Chemical species of iodine in some seaweeds. Pt. 2. Iodine-bound biological macromolecules

International Nuclear Information System (INIS)

Xiaolin Hou; Chifang Chai; Xiaojun Yan

2000-01-01

The distribution of iodine in various biological macromolecules in Sargassum kjellmanianum was studied using neutron activation analysis combined with chemical and biochemical separation techniques. The results indicate that iodine is mainly bound with protein, part of iodine with pigment and polyphenol, and little with polysaccharides, such as algin, fucoidan and cellulose. This result is significant for the mechanism of enriching iodine of algae and utilization of alga iodine. (author)

The I2 dissociation mechanisms in the chemical oxygen-iodine laser revisited.

Science.gov (United States)

Waichman, K; Barmashenko, B D; Rosenwaks, S

2012-06-28

The recently suggested mechanism of I(2) dissociation in the chemical oxygen-iodine laser (COIL) [K. Waichman, B. D. Barmashenko, and S. Rosenwaks, J. Appl. Phys. 106, 063108 (2009); and J. Chem. Phys. 133, 084301 (2010)] was largely based on the suggestion of V. N. Azyazov, S. Yu. Pichugin, and M. C. Heaven [J. Chem. Phys. 130, 104306 (2009)] that the vibrational population of O(2)(a) produced in the chemical generator is high enough to play an essential role in the dissociation. The results of model calculations based on this mechanism agreed very well with measurements of the small signal gain g, I(2) dissociation fraction F, and temperature T in the COIL. This mechanism is here revisited, following the recent experiments of M. V. Zagidullin [Quantum Electron. 40, 794 (2010)] where the observed low population of O(2)(b, v = 1) led to the conclusion that the vibrational population of O(2)(a) at the outlet of the generator is close to thermal equilibrium value. This value corresponds to a very small probability, ∼0.05, of O(2)(a) energy pooling to the states O(2)(X,a,b, v > 0). We show that the dissociation mechanism can reproduce the experimentally observed values of g, F, and T in the COIL only if most of the energy released in the processes of O(2)(a) energy pooling and O(2)(b) quenching by H(2)O ends up as vibrational energy of the products, O(2)(X,a,b), where the vibrational states v = 2 and 3 are significantly populated. We discuss possible reasons for the differences in the suggested vibrational population and explain how these differences can be reconciled.

Data acquisition and control system with a programmable logic controller (PLC) for a pulsed chemical oxygen-iodine laser

Science.gov (United States)

Yu, Haijun; Li, Guofu; Duo, Liping; Jin, Yuqi; Wang, Jian; Sang, Fengting; Kang, Yuanfu; Li, Liucheng; Wang, Yuanhu; Tang, Shukai; Yu, Hongliang

2015-02-01

A user-friendly data acquisition and control system (DACS) for a pulsed chemical oxygen -iodine laser (PCOIL) has been developed. It is implemented by an industrial control computer，a PLC, and a distributed input/output (I/O) module, as well as the valve and transmitter. The system is capable of handling 200 analogue/digital channels for performing various operations such as on-line acquisition, display, safety measures and control of various valves. These operations are controlled either by control switches configured on a PC while not running or by a pre-determined sequence or timings during the run. The system is capable of real-time acquisition and on-line estimation of important diagnostic parameters for optimization of a PCOIL. The DACS system has been programmed using software programmable logic controller (PLC). Using this DACS, more than 200 runs were given performed successfully.

Mechanism of singlet oxygen deactivation in an electric discharge oxygen – iodine laser

Energy Technology Data Exchange (ETDEWEB)

Azyazov, V N; Mikheyev, P A; Torbin, A P [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation); Pershin, A A [S.P. Korolev Samara State Aerospace University, Samara (Russian Federation); Heaven, M C [Emory University, Atlanta, GA, 30322 (United States)

2014-12-31

We have determined the influence of the reaction of molecular singlet oxygen with a vibrationally excited ozone molecule O{sub 2}(a {sup 1}Δ) + O{sub 3}(ν) → 2O{sub 2} + O on the removal rate of O{sub 2}(a {sup 1}Δ) in an electric-discharge-driven oxygen – iodine laser. This reaction has been shown to be a major channel of O{sub 2}(a {sup 1}Δ) loss at the output of an electric-discharge singlet oxygen generator. In addition, it can also contribute significantly to the loss of O{sub 2}(a {sup 1}Δ) in the discharge region of the generator. (lasers)

Adsorption of iodine from COIL waste gas on soaked coal-based activated carbon

Science.gov (United States)

Zhou, Junbo; Hao, Shan; Gao, Liping

2014-04-01

The chemical oxygen-iodine laser (COIL) has wide application prospects in military, industrial and medical treatment fields as a second generation gas chemical laser to follow the first HF/DF chemical laser. However, a COIL releases large amounts of gas, such as helium, oxygen, chlorine and iodine. Chlorides have a serious corrosive effect on the system, especially iodine vapor crystallization, which seriously endangers the normal use of vacuum systems, and radioactive methyl iodide, which is hazardous to operators and pollutes the environment. The use of soaked coal-based activated carbon as an adsorbent for removing methyl iodine is proposed, while it is proposed that coal-based activated carbon is an effective adsorbent for removing stable iodine. The research conducted in this work shows that iodine residues are less than 0.5 μg ml-1 after the adsorption treatment and the decontamination factor of the coal-based activated carbon for removing stable iodine is more than 1000. Using this method can achieve the purpose of removing harmful iodine, satisfy the requirements for engineering applications, and also be applied to other nuclear power plant flue gas treatments.

Changes is radioactive iodine metabolism in acute chemical intoxications

International Nuclear Information System (INIS)

Selyutitskij, G.V.; Likhtarev, I.A.; Volkova, N.V.; Zvonova, I.A.; Ostryakova, N.I.

1978-01-01

It is shown that the response of the endocrine system (iodine-absorbing and hormone-secreting fUnctions of the thyroid) as studied by the radioactive iodine test may be a reasonably versatile indicator of the response of the thyroid component of the endocrine system to acute intoxication of the organism. Trials of this test using seven chemical substances have confirmed that the radioiodine test is a sufficienty universal method to be used in setting sanitary and hygienic standards for permissible levels of chemical substances

Kinetics of an oxygen – iodine active medium with iodine atoms optically pumped on the {sup 2}P{sub 1/2} – {sup 2}P{sub 3/2} transition

Energy Technology Data Exchange (ETDEWEB)

Zagidullin, M V; Azyazov, V N [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation); Malyshev, M S [S.P. Korolev Samara State Aerospace University, Samara (Russian Federation)

2015-08-31

The kinetics of the processes occurring in an O{sub 2} – I{sub 2} – He – H{sub 2}O gas flow in which photodissociation of molecular iodine at a wavelength close to 500 nm and excitation of atomic iodine on the {sup 2}P{sub 1/2} – {sup 2}P{sub 3/2} transition by narrow-band radiation near 1315 nm are implemented successively has been analysed. It is shown that implementation of these processes allows one to form an oxygen – iodine medium with a high degree of dissociation of molecular iodine and a relative content of singlet oxygen O{sub 2}(a{sup 1}Δ) exceeding 10%. Having formed a supersonic gas flow with a temperature ∼100 K from this medium, one can reach a small-signal gain of about 10{sup -2} cm{sup -1} on the {sup 2}P{sub 1/2} – {sup 2}P{sub 3/2} transition in iodine atoms. The specific power per unit flow cross section in the oxygen – iodine laser with this active medium may reach ∼100 W cm{sup -2}. (active media)

Zero-valent iron pretreatment for detoxifying iodine in liquid crystal display (LCD) manufacturing wastewater

International Nuclear Information System (INIS)

Lee, J.W.; Cha, D.K.; Oh, Y.K.; Ko, K.B.; Song, J.S.

2009-01-01

This study investigated reductive transformation of iodine by zero-valent iron (ZVI), and the subsequent detoxification of iodine-laden wastewater. ZVI completely reduced aqueous iodine to non-toxic iodide. Respirometric bioassay illustrated that the presence of iodine increase the lag phase before the onset of oxygen consumption. The length of lag phase was proportional to increasing iodine dosage. The reduction products of iodine by ZVI did not exhibit any inhibitory effect on the biodegradation. The cumulative biological oxidation associated with iodine toxicity was closely fitted to Gompertz model. When iodine-laden wastewater was continuously fed to a bench-scale activated sludge unit, chemical oxygen demand (COD) removal efficiencies decreased from above 90% to below 80% along with a marked decrease in biomass concentration. On the other hand, the COD removal efficiency and biomass concentration remained constant in the integrated ZVI-activated sludge system. Respirometric bioassay with real iodine-laden LCD manufacturing wastewater demonstrated that ZVI was effective for detoxifying iodine and consequently enhancing biodegradability of wastewater. This result suggested that ZVI pretreatment may be a feasible option for the removal of iodine in LCD processing wastewater, instead of more costly processes such as adsorption and chemical oxidation, which are commonly in the iodine-laden LCD wastewater treatment facility

Radionuclide Basics: Iodine

Science.gov (United States)

... Centers Radiation Protection Contact Us Share Radionuclide Basics: Iodine Iodine (chemical symbol I) is a chemical element. ... in the environment Iodine sources Iodine and health Iodine in the Environment All 37 isotopes of iodine ...

Micro Chemical Oxygen-Iodine Laser (COIL)

National Research Council Canada - National Science Library

Livermore-Clifford, Carol

2007-01-01

.... The MEMS SOG contained an array of reaction channels for the chemical reaction of BHP and chlorine gas, a liquid-gas separator based on capillary effects, and integrated heat exchangers for thermal management...

Chemical thermodynamics of iodine species in the HTGR fuel particle

International Nuclear Information System (INIS)

Lindemer, T.B.

1982-09-01

The iodine-containing species in an intact fuel particle in the high-temperature gas-cooled reactor (HTGR) have been calculated. Assumptions include: (1) attainment of chemical thermodynamic equilibrium among all species in the open porosity of the particle, primarily in the buffer layer; and (2) fission-product concentrations in proportion to their yields. The primary gaseous species is calculated to be cesium iodide; in carbide-containing fuels, gaseous barium iodide may exhibit equivalent pressures. The condensed iodine-containing phase is usually cesium iodide, but in carbide-containing fuels, barium iodide may be stable instead. Absorption of elemental iodine on the carbon in the particle appears to be less than or equal to 10 -4 μg I/g C. The fission-product-spectra excess of cesium over iodine would generally be adsorbed on the carbon, but may form Cs 2 MoO 4 under some circumstances

Determination of chemical form of iodine with IC-ICP-MS system and its application to the environmental samples

International Nuclear Information System (INIS)

Yoshida, S.; Katou, S.; Sekimoto, H.; Muramatsu, Y.

2005-01-01

Iodine-129 is one of the important radionuclides possibly released into the environment from nuclear weapons testing and from the nuclear facilities such as nuclear fuel reprocessing plants. Because of its long half-life (1.57 x 10 7 y), knowing its long-term behavior in the environment is a major concern. As I-129 is expected to act together with stable iodine (I-127) in the environment after long time, the biogeochemical cycling of stable iodine in the environment can be used for the reliable safety assessment of I-129. Chemical form is the one of the important factors controlling the 'iodine behavior in the environment. Iodide (I - ) and iodate (IO 3 - ) are known to be the major chemical form in the aqueous solution. However, the information on the chemical form of iodine in the environmental sample is limited because of lack of reliable analytical technique for trace level of iodine in the environment. In this study, the analytical system by using ion chromatograph (IC) followed by inductively coupled plasma mass spectrometry (ICP-MS) was developed for the separate determination of I - and IO 3 - in the aqueous solution. The IC with anion exchange column (EXCELPAK ICS-A23) was used for the separation of I - and IO 3 - with 30 mM (NH 4 ) 2 CO 3 as eluent. Separated iodine was determined with ICP-MS on line. with the detection limit 0.1 - 1 μg/L. The total iodine concentration was also measured by the direct determination with ICP-MS. The iodine in the several environmental samples such as irrigation water in paddy field was successfully determined with information of chemical form. In incubation experiment with flooded soil, the change of the chemical form of iodine in the soil solution with change of Eh was observed. Detailed data will be discussed in the presentation.

Chemical behavior of gaseous iodine at very low concentrations

International Nuclear Information System (INIS)

Lin, C.C.; Wang, C.F.; Yang, M.H.

2000-01-01

This paper summarizes the major results obtained in a research project investigating the behavior of iodine aerosols. This project includes laboratory studies on radiation effects of iodine in the gas phase and the measurements of airborne radioiodine in nuclear facilities. It was found that under gamma irradiation, the iodide (I - ) ions in aerosol were readily oxidized to I 2 and HIO, and some iodide ions were converted to organic iodine when organic additive was presented in the KI solution from which the aerosol was generated. The results also indicate that the behavior of irradiated iodide aerosol depends on the chemistry environment in both the carrier gas and the iodide solution. The chemical forms of airborne radioiodine in an isotope production laboratory and a nuclear power plant effluent have also been measured. Although radioiodine has been observed in various forms, the activity in organic forms was found to be the dominating species in both cases. (author)

Oxidase catalysis via aerobically generated hypervalent iodine intermediates

Science.gov (United States)

Maity, Asim; Hyun, Sung-Min; Powers, David C.

2018-02-01

The development of sustainable oxidation chemistry demands strategies to harness O2 as a terminal oxidant. Oxidase catalysis, in which O2 serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O2 reduction. Direct O2 utilization suffers from intrinsic challenges imposed by the triplet ground state of O2 and the disparate electron inventories of four-electron O2 reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents—a broadly useful class of selective two-electron oxidants—from O2. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O2 reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.

Features of adsorbed chemical elements and their isotopes distribution in iodine air filters AU-1500 of nuclear power plant

International Nuclear Information System (INIS)

Neklyudov, I.M.; Dovbnya, A.N.; Dikiy, N.P.; Ledenyov, O.P.; Lyashko, Yu.V.

2013-01-01

The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The ?-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung gamma-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127 I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed.

Photochemistry of DNA containing iodinated cytosine

Energy Technology Data Exchange (ETDEWEB)

Rahn, R O; Stafford, R S [Oak Ridge National Lab., TN (USA)

1979-10-01

Irradiation at 313 nm of compounds containing iodinated cytosine moieties results in the photolysis of iodine. Photolysis occurs with a quantum yield of 0.022-0.024 for 5-iododeoxycytidine and 5-iododeoxycytidine monophosphate, and 0.004-0.008 for iodinated DNA as well as for iodinated polycytidylate. Photodegradation of the cytosine moiety occurs when air is present during irradiation, presumably due to the reaction of oxygen with the cytosyl radical formed when iodine is lost. This oxygen promoted photodegradation destroys the cytosine chromophore and is complete in the monomers but occurs to only a limited extent in the polymers. In the absence of oxygen or in the presence of ethanol, photodegradation is prevented and the loss of iodine leads exclusively to the formation of the cytosine chromophore. In DNA, the loss of iodine is accompanied by the formation of sugar damage and/or chain breaks. As measured by sedimentation in alkaline sucrose gradients, approximately one break is made for every six iodines lost in denatured DNA. The frequency of chain breakage per iodine photolyzed is reduced 2-fold in renatured DNA. Analysis in neutral gradients suggests that half of the breaks observed in alkali are alkali-labile bonds. Both ethanol and cysteamine reduce the number of chain breaks in alkali by approximately 3-fold.

Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

Science.gov (United States)

Krumhansl, James L; Nenoff, Tina M

2015-01-06

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

Mixed-layered bismuth-oxygen-iodine materials for capture and waste disposal of radioactive iodine

Science.gov (United States)

Krumhansl, James L; Nenoff, Tina M

2013-02-26

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

Selection of chemical forms of iodine for transmutation of 129I

International Nuclear Information System (INIS)

Shirasu, Yoshiro; Minato, Kazuo

2003-01-01

To select suitable chemical forms of iodine for the target for transmutation of 129 I, the properties of iodine compounds of NaI, MgI 2 , CaI 2 , CuI and Ca(IO 3 ) 2 were compared and the out-of-reactor heating experiments of the pellets of CuI and Ca(IO 3 ) 2 with the cladding materials were carried out. CuI and Ca(IO 3 ) 2 are not deliquescent but stable in the air, which is of great advantage to construction, operation and maintenance of the processing plants. The cladding with Cu metal liner could be compatible with CuI though the compatibility of the stainless steel with CuI is not good. Ca(IO 3 ) 2 should be deleted from the list of the candidate target materials for the transmutation of 129 I due to the severe chemical reaction with the cladding materials

Measurement of small-signal gain on COIL with chemically generated molecular iodine

Czech Academy of Sciences Publication Activity Database

Jirásek, Vít; Špalek, Otomar; Čenský, Miroslav; Kodymová, Jarmila

2010-01-01

Roč. 46, č. 9 (2010), s. 1350-1353 ISSN 0018-9197 Institutional research plan: CEZ:AV0Z10100523 Keywords : chemical lasers * iodine * gain measurement Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.477, year: 2010

Analysis of iodine chemical form noted from severe fuel damage experiments

International Nuclear Information System (INIS)

Cronenberg, A.W.; Osetek, D.J.

1986-01-01

Data from the TMI-2 accident has shown that only small amounts of iodine (I) escaped the plant. The postulated reason for such limited release is the formation of CsI (a salt) within fuel, which remains stable in a reducing high-temperature steam-H 2 environment. Upon cooldown CsI would dissolve in water condensate to form an ionic solution. However, recent data from fuel destruction experiments indicate different iodine release behavior that is tied to fuel burnup and oxidation conditions, as well as fission product concentration levels in the steam/H 2 effluent. Analysis of the data indicate that at low-burnup conditions, atomic I release from fuel is favored. Likewise, at low fission product concentration conditions HI is the favored chemical form in the steam/H 2 environment, not CsI. Results of thermochemical equilibria and chemical kinetics analysis support the data trends noted from the PBF-SFD tests. An a priori assumption of CsI for risk analysis of all accident sequences may therefore be inappropriate

Iodine generator for reclaimed water purification

Science.gov (United States)

Wynveen, R. A.; Powell, J. D.; Schubert, F. H. (Inventor)

1977-01-01

The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser.

Organic chemistry and radiochemistry: study of chemical interactions between iodine and paint of French nuclear reactor in a severe accident situation

International Nuclear Information System (INIS)

Aujollet, Y.

2005-01-01

In Phebus (French in pile facility; PWR scale 1/5000) experiments, performed by the Institut de Radioprotection et de Surete Nucleaire, few quantities of organic iodides were registered after interaction between iodine and reactor containment paint. This study concerns all mechanisms of chemical reactions between iodine and the polymer of the paint in order to estimate the organic iodides released from the paint. At first, all the paint components had been identified. Several models of chemical sites of the polymer were synthesized and tested with iodine in different conditions of temperature and radiation. These experiments showed interactions between iodine and secondary or tertiary amines by charge transfer. In few cases, the complex of tertiary amines creates oxidation reactions. (author)

The high-power iodine laser

Science.gov (United States)

Brederlow, G.; Fill, E.; Witte, K. J.

The book provides a description of the present state of the art concerning the iodine laser, giving particular attention to the design and operation of pulsed high-power iodine lasers. The basic features of the laser are examined, taking into account aspects of spontaneous emission lifetime, hyperfine structure, line broadening and line shifts, stimulated emission cross sections, the influence of magnetic fields, sublevel relaxation, the photodissociation of alkyl iodides, flashlamp technology, excitation in a direct discharge, chemical excitation, and questions regarding the chemical kinetics of the photodissociation iodine laser. The principles of high-power operation are considered along with aspects of beam quality and losses, the design and layout of an iodine laser system, the scalability and prospects of the iodine laser, and the design of the single-beam Asterix III laser.

Chemical identities of radioiodine released from U3O8 in oxygen and inert gas atmospheres

International Nuclear Information System (INIS)

Tachikawa, E.; Nakashima, M.

1977-01-01

Irradiated U 3 O 8 was heated from room temperature to 1100 0 C in a temperature-programmed oven (5 0 C/min) in a flow of carrier gas. The iodine released to an inert gas was deposited in the temperature range from 200 to 300 0 C with a peak at 250 0 C (speciesA). This species is neither in a form combined with other fission products nor in elemental form. It is possibly a chemical combination with uranium. It reacts with oxygen, yielding species B characterized by its deposition at a temperature close to room temperature. The activation energy of this oxidation reaction was determined to be 6.0 +-0.5 Kcal/mol. Comparing the deposition-profile with those obtained with carrier-free I 2 and HI indicated that species B was I 2 . As for the formation of organic iodides accompanying the release in an inert gas, it was concluded that these were produced in radical reactions. Thus, in a presence of oxygen, organic iodides were formed in competition with the reactions of organic radicals with oxygen. (author)

Iodine release from sodium pool combustion

International Nuclear Information System (INIS)

Sagawa, N.; Fukushima, Y.; Yokota, N.; Akagane, K.; Mochizuki, K.

1979-01-01

Iodine release associated with sodium pool combustion was determined by heating 20 gr sodium containing sodium iodide, which was labelled with 131 I and dissolved in the sodium in concentration of 1∼1,000 ppm, to burn on a nickel crucible in conditioned atmosphere in a closed vessel of 0.4 m 3 . Oxygen concentration was changed in 5∼21% and humidity in 0∼89% by mixing nitrogen gas and air. Combustion products were trapped by a Maypack filter composed of particle filters, copper screens and activated charcoal beds and by a glass beads pack cooled by liquid argon. Iodine collected on these filter elements was determined by radio-gas chromatography. When the sodium sample burned in the atmosphere of air at room temperature, the release fractions observed were 6∼33% for sodium and 1∼20% for iodine added in the sodium. The release iodine was present in aerosol at a ratio of 98%, and the remainder in the gas form. The release fraction of iodine trended to decrease as oxygen concentration and humidity in the atmosphere increased. No organic iodide was detected in the combustion products. (author)

Iodinated derivatives of vasoactive intestinal peptide (VIP), PHI and PHM: purification, chemical characterization and biological activity

International Nuclear Information System (INIS)

McMaster, D.; Suzuki, Y.; Rorstad, O.; Lederis, K.

1987-01-01

The iodination of vasoactive intestinal peptide (VIP) was studied, using a variety of enzymatic and chemical iodination methods. Reversed phase high performance liquid chromatography (HPLC) was used to purify the reaction products. The lactoperoxidase-glucose oxidase method gave excellent results in terms of reproducibility, iodine incorporation, and yield of the non-oxidized products [Tyr(I)10]VIP and [Tyr(I)22]VIP, and was used to prepare both 125 I and 127 I labelled derivatives. In both cases, direct application to HPLC and a single column system were used. Although the oxidized peptides [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP could be generated to varying degrees directly by iodination of VIP, these were most conveniently prepared by iodination of [Met(O)17]VIP. Iodinated derivatives of the homologous peptides PHI and PHM were likewise prepared by rapid, one-step HPLC procedures. The site and degree of iodination were determined by HPLC peptide mapping of tryptic digests and amino acid analyses, and in the case of [Tyr(I)10]VIP also by sequencing. The vasorelaxant activities of the iodinated peptides in bovine cerebral artery preparations did not differ significantly from those of the corresponding noniodinated peptides, with the exception of [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP which, unlike [Met(O)17]VIP itself, had slightly lower potency than VIP

Iodinated bleomycin

International Nuclear Information System (INIS)

Lunghi, F.; Riva, P.; Assone, F.; Villa, M.; Plassic, G.

1978-01-01

Bleomycin was labelled with iodine-131 by the iodine monochloride method. Iodination did not alter the chemical and chromatographic features and ''in vitro'' stability studies on freeze-dried 131 I-Bleomycin having a specific activity of 1 mCi/mg, stored at different temperatures, showed no appreciable variation of the free-iodine content. Tissue distribution of 131 I-Bleomycin has been evaluated in tumor bearing rats. Patients have been injected with 0.5-1.0 mCi of 131 I-Bleomycin corresponding to a maximum of 1.5 mg. No adverse reactions have been observed. Total body scans have been performed at 2, 6, 24 and 48 hours after injection. The iodinated Bleomycin was rapidly distributed and cleared from the body and showed an early uptake in the neoplastic tissue. A diagnostic accuracy of 90% has been observed in malignant deseases, while no false positive results have been, at the moment, recorded. (author)

Content iodine in sauces of type emulsion

Directory of Open Access Journals (Sweden)

M. Bakirov

2015-05-01

Full Text Available Introduction. The scarcity of natural resources arouse a necessity to find additional sources of protein, fat, carbohydrates, and their complexes with scarce mineral compounds. Therefore, a relevant issue is to enrich the diets deficient iodine compounds through research and development of new food products. Materials and methods. Investigation of iodine content in emulsion-type sauces at all stages was performed using Xray -fluorescence analyzer «Elvax». X-ray -fluorescence method consists of the appearance characteristic X-radiation of atoms of a chemical element at infringement they the primary X-ray irradiation. Results and discussion. Investigated for the determination of organic and inorganic forms of iodine in content of food items, and installed the total loss of iodine in sauces after cooking and storage at +5 ... +10 ° C for 30 days. Using iodine-proteinaceous additive from 0.5 ... 2.5% by mass of iodine 0.01% can be achieved from 15 to 50% of the human daily requirement by iodine. The resulting product does not lose its organoleptic, physico - chemical, consumer characteristics and meets the requirements of normative documents. As a result of our research, it was found that the addition of the supplements enriched protein-mineral (SEPM in composition sauces does not adversely affect the physical -chemical characteristics of sauces, but due to the stabilizing effect of additives iodine-proteinaceous increased emulsion stability up to 98 - 100% without additional foo d additives (emulsifiers. This additive has passed a series of tests that indicate on compliance with requirements normative and technical documentation. Conclusions. Used methodical approach allowed us to estimate the level of organic and inorganic iodine, as well as describe in more detail and correctly interpret the chemical composition of foods fortified with iodine and predict their health properties.

The iodine reactivity

International Nuclear Information System (INIS)

2003-01-01

The iodine is an important element because it has long life isotopes (such as iodine 129) and a great mobility in natural media. Iodine presents a complex chemistry because of its volatility and its strong redox reactivity. The S.E.C.R. works to better understand the reactivity of this element in different natural, industrial or biological environments. It plays a part in thermochemical sites as a possible way of hydrogen formation. This seminar gives some aspects relative to the chemical reactivity of iodine, since its thermochemistry in the I/S cycles to produce hydrogen to its reactivity in the natural medium and its potential radiological impact. This document includes 4 presentations transparencies) dealing with: the 129 I cycle rejected in the low radioactive gaseous and liquid effluents of the La Hague reprocessing plant (C. Frechou); a bibliographic review of iodine retention in soils (F. Bazer-Bachi); the hydrogen production and the iodine/sulfur thermochemical cycle (role of iodine in the process); and the direct characterization by electro-spray ionization mass spectroscopy of iodine fixation by fulvic acids (P. Reiller, B. Amekraz, C. Moulin, V. Moulin)

Modelling the chemistry of iodine

International Nuclear Information System (INIS)

Paquette, J.

1989-01-01

We have assembled a kinetic model, based on elementary chemical reactions, that describes the chemical behaviour of iodine in aqueous solution as a function of time and various parameters such as pH, concentration and radiation field. The model is conceptually divided into six section: aqueous iodine chemistry, aqueous organic iodide chemistry, water radiolysis, radiolysis of iodine solutions, radiolysis of organic iodide solutions and mass transfer. The model indicates that, in the absence of a radiation field, the rate of production of volatile iodine species is controlled by the rate of oxidation of the iodide ion. The volatile iodine species are dominated by organic iodides if organic impurities are present. The single most important parameter controlling iodine volatility is the pH of the solution; high pH values tend to minimize iodine volatility. In the presence of a radiation field, the volatility of iodine is controlled by the radiation-induced oxidation of the iodide ion. Again, iodine volatility is dominated by organic iodides if organic impurities are present. High pH values minimize iodine volatility. A sensitivity analysis has been performed on some sections of the model to identify reactions to which the volatility of iodine is most sensitive. In the absence of a radiation field, the volatility is most sensitive, first, to the rate of oxidation of the iodide ion, and, second, to the rate of mass transfer of volatile species between the aqueous and the gaseous phases. This approach should be useful in identifying reactions for which accurate rate constants are required and in decreasing the complexity of the model. 37 refs

Iodine oxides in large-scale THAI tests

International Nuclear Information System (INIS)

Funke, F.; Langrock, G.; Kanzleiter, T.; Poss, G.; Fischer, K.; Kühnel, A.; Weber, G.; Allelein, H.-J.

2012-01-01

Highlights: ► Iodine oxide particles were produced from gaseous iodine and ozone. ► Ozone replaced the effect of ionizing radiation in the large-scale THAI facility. ► The mean diameter of the iodine oxide particles was about 0.35 μm. ► Particle formation was faster than the chemical reaction between iodine and ozone. ► Deposition of iodine oxide particles was slow in the absence of other aerosols. - Abstract: The conversion of gaseous molecular iodine into iodine oxide aerosols has significant relevance in the understanding of the fission product iodine volatility in a LWR containment during severe accidents. In containment, the high radiation field caused by fission products released from the reactor core induces radiolytic oxidation into iodine oxides. To study the characteristics and the behaviour of iodine oxides in large scale, two THAI tests Iod-13 and Iod-14 were performed, simulating radiolytic oxidation of molecular iodine by reaction of iodine with ozone, with ozone injected from an ozone generator. The observed iodine oxides form submicron particles with mean volume-related diameters of about 0.35 μm and show low deposition rates in the THAI tests performed in the absence of other nuclear aerosols. Formation of iodine aerosols from gaseous precursors iodine and ozone is fast as compared to their chemical interaction. The current approach in empirical iodine containment behaviour models in severe accidents, including the radiolytic production of I 2 -oxidizing agents followed by the I 2 oxidation itself, is confirmed by these THAI tests.

Importance of chemical speciation of iodine in relation to dose estimates from 129I

International Nuclear Information System (INIS)

Sheppard, S.C.

1996-12-01

Biota live in a chemical milieu and take up elements according to laws of chemistry and physics. Radioactivity is not important to accumulation processes. However, for radionuclides it is almost always the radiological consequences that are important. As such, most discussions and modelling of the processes of distribution, exposure and consequences tend to deal with radionuclides and do not dwell on chemistry. In fact, the chemical aspects of dose estimation are dealt with quite adequately, but usually in an implicit rather than explicit manner. This report discusses the chemistry and chemical speciation of iodine (1) and illustrates how these topics have been implicitly included in biosphere models such as BIOTRAC, the model employed in the assessment of Canada's nuclear fuel waste disposal concept. Iodine is emphasized because 129 I is the dominant contributor to the hypothetical doses estimated. Not all aspects of the behaviour of 1 are implicit in BIOTRAC, but the exceptions are of minor importance. In general, the very broad ranges in parameter values specified for BIOTRAC encompass substantial latitude for the possible effects of chemical behaviour and speciation. Nonetheless, detailed understanding of the behavior of 1 in the environment is essential to the credibility of models such as BIOTRAC. There is substantial room for improved knowledge of the speciation of I, especially in freshwater and soil environments. (author)

Behavior of highly radioactive iodine on charcoal in moist air

International Nuclear Information System (INIS)

Lorenz, R.A.; Manning, S.R.; Martin, W.J.

1976-01-01

The behavior of highly radioactive iodine adsorbed on charcoal exposed to moist air (110 torr water vapor partial pressure) was investigated in a series of six experiments. The amount of radioactive 130 I on the well-insulated 28-cm 3 bed ranged from 50 to 570 Ci, and the relative humidity was 47 percent at the bed inlet temperature of 70 0 C. Radioactive iodine was released from the test beds at a continuous fractional release rate of approximately 7 x 10 -6 /hr for all types of charcoal tested. The chemical form of the released iodine was such that it was very highly penetrating with respect to the nine different types of commercial impregnated charcoals tested in backup collection beds. Two types of silver-nitrate-coated adsorption materials behaved similarly to the charcoals. Silver-exchanged type 13-X molecular sieve adsorbers were 20 to 50 times more efficient for adsorbing the highly penetrating iodine, but not as efficient as normally found for collecting methyl iodide. The chemical form of the highly penetrating iodine was not determined. When the moist air velocity was decreased from 28.5 fpm (25 0 C) to as low as 0.71 fpm (25 0 C), the charcoal bed temperature rose slowly and reached the ignition temperature in three of the experiments. At 0.71 fpm (25 0 C) the ignited charcoal beds reached maximum temperatures of 430 to 470 0 C because of the limited oxygen supply. The charcoal exposed for four years at Oak Ridge ignited at 283 0 C compared with 368 0 C for unused charcoal from the same batch. Two of the experiments used charcoal containing 1 or 2 percent TEDA (triethylene-diamine) and a proprietary flame retardant. The oxidation and ignition behavior of these charcoals did not appear to be affected adversely by the presence of the TEDA

Formation and behaviour of organic iodine

International Nuclear Information System (INIS)

Zilliacus, R.; Koukkar, P.; Karjunen, T.; Sjoevall, H.

2002-01-01

The report presents experimental studies on the formation of organic iodine in severe reactor accidents. The analyses were performed to evaluate the amount of alkaline chemical needed for effective pH control of containment water during the accidents. The formation of organic iodine in solutions used in the filtered venting system and the absorption of iodine compounds in the solutions were studied. Experiments for the formation of organic iodine on painted surfaces were also performed. (au)

Mechanism of Oxidative Amidation of Nitroalkanes with Oxygen and Amine Nucleophiles by Using Electrophilic Iodine.

Science.gov (United States)

Li, Jing; Lear, Martin J; Kwon, Eunsang; Hayashi, Yujiro

2016-04-11

Recently, we developed a direct method to oxidatively convert primary nitroalkanes into amides that entailed mixing an iodonium source with an amine, base, and oxygen. Herein, we systematically investigated the mechanism and likely intermediates of such methods. We conclude that an amine-iodonium complex first forms through N-halogen bonding. This complex reacts with aci-nitronates to give both α-iodo- and α,α-diiodonitroalkanes, which can act as alternative sources of electrophilic iodine and also generate an extra equimolar amount of I(+) under O2. In particular, evidence supports α,α-diiodonitroalkane intermediates reacting with molecular oxygen to form a peroxy adduct; alternatively, these tetrahedral intermediates rearrange anaerobically to form a cleavable nitrite ester. In either case, activated esters are proposed to form that eventually reacts with nucleophilic amines in a traditional fashion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxygen-hydrogen fuel cell with an iodine-iodide cathode - A concept

Science.gov (United States)

Javet, P.

1970-01-01

Fuel cell uses a porous cathode through which is fed a solution of iodine in aqueous iodide solution, the anode is a hydrogen electrode. No activation polarization appears on the cathode because of the high exchange-current density of the iodine-iodide electrode.

Chemical treatment of wastewaters produced during separation of iodine 131

International Nuclear Information System (INIS)

Cohen, P.; Marcaillou, J.; Amavis, R.

1959-01-01

The authors report the development and assessment of a chemical treatment of radioactive wastewaters by co-precipitation. This treatment is aimed at replacing a treatment based on the use of calcium phosphate which proved to be insufficient for wastewaters resulting from the production of iodine 131. After a presentation of the characteristics of the effluents to be processed, the authors report co-precipitation tests performed on effluents before release in the storage vessel (by using barium hydroxide, lead acetate or lead sulfate) and on effluents diluted on the storage vessel. They show that a co-precipitation method based on the use of lead sulfate in alkaline medium gives the best results

Iodine in the environment revisited

International Nuclear Information System (INIS)

Christiansen, J.V.; Carlsen, L.

1989-05-01

The report gives an overview of the environmental cycle of iodine, especially focusing on the possible reactions being responsible for the retention of iodine in the terrestrial environment. During the last two decades evidence for the presence of iodine in soil as organically bound has been presented. The major part of inorganic iodine in the terrestrial environment will, under physical and chemical conditions normally prevailing, exist as iodide. No evidence for a direct reaction between iodide and organic material has been presented, whereas strong support for the engagement of microbial activity in the formation of organic iodine compounds in soil has been obtained. Incorporation of iodine in humic substances as a result of enzymatic catalysis, involving an enzyme of the perozidase group apperas reasonable. It is concluded that microbiological activity involving extracellular enzymes most probably is responsible for the possible retention of iodine in the terrestrial environment. It is suggested that these reactions in detail should be studied experimentally. (author) 3 tabs., 2 ills., 51 refs

Uncertainty of inhalation dose coefficients for representative physical and chemical forms of iodine-131

Science.gov (United States)

Harvey, Richard Paul, III

Releases of radioactive material have occurred at various Department of Energy (DOE) weapons facilities and facilities associated with the nuclear fuel cycle in the generation of electricity. Many different radionuclides have been released to the environment with resulting exposure of the population to these various sources of radioactivity. Radioiodine has been released from a number of these facilities and is a potential public health concern due to its physical and biological characteristics. Iodine exists as various isotopes, but our focus is on 131I due to its relatively long half-life, its prevalence in atmospheric releases and its contribution to offsite dose. The assumption of physical and chemical form is speculated to have a profound impact on the deposition of radioactive material within the respiratory tract. In the case of iodine, it has been shown that more than one type of physical and chemical form may be released to, or exist in, the environment; iodine can exist as a particle or as a gas. The gaseous species can be further segregated based on chemical form: elemental, inorganic, and organic iodides. Chemical compounds in each class are assumed to behave similarly with respect to biochemistry. Studies at Oak Ridge National Laboratories have demonstrated that 131I is released as a particulate, as well as in elemental, inorganic and organic chemical form. The internal dose estimate from 131I may be very different depending on the effect that chemical form has on fractional deposition, gas uptake, and clearance in the respiratory tract. There are many sources of uncertainty in the estimation of environmental dose including source term, airborne transport of radionuclides, and internal dosimetry. Knowledge of uncertainty in internal dosimetry is essential for estimating dose to members of the public and for determining total uncertainty in dose estimation. Important calculational steps in any lung model is regional estimation of deposition fractions

Evaluation method of iodine re-evolution from an in-containment water pool after a loss of coolant accident, Part II: Evaluation of pH and iodine re-evolution

International Nuclear Information System (INIS)

Kim, Tae Hyeon; Jeong, Ji Hwan

2016-01-01

Highlights: • It is required to evaluate re-evolved iodine from sump water after LOCA. • Transport of iodine and chemicals influencing pH were analyzed using CFD. • Chemical conditions of the iodine-rich region suppress iodine re-evolution. • The current evaluation method for I 2 re-evolution is excessively conservative. - Abstract: Radioactive iodine that is released during a postulated loss of coolant accident is dissolved into the containment spray water and transported into the in-containment refueling water storage tank (IRWST). The re-evolution of iodine from the water is a safety concern. In this study, three-dimensional computational fluid dynamics (CFD) analyses are conducted in order to analyze the transport of chemical species including iodine in the IRWST and to calculate the amount of iodine that re-evolves from the IRWST water. The CFD analyses demonstrate that the pH of water is high where the iodine concentration is high. Considering that the creation rate of molecular iodine declines as the pH increases, it can be understood that the iodine re-evolution is not so strong in practical situations because the chemical conditions of the iodine-rich region suppress the re-evolution of the iodine. In addition, four different methods for evaluating the amount of re-evolved iodine are examined. The amount of re-evolved iodine calculated using the total-volume-average values, which are currently used for safety analyses, appear to be significantly higher than those determined using other methods. The amount of re-evolved iodine estimated using a realistic method with a conservative assumption of volatilization appears to be approximately one thousandth of that evaluated using the current method. This implies that the current method is very conservative.

Tri-metallic ferrite oxygen carriers for chemical looping combustion

Science.gov (United States)

Siriwardane, Ranjani V.; Fan, Yueying

2017-10-25

The disclosure provides a tri-metallic ferrite oxygen carrier for the chemical looping combustion of carbonaceous fuels. The tri-metallic ferrite oxygen carrier comprises Cu.sub.xFe.sub.yMn.sub.zO.sub.4-.delta., where Cu.sub.xFe.sub.yMn.sub.zO.sub.4-.delta. is a chemical composition. Generally, 0.5.ltoreq.x.ltoreq.2.0, 0.2.ltoreq.y.ltoreq.2.5, and 0.2.ltoreq.z.ltoreq.2.5, and in some embodiments, 0.8.ltoreq.x.ltoreq.1.2, y.ltoreq.1.2, and z.gtoreq.0.8. The tri-metallic ferrite oxygen carrier may be used in various applications for the combustion of carbonaceous fuels, including as an oxygen carrier for chemical looping combustion.

Radiolytical oxidation of gaseous iodine by beta radiation

International Nuclear Information System (INIS)

Kaerkelae, Teemu; Auvinen, Ari; Kekki, Tommi; Kotiluoto, Petri; Lyyraenen, Jussi; Jokiniemi, Jorma

2015-01-01

Iodine is one of the most radiotoxic fission product released from fuel during a severe nuclear power plant accident. Within the containment building, iodine compounds can react e.g. on the painted surfaces and form gaseous organic iodides. In this study, it was found out that gaseous methyl iodide (CH 3 I) is oxidised when exposed to beta radiation in an oxygen containing atmosphere. As a result, nucleation of aerosol particles takes place and the formation of iodine oxide particles is suggested. These particles are highly hygroscopic. They take up water from the air humidity and iodine oxides dissolve within the droplets. In order to mitigate the possible source term, it is of interest to understand the effect of beta radiation on the speciation of iodine.

Radiolytical oxidation of gaseous iodine by beta radiation

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, Teemu; Auvinen, Ari; Kekki, Tommi; Kotiluoto, Petri; Lyyraenen, Jussi [VTT Technical Research Centre of Finland, Espoo (Finland); Jokiniemi, Jorma [VTT Technical Research Centre of Finland, Espoo (Finland); Eastern Finland Univ., Kuopio (Finland)

2015-07-01

Iodine is one of the most radiotoxic fission product released from fuel during a severe nuclear power plant accident. Within the containment building, iodine compounds can react e.g. on the painted surfaces and form gaseous organic iodides. In this study, it was found out that gaseous methyl iodide (CH{sub 3}I) is oxidised when exposed to beta radiation in an oxygen containing atmosphere. As a result, nucleation of aerosol particles takes place and the formation of iodine oxide particles is suggested. These particles are highly hygroscopic. They take up water from the air humidity and iodine oxides dissolve within the droplets. In order to mitigate the possible source term, it is of interest to understand the effect of beta radiation on the speciation of iodine.

Semiconducting Properties of Nanostructured Amorphous Carbon Thin Films Incorporated with Iodine by Thermal Chemical Vapor Deposition

Science.gov (United States)

Kamaruzaman, Dayana; Ahmad, Nurfadzilah; Annuar, Ishak; Rusop, Mohamad

2013-11-01

Nanostructured iodine-post doped amorphous carbon (a-C:I) thin films were prepared from camphor oil using a thermal chemical vapor deposition (TCVD) technique at different doping temperatures. The structural properties of the films were studied by field-emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Raman, and Fourier transform infrared (FTIR) studies. FESEM and EDS studies showed successful iodine doping. FTIR and Raman studies showed that the a-C:I thin films consisted of a mixture of sp2- and sp3-bonded carbon atoms. The optical and electrical properties of a-C:I thin films were determined by UV-vis-NIR spectroscopy and current-voltage (I-V) measurement respectively. The optical band gap of a-C thin films decreased upon iodine doping. The highest electrical conductivity was found at 400 °C doping. Heterojunctions are confirmed by rectifying the I-V characteristics of an a-C:I/n-Si junction.

Further assessment of the chemical modelling of iodine in IMPAIR 3 code using ACE/RTF data

International Nuclear Information System (INIS)

Cripps, R.C.; Guentay, S.

1996-01-01

This paper introduces the assessment of the computer code IMPAIR 3 (Iodine Matter Partitioning And Iodine Release) which simulates physical and chemical iodine processes in a LWR containment with one or more compartments under conditions relevant to a severe accident in a nuclear reactor. The first version was published in 1992 to replace both the multi-compartment code IMPAIR 2/M and the single-compartment code IMPAIR 2.2. IMPAIR 2.2 was restricted to a single pH value specified before programme execution and precluded any variation of pH or calculation of H + changes during program execution. This restriction is removed in IMPAIR 3. Results of the IMPAIR 2.2 assessment using ACE/RTF Test 2 and the acidic phase of Test 3 B data were presented at the 3rd CSNI Workshop. The purpose of the current assessment is to verify the IMPAIR 3 capability to follow the whole test duration with changing boundary conditions. Besides revisiting ACE/RTF Test 3B, Test 4 data were also used for the current assessment. A limited data analysis was conducted using the outcome of the current ACEX iodine work to understand the iodine behaviour observed during these tests. This paper presents comparisons of the predicted results with the test data. The code capabilities are demonstrated to focus on still unresolved modelling problems. The unclear behaviour observed in the gaseous molecular iodine behaviour and its inconclusive effect on the calculated behaviour in the acidic phase of the Test 4 and importance of the catalytic effect of stainless steel are also indicated. (author) 18 figs., 1 tab., 11 refs

Further assessment of the chemical modelling of iodine in IMPAIR 3 code using ACE/RTF data

Energy Technology Data Exchange (ETDEWEB)

Cripps, R C; Guentay, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1996-12-01

This paper introduces the assessment of the computer code IMPAIR 3 (Iodine Matter Partitioning And Iodine Release) which simulates physical and chemical iodine processes in a LWR containment with one or more compartments under conditions relevant to a severe accident in a nuclear reactor. The first version was published in 1992 to replace both the multi-compartment code IMPAIR 2/M and the single-compartment code IMPAIR 2.2. IMPAIR 2.2 was restricted to a single pH value specified before programme execution and precluded any variation of pH or calculation of H{sup +} changes during program execution. This restriction is removed in IMPAIR 3. Results of the IMPAIR 2.2 assessment using ACE/RTF Test 2 and the acidic phase of Test 3 B data were presented at the 3rd CSNI Workshop. The purpose of the current assessment is to verify the IMPAIR 3 capability to follow the whole test duration with changing boundary conditions. Besides revisiting ACE/RTF Test 3B, Test 4 data were also used for the current assessment. A limited data analysis was conducted using the outcome of the current ACEX iodine work to understand the iodine behaviour observed during these tests. This paper presents comparisons of the predicted results with the test data. The code capabilities are demonstrated to focus on still unresolved modelling problems. The unclear behaviour observed in the gaseous molecular iodine behaviour and its inconclusive effect on the calculated behaviour in the acidic phase of the Test 4 and importance of the catalytic effect of stainless steel are also indicated. (author) 18 figs., 1 tab., 11 refs.

Iodine-129 separation and determination by neutron activation analysis

International Nuclear Information System (INIS)

Bate, L.C.; Stokely, J.R.

1982-01-01

This paper describes a method for analysis of iodine-129 in fission product mixtures originating from fuel reprocessing studies and low-level wastes. The method utilizes conventional iodine valence adjustment and solvent extraction techniques to chemically separate iodine-129 from most fission products. The iodine-129 is determined by neutron irradiation and measurement of the 12.4 hour iodine-130 produced by the neutron capture reaction. Special techniques were devised for neutron irradiation of iodine-129 samples in the pneumatic tube irradiation facilities at the High Flux Isotope (HFIR) and Oak Ridge Research (ORR) Reactors. Chemically separated iodine-129 is adsorbed on an anion exchange resin column made from an irradiation container. The loaded resin is then irradiated in either of the pneumatic facilities to produce iodine-130. Sensitivity of the analysis with the HFIR facility (flux: 5x10 14 n/cm 2 /s) and a 100 second irradiation time is approximately 0.03 nanograms. Samples up to 250 ml in volume can be easily processed. (author)

Atomic iodine production in a gas flow by decomposing methyl iodide in a dc glow discharge

International Nuclear Information System (INIS)

Mikheyev, P A; Shepelenko, A A; Voronov, A I; Kupryaev, Nikolai V

2002-01-01

The production of atomic iodine for an oxygen - iodine laser is studied by decomposing methyl iodide in a dc glow discharge in a vortex gas flow. The concentration of iodine atoms in discharge products was measured from the atomic iodine absorption of the radiation of a single-frequency tunable diode laser at a wavelength of 1.315 μm. Atomic iodine concentrations sufficient for the operation of an oxygen - iodine laser were obtained. The concentration of atomic iodine amounted to 3.6 x 10 15 cm -3 for a pressure of the carrying argon gas of 15 Torr. The discharge stabilisation by a vortex gas flow allowed the glow discharge to be sustained in a strongly electronegative halogen-containing gas mixture for pressures up to 20 Torr. (active media)

Abiotic production of iodine molecules in irradiated ice

Science.gov (United States)

Choi, Wonyong; Kim, Kitae; Yabushita, Akihiro

2015-04-01

Reactive halogen species play an important role in Earth's environmental systems. Iodine compounds are related to ozone depletion event (ODE) during Antarctic spring, formation of CCN (cloud condensation nuclei), and controlling the atmospheric oxidizing capacity. However, the processes and mechanisms for abiotic formation of iodine compounds in polar region are still unclear. Although the chemical reactions taking place in ice are greatly different from those in aquatic environment, reaction processes of halogens in frozen condition have rarely studied compared to those in water. In this study, we investigated iodide oxidation to form triiodide (I3-) in ice phase under UV irradiation ( λ > 300 nm) and dark condition. The production of I3- through iodide oxidation, which is negligible in aqueous solution, was significantly accelerated in ice phase even in the absence of UV irradiation. The following release of gaseous iodine molecule (I2) to the atmosphere was also monitored by cavity ring-down spectroscopy (CRDS). We speculate that the markedly enhanced iodide oxidation in polycrystalline ice is due to the freeze concentration of iodides, protons, and dissolved oxygen in the ice crystal grain boundaries. The experiments conducted under ambient solar radiation of the Antarctic region (King George Island, 62°13'S 58°47'W, sea level) also confirmed that the generation of I3- via iodide oxidation process is enhanced when iodide is trapped in ice. The observed intrinsic oxidative transformation of iodide to generate I3-(aq) and I2(g) in frozen environment suggests a previously unknown pathway for the substantial release of reactive iodine species to the atmosphere.

Iodine isotopes and radiation safety

International Nuclear Information System (INIS)

Styro, B.; Nedvekajte, T.; Filistovich, V.

1992-01-01

Methods of concentration determination of stable and radioactive iodine isotopes in the Earth's different geospheres are described. Iodine isotopes concentration data, chemical forms and transformations as well as their exchange among separate geospheres of their global biochemical circulation (ocean, atmosphere, lithosphere and biosphere) are presented. Information on iodine isotopes as after-effects of nuclear installations accident (in particular, the Chernobyl accident) is generalized. The book is intended for scientists and practical workers in ecology and radioactivity protection and for a students of physics. 442 refs.; 82 figs.; 36 tabs

Iodine and microbial interactions in an organic soil

International Nuclear Information System (INIS)

Sheppard, M.I.; Hawkins, J.L.

1995-01-01

Iodine-129 in groundwater discharging from a geological disposal vault could accumulate in wetlands by chemical sorption onto low pH, highly organic solid surfaces or by direct or indirect microbial processes. Previous work indicated that saturation of anion sorption sites, microbial toxicity, or swamping of the I reduction/oxidation reaction decreased the retention of a wetland sphagnum for iodine with increased iodine porewater concentrations. Bog water and peat of an iodine-rich bog were studied to elucidate the role of micro-organisms in the retention and accumulation of iodine in a temperate wetland. (author)

Iodine-Catalyzed Isomerization of Dimethyl Muconate

Energy Technology Data Exchange (ETDEWEB)

Settle, Amy E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berstis, Laura R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Shuting [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hu, Haiming [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Ryan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-12

cis,cis-Muconic acid is a platform biobased chemical that can be upgraded to drop-in commodity and novel monomers. Among the possible drop-in products, dimethyl terephthalate can be synthesized via esterification, isomerization, Diels-Alder cycloaddition, and dehydrogenation. The isomerization of cis,cis-dimethyl muconate (ccDMM) to the trans,trans-form (ttDMM) can be catalyzed by iodine; however, studies have yet to address (i) the mechanism and reaction barriers unique to DMM, and (ii) the influence of solvent, potential for catalyst recycle, and recovery of high-purity ttDMM. To address this gap, we apply a joint computational and experimental approach to investigate iodine-catalyzed isomerization of DMM. Density functional theory calculations identified unique regiochemical considerations due to the large number of halogen-diene coordination schemes. Both transition state theory and experiments estimate significant barrier reductions with photodissociated iodine. Solvent selection was critical for rapid kinetics, likely due to solvent complexation with iodine. Under select conditions, ttDMM yields of 95% were achieved in <1 h with methanol, followed by high purity recovery (>98%) with crystallization. Lastly, post-reaction iodine can be recovered and recycled with minimal loss of activity. Overall, these findings provide new insight into the mechanism and conditions necessary for DMM isomerization with iodine to advance the state-of-the-art for biobased chemicals.

Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture.

Science.gov (United States)

Voogt, Wim; Holwerda, Harmen T; Khodabaks, Rashied

2010-04-15

Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 microg iodine L(-1), applied as iodate (IO(3)(-)) or iodide (I(-)), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I(-) than with IO(3)(-). Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 microg iodine kg(-1) total leaf fresh weight. Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I(-) and IO(3)(-). I(-) was more effective than IO(3)(-). Fifty grams of iodine-biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. (c) 2010 Society of Chemical Industry.

Chemical oxygen demand (cod) attenuation of methyl red in water ...

African Journals Online (AJOL)

Chemical oxygen demand (cod) attenuation of methyl red in water using biocarbons obtained from Nipa palm leaves. ... eco-friendly and locally accessible biocarbon for mitigation of organic contaminants in water. Keywords: Chemical oxygen demand, biocarbon, methyl red, biodegradation, bioremediation, Nipa palm ...

Oxygen Chemical Diffusion Coefficients of (Pu,Am)O2 Fuels

International Nuclear Information System (INIS)

Watanabe, M.; Kato, M.; Matsumoto, T.

2015-01-01

Minor actinide (MA)-bearing MOX fuels have been developed as candidate fuels which are used in fast neutron spectrum cores such as sodium-cooled fast reactor (SFR) cores and experimental accelerator driven system (ADS) cores. Americium (Am) which is one of the MA elements significantly affects basic properties. It is known that Am content causes oxygen potential to increase and that influences irradiation behaviour such as fuel-cladding chemical interaction (FCCI) and chemical state of fission products. However, the effects of Am content on changes of basic properties are not clear. In this work, the oxygen chemical diffusion coefficients were calculated from measured data and the relationship between oxygen diffusion and oxygen potential of (Pu,Am)O 2-x was discussed. (authors)

Immobilization and bonding scheme of radioactive iodine-129 in silver tellurite glass

Science.gov (United States)

Lee, Cheong Won; Pyo, Jae-Young; Park, Hwan-Seo; Yang, Jae Hwan; Heo, Jong

2017-08-01

Silver tellurite glasses with melting temperatures disposal site. Iodine waste loading in glasses was as high as 12.64 wt% of all metallic elements and 11.21 wt% including oxygen. Normalized elemental releases obtained from the product consistency test were well below US regulation of 2 g/m2. Iodines are surrounded by four Ag+ ions forming [Ag4I]3+ units that are further connected to tellurite network through bonds with non-bridging oxygens.

The effect of hydrostatic pressure on conductivity behaviour of needle crystals of iodine and oxygen doped niobium-sulphur compounds

International Nuclear Information System (INIS)

Balla, D.D.; Bondarenko, A.V.; Obolenskij, M.A.; Beletskij, V.I.; Chashka, Kh.B.

1985-01-01

The effect of the hydrostatic pressures up to 11 kbar on conductivity behaviour of the needle crystal of iodine and oxygen doped niobium-sulphur compounds were studied in the temperature range 4.2-300 K. It is shown that in the temperature range 110-300 K conductivity is thermal activated (P=1 bar). Below 110 K the Mott characteristic is observed. Under hydrostatic pressure the deviations from Mott characteristic occurs. The analysis of data suggested that crystals are doped semiconductors

Simulation of ISTP-EPICUR Iodine Chemistry Tests with RAIM

Energy Technology Data Exchange (ETDEWEB)

Kim, Han-Chul; Cho, Yeong-Hun; Jang, Dong-Ju; Ryu, Myung-Hyun [Nuclear Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2014-10-15

The amount of iodine release largely depends on its volatility in the containment. Iodine has several chemical forms including aerosols, vapor, and gas. Among them gaseous iodine such as I{sub 2} and organic iodide are dominating due to their high volatility. Therefore, such iodine behavior has been extensively examined. Korea Institute of Nuclear Safety (KINS) has been joining the relevant international programs such as ISTP-EPICUR, OECD-BIP and OECD-STEM. In the course of this study, a simple iodine model, RAIM (Radio-Active Iodine chemistry Model) has been developed, based on the IMOD methodology and other previous studies. This model deals with chemical reactions associated with formation and destruction of iodine species in the containment atmosphere and the sump in a simple manner, as shown in Fig. 1. It also treats adsorption and desorption of volatile iodine on the paint surface. The iodine species modeled are inorganic volatile iodine, organic iodides of high volatility (HVRI) and low volatility (LVRI), non-volatiles, non-aqueous iodine, and iodine oxide aerosols (IO{sub x}). Many other material participating in the iodine reactions, e.g., air radiolysis products (ARP) such as ozone, are also modeled. This paper especially shows the analysis results after addition of gaseous reaction model to RAIM, which was further accompanied by adjustments of the existing reaction rate constants even for the aqueous reactions. After integration of iodine reaction models for gas and aqueous phase, RAIM was applied the S1-9 and S1-11 tests which were carried out in aqueous phase. In addition, re-analysis of the S2-6-5-2 test, for which iodine-loaded coupons were tested in gas phase, was also performed.

Effects of chemical kinetics and starting material regeneration on the efficiency of an iodine laser amplifier

International Nuclear Information System (INIS)

Fisk, G.A.

1977-05-01

A model of the chemical kinetics occurring in an iodine laser amplifier is presented and used to calculate the degree to which the starting material is consumed as a result of laser operation. The cost of purchasing new starting material is estimated and shown to be prohibitive. A scheme for regenerating the starting material from the species present in the amplifier after lasing is proposed. It is shown that the estimated efficiency of this chemical regeneration process is appreciably higher than the projected optimum efficiency of the pumping process

The behaviour of iodine in the terrestrial environment

International Nuclear Information System (INIS)

Christiansen, J.V.

1990-02-01

Literature on the geochemistry of iodine is surveyed, focusing on fundamental chemical aspects which influence the migration behaviour of iodine in the terrestrial environment. It is stated that the organic fraction in soil plays the predominant role in the retention of iodine. Simple aromatic molecules serve as simple models for humic acid, and humic acid is iodinated catalyzed by haloperoxidases. The enzymatically controlled iodination of humic acid is described in detail and it is demonstrated that the results may reflect a kind of equilibrium. It is shown that soil extracts are able to catalyze the iodination of humic acid and it is suggested that extracellular peroxidases in soil are reponsible for the reaction. The enzymatically controlled iodination of humic acid is discussed and some considerations about the influence on the migration of iodine in the terrestrial environment are given. (author) 4 tabs., 26 ills., 82 refs

Determination of iodine at ppt level in a nitric acid medium by inductively coupled plasma sector field mass spectrometry: influence of the chemical forms

International Nuclear Information System (INIS)

Langlois, B.

2001-01-01

Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP/SFMS) was used to determine several chemical forms of iodine, at ppt level, in a nitric acid media. Ascorbic acid was added as a reducing agent in order to maintain iodine as iodide. In a preliminary approach, the influence of the chemical form was studied by comparing inorganic iodine (NaI) and organic iodine (CH3I). Different signal responses were observed. With a conventional sample introduction system, sensitivities obtained for iodo-methane could differ by a factor of 5. This was not caused by a problem of atomization or by a change in the ionization efficiency of the iodo-compound into the plasma. The low volatilization temperature of iodo-methane (315.5 K) seemed to be the main explanation of this phenomena. Actually, nebulization resulted in the volatilization of a 2% nitric acid solution containing iodo-methane. As a result, the transport efficiency of iodo-methane between the nebulizer and the torch was approaching 100%. A Direct Injection High Efficiency Nebulizer (DIHEN) allowed us to minimize the behavior difference between the two iodine species, but the sensitivity ratio was inverted and still differed by 20 - 40%. Moreover, the association of a guard electrode and the direct injection system was studied in order to apply these equipments to the determination of iodine. This association allowed us to improve the sensitivity by a factor of 10 and to minimize memory effects, when compared with a conventional system. Further studies indicated that signal responses obtained with different iodine-containing species, except for iodo-methane, were found to be similar. (author)

Estimation of iodine in soils by neutron activation analysis

International Nuclear Information System (INIS)

Krishnamoorthy, K.R.; Iyer, R.K.

1982-01-01

This paper reports the determination of the iodine content of soils by neutron activation analysis. The irradiated sample is fused with alkali in presence of 131 I tracer. From the aqueous extract, iodine activity is extracted into carbon tetrachloride and stripped back to aqueous phase with a high selectivity for iodine. 131 I tracer is used to measure chemical yield. Iodine contents in the range 1 to 20 ppm. have been determined by this technique. (author)

Chemical-Looping Combustion and Gasification of Coals and Oxygen Carrier Development: A Brief Review

Directory of Open Access Journals (Sweden)

Ping Wang

2015-09-01

Full Text Available Chemical-looping technology is one of the promising CO2 capture technologies. It generates a CO2 enriched flue gas, which will greatly benefit CO2 capture, utilization or sequestration. Both chemical-looping combustion (CLC and chemical-looping gasification (CLG have the potential to be used to generate power, chemicals, and liquid fuels. Chemical-looping is an oxygen transporting process using oxygen carriers. Recently, attention has focused on solid fuels such as coal. Coal chemical-looping reactions are more complicated than gaseous fuels due to coal properties (like mineral matter and the complex reaction pathways involving solid fuels. The mineral matter/ash and sulfur in coal may affect the activity of oxygen carriers. Oxygen carriers are the key issue in chemical-looping processes. Thermogravimetric analysis (TGA has been widely used for the development of oxygen carriers (e.g., oxide reactivity. Two proposed processes for the CLC of solid fuels are in-situ Gasification Chemical-Looping Combustion (iG-CLC and Chemical-Looping with Oxygen Uncoupling (CLOU. The objectives of this review are to discuss various chemical-looping processes with coal, summarize TGA applications in oxygen carrier development, and outline the major challenges associated with coal chemical-looping in iG-CLC and CLOU.

Characterization of iodinated adrenomedullin derivatives suitable for lung nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Fu Yan; Letourneau, Myriam; Chatenet, David [Laboratoire d' etudes moleculaires et pharmacologiques des peptides, INRS-Institut Armand-Frappier, Ville de Laval, Qc, H7V 1B7 (Canada); Dupuis, Jocelyn [Research Center, Montreal Heart Institute, Montreal, Qc (Canada); Department of Medicine, University of Montreal, Montreal, Qc (Canada); Fournier, Alain, E-mail: alain.fournier@iaf.inrs.ca [Laboratoire d' etudes moleculaires et pharmacologiques des peptides, INRS-Institut Armand-Frappier, Ville de Laval, Qc, H7V 1B7 (Canada)

2011-08-15

Introduction: We have recently demonstrated the effectiveness of 99m-technetium adrenomedullin (AM) as a new molecular lung imaging agent that could provide significant advantages for the diagnosis and follow-up of disorders affecting the pulmonary circulation such as pulmonary embolism and pulmonary hypertension. Having the possibility to conjugate the targeting molecule with different radionuclides would offer more flexibility and potential advantages depending on clinical situations. Since various iodine isotopes are currently used in nuclear medicine and in pharmacological studies, we have evaluated which iodination method should be privileged in order to produce a good iodinated AM-derived nuclear medicine agent. Methods: Synthetic AM was labeled with iodine through chemical and lactoperoxidase oxidation methods. Position of the iodine atom on the peptide was determined by MALDI-TOF mass spectrometry analysis following cyanogen bromide cleavage and carboxypeptidase Y digestion. Binding affinity of iodinated AM analogues was evaluated by competition and saturation binding experiments on dog lung preparations. Results: In this study, we demonstrated that, upon lactoperoxidase oxidation, iodination occurred at Tyr{sup 1} and that this radioligand retained higher binding affinity and specificity over preparations obtained through chemical oxidation. Conclusions: These results emphasize the fact that even a small chemical modification, i.e. iodination, might deeply modify the pharmacological profile of a compound and support observations that the C-terminal tail of human AM plays an important role in the AM receptor binding process. Consequently, incorporation of a radionuclide to produce an AM-based nuclear medicine agent should privilege the N-terminus of the molecule.

Determination of iodine 129 in vegetables using neutron activation analysis

International Nuclear Information System (INIS)

Quintana, Eduardo E.; Thyssen, Sandra M.; Bruno, Hector A.

1999-01-01

The developed methodology allows the determination of iodine 129 in vegetables, using neutron activation analysis. The chemical treatment removes the interferences present in these matrixes, as well as the bromine 82 originated in the activation process. The experimental method for the determination of iodine 129 by neutron activation analysis involves five steps: 1- digestion by alkaline fusion; 2- pre-irradiation purification of iodine 129 by distillation followed by solvent extraction, and adsorption on activated charcoal by distillation; 3- neutron irradiation; 4- post-irradiation purification of iodine 130 by distillation followed by solvent extraction; 5- gamma spectrometry. A chemical recovery of 95 % is obtained in the distillations, measured using iodine 131 as tracer. The whole process recovery is within 70 % and 85 %. The detection limit is 2 mBq/kg of sample, but several factors affect this value, such as type of vegetable, natural iodine concentration, irradiation time and neutron flux. The methodology developed is applied at environmental surveillance with safeguards proposes, in the detection of undeclared reprocessing of irradiated fuel. (authors)

The determination of iodine in biological media using radioactivation analysis (1962)

International Nuclear Information System (INIS)

Comar, D.

1962-06-01

The object of this study is to show that the application of radioactivation analysis to the determination of iodine in biological media makes it possible to measure iodine concentrations of the order of 0.0001 μg. After a review of the chemical methods with a mention of the difficulties they present, the optimum conditions for the determination of iodine in biological liquids are given. Three methods are described: - the first consists of a chemical treatment which liberates the protein bound iodine in an inorganic form. After distillation this iodine is irradiated in a flux of thermal neutrons. The induced radioactivity is compared to that of a standard sample irradiated in the same conditions by γ spectrometry. - the second method which is of more general application consists in irradiating the sample and then extracting the iodine; its induced radio-activity is then measured by β-counting. - the third method measures the iodine directly in the thyroid tissue by anti-compton spectrometry. The sensitivity, the reproducibility and the accuracy are discussed. Some applications are described: determination of iodine in its various organic forms in serum, determination of iodine in urines, in food-stuffs, etc., in the thyroid tissue, etc. (author) [fr

Evaluation method of iodine re-evolution from an in-containment water pool after a loss of coolant accident, Part I: pH estimation of a solution with various chemicals

International Nuclear Information System (INIS)

Kim, Tae Hyeon; Jeong, Ji Hwan

2016-01-01

Highlights: • It is required to evaluate re-evolved iodine from sump water after LOCA. • pH evaluation based on Gibbs free energy minimization. • Program was developed to evaluate chemical equilibrium and pH solutions. • Predictions are in good agreement with experimental data. - Abstract: Radioactive iodine, which is released into the atmosphere of the containment building, is absorbed into the containment spray water and dissolved to be ionized. This iodine-rich water is then transported to the in-containment refueling water storage tank (IRWST) in APR1400 nuclear power plants. When the pH of the water is below 7, the dissolved iodine converts to molecular iodine and re-evolves from the water and returns to the atmosphere. A series of studies have been conducted in order to evaluate the iodine re-evolution from the IRWST. This study consists of two parts: the pH evaluation method and the evaluation of the iodine re-evolution. This paper presents the first part, i.e. the pH evaluation method. The equilibrium concentrations of various chemicals in a solution are determined at the minimum Gibbs’ free energy. This method is useful for complex reactant problems rather than equilibrium constants method because the latter method requires numerous equilibrium constants and there might be missing equilibrium constants associated with the solution. The calculated pH values of solutions are compared with the experimental measurements in order to validate this method and the thermodynamic data of the chemicals incorporated into the program. The estimated values for solutions are in good agreement with the experimental measurements within a difference of less than 3.3%.

Geochemical Cycling of Iodine Species in Soils

International Nuclear Information System (INIS)

Hu, Q.; Moran, J.E.; Blackwood, V.

2007-01-01

Iodine is an important element in studies of environmental protection and human health, global-scale hydrologic processes and nuclear nonproliferation. Biogeochemical cycling of iodine in soils is complex, because iodine occurs in multiple oxidation states and as inorganic and organic species that may be hydrophilic, atmophilic, and biophilic. In this study, we applied new analytical techniques to study the content and speciation of stable iodine in representative surface soils, and sorption and transport behavior of iodine species (iodide, iodate, and 4-iodoaniline) in sediments collected at numerous nuclear facilities in the United States, where anthropogenic 129 I from prior nuclear fuel processing activities poses an environmental risk. The surface soil samples were chosen for their geographic locations (e.g., near the ocean or nuclear facilities) and for their differing physico-chemical characteristics (organic matter, texture, etc). Extracted solutions were analyzed by IC and ICP-MS methods to determine iodine concentrations and to examine iodine speciation (iodide, iodate, and organic iodine). In natural soils, iodine is mostly (nearly 90% of total iodine) present as organic species, while inorganic iodine becomes important (up to 50%) only in sediments with low organic matter. Results from laboratory column studies, aimed at examining transport of different iodine species, showed much greater retardation of 4-iodoaniline than iodide or iodate. Careful attention must be given to potential interconversion among species when interpreting the biogeochemical behavior of iodine in the environment. In addition to speciation, input concentration and residence time effects will influence the biogeochemical cycling of anthropogenic 129I deposited on surface soils

Physico-chemical aspects of the bovine growth hormone iodination by the electrolytic method

International Nuclear Information System (INIS)

Caro, R.A.; Ciscato, V.A.; Giacomini, S.M.V. de; Quiroga, S.; Kurcbart, H.; Radicella, R.

1975-04-01

With a view to studying the mechanism by which iodine is incorporated into the bovine somatotropin molecule, labelling was carried out by the electrolytic method (pH7.4, current 20 μA) as a function of time for various total iodine/protein ratios. In all cases the labelling yields were determined by paper electrophoresis. The corresponding degree of iodination was calculated on the basis of the values obtained and knowledge of the amount of reacting protein, values greater than 12 being obtained in many cases. Enzymatic hydrolysis was carried out on all the samples obtained and in the hydrolysates an increase in free iodide was observed which became more manifest as the iodide/protein molar ratio increased. The percentage of radioactivity from monoiodotyrosine and diiodotyrosine was determined for the various degrees of iodination from chromatograms of the hydrolysates. For an iodination value of 12, diiodotyrosine radioactivity of 70% was found. When the degree of relative iodination for each iodide/protein molar ratio is calculated from the hydrolysis data, it can be seen that only 75% of the total number of available places in the tyrosine residues accept the incorporation of iodine. This fact suggests that not all tyrosine residues are equally accessible. (author)

Nuclear medicine markers of tumor oxygenation and radioresistance

International Nuclear Information System (INIS)

Chapman, J. Donald; Schneider, R.H.; Stobbe, C.C.; Kim, E.; Engelhardt, E.L.; Coia, L.

1996-01-01

Purpose/Objective: The objective of this research project was to synthesize, purify, radiolabel and characterize second-generation nuclear medicine markers of tissue oxygenation with properties superior to iodoazomycin arabinoside (IAZA) and to validate the hypoxia-marking activity of optimal compounds by independent measurements of tumor oxygenation and tumor radioresistance. Materials and Methods: Six hypoxic markers of the iodoazomycin nucleoside class with water solubilities greater than IAZA were synthesized by published procedures. The markers were purified, chemically characterized and labeled with Iodine-125 or Iodine-131. Absolute rates of marker ligation to the macromolecules of hypoxic EMT-6 tumor cells in vitro were determined as a function of marker concentration and used to establish relative marker effectiveness. Hypoxic marking activity in tumors was determined from tumor/blood (T/B) and tumor/muscle (T/M) ratios of radiolabelled marker in EMT-6 tumor-bearing C.B17/Icr scid mice. The optimal marker was administered to R3327-H and R3327-AT tumor-bearing Fischer X Copenhagen rats for estimates of tumor oxygenation by T/B and T/M ratios. Oxygen distributions in the same tumors were obtained with the Eppendorf pO 2 Histograph. The radioresistance of individual tumors was determined from in vitro plating efficiencies of cells released from tumors which had been irradiated in vivo with 20 Gy Cs-137 γ-rays. Results: Of the six iodinated azomycin nucleosides investigated, five were novel markers and all had water solubilities higher than IAZA. Iodinated azomycin xylopyranoside (β-D-IAZXP) was selected as the optimal marker of this class since it 1) exhibited the highest absolute rate of ligation to hypoxic tumor cells in vitro, 2) had the fastest plasma clearance rate in tumor-bearing mice and 3) yielded high T/B ratios in both the mouse and rat tumor models employed in this study. Planar nuclear medicine images of (I-131) β-D-IAZXP in tumor-bearing rats

Regeneration of the iodine isotope-exchange efficiency for nuclear-grade activated carbons

International Nuclear Information System (INIS)

Deitz, V.R.

1985-01-01

The removal of radioactive iodine from air flows passing through impregnated activated carbons depends on a minimum of three distinguishable reactions: (1) adsorption on the carbon networks of the activated carbons, (2) iodine isotope exchange with impregnated iodine-127, and (3) chemical combination with impregnated tertiary amines when present. When a carbon is new, all three mechanisms are at peak performance and it is not possible to distinguish among the three reactions by a single measurement; the retention of methyl iodide-127 is usually equal to the retention of methyl iodide-131. After the carbon is placed in service, the three mechanisms of iodine removal are degraded by the contaminants of the air at different rates; the adsorption process degrades faster than the other two. This behavior will be shown by comparisons of methyl iodide-127 and methyl iodide-131 penetration tests. It was found possible to regenerate the iodine isotope-exchange efficiency by reaction with airborne chemical reducing agents with little or no improvement in methyl iodine-127 retention. Examples will be given of the chemical regeneration of carbons after exhaustion with known contaminants as well as for many carbons removed from nuclear power operations. The depth profile of methyl iodide-131 penetration was determined in 2-inch deep layers before and after chemical treatments

Use of Hopcalite derived Cu-Mn mixed oxide as Oxygen Carrier for Chemical Looping with Oxygen Uncoupling Process

OpenAIRE

Adánez-Rubio, Iñaki; Abad Secades, Alberto; Gayán Sanz, Pilar; Adánez-Rubio, Imanol; Diego Poza, Luis F. de; Garcia-Labiano, Francisco; Adánez Elorza, Juan

2016-01-01

Chemical-Looping with Oxygen Uncoupling (CLOU) is an alternative Chemical Looping process for the combustion of solid fuels with inherent CO2 capture. The CLOU process needs a material as oxygen carrier with the ability to give gaseous O2 at suitable temperatures for solid fuel combustion, e.g. copper oxide and manganese oxide. In this work, treated commercial Carulite 300® was evaluated as oxygen carrier for CLOU. Carulite 300® is a hopcalite material composed of 29.2 wt.% CuO and 67.4 wt.% ...

Iodine behavior in containment under LWR accident conditions

International Nuclear Information System (INIS)

Wisbey, S.J.; Beahm, E.C.; Shockley, W.E.; Wang, Y.M.

1986-01-01

The description of containment iodine behavior in reactor accident sequences requires an understanding of iodine volatility effects, deposition and revaporization/resuspension (from surfaces and aerosols), chemical changes between species, and mass transport. The experimental work in this program has largely centered on the interactions of iodine in or with water pools. The formation of volatile iodine, as I 2 or organic iodides, is primarily dependent on radiation and solution pH. Lower pH results in increased formation of volatile iodine species; thus, for example, a pH of 3.05 resulted in a conversion of I - to I 2 that was more than two orders of magnitude greater than tests run at pH 6.1 or 6.8. The formation or organic iodides involving water pools has been linked to the presence of iodine as I 2 , the solution/gas contact, and to the type of organic material

Iodine removal in containment filtered venting system during nuclear accident

International Nuclear Information System (INIS)

Bera, Subrata; Deo, Anuj Kumar; Nagrale, D.B.; Paul, U.K.; Prasad, M.; Gaikwad, A.J.

2015-01-01

Post Fukushima nuclear accident, containment filtered venting system is being introduced in Indian nuclear power plant to strengthen the defense in depth safety barrier by depressurizing the containment building along with minimization of radioactivity release to environment during a severe accident. Radioactive iodine is one of the major contributors to radiation dose during early release phase of a severe accident. Physical and Chemical form of iodine and iodine bearing compounds includes particulates, elemental and organic. In the most efficient design of CFVS, wet scrubbing mechanism has been employed through use of venture scrubber. The Iodine removal process in wet scrubber involves two processes: chemical reaction in highly alkaline aqueous solution and impingement of particulates with water droplets produced in the venturi nozzle. In this paper, venturi has been modeled using the Calvert model. The variation of efficiency has been estimated for the different particle sizes. The impact of the shape parameter of log-normal distribution on the amount of scrubbed iodine has also been assessed. Release phase wise the scrubbed amount of iodine in the venturi based CFVS system has been estimated for a typical BWR. (author)

Doping characteristics of iodine on as-grown chemical vapor deposited graphene on Pt

Energy Technology Data Exchange (ETDEWEB)

Kim, HoKwon, E-mail: hknano@gmail.com [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Renault, Olivier [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Tyurnina, Anastasia; Guillet, Jean-François; Simonato, Jean-Pierre [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LITEN/DTMN, F-38054 Grenoble (France); Rouchon, Denis; Mariolle, Denis; Chevalier, Nicolas [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Dijon, Jean [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LITEN/DTMN, F-38054 Grenoble (France)

2015-12-15

Using laboratory X-ray photoelectron emission microscopy (XPEEM), we investigated the doping efficiency and thermal stability of iodine on as-grown graphene on Pt. After iodine adsorption of graphene in saturated vapor of I{sub 2,} monolayer and bilayer graphene exhibited work function of 4.93 eV and 4.87 eV, respectively. Annealing of the doped monolayer graphene at 100 °C led to desorption of hydrocarbons, which increased the work function of monolayer graphene by ~0.2 eV. The composition of the polyiodide complexes evolved upon a step-by-step annealing at temperatures from 100 °C to 300 °C while the work-function non-monotonically changed with decreasing iodine content. The iodine dopant was stable at relatively high temperature as a significant amount of iodine remained up to the annealing temperature of 350 °C. - Highlights: • Laboratory XPEEM demonstrates that iodine can effectively p-dope as-grown graphene on Pt with a work-function value up to 5.1 eV. • On the other hand, residual hydrocarbon contamination decreases the work function by up to ~0.2 eV. • The spontaneous intercalation of as-grown few-layered graphene is not easily feasible. • The iodine dopant was not completely removed up to the annealing temperature of 350 °C. • The I{sub 3}{sup −} and I{sub 5}{sup −} polyiodide content ratio of I-doped Gr/Pt decreases with annealing temperature.

Investigation of alumino-phosphate glasses for iodine conditioning

International Nuclear Information System (INIS)

Lemesle, T.

2013-01-01

Iodine 129 is a long-lived intermediate level radioactive waste, which is currently managed by isotopic dilution. In view of an alternative management by geological disposal, we aimed at developing phosphate glasses of the AgI-Ag 2 O-P 2 O 5 -Al 2 O 3 system, elaborated at low temperature and without iodine volatilization. Alumina is expected to induce crosslinking of the phosphate network and thus to improve the thermal and chemical properties. To define a glass composition that meets the specifications, we varied the level of iodine, the Ag 2 O/P 2 O 5 ratio and alumina content. For 1 g.cm -3 of iodine, SEM-EDS observations indicate that alumina solubility is limited to 0.5% mol., independently of Ag 2 O/P 2 O 5 ratio. The structural study by 31 P, 27 Al and 109 Ag MAS NMR, shows that aluminum adopts an octahedral coordination that effectively contributes to the crosslinking of the glassy network and iodine is incorporated without clustering. 31 P- 27 Al NMR correlations confirmed the presence of an alumino-phosphate network, and 31 P- 31 P correlations indicate that iodine does not change the connectivity of the glass network. The glass composition 28,8AgI-44,2Ag 2 O-26,5P 2 O 5 -0,5Al 2 O 3 presents the best compromise between the level of incorporation of iodine and the chemical durability, has a glass transition temperature of 123 C and an initial alteration rate in pure water at 50 C of 6 g.m -2 .d -1 . The long-term behavior of this glass is controlled by a post-alteration structure based on pyrophosphate, which holds nearly 80% of the initial iodine. (author) [fr

Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping

Energy Technology Data Exchange (ETDEWEB)

Pan, Wei-Ping; Cao, Yan

2012-11-30

Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improves the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen

Anisotropic chemical strain in cubic ceria due to oxygen-vacancy-induced elastic dipoles.

Science.gov (United States)

Das, Tridip; Nicholas, Jason D; Sheldon, Brian W; Qi, Yue

2018-06-06

Accurate characterization of chemical strain is required to study a broad range of chemical-mechanical coupling phenomena. One of the most studied mechano-chemically active oxides, nonstoichiometric ceria (CeO2-δ), has only been described by a scalar chemical strain assuming isotropic deformation. However, combined density functional theory (DFT) calculations and elastic dipole tensor theory reveal that both the short-range bond distortions surrounding an oxygen-vacancy and the long-range chemical strain are anisotropic in cubic CeO2-δ. The origin of this anisotropy is the charge disproportionation between the four cerium atoms around each oxygen-vacancy (two become Ce3+ and two become Ce4+) when a neutral oxygen-vacancy is formed. Around the oxygen-vacancy, six of the Ce3+-O bonds elongate, one of the Ce3+-O bond shorten, and all seven of the Ce4+-O bonds shorten. Further, the average and maximum chemical strain values obtained through tensor analysis successfully bound the various experimental data. Lastly, the anisotropic, oxygen-vacancy-elastic-dipole induced chemical strain is polarizable, which provides a physical model for the giant electrostriction recently discovered in doped and non-doped CeO2-δ. Together, this work highlights the need to consider anisotropic tensors when calculating the chemical strain induced by dilute point defects in all materials, regardless of their symmetry.

Experimental and analytical studies of iodine mass transfer from xenon-iodine mixed gas bubble to liquid sodium pool

International Nuclear Information System (INIS)

Miyahara, S.; Sagawa, N.; Shimoyama, K.

1996-01-01

In the fuel pin failure accident of a liquid metal fast reactor, volatile fission products play an important role in the assessment of radiological consequences. Especially the radioisotopes of elemental iodine are important because of their high volatility and of the low permissible dose to human thyroid. The released iodines are known to be retained in the coolant sodium as sodium iodide due to the chemical affinity between alkali metals and halogens. However, the xenon and krypton released with iodines into the sodium pool as bubbles may influence the reaction rate of iodine with sodium during the bubble rising. So far, the only few experimental results have been available concerning the decontamination factor (DF: the ratio of the initial iodine mass in the mixed gas bubble to the released mass into the cover gas) of iodine in this phenomenon. Therefore, experimental and analytical studies were carried out to study the mass transfer of iodine from a xenon-iodine mixed gas bubble to the liquid sodium pool. In the experiments, the bubble was generated in the sodium pool by cracking a quartz ball which contains the xenon-iodine mixed gas and then, the mixed gas released into the argon cover gas was collected to determine the transferred iodine mass into the pool. A rising velocity of the bubble was measured by Chen-type void sensors arranged vertically in the pool. From the measured rising velocity and another observation of bubble behavior in simulated water experiments, it is found that the generated bubble breaks up into several smaller bubbles of spherical cap type during the rising period. Transferred iodine mass per unit initial bubble volume from the bubble to the sodium pool shows increases with increasing time and the initial iodine concentration. A mass transfer rate obtained by differentiating the transferred iodine mass with respect to the time indicates a rapid decrease just after the bubble generation and a slow decrease for the successive period

Epidemiological trends of iodine-related thyroid disorders: an example from Slovenia.

Science.gov (United States)

Gaberšček, Simona; Zaletel, Katja

2016-06-01

The epidemiology of thyroid disorders is significantly associated with iodine supply. In 1999, Slovenia increased iodine content in kitchen salt from 10 mg to 25 mg of potassium iodide per kg of salt. According to the WHO criteria, Slovenia shifted from a mildly iodine-deficient country to a country with adequate iodine intake. Ten years after the increase in iodine intake, the incidence of diffuse goitre and thyroid autonomy decreased. Now patients with diffuse goitre and thyroid autonomy reach older age than the patients before the increase in iodine intake. In addition, patients with thyroid autonomy are less frequently hyperthyroid than ten years ago and iodine-induced hyperthyroidism is less severe. The incidence of highly malignant thyroid carcinoma has also dropped. However, the incidence of Hashimoto's thyroiditis increased, most probably in genetically predisposed individuals. Over the last ten years, many animal and in vitro studies evaluated the effects of endocrine disrupting chemicals (EDC) on various aspects of the thyroid function. They mostly studied the effects of polychlorinated biphenyls (PCBs) and dioxins, brominated flame retardants, phthalates, bisphenol A, perfluorinated chemicals, and perchlorate. However, human studies on the effects of EDCs on the thyroid function are very scarce, especially the long-term ones. What they do suggest is that PCBs and dioxins interfere with the transport of thyroid hormones and adversely affect the thyroid function. Many authors agree that iodine deficiency predisposes the thyroid gland to harmful effects of EDCs. Therefore the effects of EDCs in iodine-deficient areas could be more severe than in areas with adequate iodine intake.

Theoretical and experimental investigations on the behaviour of iodine during severe accidents: volatile iodine. Final report

International Nuclear Information System (INIS)

Funke, F.; Zeh, P.; Greger, G.U.; Hellmann, S.

1999-01-01

Analysis of the consequences of severe accidents in nuclear power plants requires knowledge of the behaviour of radionuclides relevant from the radiological viewpoint, especially the iodine. The current modelling of iodine behaviour is not conclusive, owing to insufficiently known data. This project is intended to eliminate some of these data gaps in critical areas. 350 tests on the radiation-induced oxidation of elemental iodine (I 2 ) in the containment atmosphere were performed yielding an extended database. Moreover, irradiation tests were performed on the formation and decomposition of ozone which is a reaction partner for I 2 . The reaction with ozone converts volatile I 2 into non-volatile iodine oxides or iodate. An improved kinetic modelling was developed for the iodine accident code IMPAIR. Now the model is valid also for steam-containing atmospheres and, additionally, considers dose rate and thus the actual ozone concentration. An assessment of the literature concludes that β and γ radiation have no different impact on iodine chemistry and thus do not need to be modelled separately in iodine accident codes. An assessment of the literature shows a partly significant chemical interaction of volatile iodine with aerosols. Since such reactions lead to a faster decrease of volatile iodine at least at high aerosol concentrations, a modelling should be foreseen in the future. In the frame of the international ISP-41 project, calculations to an integral test in the Canadian Radioiodine Test Facility (RTF) were performed with IMPAIR. The existing model of the radiation-induced I 2 formation in the sump in IMPAIR is identified as a weakness requiring future improvement. A theoretical assessment on the iodine chemistry in the droplets of a spray system concludes that a modelling is necessary in case of spraying with fresh water, and that this is already contained in available spray models. During recirculation spraying in an examplary, hypothetical EPR case, no

Controlling hazardous chemicals in microreactors: Synthesis with iodine azide

Directory of Open Access Journals (Sweden)

Johan C. Brandt

2009-06-01

Full Text Available Aromatic aldehydes have been converted into the corresponding carbamoyl azides using iodine azide. These reactions have been performed safely under continuous flow reaction conditions in microreactors.

Aged anthropogenic iodine in a boreal peat bog

International Nuclear Information System (INIS)

Maillant, S.; Sheppard, M.I.; Denys, S.; Leclerc Cessac, E.

2004-01-01

Iodine-129 is a radionuclide of major concern in the international safety assessments for deep geological storage and disposal of nuclear waste because it migrates quickly through the geosphere to the biosphere and then from the soil to humans through the food-chain. However, in organic soils the 129 I may be immobilized over a long time period, and so these soils represent a potential accumulation point in the biosphere. Effects of long residence times of iodine in soils are scarce. The present paper gives some insight on the aging of stable iodine, under natural conditions. Stable iodine was introduced as KI in 1987 at the base of a small natural sphagnum bog to simulate arrival of iodine via a groundwater discharge from the geosphere. Previous data revealed the spread of the iodine outwards spatially from the basal spike and also recorded its rise towards the bog surface. Fifteen years later, the groundwater, the soil and the vegetation have been sampled and analyzed for iodine. The results we will present give insight on the mobility of 'aged' iodine with time, the retention properties of the peat, and provide iodine transfer factors for native boreal plant species. The data show iodine: - continues to slowly spread from the spike after 15 years, - is more strongly retained on the solid phase at the surface than at depth, - the chemical structure of the peat may influence the retention of iodine as shown by NMR analysis, - iodine retention has become greater with time, and - herbaceous species are the greatest accumulators. This study demonstrates bogs present good sinks for iodine and limit the transfer of iodine to some of the 'wildlife' food-chains. (author)

A Microscale Approach to Chemical Kinetics in the General Chemistry Laboratory: The Potassium Iodide Hydrogen Peroxide Iodine-Clock Reaction

Science.gov (United States)

Sattsangi, Prem D.

2011-01-01

A microscale laboratory for teaching chemical kinetics utilizing the iodine clock reaction is described. Plastic pipets, 3 mL volume, are used to store and deliver precise drops of reagents and the reaction is run in a 24 well plastic tray using a total 60 drops of reagents. With this procedure, students determine the rate of reaction and the…

The chemical behaviour of iodine-129 in the process of radwaste conditioning

International Nuclear Information System (INIS)

Schon, T.

1993-11-01

During radwaste reprocessing, elemental I-129 may almost completely be transferred to the dissolver off-gas stream. The AC 6120 adsorbent, consisting of high-heated, amorphous silicic acid impregnated with silver nitrate, proved to be particularly efficient for removing the iodine from the off-gas. In a gas-solid reaction, the elemental iodine is converted into solid silver iodide and silver iodate. The reaction's stoichiometry depends on the loading temperature, with temperatures between 30 and 80 C resulting in a ratio of five between the reaction products of AgI and AgIO 3 , while with temperatures higher than that, up to 150 C, the ratio is three. For assessing the acceptability of the iodine-bearing AC 6120 as a waste product to be emplaced in a salt rock repository, the ratio of the reaction products is one of the main criteria. The products solubility and its complexation reactions with chloride-bearing brines are two other important criteria, especially with a view to the not completely hypothetical accident type of 'water ingress into the salt cavern'. Leaching experiments have shown that in this event, between 30 and over 60% of the waste product's iodine inventory would be leached out within only seven days. Thus AC 6120 is not a candidate adsorbent for immobilization of iodine 129 in a waste product. (orig./HP) [de

Iodine Deficiency

Science.gov (United States)

... Fax/Phone Home » Iodine Deficiency Leer en Español Iodine Deficiency Iodine is an element that is needed ... world’s population remains at risk for iodine deficiency. Iodine Deficiency FAQs WHAT IS THE THYROID GLAND? The ...

Chemistry of fission product iodine under nuclear reactor accident conditions

International Nuclear Information System (INIS)

Malinauskas, A.P.; Bell, J.T.

1986-01-01

The radioisotopes of iodine are generally acknowledged to be the species whose release into the biosphere as a result of a nuclear reactor accident is of the greatest concern. In the course of its release, the fission product is subjected to differing chemical environments; these can alter the physicochemical form of the fission product and thus modify the manner and extent to which release occurs. Both the chemical environments which are characteristic of reactor accidents and their effect in determining physical and chemical form of fission product iodine have been studied extensively, and are reviewed in this report. 76 refs

Effect of nitrogen and oxygen on radiolysis of iodide solution

Energy Technology Data Exchange (ETDEWEB)

Karasawa, H; Endo, M [Hitachi Ltd., Power and Industrial System R+D Divisions, Ibaraki (Japan)

1996-12-01

The effect of nitrogen and oxygen on radiolysis of iodide solution was examined. Direct decomposition of nitrogen by {gamma}-radiation produced nitric acid to decrease a water pH. This resulted in the iodine formation in the radiolysis of iodide solution. Hydrogen peroxide was produced by the radiolysis of water containing oxygen. This worked a reducing agent to suppress the formation of iodine in the radiolysis of iodide solution. In the analytical model, fourteen iodine species were considered and reaction scheme consisted in 124 reactions. The analytical model could estimate the oxidation state of iodide ions. (author) 4 figs., 4 refs.

Development of a definitive method for iodine speciation in aquatic systems

International Nuclear Information System (INIS)

Reifenhaeuser, C.; Heumann, K.G.

1990-01-01

A definitive method of isotope dilution mass spectrometry (IDMS) was developed to determine four different iodine species in aquatic systems (iodide, iodate and two organoiodine compounds: one of the organic species is chromatographically elutable from a column filled with an anion exchanger resin, the other one is not). The iodine species were analysed after the isotope dilution step with an enriched 129 I spike and after their chromatographic separation. The total iodine concentration was measured after decomposition of organic compounds in the aquatic system by UV irradiation. Different types of natural water samples (river water, water of a pond, moorland lake water) were analysed and important water parameters like pH-value, redox potential, oxygen content and dissolved organic carbon were measured for each of these samples. The total iodine concentration in the different samples differed only slightly in the range of 2-7 μg/l. In most of the moorland lake water samples only the two organoiodine species could be detected. In these samples the concentration of iodide and iodate was less than the detection limit of 0.5 μg/l and 0.1 μg/l, respectively. On the other hand, all four iodine species could be determined in most of the river water samples. Positive correlations were found for the oxygen content of the water samples and the iodate concentration as well as for the redox potential and the anionic organoiodine compound. (orig.)

Methods to determine iodine plate-out

International Nuclear Information System (INIS)

Hougaard, H.; Solgaard, P.; Zak, W.

1986-03-01

A literature study on iodines behaviour after release from irradiated fuel rods and a detailed dscription of the ventilation system in the hot cell facility form the basis of chosen conditions for some preliminary experiments using non-radioactive iodine. The conclusion states that the system is well suited for the purpose as is the method of sampling from the surface of the ventilation duct, while the releasing technique and the chemical analysis has to be further developed, neutron activation analysis being most promising. (author)

Atom interaction propensities of oxygenated chemical functions in crystal packings

Directory of Open Access Journals (Sweden)

Christian Jelsch

2017-03-01

Full Text Available The crystal contacts of several families of hydrocarbon compounds substituted with one or several types of oxygenated chemical groups were analyzed statistically using the Hirshfeld surface methodology. The propensity of contacts to occur between two chemical types is described with the contact enrichment descriptor. The systematic large enrichment ratios of some interactions like the O—H...O hydrogen bonds suggests that these contacts are a driving force in the crystal packing formation. The same statement holds for the weaker C—H...O hydrogen bonds in ethers, esters and ketones, in the absence of polar H atoms. The over-represented contacts in crystals of oxygenated hydrocarbons are generally of two types: electrostatic attractions (hydrogen bonds and hydrophobic interactions. While Cl...O interactions are generally avoided, in a minority of chloro-oxygenated hydrocarbons, significant halogen bonding does occur. General tendencies can often be derived for many contact types, but outlier compounds are instructive as they display peculiar or rare features. The methodology also allows the detection of outliers which can be structures with errors. For instance, a significant number of hydroxylated molecules displaying over-represented non-favorable oxygen–oxygen contacts turned out to have wrongly oriented hydroxyl groups. Beyond crystal packings with a single molecule in the asymmetric unit, the behavior of water in monohydrate compounds and of crystals with Z′ = 2 (dimers are also investigated. It was found in several cases that, in the presence of several oxygenated chemical groups, cross-interactions between different chemical groups (e.g. water/alcohols; alcohols/phenols are often favored in the crystal packings. While some trends in accordance with common chemical principles are retrieved, some unexpected results can however appear. For example, in crystals of alcohol–phenol compounds, the strong O—H...O hydrogen bonds between

Behavior of mercury and iodine during vitrification of simulated alkaline Purex waste

International Nuclear Information System (INIS)

Holton, L.K.

1981-09-01

Current plans indicate that the high-level wastes stored at the Savannah River Plant will be solidified by vitrification. The behavior of mercury and iodine during the vitrification process is of concern because: mercury is present in the waste in high concentrations (0.1 to 2.8 wt%); mercury will react with iodine and the other halogens present in the waste during vitrification and; the mercury compounds formed will be volatilized from the vitrification process placing a high particulate load in the vitrification system off-gas. Twelve experiments were completed to study the behavior of mercury during vitrification of simulated SRP Purex waste. The mercury was completely volatized from the vitrification system in all experiments. The mercury reacted with iodine, chlorine and oxygen to form a fine particulate solid. Quantitative recovery of mercury compounds formed in the vitrification system off-gas was not possible due to high (37 to 90%) deposition of solids in the off-gas piping. The behavior of mercury and iodine was most strongly influenced by the vitrification system atmosphere. During experiments performed in which the oxygen content of the vitrification system atmosphere was low (< 1 vol%); iodine retention in the glass product was 27 to 55%, the mercury composition of the solids recovered from the off-gas scrub solutions was 75 to 85 wt%, and a small quantity of metallic mercury was recovered from the off-gas scrub solution. During experiments performed in which the oxygen content of the vitrification system atmosphere was high (20 vol%), iodide retention in the glass product was 3 to 15%, the mercury composition of the solids recovered from the off-gas scrub solutions was 60 to 80 wt%, and very little metallic mercury was recovered from the off-gas scrub solution

Physical experiments on the utility of non-iodine-containing contrast media

International Nuclear Information System (INIS)

Kirschner, H.; Burmester, U.; Stringaris, K.; Jentsch, F.

1979-01-01

Because of the excellent ability of the CT scanner in analyzing absorption, the use of non-iodine-containing contrast media will be discussed. Experimental studies of the chemical elements with the atomic number Z = 1-83 with a scan tension of 120 kV were made to determine how many atoms of a given element are necessary to replace one iodine atom in an iodine-containing contrast medium, whereby the same contrast enhancement in the scan picture as with the iodine-containing contrast medium is produced. (orig.) 891 ORU/orig. 892 MB [de

The iodine reactivity; La reactivite de l'iode

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The iodine is an important element because it has long life isotopes (such as iodine 129) and a great mobility in natural media. Iodine presents a complex chemistry because of its volatility and its strong redox reactivity. The S.E.C.R. works to better understand the reactivity of this element in different natural, industrial or biological environments. It plays a part in thermochemical sites as a possible way of hydrogen formation. This seminar gives some aspects relative to the chemical reactivity of iodine, since its thermochemistry in the I/S cycles to produce hydrogen to its reactivity in the natural medium and its potential radiological impact. This document includes 4 presentations transparencies dealing with: the {sup 129}I cycle rejected in the low radioactive gaseous and liquid effluents of the La Hague reprocessing plant (C. Frechou); a bibliographic review of iodine retention in soils (F. Bazer-Bachi); the hydrogen production and the iodine/sulfur thermochemical cycle (role of iodine in the process); and the direct characterization by electro-spray ionization mass spectroscopy of iodine fixation by fulvic acids (P. Reiller, B. Amekraz, C. Moulin, V. Moulin)

Total iodine quantification in fluids and tissues from iodine- or iodide-supplemented rats by ion chromatography following microwave-assisted digestion.

Science.gov (United States)

Delgado, Guadalupe; Muñoz-Torres, Carolina; Orozco-Esquivel, Teresa; Anguiano, Brenda; Aceves, Carmen

2015-03-01

Iodine is a crucial component of thyroid hormones, and several reports have shown that iodine per se is implicated in the physiopathology of other organs. Innovative ion chromatography detection following a four-step temperature ramp microwave digestion in 25-50 mM nitric acid was developed to measure total iodine in biological fluids and tissue samples from female Sprague-Dawley rats supplemented with 0.05% molecular iodine (I2) or 0.05% potassium iodide (I(-)) in drinking water. The reported method allows the measurement of total iodine with a limit of quantification of 13.7 μg L(-1), recoveries of 96.3-100.3%, and intra- and inter-assay variations, of 3.5% and 7.4% respectively. Analysis of biological fluids showed that after 48 hours, iodine-supplemented animals exhibited significantly higher levels of total iodine in both serum and urine compared with those supplemented with iodide. The half-life of iodine in serum and urine measured over the first 48 h showed similar patterns for both the I2 (7.89 and 7.76 hours) and I(-) (8.27 and 8.90 hours) supplements. Differential uptake patterns were observed in tissues after 6 days of supplements, with I(-) preferentially retained by thyroid, lactating mammary gland, and milk, and a slightly but significantly higher capture of I2 in pituitary, ovary, and virgin mammary gland. We developed a rapid, selective, and accurate digestion method to process fluid and tissue samples that permits reproducible measurements of total iodine by ion chromatography; iodine or iodide supplement show a similar serum and urine half-life, but organ-specific uptake depends on the chemical form of the iodine supplement.

Limited Influence of Oxygen on the Evolution of Chemical Diversity in Metabolic Networks

Directory of Open Access Journals (Sweden)

Kazuhiro Takemoto

2013-10-01

Full Text Available Oxygen is thought to promote species and biomolecule diversity. Previous studies have suggested that oxygen expands metabolic networks by acquiring metabolites with different chemical properties (higher hydrophobicity, for example. However, such conclusions are typically based on biased evaluation, and are therefore non-conclusive. Thus, we re-investigated the effect of oxygen on metabolic evolution using a phylogenetic comparative method and metadata analysis to reduce the bias as much as possible. Notably, we found no difference in metabolic network expansion between aerobes and anaerobes when evaluating phylogenetic relationships. Furthermore, we showed that previous studies have overestimated or underestimated the degrees of differences in the chemical properties (e.g., hydrophobicity between oxic and anoxic metabolites in metabolic networks of unicellular organisms; however, such overestimation was not observed when considering the metabolic networks of multicellular organisms. These findings indicate that the contribution of oxygen to increased chemical diversity in metabolic networks is lower than previously thought; rather, phylogenetic signals and cell-cell communication result in increased chemical diversity. However, this conclusion does not contradict the effect of oxygen on metabolic evolution; instead, it provides a deeper understanding of how oxygen contributes to metabolic evolution despite several limitations in data analysis methods.

Iodine volatility

International Nuclear Information System (INIS)

Beahm, E.C.; Shockley, W.E.

1984-01-01

The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

Chemistry and mass transport of iodine in containment

International Nuclear Information System (INIS)

Beahm, E.C.; Weber, C.F.; Kress, T.S.; Shockley, W.E.; Daish, S.R.

