Fabrication, characterization and applications of iron selenide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hussain, Raja Azadar, E-mail: hussainazadar@yahoo.com; Badshah, Amin; Lal, Bhajan

This review article presents fabrication of FeSe by solid state reactions, solution chemistry routes, chemical vapor deposition, spray pyrolysis and chemical vapor transport. Different properties and applications such as crystal structure and phase transition, band structure, spectroscopy, superconductivity, photocatalytic activity, electrochemical sensing, and fuel cell activity of FeSe have been discussed. - Graphical abstract: Iron selenide can be synthesized by solid state reactions, chemical vapor deposition, solution chemistry routes, chemical vapor transport and spray pyrolysis. - Highlights: • Different fabrication methods of iron selenide (FeSe) have been reviewed. • Crystal structure, band structure and spectroscopy of FeSe have been discussed.more » • Superconducting, catalytic and fuel cell application of FeSe have been presented.« less

Radionuclide Basics: Technetium-99

EPA Pesticide Factsheets

Technetium-99 (chemical symbol Tc-99) is a silver-gray, radioactive metal. It occurs naturally in very small amounts in the earth's crust, but is primarily man-made. Technetium-99m is a short-lived form of Tc-99 that is used as a medical diagnostic tool.

Solid-gas phase equilibria and thermodynamic properties of cadmium selenide.

NASA Technical Reports Server (NTRS)

Sigai, A. G.; Wiedemeier, H.

1972-01-01

Accurate vapor pressures are determined through direct weight loss measurements using the Knudsen effusion technique. The experimental data are evaluated by establishing the mode of vaporization and determining the heat capacity of cadmium selenide at elevated temperatures. Additional information is obtained through a second- and third-law evaluation of data, namely, the heat of formation and the absolute entropy of cadmium selenide. A preferential loss of selenium during the initial heating of CdSe is observed, which leads to a deviation in stoichiometry.

Two-band induced superconductivity in single-layer graphene and topological insulator bismuth selenide

NASA Astrophysics Data System (ADS)

Talantsev, E. F.; Crump, W. P.; Tallon, J. L.

2018-01-01

Proximity-induced superconductivity in single-layer graphene (SLG) and in topological insulators represent almost ideal examples of superconductivity in two dimensions. Fundamental mechanisms governing superconductivity in the 2D limit are of central interest for modern condensed-matter physics. To deduce fundamental parameters of superconductor/graphene/superconductor and superconductor/bismuth selenide/superconductor junctions we investigate the self-field critical currents in these devices using the formalism of the Ambegaokar-Baratoff model. Our central finding is that the induced superconducting state in SLG and bismuth selenide each exhibits gapping on two superconducting bands. Based on recent results obtained on ultra-thin films of natural superconductors, including single-atomic layer of iron selenide, double and triple atomic layers of gallium, and several atomic layer tantalum disulphide, we conclude that a two-band induced superconducting state in SLG and bismuth selenide is part of a wider, more general multiple-band phenomenology of currently unknown origin.

Methylation and demethylation of intermediates selenide and methylselenol in the metabolism of selenium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohta, Yuki; Suzuki, Kazuo T.

2008-01-15

All nutritional selenium sources are transformed into the assumed common intermediate selenide for the syntheses of selenoproteins for utilization and/or of selenosugar for excretion. Methylselenol [monomethylselenide, MMSe] is the assumed intermediate leading to other methylated metabolites, dimethylselenide (DMSe) and trimethylselenonium (TMSe) for excretion, and also to the intermediate selenide from methylselenocysteine and methylseleninic acid (MSA). Here, related methylation and demethylation reactions were studied in vitro by providing chemically reactive starting substrates ({sup 76}Se-selenide, {sup 77}Se-MMSe and {sup 82}Se-DMSe) which were prepared in situ by the reduction of the corresponding labeled proximate precursors ({sup 76}Se-selenite, {sup 77}Se-MSA and {sup 82}Se-dimethylselenoxide (DMSeO),more » respectively) with glutathione, the three substrates being incubated simultaneously in rat organ supernatants and homogenates. The resulting chemically labile reaction products were detected simultaneously by speciation analysis with HPLC-ICP-MS after converting the products and un-reacted substrates to the corresponding oxidized derivatives (selenite, MSA and DMSeO). The time-related changes in selenium isotope profiles showed that demethylation of MMSe to selenide was efficient but that of DMSe to MMSe was negligible, whereas methylation of selenide to MMSe, and MMSe to DMSe were efficient, and that of DMSe to TMSe occurred less efficiently. The present methylation and demethylation reactions on equilibrium between selenide, MMSe and DMSe without producing selenosugar and selenoproteins indicated that DMSe rather than TMSe is produced as the end product, suggesting that DMSe is to be excreted more abundantly than TMSe. Organ-dependent differences in the methylation and demethylation reactions were characterized for the liver, kidney and lung.« less

