear Information System (INIS)

Radiation sterilization has several merits that it is a positively effective sterilization method, it can be used to sterilize low heat-resistant containers and high gas barrier films, and there is no possibility of residual chemicals being left in the packages. It has been commercially used in 'Bag in a Box' and some food containers. The #gamma# ray and an electron beam are commonly used in radiation sterilization. The #gamma# ray can sterilize large size containers and containers with complex shapes or sealed containers due to its strong transmission capability. However, since the equipment tends to be large and expensive, it is generally used in off production lines. On the other hand, it is possible to install and electron beam system on food production lines since the food can be processed in a short time due to its high beam coefficient and its ease of maintenance, even though an electron beam has ...

International Nuclear Information System (INIS)

The most important factor in assessing radiologic risk is ensuring scientific means for evaluation of the radioactive release impact upon humans and organisms. To evaluate quantitatively this impact not only knowledge of radioactivity distribution in these dynamical systems is necessary but also understanding the transfer mechanisms between ecosystem components is needed. Thus a complete radioecologic study appear to be very complex and needs defining the source term, dynamic description of radionuclides behavior in the ecosystem, estimation of radiation doses in the major components of the ecosystem and finally the effects of radiation doses upon different parts of the systems. A diagram of the steps implied in evaluation of the effects due to radioactive effluent release in the environment is presented and discussed. The following steps are described: - identification of radioactive sources, as well as their input rate. Presence of noxious ...

Energy Technology Data Exchange (ETDEWEB)

Large-scale field tracer experiments have been conducted on Ulchin, Wolsung and Daeduk sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear sites. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. both processes, of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by ...

Energy Technology Data Exchange (ETDEWEB)

We report a patient who developed occlusion of the intracranial major arteries induced by radiation therapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiation therapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left carotid angiography ...

Energy Technology Data Exchange (ETDEWEB)

A fully quantized many-particle theory of the standard free-electron laser in the small-signal, cold-beam regime is presented. The approach is based on an evaluation of the time-evolution operator in the interaction picture to first order in the quantum-mechanical recoil. For algebraic convenience we use the moving (Bambini-Renieri) frame, in which resonance occurs for zero electron momentum. Though we neglect space-charge effects, genuine many-particle contributions still show up, because the radiation emitted by one electron can be amplified by another electron. Our main results are gross features of the amplification, such as gain and spread, are virtually without many-particle effects. These effects are mainly important in the case of spontaneous emission. For a sufficiently high current, the buildup of the laser field from vacuum is enhanced by amplified spontaneous emission. Incoherence of the spontaneous radiation from several electrons ...

Energy Technology Data Exchange (ETDEWEB)

The effects of gamma and e-beam irradiation on mechanical and structural properties of nylon 66 (Ny 66), nylon 6 (Ny 6) and poly(ethylene terephthalate) (PET) fabrics used in tyres were investigated. The untreated (greige), treated cords and calendered fabrics were irradiated at different doses. It is found that the effects of high energy irradiation on greige, treated cords and calendered fabrics are similar. No protective effect of compounds used in calendering was observed against radiation-induced oxidative degradation. The deterioration effect of gamma irradiation on mechanical properties is much higher than that of e-beam irradiation for all types of samples. Limiting viscosity numbers of both gamma and e-beam irradiated nylon 6 and nylon 66 cords were found to decrease with increasing dose. It is concluded that PET calendered fabric has higher resistance to ionizing radiation. Ny 6 and Ny 66 calendered fabrics are more sensitive even at ...

International Nuclear Information System (INIS)

Studies were conducted on mating behaviour and reproductive performance of a) Earias vittella (F.) males rendered sterile by exposing them to 300 Gy gamma rays and b) F_1 sterile males obtained by exposing parent male to 100 Gy gamma rays. For the study, males were allowed only one mating with a normal female. Results revealed that premating period, period in copula and per cent insects mating were not adversely affected in case of both types of sterile males and fecundity also remained unaffected. However, in both types of sterile males, incidence of spermatophore transfer without sperm was very large and such an occurrence (including reduced spermatophore transfer) was significantly higher in case of radiation sterilized males compared to the F_1 sterile males. Inability to produce and transfer spermatophore and/or sperm appeared to be a major cause behind the reduced mating competitiveness of both types of males. (author). 22 refs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