1988-01-01

TRENDS is a computer code for modeling behavior of iodine in containment. It tracks both chemical and physical changes and features such as calculation of radiation dose rates in water pools , radiolysis effects, hydrolysis, and deposition/revaporization on aerosols and structural surfaces. Every attempt has been made to account for all significant processes. Reaction rate constants for iodine hydrolysis and radiolysis were obtained by a variable algorithm that gives values closely modeling experimental data. TRENDS output provides the distribution of iodine in containment and release from containment as a function of time during a severe accident sequence. Initial calculations with TRENDS have shown that the amount of volatile iodine released from containment is sensitive to the value of the liquid-gas (evaporation) mass transport coefficient for I 2 . 7 refs., 4 figs., 3 tabs

Influence of oxygen on the chemical stage of radiobiological mechanism

International Nuclear Information System (INIS)

Barilla, Jiří; Lokajíček, Miloš V.; Pisaková, Hana; Simr, Pavel

2016-01-01

The simulation of the chemical stage of radiobiological mechanism may be very helpful in studying the radiobiological effect of ionizing radiation when the water radical clusters formed by the densely ionizing ends of primary or secondary charged particle may form DSBs damaging DNA molecules in living cells. It is possible to study not only the efficiency of individual radicals but also the influence of other species or radiomodifiers (mainly oxygen) being present in water medium during irradiation. The mathematical model based on Continuous Petri nets (proposed by us recently) will be described. It makes it possible to analyze two main processes running at the same time: chemical radical reactions and the diffusion of radical clusters formed during energy transfer. One may study the time change of radical concentrations due to the chemical reactions running during diffusion process. Some orientation results concerning the efficiency of individual radicals in DSB formation (in the case of Co60 radiation) will be presented; the influence of oxygen present in water medium during irradiation will be shown, too. - Highlights: • Creation of the mathematical model. • Realization of the model with the help of Continuous Petri nets. • Obtain the time dependence of changes in the concentration of radicals. • Influence of oxygen on the chemical stage of radiobiological mechanism.

Why Do Lithium-Oxygen Batteries Fail: Parasitic Chemical Reactions and Their Synergistic Effect.

Science.gov (United States)

Yao, Xiahui; Dong, Qi; Cheng, Qingmei; Wang, Dunwei

2016-09-12

As an electrochemical energy-storage technology with the highest theoretical capacity, lithium-oxygen batteries face critical challenges in terms of poor stabilities and low charge/discharge round-trip efficiencies. It is generally recognized that these issues are connected to the parasitic chemical reactions at the anode, electrolyte, and cathode. While the detailed mechanisms of these reactions have been studied separately, the possible synergistic effects between these reactions remain poorly understood. To fill in the knowledge gap, this Minireview examines literature reports on the parasitic chemical reactions and finds the reactive oxygen species a key chemical mediator that participates in or facilitates nearly all parasitic chemical reactions. Given the ubiquitous presence of oxygen in all test cells, this finding is important. It offers new insights into how to stabilize various components of lithium-oxygen batteries for high-performance operations and how to eventually materialize the full potentials of this promising technology. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Method for solidification of radioactive iodine-containing solid wastes

International Nuclear Information System (INIS)

Ozawa, Yoshihiro; Funabashi, Kiyomi; Uetake, Naoto.

1987-01-01

Purpose: To process radioactive iodine containing solid wastes as non-leaching solidified wastes with no risk of iodine release. Method: It has been known for the thermal stability of CuI, PbI 2 or adsorbents containing the same that they do not release iodine in an inert gas atmosphere or in a reducing atmosphere at a temperature lower than 480 deg C. In view of the above, adsorbents containing iodine in the chemical form of CuI or PbI 2 , or CuI or powdery PbI 2 per se are sealed and solidified into low melting glass at a temperature of lower than 480 deg C at which no iodine release occurs in a non-oxidative atmosphere. Since the products are vitrified wastes, they scarcely show leaching property and are excellent in durability and stability. (Takahashi, M.)

Radiolytic oxidation of iodine in the containment at high temperature and dose rate

International Nuclear Information System (INIS)

Guilbert, S.; Bosland, L.; Jacquemain, D.; Clement, B.; Andreo, F.; Ducros, G.; Dickinson, S.; Herranz, L.; Ball, J.

2007-01-01

-line measurements of iodine volatilisation during irradiation at elevated temperatures and dose rates. This paper presents a description of the EPICUR facility and an overview of the experiments carried out so far to investigate radiolytic oxidation under those conditions in which data are to date insufficient. Experiments were performed using iodide solutions labelled with radioactive iodine ( 131 I). Gamma spectrometers were used to measure the rate of iodine volatilization on-line at 80 and 120 O C at a dose rate of 1.5 kGy.h -1 . The impact of dissolved oxygen and pH on the production of molecular iodine was also investigated. Tests indicate that iodine volatilization rates increased with decreasing temperature and in the absence of oxygen. On the other hand, the iodine volatility decreases strongly with increasing pH. A comparison with existing experimental data in the field is provided together with perspectives for the modelling work. (author)

Iodine Satellite

Science.gov (United States)

Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew

2015-01-01

The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to

Micro Chemical Oxygen-Iodine Laser (COIL)

Science.gov (United States)

2007-10-01

some of the monthly reports, was to provide effective MEMS-scale thermal insulation to prevent heat leakage. The second, which was ultimately chosen for...this is the first reported demonstration of separation of a liquid-gas mixture below atmospheric pressure using the capillary micropore concept [8]. The...temperature to reach an operating temperature of 243 K. Owing to heat addition through insulated coolant lines and flowmeters, this corresponded to a

Cement materials for cesium and iodine confinement

International Nuclear Information System (INIS)

Nicolas, G.; Lequeux, N.; Boch, P.; Prene, S.

2001-01-01

The following topics were dealt with: radioactive waste storage, cement materials reacting with radioactive cesium and iodine, chemical barrier formation against radioactive pollution, ceramization, long term stability, XRD, PIXE analysis

Adsorption and revaporisation studies on iodine oxide aerosols deposited on containment surface materials in LWR

International Nuclear Information System (INIS)

Tietze, S.; Foreman, M.R.StJ.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.; Tapper, U.; Lamminmaeki, S.; Jokiniemi, J.

2012-12-01

During a hypothetical severe nuclear accident, the radiation field will be very high in the nuclear reactor containment building. As a result gaseous radiolysis products will be formed. Elemental iodine can react in the gaseous phase with ozone to form solid iodine oxide aerosol particles (iodine oxide). Within the AIAS (Adsorption of Iodine oxide Aerosols on Surfaces) project the interactions of iodine oxide (IOx) aerosols with common containment surface materials were investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS, as well as Pt and Pd surfaces from hydrogen recombiners. Non-radioactive and 131 I labelled iodine oxide aerosols were produced with the EXSI CONT facility from elemental iodine and ozone at VTT Technical Research Centre of Finland. The iodine oxide deposits were analysed with microscopic and spectroscopic measurement techniques to identify the kind of iodine oxide formed and if a chemical conversion on the different surface materials occurs. The revaporisation behaviour of the deposited iodine oxide aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 having a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The revaporisated 131 I species from the surfaces were chemically tested for elemental iodine formation. The parameter dominating the degradation of the produced iodine oxide aerosols was humidity. Cu and Zn surfaces were found to react with iodine from the iodine oxide aerosols to form iodides, while no metal iodides were detected for Al and SS samples. Most of the iodine oxide aerosols are assumed to be

Iodine Absorption Cells Purity Testing

Directory of Open Access Journals (Sweden)

Jan Hrabina

2017-01-01

Full Text Available This article deals with the evaluation of the chemical purity of iodine-filled absorption cells and the optical frequency references used for the frequency locking of laser standards. We summarize the recent trends and progress in absorption cell technology and we focus on methods for iodine cell purity testing. We compare two independent experimental systems based on the laser-induced fluorescence method, showing an improvement of measurement uncertainty by introducing a compensation system reducing unwanted influences. We show the advantages of this technique, which is relatively simple and does not require extensive hardware equipment. As an alternative to the traditionally used methods we propose an approach of hyperfine transitions’ spectral linewidth measurement. The key characteristic of this method is demonstrated on a set of testing iodine cells. The relationship between laser-induced fluorescence and transition linewidth methods will be presented as well as a summary of the advantages and disadvantages of the proposed technique (in comparison with traditional measurement approaches.

Method for investigation of various iodine species in the primary coolant of the nuclear power plant in Paks

International Nuclear Information System (INIS)

Volent, G.; Gimesi, O.; Solymosi, J.

1996-01-01

Iodine isotopes formed in the course of fission in nuclear reactors may be present in the primary coolant in different oxidation states, i.e., in different chemical forms. It is important to know the chemical forms and their proportions in order to asses the environmental effect of the emitted iodine and the performance of air filters used in the primary circuit for binding iodine, species, since both depend on the chemical forms in which it is present. Volatile components were separated from water samples taken separately from each block of the nuclear power station by purging with inert gas, then the aerosol, iodine vapour and alkyl iodides were selectively bound on the filter system of the 'KOMBI' sampler. I 3 - , I - , IO - , IO 3 - and IO 4 - left in the aqueous phase after purging were separated by consecutive physical and chemical procedures (extraction, isotope exchange, reduction). The results of the investigations have shown that the water technology used in the Nuclear Power Plant in Paks is appropriate with respect to the radioiodine balance. Iodine was found to be predominant species, and no volatile iodine species were found to be present in the primary coolant. Volatile iodine species sometimes appearing in emissions may be formed from leaching waters due to secondary effects. (author)

Chemical shifts of oxygen-17 NMR in polyoxotungstates

International Nuclear Information System (INIS)

Kazanskij, L.P.; Fedotov, M.A.; Spitsyn, V.I.

1977-01-01

17 O NMR spectra of aqueous solutions containing paratungstate BH 2 W 12 O 42 10- and metatungstate H 2 W 12 O 40 6- anions have been measured. On the basis of the obtained data a scale of chemical shifts for oxygen atoms connected by various bonds with tungsten atoms is suggested. The obtained data are compared with the Raman spectra of crystalline salts and their aqueous solutions. Chemical shifts of 17 O NMR spectra have been also measured in other heteropolyanions

Chemical Speciation Analysis and Environmental Behaviour of ¹²⁷I and ¹²⁹I

DEFF Research Database (Denmark)

Hansen, Violeta

2011-01-01

may be a slow process while along the Baltic Sea surface water reduction of iodate is a relatively fast process. Although suboxic or anoxic condition are encountered in some of the Baltic Sea deep basins, the concentration of 129IO3 - increases with water depth indicating that the reduction of iodate......) in environmental samples are very complex and strongly dependent on several factors, such as water/soil/sediment chemistry, seaweed type, different pH, Eh, quantity and quality of organic matter, microbiological activity as well as differences in contaminant origin. The 129I isotope, where the main inventory has...... in the oxygen deficient bottom water of the Baltic Sea is a slow process. Iodine chemical speciation analysis (as iodide, iodate and total iodine including inorganic and organic iodine species) in lake water samples collected from Denmark and southern Sweden has been carried out. Destruction of organic iodine...

Research and Development on Coatings for Retaining Fission Product Iodine

Energy Technology Data Exchange (ETDEWEB)

Genco, J. M.; Berry, D. A.; Rosenberg, H. S.; Cremeans, G. E.; Morrison, D. L. [Battelle Memorial Institute, Columbus Laboratories, Columbus, OH (United States)

1968-12-15

It is well known that elemental iodine has the propensity for forming charge-transfer complexes with amines. These complexes are stable at ambient temperatures and retain much of this stability at elevated temperatures. Amines also react with methyl iodide and hydrogen iodide to form the quaternary ammonium salts and amine salts, respectively. These chemical properties of amines provide the basis for the development of retentive coatings for fission product iodine. Various amine-containing polymers were studied in steam-air environments at elevated temperatures using dilute quantities of tagged iodine. Both non-condensing and condensing steam conditions were investigated. Several of the polymers showed sorption rates and capacities that would be adequate for the chemical removal of accident-released fission-product iodine and were several times more effective than commercial protective coatings currently being used. The removal capabilities for amine polymers also could be enhanced by impregnating the reactant on a matrix material such as asbestos mat, presumably because the impregnation technique leads to enhanced surface area and porosity. The two most promising coating systems found were 1:10-phenanthroline impregnated upon asbestos and a three component composite film of the co-polymer of Genamid 2000 and Epon 828 as a reactive binder with 1,10-phenanthroline as a reactive filler. The use of a reactive coating as a passive safety system should reduce appreciably the airborne iodine half-life and the hazards associated with iodine release during a nuclear reactor accident. (author)

Is placental iodine content related to dietary iodine intake?

LENUS (Irish Health Repository)

Burns, R

2011-08-01

Delivery of iodine to the foetus depends not only on maternal dietary iodine intake but also on the presence of a functioning placental transport system. A role for the placenta as an iodine storage organ has been suggested, and this study compares the iodine content of placentas from women giving birth at term in Ireland and Iran, areas with median urinary iodine of 79 and 206 μg\\/l respectively.

Bacterial contribution to iodine volatilization in the environment

Energy Technology Data Exchange (ETDEWEB)

Amachi, S; Kasahara, M; Fujii, T [Chiba Univ., Dept. of Bioresources Chemistry, Matsudo, Chiba (Japan); Muramatsu, Y [National Inst. of Radiological Sciences, Chiba (Japan)

2003-09-01

The roles of microorganisms in iodine volatilization from the environment were studied. More than 100 bacterial strains were isolated from various environments such as soils, seawater and marine sediments, and were examined their capacities for volatilizing iodine. Approximately 40% of these bacteria showed significant capacities for volatilizing iodine. Gas chromatographic determinations revealed that the chemical species of gaseous iodine is methyl iodide (CH{sub 3}I). Phylogenetic analysis based on 16S ribosomal DNA showed that these 'iodine-volatilizing bacteria' are widely distributed through the bacterial domain. The iodide-methylating reaction was mediated by an enzyme protein with S-adenosyl-L-methionine (SAM) as the methyl donor. We then estimated bacterial contribution to iodine volatilization from soils. Iodine in soils was volatilized mainly as CH{sub 3}I. CH{sub 3}I emission was enhanced in the presence of glucose or yeast extract, but was inhibited by autoclaving of soils. Little CH{sub 3}I was produced under anaerobic conditions. Furthermore, the addition of streptomycin and tetracycline, antibiotics which inhibit bacterial growth, strongly inhibited CH{sub 3}I emission, while a fungal inhibitor cycloheximide caused little effect. These results suggest that iodine in soils is volatilized as CH{sub 3}I mainly by the action of aerobic soil bacteria. Similar experiment was carried out by using sea water samples. The emission of iodine from sea waters occurred biologically, and bacterial (and also other microbial) contribution was confirmed. Our results suggest that iodine is methylated and volatilized into the atmosphere as a result of bacterial activities. Since bacteria are so abundant and widespread in the environments, they may significantly contribute to global iodine volatilization. This indicates that if {sup 129}I would be released from nuclear facilities, weapons testing or ground storage of nuclear wastes, the pathway of volatilization by

Gas to liquid to solid transition in halogen hot atom chemistry. 6. Product formation routes and chemical selectivity of high energy iodine reactions with butyne isomers

International Nuclear Information System (INIS)

Garmestani, S.K.; Firouzbakht, M.L.; Rack, E.P.

1979-01-01

Reactions of recoil produced iodine-128 with isomers of butyne were studied in gaseous, high pressure, and condensed phase conditions, with rare gas additives and in the presence and absence of radical scavengers (I 2 and O 2 ). It was found that recoil iodine-128 reactions were initiated by thermal electronically excited I + species for both 1-butyne and 2-butyne systems. While the diverse and complex nature of the reactions cannot be explained by simple chemical parameters, comparisons among the alkyne systems demonstrate preferential attack of iodine at the triple bond resulting, mainly, in electronically excited intermediates. A comparison of the various product formation routes results in the characterization of general traits common to the alkynes. 6 figures, 4 tables

Present status of iodine research at IPSN

Energy Technology Data Exchange (ETDEWEB)

Bardelay, J [IPSN/DPEA/SEAC (France)

1996-12-01

Since several years, IPSN has conducted an effort in order to evaluate the release of radioactive iodine in case of hypothetical severe accident in a realistic manner. This source-term evaluation is performed with IODE code which is a module of the EXCADRE system of codes. This code is validated against: -analytical experiments: in these experiments, IPSN studies radiolytic effects and chemical processes in the sump, organic formation, mass transfer, effect of spray (CARAIDAS experiment), - the CAIMAN semi global experiment; this experiment will allow to study the phenomena linked to iodine behavior under representative containment geometry in the presence of painted surfaces and global irradiation, - the PHEBUS FP program. The paper consists to describe succinctly the current status of IODE and the various experiments for its validation. In case of hypothetical severe accident iodine can induce important perturbations of human organism. The effects are principally radiological, in particular on the thyroid. At short term, radioactive iodine is the most important contributor for the sanitary risk. It represents 55% of effective dose and 92% of thyroid dose at 10 km in case of controlled rejects with current assumptions. This is the reason why it must be actively studied. In France, the safety evaluations are performed with mechanistic codes or lumped parameter codes like EXCADRE which contains a module devoted to iodine studies: IODINE. The objective of the French experimental program on iodine is to understand and quantify important phenomena in order to put kinetic parameters in IODE module. The experiments can be classified in analytical experiments, the semi-global experiment CAIMAN which takes into account different phenomena studied in analytical experiments and the global experiment PHEBUS PF, not only devoted to iodine behavior study. In the following text we will present the needs of IODINE code and these different experiments. (author).

Present status of iodine research at IPSN

International Nuclear Information System (INIS)

Bardelay, J.

1996-01-01

Since several years, IPSN has conducted an effort in order to evaluate the release of radioactive iodine in case of hypothetical severe accident in a realistic manner. This source-term evaluation is performed with IODE code which is a module of the EXCADRE system of codes. This code is validated against: -analytical experiments: in these experiments, IPSN studies radiolytic effects and chemical processes in the sump, organic formation, mass transfer, effect of spray (CARAIDAS experiment), - the CAIMAN semi global experiment; this experiment will allow to study the phenomena linked to iodine behavior under representative containment geometry in the presence of painted surfaces and global irradiation, - the PHEBUS FP program. The paper consists to describe succinctly the current status of IODE and the various experiments for its validation. In case of hypothetical severe accident iodine can induce important perturbations of human organism. The effects are principally radiological, in particular on the thyroid. At short term, radioactive iodine is the most important contributor for the sanitary risk. It represents 55% of effective dose and 92% of thyroid dose at 10 km in case of controlled rejects with current assumptions. This is the reason why it must be actively studied. In France, the safety evaluations are performed with mechanistic codes or lumped parameter codes like EXCADRE which contains a module devoted to iodine studies: IODINE. The objective of the French experimental program on iodine is to understand and quantify important phenomena in order to put kinetic parameters in IODE module. The experiments can be classified in analytical experiments, the semi-global experiment CAIMAN which takes into account different phenomena studied in analytical experiments and the global experiment PHEBUS PF, not only devoted to iodine behavior study. In the following text we will present the needs of IODINE code and these different experiments. (author)

The kinetic study of oxidation of iodine by hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Cantrel, L [Institut de Protection et de Surete Nucleaire, IPNS, CEN Cadarache, Saint Paul lez Durance (France); Chopin, J [Laboratoire d` Electrochimie Inorganique, ENSSPICAM, Marseille (France)

1996-12-01

Iodine chemistry is one of the most important subjects of research in the field of reactor safety because this element can form volatile species which represent a biological hazard for environment. As the iodine and the peroxide are both present in the sump of the containment in the event of a severe accident on a light water nuclear reactor, it can be important to improve the knowledge on the reaction of oxidation of iodine by hydrogen peroxide. The kinetics of iodine by hydrogen peroxide has been studied in acid solution using two different analytical methods. The first is a UV/Vis spectrophotometer which records the transmitted intensity at 460 nm as a function of time to follow the decrease of iodine concentration, the second is an amperometric method which permits to record the increase of iodine+1 with time thanks to the current of reduction of iodine+1 to molecular iodine. The iodine was generated by Dushman reaction and the series of investigations were made at 40{sup o}C in a continuous stirring tank reactor. The influence of the initial concentrations of iodine, iodate, hydrogen peroxide, H{sup +} ions has been determined. The kinetics curves comprise two distinct chemical phases both for molecular iodine and for iodine+1. The relative importance of the two processes is connected to the initial concentrations of [I{sub 2}], [IO{sub 3}{sup -}], [H{sub 2}O{sub 2}] and [H{sup +}]. A rate law has been determined for the two steps for molecular iodine. (author) figs., tabs., 22 refs.

The kinetic study of oxidation of iodine by hydrogen peroxide

International Nuclear Information System (INIS)

Cantrel, L.; Chopin, J.

1996-01-01

Iodine chemistry is one of the most important subjects of research in the field of reactor safety because this element can form volatile species which represent a biological hazard for environment. As the iodine and the peroxide are both present in the sump of the containment in the event of a severe accident on a light water nuclear reactor, it can be important to improve the knowledge on the reaction of oxidation of iodine by hydrogen peroxide. The kinetics of iodine by hydrogen peroxide has been studied in acid solution using two different analytical methods. The first is a UV/Vis spectrophotometer which records the transmitted intensity at 460 nm as a function of time to follow the decrease of iodine concentration, the second is an amperometric method which permits to record the increase of iodine+1 with time thanks to the current of reduction of iodine+1 to molecular iodine. The iodine was generated by Dushman reaction and the series of investigations were made at 40 o C in a continuous stirring tank reactor. The influence of the initial concentrations of iodine, iodate, hydrogen peroxide, H + ions has been determined. The kinetics curves comprise two distinct chemical phases both for molecular iodine and for iodine+1. The relative importance of the two processes is connected to the initial concentrations of [I 2 ], [IO 3 - ], [H 2 O 2 ] and [H + ]. A rate law has been determined for the two steps for molecular iodine. (author) figs., tabs., 22 refs

Iodine behaviour in PWR accidents leading to severe core damage

International Nuclear Information System (INIS)

Lucas, M.; Devillers, C.; Fermandjian, J.; Manesse, D.

1982-09-01

This paper deals with the iodine partition coefficient between the water at the bottom of the reactor building and the atmosphere above it. Molecular iodine is considered as a potential contributor to the airborne activity inside the reactor building. The concentration of molecular iodine in the containment atmosphere will depend, on one hand, upon mechanisms which generate that species and, on the other hand, upon the kinetics of chemical reactions which consume that species. Experiments have therefore been performed on the two following items: - molecular iodine formation through ν radiation from cesium iodide aerosols (droplets) in the reactor containment building, for doses ranging between 1.2 and 8 MRad (12 and 80 kSv), with solutions of various pH's and at different temperatures, - rate of hypoiodous acid disproportionation into iodate and iodide influencing further behavior of molecular iodine

Radioanalytical studies of iodine behaviour in the environment

International Nuclear Information System (INIS)

Evans, G.J.; Hammad, K.A.

1995-01-01

The behaviour of iodine in the environment is of interest both in relation to radioecology and human nutrition. Radiochemical techniques were used to evaluate various aspects of the behaviour of iodine in the environment. The natural iodine content of plant, water and soil samples collected from three sites was determined using preconcentration neutron activation analysis (PNAA). The effect of initial chemical speciation on the distribution of iodine between various soils, sediments and waters was evaluated using I-131 tracer. Iodide was found to adsorb more extensively than iodate, although four most of the solid/water systems examined, a substantial portion of the iodate was slowly reduced to iodide. Experiments involving gamma irradiation suggest that much of the sorption of iodide and reduction of iodate involved microbial processes. Distribution coefficients measured using I-131 were comparable with values based on the natural I-127 content. (author) 18 refs.; 5 tabs

Prospects of the high power iodine laser

International Nuclear Information System (INIS)

Hohla, K.; Brederlow, G.; Fill, E.; Volk, R.; Witte, K.J.

1976-09-01

The characteristic properties of the iodine laser (gaseous laser substance, photolytic pump mechanism, variable stimulated emission cross-section) made it possible in a relatively short time to generate ns pulses in the kJ range. The Asterix II and III iodine laser systems at IPP are working successfully, and the question arises what prospects are afforded for further iodine laser development. What are the problems that have to be clarified in order to build 10 or 100 kJ systems for laser fusion experiments. According to our experience these can be classified as follows: 1) Short pulse generation and contrast ratio, 2) pulse shaping in a high-gain laser and amplification in the coherent time range, 3) non-linear properties at high intensities, 4) scalable pumping schemes and chemical processes. (orig./WL) [de

Physics and engineering of singlet delta oxygen production in low-temperature plasma

International Nuclear Information System (INIS)

Ionin, A A; Kochetov, I V; Napartovich, A P; Yuryshev, N N

2007-01-01

An overview is presented of experimental and theoretical research in the field of physics and engineering of singlet delta oxygen (SDO) production in low-temperature plasma of various electric discharges. Attention is paid mainly to the SDO production with SDO yield adequate for the development of an electric discharge oxygen-iodine laser (DOIL). The review comprises a historical sketch describing the main experimental results on SDO physics in low-temperature plasma obtained since the first detection of SDO in electric discharge in the 1950s and the first attempt to launch a DOIL in the 1970s up to the mid-1980s when several research groups started their activity aimed at DOIL development, stimulated by success in the development of a chemical oxygen-iodine laser (COIL). A detailed analysis of theoretical and experimental research on SDO production in electric discharge from the mid-1980s to the present, when the first DOIL has been launched, is given. Different kinetic models of oxygen low-temperature plasma are compared with the model developed by the authors. The latter comprises electron kinetics based on the accompanying solution of the electron Boltzmann equation, plasma chemistry including reactions of excited molecules and numerous ion-molecular reactions, thermal energy balance and electric circuit equation. The experimental part of the overview is focused on the experimental methods of SDO detection including experiments on the measurements of the Einstein coefficient for SDO transition a 1 Δ g - X 3 Σ g - and experimental procedures of SDO production in self-sustained and non-self-sustained discharges and analysis of different plasma-chemical processes occurring in oxygen low-temperature plasma which brings limitation to the maximum SDO yield and to the lifetime of the SDO in an electric discharge and its afterglow. Quite recently obtained results on gain and output characteristics of DOIL and some projects aimed at the development of high-power DOIL

Adsorption and revaporisation studies on iodine oxide aerosols deposited on containment surface materials in LWR

Energy Technology Data Exchange (ETDEWEB)

Tietze, S.; Foreman, M.R.StJ.; Ekberg, C. [Chalmers Univ. of Technology, Goeteborg (Sweden); Kaerkelae, T.; Auvinen, A.; Tapper, U.; Lamminmaeki, S.; Jokiniemi, J. [VTT Technical Research Centre of Finland, Espoo (Finland)

2012-12-15

During a hypothetical severe nuclear accident, the radiation field will be very high in the nuclear reactor containment building. As a result gaseous radiolysis products will be formed. Elemental iodine can react in the gaseous phase with ozone to form solid iodine oxide aerosol particles (iodine oxide). Within the AIAS (Adsorption of Iodine oxide Aerosols on Surfaces) project the interactions of iodine oxide (IOx) aerosols with common containment surface materials were investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS, as well as Pt and Pd surfaces from hydrogen recombiners. Non-radioactive and {sup 131}I labelled iodine oxide aerosols were produced with the EXSI CONT facility from elemental iodine and ozone at VTT Technical Research Centre of Finland. The iodine oxide deposits were analysed with microscopic and spectroscopic measurement techniques to identify the kind of iodine oxide formed and if a chemical conversion on the different surface materials occurs. The revaporisation behaviour of the deposited iodine oxide aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 having a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The revaporisated {sup 131}I species from the surfaces were chemically tested for elemental iodine formation. The parameter dominating the degradation of the produced iodine oxide aerosols was humidity. Cu and Zn surfaces were found to react with iodine from the iodine oxide aerosols to form iodides, while no metal iodides were detected for Al and SS samples. Most of the iodine oxide aerosols are assumed to

On electrochemical sensor for determining elemental iodine in gas media

International Nuclear Information System (INIS)

Goffman, V.G.; Shajmerdinov, B.U.; Kotelkin, I.M.; Mikhajlova, A.M.; Dobrovol'skij, Yu.A.

1993-01-01

The possibility to use solid electrolyte cells of Ag, AgI/AgI/Au as sensors for determining concentration of element iodine in gaseous media was studied. Independent character of sensor parameters on oxygen content and radiation burden at different humidity was ascertained

Active molecular iodine photochemistry in the Arctic.

Science.gov (United States)

Raso, Angela R W; Custard, Kyle D; May, Nathaniel W; Tanner, David; Newburn, Matt K; Walker, Lawrence; Moore, Ronald J; Huey, L G; Alexander, Liz; Shepson, Paul B; Pratt, Kerri A

2017-09-19

During springtime, the Arctic atmospheric boundary layer undergoes frequent rapid depletions in ozone and gaseous elemental mercury due to reactions with halogen atoms, influencing atmospheric composition and pollutant fate. Although bromine chemistry has been shown to initiate ozone depletion events, and it has long been hypothesized that iodine chemistry may contribute, no previous measurements of molecular iodine (I 2 ) have been reported in the Arctic. Iodine chemistry also contributes to atmospheric new particle formation and therefore cloud properties and radiative forcing. Here we present Arctic atmospheric I 2 and snowpack iodide (I - ) measurements, which were conducted near Utqiaġvik, AK, in February 2014. Using chemical ionization mass spectrometry, I 2 was observed in the atmosphere at mole ratios of 0.3-1.0 ppt, and in the snowpack interstitial air at mole ratios up to 22 ppt under natural sunlit conditions and up to 35 ppt when the snowpack surface was artificially irradiated, suggesting a photochemical production mechanism. Further, snow meltwater I - measurements showed enrichments of up to ∼1,900 times above the seawater ratio of I - /Na + , consistent with iodine activation and recycling. Modeling shows that observed I 2 levels are able to significantly increase ozone depletion rates, while also producing iodine monoxide (IO) at levels recently observed in the Arctic. These results emphasize the significance of iodine chemistry and the role of snowpack photochemistry in Arctic atmospheric composition, and imply that I 2 is likely a dominant source of iodine atoms in the Arctic.

Active molecular iodine photochemistry in the Arctic

Energy Technology Data Exchange (ETDEWEB)

Raso, Angela R.; Custard, Kyle D.; May, Nathaniel W.; Tanner, David; Newburn, Matthew K.; Walker, Lawrence R.; Moore, Ronald J.; Huey, L. G.; Alexander, Lizabeth; Shepson, Paul B.; Pratt, Kerri A.

2017-09-05

During springtime, the Arctic atmospheric boundary layer undergoes frequent rapid depletions in ozone and gaseous elemental mercury due to reactions with halogen atoms, influencing atmospheric composition and pollutant fate. Although bromine chemistry has been shown to initiate ozone depletion events, and it has long been hypothesized that iodine chemistry may contribute, no previous measurements of molecular iodine (I₂) have been reported in the Arctic. Iodine chemistry also contributes to atmospheric new particle formation and therefore cloud properties and radiative forcing. Here we present Arctic atmospheric I2 and snowpack iodide (I-) measurements, which were conducted near Utqiagvik, AK, in February 2014. Using chemical ionization mass spectrometry, I2 was observed in the atmosphere at mole ratios of 0.3–1.0 ppt, and in the snowpack interstitial air at mole ratios up to 22 ppt under natural sunlit conditions and up to 35 ppt when the snowpack surface was artificially irradiated, suggesting a photochemical production mechanism. Further, snow meltwater I-measurements showed enrichments of up to ~1,900 times above the seawater ratio of I-/Na+, consistent with iodine activation and recycling. Modeling shows that observed I₂ levels are able to significantly increase ozone depletion rates, while also producing iodine monoxide (IO) at levels recently observed in the Arctic. These results emphasize the significance of iodine chemistry and the role of snowpack photochemistry in Arctic atmospheric composition, and imply that I₂ is likely a dominant source of iodine atoms in the Arctic.

Chemisorption of organic iodine compounds forming from fission isotopes of radioactive iodine

International Nuclear Information System (INIS)

Tot, G.; Galina, F.; Zel'd, E.

1977-01-01

Studied is ethyl iodine adsorption, labelled by iodine 131, on palladium black and on aluminium oxide activized by palladium. The desorption of adsorbed iodine in the temperature range of 20-600 deg C by the mass spectroscopy and thermal gravimetric methods was investigated. At the ethyl iodine and palladium interaction the bond between carbon and iodine in the ethyl iodine molecule breaks down and extracting iodine reacts with palladium, forming a stable compound at high temperatures. Desorption of adsorbed iodine is insignificant up to the temperatures of 250-300 deg C. Thus, sorbents, containing palladium, may be successfully applied for iodine absorption from the organic iodine compounds. These compounds spontaneously appear from the iodine fragment ratio isotopes during their interaction with some environmental organic impurities

Measurement of oxygen chemical diffusion in PuO2-x and analysis of oxygen diffusion in PuO2-x and (Pu,U)O2-x

International Nuclear Information System (INIS)

Kato, Masato; Uchida, Teppei; Sunaoshi, Takeo

2013-01-01

Oxygen chemical diffusion in PuO 2-x was investigated in the temperature range of 1473-1873 K by thermogravimetry as functions of oxygen-to-metal (O/M) ratios and temperatures. The oxygen chemical diffusion coefficients, D were determined assuming that the reduction curves were dominated by a diffusion process. The O/M ratio and Pu content dependence on the chemical diffusion coefficients were evaluated. The chemical diffusion coefficient had its minimum value at around O/M=1.98 and decreased with increasing Pu content in (U,Pu)O 2-x . The self-diffusion coefficients were evaluated. A model for describing the relationship among O/M ratio, oxygen chemical diffusion, and self-diffusion was proposed based on defect chemistry. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Chemical speciation of trace transition elements and iodine in freshwater at Rokkasho

International Nuclear Information System (INIS)

Takaku, Yuichi; Ohtsuka, Yoshihito; Hisamatsu, Shun'ichi

2007-01-01

Analytical methods for physicochemical speciation of radioactive and related materials, such as lanthanide, actinide and transition metals in environmental samples, were developed to elucidate behavior of radioactive materials in the environment. An inductively coupled plasma mass spectrometer (ICP-MS) was combined with a high-performance liquid chromatographer with a size exclusion (SEC) column or capillary electrophoresis apparatus (CE). Analytical methods using SEC-ICP-MS and CE-ICP-MS were developed for speciation of transition elements and iodine in environmental water samples in fiscal year 2004. The methods were applied to freshwater samples in Rokkasho; the results are reported here. Freshwater samples were collected from two lakes and three rivers surrounding the large-scale spent nuclear fuel reprocessing plant at Rokkasho. After samples were filtered with a membrane filter with 0.45 μm of pore size, large organic molecules were concentrated 200 times using an ultrafilter with a 10 kDa cutoff size. The concentrated solution was used for molecular size analyses using the SEC-ICP-MS technique. Molecular size chromatograms of all river and lake water samples showed two peaks of UV absorptions and concentrations of all transition elements analyzed: 30 kDa and >700 kDa peaks. Ratios of the transition element concentration in 30 kDa peak to that in both peaks varied greatly depending on the element and season of sample collection. Two valence states of inorganic iodine, I - and IO 3 - , were determined separately using the CE-ICP-MS system with a standard capillary column (150 μm inner φ, 75 cm length) with 30 kV as the extraction voltage. Buffer solution of 5 mM TRIS-HNO 3 (pH 3.0) was used for mobile phase. The method was applied to lake and river water samples collected at Rokkasho. Results indicated that the chemical form of inorganic iodine in all samples was IO 3 - . Additional lake water samples were collected from Lake O-ike-higashi-ko in the Juni

Altering iodine metabolism in the calf by feeding iodine-binding agents

International Nuclear Information System (INIS)

Miller, J.K.; Swanson, E.W.; Lyke, W.A.; Byrne, W.F.

1975-01-01

Effects of feeding cottonseed meal and anion-exchange resin on iodine absorption and excretion by calves were investigated. Each additional amount of resin fed from 0.3 to 3.5 g/kg body weight further increased fecal excretion from single oral iodine-131 and intravenous iodine-125 doses. By feeding 3 to 10 g cottonseed meal/kg body weight, excretion of oral iodine-131 given daily was increased 7 to 94 percent in feces and reduced as much as 35 percent in urine, but plasma iodine-131 was not changed. Introducing 1 g resin/kg body weight daily into the diet increased fecal iodine-131 excretion three to five times that with cottonseed meal alone and reduced both plasma and urinary iodine-131. The same amount of resin fed daily had similar effects on excretion of iodine-131 injected subcutaneously each day. Although iodine depletion by a highly efficient iodine binder (resin) in the gastrointestinal tract is probable, iodine binding by a natural feed constituent (cottonseed meal) was relatively inefficient. (U.S.)

Altering iodine metabolism in the calf by feeding iodine-binding agents

International Nuclear Information System (INIS)

Miller, J.K.; Swanson, E.W.; Lyke, W.A.; Byrne, W.F.

1975-01-01

Effects of feeding cottonseed meal and anion-exchange resin on iodine absorption and excretion by calves were investigated. Each additional amount of resin fed from 0.3 to 3.5 g/kg body weight further increased fecal excretion from single oral iodine-131 and intravenous iodine-125 doses. By feeding 3 to 10 g cottonseed meal/kg body weight, excretion of oral iodine-131 given daily was increased 7 to 94 percent in feces and reduced as much as 35 percent in urine, but plasma iodine-131 was not changed. Introducing 1 g resin/kg body weight daily into the diet increased fecal iodine-131 excretion three to five times that with cottonseed meal alone and reduced both plasma and urinary iodine-131. The same amount of resin fed daily had similar effects on excretion of iodine-131 injected subcutaneously each day. Although iodine depletion by a highly efficient iodine binder (resin) in the gastrointestinal tract is probable, iodine binding by a natural feed constituent (cottonseed meal) was relatively inefficient. (auth)

Atomic iodine laser

International Nuclear Information System (INIS)

Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

1978-05-01

The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

Conceptual design of SO3 decomposer for thermo-chemical iodine-sulfur process pilot plant

International Nuclear Information System (INIS)

Akihiro Kanagawa; Seiji Kasahara; Atsuhiko Terada; Shinji Kubo; Ryutaro Hino; Yoshiyuki Kawahara; Masaharu Watabe; Hiroshi Fukui; Kazuo Ishino; Toshio Takahashi

2005-01-01

Thermo-chemical water-splitting cycle is a method to make an effective use of the high temperature nuclear heat for hydrogen production. Japan Atomic Energy Research Institute (JAERI) has been conducting R and D on HTGR and also on thermo-chemical hydrogen production by using a thermo-chemical iodine-sulfur cycle (IS process). Based on the test results and know-how obtained through a bench-scale tests of hydrogen production of about 30 NL/hr, JAERI has a plan to construct a pilot test plant heated by high temperature helium gas, which has a hydrogen production performance of 30 Nm 3 /hr and will be operated under the high pressure up to 2 MPa. One of the key components of the pilot test plant is a SO 3 decomposer under high temperature conditions up to 850 degree C and high pressure up to 2 MPa. In this paper, a concept of the SO 3 decomposer for the pilot test plant fabricated with SiC ceramics, a corrosion-resistant material is investigated. Preliminary analyses on temperature and flow-rate distributions in the SO 3 decomposer and on thermal stress were carried out. A SO 3 decomposer model was experimentally manufactured. (authors)

O2(a1Δ) vibrational kinetics in oxygen-iodine laser

Science.gov (United States)

Torbin, A. P.; Pershin, A. A.; Heaven, M. C.; Azyazov, V. N.; Mebel, A. M.

2018-04-01

Kinetics of vibrationally-excited singlet oxygen O2(a1Δ,ν) in gas mixture O3/N2/CO2 was studied using a pulse laser technique. Molecules O2(a1Δ,ν) were produced by laser photolysis of ozone at 266 nm. The O3 molecules number density was followed using time-resolved absorption spectroscopy. It was found that an upper bound for the rate constant of chemical reaction O2(a1Δ,ν)+ O3 is about 10-15 cm3/s. The rate constants of O2(a1Δ,ν= 1, 2 and 3) quenching by CO2 are presented.

Recovery of iodine as iodine-125 from biological materials prior to assay

International Nuclear Information System (INIS)

Jones, G.B.; Belling, G.B.; Buckley, R.A.

1979-01-01

In biological tissues iodine is usually present as iodoamino acids or iodoproteins. The organic material must be oxidised and the iodine converted into iodate prior to the final spectrophotometric determination. At parts per billion (10 9 ) levels, recoveries of added iodine are difficult to measure precisely as iodine can easily be lost from the sample and added inorganic iodine may not be recovered in the same proportions as the naturally occurring iodine. Iodine-125 provides a much more sensitive, specific and accurate means of testing the recovery of nanogram amounts of iodine from biological tissues and it can be incorporated into tissues in the naturally occurring compounds. Plants can be grown in a solution culture containing iodine-125 and animals can be injected with iodine-125 to provide tissues where naturally occurring iodine compounds are labelled with radioactive iodine. These tissues can be used to examine the recovery of iodine after oven drying, freeze drying, alkali ashing and acid digestion of the samples. Experimental details are given for spinach, tobacco, oats, cauliflower and thyroid. Results are given and discussed. (author)

Influence of dietary iodine on drug-induced hypothyrodism in the rat.

Science.gov (United States)

Beyssen, M L; Lagorce, J F; Cledat, D; Buxeraud, J

1999-06-01

Several compounds of pharmaceutical importance from a variety of chemical families, for example chlorpromazine and clomipramine, have been found to form charge-transfer complexes with iodine. We have investigated the influence of dietary iodine on thyroid-gland dysfunction induced by clomipramine, chlorpromazine or 2-thiazoline-2-thiol. We suggest that iodine is partly diverted from its metabolic pathway by complexation with drugs, and so the urinary concentration of iodide is increased. Both chlorpromazine and clomipramine, at doses which do not inhibit thyroperoxidase, enhanced urinary iodine excretion when dietary iodine was restricted (3.944+/-0.96 microg/day for chlorpromazine-tested rats, 3.43+/-1.33 microg/day for clomipramine-tested rats, compared with 2.34+/-0.11 microg/day in control rats). Concurrently, these pharmaceutical compounds increased the level of free thyroid-stimulating hormone (TSH) in comparison with controls and induced histological modifications in, and enlargement of, the thyroid gland. We have demonstrated that drug-induced loss of iodine in the urine was associated with antithyroid action when iodine intake was limited.

Iodine leaflets in chapter D5 'Distribution of iodine pills'

International Nuclear Information System (INIS)

1981-01-01

Jodine leaflet A will be distributed together with iodine pills in a nuclear disaster. Iodine leaflet B is suitable for informing the public in advance. Iodine leaflet C informs physicians in a scientific way on the benefits and risk of iodine pills. (orig./HP) [de

Perchlorate, iodine supplements, iodized salt and breast milk iodine content

Energy Technology Data Exchange (ETDEWEB)

Kirk, Andrea B. [Department of Epidemiology, School of Public Health, University of North Texas Health Sciences Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107 (United States); Kroll, Martina; Dyke, Jason V.; Ohira, Shin-Ichi; Dias, Rukshan A.; Dasgupta, Purnendu K. [Department of Chemistry and Biochemistry, 700 Planetarium Place, University of Texas at Arlington, Arlington, TX 76019 (United States)

2012-03-15

This study was undertaken to determine if increasing maternal iodine intake through single dose tablets will decrease breast milk concentrations of the iodine-uptake inhibitor, perchlorate, through competitive inhibition. We also sought to determine if the timing of supplementation influences the fraction of iodine excreted in milk versus urine and to compare the effectiveness of iodized salt as a means of providing iodine to breastfed infants. Thirteen women who did not use supplements, seven of whom used iodized salt and six of whom used non-iodized salt, submitted four milk samples and a 24-h urine collection daily for three days. Women repeated the sampling protocol for three more days during which {approx} 150 {mu}g of iodine were taken in the evening and again for three days with morning supplementation. Samples were analyzed using isotope-dilution inductively-coupled plasma-mass spectrometry for iodine and isotope-dilution ion chromatography-tandem mass spectrometry for perchlorate. No statistically significant differences were observed in milk iodine or perchlorate concentrations during the two treatment periods. Estimated perchlorate intake was above the U.S. National Academy of Sciences suggested reference dose for most infants. Single daily dose iodine supplementation was not effective in decreasing milk perchlorate concentrations. Users of iodized salt had significantly higher iodine levels in milk than non-users. Iodized salt may be a more effective means of iodine supplementation than tablets. - Highlights: Black-Right-Pointing-Pointer Estimated infant exposures to perchlorate were, on a {mu}g/kg basis, {approx} 5 Multiplication-Sign higher than those of mothers. Black-Right-Pointing-Pointer Daily supplements are less effective than iodized salt in providing iodine to lactating women. Black-Right-Pointing-Pointer Low iodine and high perchlorate in milk may place infants at risk of iodine deficiency.

Iodine deficiency and iodine excess in Jiangsu Province, China

NARCIS (Netherlands)

Zhao, J.

2001-01-01

Keywords:
iodine deficiency, iodine excess, endemic goiter, drinking water, iodine intake, thyroid function, thyroid size, iodized salt, iodized oil, IQ, physical development, hearing capacity, epidemiology, meta-analysis, IDD, randomized trial, intervention, USA, Bangladesh,

An electrochemical sensor for determining elemental iodine in gas media

Energy Technology Data Exchange (ETDEWEB)

Goffman, V.G.; Shaimerdinov, B.U.; Kotelkin, I.M. [Institute of New Chemical Problems, Moscow (Russian Federation)] [and others

1993-12-01

The possibility of using solid-electrolyte Ag, AgI/AgI/Au cells as sensors for determining the concentration of elemental iodine in gas media is investigated. It is established that the sensor parameters are independent of oxygen content and radiation dose at different relative humidities.

Iodine in diet

Science.gov (United States)

Diet - iodine ... Many months of iodine deficiency in a person's diet may cause goiter or hypothyroidism . Without enough iodine, ... and older children. Getting enough iodine in the diet may prevent a form of physical and intellectual ...

Iodine and thyroid function

Directory of Open Access Journals (Sweden)

Hye Rim Chung

2014-03-01

Full Text Available Severe iodine deficiency causes hypothyroidism that results in impaired somatic growth and motor development in children. Mild and moderate iodine deficiencies cause multifocal autonomous growth of thyroid, which results in thyrotoxicosis. On the other hand, iodine excess is associated with the development of hypothyroidism and thyroid autoimmunity. In areas of iodine deficiency, a sudden increase in iodine intake is associated with transient hyperthyroidism. Recent studies demonstrated that long-term thyroid function of subjects who experienced both iodine deficiency and iodine excess during childhood tended to be abnormal despite optimization of their current iodine intake. Iodine status in the Korean Peninsula is very unique because people in the Republic of Korea have been shown to have predominantly excessive iodine levels, whereas the Democratic People's Republic of Korea is known to be an iodine-deficient area. Further research is warranted to verify the optimal ranges of iodine intake and to clarify the effects of iodine intake on thyroid disorders in the Korean Peninsula.

Iodine Deficiency

NARCIS (Netherlands)

Zimmermann, M.B.

2009-01-01

Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected.

RAIM-A model for iodine behavior in containment under severe accident condition

Energy Technology Data Exchange (ETDEWEB)

Kim, Han Chul; Cho, Yeong Hun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-12-15

Following a severe accident in a nuclear power plant, iodine is a major contributor to the potential health risks for the public. Because the amount of iodine released largely depends on its volatility, iodine's behavior in containment has been extensively studied in international programs such as International Source Term Programme-Experimental Program on Iodine Chemistry under Radiation (EPICUR), Organization for Economic Co-operation and Development (OECD)-Behaviour of Iodine Project, and OECD-Source Term Evaluation and Mitigation. Korea Institute of Nuclear Safety (KINS) has joined these programs and is developing a simplified, stand-alone iodine chemistry model, RAIM (Radio-Active Iodine chemistry Model), based on the IMOD methodology and other previous studies. This model deals with chemical reactions associated with the formation and destruction of iodine species and surface reactions in the containment atmosphere and the sump in a simple manner. RAIM was applied to a simulation of four EPICUR tests and one Radioiodine Test Facility test, which were carried out in aqueous or gaseous phases. After analysis, the results show a trend of underestimation of organic and molecular iodine for the gas-phase experiments, the opposite of that for the aqueous-phase ones, whereas the total amount of volatile iodine species agrees well between the experiment and the analysis result.

Povidone-Iodine-Based Polymeric Nanoparticles for Antibacterial Applications.

Science.gov (United States)

Gao, Tianyi; Fan, Hongbo; Wang, Xinjie; Gao, Yangyang; Liu, Wenxin; Chen, Wanjun; Dong, Alideertu; Wang, Yan-Jie

2017-08-09

As microbial contamination is becoming more and more serious, antibacterial agents play an important role in preventing and removing bacterial pathogens from microbial pollution in our daily life. To solve the issues with water solubility and antibacterial stability of PVP-I 2 (povidone-iodine) as a strong antibacterial agent, we successfully obtain hydrophobic povidone-iodine nanoparticles (povidone-iodine NPs) by a two-step method related to the advantage of nanotechnology. First, the synthesis of poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate) nanoparticles, i.e., P(NVP-MMA) NPs, was controlled by tuning a feed ratio of NVP to MMA. Then, the products P(NVP-MMA) NPs were allowed to undergo a complexation reaction with iodine, resulting in the formation of a water-insoluble antibacterial material, povidone-iodine NPs. It is found that the feed ratio of NVP to MMA has an active effect on morphology, chemical composition, molecular weight, and hydrophilic-hydrophobic properties of the P(NVP-MMA) copolymer after some technologies, such as SEM, DLS, elemental analysis, 1 H NMR, GPC, and the contact angle test, were used in the characterizations. The antibacterial property of povidone-iodine NPs was investigated by using Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa) as model bacteria with the colony count method. Interestingly, three products, such as glue, ink, and dye, after the incorporation of povidone-iodine NPs, show significant antibacterial properties. It is believed that, with the advantage of nanoscale morphology, the final povidone-iodine NPs should have great potential for utilization in various fields where antifouling and antibacterial properties are highly required.

Iodine immobilization in apatites

International Nuclear Information System (INIS)

Audubert, F.; Lartigue, J.E.

2000-01-01

In the context of a scientific program on long-lived radionuclide conditioning, a matrix for iodine 129 immobilization has been studied. A lead vanado-phosphate apatite was prepared from the melt of lead vanado-phosphate Pb 3 (VO 4 ) 1.6 (PO 4 ) 0.4 and lead iodide PbI 2 in stoichiometric proportions by calcination at 700 deg. C during 3 hours. Natural sintering of this apatite is not possible because the product decomposition occurs at 400 deg. C. Reactive sintering is the solution. The principle depends on the coating of lead iodide with lead vanado-phosphate. Lead vanado-phosphate coating is used as iodo-apatite reactant and as dense covering to confine iodine during synthesis. So the best condition to immobilize iodine during iodo-apatite synthesis is a reactive sintering at 700 deg. C under 25 MPa. We obtained an iodo-apatite surrounded with dense lead vanadate. Leaching behaviour of the matrix synthesized by solid-solid reaction is under progress in order to determine chemical durability, basic mechanisms of the iodo-apatite alteration and kinetic rate law. Iodo-apatite dissolution rates were pH and temperature dependent. We obtained a rate of 2.5 10 -3 g.m -2 .d -1 at 90 deg. C in initially de-ionised water. (authors)

Iodine Tagging Velocimetry in a Mach 10 Wake

Science.gov (United States)

Balla, Robert Jeffrey

2013-01-01

A variation on molecular tagging velocimetry (MTV) [1] designated iodine tagging velocimetry (ITV) is demonstrated. Molecular iodine is tagged by two-photon absorption using an Argon Fluoride (ArF) excimer laser. A single camera measures fluid displacement using atomic iodine emission at 206 nm. Two examples ofMTVfor cold-flowmeasurements areN2OMTV [2] and Femtosecond Laser Electronic Excitation Tagging [3]. These, like most MTV methods, are designed for atmospheric pressure applications. Neither can be implemented at the low pressures (0.1- 1 Torr) in typical hypersonic wakes. Of all the single-laser/singlecamera MTV approaches, only Nitric-Oxide Planar Laser Induced Fluorescence-based MTV [4] has been successfully demonstrated in a Mach 10 wake. Oxygen quenching limits transit times to 500 ns and accuracy to typically 30%. The present note describes the photophysics of the ITV method. Off-body velocimetry along a line is demonstrated in the aerothermodynamically important and experimentally challenging region of a hypersonic low-pressure near-wake in a Mach 10 air wind tunnel. Transit times up to 10 µs are demonstrated with conservative errors of 10%.