Growth of zinc selenide crystals by physical vapor transport in microgravity

NASA Technical Reports Server (NTRS)

Rosenberger, Franz

1995-01-01

The growth of single crystals of zinc selenide was carried out by both closed ampoule physical vapor transport and effusive ampoule physical vapor transport (EAPVT). The latter technique was shown to be a much more efficient method for the seeded growth of zinc selenide, resulting in higher transport rates. Furthermore, EAPVT work on CdTe has shown that growth onto /n11/ seeds is advantageous for obtaining reduced twinning and defect densities in II-VI sphalerite materials.

A facile way to control phase of tin selenide flakes by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Wang, Zhigang; Pang, Fei

2018-06-01

Although two-dimensional (2D) tin selenides are attracting intense attentions, studies on its phase transition are still relatively few. Here we report a facile way to control the phase growth of tin selenide flakes on mica and SiO2/Si by only adjusting nominal Sn:Se ratio, which refers to the amount of loaded SnO2 and Se precursors. High normal Sn:Se ratio induced SnSe flakes, conversely SnSe2 flakes formed. It could be used as a practical guide to selectively synthesize pure phase of single crystalline 2D layered chalcogenide materials similar to tin selenides.

Bioinorganic Activity of Technetium Radiopharmaceuticals.

ERIC Educational Resources Information Center

Pinkerton, Thomas C.; And Others

1985-01-01

Technetium radiopharmaceuticals are diagnostic imaging agents used in the field of nuclear medicine to visualize tissues, anatomical structures, and metabolic disorders. Bioavailability of technetium complexes, thyroid imaging, brain imaging, kidney imaging, imaging liver function, bone imaging, and heart imaging are the major areas discussed. (JN)

Technetium recovery from high alkaline solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, Charles A.

2016-07-12

Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

Process for extracting technetium from alkaline solutions

DOEpatents

Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

1995-01-01

A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

Cuprous selenide and sulfide form improved photovoltaic barriers

NASA Technical Reports Server (NTRS)

1966-01-01

Photovoltaic barriers formed by depositing a layer of polycrystalline cuprous sulfide or cuprous selenide on gallium arsenide are chemically and electrically stable. The stability of these barrier materials is significantly greater than that of cuprous iodide.

Redox-dependent solubility of technetium in low activity waste glass

NASA Astrophysics Data System (ADS)

Soderquist, Chuck Z.; Schweiger, Michael J.; Kim, Dong-Sang; Lukens, Wayne W.; McCloy, John S.

2014-06-01

The solubility of technetium was measured in a Hanford low activity waste (LAW) glass simulant, to investigate the extent that technetium solubility controls the incorporation of technetium into LAW glass. A series of LAW glass samples, spiked with 500-6000 ppm of Tc as potassium pertechnetate, were melted at 1000 °C in sealed fused quartz ampoules. Technetium solubility was determined in the quenched bulk glass to be 2000-2800 ppm, with slightly reducing conditions due to choice of milling media resulting in reductant contamination and higher solubility. The chemical form of technetium obtained by X-ray absorption near edge spectroscopy is mainly isolated, octahedrally-coordinated Tc(IV), with a minority of Tc(VII) in some glasses and TcO2 in two glasses. The concentration and speciation of technetium depends on glass redox and amount of technetium added. Salts formed at the top of higher technetium loaded glasses during the melt. The results of this study show that technetium solubility should not be a factor in technetium retention during melting of Hanford LAW glass.

Kit for providing a technetium medical radioimaging agent

DOEpatents

Wildung, Raymond E.; Garland, Thomas R.; Li, Shu-Mei W.

2000-01-01

The present invention is directed toward a kit for microbial reduction of a technetium compound to form other compounds of value in medical imaging. The technetium compound is combined in a mixture with non-growing microbial cells which contain a technetium-reducing enzyme system, a stabilizing agent and an electron donor in a saline solution under anaerobic conditions. The mixture is substantially free of an inorganic technetium reducing agent and its reduction products. The resulting product is Tc of lower oxidation states, the form of which can be partially controlled by the stabilizing agent. It has been discovered that the microorganisms Shewanella alga, strain Bry and Shewanella putrifacians, strain CN-32 contain the necessary enzyme systems for technetium reduction and can form both mono nuclear and polynuclear reduced Tc species depending on the stabilizing agent.