In August 1982, a 44-year-old man was diagnosed as having rectal cancer, histologically diagnosed as well differentiated adenocarcinoma, and abdominoperineal resection and colostomy were performed. Postoperatively, he received chemotherapy with mitomycin C up to a total dose of 100 mg. In September 1986, lung metastasis occurred and he was treated with a combination chemotherapy consisting of cisplatin, pirarubicin and 5-fluorouracil. In the following year, radiation treatment (total: 6900 rad) was given for a recurrent pelvic lesion. Peripheral blood on April 30, 1988, showed anemia, thrombocytopenia and appearance of myeloblasts, and a diagnosis of acute myelogenous leukemia (FAB: M1) was made. Combination chemotherapy (including aclarubicin, vincristine, behenoyl ara-C, daunorubicin, 6-mercaptopurine, cytarabine, etoposide and prednisolone) failed to induce remission and the patient died in June 1988. This case was thought to be one of ...

International Nuclear Information System (INIS)

Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives. (author) 1 tab.

International Nuclear Information System (INIS)

Radionuclide (R) sorption from a solution (vapor) by freshly formed crystals with production of substitution solid solutions under different types of self-disordering is studied. Changes of self-defectiveness and macrodefectiveness with time and effect of radiation defects in the presence of P macroquantities are taken into account. An analysis for monodispersed sorbents is performed. It is shown that the achievement of equilibrium within a reasonable time in impurity-solid phase system depends on defectiveness which ensures a required level of the coefficient of impurity diffusion in sorbent crystals.

Energy Technology Data Exchange (ETDEWEB)

Heat transfer has emerged as a leading-edge technology supporting the rapid pace of developments in science and engineering ranging from energy production to electronic cooling. Subjects covered at the 6th UK National Conference on heat transfer held at Edinburgh from 15-16 September 1999 include: convection; boiling and evaporation; condensation; numerical techniques; heat exchangers; radiation and combustion; conduction; two-phase flow and heat transfer augmentation. Fifteen of the papers are abstracted here.

Energy Technology Data Exchange (ETDEWEB)

Electron beam therapy applied to a lymph node metastasis from a squamous cell carcinoma was followed by the development of histologically and immunologically typical bullous pemphigoid, the lesions being initially strictly confined to the irradiation area. This observation suggests that the bullous pemphigoid antigen may be altered or unmasked by electron beam radiotherapy, leading subsequently to the production of autoantibodies. The disease in this case effectively responded to the administration of tetracycline and niacinamide, a therapeutic regimen described recently.

Energy Technology Data Exchange (ETDEWEB)

Food irradiation is the processing of food products by ionizing radiation in order, among other things, to control food borne pathogens, reduce microbial load and insect infestation, inhibit the germination of root crops, and extend the durable life of perishable products. Irradiation of dried food ingredients, particularly herbs and spices, has a great application potential, and has already been implemented in many countries. Spice irradiation is performed to increase the hygienic quality and used as decontamination processes instead of fumigation methods. European Community approves irradiation processing as an effective residue-free alternative. The present paper evaluates the effect of ionizing radiation on sensorial properties of cinnamon (Laurus cinnamomum) and nut meg (Myristica fragans). The samples have been irradiated in multipurpose irradiator of {sup 60}Co in the doses: 0, 5, 10, 15, 20 e 25 ...

Energy Technology Data Exchange (ETDEWEB)

In searching modulators of immunity and hematopoiesis among natural products, being used as foods, six herbs exhibited lymphocyte proliferation in vitro, and six exhibited augmentation of hematopoietic cell growth. The combined treatments showed synergistic effects of lymphocyte proliferation and of hematopoietic cell growth. On the other hand, we found four effective oriental medicinal prescriptions, used as energy tonic or blood-building decoctions, for survival and regeneration of hematopoietic cells and for protection of stem cells of intestinal crypt in irradiated mice. On the basis of these results, extracts from combinations of herbs were made in expectation of higher effects in the three respects. In immuno modulation activity by the two combinations of herbs was confirmed in mice. In culture of bone narrow cells, growth improvement of non-adherent precursor and induction of cytokine expression by herb mixture extracts were observed. In evaluation of ...

International Nuclear Information System (INIS)