Experimental study on iodine chemistry (EXSI) - Containment experiments with elemental iodine

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland)); Holm, J.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Glaenneskog, H. (Vattenfall Power Consultant (Sweden))

2009-10-15

The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. Oxidation of iodine in gas phase has been one of the greatest remaining uncertainties in iodine behaviour during a severe accident. In this study the possible formation of iodine oxide aerosol due to radiolytic oxidation of gaseous iodine is experimentally tested and the reaction products are analysed. The experimental facility applied in this study is based on the sampling system built at VTT for ISTP program project CHIP conducted IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. The results from the experiments show an extensive particle formation when ozone and gaseous iodine react with each other. The formed particles were collected on filters, while gaseous iodine was trapped into bubbles. The particles were iodine oxides and the size of particles was approximately 100 nm. The transport of gaseous iodine through the facility decreased when both gaseous iodine and ozone were fed together into facility. Experimental study on radiolytic oxidation of iodine was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. (author)

Experimental study on iodine chemistry (EXSI) - Containment experiments with elemental iodine

International Nuclear Information System (INIS)

Kaerkelae, T.; Auvinen, A.; Holm, J.; Ekberg, C.; Glaenneskog, H.

2009-10-01

The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. Oxidation of iodine in gas phase has been one of the greatest remaining uncertainties in iodine behaviour during a severe accident. In this study the possible formation of iodine oxide aerosol due to radiolytic oxidation of gaseous iodine is experimentally tested and the reaction products are analysed. The experimental facility applied in this study is based on the sampling system built at VTT for ISTP program project CHIP conducted IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. The results from the experiments show an extensive particle formation when ozone and gaseous iodine react with each other. The formed particles were collected on filters, while gaseous iodine was trapped into bubbles. The particles were iodine oxides and the size of particles was approximately 100 nm. The transport of gaseous iodine through the facility decreased when both gaseous iodine and ozone were fed together into facility. Experimental study on radiolytic oxidation of iodine was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. (author)

Chemical complexity in the winds of the oxygen-rich supergiant star VY Canis Majoris

Science.gov (United States)

Ziurys, L. M.; Milam, S. N.; Apponi, A. J.; Woolf, N. J.

2007-06-01

The interstellar medium is enriched primarily by matter ejected from old, evolved stars. The outflows from these stars create spherical envelopes, which foster gas-phase chemistry. The chemical complexity in circumstellar shells was originally thought to be dominated by the elemental carbon to oxygen ratio. Observations have suggested that envelopes with more carbon than oxygen have a significantly greater abundance of molecules than their oxygen-rich analogues. Here we report observations of molecules in the oxygen-rich shell of the red supergiant star VY Canis Majoris (VY CMa). A variety of unexpected chemical compounds have been identified, including NaCl, PN, HNC and HCO+. From the spectral line profiles, the molecules can be distinguished as arising from three distinct kinematic regions: a spherical outflow, a tightly collimated, blue-shifted expansion, and a directed, red-shifted flow. Certain species (SiO, PN and NaCl) exclusively trace the spherical flow, whereas HNC and sulphur-bearing molecules (amongst others) are selectively created in the two expansions, perhaps arising from shock waves. CO, HCN, CS and HCO+ exist in all three components. Despite the oxygen-rich environment, HCN seems to be as abundant as CO. These results suggest that oxygen-rich shells may be as chemically diverse as their carbon counterparts.

Primary circuit iodine model addition to IMPAIR-3

Energy Technology Data Exchange (ETDEWEB)

Osetek, D J; Louie, D L.Y. [Los Alamos Technical Associates, Inc., Albuquerque, NM (United States); Guntay, S; Cripps, R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1996-12-01

As part of a continuing effort to provide the U.S. Department of Energy (DOE) Advanced Reactor Severe Accident Program (ARSAP) with complete iodine analysis capability, a task was undertaken to expand the modeling of IMPAIR-3, an iodine chemistry code. The expanded code will enable the DOE to include detailed iodine behavior in the assessment of severe accident source terms used in the licensing of U.S. Advanced Light Water Reactors (ALWRs). IMPAIR-3 was developed at the Paul Scherrer Institute (PSI), Switzerland, and has been used by ARSAP for the past two years to analyze containment iodine chemistry for ALWR source term analyses. IMPAIR-3 is primarily a containment code but the iodine chemistry inside the primary circuit (the Reactor Coolant System or RCS) may influence the iodine species released into the the containment; therefore, a RCS iodine chemistry model must be implemented in IMPAIR-3 to ensure thorough source term analysis. The ARSAP source term team and the PSI IMPAIR-3 developers are working together to accomplish this task. This cooperation is divided into two phases. Phase I, taking place in 1996, involves developing a stand-alone RCS iodine chemistry program called IMPRCS (IMPAIR -Reactor Coolant System). This program models a number of the chemical and physical processes of iodine that are thought to be important at conditions of high temperature and pressure in the RCS. In Phase II, which is tentatively scheduled for 1997, IMPRCS will be implemented as a subroutine in IMPAIR-3. To ensure an efficient calculation, an interface/tracking system will be developed to control the use of the RCS model from the containment model. These two models will be interfaced in such a way that once the iodine is released from the RCS, it will no longer be tracked by the RCS model but will be tracked by the containment model. All RCS thermal-hydraulic parameters will be provided by other codes. (author) figs., tabs., refs.

Iodine intake in Ireland

International Nuclear Information System (INIS)

Smith, P.P.A.; Hetherton, A.M.; O'Carroll, D.; Smith, D.F.; O'Halloran, M.J.; O'Donovan, D.K.

1988-01-01

A study of urinary iodine excretion and thyroid gland uptake of radioactive iodine 131 I was undertaken in the Dublin area with a view to providing data on the current iodine status in Ireland. A mean urinary iodine excretion of 118±82μg/gram creatinine (Median 96) obtained from 821 subjects attending general hospital outpatient clinics in the Dublin area in 1987, while excluding severe iodine deficiency in this particular cohort, obscured the fact that 250 (30%) had iodine excretion values ≤70 μ/g creatinine, a value approximating to the minimum daily iodine requirement. The results provide sufficient evidence of sporadic iodine deficiency to justify a more widespread study of the iodine status of the Irish population with a view to making recommendations on the possible need for iodine prophylaxis

Iodination of phenol

International Nuclear Information System (INIS)

Christiansen, J.V.; Feldthus, A.; Carlsen, L.

1990-01-01

Phenol is iodinated in aqueous solution at pH 5 (acetate buffer) by elemental iodine or, if the iodine is present as iodide, enzymatically controlled by peroxidases. Generally mono-, di- and triiodophenols are obtained, the overall product composition being virtually identical for the two iodination modes. However, there is a tendency to a higher para to ortho ratio for the enzymatically controlled reaction. The mutual ratios of the single iodophenols depends on the initial concentration ratio between phenol and the iodinating species. The first step in the iodination leads preferentially to substitution in the ortho position rather than in the para position in contract to e.g. the corresponding bromination. The relative rates of the competive reactions in the combined iodination scheme has been derived. (author) 2 tabs., 3 ills., 15 refs

The treatment of iodine and chlorine chemistry in the risk assessment of deep radioactive waste disposal

International Nuclear Information System (INIS)

Jones, Michael A.

1992-01-01

The predicted contribution from 129 I, 131 I and 36 Cl to the radiological risk from a radioactive waste repository may be enhanced by the assumption of limited retardation in the near field and geosphere. However, migration of these radionuclides may be affected by their chemical speciation and retarded by a range of sorption processes. The chemical behaviour of iodine and chlorine is determined emphasizing i) aqueous speciations, ii) sorption onto inorganic substrates, and iii) the role of organic matter and microbes. Recommendations to enhance the methodology include i) consideration of aqueous speciation of iodine, both metal and organic complexes, ii) mechanistic simulation of iodine sorption by ion exchange and electrostatic/covalent adsorption, iii) simulation of enzymatically enhanced sorption of iodine and chlorine onto organic substrates, iv) enhancement of HMIP K d databases to include iodine and chlorine data for the geosphere and biosphere. A well defined programme of additional data collection, modelling studies and experimental investigations is recommended to achieve these enhancements. (author)

Metal ferrite oxygen carriers for chemical looping combustion of solid fuels

Science.gov (United States)

Siriwardane, Ranjani V.; Fan, Yueying

2017-01-31

The disclosure provides a metal ferrite oxygen carrier for the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The metal ferrite oxygen carrier comprises MFe.sub.xO.sub.y on an inert support, where MFe.sub.xO.sub.y is a chemical composition and M is one of Mg, Ca, Sr, Ba, Co, Mn, and combinations thereof. For example, MFe.sub.xO.sub.y may be one of MgFe.sub.2O.sub.4, CaFe.sub.2O.sub.4, SrFe.sub.2O.sub.4, BaFe.sub.2O.sub.4, CoFe.sub.2O.sub.4, MnFeO.sub.3, and combinations thereof. The MFe.sub.xO.sub.y is supported on an inert support. The inert support disperses the MFe.sub.xO.sub.y oxides to avoid agglomeration and improve performance stability. In an embodiment, the inert support comprises from about 5 wt. % to about 60 wt. % of the metal ferrite oxygen carrier and the MFe.sub.xO.sub.y comprises at least 30 wt. % of the metal ferrite oxygen carrier. The metal ferrite oxygen carriers disclosed display improved reduction rates over Fe.sub.2O.sub.3, and improved oxidation rates over CuO.

A tight-binding potential for the simulation of solid and liquid iodine

CERN Document Server

Kozlovskii, T

2003-01-01

In this work, we suggest an interatomic potential for iodine applicable to the simulation of the condensed phases of the halogen within the temperature and density range accessible to experiments. The potential includes an attractive term that is partitioned into directional chemical bonding with a many-particle character and a pairwise interaction. Despite its simplicity, the potential reproduces the crystal structure of solid iodine, the presence of atomic phases with increasing pressure, and the metallic or insulating character of the solid phases. Finally, we present preliminary simulation results for fluid iodine.

A review of iodine chemistry under severe accident conditions

International Nuclear Information System (INIS)

Clough, P.M.; Starkie, H.C.; Wren, D.J.; Paquette, J.; Wren, J.C.

1987-01-01

This report reviews the progress that has been made in establishing a basic understanding of the factors which will determine the behaviour of iodine during postulated accidents in water-cooled reactors. The topics considered are thermal reactions, radiolytic reactions, impurity effects, organic iodide formation, integral models and tests and volatility control. There have been substantial gains in a number of areas, most notably in the kinetics and thermodynamics databases for thermal and radiolytic reactions of inorganic iodine in solution. However, there remains a limited understanding of the mechanisms controlling the formation of organic iodides and a need for integral tests of iodine behaviour in complex, 'dirty' systems to provide data for the validation of chemical models which are undergoing development. 81 refs

Iodine and Pregnancy

OpenAIRE

Yarrington, Christina; Pearce, Elizabeth N.

2011-01-01

Iodine is a necessary element for the production of thyroid hormone. We will review the impact of dietary iodine status on thyroid function in pregnancy. We will discuss iodine metabolism, homeostasis, and nutritional recommendations for pregnancy. We will also discuss the possible effects of environmental contaminants on iodine utilization in pregnant women.

Syngas Generation from Methane Using a Chemical-Looping Concept: A Review of Oxygen Carriers

Directory of Open Access Journals (Sweden)

Kongzhai Li

2013-01-01

Full Text Available Conversion of methane to syngas using a chemical-looping concept is a novel method for syngas generation. This process is based on the transfer of gaseous oxygen source to fuel (e.g., methane by means of a cycling process using solid oxides as oxygen carriers to avoid direct contact between fuel and gaseous oxygen. Syngas is produced through the gas-solid reaction between methane and solid oxides (oxygen carriers, and then the reduced oxygen carriers can be regenerated by a gaseous oxidant, such as air or water. The oxygen carrier is recycled between the two steps, and the syngas with a ratio of H2/CO = 2.0 can be obtained successively. Air is used instead of pure oxygen allowing considerable cost savings, and the separation of fuel from the gaseous oxidant avoids the risk of explosion and the dilution of product gas with nitrogen. The design and elaboration of suitable oxygen carriers is a key issue to optimize this method. As one of the most interesting oxygen storage materials, ceria-based and perovskite oxides were paid much attention for this process. This paper briefly introduced the recent research progresses on the oxygen carriers used in the chemical-looping selective oxidation of methane (CLSOM to syngas.

Iodine

Science.gov (United States)

... Health Information Supplement Fact Sheets Frequently Asked Questions Making Decisions What you Need To Know About Supplements Dietary ... mild iodine deficiency and of iodine supplements on cognitive ... breasts. It mainly affects women of reproductive age but can also occur ...

Low-level seaweed supplementation improves iodine status in iodine-insufficient women.

Science.gov (United States)

Combet, Emilie; Ma, Zheng Feei; Cousins, Frances; Thompson, Brett; Lean, Michael E J

2014-09-14

Iodine insufficiency is now a prominent issue in the UK and other European countries due to low intakes of dairy products and seafood (especially where iodine fortification is not in place). In the present study, we tested a commercially available encapsulated edible seaweed (Napiers Hebridean Seagreens® Ascophyllum nodosum species) for its acceptability to consumers and iodine bioavailability and investigated the impact of a 2-week daily seaweed supplementation on iodine concentrations and thyroid function. Healthy non-pregnant women of childbearing age, self-reporting low dairy product and seafood consumption, with no history of thyroid or gastrointestinal disease were recruited. Seaweed iodine (712 μg, in 1 g seaweed) was modestly bioavailable at 33 (interquartile range (IQR) 28-46) % of the ingested iodine dose compared with 59 (IQR 46-74) % of iodine from the KI supplement (n 22). After supplement ingestion (2 weeks, 0·5 g seaweed daily, n 42), urinary iodine excretion increased from 78 (IQR 39-114) to 140 (IQR 103-195) μg/l (Pseaweed was palatable and acceptable to consumers as a whole food or as a food ingredient and effective as a source of iodine in an iodine-insufficient population. In conclusion, seaweed inclusion in staple foods would serve as an alternative to fortification of salt or other foods with KI.

Sodium, Iodine and Bromine in Polar Ice Cores

DEFF Research Database (Denmark)

Maffezzoli, Niccolo

Abstract: This research focuses on sodium, bromine and iodine in polar ice cores, with the aim of reviewing and advancing their current understanding with additional measurements and records, and investigating the connections of these tracers with sea ice and their feasibility as sea ice indicators...... with a description of the main analytic al techniques used to measure ionic and elemental species in ice cores. Chapter 4 introduces sodium, bromine and iodine with a theoretical perspective and a particular focus on their connections with sea ice. Some of the physical and chemical properties that are believed...... back trajectory analyses of the past 17 years. The results identify the aerosol source area influencing the Renland ice cap, a result necessary for the interpretation of impurity records obtained from the ice core. Chapter 6 reviews the published ice/snow measurements of bromine and iodine at polar...

Experimental and modelling studies of iodine oxide formation and aerosol behaviour relevant to nuclear reactor accidents

International Nuclear Information System (INIS)

Dickinson, S.; Auvinen, A.; Ammar, Y.; Bosland, L.; Clément, B.; Funke, F.; Glowa, G.; Kärkelä, T.; Powers, D.A.; Tietze, S.; Weber, G.; Zhang, S.

2014-01-01

Highlights: • Radiolytic reactions can influence iodine volatility following a nuclear accident. • Kinetic models have been developed based on atmospheric chemistry studies. • Properties of iodine oxide aerosols produced by radiation have been measured. • Decomposition of iodine oxides by the action of heat or radiation has been observed. - Abstract: Plant assessments have shown that iodine contributes significantly to the source term for a range of accident scenarios. Iodine has a complex chemistry that determines its chemical form and, consequently, its volatility in the containment. If volatile iodine species are formed by reactions in the containment, they will be subject to radiolytic reactions in the atmosphere, resulting in the conversion of the gaseous species into involatile iodine oxides, which may deposit on surfaces or re-dissolve in water pools. The concentration of airborne iodine in the containment will, therefore, be determined by the balance between the reactions contributing to the formation and destruction of volatile species, as well as by the physico-chemical properties of the iodine oxide aerosols which will influence their longevity in the atmosphere. This paper summarises the work that has been done in the framework of the EC SARNET (Severe Accident Research Network) to develop a greater understanding of the reactions of gaseous iodine species in irradiated air/steam atmospheres, and the nature and behaviour of the reaction products. This work has mainly been focussed on investigating the nature and behaviour of iodine oxide aerosols, but earlier work by members of the SARNET group on gaseous reaction rates is also discussed to place the more recent work into context

A Spectroscopic Method for Determining Free Iodine in Iodinated Fatty-Acid Esters

Science.gov (United States)

Klyubin, V. V.; Klyubina, K. A.; Makovetskaya, K. N.

2018-01-01

It is shown that the concentration of free iodine in samples of iodinated fatty-acid esters can be measured using the electronic absorption spectra of their solutions in ethanol. The method proposed is rather simple in use and highly sensitive, allowing detection of presence of less than 10 ppm of free iodine in iodinated compounds. It is shown using the example of Lipiodol that this makes it possible to easily detect small amounts of free iodine in samples containing bound iodine in concentrations down to 40 wt %.

Raim – A model for iodine behavior in containment under severe accident condition

Directory of Open Access Journals (Sweden)

Han-Chul Kim

2015-12-01

Full Text Available Following a severe accident in a nuclear power plant, iodine is a major contributor to the potential health risks for the public. Because the amount of iodine released largely depends on its volatility, iodine's behavior in containment has been extensively studied in international programs such as International Source Term Programme-Experimental Program on Iodine Chemistry under Radiation (EPICUR, Organization for Economic Co-operation and Development (OECD-Behaviour of Iodine Project, and OECD-Source Term Evaluation and Mitigation. Korea Institute of Nuclear Safety (KINS has joined these programs and is developing a simplified, stand-alone iodine chemistry model, RAIM (Radio-Active Iodine chemistry Model, based on the IMOD methodology and other previous studies. This model deals with chemical reactions associated with the formation and destruction of iodine species and surface reactions in the containment atmosphere and the sump in a simple manner. RAIM was applied to a simulation of four EPICUR tests and one Radioiodine Test Facility test, which were carried out in aqueous or gaseous phases. After analysis, the results show a trend of underestimation of organic and molecular iodine for the gas-phase experiments, the opposite of that for the aqueous-phase ones, whereas the total amount of volatile iodine species agrees well between the experiment and the analysis result.

Combined DFT and XPS investigation of iodine anions adsorption on the sulfur terminated (001) chalcopyrite surface

Energy Technology Data Exchange (ETDEWEB)

Li, Kui, E-mail: likui9606@stu.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Zhao, Yaolin, E-mail: zhaoyaolin@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, Peng, E-mail: zp32@qq.com [Sino Shaanxi Nuclear Industry Group, Xi’an 710100 (China); He, Chaohui, E-mail: hechaohui@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Deng, Jia, E-mail: djkokocase@stu.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Ding, Shujiang, E-mail: dingsj@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Shi, Weiqun, E-mail: shiwq@ihep.ac.cn [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2016-12-30

Highlights: • Metal surface sites of (001)-S surface of chalcopyrite show significant chemical affinity to iodide and iodate. • The energetically favorable active site is copper for iodide adsorption and iron for iodate adsorption, respectively. • Iodate undergoes a dissociative adsorption on the copper site of chalcopyrite surface. - Abstract: The adsorption of iodine anions (iodide and iodate) on the sulfur terminated (001) chalcopyrite surface has been systematically investigated combining first-principles calculations based on density functional theory (DFT) with X-ray photoelectron spectroscopy (XPS) measurements. Based on the total energy calculations and geometric optimization, the thermodynamically preferred site was copper atom for iodide adsorption and iron atom for iodate adsorption, respectively. In the case of Cu site mode, the iodate underwent a dissociative adsorption, where one I−O bond of iodate ion was broken and the dissociative oxygen atom adsorbed on the adjacent sulphur site. Projected density of states (PDOS) analysis further clarified the interaction mechanism between active sites of chalcopyrite surface and adsorbates. In addition, full-range XPS spectra qualitatively revealed the presence of iodine on chalcopyrite surface. High resolution XPS spectra of the I 3d peaks after adsorption verified the chemical environment of iodine. The binding energies of 618.8 eV and 623.5 eV for I 3d{sub 5/2} peaks unveiled that the adsorption of iodide and iodate ions on copper-iron sulfide minerals was the result of formation of low solubility metal iodides precipitate. Also two I 3d peaks with low intensity around 618 eV and 630 eV might be related to the inorganic reduction of iodate to iodide by reducing S{sup 2−} ion of chalcopyrite.

[Assessment of dietary iodine intake of population in non-high-iodine areas in China].

Science.gov (United States)

Song, Xiaoyu; Li, Fengqin; Liu, Zhaoping; He, Yuna; Sui, Haixia; Mao, Weifeng; Liu, Sana; Yan, Weixing; Li, Ning; Chen, Junshi

2011-03-01

To assess the potential risk of dietary iodine insufficiency of population in non-high-iodine areas (water iodine China. The dietary iodine intake of 13 age-sex population groups were estimated by combining the data of iodine intake from food, table salt and drinking water. Two conditions were considered: consuming iodized salt or non-iodized salt. The data of food and table salt consumption were derived from the Chinese National Nutrition and Health Survey in 2002. Water consumption was calculated as the recommended water intake. Iodine contents of food, table salt and water were calculated from China Food Composition Table and iodine surveillance data. Under the condition of consuming iodized salt, the average iodine intake of all population groups was higher than the Recommended Nutrient Intake (RNI), while the iodine intakes of individuals above Upper Limits (UL) and below RNI were 5.8% and 13.4% respectively, and the iodine intake of individuals lower than the Estimated Average Requirement (EAR) was 9.4% in adults above 18 years of age (including pregnant and lactating women). If non-iodized salt was consumed, the average iodine intake of most sex-age population groups was higher than RNI, but the iodine intake of 97.6% of individuals would be lower than RNI, while the iodine intake of 97.4% of adults would be lower than EAR. The contribution of iodine from table salt was much higher than that from drinking water and food in the condition of consuming iodized salt, while food was the predominant contributor of dietary iodine in the condition of consuming non-iodized salt. The health risk of iodine deficiency was higher than that of iodine excess in areas where water iodine was China, and the risk of iodine insufficiency was much higher if non-iodized salt was consumed. Iodized salt should be the main sources of dietary iodine intake for population in areas where water iodine was China.

An assessment of Raman spectroscopy to detect iodine deposited on thin oxide films formed on Type 316 stainless steel

International Nuclear Information System (INIS)

Allen, G.C.; Tyler, J.W.

1989-04-01

Iodine-131 is one of the most important volatile fission product elements with respect to radiobiological impact, and the characterisation of its chemical state and distribution on reactor surfaces is required for reactor safety assessments. To this end, duplicate samples of Type 316 (17%Cr/12%Ni) stainless steel oxidised in Co 2 /CH 3 I gas mixtures and previously characterised using X-ray photoelectron spectroscopy have been examined using Raman spectroscopy. The aim is to improve our understanding of the way in which iodine is distributed throughout the oxide scale and to identify its chemical state. In this report we present Raman spectra recorded from a series of stainless steel specimens together with spectra recorded from a number of standard iodine compounds. It is demonstrated that the technique is well suited as a fingerprint method of species identification, can differentiate between the chemical state of iodine as iodide and iodate and can analyse thin oxide films (5-50 nm). Identification of iodine deposits in these oxide films at concentrations of ≤1 At% was not achieved however, there being insufficient iodine present to distinguish any peaks present from the background signal. It is concluded that local concentrations of iodine in oxide inclusions of different composition/morphology on the steel surface does not occur to any extent. (author)

Insights into iodine behaviour and speciation in the Phébus primary circuit

International Nuclear Information System (INIS)

Girault, N.; Payot, F.

2013-01-01

Highlights: • Unexpectedly, gaseous iodine was transported in the circuit during some test periods. • The highest gaseous iodine fraction was measured in FPT3. • Several iodine vapours were evidenced in the hot leg, CsI being not predominant. • Equilibrium gas-phase chemistry do not explain the experimental iodine results. • Kinetic limitations in iodine reactions probably played a significant role. - Abstract: The Phébus FP integral test series studies a large spectrum of the phenomenology of severe accidents in water-cooled nuclear reactors. These tests represent a unique source of representative integral source term data, covering fuel rod degradation and behaviour of fission-products released via the coolant system into the containment. The present analysis concerns the behaviour of iodine in the test circuit representing the Reactor Coolant System (RCS) which reaches gas temperatures of nearly 1600 °C at the circuit entrance and descending to 150 °C before entry into the containment. The stake in the data analysis is a better understanding of iodine phenomenology in RCS. This is indeed all the more serious as iodine is one of the most radiological important fission products released from the fuel and may exist under highly volatile forms even within cold leg thermal– hydraulics conditions. Complex and coupled phenomena arise in the primary circuit during the tests as the temperature decreases (drops) from the inlet of the circuit to the outlet. These are respectively for the iodine vapours and aerosols: chemical transformation, condensation on walls/aerosols, homogeneous nucleation into aerosols and agglomeration, deposition by thermophoresis. Depending on the location in the primary circuit, a combination of these phenomena occurred simultaneously. The phenomenological behaviour of iodine in RCS will be appraised through the analyses of the iodine transport, retention, vapour speciation and gaseous occurrence in the Phébus FP primary circuit

Measurement of oxygen chemical diffusion in PuO{sub 2-x} and analysis of oxygen diffusion in PuO{sub 2-x} and (Pu,U)O{sub 2-x}

Energy Technology Data Exchange (ETDEWEB)

Kato, Masato; Uchida, Teppei [Advanced Nuclear System Research and Development Directorate, Japan Atomic Energy Agency, 4-33 Muramatsu, Tokai-mura, Ibaraki 319-1194 (Japan); Sunaoshi, Takeo [Inspection Development Company Ltd., 4-33 Muramatsu, Tokai-mura, Ibaraki 319-1194 (Japan)

2013-02-15

Oxygen chemical diffusion in PuO{sub 2-x} was investigated in the temperature range of 1473-1873 K by thermogravimetry as functions of oxygen-to-metal (O/M) ratios and temperatures. The oxygen chemical diffusion coefficients, D were determined assuming that the reduction curves were dominated by a diffusion process. The O/M ratio and Pu content dependence on the chemical diffusion coefficients were evaluated. The chemical diffusion coefficient had its minimum value at around O/M=1.98 and decreased with increasing Pu content in (U,Pu)O{sub 2-x}. The self-diffusion coefficients were evaluated. A model for describing the relationship among O/M ratio, oxygen chemical diffusion, and self-diffusion was proposed based on defect chemistry. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Highly efficient capture of iodine by Cu/MIL-101

Science.gov (United States)

Qi, Bingbing; Liu, Ying; Zheng, Tao; Gao, Qianhong; Yan, Xuewu; Jiao, Yan; Yang, Yi

2018-02-01

In order to improve the uptake capacity of MIL-101 for iodine, Cu nanoparticles doped MIL-101 were successfully synthesized through a facile method. The obtained Cu/MIL-101 was characterized by SEM, XRD, EDS, TEM, IR, TGA and BET to examine the chemical and thermal stabilities. The capture experiments for the adsorbents showed that the capture capacity of Cu/MIL-101 for volatile iodine is 342 wt%, which is higher than that of pure MIL-101. An I2 uptake of 342 wt% is the highest value reported among metal-organic frameworks. Furthermore, Cu/MIL-101 has a cycle ratio of 95% after three cycles and exhibits a better cyclicity than pure MIL-101. Meanwhile, Cu/MIL-101 shows an excellent reversible adsorption of iodine in solution.

Iodine intake in Denmark

International Nuclear Information System (INIS)

Pedersen, K.M.; Noehr, S.B.; Laurberg, P.

1997-01-01

Iodine deficiency with a high frequency of goitre and, in severely affected areas, cretinism is common in some areas of the world. In Denmark the iodine intake as evaluated by urinary iodine excretion has been at a stable low level for many years, except for the part of the population now taking iodine supplementation as part of vitamin/mineral preparations. The iodine intake is lowest in the western part to the country where an epidemiological study of elderly subjects has demonstrated a high frequency of goitre and hyperthyroidism in women. This supports the suggestion of a controlled moderate increase in iodine intake via an iodine supplementation program. (au) 40 refs

Transport of Iodine Species in the Terrestrial Environment

International Nuclear Information System (INIS)

Hu, Q; Moran, J E; Zhao, P

2003-01-01

The fate and transport of iodine in the environment is of interest because of the large production and release of 129 I from anthropogenic sources. 129 I has a long half-life (1.57 x 10 7 years) and exhibits complex geochemical behavior. The main source of 129 I in the environment is from nuclear fuel reprocessing facilities; about 2,600 kg from facilities in England and France. During 1944-1972, the Hanford Site in Washington state released about 260 kg 129 I. Iodine has a unique and complex chemistry in the environment, and its fate and transport in aqueous environments is dictated by its chemical speciation. In reducing environments, aqueous iodine usually occurs as the highly mobile iodide anion (I - ). Under more oxidizing conditions, iodine may be present as the more reactive iodate anion (IO 3 - ), which could lead to retarded transport through interaction with clays and organic matter. Co-existing iodine species (I - , IO 3 - , I 2 , and organoiodine compounds), in different proportions, has been reported in various terrestrial environments. However, there are conflicting reports regarding the environmental behavior of the different types of inorganic iodine and few publications on organic iodine compounds. This work examines the sorption and transport behavior of both inorganic and organic iodine species in geological samples from several complexes of the U.S. Department of Energy, where transport of radionuclides, including 129 I, may occur. Experiments on soils and sediments from the Savannah River Site in South Carolina, Oak Ridge Site in Tennessee, Hanford Site in Washington, Livermore Site 300 in California, and a surface soil from Santa Fe in New Mexico near Los Alamos were carried out. Samples from Savannah River Site and Livermore Site 300 are available from different depths. In addition, a surface soil of Wisconsin with a high amount of organic matter is utilized. This wide variety of sample types provides opportunities to examine the influence of

Measurements and Modelling of Reactive Iodine Oxides in the Coastal MBL

Science.gov (United States)

Najera, J. J.; Bloss, W. J.

2012-04-01

The release of iodine compounds into the marine atmosphere can affect a number of aspects of atmospheric composition: Iodine species can participate in catalytic ozone destruction cycles, which may be augmented by bromine species; reactions of iodine compounds can perturb the OH:HO2 and NO:NO2 ratios, heterogeneous loss of reservoir compounds such as HOI and INO3 can lead to removal of HOx and NOx, and higher iodine oxides can contribute to the formation and/or growth of aerosol particles. In this work, we focus upon understanding the effect of the spatial distribution of iodine emissions upon local HOx and NOx levels in the immediate vicinity of a coastal sites, using new observations to re-evaluate previous field campaign data. We present an analysis of results from a new instruments which measures point inorganic iodine species concentrations. The technique of resonance fluorescence (RF) is employed for the detection of iodine atoms, and the total photolabile iodine content. Measurements made at Mace Head, Ireland during July-August 2007 and May 2011 are presented. A detailed 1-dimensional photochemical box model is employed in a lagrangian sense to simulate the evolving chemical composition of an air column advected across the coastal margin. The model is compared with the observed iodine species, and then used to explore the transient response of the NOx and HOx families at the Mace Head site to heterogeneous iodine emissions: The transit time between the intertidal iodine emission zone and the shoreline site where previous measurements of HOx, NOx etc. have been made is insufficient for steady-state to become established, although this assumption has been used in earlier model studies of such data. Finally, we consider the limitations in our ability to quantify the impacts of iodine chemistry, which arise from uncertainties in the iodine kinetics and photochemistry - for example, what is the atmospheric lifetime of inorganic iodine ? - and explore their

Studies on the role of molybdenum on iodine transport in the RCS in nuclear severe accident conditions

International Nuclear Information System (INIS)

Grégoire, A.-C.; Kalilainen, J.; Cousin, F.; Mutelle, H.; Cantrel, L.; Auvinen, A.; Haste, T.; Sobanska, S.

2015-01-01

Highlights: • In oxidising conditions, Mo reacts with Cs and thus promotes gaseous iodine release. • In reducing conditions, CsI remains the dominant form for released iodine. • The nature of released iodine is well reproduced by the ASTEC code. - Abstract: The effect of molybdenum on iodine transport in the reactor coolant system (RCS) under PWR severe accident conditions was investigated in the framework of the EU SARNET project. Experiments were conducted at the VTT-Institute and at IRSN and simulations of the experimental results were performed with the ASTEC severe accident simulation code. As molybdenum affects caesium chemistry by formation of molybdates, it may have a significant impact on iodine transport in the RCS. Experimentally it has been shown that the formation of gaseous iodine is promoted in oxidising conditions, as caesium can be completely consumed to form caesium polymolybdates and is thus not available for reacting with gaseous iodine and leading to CsI aerosols. In reducing conditions, CsI remains the dominant form of iodine, as the amount of oxygen is not sufficient to allow formation of quantitative caesium polymolybdates. An I–Mo–Cs model has been developed and it reproduces well the experimental trends on iodine transport

Optimising Refined Bleached Deodorized Palm Stearin For Its Crude Stearic Acid Iodine Value To Provide The Stable Specification Of Blended Stearic Acid Distillate Iodine Value

OpenAIRE

Ritonga, Muhammad Yusuf

2015-01-01

On the commercial scale, the quality standard of Blended Stearic Acid Distilled (BSAD) couldn’t be achieved by normal distillation. BSAD iodine value is mostly higher than maximum quality standard (0.2 mg/100 g), with the same iodine value (0.80 g/100 g) of feed Hydrogenated Splitted RBDPS Fatty Acid or HSRBDPSFA, feed capacity 5.5 ton/hour with bottom flash distiller temperature reaching 213oC. The separation and reduction of chemical impurities (so sensitive to oxidation/temperature/heat ch...

Urinary Iodine Concentrations Indicate Iodine Deficiency in Pregnant Thai Women but Iodine Sufficiency in Their School-Aged Children

NARCIS (Netherlands)

Gowachirapant, S.; Winichagoon, P.; Wyss, L.; Tong, B.; Baumgartner, J.; Boonstra, A.; Zimmermann, M.B.

2009-01-01

The median urinary iodine concentration (UI) in school-aged children is recommended for assessment of iodine nutrition in populations. If the median UI is adequate in school-aged children, it is usually assumed iodine intakes are also adequate in the remaining population, including pregnant women.

Analysis of the kinetic behaviour of iodine and caesium isotopes in the primary circuit of LWR's during severe fuel damage accidents

International Nuclear Information System (INIS)

Alonso, A.; Fernandez, S.; Buron, J.M.; Lopez, J.V.

1991-01-01

This State of the Art report deals with the chemical behaviour of caesium and iodine in the primary system, focusing particularly on kinetic chemical aspects. In case of a postulated severe accident in a nuclear reactor, cesium and iodine fission products are among the major contributors to health harm because of their high volatility and radiotoxicity. The extent of the release of such fission products to the environment depends on the effectiveness of transport through different structures in the reactor coolant system and within the reactor building. The release from fuel has been briefly studied; only those aspects concerning to iodine and caesium chemical forms when released have been reviewed; nevertheless the emphasis has been put on the transport of such elements and their species through the primary system. Some thermochemical equilibrium studies, applied to primary circuit conditions in LWR's, have been analyzed. The revision of the few kinetic studies existing on this matter has shown that kinetic behaviour of iodine and caesium isotopes in the primary circuit is an aspect poorly studied, despite the fact that kinetic aspects could have great importance on the chemical species formed under certain conditions. Other phenomena affecting iodine and caesium transport, besides chemical reactions, such as interactions with surfaces, aerosols or other chemical species have also been examined from available information on diverse experiments

Thin-film chemical sensors based on electron tunneling

Science.gov (United States)

Khanna, S. K.; Lambe, J.; Leduc, H. G.; Thakoor, A. P.

1985-01-01

The physical mechanisms underlying a novel chemical sensor based on electron tunneling in metal-insulator-metal (MIM) tunnel junctions were studied. Chemical sensors based on electron tunneling were shown to be sensitive to a variety of substances that include iodine, mercury, bismuth, ethylenedibromide, and ethylenedichloride. A sensitivity of 13 parts per billion of iodine dissolved in hexane was demonstrated. The physical mechanisms involved in the chemical sensitivity of these devices were determined to be the chemical alteration of the surface electronic structure of the top metal electrode in the MIM structure. In addition, electroreflectance spectroscopy (ERS) was studied as a complementary surface-sensitive technique. ERS was shown to be sensitive to both iodine and mercury. Electrolyte electroreflectance and solid-state MIM electroreflectance revealed qualitatively the same chemical response. A modified thin-film structure was also studied in which a chemically active layer was introduced at the top Metal-Insulator interface of the MIM devices. Cobalt phthalocyanine was used for the chemically active layer in this study. Devices modified in this way were shown to be sensitive to iodine and nitrogen dioxide. The chemical sensitivity of the modified structure was due to conductance changes in the active layer.

Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process

Energy Technology Data Exchange (ETDEWEB)

Ellett, Anna Judith

2009-07-01

The reduction of CO{sub 2} emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO{sub 2} Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global carbon mitigation effort. The oxyfuel process, which consists in the burning of coal in an oxygen-rich atmosphere to produce a flue gas highly concentrated in CO{sub 2}, is a technology considered for zero CO{sub 2} emission coal-fired power plants. The production of this O{sub 2}-rich combustion gas from air can be carried out using high purity oxygen separation membranes. Some of the most promising materials for this application are mixed ionic-electronic conducting (MIEC) materials with perovskite and K{sub 2}NiF{sub 4} perovskite-related structures. The present work examines the selection of La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58), La{sub 2}NiO{sub 4+{delta}}, Pr{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (PSCF58) and Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF50) as membrane materials for the separation of O{sub 2} and N{sub 2} in the framework of the oxyfuel process with flue gas recycling. Annealing experiments were carried out on pellets exposed to CO{sub 2}, water vapour, O{sub 2} and Cr{sub 2}O{sub 3} in order to determine the thermo-chemical resistance to the atmospheres and the high temperature conditions present during membrane operation in a coal-fired power plant. The degradation of their microstructure was investigated using Scanning Electron Microscopy (SEM) in combination with electron dispersive spectroscopy (EDS) as well as X-Ray Diffraction (XRD). Also, the oxygen permeation fluxes of selected membranes were investigated as a function of temperature. The membrane materials selected were characterised using thermo-analytical techniques such as precision thermogravimetric

Iodine 131 and 133 as Fission Indicators

Energy Technology Data Exchange (ETDEWEB)

Broda, E.

1944-07-01

This report was written by E. Broda at the Cavendish Laboratory (Cambridge) in September 1944 and is about the possible use of Iodine 131 and 133 as fission indicators. Additionally, the description of the chemical procedure for I 131 and I 133 and the corresponding results can be found in this report. (nowak)

Protection of Wood from Microorganisms by Laccase-Catalyzed Iodination

Science.gov (United States)

Engel, J.; Thöny-Meyer, L.; Schwarze, F. W. M. R.; Ihssen, J.

2012-01-01

In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I−) to iodine (I2) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

A prototype of an electric-discharge gas flow oxygen−iodine laser: I. Modeling of the processes of singlet oxygen generation in a transverse cryogenic slab RF discharge

Energy Technology Data Exchange (ETDEWEB)

Vagin, N. P.; Ionin, A. A., E-mail: aion@sci.lebedev.ru; Kochetov, I. V.; Napartovich, A. P.; Sinitsyn, D. V., E-mail: dsinit@sci.lebedev.ru; Yuryshev, N. N. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2017-03-15

The existing kinetic model describing self-sustained and electroionization discharges in mixtures enriched with singlet oxygen has been modified to calculate the characteristics of a flow RF discharge in molecular oxygen and its mixtures with helium. The simulations were performed in the gas plug-flow approximation, i.e., the evolution of the plasma components during their motion along the channel was represented as their evolution in time. The calculations were carried out for the O{sub 2}: He = 1: 0, 1: 1, 1: 2, and 1: 3 mixtures at an oxygen partial pressure of 7.5 Torr. It is shown that, under these conditions, volumetric gas heating in a discharge in pure molecular oxygen prevails over gas cooling via heat conduction even at an electrode temperature as low as ~100 K. When molecular oxygen is diluted with helium, the behavior of the gas temperature changes substantially: heat removal begins to prevail over volumetric gas heating, and the gas temperature at the outlet of the discharge zone drops to ~220–230 K at room gas temperature at the inlet, which is very important in the context of achieving the generation threshold in an electric-discharge oxygen−iodine laser based on a slab cryogenic RF discharge.

A prototype of an electric-discharge gas flow oxygen−iodine laser: I. Modeling of the processes of singlet oxygen generation in a transverse cryogenic slab RF discharge

International Nuclear Information System (INIS)

Vagin, N. P.; Ionin, A. A.; Kochetov, I. V.; Napartovich, A. P.; Sinitsyn, D. V.; Yuryshev, N. N.

2017-01-01

The existing kinetic model describing self-sustained and electroionization discharges in mixtures enriched with singlet oxygen has been modified to calculate the characteristics of a flow RF discharge in molecular oxygen and its mixtures with helium. The simulations were performed in the gas plug-flow approximation, i.e., the evolution of the plasma components during their motion along the channel was represented as their evolution in time. The calculations were carried out for the O 2 : He = 1: 0, 1: 1, 1: 2, and 1: 3 mixtures at an oxygen partial pressure of 7.5 Torr. It is shown that, under these conditions, volumetric gas heating in a discharge in pure molecular oxygen prevails over gas cooling via heat conduction even at an electrode temperature as low as ~100 K. When molecular oxygen is diluted with helium, the behavior of the gas temperature changes substantially: heat removal begins to prevail over volumetric gas heating, and the gas temperature at the outlet of the discharge zone drops to ~220–230 K at room gas temperature at the inlet, which is very important in the context of achieving the generation threshold in an electric-discharge oxygen−iodine laser based on a slab cryogenic RF discharge.

Kinetic bottlenecks to chemical exchange rates for deep-sea animals - Part 1: Oxygen

Science.gov (United States)

Hofmann, A. F.; Peltzer, E. T.; Brewer, P. G.

2012-10-01

Ocean warming will reduce dissolved oxygen concentrations which can pose challenges to marine life. Oxygen limits are traditionally reported simply as a static concentration thresholds with no temperature, pressure or flow rate dependency. Here we treat the oceanic oxygen supply potential for heterotrophic consumption as a dynamic molecular exchange problem analogous to familiar gas exchange processes at the sea surface. A combination of the purely physico-chemical oceanic properties temperature, hydrostatic pressure, and oxygen concentration defines the ability of the ocean to supply oxygen to any given animal. This general oceanic oxygen supply potential is modulated by animal specific properties such as the diffusive boundary layer thickness to define and limit maximal oxygen supply rates. Here we combine all these properties into formal, mechanistic equations defining novel oceanic properties that subsume various relevant classical oceanographic parameters to better visualize, map, comprehend, and predict the impact of ocean deoxygenation on aerobic life. By explicitly including temperature and hydrostatic pressure into our quantities, various ocean regions ranging from the cold deep-sea to warm, coastal seas can be compared. We define purely physico-chemical quantities to describe the oceanic oxygen supply potential, but also quantities that contain organism-specific properties which in a most generalized way describe general concepts and dependencies. We apply these novel quantities to example oceanic profiles around the world and find that temperature and pressure dependencies of diffusion and partial pressure create zones of greatest physical constriction on oxygen supply typically at around 1000 m depth, which coincides with oxygen concentration minimum zones. In these zones, which comprise the bulk of the world ocean, ocean warming and deoxygenation have a clear negative effect for aerobic life. In some shallow and warm waters the enhanced diffusion and

Do Thyroxine and Thyroid-Stimulating Hormone Levels Reflect Urinary Iodine Concentrations?

Science.gov (United States)

Soldin, Offie P.; Tractenberg, Rochelle E.; Pezzullo, John C.

2013-01-01

The toxicity of environmental chemicals such as nitrates, thiocynates, and perchlorates, some therapeutics, and dietary goitrogens can lower thyroidal iodine uptake and result in hypothyroidism and goiter. Iodine sufficiency, essential for normal thyroid hormone synthesis, is critical during gestation to assure that sufficient thyroxine (T4) and iodine reach the developing fetus. Spot urinary iodide (UI) measurements are used globally to indicate and monitor iodine sufficiency of populations. In individuals, however, UI are not routinely measured; instead, normal serum thyroid-stimulating hormone (TSH) and T4 concentrations serve as surrogate indicators of iodine sufficiency as well as thyroidal health. Our objective was to examine the relationship between UI concentrations and serum T4 and TSH concentrations in individuals in an ‘‘iodine-sufficient population.’’ Using a cross-sectional sample of the US population (n = 7628) from the National Health and Nutrition Examination Survey (NHANES III; 1988–1994) database, we examined the relationship among UI, T4, and TSH in pregnant and nonpregnant women and in men (15–44 years). There was a lack of relationship between UI (or UI/Cr) concentrations and serum T4 or TSH concentrations. Therefore, TSH and T4 are not appropriate markers of UI concentrations in this population. Monitoring the status of iodine nutrition of individuals in the United States may be important because serum TSH and T4 concentrations do not indicate low iodine status. PMID:15795649

Iodination and stability of somatostatin analogues: comparison of iodination techniques. A practical overview.

Science.gov (United States)

de Blois, Erik; Chan, Ho Sze; Breeman, Wouter A P

2012-01-01

For iodination ((125/127)I) of tyrosine-containing peptides, chloramin-T, Pre-Coated Iodo-Gen(®) tubes and Iodo-Beads(®) (Pierce) are commonly used for in vitro radioligand investigations and there have been reliant vendors hereof for decades. However, commercial availability of these radio-iodinated peptides is decreasing. For continuation of our research in this field we investigated and optimized (radio-)iodination of somatostatin analogues. In literature, radioiodination using here described somatostatin analogues and iodination techniques are described separately. Here we present an overview, including High Performance Liquid Chromatography (HPLC) separation and characterisation by mass spectrometry, to obtain mono- and di-iodinated analogues. Reaction kinetics of (125/127)I iodinated somatostatin analogues were investigated as function of reaction time and concentration of reactants, including somatostatin analogues, iodine and oxidizing agent. To our knowledge, for the here described somatostatin analogues, no (127)I iodination and optimization are described. (Radio-)iodinated somatostatin analogues could be preserved with a >90% radiochemical purity for 1 month after reversed phase HPLC-purification.

Modeling an Iodine Hall Thruster Plume in the Iodine Satellite (ISAT)

Science.gov (United States)

Choi, Maria

2016-01-01

An iodine-operated 200-W Hall thruster plume has been simulated using a hybrid-PIC model to predict the spacecraft surface-plume interaction for spacecraft integration purposes. For validation of the model, the plasma potential, electron temperature, ion current flux, and ion number density of xenon propellant were compared with available measurement data at the nominal operating condition. To simulate iodine plasma, various collision cross sections were found and used in the model. While time-varying atomic iodine species (i.e., I, I+, I2+) information is provided by HPHall simulation at the discharge channel exit, the molecular iodine species (i.e., I2, I2+) are introduced as Maxwellian particles at the channel exit. Simulation results show that xenon and iodine plasma plumes appear to be very similar under the assumptions of the model. Assuming a sticking coefficient of unity, iodine deposition rate is estimated.

Chemical and radiological toxicity of iodine isotopes. Experimental study on the rat at the perinatal stage

International Nuclear Information System (INIS)

Bourahla, K.

2000-01-01

The recommended prophylactic measure in the case of an exposure to radio-iodine is an excess take of stable iodine. During the perinatal stage, the thyroid is radio-sensible but also fragile with respect to an excess of iodine. This work performed on the rat, treats of the potential thyroidal toxicity of the prophylaxy and analyzes the early radio-lesions induced by 131 I. On the basis of microscopic (optical, electronic, ionic) and dosimetric studies (TSH, T4), four aspects are considered: 1 - the perinatal morpho-functional evolution (F18, J1, J4, J10, J21, J35); 2 - the consequences of an iodine overburden at three moments of the thyroid maturation (F16, F20 and J4); 3 - the effects on the thyroid cells growth of different iodine overburdens (4 g, 20 g, 100 g); and 4 - the radio-toxic effects (after 48 h) of 131 I taken at J5 (30 Gy) and at J35 (900 Gy). This work evidences the following points: 1 - the perinatal evolution of the thyroid tissue of the rat shows ultra-structural and follicular modifications and physiological follicular destructions; 2 - the variability of the iodine overburden effects: hyperactivity for overburdens at F16, tissue destruction with compensated hypothyroidism for overburdens at J5, no recognized thyroidal anomaly for the overburden at J20; 3 - the iodated overburden inhibits the start-up of the S-phase of the cellular cycle at a lower level (1/20); 4 - the 131 I taken at J5 (30 Gy) induces a lysis of the nucleic acids content, while 131 I taken at J35 (900 Gy) induces an important inflammatory reaction and some apoptosis phenomena. In summary, the stable iodine prophylactic measure can have two conjugated effects on the rat: an interesting action of thyroid cells growth inhibition, and a toxic action leading to an hyperactivity or a follicular destruction without hypothyroidism, depending on the maturation stage. The early effects of 131 I seem to be linked with the age. (J.S.)

Separation of iodine-131 from water using isotopic exchange with iodine-starch compound

International Nuclear Information System (INIS)

Ignatov, V.P.; Kolomejtseva, I.V.

1990-01-01

Conditions of iodine isotopic exchange with iodine-starch compound (ISC) were studied with the aim of compound utilizatoin for radioactive iodine separation from solution. It is shown that in pH range from 2 to 7 the degree of iodine extraction and coefficient of its distribution practically do not depend on pH, at pH>7 ISC destruction (decolorizing) starts and iodine extraction decreases. Rapid method of iodine separation from solution is suggested. The method can be used in radiochemical techniques. The degree of extraction equals 80 %, a higher degree of extraction can not be achieved owing to ISC formation peculiarities

Iodine budget in surface waters from Atacama: Natural and anthropogenic iodine sources revealed by halogen geochemistry and iodine-129 isotopes

International Nuclear Information System (INIS)

Álvarez, Fernanda; Reich, Martin; Snyder, Glen; Pérez-Fodich, Alida; Muramatsu, Yasuyuki; Daniele, Linda; Fehn, Udo

2016-01-01

Iodine enrichment in the Atacama Desert of northern Chile is widespread and varies significantly between reservoirs, including nitrate-rich “caliche” soils, supergene Cu deposits and marine sedimentary rocks. Recent studies have suggested that groundwater has played a key role in the remobilization, transport and deposition of iodine in Atacama over scales of millions-of-years. However, and considering that natural waters are also anomalously enriched in iodine in the region, the relative source contributions of iodine in the waters and its extent of mixing remain unconstrained. In this study we provide new halogen data and isotopic ratios of iodine ("1"2"9I/I) in shallow seawater, rivers, salt lakes, cold and thermal spring water, rainwater and groundwater that help to constrain the relative influence of meteoric, marine and crustal sources in the Atacama waters. Iodine concentrations in surface and ground waters range between 0.35 μM and 26 μM in the Tarapacá region and between 0.25 μM and 48 μM in the Antofagasta region, and show strong enrichment when compared with seawater concentrations (I = ∼0.4 μM). In contrast, no bromine enrichment is detected (1.3–45.7 μM for Tarapacá and 1.7–87.4 μM for Antofagasta) relative to seawater (Br = ∼600 μM). These data, coupled to the high I/Cl and low Br/Cl ratios are indicative of an organic-rich sedimentary source (related with an “initial” fluid) that interacted with meteoric water to produce a mixed fluid, and preclude an exclusively seawater origin for iodine in Atacama natural waters. Iodine isotopic ratios ("1"2"9I/I) are consistent with halogen chemistry and confirm that most of the iodine present in natural waters derives from a deep initial fluid source (i.e., groundwater which has interacted with Jurassic marine basement), with variable influence of at least one atmospheric or meteoric source. Samples with the lowest isotopic ratios ("1"2"9I/I from ∼215 to ∼1000 × 10"�

Iodine mineral waters

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Iluta Alexandru

2011-11-01

Full Text Available Iodine mineral waters are found especially in sub-Carpathian region, also in regions with Salif deposits. Waters are currently used iodine in drinking cure for chaps and Basedow. Are also indicated in balneology. Iodine water containing at least 1 mg L, there is pure iodine is usually given the nature of other types of mineral waters further: sodium chlorinated water (Bazna (50-70 mg iodine / l, Baile Govora (50 - 70 mg / l, Bălţăteşti (4-5 mg / l, salted Monteoru (30 mg / l, mine water mixed alkaline chlorination, sulphate, which are indicated for crenoterapie (hypo or isotonic to the bathrooms Olăneşti or Călimăneşti-Căciulata.