Investigation of Cadmium Selenide Photoelectrochemical Cells.

DTIC Science & Technology

1980-01-01

80-4 _INVESTIGATION OF C ADMIUM ,ELENIDE .PHOTOELECTROCHEMICAL CELLS by R.A. Sawchuk and D.R. Snelling Energy Systems Section AccsseionPar Energy ...cadmium selenide photo- anodes, a polysulphide redox’electrolyte and an in situ energy storage com- partment were evaluated at DREO. The...electron-hole recombination.- centers, and shorting to the nickel substrate. The concept of in situ energy storage was not successfully demonstrated. It is

Phase-Engineered Type-II Multimetal-Selenide Heterostructures toward Low-Power Consumption, Flexible, Transparent, and Wide-Spectrum Photoresponse Photodetectors.

PubMed

Chen, Yu-Ze; Wang, Sheng-Wen; Su, Teng-Yu; Lee, Shao-Hsin; Chen, Chia-Wei; Yang, Chen-Hua; Wang, Kuangye; Kuo, Hao-Chung; Chueh, Yu-Lun

2018-05-01

Phase-engineered type-II metal-selenide heterostructures are demonstrated by directly selenizing indium-tin oxide to form multimetal selenides in a single step. The utilization of a plasma system to assist the selenization facilitates a low-temperature process, which results in large-area films with high uniformity. Compared to single-metal-selenide-based photodetectors, the multimetal-selenide photodetectors exhibit obviously improved performance, which can be attributed to the Schottky contact at the interface for tuning the carrier transport, as well as the type-II heterostructure that is beneficial for the separation of the electron-hole pairs. The multimetal-selenide photodetectors exhibit a response to light over a broad spectrum from UV to visible light with a high responsivity of 0.8 A W -1 and an on/off current ratio of up to 10 2 . Interestingly, all-transparent photodetectors are successfully produced in this work. Moreover, the possibility of fabricating devices on flexible substrates is also demonstrated with sustainable performance, high strain tolerance, and high durability during bending tests. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acute treatment with bis selenide, an organic compound containing the trace element selenium, prevents memory deficits induced by reserpine in rats.

PubMed

Bortolatto, Cristiani Folharini; Guerra Souza, Ana Cristina; Wilhelm, Ethel Antunes; Nogueira, Cristina Wayne

2013-01-01

Taking into account the promising pharmacological actions of (Z)-2,3-bis(4-chlorophenylselanyl) prop-2-en-1-ol) (bis selenide), an organic compound containing the trace element selenium, and the constant search for drugs that improve the cognitive performance, the objective of the present study was to investigate whether bis selenide treatment ameliorates memory deficits induced by reserpine in rats. For this aim, male adult rats received a single subcutaneous injection of reserpine (1 mg/kg), a biogenic amine-depleting agent used to induce memory deficit. After 24 h, bis selenide at doses of 25 and 50 mg/kg was administered to rats by intragastric route, and 1 h later, the animals were submitted to behavior tasks. The effects of acute administration of bis selenide on memory were evaluated by social recognition, step-down passive avoidance, and object recognition paradigms. Exploratory and locomotor activities of rats were determined using the open-field test. Analysis of data revealed that the social memory disruption caused by reserpine was reversed by bis selenide at both doses. In addition, bis selenide, at the highest dose, prevented the memory deficit resulting from reserpine administration to rats in step-down passive avoidance and object recognition tasks. No significant alterations in locomotor and exploratory behaviors were found in animals treated with reserpine and/or bis selenide. Results obtained from distinct memory behavioral paradigms revealed that an acute treatment with bis selenide attenuated memory deficits induced by reserpine in rats.

Morphology-Tuned Synthesis of Nickel Cobalt Selenides as Highly Efficient Pt-Free Counter Electrode Catalysts for Dye-Sensitized Solar Cells.