Non-self-sustained electric discharge in oxygen gas mixtures: singlet delta oxygen production

CERN Document Server

Ionin, A A; Kotkov, A A; Kochetov, I V; Napartovich, A P; Seleznev, L V; Sinitsyn, D V; Hager, G D

2003-01-01

The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O sub 2 : Ar : CO (or H sub 2) at the total gas pressures of 10-100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded approx 6 kJ l sup - sup 1 atm sup - sup 1 (150 kJ mol sup - sup 1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen-iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H sub 2 or D sub 2. The efficiency of singlet delta oxygen production can be as high as 40%.

Iodine status in neonates in Denmark: regional variations and dependency on maternal iodine supplementation

DEFF Research Database (Denmark)

Nøhr, S B; Laurberg, P; Børlum, K G

1994-01-01

Iodine status of 147 neonates born in five different regions of Denmark was evaluated in relation to the iodine content of breast milk and iodine supplementation taken by the mother. Approximately two-thirds of the women had not received iodine supplementation. They had low iodine concentrations...... in breast milk and urinary iodine concentrations of the neonates at day 5 were low. The median values (milk/urine) were 33.6/31.7 micrograms/l (Randers 22/26, Ringkøbing 29/16, Aalborg 36/31. Arhus 54/41 and Copenhagen 55/59 micrograms/l). Higher values were found in the group where tablets containing...... iodine had been taken (milk/urine: 57.0/61.0 micrograms/l). In general, the values are low compared with internationally recommended levels. We suggest that mothers without autoimmune thyroid disease should receive iodine supplementation in the form of vitamin/mineral tablets containing iodine (150...

The effect of preliminary processing and different methods of cooking on the iodine content and selected antioxidative properties of carrot (Daucus carota L. biofortified with (potassium iodine

Directory of Open Access Journals (Sweden)

Kapusta-Duch Joanna

2017-06-01

Full Text Available Carrot is a vegetable that contains many nutrients and has strong antioxidant activity as well as pro-health potential. The level of bioactive compounds is strongly connected with the production chain. The thermal treatment of food products induces several biological, physical and chemical changes. In this study, changes in the levels of iodine, total carotenoids, total polyphenols as well as the antioxidant activity of unpeeled and peeled controls and carrots biofortified with (potassium iodine (KJ during cultivation due to the cooking and steaming process were investigated. The use of thermal processes resulted in a lower concentration of iodine in the roots of the control as well as in carrots biofortified with (potassium iodine. In addition, peeling carrots caused higher losses of this trace element in the control and the biofortified carrots cooked or steamed for various times. In this study, a significant growth of the total carotenoids in peeled carrots biofortified with (potassium iodine and of the total polyphenols in unpeeled carrots biofortified with (potassium iodine under the influence of the cooking and steaming processes was observed compared with raw peeled and unpeeled biofortified carrots, respectively. Antioxidant activity significantly increased in the unpeeled and peeled carrots biofortified with (potassium iodine under all thermal treatments in comparison with the raw unpeeled and peeled biofortified carrots.

Urinary Iodine Clearance following Iodinated Contrast Administration: A Comparison of Euthyroid and Postthyroidectomy Subjects

Directory of Open Access Journals (Sweden)

Janice D. Ho

2014-01-01

Full Text Available Purpose. To compare iodine clearance following iodinated contrast administration in thyroidectomised thyroid cancer patients and euthyroid individuals. Methods. A convenience population (6 thyroidectomised thyroid cancer patients and 7 euthyroid controls was drawn from patients referred for iodinated contrast-enhanced computed tomography (CT studies. Subjects had sequential urine samples collected up to 6 months (50 samples from the thyroidectomised and 63 samples from the euthyroid groups. t-tests and generalised estimating equations (GEE were used to test for group differences in urinary iodine creatinine ratios. Results. Groups had similar urinary iodine creatinine ratios at baseline, with a large increase 2 weeks following iodinated contrast (P=0.005. Both groups had a return of urinary iodine creatinine ratios to baseline by 4 weeks, with no significant group differences overall or at any time point. Conclusions. Thyroidectomised patients did not have a significantly different urinary iodine clearance than euthyroid individuals following administration of iodinated contrast. Both had a return of urinary iodine creatinine ratios to baseline within 4 weeks.

[Study on the iodine nutrition and iodine deficiency disorders status in pasturing areas of Tibet-a non-epidemic area of iodine deficiency disorders in serious iodine deficiency district].

Science.gov (United States)

DU, Dan; Li, Su-Mei; Li, Xiu-Wei; Wang, Hai-Yan; Li, Shu-Hua; Nima, Cangjue; Danzeng, Sangbu; Zhuang, Guang-Xiu

2010-08-01

To explore the status of iodine nutrition and iodine deficiency disorders in the pasturing areas and agricultural regions in Tibet. 30 families were selected respectively in pastoral Dangxiong county and agricultural Qushui county of Lasa. Drinking water and edible salt were collected for testing the iodine contents. In each type of the following populations including children aged 8 - 10, women of child-bearing age and male adults, 50 subjects were randomly sampled to examine their urinary iodine contents. Among them, 50 children and 50 women were randomly selected for goiter examination by palpation. Water iodine content was less than 2 µg/L, both in pasturing area and in agricultural areas. There was no iodized salt used in the families of pasturing areas, while 90% people consumed iodized salt in agricultural areas. The median of urinary iodine in pasturing area was 50.2 µg/L, significantly lower than that of agricultural area (193.2 µg/L). However, the goiter rate of children and women in pasturing area was significantly lower than that in agricultural area. Although iodine intake of populations in pasturing area of Tibet was severely deficient, there was no epidemic of Iodine Deficiency Disorders. This phenomenon noticed by the researchers deserved further investigation.

Iodine deficiency disorders

Energy Technology Data Exchange (ETDEWEB)

Ali, S M [Pakistan Council for Science and Technology, Islamabad (Pakistan)

1994-12-31

Iodine deficiency (IDD) is one of the common problem in the diet. Iodine deficiency as prevalence of goiter in population occurs in the mountainous areas. There is consensus that 800 million people are at risk of IDD from living in iodine deficient area and 190 million from goiter. Very high prevalence of IDD in different parts of the world are striking. It has generally observed that in iodine-deficient areas about 50% are affected with goiter, 1-5% from cretinsim and 20% from impaired mental and/or mortor function. (A.B.).

Fabrication and processing of next-generation oxygen carrier materials for chemical looping combustion

Energy Technology Data Exchange (ETDEWEB)

Nadarajah, Arunan [Univ. of Toledo, OH (United States)

2017-04-26

Among numerous methods of controlling the global warming effect, Chemical Looping Combustion is known to be the most viable option currently. A key factor to a successful chemical looping process is the presence of highly effective oxygen carriers that enable fuel combustion by going through oxidation and reduction in the presence of air and fuel respectively. In this study, CaMnO_3-δ was used as the base material and doped on the A-site (Sr or La) and B-site (Fe, Ti, Zn and Al) by 10 mol % of dopants. Solid state reaction followed by mechanical extrusion (optimized paste formula) was used as the preparation method A series of novel doped perovskite-type oxygen carrier particles (Ca_xLa (Or Sa)_1-x Mn_1-yByO_3-δ (B-site = Fe, Ti, Al, or Zr)) were synthesized by the proposed extrusion formula. The produced samples were characterized with XRD, SEM, BET and TGA techniques. According to the results obtained from TGA analysis, the oxygen capacity of the samples ranged between 1.2 for CLMZ and 1.75 for CSMF. Reactivity and oxygen uncoupling behaviors of the prepared samples were also evaluated using a fluidized bed chemical looping reactor using methane as the fuel at four different temperatures (800, 850, 900, 950 °C). All of the oxygen carriers showed oxygen uncoupling behavior and they were able to capture and release oxygen. Mass-based conversion of the perovskites was calculated and temperature increase proved to increase the mass-based conversion rate in all of the samples under study. Gas yield was calculated at 950 °C as well, and results showed that CLMZ, CM and CSMF showed 100% gas yields and CLMF and CSMZ showed approximately 85% yield in fluidized bed reactor, which is a high and acceptable quantity. Based on extended reactor tests the modified calcium manganese perovskite structures (CSMF) can be a good candidate for future pilot tests.

Iodine deficiency and thyroid disorders.

Science.gov (United States)

Zimmermann, Michael B; Boelaert, Kristien

2015-04-01

Iodine deficiency early in life impairs cognition and growth, but iodine status is also a key determinant of thyroid disorders in adults. Severe iodine deficiency causes goitre and hypothyroidism because, despite an increase in thyroid activity to maximise iodine uptake and recycling in this setting, iodine concentrations are still too low to enable production of thyroid hormone. In mild-to-moderate iodine deficiency, increased thyroid activity can compensate for low iodine intake and maintain euthyroidism in most individuals, but at a price: chronic thyroid stimulation results in an increase in the prevalence of toxic nodular goitre and hyperthyroidism in populations. This high prevalence of nodular autonomy usually results in a further increase in the prevalence of hyperthyroidism if iodine intake is subsequently increased by salt iodisation. However, this increase is transient because iodine sufficiency normalises thyroid activity which, in the long term, reduces nodular autonomy. Increased iodine intake in an iodine-deficient population is associated with a small increase in the prevalence of subclinical hypothyroidism and thyroid autoimmunity; whether these increases are also transient is unclear. Variations in population iodine intake do not affect risk for Graves' disease or thyroid cancer, but correction of iodine deficiency might shift thyroid cancer subtypes toward less malignant forms. Thus, optimisation of population iodine intake is an important component of preventive health care to reduce the prevalence of thyroid disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Iodine-129 and Iodine-127 speciation in groundwater at the Hanford Site, U.S.: iodate incorporation into calcite

International Nuclear Information System (INIS)

Zhang, Saijin; Yeager, Chris; Wellman, Dawn M.; Santschi, Peter H.

2013-01-01

The Hanford Site, the most contaminated nuclear site in the United States, has large radioactive waste plumes containing high 129I levels. The geochemical transport and fate of radioiodine depends largely on its chemical speciation that is greatly affected by environmental factors. This study reports, for the first time, the speciation of stable and radioactive iodine in the groundwater from the Hanford Site. Iodate was the dominant species and accounts for up to 84%, followed by organo-iodine and minimal levels of iodide. The relatively high pH and oxidizing environment may have prevented iodate reduction. Our results identified that calcite precipitation caused by degassing of CO2 during deep groundwater sampling incorporated between 7 to 40% of dissolved iodine (including 127I and 129I) that was originally in the groundwater, transforming dissolved to particulate iodate during sampling. In order to understand the mechanisms underlying iodine incorporation by calcite, laboratory experiments were carried out to replicate this iodine sequestering processes. Two methods were utilized in this study, 1) addition of sodium carbonate; 2) addition of calcium chloride followed by sodium carbonate where the pH was well controlled at ~8.2, which is close to the average pH of Hanford Site groundwater. It was demonstrated that iodate was the main species incorporated into calcite and this incorporation process could be impeded by elevated pH and decreasing ionic strength in groundwater. This study provides critical information for predicting the long-term fate and transport of 129I at the Hanford Site and reveals a potential means for improved remediation strategies of 129I

Iodine Status in Pregnant & Breastfeeding Women

DEFF Research Database (Denmark)

Andersen, Stine Linding

Iodine is required for the synthesis of thyroid hormones, which are crucial regulator of early brain development. The source of iodine in the fetus and the breastfed infant is maternal iodine, and adequate iodine intake in pregnant and breastfeeding is of major concern. Severe iodine deficiency can...... cause irreversible brain damage, whereas the consequences of mild to moderate iodine deficiency are less clear. Denmark was previously iodine deficient with regional differences (mild iodine deficiency in East Denmark and moderate iodine deficiency in West Denmark), and also pregnant and breastfeeding...... women suffered from iodine deficiency. A mandatory iodine fortification of household salt and salt used for commercial production of bread was introduced in Denmark in the year 2000. The PhD thesis investigates intake of iodine supplements and urinary iodine status in Danish pregnant and breastfeeding...

Radioactive iodine and environmental and sanitary effects - bibliographic study and quantification

International Nuclear Information System (INIS)

Guetat, Ph.; Armand, P.; Monfort, M.; Fritsch, P.; Flury Herard, A.; Menetrier, F.; Bion, L.; Schoech, C.; Masset, S.

2004-01-01

This document is intended to a large public. It reviews the different parameters needed to evaluate the potential act o radioactive releases from the emission to public. Its objectives are to evaluate the importance of different exposure pathways and to assess efficiency of the possible interventions for large public. The main conclusions are summarised hereafter: The radioactive decay chains have to be taken into account to evaluate the iodine source term in the nuclear plants in the case of fission accidents. The physico-chemical forms of iodine are important in order to determine the released activity and deposited activity on the soil. The isotopes to be taken into account are mainly iodine 131 for radiological assessments and also iodine 133 for the nuclear reactor accidents, and the chain Tellurium-Iodine 132 when no particulate filtration exists. Iodine 129 in French reprocessing plant cannot lead to significant accidents. The dominant exposure pathways are related to the consumption of contaminated food products (vegetable, milk) for the inorganic iodine. The iodine transfer to goat and sheep milk is greater than the one to cow milk. The meat production of herbivores at field is the most sensitive. The interest to remove rapidly herbivore from pasture appears relatively clearly. The banning of consumption of local contaminated food products (vegetables and meats) may reduce by about a factor of thirteen the impact due to iodine 131. The youngest the population is, the greatest are the thyroid radiosensitivity and variability within the population. Oral administration of stable iodine limits transfers to maternal milk and foetal thyroid. Ingestion of stable iodine is complementary to consumption banning of local contaminated food products. The earliest the ingestion is, the greatest is the efficiency. 0,1 TBq of 131 iodine released at a low height involves only limited and local actions whereas the release of 10 TBq involves direct and immediate protection

Regenerable mixed copper-iron-inert support oxygen carriers for solid fuel chemical looping combustion process

Energy Technology Data Exchange (ETDEWEB)

Siriwardane, Ranjani V.; Tian, Hanjing

2016-12-20

The disclosure provides an oxygen carrier for a chemical looping cycle, such as the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The oxygen carrier is comprised of at least 24 weight % (wt %) CuO, at least 10 wt % Fe2O3, and an inert support, and is typically a calcine. The oxygen carrier exhibits a CuO crystalline structure and an absence of iron oxide crystalline structures under XRD crystallography, and provides an improved and sustained combustion reactivity in the temperature range of 600.degree. C.-1000.degree. C. particularly for solid fuels such as carbon and coal.

Consuming iodine enriched eggs to solve the iodine deficiency endemic for remote areas in Thailand

Directory of Open Access Journals (Sweden)

Teeyapant Punthip

2010-12-01

Full Text Available Abstract Background Evidence showed that the occurrence of iodine deficiency endemic areas has been found in every provinces of Thailand. Thus, a new pilot programme for elimination of iodine deficiency endemic areas at the community level was designed in 2008 by integrating the concept of Sufficient Economic life style with the iodine biofortification of nutrients for community consumption. Methods A model of community hen egg farm was selected at an iodine deficiency endemic area in North Eastern part of Thailand. The process for the preparation of high content iodine enriched hen food was demonstrated to the farm owner with technical transfer in order to ensure the sustainability in the long term for the community. The iodine content of the produced iodine enriched hen eggs were determined and the iodine status of volunteers who consumed the iodine enriched hen eggs were monitored by using urine iodine excretion before and after the implement of iodine enrichment in the model farm. Results The content of iodine in eggs from the model farm were 93.57 μg per egg for the weight of 55 - 60 g egg and 97.76 μg for the weight of 60 - 65 g egg. The biological active iodo-organic compounds in eggs were tested by determination of the base-line urine iodine of the volunteer villagers before and after consuming a hard boiled iodine enriched egg per volunteer at breakfast for five days continuous period in 59 volunteers of Ban Kew village, and 65 volunteers of Ban Nong Nok Kean village. The median base-line urine iodine level of the volunteers in these two villages before consuming eggs were 7.00 and 7.04 μg/dL respectively. After consuming iodine enriched eggs, the median urine iodine were raised to the optimal level at 20.76 μg/dL for Ban Kew and 13.95 μg/dL for Ban Nong Nok Kean. Conclusions The strategic programme for iodine enrichment in the food chain with biological iodo-organic compound from animal origins can be an alternative method to

Iodine in meat in Macedonia

International Nuclear Information System (INIS)

Bogdanov, Bogdan; Gonev, Mihajlo; Tadzher, Isak

2000-01-01

Iodine deficiency in Macedonia still persists in a mild form. In 1999 the iodination of salt rose to 20 m gr iodine in Kg salt. The consumption of salt diminished after the last war from 20-30 gr salt per day to 10-20 gr salt daily. This shows that the problem of the elimination of iodine deficiency is being vigorously tackled. Since 1956 the iodine in salt in Macedonia rose to 10 m gr KI/Kg salt. The content of iodine in the Macedonian diet seems to be important. The amount of iodine in milk, eggs and bread is low as found by the investigation of MANU. The content of iodine in meat is low, compared to British meat is 10 times lower. The average iodine content in Macedonian meat is 95.15 micro gr per Kg, whereas in British meat it is 850-1510 micro gr iodine per k gr meat. (Original)

Spectroscopic characterisation of iodine deposits on 18%Cr/8%Ni and mild steel surfaces oxidised in CO2/CH3I gas mixtures

International Nuclear Information System (INIS)

Tyler, J.W.

1987-08-01

An understanding and quantification of iodine-131 attenuation within the gas circuit of a Commercial Advanced Gas-cooled Reactor is required for reactor safety assessments. To this end it is desirable to identify the chemical state of iodine in the gas phase or when deposited on reactor surfaces. Samples of 18%Cr/8%Ni and mild steel pipe, with iodine deposited on their surfaces following oxidation in CO 2 /CH 3 I gas mixtures, have been characterised in the present work using a variety of different spectroscopic techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, scanning Auger microscopy and X-ray diffraction. The chemical nature of the deposited iodine has been determined by X-ray photoelectron spectroscopy to be a metal iodide by correlating I 3d binding energies with those obtained from well characterised standards; the binding energies of the ejected I 3d photoelectrons being sensitive to the chemical environment experienced by the iodine atoms. The distribution of iodine throughout the oxide layers formed on these steels was determined by repeated cycles of argon-ion bombardment and analysis to build up an elemental depth profile whilst at the same time determining the chemical state of the elements present. Differences in oxide composition and morphology are discussed in relation to the deposition behaviour observed on 18%Cr/8%Ni and mild steel and it is suggested that gradual incorporation of the iodine occurs throughout the oxidation/deposition period. (U.K.)

Iodine Hall Thruster

Science.gov (United States)

Szabo, James

2015-01-01

Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars. In the Phase I project, Busek Company, Inc., tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high-flow iodine feed system and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200 to 600 V was demonstrated. Testing showed that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering a slightly higher thrust-to-power (T/P) ratio. In Phase II, a complete iodine-fueled system was developed, including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW; however, it can be deeply throttled as well as clustered to much higher power levels. The technology also can be scaled to greater than 100 kW per thruster to support megawatt-class missions. The target thruster efficiency for the full-scale system is 65 percent at high specific impulse (Isp) (approximately 3,000 s) and 60 percent at high thrust (Isp approximately 2,000 s).

Spectroscopic analysis of the powdery complex chitosan-iodine

Science.gov (United States)

Gegel, Natalia O.; Babicheva, Tatyana S.; Belyakova, Olga A.; Lugovitskaya, Tatyana N.; Shipovskaya, Anna B.

2018-04-01

A chitosan-iodine complex was obtained by modification of polymer powder in the vapor of an iodine-containing sorbate and studied by electron and IR spectroscopy, optical rotation dispersion. It was found that the electronic spectra of an aqueous solution of the modified chitosan (the source one and that stored for a year) showed intense absorption bands of triiodide and iodate ions, and also polyiodide ions, bound to the macromolecule by exciton bonding with charge transfer. Analysis of the IR spectra shows destruction of the network of intramolecular and intermolecular hydrogen bonds in the iodinated chitosan powder in comparison with the source polymer and the formation of a new chemical substance. E.g., the absorption band of deformation vibrations of the hydroxyl group disappears in the modified sample, and that of the protonated amino group shifts toward shorter wavelengths. The intensity of the stretching vibration band of the glucopyranose ring atoms significantly reduces. Heating of the modified sample at a temperature below the thermal degradation point of the polymer leads to stabilization of the chitosan-iodine complex. Based on our studies, the hydroxyl and amino groups of the aminopolysaccharide have been recognized as the centers of retention of polyiodide chains in the chitosan matrix.

Deposition of particles and iodine to outdoor surfaces and in the respiratory tract

International Nuclear Information System (INIS)

Garland, J.A.

1988-01-01

Dry deposition of particles depends strongly on particle size, and is also influenced by the geometry of the surface and weather parameters. Precipitation scavenging is also influenced to some degree by particle size, but hygroscopic properties of soluble particles are also likely to enhance deposition in precipitation. Similar comments apply in the respiratory tract, where particle size and solubility may influence the extent and site of deposition: the site is important for insoluble particles at least since it determines retention time in the body. Thus measurement of particle size and investigation of solubility would be valuable in interpreting deposition inhalation and air concentration observations. Iodine has several chemical forms in the air. It is valuable to sample in such a way that different forms are partitioned, although there is some uncertainty in their identification. The rate of deposition to vegetation depends strongly on the chemical form of the iodine, but the vapour forms of iodine that occur in the atmosphere may all be retained efficiently on inhalation

Chemical and physical factors which control the substitution reactions of direct fission-produced iodine with gaseous methane and the methyl halides

International Nuclear Information System (INIS)

Kikuchi, M.; Church, L.B.

1976-01-01

The factors controlling the hydrogen and halogen substitution reactions resulting from direct fission-produced iodine isotopes (*I) with gaseous methane and methyl halides were investigated. The chemical reaction probabilities, corrected for any secondary decomposition, were compared as a function of various chemical and physical parameters. These include carbon-halogen bond strength, halogen electronegativity, volume and cross sectional area of the substituted and neighboring atoms. On the basis of this analysis, it is concluded that *I-for-X (where X = H, F, Cl, Br and I) substitution reactions are controlled by the cross sectional area of the X atom. The *I-for-H substitution probability is reduced in proportion to the volume of X, suggesting that steric interference is the dominant factor influencing the reaction probability. (orig.) [de

Chemical homogeneity in the Orion Association: Oxygen abundances of B stars

Directory of Open Access Journals (Sweden)

Lanz T.

2012-02-01

Full Text Available We present non-LTE oxygen abundances for a sample of B stars in the Orion association. The abundance calculations included non-LTE line formation and used fully blanketed non-LTE model atmospheres. The stellar parameters were the same as adopted in the previous study by Cunha & Lambert (1994. We find that the young Orion stars in this sample of 10 stars are described by a single oxygen abundance with an average value of A(O = 8.78 and a small dispersion of ±0.05, dex which is of the order of the uncertainties in the analysis. This average oxygen abundance compares well with the average oxygen abundance obtained previously in Cunha & Lambert (1994: A(O = 8.72 ± 0.13 although this earlier study, based upon non-blanketed model atmospheres in LTE, displayed larger scatter. Small scatter of chemical abundances in Orion B stars had also been found in our previous studies for neon and argon; all based on the same effective temperature scale. The derived oxygen abundance distribution for the Orion association compares well with other results for the oxygen abundance in the solar neighborhood.

Dissolution off-gases at the marcoule pilot facility: Iodine trapping and off-gas characterization unit

International Nuclear Information System (INIS)

Pouyat, D.; Vignau, B.; Roux, J.P.

1993-01-01

The Marcoule Pilot Reprocessing Facility (APM) reprocesses spent fuel from light water reactors and fast breeder reactors. A batch dissolution process is used with an annual throughput capacity of 5 metric tons. The off-gas treatment unit is described together with its characterization laboratory in order to highlight the functions and potential of the facilities. The objectives are consistent with the Marcoule site policy regarding diminished iodine release and investigation of the off-gas treatment process. The equipment used to meet these objectives is described from a functional standpoint. The facility implements measurement techniques to allow continuous quantitative measurements of nitrogen oxides, oxygen, iodine and krypton, as well as continuous monitoring of the demister inlet flow by γ spectrometry. Sorbents used for iodine trapping may be tested over a wide range of operating conditions (temperature, flow rate, iodine concentration) with representative dissolution off-gases. An X-ray and γ counting system is used to assess the activity of the adsorbed radionuclides, notably 129 I

Marine geochemistry of iodine

International Nuclear Information System (INIS)

Kennedy, H.; Elderfield, H.

1985-01-01

Iodine has long been classified as a biophilic element with analyses showing that iodine is strongly enriched, relative to seawater concentrations in both plankton and particulate matter and that the concentration of iodine found in surface sediments is still further enriched relative to that found in the sedimenting particulate matter. The extent of enrichment of iodine relative to carbon in deep sea surface sediments has been shown to depend on the carbon accumulation rate. Iodine decomposition rates have been calculated and are shown to vary with the sedimentation rate in the same manner as has been shown for organic carbon. Vertical profiles of total dissolved iodine, iodate and iodide in interstitial waters of sediments from the north east Atlantic are characterised by three zones of reaction as identified by changes in the concentration of iodate and iodide. These reaction zones represent (i) iodide production (ii) iodide oxidation and (iii) iodate reduction. Pore water and solid phase iodine profiles from cores containing turbidite units have shown that iodine, released to pore waters as iodide during the oxidation of the organic matter, has been scavenged after diffusing upwards into a less reducing region of the sediment. (author)

Environmental sciences: general. 1. Evaluation of Iodine Reactions with Nuclear Aerosols by DRIFT

International Nuclear Information System (INIS)

Riggs, C.A.; Tompson, R.V.; Ghosh, T.K.; Loyalka, S.K.

2001-01-01

Nuclear source term computations require databases for iodine vapor reactions with cesium compounds. We have explored measurements of iodine vapor [I 2(g) ] reactions with cesium carbonate particles [CsCO 3(s) ] using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy in the far infrared region for iodine vapor concentrations typical of post-transient conditions in a pressurized water reactor containment. Cesium hydroxide (CsOH) in aerosol form is likely a significant source of radio-cesium released during a reactor transient. As shown in Eq. (1), CsOH (s) particles can combine with iodine gas to form cesium iodide [CsI (s) ] particles. Equations (2) and (3) present a two-step method where the CsOH (s) particles combine with carbon dioxide [CO 2(g) ] found in air to form Cs 2 CO 3(s) particles, which then react with iodine gas to form CsI (s) particles: I 2(g) + 4CsOH (s) ↔ 2CsI (s) 12CsO (s) 12H 2 O (l) , (1) CO 2(g) 12CsOH (s) ↔ Cs 2 CO 3(s) + H 2 O, (2) and Cs 2 CO 3(s) 13I 2(g) ↔ 5CsI (s) + CsIO 3(s) + 3CO 2(g) . (3) We elected to study reactions with Cs 2 CO 3(s) rather than CsOH (s) particles because of significant analytical and handling challenges with the DRIFT attachment presented by the corrosive characteristics of CsOH (s) particles. Physical modifications to the DRIFT attachment, in addition to improved handling practices, need to be evaluated prior to proceeding with the study of CsOH (s) by this method. The reaction of cesium carbonate agglomerates with iodine could occur by surface adsorption and/or absorption. Physical adsorption depends on the surface area and porosity of the solid material. Chemical adsorption depends on the chemical properties of both the gas and the solid material. Beahm et al. previously used classical wet chemical methods to monitor the reaction products after the reaction occurred. The use of DRIFT allows the study of the predicted physical and chemical adsorption occurring on the Cs 2 CO 3(s) surface

Analysis of iodine content in seaweed by GC-ECD and estimation of iodine intake

Directory of Open Access Journals (Sweden)

Tai Sheng Yeh

2014-06-01

Full Text Available Edible seaweed products have been consumed in many Asian countries. Edible seaweeds accumulate iodine from seawater, and are therefore a good dietary source of iodine. An adequate consumption of seaweed can eliminate iodine deficiency disorders, but excessive iodine intake is not good for health. The recommended dietary reference intake of 0.15 mg/d and 0.14 mg/d for iodine has been established in the United States and Taiwan, respectively. In this study, 30 samples of seaweed were surveyed for iodine content. The samples included 10 nori (Porphyra, 10 wakame (Undaria, and 10 kombu (Laminaria products. The iodine in seaweed was derivatized with 3-pentanone and detected by gas chromatography-electron capture detector (GC-ECD. The method detection limit was 0.5 mg/kg. The iodine content surveyed for nori was 29.3–45.8 mg/kg, for wakame 93.9–185.1 mg/kg, and for kombu 241–4921 mg/kg. Kombu has the highest average iodine content 2523.5 mg/kg, followed by wakame (139.7 mg/kg and nori (36.9 mg/kg. The GC-ECD method developed in this study is a low-cost alternative to inductively coupled plasma-optical emission spectroscopy for iodine detection in seaweeds. The iodine intake from seaweed in the current survey was calculated and compared with the iodine dietary reference intake of Taiwan. The risk and benefit of seaweed consumption is also discussed.

Breast-Milk Iodine Concentrations and Iodine Levels of Infants According to the Iodine Status of the Country of Residence: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Nazeri, Pantea; Kabir, Ali; Dalili, Hosein; Mirmiran, Parvin; Azizi, Fereidoun

2018-01-01

Iodine, an essential micronutrient, plays a critical role in normal growth and development, especially during the first two years of life. This systematic review and meta-analysis is among the first to evaluate breast-milk iodine concentrations and infant iodine status in countries characterized by iodine sufficiency or deficiency. PubMed, Web of Science, Cochrane Library, Google Scholar, and other relevant databases, as well as reference lists of previous reviews, were searched for relevant studies published between 1986 and 2016. Mean or median breast-milk and infant urinary iodine concentrations, along with other relevant data, were extracted from eligible studies. Each study was assessed for quality and risk of bias. Of the 496 identified studies, 57 met the criteria for inclusion in the meta-analysis. The mean (confidence interval [CI]) iodine concentrations in maternal colostrum were 152.0 μg/L [CI 106.2-198.7 μg/L] and 57.8 μg/L [CI 41.4-74.1 μg/L] in iodine-sufficient and -deficient countries, respectively, indicating a significant difference between the two iodine statuses. By contrast, the corresponding values in mature milk did not differ significantly between mothers in iodine-sufficient and -deficient countries (71.5 μg/L [CI 51.0-92.0 μg/L] and 28.0 μg/L [CI -13.8 to 69.9 μg/L], respectively]. The weighted urinary iodine levels [CIs] of breast-fed infants in iodine-sufficient countries were significantly higher than those in iodine-deficient countries (164.5 μg/L [CI 116.4-212.7 μg/L] vs. 70.4 μg/L [CI 46.2-94.6 μg/L]). Similarly, a significant difference was observed in the pooled estimates of urinary iodine levels [CIs] among formula-fed infants in iodine-sufficient versus iodine-deficient countries (310.3 μg/L [CI 287.4-342.1 μg/L] vs. 38.3 μg/L [CI 23.4-53.2 μg/L]). The meta-analysis reveals that in iodine-sufficient countries, the mean iodine concentrations in colostrum and mature breast milk

Iodine volatilization from irradiated CsI solutions

Energy Technology Data Exchange (ETDEWEB)

Evans, G J; Panyan, E J [Toronto Univ., ON (Canada). Dept. of Chemical Engineering and Applied Chemistry

1996-12-01

A bench-scale, separate-effect, flow apparatus has been constructed to examine volatile iodine production rates in relation to a selection of the possible variables and conditions found in a containment structure with a breached reactor core. The constructed apparatus is designed to provide the widest possible range of data including gas and aqueous phase speciation for an established set of interfacial mass transfer parameters with known pH and dissolved oxygen levels. As the interfacial transfer of iodine is an important component in the understanding of iodine chemistry, commissioning of the constructed apparatus focused on establishing a well characterized set of mass transfer parameters for a variety of mixing conditions and solution volumes. Aqueous phase parameters, obtained using a method involving the sparging of the dissolved oxygen in the aqueous phase, were found to vary by one order of magnitude, from 1x10{sup -2} to 1x10{sup -3} dm/sec. Gas phase parameters also changeable by one order of magnitude, from 1x10{sup -1} to 1x10{sup -2} dm/sec, were studied more thoroughly as they were found to have a greater impact in the system. Two independent methods of analysis were used, one involving tri-iodide solutions, the other using relative humidity values. A selection of the acquired volatility rates in relation to the effect of pH are presented. The apparatus has been found to consistently provide rates up to one order of magnitude lower than modelled predictions. Specifically, for buffered solutions, rates of 2x10{sup -12} mol/min and 1x10{sup -10} mol/min for pH 9 and 5 respectively, have been found. Rates of 1x10{sup -11} mol/min and 6x10{sup -10} mol/min are predicted. Current efforts have addressed potential reasons for this apparent discrepancy, the major factor being the possible release of components from the stainless steel during irradiation. Efforts undertaken to ensure the validity of the results are emphasized. (Abstract Truncated)

Natural Ores as Oxygen Carriers in Chemical Looping Combustion

Energy Technology Data Exchange (ETDEWEB)

Tian, Hanjing; Siriwardane, Ranjani; Simonyi, Thomas; Poston, James

2013-08-01

Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. The use of natural minerals as oxygen carriers has advantages, such as lower cost and availability. Eight materials, based on copper or iron oxides, were selected for screening tests of CLC processes using coal and methane as fuels. Thermogravimetric experiments and bench-scale fixed-bed reactor tests were conducted to investigate the oxygen transfer capacity, reaction kinetics, and stability during cyclic reduction/oxidation reaction. Most natural minerals showed lower combustion capacity than pure CuO/Fe{sub 2}O{sub 3} due to low-concentrations of active oxide species in minerals. In coal CLC, chryscolla (Cu-based), magnetite, and limonite (Fe-based) demonstrated better reaction performances than other materials. The addition of steam improved the coal CLC performance when using natural ores because of the steam gasification of coal and the subsequent reaction of gaseous fuels with active oxide species in the natural ores. In methane CLC, chryscolla, hematite, and limonite demonstrated excellent reactivity and stability in 50-cycle thermogravimetric analysis tests. Fe{sub 2}O{sub 3}-based ores possess greater oxygen utilization but require an activation period before achieving full performance in methane CLC. Particle agglomeration issues associated with the application of natural ores in CLC processes were also studied by scanning electron microscopy (SEM).

Radioactive iodine intake through foodstuff

International Nuclear Information System (INIS)

Omomo, Yoichiro

1974-01-01

The transition of radioactive iodine to human bodies is affected by the amount of coexisting stable iodine. The intake of stable iodine through foodstuffs was studied from the stand point of I) discussion of the literature which states the approximate amounts of stable iodine contained in environmental materials, and II) the authors' research on the consumption of foodstuffs. For example, the amounts of iodine intake of fishermen living in Kuji-cho (Ibaragi Prefecture) was estimated from I and II, and was revealed as 2704p. The national average iodine intake was about 800p indicating that the former estimated value was remarkably high. Eighty Four per cent of the 2.7 mg iodine intake was taken from marine products, indicating that marine products are important sources of iodine supply. (Tsukamoto, Y.)

Ab initio atomic simulation of hydrogen and iodine effects in zirconium

International Nuclear Information System (INIS)

Domain, Ch.

2002-03-01

In this work we present ab initio atomic simulations concerning the effects of hydrogen and iodine in hexagonal zirconium. We first studied the point defects in the dilute Zr-H (and to a less extend Zr-H-O) systems and concluded that it is better described within the generalised gradient approximation for the exchange and correlation functional. We calculated the hydrogen thermal diffusion coefficient in solid solution that agree very well with the experimental values. The calculated formation energy of different self-interstitial configuration are rather small (around 3 eV) and close to each other indicating the high complexity of these defects. We studied the core structure of the screw dislocation that has a preferential prismatic spreading. We also calculated the gamma surface for different gliding planes. The influence of hydrogen, that induces a significant reduction of the gamma surfaces excess energies, allows to qualitatively explain experimental results regarding some hydrogen effects on hexagonal zirconium plastic deformation. We also discussed the effect of zirconium hydride stoichiometry on gamma surfaces. The results concerning the iodine and oxygen adsorption on zirconium surfaces, inducing the evaluation of the effective surface energy reduction as a function of the iodine partial pressure allow for a better description of iodine induced stress corrosion cracking of zirconium. (author)

FDA regulations regarding iodine addition to foods and labeling of foods containing added iodine12

Science.gov (United States)

Trumbo, Paula R

2016-01-01

The US Food and Drug Administration (FDA) regulates the addition of iodine to infant formulas, the iodization of salt, and the addition of salt and iodine to foods. The required amount of iodine in infant formulas is based on caloric content, and the label must provide the iodine content per 100 kcal. Cuprous iodide and potassium iodide may be added to table salt as a source of dietary iodine at a maximum amount of 0.01%; if added, the label must indicate that the salt is iodized. Table salt to which iodine has not been added must bear the statement, “This salt does not supply iodide, a necessary nutrient.” If a nutrient is to be appropriately added to a food for the purpose of correcting a dietary insufficiency, there should be sufficient scientific information available to demonstrate a nutritional deficiency and/or identify a public health problem. Furthermore, the population groups that would benefit from the proposed fortification should be identified. If iodine is added to a food, the percent Daily Value of iodine must be listed. There are no FDA regulations governing ingredient standards for dietary supplements. As a result, some dietary supplements include iodine and others do not. If a supplement contains iodine, the Supplement Facts label must list iodine as a nutrient ingredient. If iodine is not listed on the Supplement Facts label, then it has not been added. There are similarities between the FDA, which establishes US food regulations and policies, and the Codex Alimentarius (Codex), which develops international food standards and guidelines under the aegis of the FAO and the WHO. Both the FDA and Codex call for the labeling of table salt to indicate fortification with iodine, voluntary labeling of iodine on foods, and a Daily Value (called a Nutrient Reference Value by Codex) of 150 μg for iodine. PMID:27534626

LWR severe accident simulation: Iodine behaviour in FPT2 experiment and advances on containment iodine chemistry

Energy Technology Data Exchange (ETDEWEB)

Girault, N., E-mail: nathalie.girault@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3 - 13115 St.-Paul-lez-Durance (France); Bosland, L. [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3 - 13115 St.-Paul-lez-Durance (France); Dickinson, S. [National Nuclear Laboratory, Harwell, Oxon OX11 0QT (United Kingdom); Funke, F. [AREVA NP Gmbh, PO Box 1109, 91001 Erlangen (Germany); Guentay, S. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Herranz, L.E. [Centro des Investigaciones Energeticas, MedioAmbiantales y Tecnologicas, av. Complutense 2, 28040 Madrid (Spain); Powers, D. [Sandia National Laboratories, New Mexico, PO Box 5800, Albuquerque, NM 87185 (United States)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Short term gaseous iodine fraction can be produced either in primary circuit or on containment condensing surfaces. Black-Right-Pointing-Pointer Gaseous radiolytic reactions convert volatile iodine into non-volatile iodine oxide particulates. Black-Right-Pointing-Pointer Alkaline and evaporating sump decrease the iodine volatility in containment. Black-Right-Pointing-Pointer Release of volatile iodine from containment surfaces explained the long term stationary residual gaseous iodine concentration. - Abstract: The Phebus Fission Product (FP) Program studies key phenomena of severe accidents in water-cooled nuclear reactors. In the framework of the Phebus program, five in-pile experiments have been performed that cover fuel rod degradation and behaviour of fission products released via the coolant circuit into the containment vessel. The focus of this paper is on iodine behaviour during the Phebus FPT2 test. FPT2 used a 33 GWd/t uranium dioxide fuel enriched to 4.5%, re-irradiated in situ for 7 days to a burn-up of 130 MWd/t. This test was performed to study the impact of steam-poor conditions and boric acid on the fission product chemistry. For the containment vessel, more specifically, the objective was to study iodine chemistry in an alkaline sump under evaporating conditions. The iodine results of the Phebus FPT2 test confirmed many of the essential features of iodine behaviour in the containment vessel provided by the first two Phebus tests, FPT0 and FPT1. These are the existence of an early gaseous iodine fraction, the persistence of low gaseous iodine concentrations and the importance of the sump in suppressing the iodine partitioning from sump to atmosphere. The main new insights provided by the Phebus FPT2 test were the iodine desorption from stainless steel walls deposits and the role of the evaporating sump in further iodine depletion in the containment atmosphere. The current paper presents an interpretation of

The iodine species and their behavior in the dissolution of spent-fuel specimens

International Nuclear Information System (INIS)

Sakurai, T.; Takahashi, A.; Ishikawa, N. Adachi, T.; Komaki, Y.; Ohnuki, M.

1992-01-01

In this paper, spent-fuel specimens (∼3 g each) with a burnup of 21 to 39 GWd/t were dissolved in 30 ml of 4 M HNO 3 at 100 degrees C, and the distribution of iodine and its chemical forms in the solution were studied. A small quantity of the iodine was conveyed to the insoluble residue (up to 2.3%), some remained in the fuel solution (up to 9.7%), and the balance was in the off-gas. Iodine was not deposited on the fuel cladding. Organic iodides were only ∼6.5% or less of the total amount of iodine in the off-gas. The fuel solution included iodine species that were difficult to expel by NO 2 sparging alone (27 to 46% of the iodine in the solution). These species were ascribed to be the colloids of AgI and PdI 2 . Iodate (IO - 3 ) was a rather minor iodine species in dissolution in ∼4 M HNO 3 . A thermochemical calculation also supports these results, indicating that the quantity of IO - 3 is ≤1.7 x 10 -4 % of the iodine fed to 4 M HNO 3 and that the colloid of AgI can be formed when the concentration of I - is ≥5.3 x 10 -10 M

Radioactive Iodine Treatment for Hyperthyroidism

Science.gov (United States)

... Balance › Radioactive Iodine for Hyperthyroidism Fact Sheet Radioactive Iodine for Hyperthyroidism April, 2012 Download PDFs English Zulu ... prepare for RAI or surgery. How does radioactive iodine treatment work? Iodine is important for making thyroid ...

Roles of microbial activities on the distribution and speciation of iodine in the soil environment

International Nuclear Information System (INIS)

Muramatsu, Yasuyuki; Yoshida, Satoshi; Amachi, Seigo

2000-01-01

The chemical species of iodine in the environment are expected to be influenced by the activities of microorganisms. In this paper, the roles of microbial activities in the accumulation and loss of iodine in soils were studied. Concentrations of stable iodine in several types of soils were determined by ICP-MS (Inductively Coupled Plasma Mass Spectroscopy). High iodine concentrations were found in upland soils, particularly in Andosol, while the concentrations in lowland soils were considerably lower. Accumulation of iodine in soils was explained by the effects of microorganisms and/or their products (e.g. enzymes). Iodine was observed to be desorbed from the flooded soils due to the reducing conditions (low Eh) created by the microbial activities. From the soil-rice plant system biogenesis methyliodide was found to be evaporated into the atmosphere. In order to study the mechanisms of volatile iodine production from the soil environment, a reliable method using 125 I tracer was established. Soil solution and bacterial cell suspension were incubated using this method, and it was found that volatile organic iodine was produced due to microbial activities (including bacterial activities). (author)

Effect of service aging on iodine retention of activated charcoals

International Nuclear Information System (INIS)

Evans, A.G.

1976-01-01

The Savannah River reactor confinement systems are continuously operated offgas cleanup systems whose components include moisture separators, HEPA filters, and halogen adsorber beds of activated charcoal. Charcoal is removed from the system periodically and subjected to a variety of physical, chemical, and iodine penetration tests to ensure that the system will perform within specification in the event of an accidental release of activity from the reactor. Tests performed on the charcoals include pH measurement of water extracts, particle size distribution, ignition temperature, high-temperature (180 0 C) iodine penetration, and iodine penetration in an intense radiation field at high humidity. Charcoals used in the systems include carbon Types 416 (unimpregnated), G-615 (impregnated with 2 percent TEDA and 2 percent KI), and GX-176 (impregnated with 1 percent TEDA and 2 percent KI). Performance data are presented and compared

Recent developments in iodine chemistry in Canada. Present and future applications to reactor safety

International Nuclear Information System (INIS)

Fluke, R.J.; Weaver, K.R.; Kupferschmidt, W.C.H.; Wren, J.C.; Ball, J.M.; Evans, G.J.

1997-01-01

In Canada, there exists a mature research programme directed towards resolving the nuclear safety and licensing questions surrounding fission product iodine. This integrated programme has had the long term objectives of developing a mechanistic understanding of the important aspects of iodine behaviour in containment, and of producing a mechanistic computer code to predict iodine behaviour under conditions of interest. The research is funded by Canadian Utilities and AECL through the CANDU Owners Group. In parallel with the research, an applications effort is underway to put existing research results into service for the resolution of reactor safety and licensing issues, as well as to identify and develop solutions for more comprehensive problems, such as chemical mitigation strategies to control post-accident iodine release. The present paper describes (a) the present status and objectives of R and D on iodine, its recent evolution and its significant achievements, (b) the analytical tools that are emerging from this programme and (c) existing and planned future applications of the results of the iodine R and D programme. The author concludes with an assessment of the impact that the iodine programme has had on reactor safety and licensing questions in Canada

Estimation of iodine intake from various urinary iodine measurements in population studies

DEFF Research Database (Denmark)

Vejbjerg, P.; Knudsen, N.; Perrild, H.

2009-01-01

Background: Iodine intake is often measured by a surrogate measure, namely urine iodine excretion as almost all ingested iodine is excreted in the urine. However, the methods for urine collection and the reporting of the results vary. These methods, and their advantages and disadvantages, are con...

Suboptimal Iodine Concentration in Breastmilk and Inadequate Iodine Intake among Lactating Women in Norway.

Science.gov (United States)

Henjum, Sigrun; Lilleengen, Anne Marie; Aakre, Inger; Dudareva, Anna; Gjengedal, Elin Lovise Folven; Meltzer, Helle Margrete; Brantsæter, Anne Lise

2017-06-22

Breastfed infants depend on sufficient maternal iodine intake for optimal growth and neurological development. Despite this, few studies have assessed iodine concentrations in human milk and there is currently no published data on iodine status among lactating women in Norway. The aim of this study was to assess iodine concentrations in breast milk (BMIC) in lactating women and estimate iodine intake. Five Mother and Child Health Centres in Oslo were randomly selected during 2016, and 175 lactating women between 2nd and 28th weeks postpartum participated. Each of the women provided four breastmilk samples which were pooled and analysed for iodine concentrations. Participants also provided information on iodine intake from food and supplements covering the last 24 h and the habitual iodine intake (food frequency questionnaire). The median (p25, p75 percentiles) BMIC was 68 (45, 98) µg/L and 76% had BMIC food (p25, p75) was 121 (82, 162) µg/day and the total intake (food and supplements) was 134 (95, 222) µg/day. The majority of lactating women had suboptimal BMIC and inadequate intake of iodine from food and supplements.

Measurement of thyroid volume, iodine concentration and total iodine content by CT and its clinical significance

International Nuclear Information System (INIS)

Nakaji, Shunsuke; Imanishi, Yoshimasa; Okamoto, Kyouko; Shinagawa, Toshihito

2007-01-01

Recently, Imanishi et al have developed new CT software for quantitative in vivo measurement of thyroid iodine. Using a CT system with the software, we measured volume, iodine concentration and total iodine content of thyroids in 63 controls and 435 patients with various diffuse thyroid diseases and thyroid nodules. In controls, all of them showed no difference between the sexes. Although the iodine concentration of the thyroid showed no difference among children, adults and seniles, the volume and total iodine content of the thyroid appeared smaller in children and seniles than in adults. In addition, although the volume and iodine concentration of the thyroid had two peaks in distribution, the total iodine content had almost normal distribution. Normal range of volume, iodine concentration and total iodine content in adults were 5.2-15.5 cm 3 , 0.28831-0.85919 mg/cm 3 and 2.35-11.69 mg, respectively. In thyroid nodule, there is no significant difference in volume, iodine concentration and total iodine content between benign and malignant nodules. All nodules with iodine concentration of less than 0.00007 mg/cm 3 were benign. No thyroid was higher in iodine concentration than the normal range although the thyroid was lower in 78.7% of patients with diffuse thyroid diseases. In all thyroids with increasing iodine concentration and total iodine content in medication course, thyroidal symptoms and signs were uncontrollable by the medication. In 43.8% of patients with long-period systemic diseases, the thyroid showed abnormality in any of the three. We concluded that quantitative in vivo measurement of thyroid iodine by CT could assist the diagnosis of thyroid diseases and decision of therapeutic methods. (author)

Models of iodine behavior in reactor containments

Energy Technology Data Exchange (ETDEWEB)

Weber, C.F.; Beahm, E.C.; Kress, T.S.

1992-10-01

Models are developed for many phenomena of interest concerning iodine behavior in reactor containments during severe accidents. Processes include speciation in both gas and liquid phases, reactions with surfaces, airborne aerosols, and other materials, and gas-liquid interface behavior. Although some models are largely empirical formulations, every effort has been made to construct mechanistic and rigorous descriptions of relevant chemical processes. All are based on actual experimental data generated at the Oak Ridge National Laboratory (ORNL) or elsewhere, and, hence, considerable data evaluation and parameter estimation are contained in this study. No application or encoding is attempted, but each model is stated in terms of rate processes, with the intention of allowing mechanistic simulation. Taken together, this collection of models represents a best estimate iodine behavior and transport in reactor accidents.

Models of iodine behavior in reactor containments

International Nuclear Information System (INIS)

Weber, C.F.; Beahm, E.C.; Kress, T.S.

1992-10-01

Models are developed for many phenomena of interest concerning iodine behavior in reactor containments during severe accidents. Processes include speciation in both gas and liquid phases, reactions with surfaces, airborne aerosols, and other materials, and gas-liquid interface behavior. Although some models are largely empirical formulations, every effort has been made to construct mechanistic and rigorous descriptions of relevant chemical processes. All are based on actual experimental data generated at the Oak Ridge National Laboratory (ORNL) or elsewhere, and, hence, considerable data evaluation and parameter estimation are contained in this study. No application or encoding is attempted, but each model is stated in terms of rate processes, with the intention of allowing mechanistic simulation. Taken together, this collection of models represents a best estimate iodine behavior and transport in reactor accidents

Pulsed electron-beam-sustained discharge in oxygen-containing gas mixtures: electrical characteristics, spectroscopy,and singlet oxygen yield

International Nuclear Information System (INIS)

Vagin, Nikolai P; Ionin, Andrei A; Klimachev, Yu M; Kotkov, A A; Podmar'kov, Yu P; Seleznev, L V; Sinitsyn, D V; Frolov, M P; Yuryshev, Nikolai N; Kochetov, Igor' V; Napartovich, A P; Hager, G D

2004-01-01

The electrical and spectroscopic characteristics of electron-beam-sustained discharge (EBSD) in oxygen and oxygen-containing gas mixtures are studied experimentally under gas pressures up to 100 Torr in a large excitation volume (∼18 L). It is shown that the EBSD in pure oxygen and its mixtures with inert gases is unstable and is characterised by a small specific energy contribution. The addition of small amounts (∼1%-10%) of carbon monoxide or hydrogen to oxygen or its mixtures with inert gases considerably improves the stability of the discharge, while the specific energy contribution W increases by more then an order of magnitude, achieving ∼6.5 kJ L -1 atm -1 per molecular component of the gas mixture. A part of the energy supplied to the EBSD is spent to excite vibrational levels of molecular additives. This was demonstrated experimentally by the initiation of a CO laser based on the O 2 : Ar : CO = 1 : 1 : 0.1 mixture. Experimental results on spectroscopy of the excited electronic states O 2 (a 1 Δ g ) and O 2 (b 1 Σ g + ), of oxygen formed in the EBSD are presented. A technique was worked out for measuring the concentration of singlet oxygen in the O 2 (a 1 Δ g ) state in the afterglow of the pulsed EBSD by comparing with the radiation intensity of singlet oxygen of a given concentration produced in a chemical generator. Preliminary measurements of the singlet-oxygen yield in the EBSD show that its value ∼3% for W ∼ 1.0 kJ L -1 atm -1 is in agreement with the theoretical estimate. Theoretical calculations performed for W ∼ 6.5 kJ L -1 atm -1 at a fixed temperature show that the singlet-oxygen yield may be ∼20%, which is higher than the value required to achieve the lasing threshold in an oxygen-iodine laser at room temperature. (laser applications and other topics in quantum electronics)

Nanostructured palladium tailored via carbonyl chemical route towards oxygen reduction reaction

International Nuclear Information System (INIS)

Luo, Y.; Mora-Hernández, J.M.; Estudillo-Wong, L.A.; Arce-Estrada, E.M.; Alonso-Vante, N.

2015-01-01

Graphical Abstract: Mass-depending morphologies of nanostructured Palladium obtained via the carbonyl chemical route. Display Omitted -- Highlights: •Mass-depending morphology was observed in nanostructured palladium supported on carbon prepared by the carbonyl chemical route. •The Morphological effect of carbon supported Pd was investigated towards ORR. -- Abstract: Carbon supported palladium nanostructures were synthesized via the carbonyl chemical route. Compared with nanostructured platinum, prepared via carbonyl chemical route, Pd nanomaterials showed mass-loading morphology, whereas particle size and morphology of Pt nanostructures was constant. The oxygen reduction reaction (ORR) on nanostructured Pd, with different morphology in both acid and alkaline medium was investigated. A relationship, based on X-ray diffraction structural analysis pattern, transmission electron microscope, with the Pd morphological effect on ORR activity was identified

Methodology for iodine-129 determination in coniferous plant by neutron activation

International Nuclear Information System (INIS)

Quintana, E.E.; Thyssen, S.M.

1998-01-01

Full text: The measurement methods of iodine-129 ( 129 I) include liquid scintillation counting, mass spectrometry analysis, X-ray spectrometry and neutron activation analysis. The combination of long half-life and low radiation energy, limit the sensitivity of a direct measurement in environmental matrixes. The neutron activation analysis (NAA) permits the increase in the sensitivity because of the high thermal neutron cross section of 129 I. The reaction produced is 129 I (n,γ) 130 I and the Eγ (536 keV) of iodine-130 (t 1/2 = 12,6 hours) is measured. The developed methodology allows the determination of 129 I in coniferous needles using NAA. The chemical treatment removes the interferences present in the matrix, as well as the Bromine-82 originated in the activation process. The analytical method is divided in six steps: a) digestion by alkaline fusion; b) radiochemical purification of 129 I by distillation followed by solvent extraction; c) distillation and adsorption on activated charcoal; d) neutron irradiation; e) radiochemical purification of 130 I by distillation followed by solvent extraction; f) gamma spectrometry. Iodine-131 tracer is added, and a chemical recovery of 95% in the distillations is obtained. The whole process recovery is within 70% and 85%. The detection limit is 0.48 mBq. Several factors affect this value, such as sample type, variety of coniferous, natural iodine concentration, irradiation time and neutron flux. (author) [es

Gas phase reactions of organic iodine in containment conditions

International Nuclear Information System (INIS)

Kaerkalae, T.; Holm, J.; Auvinen, A.; Zilliacus, R.; Kajolinna, T.; Tapper, U.; Gaenneskog, H.; Ekberg, C.

2010-01-01

In case of a hypothetical severe accident it is very likely that iodine at least partly deposits on painted walls of a reactor containment building. Iodine may react with painted surfaces to form organic iodine species. These organic species are a possible source of volatile iodine, which may increase the fraction of releasable iodine. Therefore, it is important to study the transport of organic iodine in containment conditions. Another question is, in which form are the organic iodides transported as gaseous molecules or as aerosol particles resulting from organic iodides reacting with radiolysis products. To answer this last question methyl iodide was fed into the EXSI facility in an air mixture. In some experiments the flow contained also humidity. The reactions took place in a quartz tube heated either to 50 deg. C, 90 deg. C or 120 deg. C. UV-light was used as a source of radiation to produce ozone from oxygen. A separate generator was also applied to reach higher ozone concentrations. Nucleated aerosol particles were collected on plane filters and gaseous iodine species were trapped in trapping bottles. Aerosol mass flow rate and size distribution as well as speciation of gaseous reaction products were measured with several on-line instruments. Collected aerosol particles were analysed with SEM. It was found that the formation of aerosol particles was very fast when ozone and methyl iodide were present in the facility. Even a very low concentration of ozone produced high number concentration of particles. The measured aerosol mass concentration increased with increasing temperature and ozone concentration. Because the particle diameter was quite small (<180 nm), their settling velocity is low. Therefore, iodine containing aerosols may exist in containment atmosphere for a long period of time. Part of methyl iodide was always transported through the facility regardless of experimental conditions. All ozone was consumed in the reactions when only UV-light was

Local radiolytic effectiveness of Auger electrons of iodine-125 in benzene-iodine solutions

International Nuclear Information System (INIS)

Uenak, P.; Uenak, T.

1987-01-01

High radiotoxicity of iodine-125 has been mainly attributed to the local radiolytic effects of Auger electrons on biological systems. In the present study, experimental and theoretical results are compared. The agreement between the experimental and theoretical results explains that the energy absorption of iodine aggregates has an important role in the radiolytic effectiveness of Auger electrons and iodine-125 in benzene-iodine solutions. (author) 18 refs.; 3 figs

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Schlegel, Michel L.; Mercier-Bion, Florence; Barre, Nicole; Reiller, Pascal; Moulin, Valerie

2006-01-01

The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L-3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine forming covalent bonds with organic molecules. Simulation of XANES spectra by linear combination of reference spectra suggested the predominance of iodine forming covalent bonds to aromatic rings (aromatic-bound iodine). Comparison of extended X-ray absorption fine structure (EXAFS) spectra of reference and samples further showed that iodine was surrounded by carbon shells at distances comparable to those for references containing aromatic-bound iodine. Quantitative analysis of EXAFS spectra indicated that iodine was bound to about one carbon at a distance d(I-C) of 2.01(4)-2.04(9) angstrom, which was comparable to the distances observed for aromatic-bound iodine in references (1.99(1)-2.07(6) angstrom), and significantly shorter than that observed for aliphatic-bound iodine (2.15(2)-2.16(2) angstrom). These results are in agreement with previous conclusions from X-ray photoelectron spectroscopy and from electro-spray ionization mass spectrometry. These results collectively suggest that the aromatic-bound iodine is stable in the various aquifers of this study. (authors)

Special syntheses of certain organic iodine compounds

International Nuclear Information System (INIS)

Henry, R.; Debuchy, D.; Junod, E.

1960-01-01

The technical difficulties encountered in working on radioactive products force us to choose the simplest methods of chemical synthesis possible. For iodine compounds, two special methods have been chosen: - by using fission recoil, we can prepare simple iodine compounds such as iodobenzene or methyl iodide in high yields and having a good degree of purity. The method consists in the irradiation of mixtures of uranium oxide and benzoic acid or ammonium acetate. The iodised product is separated by distillation, after dissolving the recoil medium in a solvent. - by isotopic exchange between the inorganic iodine of different valencies and complex molecules such as Bengal pink, and diodone, it is also possible to obtain satisfactory labelling yields. These reactions have been adapted so as to give a minimum time for isotopic exchange. In the case of Bengal pink, we have found a yield of 90 per cent after 60 minutes by exchange between Nal and the organic molecule in aqueous solution in presence of hydrogen peroxide. For diodone the method proposed by Liebster has been modified so as to reduce losses during purification. The analytical methods adopted for these different compounds are described. (author) [fr

Iodine nutritional status and thyroid effects of exposure to ethylenebisdithiocarbamates

Energy Technology Data Exchange (ETDEWEB)

Medda, Emanuela [National Centre for Epidemiology Surveillance and Health Promotion, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome (Italy); Santini, Ferruccio [Endocrinology Unit, Azienda Ospedaliero Universitaria Pisana, Pisa (Italy); De Angelis, Simona [Department of Cell Biology and Neuroscience, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome (Italy); Franzellin, Fabrizio [Nuclear Medicine of Bolzano Hospital, Bolzano (Italy); Fiumalbi, Carla [Department of Prevention, ASL Firenze (Italy); Perico, Andrea [Public Health Laboratory, ASL Firenze (Italy); Gilardi, Enzo [Department of Cell Biology and Neuroscience, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome (Italy); Mechi, Maria Teresa [Department of Prevention, ASL Firenze (Italy); Marsili, Alessandro [Endocrinology Unit, Azienda Ospedaliero Universitaria Pisana, Pisa (Italy); Citroni, Angela [Department of Prevention, ASL Firenze (Italy); Leandri, Adaniele [Public Health Laboratory, ASL Firenze (Italy); Mantovani, Alberto [Department of Food Safety and Veterinary Public Health, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome (Italy); Vitti, Paolo [Endocrinology Unit, Azienda Ospedaliero Universitaria Pisana, Pisa (Italy); Olivieri, Antonella, E-mail: antonella.olivieri@iss.it [Department of Cell Biology and Neuroscience, Italian National Institute of Health, Viale Regina Elena 299, 00161 Rome (Italy)

2017-04-15

Introduction: Italy is still characterized by a mild iodine deficiency and is among the most intensive users of chemical products for agriculture in Europe. The aim of this study was i) to evaluate thyroid effects of exposure to mancozeb, a fungicide widely used in agriculture, in a sample of Italian grapevine workers, and ii) to verify whether the iodine intake may modulate the risk of thyroid disruption due to the mancozeb metabolite ethylenthiourea (ETU). Methods: One hundred seventy-seven occupationally exposed male workers (29 from Chianti, a mild iodine deficient area, and 148 from Bolzano an iodine sufficient province) and 74 non-occupationally exposed male controls (34 from Chianti and 40 from Bolzano) were enrolled in the study. Serum biomarkers of thyroid function, as well as urinary iodine and ETU concentrations were assessed. Moreover all the recruited subjects underwent clinical examination and thyroid ultrasound. Results: Multivariate comparisons showed lower mean serum levels of FT4 in Chianti-workers as compared to Bolzano-workers. Moreover, an increased urinary iodine excretion (>250 µg/L) was more frequently found among more exposed workers (ETU>20 µg/L) than among less exposed ones and this effect was more pronounced in Chianti- than in Bolzano-workers. Chianti-workers also showed a significantly higher frequency of very low thyroid volume (≤6.0 ml) as compared to controls. Conclusions: These findings showed a mild thyroid disrupting effect due to occupational exposure to mancozeb, more pronounced in workers residing in an area characterized by a mild to moderate iodine deficiency as compared to workers residing in an area covered by a long-lasting iodine prophylaxis program. - Highlights: • Thyroid is vulnerable to endocrine disrupting effects due to environmental exposures. • Mancozeb is a fungicide widely used in agriculture worldwide. • Mancozeb is broken down into ethylenthiourea (ETU) which has anti-thyroid activity. • Iodine

Iodine nutritional status and thyroid effects of exposure to ethylenebisdithiocarbamates

International Nuclear Information System (INIS)

Medda, Emanuela; Santini, Ferruccio; De Angelis, Simona; Franzellin, Fabrizio; Fiumalbi, Carla; Perico, Andrea; Gilardi, Enzo; Mechi, Maria Teresa; Marsili, Alessandro; Citroni, Angela; Leandri, Adaniele; Mantovani, Alberto; Vitti, Paolo; Olivieri, Antonella

2017-01-01

Introduction: Italy is still characterized by a mild iodine deficiency and is among the most intensive users of chemical products for agriculture in Europe. The aim of this study was i) to evaluate thyroid effects of exposure to mancozeb, a fungicide widely used in agriculture, in a sample of Italian grapevine workers, and ii) to verify whether the iodine intake may modulate the risk of thyroid disruption due to the mancozeb metabolite ethylenthiourea (ETU). Methods: One hundred seventy-seven occupationally exposed male workers (29 from Chianti, a mild iodine deficient area, and 148 from Bolzano an iodine sufficient province) and 74 non-occupationally exposed male controls (34 from Chianti and 40 from Bolzano) were enrolled in the study. Serum biomarkers of thyroid function, as well as urinary iodine and ETU concentrations were assessed. Moreover all the recruited subjects underwent clinical examination and thyroid ultrasound. Results: Multivariate comparisons showed lower mean serum levels of FT4 in Chianti-workers as compared to Bolzano-workers. Moreover, an increased urinary iodine excretion (>250 µg/L) was more frequently found among more exposed workers (ETU>20 µg/L) than among less exposed ones and this effect was more pronounced in Chianti- than in Bolzano-workers. Chianti-workers also showed a significantly higher frequency of very low thyroid volume (≤6.0 ml) as compared to controls. Conclusions: These findings showed a mild thyroid disrupting effect due to occupational exposure to mancozeb, more pronounced in workers residing in an area characterized by a mild to moderate iodine deficiency as compared to workers residing in an area covered by a long-lasting iodine prophylaxis program. - Highlights: • Thyroid is vulnerable to endocrine disrupting effects due to environmental exposures. • Mancozeb is a fungicide widely used in agriculture worldwide. • Mancozeb is broken down into ethylenthiourea (ETU) which has anti-thyroid activity. • Iodine

Controversies in urinary iodine determinations

OpenAIRE

Soldin, Offie Porat

2002-01-01

Iodine deficiency (ID) is associated with increased prevalence of goiter, increased risk for neurodevelopmental disorders, and is the world’s leading cause of intellectual deficits. Iodine nutritional status of a population is assessed by measurements of urinary iodine concentrations which are also used to define, indicate, survey and monitor iodine deficiency and consequently its treatment. Several methods are available for urinary iodine determination. Discussed here are some of the limitat...

[The radioiodine test for the evaluation of iodine deficiency in the district of Karl-Marx-Stadt and in East Germany].

Science.gov (United States)

Bauch, K; Weiss, O; Möckel, G; Gerlach, J; Seitz, W; Ulrich, F E; Dempe, A

1981-10-01

The values of the per cent 24 h radioiodine uptake in the GDR are above 60--70% and speak for a low alimentary intake of iodine or renal excretion of iodine below 40 micrograms J/d. Like the struma prevalences they show a tendency increasing from north to south and characterize the whole European situation of iodine deficiency including its decrease from west to east. The mean values of radioiodine uptake of 71.7 +/- 13.2% (n = 110) in euthyroids of the district of Karl-Marx-Stadt correspond to the iodine deficiency as it occurs approximately in the districts of Erfurt, Dresden, Munich or Freiburg/B. The alimentary iodine intake of 38.4 +/- 17.2 micrograms J/d and the renal iodine excretion of 29.9 +/- 16.1 micrograms J/d, calculated from the 24 h radioiodine accumulation values of 40 euthyroid persons by means of a mathematical model developed by Oddie and co-workers were low. The latter only slightly differed (P less than 0.05) from its chemically estimated excretion of iodine in the urine: 23.1 +/- 16.9 micrograms J/g creatinine (n = 73). Between the calculated and chemically estimated excretion of iodine there was a relatively strict correlation of r = 0.68 (n = 26; P less than 0.001). The introduction of an iodine prophylaxis is regarded as an urgent necessity. Later on a new estimation of the regional "normal values" is necessary for the per cent radioiodine uptake.

A new kinetic model for human iodine metabolism

International Nuclear Information System (INIS)

Ficken, V.J.; Allen, E.W.; Adams, G.D.

1985-01-01

A new kinetic model of iodine metabolism incorporating preferential organification of tyrosil (TYR) residues of thyroglobulin is developed and evaluated for euthyroid (n=5) and hyperthyroid (n=11) subjects. Iodine and peripheral T4 metabolims were measured with oral /sup 131/I-NaI and intravenous /sup 125/I-74 respectively. Data (obtained over 10 days) and kinetic model are analyzed using the SAAM27 program developed by Berman (1978). Compartment rate constants (mean rate per hour +- ISD) are tabulated in this paper. Thyroid and renal iodide clearance compare favorably with values reported in the literature. TYR rate constants were not unique; however, values obtained are within the range of rate constants determined from the invitro data reported by others. Intraluminal iodine as coupled TYR is predicted to be 21% for euthyroid and 59% for hyperthyroid subjects compared to analytical chemical methods of 30% and 51% respectively determined elsewhere. The authors plan to evaluate this model as a method of predicting the thyroid radiation dose from orally administered I/sup 131/

Iodine adsorption on ion-exchange resins and activated carbons: batch testing

Energy Technology Data Exchange (ETDEWEB)

Parker, Kent E.; Golovich, Elizabeth C.; Wellman, Dawn M.

2014-09-30

Iodine sorption onto seven resins and six carbon materials was evaluated using water from well 299-W19-36 on the Hanford Site. These materials were tested using a range of solution-to-solid ratios. The test results are as follows. The efficacy of the resin and granular activated carbon materials was less than predicted based on manufacturers’ performance data. It is hypothesized that this is due to the differences in speciation previously determined for Hanford groundwater. The sorption of iodine is affected by the iodine species in the source water. Iodine loading on resins using source water ranged from 1.47 to 1.70 µg/g with the corresponding K_d values from 189.9 to 227.0 mL/g. The sorption values when the iodine is converted to iodide ranged from 2.75 to 5.90 µg/g with the corresponding K_d values from 536.3 to 2979.6 mL/g. It is recommended that methods to convert iodine to iodide be investigated in fiscal year (FY) 2015. The chemicals used to convert iodine to iodate adversely affected the sorption of iodine onto the carbon materials. Using as-received source water, loading and K_d values ranged from 1.47 to 1.70 µg/g and 189.8 to 226.3 mL/g respectively. After treatment, loading and K_d values could not be calculated because there was little change between the initial and final iodine concentration. It is recommended the cause of the decrease in iodine sorption be investigated in FY15. In direct support of CH2M HILL Plateau Remediation Company, Pacific Northwest National Laboratory has evaluated samples from within the 200W pump and treat bioreactors. As part of this analysis, pictures taken within the bioreactor reveal a precipitate that, based on physical properties and known aqueous chemistry, is hypothesized to be iron pyrite or chalcopyrite, which could affect iodine adsorption. It is recommended these materials be tested at different solution-to-solid ratios in FY15 to determine their effect on iodine

Iodine adsorption on ion-exchange resins and activated carbons: batch testing

International Nuclear Information System (INIS)

Parker, Kent E.; Golovich, Elizabeth C.; Wellman, Dawn M.

2014-01-01

Iodine sorption onto seven resins and six carbon materials was evaluated using water from well 299-W19-36 on the Hanford Site. These materials were tested using a range of solution-to-solid ratios. The test results are as follows. The efficacy of the resin and granular activated carbon materials was less than predicted based on manufacturers' performance data. It is hypothesized that this is due to the differences in speciation previously determined for Hanford groundwater. The sorption of iodine is affected by the iodine species in the source water. Iodine loading on resins using source water ranged from 1.47 to 1.70 µg/g with the corresponding K d values from 189.9 to 227.0 mL/g. The sorption values when the iodine is converted to iodide ranged from 2.75 to 5.90 µg/g with the corresponding K d values from 536.3 to 2979.6 mL/g. It is recommended that methods to convert iodine to iodide be investigated in fiscal year (FY) 2015. The chemicals used to convert iodine to iodate adversely affected the sorption of iodine onto the carbon materials. Using as-received source water, loading and K d values ranged from 1.47 to 1.70 µg/g and 189.8 to 226.3 mL/g respectively. After treatment, loading and K d values could not be calculated because there was little change between the initial and final iodine concentration. It is recommended the cause of the decrease in iodine sorption be investigated in FY15. In direct support of CH2M HILL Plateau Remediation Company, Pacific Northwest National Laboratory has evaluated samples from within the 200W pump and treat bioreactors. As part of this analysis, pictures taken within the bioreactor reveal a precipitate that, based on physical properties and known aqueous chemistry, is hypothesized to be iron pyrite or chalcopyrite, which could affect iodine adsorption. It is recommended these materials be tested at different solution-to-solid ratios in FY15 to determine their effect on iodine sorption.

A rechargeable iodine-carbon battery that exploits ion intercalation and iodine redox chemistry.

Science.gov (United States)

Lu, Ke; Hu, Ziyu; Ma, Jizhen; Ma, Houyi; Dai, Liming; Zhang, Jintao

2017-09-13

Graphitic carbons have been used as conductive supports for developing rechargeable batteries. However, the classic ion intercalation in graphitic carbon has yet to be coupled with extrinsic redox reactions to develop rechargeable batteries. Herein, we demonstrate the preparation of a free-standing, flexible nitrogen and phosphorus co-doped hierarchically porous graphitic carbon for iodine loading by pyrolysis of polyaniline coated cellulose wiper. We find that heteroatoms could provide additional defect sites for encapsulating iodine while the porous carbon skeleton facilitates redox reactions of iodine and ion intercalation. The combination of ion intercalation with redox reactions of iodine allows for developing rechargeable iodine-carbon batteries free from the unsafe lithium/sodium metals, and hence eliminates the long-standing safety issue. The unique architecture of the hierarchically porous graphitic carbon with heteroatom doping not only provides suitable spaces for both iodine encapsulation and cation intercalation but also generates efficient electronic and ionic transport pathways, thus leading to enhanced performance.Carbon-based electrodes able to intercalate Li + and Na + ions have been exploited for high performing energy storage devices. Here, the authors combine the ion intercalation properties of porous graphitic carbons with the redox chemistry of iodine to produce iodine-carbon batteries with high reversible capacities.

Effect of chronic douching with polyvinylpyrrolidone-iodine on iodine absorption and thyroid function

International Nuclear Information System (INIS)

Safran, M.; Braverman, L.E.

1982-01-01

Daily vaginal douching with polyvinylpyrrolidone-iodine in 12 euthyroid volunteers for 14 days resulted in a significant increase in serum total iodine concentration and urine iodine excretion. The increase in serum total iodine was associated with a marked decrease in 24-hour 123 I uptake by the thyroid and a small but significant increase in serum thyrotropin (TSH) concentration. However, values for serum TSH never rose above the normal range. No significant changes in serum thyroxine (T4), free T4 index (FTI), or triiodothyronine concentrations were observed, although serum T4 and FTI did decrease slightly during treatment. The findings suggest that iodine is absorbed across the vaginal mucosa and that the subsequent increase in serum total iodine does induce subtle increases in serum TSH concentration. There was no evidence, however, of overt hypothyroidism in these euthyroid women

Iodine tablets and a nuclear accident

International Nuclear Information System (INIS)

Paile, W.

1992-01-01

Radioactive iodine is one of the major substances released during severe nuclear accidents. Radioactive iodine is easily gasified, and if present in fallout it can enter the lungs, and thereby the circulatory system, with the inhalation of air. Once in a body, radioactive iodine accumulates in the thyroid and may result in tumours in the thyroid and, in extreme cases, impaired thyroid function. Accumulation of radioactive iodine can be prevented by taking non-radioactive, 'cold' iodine as tablets. Iodine tablets dilute the radioactive iodine that has entered the body. A dose of iodine also paralyses the thyroid temporarily by saturating its iodine-carrying capacity. To be useful iodine tablets should be taken immediately when a radioactive emission has occurred. If the tablets are taken too early or too late, they give little protection. Iodine tablets should not be taken just to be on the safe side, since their use may involve harmful side effects. Dosing instructions should also be followed with care. (orig.)

The interaction of iodine with organic material in containment

Energy Technology Data Exchange (ETDEWEB)

Wren, J C; Ball, J M; Glown, G A; Portmann, R; Sanipelli, G G [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1996-12-01

Organic impurities in containment water, originating from various painted structural surfaces and organic containment materials, could have a significant impact on iodine volatility following an accident. A research program has been designed to determine the impact of organic impurities on iodine volatility under accident conditions. The program consists of experimental, literature and modelling studies on the radiolysis or organic compounds in the aqueous phase, thermal and radiolytic formation and decomposition of organic iodides, dissolution of organic solvents from various painted surfaces into the aqueous phase, and iodine deposition on painted surfaces. The experimental studies consist of bench-scale `separate effects` tests as well as intermediate-scale `integrated effects` in the Radioiodine Test facility. The studies have shown that organic impurities will be found in containment water, arising from the dissolution of organic compounds from various surface paints and that these compounds can potentially have a significant impact on iodine volatility following an accident. The main impact of surface paints will occur through aqueous-phase reactions of the organic compounds that they release to the aqueous phase. Under the radiation conditions expected during an accident, these compounds will react to reduce the pH and dissolved oxygen concentration, consequently increasing the formation of I{sub 2} from I{sup -} that is present in the sump. It appears that the rates of these processes may be controlled by the dissolution kinetics of the organic compounds from the surface coatings. Moreover, the organic compounds may also react thermally and radiolytically with I{sub 2} to form organic iodides in the aqueous phase. Our studies have shown that the formation of organic iodides from soluble organics such as ketones, alcohols and phenols may have more impact on the total iodine volatility than the formation of CH{sub 3}I. (author) 13 figs., 2 tabs., 19 refs.

The interaction of iodine with organic material in containment

International Nuclear Information System (INIS)

Wren, J.C.; Ball, J.M.; Glown, G.A.; Portmann, R.; Sanipelli, G.G.

1996-01-01

Organic impurities in containment water, originating from various painted structural surfaces and organic containment materials, could have a significant impact on iodine volatility following an accident. A research program at the Whiteshell Laboratories of AECL has been designed to determine the impact of organic impurities on iodine volatility under accident conditions. The program consists of experimental, literature and modelling studies on the radiolysis or organic compounds in the aqueous phase, thermal and radiolytic formation and decomposition of organic iodides, dissolution of organic solvents from various painted surfaces into the aqueous phase, and iodine deposition on painted surfaces. The experimental studies consist of bench-scale 'separate effects' tests as well as intermediate-scale 'integrated effects' in the Radioiodine Test facility. The studies have shown that organic impurities will be found in containment water, arising from the dissolution of organic compounds from various surface paints and that these compounds can potentially have a significant impact on iodine volatility following an accident. The main impact of surface paints will occur through aqueous-phase reactions of the organic compounds that they release to the aqueous phase. Under the radiation conditions expected during an accident, these compounds will react to reduce the pH and dissolved oxygen concentration, consequently increasing the formation of I 2 from I - that is present in the sump. It appears that the rates of these processes may be controlled by the dissolution kinetics of the organic compounds from the surface coatings. Moreover, the organic compounds may also react thermally and radiolytically with I 2 to form organic iodides in the aqueous phase. Our studies have shown that the formation of organic iodides from soluble organics such as ketones, alcohols and phenols may have more impact on the total iodine volatility than the formation of CH 3 I. (author) 13 figs., 2

Iodine deficiency and nutrition in Scandinavia

DEFF Research Database (Denmark)

Manousou, Sofia; Dahl, Lisbeth; Heinsbaek Thuesen, Betina

2017-01-01

Iodine nutrition is a result of geological conditions, iodine fortification and monitoring strategies within a country together with the dietary habits of the population. This review summarizes the basis for the current iodine situation in the Scandinavian countries in order to identify gaps...... strategies have been used in Scandinavia to improve iodine nutrition. The major source of iodine is iodized salt in Sweden and from milk and dairy products in Norway. In Denmark, drinking water, milk, dairy products and iodized salt used in commercial production of bread are the important sources of iodine....... The current iodine status in Scandinavia is not optimal and action is ongoing to increase iodination in Denmark, where there is mild iodine deficiency in the general population. Data from all three countries indicate insufficient iodine nutrition during pregnancy and there is a need for data from children...

Iodine requirements and the risks and benefits of correcting iodine deficiency in populations

NARCIS (Netherlands)

Zimmermann, M.B.

2008-01-01

Iodine deficiency has multiple adverse effects on growth and development due to inadequate thyroid hormone production that are termed the iodine deficiency disorders (IDD). IDD remains the most common cause of preventable mental impairment worldwide. IDD assessment methods include urinary iodine

Volatilization of iodine from vegetation

International Nuclear Information System (INIS)

Amiro, B.D.; Johnston, F.L.

1989-01-01

Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na 125 I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author)

Volatilization of iodine from vegetation

Energy Technology Data Exchange (ETDEWEB)

Amiro, B D; Johnston, F L [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Nuclear Research Establishment

1989-01-01

Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na {sup 125}I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth media, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute < 0.1% to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere. (author).

The Status of Iodine Nutrition and Iodine Deficiency Disorders ...

African Journals Online (AJOL)

Background: Iodine deficiency disorders are serious public health problems in Ethiopia. The aim of this study was to measure the prevalence and severity of iodine deficiency disorders among school children in Metekel Zone. Methods: A cross-sectional school based descriptive study was conducted between February 2011 ...

Iodine filters in nuclear installations

International Nuclear Information System (INIS)

Wilhelm, J.G.

1982-01-01

The present report discusses the significance for environmental exposure of the iodine released with the gaseous effluents of nuclear power stations and reprocessing plants in relation to releases of other airborne radionuclides. Iodine filtration processes are described. The release pathways and the composition of airborne fission product iodine mixtures and their bearing on environmental exposure are discussed on the basis of measured fission product iodine emissions. The sorbents which can be used for iodine filtration, their removal efficiencies and range of applications are dealt with in detail. The particular conditions governing iodine removal, which are determined by the various gaseous iodine species, are illustrated on the basis of experimentally determined retention profiles. Particular attention is given to the limitations imposed by temperature, humidity, radiation and filter poisoning. The types of filter normally used are described, their advantages and drawbacks discussed, the principles underlying their design are outlined and the sources of error indicated. The methods normally applied to test the efficiency of various iodine sorbents are described and assessed. Operating experience with iodine filters, gathered from surveillance periods of many years, is supplemented by a large number of test results and the findings of extensive experiments. Possible ways of prolonging the permissible service lives of iodine filters are discussed and information is given on protective measures. The various iodine removal processes applied in reprocessing plants are described and compared with reference to efficiency and cost. The latest developments in filter technology in reprocessing plants are briefly outlined

EFEKTIFITAS SKELING-PENGHALUSAN AKAR DENGAN DAN TANPA APLIKASI SUBGINGIVAL POVIDON-IODIN 10% PADA POKET 5-7mm

Directory of Open Access Journals (Sweden)

Irma Ervina

2015-08-01

Full Text Available In deep periodontal lesions, scaling and root planning (SRP failed to complete elimination of periodontal bacteria, so chemical antimicrobial agents are used topically to destroy microorganism. Povidon-iodin 10% is one of antimicrobial agents that can be applied topically and directly in the pocket. The aim of the research were evaluated the efficacy of povidon-iodin 10% as chemical antimicrobial agents locally applied into periodontal pocket. The data are obtained from patients with chronic adult periodontitis, baseline periodontal pocket depth (PPD are 5-7 mm. The teeth are scaled and root planed after clinical examinations (plaque index, papilla bleeding index and periodontal pocket depth and test sites or control sites are assigned randomly. Topically application of povidon-iodin 10% at test sites and aquabides at control sites is applied at day 1st and day 7th. The clinical parameters are assessed at day 14th. The results of the research showed that application of povidon-iodin 10% after SRP provide statistically significant more favorable papilla bleeding index reduction than SRP + aquabides after 14 day. The pocket depth reduction at test sites are greater than control cites (baseline PPD=6 and 7 mm. The conclusions of the research showed that application subgingival povidon-iodin 10% as adjuctive to SRP significantly reduce PBI and PPD (6 & 7 mm than without application povidon-iodin 10%.

Breastfeeding and maternal and infant iodine nutrition.

Science.gov (United States)

Azizi, Fereidoun; Smyth, Peter

2009-05-01

The aim of this review is to explore information available regarding iodine secretion in milk, both mothers and infants iodine nutrition during breastfeeding and to make recommendations for appropriate iodine supplementation during lactation. MEDLINE was queried for studies between 1960 and 2007 that included lactation and breastfeeding with iodine and iodine deficiency. Studies were selected if they studied (i) Secretion of iodine in breast milk; (ii) breastfeeding and iodine nutrition; (iii) factors affecting maternal iodine metabolism and (iv) recommendations for iodine supplementation during breastfeeding. Thirty-six articles met the selection criteria. The iodine content of breast milk varies with dietary iodine intake, being lowest in areas of iodine deficiency with high prevalence of goitre. Milk iodine levels are correspondingly higher when programs of iodine prophylaxis such as salt iodization or administration of iodized oil have been introduced. The small iodine pool of the neonatal thyroid turns over very rapidly and is highly sensitive to variations in dietary iodine intake. Expression of the sodium iodide symporter is up-regulated in the lactating mammary gland which results in preferential uptake of iodide. In areas of iodine sufficiency breast milk iodine concentration should be in the range of 100-150 microg/dl. Studies from France, Germany, Belgium, Sweden, Spain, Italy, Denmark, Thailand and Zaire have shown breast milk concentrations of nutrition. The current WHO/ICCIDD/UNICEF recommendation for daily iodine intake (250 microg for lactating mothers) has been selected to ensure that iodine deficiency dose not occur in the postpartum period and that the iodine content of the milk is sufficient for the infant's iodine requirement.

Deposition velocity of gaseous organic iodine from the atmosphere to rice plants

International Nuclear Information System (INIS)

Muramatsu, Yasuyuki; Shigeo-Uchida; Sumiya, Misako; Ohmomo, Yoichiro

1996-01-01

To obtain parameter values for the assessment of 129 I transfer from the atmosphere to rice, deposition of CH 3 I to rice plants has been studied. The mass normalized deposition velocity (V D ) of CH 3 I for rough (unhulled) rice was 0.00048 cm 3 g -1 s -1 , which is about 1/300 of that of I 2 . Translocation of iodine, deposited as CH 3 I on leaves and stems, to rice grain was negligibly small. Distribution of iodine between hull and inner part of the grain was found to depend also on the chemical forms of atmospheric iodine to be deposited. The ratio of the iodine distribution in a grain exposed to CH 3 I was as follows: rough rice: brown rice (hulled rice):polished rice = 1.0:0.49:0.38. The distribution ratio in polished grains for CH 3 I exposed rice was about 20 times higher than that for I 2 . 22 refs., 1 fig., 6 tabs

CaMn0.875Ti0.125O3 as oxygen carrier for chemical-looping combustion with oxygen uncoupling (CLOU)—Experiments in a continuously operating fluidized-bed reactor system

KAUST Repository

Rydé n, Magnus; Lyngfelt, Anders; Mattisson, Tobias

2011-01-01

Particles of the perovskite material CaMn0.875Ti0.125O3 has been examined as oxygen carrier for chemical-looping with oxygen uncoupling, and for chemical-looping combustion of natural gas, by 70h of experiments in a circulating fluidized-bed reactor

Comparison of Iron and Tungsten Based Oxygen Carriers for Hydrogen Production Using Chemical Looping Reforming

Science.gov (United States)

Khan, M. N.; Shamim, T.

2017-08-01

Hydrogen production by using a three reactor chemical looping reforming (TRCLR) technology is an innovative and attractive process. Fossil fuels such as methane are the feedstocks used. This process is similar to a conventional steam-methane reforming but occurs in three steps utilizing an oxygen carrier. As the oxygen carrier plays an important role, its selection should be done carefully. In this study, two oxygen carrier materials of base metal iron (Fe) and tungsten (W) are analysed using a thermodynamic model of a three reactor chemical looping reforming plant in Aspen plus. The results indicate that iron oxide has moderate oxygen carrying capacity and is cheaper since it is abundantly available. In terms of hydrogen production efficiency, tungsten oxide gives 4% better efficiency than iron oxide. While in terms of electrical power efficiency, iron oxide gives 4.6% better results than tungsten oxide. Overall, a TRCLR system with iron oxide is 2.6% more efficient and is cost effective than the TRCLR system with tungsten oxide.

An Assessment of the Selenium Status of Iodine-Deficient and Non-Iodine Deficient Filipino Children

Directory of Open Access Journals (Sweden)

Ma. Sofia Amarra

2002-06-01

Full Text Available The aim of this study is to examine and compare blood selenium levels in iodine-deficient and non-iodine deficient children. Two groups of children were examined: one group with iodine deficiency (n=31 and the other group with normal iodine status (n=32. Blood was extracted by venipuncture from children aged 6-10 years attending first grade in Commonwealth Elementary School in Quezon City. Whole blood selenium was examined by electrothermal atomic absorption spectrophotometry (AAS. Iodine status was determined by goiter palpation and urinary iodine excretion. Mean selenium levels of deficient and non-deficient children were compared using T-test. Using a cut-off value of 60 mg Se/L whole blood, the proportion of children with normal and deficient iodine status who fell below this cut-off was compared using chi-square test. Whole blood selenium values ranged from 17.6 to 133.6 mg/L. There were no significant differences in mean selenium levels between children with normal and deficient iodine status. Children with normal iodine status had a mean blood selenium level of 55.87 ± 26.3 mg/L while children with deficient iodine status had a mean level of 58.76 ± 26.4 mg/L. Sixty percent of children had blood selenium levels below the arbitrary cut-off of 60 mg/L with no significant difference between groups (p = 0.165, indicating that selenium deficiency is prevalent in this group of children regardless of iodine status. Since selenium deficiency limits the response to iodine supplementation, further investigation is needed to determine whether the same situation exists in children from other areas.

A review of the radiation chemistry of iodine compounds in aqueous solution

International Nuclear Information System (INIS)

Sellers, R.M.

1977-06-01

Large amounts of radioactive iodine are formed in the fission of uranium in nuclear reactors. Some of this may be released to the coolant from the fuel either by diffusion through the canning material, or following the failure of a fuel pin. The iodine, which is released mainly as I 2 and methyl iodide, is transported with the coolant and, in direct cycle water cooled reactors, some is carried over with the steam to the turbines, where contamination may build up in the vicinity of steam leaks. Any assessment of the mechanism of the transport of iodine requires a knowledge of the relative amounts of the various oxidation states present, and must consider not only the thermal behaviour of iodine in water, but also the radiation chemical effects. A review is presented of the radiation chemistry of inorganic iodine compounds and methyl iodide in aqueous solutions. A number of unstable intermediates have been identified including species with iodide in valency states II, IV, VI and VIII. A considerable number of discrepancies exist in the literature data, and requirements for further work are identified. (author)

Iodine removal from a gas phase

International Nuclear Information System (INIS)

Vikis, A. Ch.

1982-01-01

Iodine, e.g. radioactive iodine, present as one or more organic iodides, optionally with elemental iodine, in a gas phase (e.g. air) are removed by photochemically decomposing the organic iodides to elemental iodine, reacting the iodine produced, and any initially present with excess ozone, preferably photochemically produced in situ in the gas phase to produce solid iodine oxides, and removing the solid oxides from the gas phase. (author)

Iodine removal from a gas phase

International Nuclear Information System (INIS)

Vikis, A.C.

1984-01-01

Iodine, e.g. radioactive iodine, present as one or more organic iodides, optionally with elemental iodine, in a gas phase (e.g. air) are removed by photochemically decomposing the organic iodides to elemental iodine, reacting the iodine produced, and any initially present with excess ozone, preferably photochemically produced in situ in the gas phase to produce solid iodine oxides, and removing the solid oxides from the gas phase

Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

Science.gov (United States)

Gong, Tingting; Zhang, Xiangru

2013-11-01

The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 μg/L as I for a 40 mL water sample (or 2.5 μg/L as I for an 80 mL water sample, or 1.25 μg/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared. Copyright © 2013 Elsevier Ltd. All rights reserved.

Oxidation Kinetics of Chemically Vapor-Deposited Silicon Carbide in Wet Oxygen

Science.gov (United States)

Opila, Elizabeth J.

1994-01-01

The oxidation kinetics of chemically vapor-deposited SiC in dry oxygen and wet oxygen (P(sub H2O) = 0.1 atm) at temperatures between 1200 C and 1400 C were monitored using thermogravimetric analysis. It was found that in a clean environment, 10% water vapor enhanced the oxidation kinetics of SiC only very slightly compared to rates found in dry oxygen. Oxidation kinetics were examined in terms of the Deal and Grove model for oxidation of silicon. It was found that in an environment containing even small amounts of impurities, such as high-purity Al2O3 reaction tubes containing 200 ppm Na, water vapor enhanced the transport of these impurities to the oxidation sample. Oxidation rates increased under these conditions presumably because of the formation of less protective sodium alumino-silicate scales.

Labelling aflatoxine-B1 by radioactive iodine

International Nuclear Information System (INIS)

Kim, Y.S.; Park, K.B.; Sung, H.K.; Ryu, Y.W.

1977-01-01

Labelling aflatoxines, the potential carcinogenic compounds, by radioactive iodine has been studied. The auflatoxine-B 1 , which is known to be the most abundant components of auflatoxines in the nature, was labelled by radioactive iodine-125 through an acid catalyst chloroamine-T procedure. The radiochemical yield was amounted to 63.6%. The chemical structure of the labelled product was proved to be 6-iodo 5-methoxy coumarine structure of auflatoxine-B 1 molecule by means of I.R. and N.M.R. spectroscopy. The labelled product was orally administered in a test animal (rat) and examined the accumulation of radioactivity in the body at the definite time interval. The accumulation of the radioactivity was pronounced at the blood and the liver. There was no indication of the decomposition of auflatoxine-B 1 - 125 I in the organs of the test animal. (author)

Performance of calcium manganate as oxygen carrier in chemical looping combustion of biochar in a 10 kW pilot

International Nuclear Information System (INIS)

Schmitz, Matthias; Linderholm, Carl Johan

2016-01-01

Highlights: • A manganese-based perovskite material was used as oxygen carrier in chemical looping combustion. • The oxygen carrier’s performance was superior to materials previously tested in this reactor throughout the testing period. • Under stable conditions, oxygen demand was as low as 2.1% with a carbon capture efficiency of up to 98%. • No signs of agglomeration were detected. • Gaseous oxygen was released at all relevant fuel reactor temperatures. - Abstract: Chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) are carbon capture technologies which achieve gas separation by means of cycling oxidation and reduction of a solid oxygen carrier. In this study, the performance and CLOU properties of an oxygen carrier with perovskite structure, CaMn_0_._9Mg_0_._1O_3_−_δ_, were investigated in a 10 kW pilot. The fuel consisted of biochar with very low sulphur content. Around 37 h of operation with fuel were carried out in the 10 kW chemical looping combustor. Previous operational experience in this unit has been achieved using different natural minerals as oxygen carrier – mainly ilmenite and manganese ore. Parametric studies performed in this work included variation of fuel flow, solids circulation rate, temperature and fluidization gas in the fuel reactor. The oxygen carrier was exposed to a total 73 h of hot fluidization (T > 600 °C). No hard particle agglomerations were formed during the experiments. An oxygen demand as low as 2.1% could be reached under stable operating conditions, with a carbon capture efficiency of up to 98%. CLOU properties were observed at all fuel reactor temperatures, ensuring stable operation even without steam as gasification agent present in the fuel reactor. The results suggest that CaMn_0_._9Mg_0_._1O_3_−_δ is suitable for the use as oxygen carrier in chemical looping combustion of solid biochar and offers higher gas conversion than previously tested materials without CLOU

Iodine speciation in the hot cell effluent gases

International Nuclear Information System (INIS)

Lee, B.S.; Jester, W.A.; Olynyk, J.M.

1990-01-01

The various species of airborne radioiodine can affect the iodine source term of a severe core damage accident because of the different transport and deposition properties. also, the radiobiological hazardness may vary according to their chemical form. The purpose of the work reported in this paper was to characterize the various chemical forms of airborne radioiodine in hot cell effluent gases of a radiopharmaceutical production facility that produces medical radioisotopes from separated fission products of irradiated uranium targets. It is concluded that the methyl iodide is the youngest chemical species in terms of effective decay time age, and the hot cell filter bank is least efficient in removing the methyl iodide

Effects of diuretics on iodine uptake in non-toxic goitre: comparison with low-iodine diet

Energy Technology Data Exchange (ETDEWEB)

Kapucu, L.Ozlem; Azizoglu, Firat [Department of Nuclear Medicine, Gazi University, Ankara (Turkey); Ayvaz, Goksun; Karakoc, Ayhan [Department of Endocrinology, Gazi University, Ankara (Turkey)

2003-09-01

Low-iodine diet has been employed to achieve iodine depletion prior to radioiodine (RI) therapy. However, treatment with diuretics may be more effective than low-iodine diet in causing iodine depletion and subsequent increase in RI uptake by the thyroid. Fifty-five patients with non-toxic goitre were given 0.20 MBq RI p.o. on the first day of the study and thyroid uptake was measured. In 15 patients, a low-iodine diet was started and continued for 14 days. The remaining 40 patients received furosemide 40 mg/day orally for 5 days with an unrestricted diet. On the 15th day of the study, all patients were given 0.20 MBq RI p.o. and thyroid RI uptake was measured again. Additionally, 24-h urinary iodine excretion and RI clearance were measured on the 1st and 6th days in 21 patients from the furosemide group and on the 1st and 15th days in eight patients from the diet group. Furosemide administration led to a 58.40% increase in iodine uptake over the baseline value, which was significantly higher than the increase caused by low-iodine diet (17.22%) (P<0.0001). Urinary excretion of RI decreased in both groups similarly (furosemide, 29.45%; low-iodine diet, 21.06%; P=0.33). Iodine clearance also decreased in each group similarly (10.61% vs 7.53%, P=0.53). Treatment with furosemide prior to administration of RI increases the uptake of RI by the thyroid more effectively than does low-iodine diet. (orig.)

Iodine content in bread and salt in Denmark after iodization and the influence on iodine intake

DEFF Research Database (Denmark)

Rasmussen, Lone Banke; Ovesen, Lars; Christensen, Tue

2007-01-01

Objective To measure the iodine content in bread and household salt in Denmark after mandatory iodine fortification was introduced and to estimate the increase in iodine intake due to the fortification. Design The iodine content in rye breads, wheat breads and salt samples was assessed. The incre......, and the current fortification level of salt ( 13 ppm) seems reasonable.......% of the rye breads and 90% of the wheat breads were iodized. The median iodine intake from bread increased by 25 ( 13-43) mu g/day and the total median iodine intake increased by 63 (36-104) mu g/day. Conclusions The fortification of bread and salt has resulted in a desirable increase in iodine intake...

Use of oxidative and reducing vapor generation for reducing the detection limits of iodine in biological samples by inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Vtorushina, Eh.A.; Saprykin, A.I.; Knapp, G.

2009-01-01

Procedures of microwave combustion in an oxygen flow and microwave acid decomposition of biological samples were optimized for the subsequent determination of iodine. A new method was proposed for the generation of molecular iodine from periodate iona using hydrogen peroxide as a reductant. Procedures were developed for determining iodine in biological samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) using oxidative and reducing vapor generation; these allowed the detection limit for iodine to be lowered by 3-4 orders of magnitude. The developed procedures were used to analyze certified reference materials of milk (Skim Milk Powder BCR 150) and seaweed (Sea Lettuce BCR 279) and a Supradyn vitamin complex

Iodine status in neonates in Denmark

DEFF Research Database (Denmark)

Nøhr, S B; Laurberg, Peter; Børlum, K G

1994-01-01

Iodine status of 147 neonates born in five different regions of Denmark was evaluated in relation to the iodine content of breast milk and iodine supplementation taken by the mother. Approximately two-thirds of the women had not received iodine supplementation. They had low iodine concentrations...... in breast milk and urinary iodine concentrations of the neonates at day 5 were low. The median values (milk/urine) were 33.6/31.7 micrograms/l (Randers 22/26, Ringkøbing 29/16, Aalborg 36/31. Arhus 54/41 and Copenhagen 55/59 micrograms/l). Higher values were found in the group where tablets containing...... iodine had been taken (milk/urine: 57.0/61.0 micrograms/l). In general, the values are low compared with internationally recommended levels. We suggest that mothers without autoimmune thyroid disease should receive iodine supplementation in the form of vitamin/mineral tablets containing iodine (150...

New methods of arene iodination and functional transformation of multiple bonds in organic compounds

International Nuclear Information System (INIS)

Filimonov, V.D.; Chajkovskij, V.K.; Krasnokutskaya, E.A.

2000-01-01

The review summarizes the latest results of organic chemistry and technology of organic synthesis department of Tomsk polytechnical university concerning iodination of arenes and chemical transformations of unsaturated compounds. Preparative possibilities of the new reactions and reagents for iodination, oxidation of alkenes and alkynes to 1,2- and bis-1,2-dicarbonyl compounds, iodonitration of alkynes, and reaction of oxidative dimerization of the terminal alkynes to unsaturated δ-sultones are discussed [ru

Chemical and Oxygen Isotopic Composition of Roman and Late Antique Glass from Northern Greece

Directory of Open Access Journals (Sweden)

Alberta Silvestri

2017-01-01

Full Text Available The present paper emphasizes the importance of measuring the oxygen isotopic and chemical compositions of ancient glass, in order to constrain some features such as age, raw materials, and production technologies and to identify the “fingerprint” of local productions. In this context, thirty-nine Roman and late Antique glass samples and eight chert samples from northern Greece were selected and analysed for their oxygen isotopic and chemical compositions. Results show that the majority of glass samples are produced using natron as flux and have δ18O values of about 15.5‰, plus or minus a few tenths of one per mil, suggesting that raw materials probably come from Levantine area. Four samples are heavily enriched in 18O, and their chemical composition clearly shows that they were made with soda plant ash as flux. Isotopic and chemical data of Greek chert samples support the hypothesis of local production of the above samples. About half of the glass samples have chemical compositions, which allow their age to be constrained to the late Antique period. For the remaining glass, similarities with literature compositional groups are reported and discussed.

Transition of Iodine Analysis to Accelerator Mass Spectrometry

International Nuclear Information System (INIS)

Watrous, Matthew George; Adamic, Mary Louise; Olson, John Eric; Baeck, D. L.; Fox, R. V.; Hahn, P. A.; Jenson, D. D.; Lister, T. E.

2015-01-01

The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world's best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

Transition of Iodine Analysis to Accelerator Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Watrous, Matthew George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adamic, Mary Louise [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, John Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baeck, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fox, R. V. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hahn, P. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jenson, D. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lister, T. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-01

The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world’s best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

Iodine Intakes of Victorian Schoolchildren Measured Using 24-h Urinary Iodine Excretion

Directory of Open Access Journals (Sweden)

Kelsey Beckford

2017-08-01

Full Text Available Mandatory fortification of bread with iodized salt was introduced in Australia in 2009, and studies using spot urine collections conducted post fortification indicate that Australian schoolchildren are now replete. However an accurate estimate of daily iodine intake utilizing 24-h urinary iodine excretion (UIE μg/day has not been reported and compared to the estimated average requirement (EAR. This study aimed to assess daily total iodine intake and status of a sample of primary schoolchildren using 24-h urine samples. Victorian primary school children provided 24-h urine samples between 2011 and 2013, from which urinary iodine concentration (UIC, μg/L and total iodine excretion (UIE, μg/day as an estimate of intake was determined. Valid 24-h urine samples were provided by 650 children, mean (SD age 9.3 (1.8 years (n = 359 boys. The mean UIE of 4–8 and 9–13 year olds was 94 (48 and 111 (57 μg/24-h, respectively, with 29% and 26% having a UIE below the age-specific EAR. The median (IQR UIC was 124 (83,172 μg/L, with 36% of participants having a UIC < 100 μg/L. This convenience sample of Victorian schoolchildren were found to be iodine replete, based on UIC and estimated iodine intakes derived from 24-h urine collections, confirming the findings of the Australian Health Survey.