PubMed

Qian, Xing; Li, Hongmei; Shao, Li; Jiang, Xiancai; Hou, Linxi

2016-11-02

In this work, morphology-tuned ternary nickel cobalt selenides based on different Ni/Co molar ratios have been synthesized via a simple precursor conversion method and used as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). The experimental facts and mechanism analysis clarified the possible growth process of product. It can be found that the electrochemical performance and structures of ternary nickel cobalt selenides can be optimized by tuning the Ni/Co molar ratio. Benefiting from the unique morphology and tunable composition, among the as-prepared metal selenides, the electrochemical measurements showed that the ternary nickel cobalt selenides exhibited a more superior electrocatalytic activity in comparison with binary Ni and Co selenides. In particular, the three-dimensional dandelion-like Ni 0.33 Co 0.67 Se microspheres delivered much higher power conversion efficiency (9.01%) than that of Pt catalyst (8.30%) under AM 1.5G irradiation.

Technetium-99m: basic nuclear physics and chemical properties.

PubMed

Castronovo, F P

1975-05-01

The nuclear physics and chemical properties of technetium-99m are reviewed. The review of basic nuclear physics includes: classification of nuclides, nuclear stability, production of radionuclides, artificial production of molybdenum-99, production of technetium 99m and -99Mo-99mTc generators. The discussion of the chemistry of technetium includes a profile of several -99mCc-labeled radiopharmaceuticals.

Polarization Effects in the Luminescence of Cadmium Selenide Electrodes.

DTIC Science & Technology

1983-09-29

UWIS/DC/TR-83/3 Polarization Effects in the Luminescence of Cadmium Selenide Electrodes by Holger H. Streckert, Hal Van Ryswyk, Richard N. Biagioni ...Streckert, Hal Van Ryswyk, N00014-78-C-0633 Richard N. Biagioni and Arthur B. Ellis 9PEFRIGOGNZTNNAEADADDRESS 10. PROGRAM ELEMENT. PROJECT, TASKS

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide

DOE PAGES

Lee, Yeseul; Lo, Shih -Han; Chen, Changqiang; ...

2014-05-02

Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23–27μW cm –1 K –2 at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereasmore » comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. As a result, the corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.« less

Double-Diffusive Convection During Growth of Halides and Selenides

NASA Technical Reports Server (NTRS)

Singh, N. B.; Su, Ching-Hua; Duval, Walter M. B.

2015-01-01

Heavy metal halides and selenides have unique properties which make them excellent materials for chemical, biological and radiological sensors. Recently it has been shown that selenohalides are even better materials than halides or selenides for gamma-ray detection. These materials also meet the strong needs of a wide band imaging technology to cover ultra-violet (UV), midwave infrared wavelength (MWIR) to very long wavelength infrared (VLWIR) region for hyperspectral imager components such as etalon filters and acousto-optic tunable filters (AO). In fact AOTF based imagers based on these materials have some superiority than imagers based on liquid crystals, FTIR, Fabry-Perot, grating, etalon, electro-optic modulation, piezoelectric and several other concepts. For example, broadband spectral and imagers have problems of processing large amount of information during real-time observation. Acousto-Optic Tunable Filter (AOTF) imagers are being developed to fill the need of reducing processing time of data, low cost operation and key to achieving the goal of covering long-wave infrared (LWIR). At the present time spectral imaging systems are based on the use of diffraction gratings are typically used in a pushbroom or whiskbroom mode. They are mostly used in systems and acquire large amounts of hyperspectral data that is processed off-line later. In contrast, acousto-optic tunable filter spectral imagers require very little image processing, providing new strategies for object recognition and tracking. They are ideally suited for tactical situations requiring immediate real-time image processing. But the performance of these imagers depends on the quality and homogeneity of acousto-optic materials. In addition for many systems requirements are so demanding that crystals up to sizes of 10 cm length are desired. We have studied several selenides and halide crystals for laser and AO imagers for MWIR and LWIR wavelength regions. We have grown and fabricated crystals of

Cohesive Relations for Surface Atoms in the Iron-Technetium Binary System

DOE PAGES

Taylor, Christopher D.

2011-01-01

Iron-technetium alloys are of relevance to the development of waste forms for disposition of radioactive technetium-99 obtained from spent nuclear fuel. Corrosion of candidate waste forms is a function of the local cohesive energy () of surface atoms. A theoretical model for calculating is developed. Density functional theory was used to construct a modified embedded atom (MEAM) potential for iron-technetium. Materials properties determined for the iron-technetium system were in good agreement with the literature. To explore the relationship between local structure and corrosion, MEAM simulations were performed on representative iron-technetium alloys and intermetallics. Technetium-rich phases have lower , suggesting thatmore » these phases will be more noble than iron-rich ones. Quantitative estimates of based on numbers of nearest neighbors alone can lead to errors up to 0.5 eV. Consequently, atomistic corrosion simulations for alloy systems should utilize physics-based models that consider not only neighbor counts, but also local compositions and atomic arrangements.« less

Process for the extraction of technetium from uranium

DOEpatents

Gong, Cynthia-May S.; Poineau, Frederic; Czerwinski, Kenneth R.