Status of urinary iodine and I-131 uptake after universal iodination of common salt

International Nuclear Information System (INIS)

Alam, F.; Begum, F.; Haque, M.; Karim, M.A.; Faruque, O.; Ali, L.; Khan, A.K.A.

2002-01-01

This work was carried out in the Institute of Institute of Nuclear Medicine (INM), Bangabandhu Sheikh Mujib Medical University and Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, Dhaka. Here we have tried to explore present status of urinary iodine and uptake status in Bangabandhu. Period study was from 1998 to 2000. Total study population was 300, of them 84 was male and 216 was female. Populations of all social and economic strata have been studied, starting from bottoms to top-level income groups as well as urban, rural and suburban populations are included randomly. We studied I-131 uptake and urinary iodine. I-131 given orally in liquid form and the quantity accumulated by the thyroid gland at 24 hours intervals of time is measured using a gamma scintillation counter. Gamma-ray emission of 364 keV energy by I-131 is detected gamma scintillation counter. Urinary iodine is estimated by CIS-BIO kit. Urine is digested with chloric acid under mild conditions and determined manually by its catalytic role in the reduction of ceric ammonium sulfate in the presence of arsenious acid. The uptake was grouped into four categories according to their uptake percentage. Group-A; (lowest uptake group) 99 subject, have uptake between 0 to 4.9%, Group-B; 100 subjects, (relatively low uptake) who have uptake between 4.91-9.9%, group-C; 73 subjects, who have uptake between 10-30% and in-group D, there was 28 subjects their uptake was above 30%. We have also found in group-A median uptake is 3.0% and urinary iodine level is 43.31 μg/dl, in group-B median uptake is 7.0% and urinary iodine level is 33.95 μg/dl, in group-C median uptake is 23.0% and urinary iodine level is 12.97 μg/dl, in group-D median uptake is 34.0% and urinary iodine level is 9.35 μg/dl. We have found 1.04% have severe type low urinary iodine, 3.48% moderate type of low urinary iodine, 3.48%, 16.72% mild type of low urinary iodine and 78.74% have normal

Activation energies for iodine-exchange systems containing organic iodine compounds

Energy Technology Data Exchange (ETDEWEB)

Ikeda, N. (Takyo Univ. of Education (Japan). Faculty of Science) Takahashi, Yasuko

1976-01-01

In studies on the nonequilibrium isotopic exchange method for determining iodine in organic iodine compounds, activation energies have been measured to find systems having appropriate rate of exchange reactions. Activation energies are discussed by considering the effect of the structure of organic iodine compounds, the concentrations of reactants and solvent, etc. In homogeneous systems, activation energy is found to become larger in the order of CH/sub 3/Iiodine ratio between I/sub 2/ and organic iodine is a predominant factor in determining the rate of the exchange reaction.

Cea assessment of the sulphur-iodine cycle for hydrogen production

International Nuclear Information System (INIS)

Caries, Ph.; Vitart, X.; Yvon, P.

2010-01-01

The sulphur-iodine cycle is a promising process for hydrogen production using nuclear heat: - it is a purely thermochemical cycle, implying that hydrogen production will scale with volume rather than surface; - it only involves fluids, thus avoiding the often difficult handling of solids; - its heat requirements are well matched to the temperatures available from a Generation IV very/high temperature reactor. These characteristics seem very attractive for high efficiency and low cost massive hydrogen production. On the other hand, the efficiency of the cycle may suffer from the large over-stoichiometries of water and iodine and the very important heat exchanges it involves; furthermore, due to lack of adequate thermodynamic models, its efficiency is difficult to assess with confidence. Besides, the large quantities of chemicals that need to be handled, and the corrosiveness of these chemicals, are factors not to be overlooked in terms of investment and operation costs. In order to assess the actual potential of the sulphur-iodine cycle for massive hydrogen production at a competitive cost, CEA has been conducting an important programme on this cycle, ranging from thermodynamic measurements to hydrogen production cost evaluation, with flow sheet optimisation, component sizing and investment cost estimation as intermediate steps. The paper will present the method used, the status of both efficiency and production cost estimations, and discuss perspectives for improvement. (authors)

Iodine filters in nuclear power stations

International Nuclear Information System (INIS)

Wilhelm, J.G.

1977-04-01

On the basis of calculated and recorded release rates of nuclear power plants, the significance of iodine releases in the invironmental impact relative to other nuclides is discussed. The release pathways for iodine in LWR-type reactors and the efficiency of various methods to lower the activity release are given. The airborne species of iodine are discussed with regard to their removal in iodine sorption filters and environmental impact. The technical status of iodine removal by means of iodine sorption filters is studied for normal operation and accident conditions in nuclear power stations on the basis of the data given in the relevant literature for the efficiency of a number of iodine sorption materials. The applicability of concepts for ventilation and containment and their influence on iodine filter systems are discussed. Design, structure, and testing of iodine sorption filters are treated in detail; recommendations for design are given, and failure sources are mentioned. (orig.) [de

Growth of molybdenum disulphide using iodine as transport material

Indian Academy of Sciences (India)

In the present paper an attempt has been made to describe the chemical vapor transport (CVT) technique used for the growth of molybdenum disulphide (MoS2) single crystals. Iodine (I2) is used as transporting material for this purpose. The energy dispersive analysis by X-ray (EDAX) confirmed the stoichiometry of the ...

Long-term migration of iodine in sedimentary rocks based on iodine speciation and 129I/127I ratio

Science.gov (United States)

Togo, Y.; Takahashi, Y.; Amano, Y.; Matsuzaki, H.; Suzuki, Y.; Muramatsu, Y.; Iwatsuki, T.

2012-12-01

[Introduction] 129I is one of the available indexes of long-term migration of groundwater solutes, because of its long half-life (15.7 million years) and low sorption characteristics. The Horonobe underground research center (Japan Atomic Energy Agency), at which are conducted research and development of fundamental techniques on geological disposal of high-level radioactive waste, is an appropriate site for natural analogue studies, because iodine concentration in groundwater is high in this area. To predict iodine behavior in natural systems, speciation of iodine is essential because of different mobility among each species. In this study, we determined iodine speciation and129I/127I isotope ratios of rock and groundwater samples to investigate long term migration of iodine. [Methods] All rock and groundwater samples were collected at Horonobe underground research center. The region is underlain mainly by Neogene to Quaternary marine sedimentary rocks, the Wakkanai Formation (Wk Fm, siliceous mudstones), and the overlying Koetoi Formation (Kt Fm, diatomaceous mudstones). Iodine species in rock samples were determined by iodine K-edge X-ray absorption near edge structure (SPring-8 BL01B1). Thin sections of rock samples were prepared, and iodine mapping were obtained by micro-XRF analysis (SPring-8 BL37XU). Iodine species (IO3-, I-, and organic I) in groundwater were separately detected by high performance liquid chromatography connected to ICP-MS. The 129I/127I ratios in groundwater and rock samples were measured by accelerator mass spectrometry (MALT, Univ. of Tokyo). Iodine in rock samples were separated by pyrohydrolysis and water extraction. [Results and discussion] Concentration of iodine in groundwater varied widely and was much higher than that of seawater showing a high correlation with that of chlorine (R2 = 0.90). Species of iodine in groundwater was mainly I-. Iodine in rock samples decreased near the boundary between Wk and Kt Fms. Iodine K-edge XANES

Serum thyroglobulin and urinary iodine concentration are the most appropriate indicators of iodine status and thyroid function under conditions of increasing iodine supply in schoolchildren in Benin

NARCIS (Netherlands)

van den Briel, T.; West, C. E.; Hautvast, J. G.; Vulsma, T.; de Vijlder, J. J.; Ategbo, E. A.

2001-01-01

Iodine deficiency control programs have greatly reduced iodine deficiency disorders worldwide. For monitoring changes in iodine status, different indicators may be used. The aim of this study was to evaluate the suitability of indicators of iodine status and thyroid function, thyroglobulin (Tg),

Retrospective reconstruction of Iodine-131 distribution through the analysis of Iodine-129

Science.gov (United States)

Matsuzaki, Hiroyuki; Muramatsu, Yasuyuki; Ohno, Takeshi; Mao, Wei

2017-09-01

Iodine-131 distribution released from the Fukushima Dai-ichi Nuclear Power Plant accident was reconstructed through the iodine-129 measurements. From nearly 1,000 surface soil samples iodine was extracted by the pyro hydrolysis method. Extracted iodine was then mixed with carrier, purified and finally collected as silver iodide. Silver iodide sample was pressed into the cathode holder and set at the ion source of the MALT facility, The University of Tokyo. The isotopic ratio 129I/127I was measured by means of Accelerator Mass Spectrometry. From 129I data obtained, 131I deposition map was constructed. There observed various fine structures in the map which could not estimated neither by the simulation nor 137Cs distribution.

Thyroid disorders in mild iodine deficiency

DEFF Research Database (Denmark)

Laurberg, P; Nøhr, S B; Pedersen, K M

2000-01-01

Comparative epidemiologic studies in areas with low and high iodine intake and controlled studies of iodine supplementation have demonstrated that the major consequence of mild-to-moderate iodine deficiency for the health of the population is an extraordinarily high occurrence of hyperthyroidism...... endangered but the consequences of severe iodine deficiency for brain development are grave and a considerable safety margin is advisable. Moreover, a shift toward less malignant types of thyroid cancer and a lower radiation dose to the thyroid in case of nuclear fallout support that mild-to-moderate iodine...... deficiency should be corrected. However, there is evidence that a high iodine intake may be associated with more autoimmune hypothyroidism, and that Graves' disease may manifest at a younger age and be more difficult to treat. Hence, the iodine intake should be brought to a level at which iodine deficiency...

Iodine volatilization from irradiated CsI solutions

International Nuclear Information System (INIS)

Evans, G.J.; Panyan, E.J.

1996-01-01

A bench-scale, separate-effect, flow apparatus has been constructed to examine volatile iodine production rates in relation to a selection of the possible variables and conditions found in a containment structure with a breached reactor core. The constructed apparatus is designed to provide the widest possible range of data including gas and aqueous phase speciation for an established set of interfacial mass transfer parameters with known pH and dissolved oxygen levels. As the interfacial transfer of iodine is an important component in the understanding of iodine chemistry, commissioning of the constructed apparatus focused on establishing a well characterized set of mass transfer parameters for a variety of mixing conditions and solution volumes. Aqueous phase parameters, obtained using a method involving the sparging of the dissolved oxygen in the aqueous phase, were found to vary by one order of magnitude, from 1x10 -2 to 1x10 -3 dm/sec. Gas phase parameters also changeable by one order of magnitude, from 1x10 -1 to 1x10 -2 dm/sec, were studied more thoroughly as they were found to have a greater impact in the system. Two independent methods of analysis were used, one involving tri-iodide solutions, the other using relative humidity values. A selection of the acquired volatility rates in relation to the effect of pH are presented. The apparatus has been found to consistently provide rates up to one order of magnitude lower than modelled predictions. Specifically, for buffered solutions, rates of 2x10 -12 mol/min and 1x10 -10 mol/min for pH 9 and 5 respectively, have been found. Rates of 1x10 -11 mol/min and 6x10 -10 mol/min are predicted. Current efforts have addressed potential reasons for this apparent discrepancy, the major factor being the possible release of components from the stainless steel during irradiation. Efforts undertaken to ensure the validity of the results are emphasized. During commissioning efforts, several problems have been identified and

Epiboron instrumental neutron activation analysis for the determination of iodine in various salt samples

International Nuclear Information System (INIS)

Nyarko, B.J.B.; Serfor-Armah, Y.; Osae, S.; Akaho, E.H.K.; Anim-Sampong, S.; Maakuu, B.T.

2001-01-01

Epiboron instrumental neutron activation analysis (EINAA) using flexible boron as thermal neutron filter, has been used to analyze several salt samples obtained from various markets in Ghana for iodine. The method involves the irradiation of samples in boron carbide-lined polyethylene vials at the outer irradiation site of the Ghana Research Reactor-1 (GHARR-1). The samples were then counted directly without any pre-treatment on a Canberra N-type HPGe detector. The qualitative and quantitative analyses were done using the 443 keV photopeak of 128 I. The precision and accuracy of the method have been evaluated and the detection limits of the various samples were calculated. The values of iodine determined in the iodized salt range between 10.0 and 210 ppm. For non-iodinated salts, iodine levels were below 500 ppb. The values obtained show great variations among the salt samples, sample collection time and from market to market. This results show that the method can be successfully applied in the determination of trace amount of iodine in salt samples without any chemical separation. (author)

Transfer of gaseous iodine (I2) from atmosphere to rice grains through dry deposition

International Nuclear Information System (INIS)

Uchida, Shigeo; Muramatsu, Yasuyuki; Sumiya, Misako; Ohmomo, Yoichiro

1989-01-01

The report briefly outlines parameters required to determine the transfer of 129 I from the atmosphere to rice grains, and presents results of a study in which the transfer of iodine from the atmosphere to rice grains is calculated using empirically determined parameters. There are four major parameters required for the calculation: (1) the major transfer route (translocation either from leaves or from the surface of hulls to rice grains), (2) rate of deposition onto the surface of leaves or hulls, (3) biological half-life of iodine deposited on leaves or hulls, and (4) either the rate of translocation from leaves to hulls (where the translocation from leaves is the major route) or the ratio of iodine distribution among hulls, unpolished rice grains, and polished rice grains (where the translocation from hulls is the major route). Techniques available to determine the translocation route, deposition rate, biological half-life and distribution ratio are outlined. Chemical forms of iodine, parameters relating to the transfer of gaseous iodine to paddy rice, and calculation models are also described. (N,K.)

Assessing iodine intake, iodine status, and the effects of maternal iodine supplementation: introduction to articles arising from 3 workshops held by the NIH Office of Dietary Supplements12

Science.gov (United States)

Ershow, Abby G; Coates, Paul M; Swanson, Christine A

2016-01-01

The NIH Office of Dietary Supplements (ODS) convened 3 workshops on iodine nutrition in 2014, each held in Rockville, Maryland. These workshops were part of the ongoing ODS Iodine Initiative, begun in 2011 in response to concerns that US pregnant women may be at risk of iodine deficiency and that a high fraction of prenatal dietary supplements do not contain the recommended amounts of iodine. The primary purpose of the workshops was to consider the data and resources necessary to evaluate the clinical and public health benefits and risks of maternal iodine supplementation in the United States. The first workshop focused on the assessment of iodine intake, the second focused on the assessment of iodine status, and the third focused on the design and interpretation of clinical trials of maternal iodine supplementation. Here we provide the background of the ODS Iodine Initiative, summarize the 3 workshops held in 2014, and introduce the articles that arose from the workshops and are published in this supplement issue. PMID:27534646

Dietary Iodine Intake of the Australian Population after Introduction of a Mandatory Iodine Fortification Programme

Directory of Open Access Journals (Sweden)

Karen Charlton

2016-11-01

Full Text Available To address mild iodine deficiency in Australia, a mandatory fortification program of iodised salt in bread was implemented in 2009. This study aimed to determine factors associated with achieving an adequate dietary iodine intake in the Australian population post-fortification, and to assess whether bread consumption patterns affect iodine intake in high-risk groups. Using nationally representative data of repeated 24-h dietary recalls from the 2011–2012 Australian National Nutrition and Physical Activity Survey, dietary iodine intakes and food group contributions were compared by age, socioeconomic status (SES, and geographical remoteness (N = 7735. The association between fortified bread intake and adequacy of iodine intake (meeting age and sex-specific Estimated Average Requirements was investigated using logistic regression models in women of childbearing age 14–50 years (n = 3496 and children aged 2–18 years (n = 1772. The effect of SES on bread consumption was further investigated in a sub group of children aged 5–9 years (n = 488. Main sources of iodine intake at the time of the survey were cereal and cereal products, followed by milk products and dishes. Differences in iodine intake and dietary iodine habits according to age, SES and location were found (p < 0.001 for women of child-bearing age. Fortified bread consumption at ≥100 g/day was associated with five times greater odds of achieving an adequate iodine intake (OR 5.0, 95% CI 4.96–5.13; p < 0.001 compared to lower bread consumption in women and 12 times in children (OR 12.34, 95% CI 1.71–89.26; p < 0.001. Disparities in dietary iodine intake exist within sectors of the Australian population, even after mandatory fortification of a staple food. On-going monitoring and surveillance of iodine status is required.

Iodine-deficiency disorders

NARCIS (Netherlands)

Zimmermann, M.B.; Jooste, P.L.; Pandav, C.S.

2008-01-01

billion individuals worldwide have insufficient iodine intake, with those in south Asia and sub-Saharan Africa particularly affected. Iodine deficiency has many adverse effects on growth and development. These effects are due to inadequate production of thyroid hormone and are termed

Radioactive iodine absorbing properties of tetrathiafulvalene

Energy Technology Data Exchange (ETDEWEB)

Ito, Tomiyasu; Nakamura, Asao (Ajinomoto Co. Inc., Kawasaki, Kanagawa (Japan). Central Research Labs.); Nogawa, Norio; Oohashi, Kunio; Morikawa, Naotake

1989-05-01

For the purpose of searching some effective absorbents of gaseous radioactive iodine, 16 substances considered as having an affinity for iodine were investigated with regular iodine and /sup 125/I. In a preliminary survey, only tetrathiafulvalene (TTF) was found to have satisfactory absorbing properties comparable to activated charcoal. A further detailed comparison of the properties between TTF and activated charcoal led us to the conclusion that the former has more preferable properties as absorbent of radioactive iodine than the latter in all points studied. The results are summarized as follows: (1) The absorption of iodine on TTF in atmosphere was about twice as much as that on activated charcoal. Desorption of iodine from saturatedly absorbed iodine on TTF was practically negligible except trace amount of initial desorption, while that on activated charcoal was considerable (3%/50h) even in the air at room temperature. (2) Absorbed amount of iodine on activated charcoal decreased with increasing gaseous iodine concentration, air flow rate, on humidity of flowing-air. On the other hand, those factors scarcely affected that on TTF. Under an air flow rate of 1m/s, activated charcoal absorbs only 80% of iodine, while TTF absorbs more than 99%. (3) In flowing-air saturated with water vapor, iodine absorbed on activated charcoal was gradually liberated although by small amount (0.08%/100h), while that on TTF was much more stable for a long period (0.004%/100h). As a conclusion, TTF is considered to be useful as a quite effective radioactive iodine absorbent, especially in the case where protection from radioactive iodine should be serious, though it is expensive now. (author).

Radioactive iodine absorbing properties of tetrathiafulvalene

International Nuclear Information System (INIS)

Ito, Tomiyasu; Nakamura, Asao; Nogawa, Norio; Oohashi, Kunio; Morikawa, Naotake.

1989-01-01

For the purpose of searching some effective absorbents of gaseous radioactive iodine, 16 substances considered as having an affinity for iodine were investigated with regular iodine and 125 I. In a preliminary survey, only tetrathiafulvalene (TTF) was found to have satisfactory absorbing properties comparable to activated charcoal. A further detailed comparison of the properties between TTF and activated charcoal led us to the conclusion that the former has more preferable properties as absorbent of radioactive iodine than the latter in all points studied. The results are summarized as follows: (1) The absorption of iodine on TTF in atmosphere was about twice as much as that on activated charcoal. Desorption of iodine from saturatedly absorbed iodine on TTF was practically negligible except trace amount of initial desorption, while that on activated charcoal was considerable (3%/50h) even in the air at room temperature. (2) Absorbed amount of iodine on activated charcoal decreased with increasing gaseous iodine concentration, air flow rate, on humidity of flowing-air. On the other hand, those factors scarcely affected that on TTF. Under an air flow rate of 1m/s, activated charcoal absorbs only 80% of iodine, while TTF absorbs more than 99%. (3) In flowing-air saturated with water vapor, iodine absorbed on activated charcoal was gradually liberated although by small amount (0.08%/100h), while that on TTF was much more stable for a long period (0.004%/100h). As a conclusion, TTF is considered to be useful as a quite effective radioactive iodine absorbent, especially in the case where protection from radioactive iodine should be serious, though it is expensive now. (author)

Thyroid disorders in mild iodine deficiency.

Science.gov (United States)

Laurberg, P; Nøhr, S B; Pedersen, K M; Hreidarsson, A B; Andersen, S; Bülow Pedersen, I; Knudsen, N; Perrild, H; Jørgensen, T; Ovesen, L

2000-11-01

Comparative epidemiologic studies in areas with low and high iodine intake and controlled studies of iodine supplementation have demonstrated that the major consequence of mild-to-moderate iodine deficiency for the health of the population is an extraordinarily high occurrence of hyperthyroidism in elderly subjects, especially women, with risk of cardiac arrhythmias, osteoporosis, and muscle wasting. The hyperthyroidism is caused by autonomous nodular growth and function of the thyroid gland and it is accompanied by a high frequency of goiter. Pregnant women and small children are not immediately endangered but the consequences of severe iodine deficiency for brain development are grave and a considerable safety margin is advisable. Moreover, a shift toward less malignant types of thyroid cancer and a lower radiation dose to the thyroid in case of nuclear fallout support that mild-to-moderate iodine deficiency should be corrected. However, there is evidence that a high iodine intake may be associated with more autoimmune hypothyroidism, and that Graves' disease may manifest at a younger age and be more difficult to treat. Hence, the iodine intake should be brought to a level at which iodine deficiency disorders are avoided but not higher. Iodine supplementation programs should aim at relatively uniform iodine intake, avoiding deficient or excessive iodine intake in subpopulations. To adopt such a strategy, surveillance programs are needed.

Effects of strain rate, stress condition and environment on iodine embrittlement of Ziracloy-2

International Nuclear Information System (INIS)

Une, K.

1979-01-01

Iodine stress corrosion cracking (SCC) susceptibility of Zircaloy became higher with decreasing strain rate. Critical strain rate, below which high SCC severity was observed, substantially depended on Zircaloy stress condition. This strain rate (7 x 10 -3 min -1 ) under plane strain condition was about 3.5 times as fast as that (2 x 10 -3 min -1 ) under uniaxial condition. The maximum iodine embrittlement in Zircaloy was found in stress ratio α (axial/tangential stress) range of 0.5 to 0.7. No embrittlement occurred at α = infinity because of its texture effect. The SCC fracture stresses were about 39 kg/mm 2 for unirradiated and stress-relieved material, and about 34 kg/mm 2 for recrystallized material, whose ratios to yield strength of each material were 0.8 and 1.2. Impurity gases of oxygen and moisture in the iodine had the effects of reducing Zircaloy SCC susceptibility. Stress-relieved material was more sensitive to environmental impurities than recrystallized material

Iodine kinetics and effectiveness of stable iodine prophylaxis after intake of radioiodine: a review

International Nuclear Information System (INIS)

Geoffroy, B.; Verger, P.; Le Guen, B.

2000-01-01

Ingestion of stable iodine (potassium iodide) offers an efficient protection against the irradiation of the thyroid when an accidental exposure to radioiodine occurs. This prophylaxis aims at obtaining a rapid and maximum thyroid protection without antithyroid effects. This article reviews studies on iodine kinetics in the human and on stable iodine effectiveness to protect the thyroid. In adults with a normal thyroid function, ingestion of 100 mg of iodide just before exposure to radioiodine allows a percentage of thyroid averted dose equal or greater than 95%. If the exposure persists after iodide ingestion (100 mg), the percentage of averted dose may decrease significantly. Repeated ingestion of daily amounts of 15 mg of stable iodine would then allow to maintain a 90% effectiveness. Iodide effectiveness and antithyroid effects also depend on external and individual factors such as iodine amounts in the diet, thyroid function and age. It is recommended to adapt the amount of ingested stable iodine according to age at the time of exposure. (author)

Prophylactic iodine treatment in radiation protection

International Nuclear Information System (INIS)

Oberhausen, E.

1980-01-01

Prophylactic iodine treatment is to prevent accumulation of radioactive iodine in the thyroid. This is done by administering a large amount of stable iodine before uptake of radioactive iodine so that further accummulation of iodine in the thyroid will be impossible. This blocking effect should be as complete as possible. This is achieved by administering an initial dose of 200 mg potassium iodide. As the release of radioactive iodine may last several hours or even days; for this reason, maintenance doses of 100 mg potassium iodide should be administered in 8-hour intervals. The risk of prophylactiv iodine treatment is rather low; however, provocation of latent hyperthyreoses must be expected in, at the most, 0.2% of the exposed population. (orig./MG) [de

Iodine excretion in school children in Copenhagen

DEFF Research Database (Denmark)

Rasmussen, Lone B.; Kirkegaard-Klitbo, Ditte Marie; Laurberg, Peter

2016-01-01

INTRODUCTION: Studies of dietary habits show a high iodine intake in children in Denmark. Iodine excretion in children has not previously been assessed. Iodine excretion in adults is below the recommended threshold, and it is therefore being discussed to increase the fortification level. The main...... objective of this study was to assess iodine excretion in children living in Copenhagen to establish whether a moderate increase in iodine fortification would lead to excess iodine intake in this group. METHODS: Children in first and fifth grade were recruited through schools in Copenhagen. In total, 244...... children de-ivered a urine sample. Urine samples were analysed for iodine and creatinine, and the results were expressed as urinary iodine concentration (UIC) and as estimated 24-h iodine excretion. Iodine excretion in children was also compared with that of adults living in the same area, investigated...

Thyroid status and urinary iodine levels in women of endemic goiter area

International Nuclear Information System (INIS)

Bashir, S.; Shabbir, I.; Hussain, R.; Islam, M.U.; Aasim, M.

2012-01-01

Background: To determine the thyroid function tests and urinary iodine levels in women belonging to goiter endemic area. Study type and settings: Descriptive study conducted in women of goiter endemic area in Saggian Lahore. Subjects and Methods: Saggian Lahore is a goiter endemic area. A total of 293 women between the ages of 18-45 years residing in the area were clinically screened for goiter. Of them 73 women having goiter were recruited for the study. Information regarding demographic profile clinical presentation and physical examination of the goiter was recorded on a questionnaire. The goiter size was graded according to WHO, UNICEF and the International Council for the Control of Iodine Deficiency Disorder. About 5ml of blood sample was drawn from each women and run for thyroid function tests i.e. T3 T4 and TSH using Elisa kits (Human scientific Co. Germany). Urinary iodine was checked by chemical method. Results: Mean age of 73 women was 28.5 years. Marital status showed that 48(65.7%) were married and 25(34.3%) were unmarried. Visible diffuse goiter was seen in 56(77%) cases. Pressure symptoms as cough and shortness of breath was seen in 30(41%) and 31(42.5%) women respectively. Among the 73 women 24.6% (18 cases) took treatment for goiter. Adverse pregnancy outcome secondary to goiter was seen in 58% (28 cases) out of 48 married women. Thyroid function tests result showed that 72% (53 cases) were euthyroid, 18% (13 cases) were hypothyroid, and 10% (7 cases) were hyperthyroid. Urinary iodine levels showed that 99% women were iodine deficient. Conclusions: Thyroid functions do not indicate iodine deficiency in all cases of goiter, therefore, Urinary iodine levels need be estimated while investigating goiter cases. Policy message: Iodine deficiency should be diagnosed and treated on priority basis. (author)

Values of iodine metabolism biomarkers in assessing the iodine nutrition status in surgically treated patients with thyroid disease.

Science.gov (United States)

Han, Jian-hua; Wu, Lian; Yu, Song-lin; Fang, Hui-ling; Kamg, Wei-ming; Cheng, Xin-qi; Lu, Jie; Yu, Jian-chun; Qiu, Ling

2015-04-01

To assess the clinical application value of iodine metabolism biomarkers in assessing iodine nutrition status in surgically treated patients with thyroid disease. Blood,morning urine and 24-hour urine samples were collected in 31 healthy volunteers and in 30 surgically treated patients with thyroid disease before and after surgery. Iodine concentration was analyzed by inductively coupled plasma mass spectrometry. The iodine metabolism biomarkers including serum iodine (SI), morning urine iodine(UI), morning urine iodine/urine creatinine ratio (UI/UCr), 24-hour urine iodine (24 h UI), and 24-hour urine iodine excretion (24 h UIE) were evaluated in these two groups. In addition, the validation coincidence rate of iodine metabolism biomarkers in healthy volunteers to different reference ranges including World Health Organization, Mayo Clinic, and Quest Diagnostics were calculated. The UI/UCr ratio of pre-operative thyroid disease patients was significantly lower than that of healthy volunteers (P0.05) between these two groups. The SI, UI ,and 24 h UI in postoperative thyroid disease patients were significantly higher than those of the pre-operative patients (all Piodine metabolism biomarkers. The UI/UCr ratio may be used for iodine nutrition evaluation in surgically treated patients with thyroid disease.

Atomic resolution chemical bond analysis of oxygen in La2CuO4

Science.gov (United States)

Haruta, M.; Nagai, T.; Lugg, N. R.; Neish, M. J.; Nagao, M.; Kurashima, K.; Allen, L. J.; Mizoguchi, T.; Kimoto, K.

2013-08-01

The distorted CuO6 octahedron in La2CuO4 was studied using aberration-corrected scanning transmission electron microscopy at atomic resolution. The near-edge structure in the oxygen K-edge electron energy-loss spectrum was recorded as a function of the position of the electron probe. After background subtraction, the measured spectrum image was processed using a recently developed inversion process to remove the mixing of signals on the atomic columns due to elastic and thermal scattering. The spectra were then compared with first-principles band structure calculations based on the local-density approximation plus on-site Coulomb repulsion (LDA + U) approach. In this article, we describe in detail not only anisotropic chemical bonding of the oxygen 2p state with the Cu 3d state but also with the Cu 4p and La 5d/4f states. Furthermore, it was found that buckling of the CuO2 plane was also detectable at the atomic resolution oxygen K-edge. Lastly, it was found that the effects of core-hole in the O K-edge were strongly dependent on the nature of the local chemical bonding, in particular, whether it is ionic or covalent.

Rayleigh-type parametric chemical oscillation

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Shyamolina; Ray, Deb Shankar, E-mail: pcdsr@iacs.res.in [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

2015-09-28

We consider a nonlinear chemical dynamical system of two phase space variables in a stable steady state. When the system is driven by a time-dependent sinusoidal forcing of a suitable scaling parameter at a frequency twice the output frequency and the strength of perturbation exceeds a threshold, the system undergoes sustained Rayleigh-type periodic oscillation, wellknown for parametric oscillation in pipe organs and distinct from the usual forced quasiperiodic oscillation of a damped nonlinear system where the system is oscillatory even in absence of any external forcing. Our theoretical analysis of the parametric chemical oscillation is corroborated by full numerical simulation of two well known models of chemical dynamics, chlorite-iodine-malonic acid and iodine-clock reactions.

Rayleigh-type parametric chemical oscillation.

Science.gov (United States)

Ghosh, Shyamolina; Ray, Deb Shankar

2015-09-28

We consider a nonlinear chemical dynamical system of two phase space variables in a stable steady state. When the system is driven by a time-dependent sinusoidal forcing of a suitable scaling parameter at a frequency twice the output frequency and the strength of perturbation exceeds a threshold, the system undergoes sustained Rayleigh-type periodic oscillation, wellknown for parametric oscillation in pipe organs and distinct from the usual forced quasiperiodic oscillation of a damped nonlinear system where the system is oscillatory even in absence of any external forcing. Our theoretical analysis of the parametric chemical oscillation is corroborated by full numerical simulation of two well known models of chemical dynamics, chlorite-iodine-malonic acid and iodine-clock reactions.

Longitudinal study of iodine in toenails following IV administration of an iodine-containing contrast agent

International Nuclear Information System (INIS)

Spate, V.L.; Morris, J.S.; Nichols, T.A.; Baskett, C.K.; Mason, M.M.; Horsman, T.L.; McDougall, I.R.

1998-01-01

The literature on the relationship between diet and thyroid cancer (TC) risk and the higher incidence of TC among Asian immigrants to the US compared to second and third generation subgroups has prompted epidemiologists to hypothesize that increased levels of iodine consumption may be associated with TC risk, particularly among persons with a history of clinical or subclinical thyroid dysfunction. At the University of Missouri Research Reactor (MURR), we have applied epiboron neutron activation analysis to investigate human nails as a dietary monitor for iodine. Preliminary studies have indicated a positive correlation between dietary iodine intake and the concentration of iodine in toenails. However, these studies are confounded by high iodine levels (up to 30 ppm) in approximately 5% of the nails studied. We hypothesize that, in the subjects we have studied, the high iodine levels may be due to iodine-containing medications, in particular contrast-agents containing iopamidol. This paper will report on longitudinal studies using contrast agent subjects who where followed-up for almost two years compared to a longitudinal control and a population mean. Based on this study, we suggest that iodine-containing contrast agents contaminate nail samples via non-specific binding in the short term followed by incorporation in the nail as a result of absorption. (author)

Study on adsorption performance of coal based activated carbon to radioactive iodine and stable iodine

International Nuclear Information System (INIS)

Zhou, Junbo; Hao, Shan; Gao, Liping; Zhang, Youchen

2014-01-01

Highlights: • The impregnated coal-based activated carbons as adsorbent for removing methyl iodide. • The coal-based activated carbons to remove stable iodine. • Iodine residues are under 0.5 μg/ml after adsorption treatment. • The decontamination factor is much higher than 1000. - Abstract: Nuclear power plant, nuclear reactors and nuclear powered ship exhaust contains a large amount of gaseous radioactive iodine, and can damage to the workplace and the surrounding environment. The quantitative test to remove methyl iodide and the qualitative test for removing stable iodine were investigated using the impregnated coal-based activated carbons and coal-based activated carbons as adsorbents. The research conducted in this work shows that iodine residues were under 0.5 μg/ml after adsorption treatment and the decontamination factor of the coal-based activated carbon for removing the stable iodine was more than 1000, which can achieve the purpose of removing harmful iodine, and satisfy the requirement of gaseous waste treatment of nuclear powered vessel and other nuclear plants

Adsorption and revaporisation studies of thin iodine oxide and CsI aerosol deposits from containment surface materials in LWRs

Energy Technology Data Exchange (ETDEWEB)

Tietze, S.; Foreman, M.; Ekberg, C. [Chalmers Univ. of Technology, Goeteborg (Sweden); Kaerkelae, T.; Auvinen, A.; Tapper, U.; Jokiniemi, J. [VTT Technical Research Centre of Finland, Espoo (Finland)

2013-07-15

During a severe nuclear accident released fission and radiolysis products can react with each other to form new species which might contribute to the volatile source term. Iodine will be released from UO2 fuel mainly in form as CsI aerosol particles and elemental iodine. Elemental iodine can react in gaseous phase with ozone to form solid iodine oxide aerosol particles (IOx). Within the AIAS-2 (Adsorption of Iodine Aerosols on Surfaces) project the interactions of IOx and CsI aerosols with common containment surface materials was investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS. Non-radioactive and {sup 131}I labelled aerosols were produced from a KI solution and ozone with a new facility designed and built at VTT Technical Research Centre of Finland. CsI aerosols were produced from a CsI solution with the same facility. A monolayer of the aerosols was deposited on the surfaces. The deposits were analysed with microscopic and spectroscopic measurement techniques to identify the chemical form of the deposits on the surfaces to identify if a chemical conversion on the different surface materials had occured. The revaporisation behaviour of the deposited aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 with a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The decomposition effect of the radiolysis product carbon monoxide was tested on IOx aerosols deposited on a glass fibre filter. Iodine oxide particles were produced at 50 deg. C, 100 deg. C and 120 deg. C and deposited on filter samples in order to study the chemical

Adsorption and revaporisation studies of thin iodine oxide and CsI aerosol deposits from containment surface materials in LWRs

International Nuclear Information System (INIS)

Tietze, S.; Foreman, M.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.; Tapper, U.; Jokiniemi, J.

2013-07-01

During a severe nuclear accident released fission and radiolysis products can react with each other to form new species which might contribute to the volatile source term. Iodine will be released from UO2 fuel mainly in form as CsI aerosol particles and elemental iodine. Elemental iodine can react in gaseous phase with ozone to form solid iodine oxide aerosol particles (IOx). Within the AIAS-2 (Adsorption of Iodine Aerosols on Surfaces) project the interactions of IOx and CsI aerosols with common containment surface materials was investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS. Non-radioactive and 131 I labelled aerosols were produced from a KI solution and ozone with a new facility designed and built at VTT Technical Research Centre of Finland. CsI aerosols were produced from a CsI solution with the same facility. A monolayer of the aerosols was deposited on the surfaces. The deposits were analysed with microscopic and spectroscopic measurement techniques to identify the chemical form of the deposits on the surfaces to identify if a chemical conversion on the different surface materials had occured. The revaporisation behaviour of the deposited aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 with a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The decomposition effect of the radiolysis product carbon monoxide was tested on IOx aerosols deposited on a glass fibre filter. Iodine oxide particles were produced at 50 deg. C, 100 deg. C and 120 deg. C and deposited on filter samples in order to study the chemical speciation of

The speciation of iodine in the environment

International Nuclear Information System (INIS)

Bulman, R.A.

1986-01-01

The speciation of iodine in the environment is discussed under the following topics: (i) sea surface to atmosphere, (ii) chemistry in bulk seawater, (iii) iodine in rocks, (iv) iodine in soils, (v) iodine in plants and (vi) iodine in solidified wastes. (author)

Oxygen-vacancy defects on BaTiO3 (001) surface: a quantum chemical study

International Nuclear Information System (INIS)

Duque, Carlos; Stashans, Arvids

2003-01-01

A quantum-chemical study of technologically important BaTiO 3 crystal and oxygen-vacancy defects on its (001) surface is reported in the present work. The computations are made using a quantum-chemical method developed for periodic systems (crystals), which is based on the Hartree-Fock theory. The atomic rearrangement due to the surface creation is obtained for a pure BaTiO 3 by means of the periodic large unit cell (LUC) model and using an automated geometry optimisation procedure. The same technique is employed to study the electronic and structural properties of the material due to the presence of an O vacancy and F centre (two electrons trapped in an oxygen vacancy). The computations are carried out for both cubic and tetragonal lattices

Iodine deficiency in pregnancy in Denmark. Regional variations and frequency of individual iodine supplementation

DEFF Research Database (Denmark)

Nøhr, S B; Laurberg, Peter; Børlum, K G

1993-01-01

Iodine requirements are increased during pregnancy and lactation and adequate iodine intake is important for normal brain development of the fetus/newborn child. The aim of the present study was to evaluate the extent to which this increase in iodine requirement is met in pregnant women living...... micrograms/g creatinine). These values are far below internationally recommended levels. The consequences remain to be evaluated and no firm recommendations can be given. It seems reasonable, however, to recommend a high intake of food containing iodine (e.g. milk products) during pregnancy and lactation...

Iodine deficiency in pregnancy in Denmark. Regional variations and frequency of individual iodine supplementation

DEFF Research Database (Denmark)

Nøhr, S B; Laurberg, P; Børlum, K G

1993-01-01

micrograms/g creatinine). These values are far below internationally recommended levels. The consequences remain to be evaluated and no firm recommendations can be given. It seems reasonable, however, to recommend a high intake of food containing iodine (e.g. milk products) during pregnancy and lactation...... containing vitamin/mineral tablets. Approximately one third of the women had received tablets containing iodine. In women who had not received iodine supplementation urinary iodine was low with a median value of 39.7 micrograms/g creatinine (Aalborg 28, Randers 33, Ringkøbing 34, Arhus 43 and Copenhagen 62...

Effect of iodine solutions on polyaniline films

International Nuclear Information System (INIS)

Ayad, M.M.; Amer, W.A.; Stejskal, J.

2009-01-01

Polyaniline (PANI) emeraldine-base films have been exposed to iodine solutions. The interaction between the films and the iodine solution was studied using the quartz-crystal microbalance (QCM) technique and the UV-visible absorption spectroscopy. The iodine-treated film of emeraldine base was subjected to dedoping process using 0.1 M ammonia solution. The resulting film was exposed again to the previously used iodine solution. Iodine was found to play multiple roles: the ring-iodination of PANI film, the oxidation of PANI to pernigraniline base, and iodine doping to PANI salt. A sensor based on PANI-coated electrode of QCM was developed to monitor the presence of iodine in solution.

Influence of iodine chemistry on source term assessment

International Nuclear Information System (INIS)

Herranz Puebla, L. E.; Lopez Diez, I.; Rodriguez Maroto, J. J.; Martinez Lopez-Alcorocho, A.

1991-01-01

The major goal of a phenomenology analysis of containment during a severe accident situation can be spitted into the following ones: to know the containment response to the different loads and to predict accurately the fission product and aerosol behavior. In this report, the main results coming from the study of a hypothetical accident scenario, based on LA-4 experiment of LACE project, are presented. In order to do it, several codes have been coupled: CONTEMPT4/MOD5 (thermohydraulics), NAUA/MOD5 (aerosol physics) and IODE (iodine chemistry). It has been demonstrated the impossibility of assessing with confidence the Source Term if the chemical conduct of some radionuclides is not taken into account. In particular, the influence on the iodine retention efficiency of the sump of variables such as pH has been proven. (Author)12 refs

Electrochemistry of iodine

Energy Technology Data Exchange (ETDEWEB)

Yaraliev, Ya.A. (AN Azerbajdzhanskoj SSR, Baku. Inst. Neorganicheskoj i Fizicheskoj Khimii)

1982-06-01

The review is devoted to investigations into oxidation-reduction processes in different systems including iodine. The data on adsorption of iodine on metals are discussed; the connection between the nature of iodine adsorption and the mechanism of its electrode reactions is considered. The metals studied can be placed in the following series taking into account the degree of I sorption on them: Cd approximately Tl < Sn approximately Pb < Ga < Bi < Hg < Co approximately Ni < Fe < Ag approximately Rh approximately Pd approximately Ir < Pt. The data are given of standard and equilibrium potentials in iodine systems. Electric oxidation and electric reduction of iodide ions is investigated using the methods of Faraday impedance and rectification, methods of voltamperometry and oscillopolarography, rotating disc electrode, chronopotentiometry. Anode and cathode processes of oxidation-reduction reactions in I/sup -//IO/sub 3//sup -/, I/sub 2//IO/sub 3//sup -/ and I/sub 2//I/sup +/ systems are analyzed.

Iodine-131 production by a dry method using reactor-irradiated elementary tellurium. Part 1 - Conditions for obtaining iodine emanation and its capture. Part 2 - comparative study of preparation conditions using Pyrex, stainless steel and alumina equipment. Part 3 - production on a semi-industrial scale; Production de l'iode 131 par voie seche a partir de tellure elementaire irradie a la pile. 1ere partie - Etudes des conditions pour obtenir l'emanation de l'iode et le capter. 2eme partie - Etude comparee des conditions pour effectuer cette preparation avec des appareils en Pyrex, en acier inoxydable et en alumine. 3eme partie - production a l'echelle semi-industrielle

Energy Technology Data Exchange (ETDEWEB)

Bardy, A; Beydon, J; Murthy, T S; Doyen, J B; Lefrancois, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-04-15

A previous report has described how iodine 131 can be prepared from elementary tellurium by a dry method which consists in treating irradiated tellurium at 400 degrees in argon. The possibility of carrying out this treatment in a stainless steel or alumina apparatus has been considered. The behavior of gaseous iodine 131 towards these materials has thus been studied. If the adsorption of iodine on stainless steel is superficial desorption is rapid at 250 degrees in oxygen or 400 degrees in argon. If the adsorption is chemical in nature it becomes necessary to heat to higher temperatures. Adsorption of iodine on alumina is very weak and the iodine can be desorbed rapidly. With these materials tests have been carried out on 300 gms of tellurium containing 41 curies of iodine 131; the yields were very satisfactory ( 98 per cent). (author) [French] La methode de preparation de l iode 131 par voie seche a partir de tellure elementaire decrite dans un precedent rapport consiste a traiter le tellure irradie a 400 degres sous argon. Nous avons examine la possibilite d effectuer ce traitement dans un appareil en acier inoxidable ou en alumine. Le comportement de l iode 131 gazeux vis a vis de ces materiaux a donc ete etudie. Si l adsorption de l iode sur l acier inoxidable est superficielle la desorption est rapide a 250 degres sous oxygene ou 400 degres sous argon. Si la fixation est de nature chimique il est necessaire de chauffer a des temperatures plus elevees. L adsorption de l iode sur l alumine est res faible et l iode peut etre desorbe rapideemnt. En employant ces materiaux des essais ont ete obtenus sur 300 g de tellure contenant 41 curies d iode 131 avec un bon rendement (98 pour cent). (auteur00.

Study on iodine levels in thyroids of iodine-supplemented rats by epithermal neutron activation analysis

International Nuclear Information System (INIS)

Wang Xuefei; Zhang Fang; Xu Qing; Liu Nianqing; Chai Zhifang; Zhao Xueqin; Zuo Aijun

2003-01-01

The second generation female Wistar rats that have been treated with iodine-deficient food, after their delivery, are divided into three groups i.e. excessive-iodine (EI), adequate-iodine (AI) and iodine-deficient (ID) according to the KIO 3 concentration in the drinking water (3.0, 0.4, 0 mg/L). In addition, the normal rats with low iodine food and 0.4 mg/L KIO 3 water are used as the control group (C). The iodine content in thyroid and the serum thyroid hormone levels of the third generation rats are measured by means of epithermal neutron activation analysis (ENAA), and the method of enzyme-linked immunosorbent assay (ELISA), respectively. The results indicate that the total thyroxine (TT 4 ) and the free thyroxine (FT 4 ) of the EI, compared with those of the controls, are significantly decreased (p 3 ) evidently increased (p 4 , FT 4 and goiter

Iodine excretion has decreased in Denmark between 2004 and 2010 - the importance of iodine content in milk

DEFF Research Database (Denmark)

Rasmussen, Lone Banke; Carlé, Allan; Jørgensen, Torben

2014-01-01

Fortification with the essential trace element iodine is widespread worldwide. In the present study, results on iodine excretion and intake of iodine-rich foods from a cross-sectional study carried out in 2004-5, 4 to 5 years after the implementation of mandatory iodine fortification, were compared...... with data in a study carried out in 2008-10. The 2008-10 study was a follow-up of a cross-sectional study carried out before iodine fortification was implemented. Participants in the cross-sectional studies were randomly selected. Both studies were carried out in the cities of Aalborg and Copenhagen...... in Denmark. The median urinary iodine concentration decreased in women from 97 μg/l (n 2862) to 78 μg/l (n 2041) (Piodine excretion. The prevalence of users of iodine containing dietary...

Separation and retention of iodine

International Nuclear Information System (INIS)

Thomas, T.R.

1976-01-01

Caustic and mercuric nitrate scrubbers have been used for iodine recovery from process offgas, but they exhibit low decontamination factors for organic iodide removal and produce liquid wastes that are unsuitable for final storage. The Iodox process gives high decontamination factors for both organic iodides and elemental iodine. The liquid waste can be evaporated to a solid or concentrated and fixed in cement. Efficient separation and retention of gaseous iodine species can be obtained with silver-loaded adsorbents. The waste is a dry solid easily handled and stored. Adsorbents containing cheaper metals appear to have lower iodine-loading capacities and may be unsuitable for bulk iodine removal from process offgas because of the large amounts of solid waste that would be generated. A potential method for regenerationg and recycling silver-loaded adsorbents is being evaluated. In conjunction with the regeneration, lead-exchanged zeolite is used as a secondary adsorbent for the final fixation and storage of the iodine

Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds

KAUST Repository

Wang, Zhandong

2017-11-28

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500–600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound’s molecular structure (n-alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.

Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds

KAUST Repository

Wang, Zhandong; Popolan-Vaida, Denisia M.; Chen, Bingjie; Moshammer, Kai; Mohamed, Samah; Wang, Heng; Sioud, Salim; Raji, Misjudeen; Kohse-Hö inghaus, Katharina; Hansen, Nils; Dagaut, Philippe; Leone, Stephen R.; Sarathy, Mani

2017-01-01

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500–600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound’s molecular structure (n-alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.

The importance of iodine nutrition during pregnancy.

Science.gov (United States)

Glinoer, Daniel

2007-12-01

To examine the importance of iodine nutrition during pregnancy. Review of existing literature of iodine in pregnancy. Population surveys and metabolic studies. Pregnant women. The main changes in thyroid function associated with pregnancy are due to an increase in hormone requirements that begin in the first trimester of gestation. This increase can only be met by a proportional increase in hormone production, something that depends directly upon the availability of iodine. When dietary iodine is lacking, an adequate physiological adaptation is difficult to achieve and is progressively replaced by pathological alterations that occur in parallel with the degree and duration of iodine deprivation. Iodine prophylaxis should be given systematically to women during pregnancy. In most public health programmes dealing with the correction of iodine deficiency disorders, iodised salt has been used as the preferred means to deliver iodine to households. Iodised salt, however, is not the ideal means of delivering iodine in the specific instances of pregnancy, breast-feeding and complementary feeding because of the need to limit salt intake during these periods. In European countries, presently it is proposed that iodine is given to pregnant women and breast-feeding mothers by systematically administering multivitamin tablets containing iodine in order to reach the recommended dietary allowance of 250 microg iodine day-1.

Biofortification of lettuce (Lactuca sativa L.) with iodine: The effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture

NARCIS (Netherlands)

Voogt, W.; Holwerda, H.T.; Khodabaks, M.R.

2010-01-01

BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration

Iodine uptake and prostate cancer in the TRAMP mouse model.

Science.gov (United States)

Olvera-Caltzontzin, Paloma; Delgado, Guadalupe; Aceves, Carmen; Anguiano, Brenda

2013-11-08

Iodine supplementation exerts antitumor effects in several types of cancer. Iodide (I⁻) and iodine (I₂) reduce cell proliferation and induce apoptosis in human prostate cancer cells (LNCaP and DU-145). Both chemical species decrease tumor growth in athymic mice xenografted with DU-145 cells. The aim of this study was to analyze the uptake and effects of iodine in a preclinical model of prostate cancer (transgenic adenocarcinoma of the mouse prostate [TRAMP] mice/SV40-TAG antigens), which develops cancer by 12 wks of age. ¹²⁵I⁻ and ¹²⁵I₂ uptake was analyzed in prostates from wild-type and TRAMP mice of 12 and 24 wks in the presence of perchlorate (inhibitor of the Na⁺/I⁻ symporter [NIS]). NIS expression was quantified by quantitative polymerase chain reaction (qPCR). Mice (6 wks old) were supplemented with 0.125 mg I⁻ plus 0.062 mg I₂/mouse/day for 12 or 24 wks. The weight of the genitourinary tract (GUT), the number of acini with lesions, cell proliferation (levels of proliferating cell nuclear antigen [PCNA] by immunohistochemistry), p53 and p21 expression (by qPCR) and apoptosis (relative amount of nucleosomes by enzyme-linked immunosorbent assay) were evaluated. In both age-groups, normal and tumoral prostates take up both forms of iodine, but only I⁻ uptake was blocked by perchlorate. Iodine supplementation prevented the overexpression of NIS in the TRAMP mice, but had no effect on the GUT weight, cell phenotype, proliferation or apoptosis. In TRAMP mice, iodine increased p53 expression but had no effect on p21 (a p53-dependent gene). Our data corroborate NIS involvement in I⁻ uptake and support the notion that another transporter mediates I₂ uptake. Iodine did not prevent cancer progression. This result could be explained by a strong inactivation of the p53 pathway by TAG antigens.

Determination of ultra-low level ¹²⁹I in vegetation using pyrolysis for iodine separation and accelerator mass spectrometry measurements

DEFF Research Database (Denmark)

Hou, Xiaolin; Wang, Yanyun

2016-01-01

Radioactive isotopes of iodine are the most common radiological toxins from nuclear accidents due to their high release and high enrichment in human thyroid. Among the radioactive isotopes, long-lived 129I can not only be used for the estimation of the radioactive risk of short-lived radioactive...... and ultra-low concentration in normal environmental and biological samples, it is important to efficiently separate iodine from the sample matrix and sensitively measure 129I. However, the complicated chemical properties of iodine and high organic content in biological samples make efficient separation...... of iodine very difficult using conventional acid digestion and alkaline ashing methods. By optimizing the key parameters related to the separation of iodine by pyrolysis using a tube furnace, including carbonization temperature, heating protocol, combustion assisting gas, iodine volatilization process...