2010-12-21

A spent fuel reprocessing method contacts an aqueous solution containing Technetium(V) and uranyl with an acidic solution comprising hydroxylamine hydrochloride or acetohydroxamic acid to reduce Tc(V) to Tc(II, and then extracts the uranyl with an organic phase, leaving technetium(II) in aqueous solution.

Bismuth selenides from St. Andreasberg, Germany: an oxidised five-element style of mineralisation and its relation to post-Variscan vein-type deposits of central Europe

NASA Astrophysics Data System (ADS)

Cabral, Alexandre Raphael; Ließmann, Wilfried; Jian, Wei; Lehmann, Bernd

2017-10-01

Carbonate veinlets at Roter Bär, a former underground mine in the polymetallic St. Andreasberg vein district of the Harz Mountains, Germany, host selenide minerals that are characterised as Bi-Ag-bearing clausthalite (PbSe), tiemannite (HgSe), guanajuatite (Bi2Se3) and a number of selenides of Bi, Zn, Cu, Ag and Pd. An unnamed Bi-Pb-Ag selenide species with some Hg and Cu, ideally Bi4Pb3Ag2Se10, is reported here. Specular hematite is disseminated within the clausthalite, at the marginal zones of which other selenide minerals are located. The occurrence of bohdanowiczite (AgBiSe2) and umangite (Cu3Se2) constrains the formation temperature to ≤120 °C, and the selenide-hematite assemblage (plus barite in the carbonate gangue) identifies highly oxidised conditions. Selenide assemblages of Pb, Bi, Ag, with and without Co and Ni, occur in many parts of the Variscan basement of central Europe (Harz, Erzgebirge, Schwarzwald and Bohemian Massif) and represent a high-oxidation variety of five-element (Ag-As-Bi-Co-Ni) veins.

Synthesis, structure, and thermal properties of soluble hydrazinium germanium(IV) and tin(IV) selenide salts.

PubMed

Mitzi, David B

2005-05-16

The crystal structures of two hydrazinium-based germanium(IV) and tin(IV) selenide salts are determined. (N(2)H(5))(4)Ge(2)Se(6) (1) [I4(1)cd, a = 12.708(1) Angstroms, c = 21.955(2) Angstroms, Z = 8] and (N(2)H(4))(3)(N(2)H(5))(4)Sn(2)Se(6) (2) [P, a = 6.6475(6) Angstroms, b = 9.5474(9) Angstroms, c = 9.8830(10) Angstroms, alpha = 94.110(2) degrees, beta = 99.429(2) degrees, gamma = 104.141(2) degrees, Z = 1] each consist of anionic dimers of edge-sharing metal selenide tetrahedra, M(2)Se(6)(4-) (M = Ge or Sn), separated by hydrazinium cations and, for 2, additional neutral hydrazine molecules. Substantial hydrogen bonding exists among the hydrazine/hydrazinium molecules as well as between the hydrazinium cations and the selenide anions. Whereas the previously reported tin(IV) sulfide system, (N(2)H(5))(4)Sn(2)S(6), decomposes cleanly to microcrystalline SnS(2) when heated to 200 degrees C in an inert atmosphere, higher temperatures (>300 degrees C) are required to dissociate selenium from 1 and 2 for the analogous preparations of single-phase metal selenides. The metal chalcogenide salts are highly soluble in hydrazine, as well as in a variety of amines and DMSO, highlighting the potential usefulness of these compounds as precursors for the solution deposition of the corresponding metal chalcogenide films.

A biokinetic model for systemic technetium in adult humans

DOE PAGES

Leggett, Richard Wayne; Giussani, Augusto

2015-04-10

The International Commission on Radiological Protection (ICRP) currently is updating its biokinetic and dosimetric models for internally deposited radionuclides. Technetium (Tc), the lightest element that exists only in radioactive form, has two important isotopes from the standpoint of potential risk to humans: the long-lived isotope 99Tm(T 1/2=2.1x10 5 y) is present in high concentration in nuclear waste, and the short-lived isotope 99mTc (T 1/2=6.02 h) is the most commonly used radionuclide in diagnostic nuclear medicine. This paper reviews data on the biological behavior of technetium and proposes a biokinetic model for systemic technetium in the adult human body formore » use in radiation protection. Compared with the ICRP s current occupational model for systemic technetium, the proposed model provides a more realistic description of the paths of movement of technetium in the body; provides greater consistency with experimental and medical data; and, for most radiosensitive organs, yields substantially different estimates of cumulative activity (total radioactive decays within the organ) following uptake of 99Tm or 99mTc to blood.« less

Recovery of Technetium Adsorbed on Charcoal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, Mark D.; Metz, Lori A.; Ballou, Nathan E.