Heterogeneous equilibrium in mplybdenum-iodine system

International Nuclear Information System (INIS)

Klinkova, L.A.

1983-01-01

Heterogeneous equilibrium in the Mo-J system is studied to reveal regions of existence of molybdenum iodides, is studied. The investigation is performed for atomic ratio I/Mo=0.02-7.5 in the temperature range of 300-1370 K using methods of thermographic, X-ray phase, chemical and optical analyses of phases quenched after isothermal annealing. It is shown that higher molybdenum iodides (Mo1 4 , MoJ 5 , MoJ 6 ) are thermally unstable compounds and exist in the Mo-J system at low temperatures (360-490 K). Above 470 K higher iodides dissociate up to molybdenum triiodide. MoJ 3 under the pressure of iodine vapors is stable up to 970 K. Molybdenum diiodide is the product of triiodide decomposition and forms in the Mo-J system in the 700-1270 K range. At the J/Mo>>3 ratio the product of triiodide decomposition is MoJsub(2.87) which is thermally unstable up to 570 K, while in iodine atmosphere - up to 1170 K

Relationship between iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid washout ratio and oxygen consumption in normal and ischemic myocardium

International Nuclear Information System (INIS)

Saito, Kimimasa; Okamoto, Ryuji; Saito, Yasuhiro

1997-01-01

The relationship between oxygen consumption and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid ( 123 I-BMIPP) washout at rest and after exercise was investigated in normal and ischemic myocardium. Sixteen healthy volunteers and 14 patients with ischemic heart disease were examined. After injection of 111 MBq of 123 I-BMIPP, serial single photon emission computed tomography imaging was performed to evaluate washout ratio after 30 min and 1 hour of rest and after exercise. In the volunteers, the mean washout ratio was 3.3±3.5% after 1 hour of rest and increased during exercise. The exercise washout ratio showed a better correlation with net pressure rate product (net PRP: cumulative values of PRP during exercise) than with the peak PRP. The exercise washout ratio showed a strong correlation with the net PRP in the range from 180 to 300x10 3 mmHg·beat/min and a plateau of 10-15%. In the nine ischemic patients with net PRP≥300x10 3 mmHg·beat/min, the exercise washout ratio values were significantly elevated in normal segments relative to ischemic segments (10.1±1.9% vs 4.7±2.9%, p 3 mmHg·beat/min, washout ratio at rest and after exercise did not differ significantly between normal and ischemic segments. 123 I-BMIPP washout ratio increased with increased oxygen consumption during exercise in normal myocardium but not in ischemic myocardium. The patient must exercise before fatty acid metabolism can be compared between normal and ischemic myocardium. (author)

Experimental reproduction of iodine deficiency in cattle.

Science.gov (United States)

McCoy, M A; Smyth, J A; Ellis, W A; Arthur, J R; Kennedy, D G

1997-11-22

The role of iodine deficiency in stillbirth/perinatal weak calf syndrome was investigated in pregnant heifers. Five heifers were fed an iodine deficient diet (mean [sd] iodine concentration 0.06 [0.01] mg/kg dry matter [DM]) and six received an iodine sufficient diet (mean [sd] iodine concentration 1.45 [0.27] mg/kg DM). The diets consisted of wheat and soyabean meal with added minerals and vitamins (with or without iodine) and were fed to the heifers over the final four to five months of pregnancy. The iodine deficient diet produced clinicopathological changes and pathological changes in the thyroid glands of both the heifers and their offspring. However, all the calves in the iodine deficient group were born clinically normal.

Silver iodide reduction in aqueous solution: application to iodine enhanced separation during spent nuclear fuels reprocessing

International Nuclear Information System (INIS)

Badie, Jerome

2002-01-01

Silver iodide is a key-compound in nuclear chemistry either in accidental conditions or during the reprocessing of spent nuclear fuel. In that case, the major part of iodine is released in molecular form into the gaseous phase at the time of dissolution in nitric acid. In French reprocessing plants, iodine is trapped in the dissolver off-gas treatment unit by two successive steps: the first consists in absorption by scrubbing with a caustic soda solution and in the second, residual iodine is removed from the gaseous stream before the stack by chemisorption on mineral porous traps made up of beds of amorphous silica or alumina porous balls impregnated with silver nitrate. Reactions of iodine species with the impregnant are assumed to lead to silver iodide and silver iodate. Enhanced separation policy would make necessary to recover iodine from the filters by silver iodide dissolution during a reducing treatment. After a brief silver-iodine chemical bibliographic review, the possible reagents listed in the literature were studied. The choice has been made to use ascorbic acid and hydroxylamine. An experimental work on silver iodide reduction by this two compounds allowed us to determinate reaction products, stoichiometry and kinetics parameters. Finally, the process has been initiated on stable iodine loaded filters samples. (author) [fr

The evaluation of secondary system oxygen-scavenging chemicals using a water-circulating rig

Energy Technology Data Exchange (ETDEWEB)

Collins, M.W. [Nuclear Dept., HMS Sultan (United Kingdom)

2002-07-01

To assess the efficiency, mode of action and possible by-products of chemical dosing agents, e.g. oxygen scavengers, a circulating water rig was constructed. The rig uses a demineralized water supply as a source of make-up water to fill a recirculating loop of approx. 10 litres volume. The rig pipework is made of polythene with standard off-the shelf pipe fittings and connectors. The following parameters can be measured within the rig: pH and conductivity measured by in-line monitor, dissolved oxygen level, temperature. The system has already been used for some preliminary testing. The following oxygen scavengers have been used for tests: ascorbic acid (vitamin C), N,N-diethyl-hydroxylamine (DEHA), Hydroquinone, hydrazine hydrate and anhydrous sodium sulfite. (authors)

The evaluation of secondary system oxygen-scavenging chemicals using a water-circulating rig

International Nuclear Information System (INIS)

Collins, M.W.

2002-01-01

To assess the efficiency, mode of action and possible by-products of chemical dosing agents, e.g. oxygen scavengers, a circulating water rig was constructed. The rig uses a demineralized water supply as a source of make-up water to fill a recirculating loop of approx. 10 litres volume. The rig pipework is made of polythene with standard off-the shelf pipe fittings and connectors. The following parameters can be measured within the rig: pH and conductivity measured by in-line monitor, dissolved oxygen level, temperature. The system has already been used for some preliminary testing. The following oxygen scavengers have been used for tests: ascorbic acid (vitamin C), N,N-diethyl-hydroxylamine (DEHA), Hydroquinone, hydrazine hydrate and anhydrous sodium sulfite. (authors)

Iodine removing method in organic solvent

International Nuclear Information System (INIS)

Suzuki, Takeo; Sakurai, Manabu

1988-01-01

Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

Effect of vapor-phase oxygen on chemical vapor deposition growth of graphene

Science.gov (United States)

Terasawa, Tomo-o.; Saiki, Koichiro

2015-03-01

To obtain a large-area single-crystal graphene, chemical vapor deposition (CVD) growth on Cu is considered the most promising. Recently, the surface oxygen on Cu has been found to suppress the nucleation of graphene. However, the effect of oxygen in the vapor phase was not elucidated sufficiently. Here, we investigate the effect of O2 partial pressure (PO2) on the CVD growth of graphene using radiation-mode optical microscopy. The nucleation density of graphene decreases monotonically with PO2, while its growth rate reaches a maximum at a certain pressure. Our results indicate that PO2 is an important parameter to optimize in the CVD growth of graphene.

Clinical and Biochemical Uses of Stable Iodine Measurements

Energy Technology Data Exchange (ETDEWEB)

Koutras, D. A. [Thyroid Section, Alexandra Hospital, Athens (Greece)

1970-07-01

Iodine and thyroid function are closely linked, since the only known role of iodine is its participation in the synthesis of thyroid hormones. Iodine metabolism may be represented as a metabolic cycle consisting of three main pools: the Plasma Inorganic Iodine (PIl) pool into which dietary iodine goes and from where it is either taken up by the thyroid or excreted by the kidneys, the intrathyroidal iodine pool, where. thyroid hormone synthesis occurs, and finally the peripheral pool of thyroid hormones, of which about 80% are deiodinated and 20% excreted with the faeces. Endemic goitre is usually due to iodine deficiency. There is no renal homeostatic mechanism to keep the PII level constant, and so adaptation to iodine deficiency occurs by increasing the thyroidal iodide clearance rate. Stable iodine measurements are necessary for a complete study of iodine metabolism. Estimates of the serum Protein-Bound Iodine (PBl) are the best index of thyroid function, estimates of the PII and of the urinary iodine are the best indices of iodine nutrition. (author)

Iodine doping effects on the lattice thermal conductivity of oxidized polyacetylene nanofibers

Energy Technology Data Exchange (ETDEWEB)

Bi, Kedong, E-mail: lishi@mail.utexas.edu, E-mail: kedongbi@seu.edu.cn [Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China); Department of Mechanical Engineering, University of Texas at Austin, Austin, Texas 78712 (United States); Weathers, Annie; Pettes, Michael T.; Shi, Li, E-mail: lishi@mail.utexas.edu, E-mail: kedongbi@seu.edu.cn [Department of Mechanical Engineering, University of Texas at Austin, Austin, Texas 78712 (United States); Matsushita, Satoshi; Akagi, Kazuo [Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510 (Japan); Goh, Munju [Department of Polymer Chemistry, Kyoto University, Kyoto 615-8510 (Japan); Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Eunha-ri san 101, Bondong-eup, Wanju-gun, Jeolabuk-do 565-905 (Korea, Republic of)

2013-11-21

Thermal transport in oxidized polyacetylene (PA) nanofibers with diameters in the range between 74 and 126 nm is measured with the use of a suspended micro heater device. With the error due to both radiation and contact thermal resistance corrected via a differential measurement procedure, the obtained thermal conductivity of oxidized PA nanofibers varies in the range between 0.84 and 1.24 W m{sup −1} K{sup −1} near room temperature, and decreases by 40%–70% after iodine doping. It is also found that the thermal conductivity of oxidized PA nanofibers increases with temperature between 100 and 350 K. Because of exposure to oxygen during sample preparation, the PA nanofibers are oxidized to be electrically insulating before and after iodine doping. The measurement results reveal that iodine doping can result in enhanced lattice disorder and reduced lattice thermal conductivity of PA nanofibers. If the oxidation issue can be addressed via further research to increase the electrical conductivity via doping, the observed suppressed lattice thermal conductivity in doped polymer nanofibers can be useful for the development of such conducting polymer nanostructures for thermoelectric energy conversion.

Iodine doping effects on the lattice thermal conductivity of oxidized polyacetylene nanofibers

International Nuclear Information System (INIS)

Bi, Kedong; Weathers, Annie; Pettes, Michael T.; Shi, Li; Matsushita, Satoshi; Akagi, Kazuo; Goh, Munju

2013-01-01

Thermal transport in oxidized polyacetylene (PA) nanofibers with diameters in the range between 74 and 126 nm is measured with the use of a suspended micro heater device. With the error due to both radiation and contact thermal resistance corrected via a differential measurement procedure, the obtained thermal conductivity of oxidized PA nanofibers varies in the range between 0.84 and 1.24 W m −1  K −1 near room temperature, and decreases by 40%–70% after iodine doping. It is also found that the thermal conductivity of oxidized PA nanofibers increases with temperature between 100 and 350 K. Because of exposure to oxygen during sample preparation, the PA nanofibers are oxidized to be electrically insulating before and after iodine doping. The measurement results reveal that iodine doping can result in enhanced lattice disorder and reduced lattice thermal conductivity of PA nanofibers. If the oxidation issue can be addressed via further research to increase the electrical conductivity via doping, the observed suppressed lattice thermal conductivity in doped polymer nanofibers can be useful for the development of such conducting polymer nanostructures for thermoelectric energy conversion

Iodine nutrition status in lactating mothers residing in countries with mandatory and voluntary iodine fortification programs: an updated systematic review.

Science.gov (United States)

Nazeri, Pantea; Mirmiran, Parvin; Shiva, Niloofar; Mehrabi, Yadollah; Mojarrad, Mehdi; Azizi, Fereidoun

2015-06-01

The aim of this review is to assess data available on iodine nutrition status in lactating mothers residing in countries with mandatory and voluntary iodine fortification programs and/or iodine supplementation. A systematic review was conducted by searching articles published between 1964 and 2013 in Pub Med, ISI Web, and Cochrane Library using iodine nutrition, lactation, iodine supplementation, and iodine fortification as keywords for titles and/or abstracts. Relevant articles were included if they reported urinary iodine concentration (UIC) in lactating mothers and, if determined, the type of iodine fortification program and/or iodine supplementation. Forty-two studies met the inclusion criteria. Among these, 21 studies assessed lactating mothers in countries with a mandatory iodine fortification program, 17 studies were from countries with voluntary and/or without iodine fortification programs, and four studies assessed iodine nutrition status in lactating mothers undergoing iodine supplementation. Among countries with mandatory iodine fortification programs, the range of salt iodization level in lactating mothers with a UIC 100 μg/L, it was between 15 and 60 ppm. Levels of UIC Chile, Iran, Mongolia, New Guinea, and Nigeria, the median or mean of UIC was >100 μg/L. There was a median or mean UIC program was voluntary, including Switzerland, Australia, New Zealand, Ireland, and Germany. However, in some countries with voluntary iodine fortification programs, such as the United States, Spain, and Japan, a mean or median UIC of >100 μg/L has been reported. Although universal salt iodization is still the most feasible and cost-effective approach for iodine deficiency control in pregnant and lactating mothers, UIC in lactating mothers of most countries with voluntary programs and in areas with mandatory iodine fortification is still within the iodine deficiency range, indicating that iodine supplementation in daily prenatal vitamin/mineral supplements in

Mock iodine-125 radiation source

International Nuclear Information System (INIS)

Coffey, D.L.

1976-01-01

An intimate mixture of americium-241 and iodine-129 provides an energy spectrum that reliably simulates the spectrum of iodine-125 in a well-type detector. As such, it may be used as a long-lived standard to calibrate instruments such as well scintillation spectrometers in which measurements are to be made involving iodine-125

Iodine deficiency disorders in Sarawak, Malaysia.

Science.gov (United States)

Kiyu, A; Tambi, Z; Ahmad, Y

1998-12-01

The state of Sarawak in Malaysia has a high prevalence of iodine deficiency disorders (IDD). This has been revealed through a review of goitre surveys that were carried out in the State from the early 1970s to the 1990s. The primary cause was low iodine intake. Contributory factors were low iodine content in the soil and water as well as high cassava consumption. Virtual elimination of IDD is one of the nutritional goals of the IDD prevention and control programs. The strategies adopted include the iodination of coarse salt, which is sold in the market by shopkeepers and also provided free from government health clinics; legislation requiring that salt sold in IDD-gazetted areas must be iodised; and the use of iodinators to iodise water supplied by the gravity-feed system to villages and boarding schools in rural areas. The indicators used in the monitoring and evaluation of the program include the availability of iodised salt in the market and households, iodine levels in water supply that had been fitted with iodinators, goitre volume measured by ultrasound, and urinary iodine excretion among school children.

Iodine in soil

International Nuclear Information System (INIS)

Johanson, Karl Johan

2000-12-01

A literature study of the migration and the appearance of iodine isotopes in the bio-sphere particularly in soil is presented. Some important papers in the field of iodine appearance in soil and the appearance of 129 I in the surroundings of reprocessing plants are discussed. The most important conclusions are: 1. Iodine binds to organic matter in the soil and also to some oxides of aluminium and iron. 2. If the iodine is not bound to the soil a large fraction of added 129 I is volatilized after a rather short period. 3. The binding and also the volatilisation seems to be due to biological activity in the soil. It may take place within living microorganisms or by external enzymes excreted from microorganisms. 4. Due to variations in the composition of soil there may be a large variation in the distribution of 129 I in the vertical profile of soil - usually most of the 129 I in the upper layer - which also results in large variations in the 129 I uptake to plants

Iodine in soil

Energy Technology Data Exchange (ETDEWEB)

Johanson, Karl Johan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

2000-12-01

A literature study of the migration and the appearance of iodine isotopes in the bio-sphere particularly in soil is presented. Some important papers in the field of iodine appearance in soil and the appearance of {sup 129}I in the surroundings of reprocessing plants are discussed. The most important conclusions are: 1. Iodine binds to organic matter in the soil and also to some oxides of aluminium and iron. 2. If the iodine is not bound to the soil a large fraction of added {sup 129}I is volatilized after a rather short period. 3. The binding and also the volatilisation seems to be due to biological activity in the soil. It may take place within living microorganisms or by external enzymes excreted from microorganisms. 4. Due to variations in the composition of soil there may be a large variation in the distribution of {sup 129}I in the vertical profile of soil - usually most of the {sup 129}I in the upper layer - which also results in large variations in the {sup 129}I uptake to plants.

Intravascular enhancement with identical iodine delivery rate using different iodine contrast media in a circulation phantom.

Science.gov (United States)

Mihl, Casper; Wildberger, Joachim E; Jurencak, Tomas; Yanniello, Michael J; Nijssen, Estelle C; Kalafut, John F; Nalbantov, Georgi; Mühlenbruch, Georg; Behrendt, Florian F; Das, Marco

2013-11-01

Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR. A circulation phantom with a low-pressure venous compartment and a high-pressure arterial compartment simulating physiological circulation parameters was used (heart rate, 60 beats per minute; stroke volume, 60 mL; blood pressure, 120/80 mm Hg). Maintaining a constant IDR (2.0 g/s) and a constant total iodine load (20 g), prewarmed (37°C) contrast media with differing iodine concentrations (240-400 mg/mL) were injected into the phantom using a double-headed power injector. Serial computed tomographic scans at the level of the ascending aorta (AA), the descending aorta (DA), and the left main coronary artery (LM) were obtained. Total amount of contrast volume (milliliters), iodine delivery (grams of iodine), peak flow rate (milliliter per second), and intravascular pressure (pounds per square inch) were monitored using a dedicated data acquisition program. Attenuation values in the AA, the DA, and the LM were constantly measured (Hounsfield unit [HU]). In addition, time-enhancement curves, aortic peak enhancement, and time to peak were determined. All contrast injection protocols resulted in similar attenuation values: the AA (516 [11] to 531 [37] HU), the DA (514 [17] to 531 [32] HU), and the LM (490 [10] to 507 [17] HU). No significant differences were found between the AA, the DA, and the LM for either peak enhancement (all P > 0.05) or mean time to peak (AA, 19.4 [0.58] to 20.1 [1.05] seconds; DA, 21.1 [1.0] to 21.4 [1.15] seconds; LM, 19.8 [0.58] to 20.1 [1.05] seconds). This phantom study demonstrates that

Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

Energy Technology Data Exchange (ETDEWEB)

Peleias Junior, Fernando S.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M., E-mail: fernandopeleias@gmail.com, E-mail: czeituni@ipen.br, E-mail: elisaros@ipen.br; and others

2013-07-01

Cancer is a term used generically to represent a group of more than 100 illnesses, including malignant tumors from different locations. According to World Health Organization (WHO), is a leading cause of death worldwide, accounted for 7.6 million deaths. Prostate cancer is the sixth most common type in the world, representing about 10% of all cases of cancer and its treatment may be by surgery, radiotherapy or even vigilant observation. A method of radiotherapy which has been extensively used in the early and intermediate stages of the illness is brachytherapy, where radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope Iodine-125, adsorbed on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive Iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. The methodology used was chosen based on the available infrastructure and experience of the researchers of the institute. Therefore, Iodine-131 was used for testing (same chemical behavior of Iodine -125). Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16% ; method 2 (chemical reaction based on the method developed by David Kubiatowicz -HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80% . Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN. (author)

Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources

International Nuclear Information System (INIS)

Peleias Junior, Fernando S.; Zeituni, Carlos A.; Rostelato, Maria Elisa C.M.

2013-01-01

Cancer is a term used generically to represent a group of more than 100 illnesses, including malignant tumors from different locations. According to World Health Organization (WHO), is a leading cause of death worldwide, accounted for 7.6 million deaths. Prostate cancer is the sixth most common type in the world, representing about 10% of all cases of cancer and its treatment may be by surgery, radiotherapy or even vigilant observation. A method of radiotherapy which has been extensively used in the early and intermediate stages of the illness is brachytherapy, where radioactive seeds are placed inside or next to the area requiring treatment, which reduces the probability of unnecessary damage to surrounding healthy tissues. Currently, the radioactive isotope Iodine-125, adsorbed on silver substrate, is one of the most used in prostate brachytherapy. The present study compares several deposition methods of radioactive Iodine on silver substrate, in order to choose the most suitable one to be implemented at the laboratory of radioactive sources production of IPEN. The methodology used was chosen based on the available infrastructure and experience of the researchers of the institute. Therefore, Iodine-131 was used for testing (same chemical behavior of Iodine -125). Three methods were selected: method 1 (test based on electrodeposition method, developed by David Kubiatowicz) which presented efficiency of 65.16% ; method 2 (chemical reaction based on the method developed by David Kubiatowicz -HCl) which presented efficiency of 70.80%; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) which presented efficiency of 55.80% . Based on the results, the second method is the suggested one to be implemented at the laboratory of radioactive sources production of IPEN. (author)

Study of Iodine Prophylaxis Following Nuclear Accidents

International Nuclear Information System (INIS)

Sri Widayati; Tedjasari, R. S.; Elfida

2007-01-01

Study of iodine prophylaxis following nuclear accidents has been done. Giving stable iodine to a population exposed by I-131 is one of preventive action from internal radiation to the thyroid gland. Stable iodine could be given as Kl tablet in a range of dose of 30 mg/day to 130 mg/day. Improper giving of stable iodine could cause side effect to health, so then some factors should be considered i. e. dose estimation, age, dose of stable iodine to be given, duration of stable iodine prophylaxis and risk of health. (author)

New insights into the chemical behaviour of radioiodine in aquatic environments

International Nuclear Information System (INIS)

Behrens, H.

1982-04-01

It was found that in surface fresh water and in soil water iodine is to a large extent chemically converted by processes which are instigated by microbial action. The reactions involve extracellular oxidation of iodide with subsequent incorporation of the iodine into organic compounds, probably proteins. Furthermore it was found that iodate is reduced, probably also by a biochemical reaction. This reduction is more pronounced in soil than in surface water. In surface fresh water the formed organic radioiodine compounds are mainly in solution. In soils the radioiodine becomes to a larger extent bound to insoluble organic substances by these processes. The dissolved form of organic iodine is not precipitable as silver halide. Some other chemical and physico-chemical properties are described. Details on how the iodine conversion influences its fixation processes in soil are given. Possible consequences of these reactions on the migration behaviour of radioiodine and on the performance as well as on the interpretation of experiments in this context are discussed. (orig.)

Iodine deficiency in pregnancy and the effects of maternal iodine supplementation on the offspring: a review

NARCIS (Netherlands)

Zimmermann, M.B.

2009-01-01

The World Health Organization (WHO) recently increased their recommended iodine intake during pregnancy from 200 to 250 µg/d and suggested that a median urinary iodine (UI) concentration of 150-249 µg/L indicates adequate iodine intake in pregnant women. Thyrotropin concentrations in blood collected

PARIS project: Radiolytic oxidation of molecular iodine in containment during a nuclear reactor severe accident

Energy Technology Data Exchange (ETDEWEB)

Bosland, L. [Institut de Radioprotection et de Surete Nucleaire, DPAM, SEMIC, LETR - CEN Cadarache, BP 3, 13115 Saint Paul Lez Durance (France)], E-mail: loic.bosland@irsn.fr; Funke, F. [AREVA NP GmbH, Technical Center, P.O. Box 1109, D-91001 Erlangen (Germany); Girault, N. [Institut de Radioprotection et de Surete Nucleaire, DPAM, SEMIC, LETR - CEN Cadarache, BP 3, 13115 Saint Paul Lez Durance (France); Langrock, G. [AREVA NP GmbH, Technical Center, P.O. Box 1109, D-91001 Erlangen (Germany)

2008-12-15

In case of a hypothetical severe accident in a nuclear LWR (light water reactor), the high radiation fields reached in the reactor containment building due to the release of fission products from the reactor core could induce air radiolysis. The air radiolysis products could, in turn, oxidise gaseous molecular iodine into aerosol-borne iodine-oxygen-nitrogen compounds. Thereby, this reaction involves a change of iodine speciation and a decrease of iodine volatility in the reactor containment atmosphere. Kinetic data were produced within the PARIS project on the air radiolysis products formation and destruction, and on their reaction with molecular iodine, with the objective of developing and validating existing kinetic models. The current paper includes the non-iodine tests of the PARIS project whose objective was to determine the rates of formation and destruction of air radiolysis products in the presence of both structural containment surfaces (decontamination coating ('paint') and stainless steel), aerosol particles such as silver rich particles (issued from the control rods) in boundary conditions representative for LWR or PHEBUS facility containments. It is found that the air radiolysis products concentration increases with dose and tend to approach saturation levels at doses higher than about 1 kGy. This behaviour is more evident in oxygen/steam atmospheres, producing ozone, than in air/30% (v/v) steam atmospheres, the latter favouring the model-predicted on-going production of nitrogen dioxide even at very high doses. No significant effect of temperature, dose rate and hydrogen addition (4%, v/v) was observed. Furthermore, the inserted surfaces do not exhibit significant effects on the air radiolysis concentrations. However, these 'non-noticeable influence' could be due to a masking of small effects by the appreciable scattering of the experimental air radiolysis product concentrations. The PARIS results are then analysed using two

PARIS project: Radiolytic oxidation of molecular iodine in containment during a nuclear reactor severe accident

International Nuclear Information System (INIS)

Bosland, L.; Funke, F.; Girault, N.; Langrock, G.

2008-01-01

In case of a hypothetical severe accident in a nuclear LWR (light water reactor), the high radiation fields reached in the reactor containment building due to the release of fission products from the reactor core could induce air radiolysis. The air radiolysis products could, in turn, oxidise gaseous molecular iodine into aerosol-borne iodine-oxygen-nitrogen compounds. Thereby, this reaction involves a change of iodine speciation and a decrease of iodine volatility in the reactor containment atmosphere. Kinetic data were produced within the PARIS project on the air radiolysis products formation and destruction, and on their reaction with molecular iodine, with the objective of developing and validating existing kinetic models. The current paper includes the non-iodine tests of the PARIS project whose objective was to determine the rates of formation and destruction of air radiolysis products in the presence of both structural containment surfaces (decontamination coating ('paint') and stainless steel), aerosol particles such as silver rich particles (issued from the control rods) in boundary conditions representative for LWR or PHEBUS facility containments. It is found that the air radiolysis products concentration increases with dose and tend to approach saturation levels at doses higher than about 1 kGy. This behaviour is more evident in oxygen/steam atmospheres, producing ozone, than in air/30% (v/v) steam atmospheres, the latter favouring the model-predicted on-going production of nitrogen dioxide even at very high doses. No significant effect of temperature, dose rate and hydrogen addition (4%, v/v) was observed. Furthermore, the inserted surfaces do not exhibit significant effects on the air radiolysis concentrations. However, these 'non-noticeable influence' could be due to a masking of small effects by the appreciable scattering of the experimental air radiolysis product concentrations. The PARIS results are then analysed using two different kinetic models

Iodine-125 and Iodine-131 in the Thames Valley and other areas

International Nuclear Information System (INIS)

Howe, J.R.; Lloyd, M.K.; Bowlt, C.

1985-01-01

Part of the Iodine-125 and Iodine-131 waste from hospitals and research centres is discarded down drains and passes through sewage and water reclamation works into the river system. Relatively high concentration of radioiodine occur in outfalls that discharge into the river Thames, lower levels are found in the mainstream river and less still in the reservoirs and tap water supplies abstracted from the river. The pathway from waste to drinking water could account for the low levels of Iodine-125 found in the thyroid glands of some farm animals and human beings in the Thames valley

Evaluation of soil-plant transfer factors of iodine. Estimation of annual ingestion for iodine from the diet

International Nuclear Information System (INIS)

Saas, Arsene.

1980-11-01

The author presents the iodine middle contents of the soils and vegetables. A synthesis on the iodine evolution in the soils and vegetables allows to conclude that the vegetable absorption of this isotope is correlated with the isotopiquely exchangeable iodine of the soil. The soil-plant transfer-factors are calculated for the vegetables, cereals, fruits from the stable iodine quantitative analysis. The annual iodine ingestion has been estimated from the dietary of the European Communites areas. This one is a little different of the quantity estimated by CRESTA-LACOURLY-R 2979, yet the contribution by consummation unity is different [fr

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level.

Science.gov (United States)

Sahoo, P; Ananthanarayanan, R; Malathi, N; Rajiniganth, M P; Murali, N; Swaminathan, P

2010-06-11

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels. Copyright 2010 Elsevier B.V. All rights reserved.

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level

International Nuclear Information System (INIS)

Sahoo, P.; Ananthanarayanan, R.; Malathi, N.; Rajiniganth, M.P.; Murali, N.; Swaminathan, P.

2010-01-01

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 μg L -1 levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L -1 levels, with modification in methodology for accurate detection of end point even at 10.0 μg L -1 levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 μg L -1 O 2 . Finally, several water samples containing dissolved oxygen from mg L -1 to μg L -1 levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 μg L -1 O 2 level is 0.14 (n = 5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 μg L -1 levels.

Real-Time Molecular Monitoring of Chemical Environment in ObligateAnaerobes during Oxygen Adaptive Response

Energy Technology Data Exchange (ETDEWEB)

Holman, Hoi-Ying N.; Wozei, Eleanor; Lin, Zhang; Comolli, Luis R.; Ball, David. A.; Borglin, Sharon; Fields, Matthew W.; Hazen, Terry C.; Downing, Kenneth H.

2009-02-25

Determining the transient chemical properties of the intracellular environment canelucidate the paths through which a biological system adapts to changes in its environment, for example, the mechanisms which enable some obligate anaerobic bacteria to survive a sudden exposure to oxygen. Here we used high-resolution Fourier Transform Infrared (FTIR) spectromicroscopy to continuously follow cellular chemistry within living obligate anaerobes by monitoring hydrogen bonding in their cellular water. We observed a sequence of wellorchestrated molecular events that correspond to changes in cellular processes in those cells that survive, but only accumulation of radicals in those that do not. We thereby can interpret the adaptive response in terms of transient intracellular chemistry and link it to oxygen stress and survival. This ability to monitor chemical changes at the molecular level can yield important insights into a wide range of adaptive responses.

Chemical treatment of wastewaters produced during separation of iodine 131; Traitement chimique des eaux residuaires provenant de la preparation d'iode-131

Energy Technology Data Exchange (ETDEWEB)

Cohen, P.; Marcaillou, J.; Amavis, R.

1959-06-22

The authors report the development and assessment of a chemical treatment of radioactive wastewaters by co-precipitation. This treatment is aimed at replacing a treatment based on the use of calcium phosphate which proved to be insufficient for wastewaters resulting from the production of iodine 131. After a presentation of the characteristics of the effluents to be processed, the authors report co-precipitation tests performed on effluents before release in the storage vessel (by using barium hydroxide, lead acetate or lead sulfate) and on effluents diluted on the storage vessel. They show that a co-precipitation method based on the use of lead sulfate in alkaline medium gives the best results.

Excess iodine promotes apoptosis of thyroid follicular epithelial cells by inducing autophagy suppression and is associated with Hashimoto thyroiditis disease.

Science.gov (United States)

Xu, Chengcheng; Wu, Fei; Mao, Chaoming; Wang, Xuefeng; Zheng, Tingting; Bu, Ling; Mou, Xiao; Zhou, Yuepeng; Yuan, Guoyue; Wang, Shengjun; Xiao, Yichuan

2016-12-01

The incidence of the autoimmune thyroid disease Hashimoto thyroiditis (HT) has increased in recent years, and increasing evidence supports the contribution of excess iodine intake to thyroid disease. In this study, we examined the status of autophagy and apoptosis in thyroid tissues obtained from patients with HT, and we determined the effects of excessive iodine on the autophagy and apoptosis of thyroid follicular cells (TFCs) in an attempt to elucidate the effects of excess iodine on HT development. Our results showed decreases in the autophagy-related protein LC3B-II, and increases in caspase-3 were observed in thyroid tissues from HT patients. Interestingly, the suppression of autophagy activity in TFCs was induced by excess iodine in vitro, and this process is mediated through transforming growth factor-β1 downregulation and activation of the Akt/mTOR signaling pathway. In addition, excess iodine induced autophagy suppression and enhanced reactive oxygen species (ROS) production and apoptosis of TFCs, which could be rescued by the activation of autophagy. Taken together, our results demonstrated that excess iodine contributed to autophagy suppression and apoptosis of TFCs, which could be important factors predisposing to increased risk of HT development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mineral resource of the month: iodine

Science.gov (United States)

Polyak, Désirée E.

2009-01-01

The article focuses on iodine, its benefits and adverse effects, and its production and consumption. It states that iodine is essential to humans for it produces thyroid hormones to nourish thyroid glands but excessive intake could cause goiter, hyperthyroidism or hypothyroidism. U.S. laws require salt iodization to help prevent diseases. Chile and Japan are the world's leading iodine producer while in the U.S. iodine is mined from deep well brines in northern Oklahoma.

Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation

Czech Academy of Sciences Publication Activity Database

Hou, XL.; Fogh, CL.; Kučera, Jan; Andersson, KG.; Dahlgaard, H.; Nielsen, SP.

2003-01-01

Roč. 308, 1, 2, 3 (2003), s. 97-109 ISSN 0048-9697 R&D Projects: GA AV ČR IPP1050128; GA AV ČR KSK4055109 Institutional research plan: CEZ:AV0Z1048901 Keywords : iodine * neutron activation analysis Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 1.455, year: 2003

Calcium and chemical looping technology for power generation and carbon dioxide (CO2) capture solid oxygen- and CO2-carriers

CERN Document Server

Fennell, Paul

2015-01-01

Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to chemical looping and combustion. Chapters review the market development, economics, and deployment of these systems, also providing detailed information on the variety of materials and processes that will help to shape the future of CO2 capture ready power plants. Reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to calcium and chemical loopingProvi

The Swiss lodized Salt Program Provides Adequate Iodine for School Children and Pregnant Women, but Weaning Infants Not Receiving Iodine-Containing Complementary Foods as well as Their Mothers Are Iodine Deficient

NARCIS (Netherlands)

Andersson, M.; Aeberli, I.; Wüst, N.; Piacenza, A.M.; Bucher, T.; Henschen, I.; Haldimann, M.; Zimmermann, M.B.

2010-01-01

Background: If children and pregnant women in the population are iodine sufficient, it is generally assumed infants are also sufficient. But weaning infants may be at risk of iodine deficiency because iodized salt contributes little dietary iodine during this period. To fill this gap, iodine

Iodine behaviour in severe accidents

Energy Technology Data Exchange (ETDEWEB)

Dutton, L M.C.; Grindon, E; Handy, B J; Sutherland, L [NNC Ltd., Knutsford (United Kingdom); Bruns, W G; Sims, H E [AEA Technology, Harwell (United Kingdom); Dickinson, S [AEA Technology, Winfrith (United Kingdom); Hueber, C; Jacquemain, D [IPSN/CEA, Cadarache, Saint Paul-Lez-Durance (France)

1996-12-01

A description is given of analyses which identify which aspects of the modelling and data are most important in evaluating the release of radioactive iodine to the environment following a potential severe accident at a PWR and which identify the major uncertainties which affect that release. Three iodine codes are used namely INSPECT, IODE and IMPAIR, and their predictions are compared with those of the PSA code MAAP. INSPECT is a mechanistic code which models iodine behaviour in the aqueous aerosol, spray water and sump water, and the partitioning of volatile species between the aqueous phases and containment gas space. Organic iodine is not modelled. IODE and IMPAIR are semi-empirical codes which do not model iodine behaviour in the aqueous aerosol, but model organic iodine. The fault sequences addressed are based on analyses for the Sizewell `B` design. Two types of sequence have been analysed.: (a) those in which a major release of fission products from the primary circuit to the containment occur, e.g. a large LOCAS, (b) those where the release by-passes the containment, e.g. a leak into the auxiliary building. In the analysis of the LOCA sequences where the pH of the sump is controlled to be a value of 8 or greater, all three codes predict that the oxidation of iodine to produce gas phase species does not make a significant contribution to the source term due to leakage from the reactor building and that the latter is dominated by iodide in the aerosol. In the case where the pH of the sump is not controlled, it is found that the proportion of gas phase iodine increases significantly, although the cumulative leakage predicted by all three codes is not significantly different from that predicted by MAAP. The radiolytic production of nitric acid could be a major factor in determining the pH, and if the pH were reduced, the codes predict an increase in gas phase iodine species leaked from the containment. (author) 4 figs., 7 tabs., 13 refs.

Iodine in Enteral and Parenteral Nutrition

NARCIS (Netherlands)

Zimmermann, M.B.; Crill, C.M.

2010-01-01

Iodine deficiency (ID) has multiple adverse effects on growth and development due to inadequate thyroid hormone production. Methods for assessment of iodine nutrition in individuals include the urinary iodine concentration (UI), thyroid size and thyroid function tests. The UI measured in several

Manual or automated measuring of antipsychotics' chemical oxygen demand.

Science.gov (United States)

Pereira, Sarah A P; Costa, Susana P F; Cunha, Edite; Passos, Marieta L C; Araújo, André R S T; Saraiva, M Lúcia M F S

2018-05-15

Antipsychotic (AP) drugs are becoming accumulated in terrestrial and aqueous resources due to their actual consumption. Thus, the search of methods for assessing the contamination load of these drugs is mandatory. The COD is a key parameter used for monitoring water quality upon the assessment of the effect of polluting agents on the oxygen level. Thus, the present work aims to assess the chemical oxygen demand (COD) levels of several typical and atypical antipsychotic drugs in order to obtain structure-activity relationships. It was implemented the titrimetric method with potassium dichromate as oxidant and a digestion step of 2h, followed by the measurement of remained unreduced dichromate by titration. After that, an automated sequential injection analysis (SIA) method was, also, used aiming to overcome some drawbacks of the titrimetric method. The results obtained showed a relationship between the chemical structures of antipsychotic drugs and their COD values, where the presence of aromatic rings and oxidable groups give higher COD values. It was obtained a good compliance between the results of the reference batch procedure and the SIA system, and the APs were clustered in two groups, with the values ratio between the methodologies, of 2 or 4, in the case of lower or higher COD values, respectively. The SIA methodology is capable of operating as a screening method, in any stage of a synthetic process, being also more environmentally friendly, and cost-effective. Besides, the studies presented open promising perspectives for the improvement of the effectiveness of pharmaceutical removal from the waste effluents, by assessing COD values. Copyright © 2018 Elsevier Inc. All rights reserved.

Iodine chemistry in a reactor regulation

Energy Technology Data Exchange (ETDEWEB)

Powers, D A [Nuclear Regulatory Commission, Washington, DC (United States). Advisory Committee on Reactor Safeguards

1996-12-01

Radioactive iodine has always been an important consideration in the regulation of nuclear power reactors to assure the health and safety of the public. Regulators adopted conservatively bounding predictions of iodine behavior in the earliest days of the development of nuclear power because there was so little known about either accidents or the chemistry of iodine. Today there is a flood of new information and understanding of the chemistry of iodine under reactor accident conditions. This paper offers some thoughts on how the community of scientists engaged in the study of iodine chemistry can present the results of their work so that it is more immediately adopted by the regulator. It is suggested that the scientific community consider the concept of consensus standards so effectively used within the engineering community to define the status of the study of radioactive iodine chemistry for reactor safety. (author) 9 refs.

Iodine chemistry in a reactor regulation

International Nuclear Information System (INIS)

Powers, D.A.

1996-01-01

Radioactive iodine has always been an important consideration in the regulation of nuclear power reactors to assure the health and safety of the public. Regulators adopted conservatively bounding predictions of iodine behavior in the earliest days of the development of nuclear power because there was so little known about either accidents or the chemistry of iodine. Today there is a flood of new information and understanding of the chemistry of iodine under reactor accident conditions. This paper offers some thoughts on how the community of scientists engaged in the study of iodine chemistry can present the results of their work so that it is more immediately adopted by the regulator. It is suggested that the scientific community consider the concept of consensus standards so effectively used within the engineering community to define the status of the study of radioactive iodine chemistry for reactor safety. (author) 9 refs

Iodine Prophylaxis and Nuclear Accidents

International Nuclear Information System (INIS)

Franic, Z.

1998-01-01

Iodine is a highly volatile element therefore being very mobile in the environment. It enters the metabolism of living organisms and is selectively taken up and concentrated in the thyroid gland. The plume (cloud-like formation) of radioactive material that might be released in the environment in the case of a serious nuclear accident, primarily consists of the radioactive isotopes of iodine. Among those, due to its decay properties, is the most important 131 I. The effective means of protecting the thyroid gland against exposure to radioactive iodine is an intake of stable iodine. Therefore, one of the central issues in the emergency planning is to determine whether and at which projected thyroid radiation dose stable iodine should be given to the population. The International Atomic Energy Agency (IAEA) set the generic optimized intervention value for iodine prophylaxis to 100 mGy of avertable committed dose to a thyroid.The prophylaxis is implemented by utilizing the pills of pills of potassium iodine (KI). The efficacy of KI in protecting the thyroid gland depends upon the time of intake relative to the start of exposure to radioactive iodine. The best results are obtained if KI is taken 1-2 hours before or immediately after the start of exposure. The recommended dosage, based upon the study performed by Il'in et.al. is 130 mg/day. KI should be taken at least three days after the acute exposure to radioiodine, to prevent accumulation in a thyroid gland of radioiodine excreted from the other compartments of the body. The largest epidemiological study on the effects of KI prophylaxis ever performed was the one in Poland after the Chernobyl accident. Stable iodine was given as single dose of KI solution to 10.5 million of children and 7 millions of adults. Among children no serious side effects were seen while only two adults (with previously recorded iodine sensitivity) had severe respiratory distresses. Polish experiences showed that rapid response to such

Physical and chemical characteristics of cashew nut flour stored and packaged with different packages

Directory of Open Access Journals (Sweden)

Bruna Carolina GADANI

Full Text Available Abstract The aim of this study was to evaluate the physical and chemical changes in cashew nut flour under different packaging and storage conditions. The flour samples were characterized according to their chemical composition, packaged in polystyrene trays associated with covering chloride polyvinyl (PVC, plastic pot of polyethylene terephthalate (PET, plastic packaging polyethylene (POL and without coating polystyrene trays (CON. All packages were stored for 225 days, evaluating every 45 days the moisture content of the flour as well as extracting their oil by the cold method for characterization on the following indexes: acidity, saponification, iodine, peroxide and refraction. There was slight and gradual increase in the moisture content from the 45th to the 225th day, especially for products packaged in PVC and without coating polystyrene trays (CON. The oil saponification indexes showed gradual decrease during storage, especially in flour without packaging (CON. There was a gradual increase in the iodine index until the 135th day, followed by decay. The acidity and peroxide indexes increased along with the storage time. However packages with lower oxygen and moisture permeability, such as PET and POL, minimized such changes, being therefore the most suitable for long-term storage.

Production of adsorbent from palm shell for radioactive iodine scrubbing process

International Nuclear Information System (INIS)

Mohamad Azman Che Mat Isa; Ku Halim Ku Hamid; Muhd Noor Muhd Yunus; Mohamad Puad Abu; Abdul Halim Badaruddin; Mohammad Nizammudin Abd Aziz; Muhd Ridwan Abdul Rahim

2010-01-01

The biggest biomass source in Malaysia comes from oil palm industry. According to the statistic of year 2004, Malaysia produced 40 million tones per year of biomass which 30 million tones of biomass originated from the oil palm industries. Therefore, the biomass waste such as palm kernel shell can be used to produce granular adsorbent for radioactive materials. For that reason, a newly system, called Rocking Kiln - Fluidized Bed (RK - FB) was developed to utilize large amount of the biomass to produce high value added product. Charcoal or chemically produced activated carbon could be produced by using the kiln. Washing process was introduced to remove particles, minerals and volatile matters from charcoal produced and then would create more surface area in the adsorbent by creating more active sites. In this research, the adsorbent produced was used to scrub iodine 131. In nuclear power reactor, iodine isotope 131 is produced during nuclear fission, and this elementary radioactive iodine may pollute exhaust air streams that could cause thyroid cancer. For removal of radioactive iodine, normally a potassium iodide - impregnated activated carbon (KI - AC) is used. Thus, a process will be developed to produce KI - AC and this product will be used to calculate the efficiency to remove the radioactive iodine 131.The results obtain show that adsorbent produced has a high potential to be used in radioactive adsorbing and likely more economics. This paper will elaborate further the experimental set-up of in Kiln - Fluidized Bed (RK - FB), adsorbent quality and radioactive scrubbing process. (author)

Transfer of gaseous iodine to Tradescantia

International Nuclear Information System (INIS)

Nakamura, Yuji; Ohmomo, Yoichiro.

1984-01-01

Transfer rates of gaseous elemental iodine and methyliodide from atmosphere to Tradescantia were investigated in relation to supposed genetic mutation due to radioactive iodine released from nuclear facilities. The estimated transfer rate of elemental iodine to the young buds of Tradescantia, which was given as the ratio of iodine uptake rate per unit weight of the plant to the concentration of the element in the air, was approximately 7 x 10 -2 cm 3 /g.sec, about 30 to 40 times higher than that of methyliodide. The contribution of direct deposition of elemental iodine was suggested to be significant, although methyliodide was mainly absorbed by respiration through stomata of the plant. (author)

Direct evidence for coastal iodine particles from Laminaria macroalgae – linkage to emissions of molecular iodine

Directory of Open Access Journals (Sweden)

G. McFiggans

2004-01-01

Full Text Available Renewal of ultrafine aerosols in the marine boundary layer may lead to repopulation of the marine distribution and ultimately determine the concentration of cloud condensation nuclei (CCN. Thus the formation of nanometre-scale particles can lead to enhanced scattering of incoming radiation and a net cooling of the atmosphere. The recent demonstration of the chamber formation of new particles from the photolytic production of condensable iodine-containing compounds from diiodomethane (CH2I2, (O'Dowd et al., 2002; Kolb, 2002; Jimenez et al., 2003a; Burkholder and Ravishankara, 2003, provides an additional mechanism to the gas-to-particle conversion of sulphuric acid formed in the photo-oxidation of dimethylsulphide for marine aerosol repopulation. CH2I2 is emitted from seaweeds (Carpenter et al., 1999, 2000 and has been suggested as an initiator of particle formation. We demonstrate here for the first time that ultrafine iodine-containing particles are produced by intertidal macroalgae exposed to ambient levels of ozone. The particle composition is very similar both to those formed in the chamber photo-oxidation of diiodomethane and in the oxidation of molecular iodine by ozone. The particles formed in all three systems are similarly aspherical. When small, those formed in the molecular iodine system swell only moderately when exposed to increased humidity environments, and swell progressively less with increasing size; this behaviour occurs whether they are formed in dry or humid environments, in contrast to those in the CH2I2 system. Direct coastal boundary layer observations of molecular iodine, ultrafine particle production and iodocarbons are reported. Using a newly measured molecular iodine photolysis rate, it is shown that, if atomic iodine is involved in the observed particle bursts, it is of the order of at least 1000 times more likely to result from molecular iodine photolysis than diiodomethane photolysis. A hypothesis for molecular

Adsorption modes of molecular iodine on defected boron nitrides: A DFT study

Science.gov (United States)

Arabieh, Masoud; Azar, Yavar Taghipour

2018-03-01

The interaction of molecular iodine with pristine and monovacant boron-nitride quantum dots (QDs) have been investigated using density functional theory. It was found that removing one B or N single atom significantly decreased the calculated Eg values at various exchange functional. In B-defected BN system, the localized spin densities canceled each other and overall polarization of system was found to be equal to unity. For N-defected system there was smaller spin densities localized on each closest B atoms. Both B- and N-vacancies caused appearance of new states in gap region. Our calculation revealed that spin density and polarization of defected system are localized on vacancy region and other atoms did not take part in this polarization. The results of electron localization function for N-DBN showed there was high density region at the position of removed nitrogen atom. The calculated adsorption energies implied that there was no significant chemical interaction between iodine molecule and pristine BN sheet. We suggested that when a deficiency was imposed to the BN sheet, the reactivity of the modified system toward iodine molecule significantly could increase. We found strong interaction between iodine and nitrogen atoms of B-DBN system. In the case of I2/N-DBN system the neighbor atoms had no contribution in spin polarization of the system and it seemed that all spin density of system transferred to the iodine molecule after adsorption. Strong correlation between molecular iodine orientation and BN-QDs via their interactions type has been clarified in this work. These findings may provide a deeper insight into halogen molecules interactions with low dimensional defected boron nitrides.

Immobilization of iodine in concrete

International Nuclear Information System (INIS)

Clark, W.E.; Thompson, C.T.

1977-01-01

A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3 to 20 wt percent iodine as Ba(IO 3 ) 2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO 3 ) 2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. 10 claims, 2 figures

MDCT angiography of the pulmonary arteries: intravascular contrast enhancement does not depend on iodine concentration when injecting equal amounts of iodine at standardized iodine delivery rates

International Nuclear Information System (INIS)

Keil, S.; Plumhans, C.; Behrendt, F.F.; Das, M.; Muehlenbruch, G.; Mahnken, A.H.; Guenther, R.W.; Stanzel, S.; Seidensticker, P.; Knackstedt, C.; Wildberger, J.E.

2008-01-01

To compare the impact of iodine concentration using two different contrast materials (CM) at standardized iodine delivery rate (IDR) and overall iodine load in 16-multidetector-row-CT-angiography (MDCTA) of the pulmonary arteries of 192 patients with known or suspected pulmonary embolism. One hundred three patients (group A) received 148 ml of a CM containing 300 mg iodine/ml (Ultravist 300 trademark, BayerScheringPharma) at a flow rate of 4.9 ml/s. Eighty-nine patients (group B) received 120 ml of a CM with a concentration of 370 mg iodine/ml (Ultravist370 trademark) at a flow rate of 4.0 ml/s, resulting in a standardized IDR (∝1.5 gI/s) and the same overall amount of iodine (44.4 g). Both CM injections were followed by a saline chaser. Mean density values were determined in the pulmonary trunk, the ascending and the descending aorta, respectively. Applying repeated-measures ANOVA, no statistically significant differences between both MDCTA protocols were found (p=0.5790): the mean density in the pulmonary trunk was 355±116 Hounsfield Units (group A) and 358±115 (group B). The corresponding values for the ascending and descending aorta were 295±79 (group A) and 284±65 (group B) as well as 272±71 and 262±70. In conclusion, the use of standardized IDR and overall iodine load provides comparable intravascular CM density in pulmonary 16-MDCTA for delivering contrast materials with different iodine concentrations. (orig.)

Iodine in drinking water varies by more than 100-fold in Denmark. Importance for iodine content of infant formulas

DEFF Research Database (Denmark)

Pedersen, K M; Laurberg, P; Nøhr, S

1999-01-01

The iodine intake level of the population is of major importance for the occurrence of thyroid disorders in an area. The aim of the present study was to evaluate the importance of drinking water iodine content for the known regional differences in iodine intake in Denmark and for the iodine content...

Immobilization of iodine in concrete

Science.gov (United States)

Clark, Walter E.; Thompson, Clarence T.

1977-04-12

A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3-20 wt. % iodine as Ba(IO.sub.3).sub.2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO.sub.3).sub.2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. BACKGROUND OF THE INVENTION This invention was made in the course of, or under a contract with the Energy Research and Development Administration. It relates in general to reactor waste solidification and more specifically to the immobilization of fission product radioactive iodine recovered from irradiated nuclear fuel for underground storage.