2006-05-01

Two methods capable of near complete recovery of technetium adsorbed on charcoal are presented. The first involves liquid extraction of the technetium from the charcoal by hot 4M nitric acid. An average recovery of 98% (n=3) is obtained after three rounds of extraction. The second method involves dry ashing with air in a quartz combustion tube at 400-450 C. This method yields an average recovery of 96% (n=5). Other thermal methods were attempted, but resulted in reduced recovery and incomplete material balance

Process for removing technetium from iron and other metals

DOEpatents

Leitnaker, J.M.; Trowbridge, L.D.

1999-03-23

A process for removing technetium from iron and other metals comprises the steps of converting the molten, alloyed technetium to a sulfide dissolved in manganese sulfide, and removing the sulfide from the molten metal as a slag. 4 figs.

Co-electrospun lead selenide/titania-core/sheath nanowires for photovoltaic applications.

DOT National Transportation Integrated Search

2012-12-01

This study presents a novel, low-cost, all-inorganic lead selenide-titania (PbSe/TiO2) nanowire : heterostructure material synthesis for photovoltaic applications. PbSe nanorods (NRs) have been coelectrospun : within a TiO2 nanotube with high connect...

Basic electronic properties of iron selenide under variation of structural parameters

NASA Astrophysics Data System (ADS)

Guterding, Daniel; Jeschke, Harald O.; Valentí, Roser

2017-09-01

Since the discovery of high-temperature superconductivity in the thin-film FeSe /SrTiO3 system, iron selenide and its derivates have been intensively scrutinized. Using ab initio density functional theory calculations we review the electronic structures that could be realized in iron selenide if the structural parameters could be tuned at liberty. We calculate the momentum dependence of the susceptibility and investigate the symmetry of electron pairing within the random phase approximation. Both the susceptibility and the symmetry of electron pairing depend on the structural parameters in a nontrivial way. These results are consistent with the known experimental behavior of binary iron chalcogenides and, at the same time, reveal two promising ways of tuning superconducting transition temperatures in these materials: on one hand by expanding the iron lattice of FeSe at constant iron-selenium distance and, on the other hand, by increasing the iron-selenium distance with unchanged iron lattice.

Solid Solution, Mass Transport, and Crystal Growth Studies of Cadmium Iron Selenide.

NASA Astrophysics Data System (ADS)

Huang, Xuejun

Cadmium iron selenide, a semimagnetic semiconductor, has been investigated. Solid solubilities of iron in CdSe were determined at temperatures between 650^ circC and 1100^circC, using the X-ray diffraction Debye-Scherrer powder technique. The solubility limits of Fe in CdSe increase with the temperatures to reach a maximum of about 19.5 mole % FeSe_ {1.24} at 925^circ C, and then decrease with further increasing temperature. Solidification phenomena of the Cd-Fe-Se solid solutions were observed employing optical microscopy, which reveals a typical divorced, eutectic type, nonequilibrium solidification. The combination of the X-ray diffraction and the microscopic investigations yielded a pseudo-binary, eutectic type phase diagram of the Cd-Fe-Se system. Partial pressures of the major vapor species in the Cd-Fe-Se physical and the Cd-Fe-Se-Iodine chemical vapor transport systems were calculated. The partial pressure of gaseous iron species of the PVT system may be neglected compared to those of Cd and Se_2^ecies. This suggests that cadmium iron selenide crystals cannot be grown by the PVT method. For the PVT experiments, using the as-synthesized (CdSe)_ {0.90}(FeSe_{1.24})_{0.10 } source materials, crystals with compositions of 6-8 mole % FeSe_{1.24} were grown at a source temperature of 1000^ circC and a DeltaT of 12^circC. These result are contradictory to the thermodynamic predictions, and were further investigated employing specially purified source materials. Iron contents in the crystals grown in these experiments are close to zero. The transport of iron in the initial mass transport experiments may be due to the chemical impurities (most likely the metal chlorides) in the as-synthesized source materials. Mass transport experiments of the Cd-Fe-Se-Iodine CVT system were performed as a function of source temperatures, the degrees of undercooling (DeltaT), and initial iodine pressures. Promising parameters for the growth of cadmium iron selenide single crystals

SEPARATION OF TECHNETIUM FROM AQUEOUS SOLUTIONS BY COPRECIPITATION WITH MAGNETITE

DOEpatents

Rimshaw, S.J.

1961-10-24

A method of separating technetium in the 4+ oxidation state from an aqueous basic solution containing products of uranium fission is described. The method consists of contacting the solution with finely divided magnetite and recovering a technetium-bearing precipitate. (AEC)

Characterization of aluminum selenide bi-layer thin film

NASA Astrophysics Data System (ADS)

Boolchandani, Sarita; Soni, Gyanesh; Srivastava, Subodh; Vijay, Y. K.

2018-05-01

The Aluminum Selenide (AlSe) bi-layer thin films were grown on glass substrate using thermal evaporation method under high vacuum condition. The morphological characterization was done using SEM. Electrical measurement with temperature variation shows that thin films exhibit the semiconductor nature. The optical properties of prepared thin films have also been characterized by UV-VIS spectroscopy measurements. The band gap of composite thin films has been calculated by Tauc's relation at different temperature ranging 35°C-100°C.

The Advent of Indium Selenide: Synthesis, Electronic Properties, Ambient Stability and Applications

PubMed Central

Boukhvalov, Danil W.; Gürbulak, Bekir; Duman, Songül; Wang, Lin; Caputi, Lorenzo S.; Chiarello, Gennaro; Cupolillo, Anna

2017-01-01

Among the various two-dimensional semiconductors, indium selenide has recently triggered the interest of scientific community, due to its band gap matching the visible region of the electromagnetic spectrum, with subsequent potential applications in optoelectronics and especially in photodetection. In this feature article, we discuss the main issues in the synthesis, the ambient stability and the application capabilities of this novel class of two-dimensional semiconductors, by evidencing open challenges and pitfalls. In particular, we evidence how the growth of single crystals with reduced amount of Se vacancies is crucial in the road map for the exploitation of indium selenide in technology through ambient-stable nanodevices with outstanding values of both mobility of charge carriers and ON/OFF ratio. The surface chemical reactivity of the InSe surface, as well as applications in the fields of broadband photodetection, flexible electronics and solar energy conversion are also discussed. PMID:29113090

Sustainable p-type copper selenide solar material with ultra-large absorption coefficient

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Erica M.; Williams, Logan; Olvera, Alan

We report the synthesis of CTSe, a p-type titanium copper selenide semiconductor. Its band gap (1.15 eV) and its ultra-large absorption coefficient (10 5 cm −1 ) in the entire visible range make it a promising Earth-abundant solar absorber material.

Sustainable p-type copper selenide solar material with ultra-large absorption coefficient

DOE PAGES

Chen, Erica M.; Williams, Logan; Olvera, Alan; ...

2018-01-01

We report the synthesis of CTSe, a p-type titanium copper selenide semiconductor. Its band gap (1.15 eV) and its ultra-large absorption coefficient (10 5 cm −1 ) in the entire visible range make it a promising Earth-abundant solar absorber material.

Technetium: The First Radioelement on the Periodic Table

DOE PAGES

Johnstone, Erik V.; Yates, Mary Anne; Poineau, Frederic; ...

2017-02-21

The radioactive nature of technetium is discussed using a combination of introductory nuclear physics concepts and empirical trends observed in the chart of the nuclides and the periodic table of the elements. Trends such as the enhanced stability of nucleon pairs, magic numbers, and Mattauch's rule are described. Here, the concepts of nuclear binding energies and the nuclear shell model are introduced and used to explain the relative stability of radionuclides and, in particular, the isotopes of technetium.

Equation of state for technetium from X-ray diffraction and first-principle calculations

NASA Astrophysics Data System (ADS)

Mast, Daniel S.; Kim, Eunja; Siska, Emily M.; Poineau, Frederic; Czerwinski, Kenneth R.; Lavina, Barbara; Forster, Paul M.

2016-08-01

The ambient temperature equation of state (EoS) of technetium metal has been measured by X-ray diffraction. The metal was compressed using a diamond anvil cell and using a 4:1 methanol-ethanol pressure transmitting medium. The maximum pressure achieved, as determined from the gold pressureEquation of state for technetium from X-ray diffraction and first-principle calculations scale, was 67 GPa. The compression data shows that the HCP phase of technetium is stable up to 67 GPa. The compression curve of technetium was also calculated using first-principles total-energy calculations. Utilizing a number of fitting strategies to compare the experimental and theoretical data it is determined that the Vinet equation of state with an ambient isothermal bulk modulus of B0T=288 GPa and a first pressure derivative of B‧=5.9(2) best represent the compression behavior of technetium metal.

The Evaluation of Novel Tin Materials for the Removal of Technetium from Groundwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Kent E.; Wellman, Dawn M.

2017-06-30

Technetium-99 ( 99Tc) is present at several U.S. Department of Energy (DOE) facilities, including the Hanford, Oak Ridge, Paducah, Portsmouth, and Savannah River sites. Due to its mobility, persistence, and toxicity in the environment, developing means to immobilize and/or remove technetium from the environment is currently a top priority for DOE. However, there are currently very few approaches that effectively manage the risks of technetium to human health and the environment. The objective of this study is to evaluate novel synthetic materials that could enable direct removal of technetium from groundwater. The following report •assesses the viability of existing methodologiesmore » for synthesis of tin (II) apatite for in situ formation and remediation of 99Tc within the subsurface environment •discusses the development of alternative methodologies for production of tin (II) apatite •evaluates nanoporous tin phosphate materials for removal of technetium from groundwater.« less

Method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions

DOEpatents

Horwitz, E. Philip; Delphin, Walter H.

1979-07-24

A method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions containing these and other values by contacting the waste solution with an extractant of tricaprylmethylammonium nitrate in an inert hydrocarbon diluent which extracts the palladium and technetium values from the waste solution. The palladium and technetium values are recovered from the extractant and from any other coextracted values with a strong nitric acid strip solution.

Orbital-selective pairing and superconductivity in iron selenides

NASA Astrophysics Data System (ADS)

Nica, Emilian M.; Yu, Rong; Si, Qimiao

2017-12-01

An important challenge in condensed matter physics is understanding iron-based superconductors. Among these systems, the iron selenides hold the record for highest superconducting transition temperature and pose especially striking puzzles regarding the nature of superconductivity. The pairing state of the alkaline iron selenides appears to be of d-wave type based on the observation of a resonance mode in neutron scattering, while it seems to be of s-wave type from the nodeless gaps observed everywhere on the Fermi surface. Here we propose an orbital-selective pairing state, dubbed sτ3, as a natural explanation of these disparate properties. The pairing function, containing a matrix τ3 in the basis of 3d-electron orbitals, does not commute with the kinetic part of the Hamiltonian. This dictates the existence of both intraband and interband pairing terms in the band basis. A spin resonance arises from a d-wave-type sign change in the intraband pairing component, whereas the quasiparticle excitation is fully gapped on the FS due to an s-wave-like form factor associated with the addition in quadrature of the intraband and interband pairing terms. We demonstrate that this pairing state is energetically favored when the electron correlation effects are orbitally selective. More generally, our results illustrate how the multiband nature of correlated electrons affords unusual types of superconducting states, thereby shedding new light not only on the iron-based materials but also on a broad range of other unconventional superconductors such as heavy fermion and organic systems.

Speciation and Oxidative Stability of Alkaline Soluble, Non-Pertechnetate Technetium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levitskaia, Tatiana G.; Rapko, Brian M.; Anderson, Amity

2014-09-30

The long half-life, complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes, and high mobility in subsurface environments make technetium (Tc) one of the most difficult contaminants to dispose of and/or remediate. Technetium exists predominantly in the liquid tank waste phase as the relatively mobile form of pertechnetate, TcO 4 -. However, based on experimentation to date a significant fraction of the soluble Tc cannot be effectively separated from the wastes and may be present as a non- pertechnetate species. The presence of a non-pertechnetate species significantly complicates disposition of low-activity waste (LAW), and themore » development of methods to either convert them to pertechnetate or to separate directly is needed. The challenge is the uncertainty regarding the chemical form of the alkaline-soluble low-valent non-pertechnetate species in the liquid tank waste. This report summarizes work done in fiscal year (FY) 2014 exploring the chemistry of a low-valence technetium(I) species, [(CO) 3Tc(H 2O) 3] +, a compound of interest due to its implication in the speciation of alkaline-soluble technetium in several Hanford tank waste supernatants.« less

Deep liquid-chromatographic purification of uranium extract from technetium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volk, V.; Dvoeglazov, K; Podrezova, L.

The recycling of uranium in the nuclear fuel cycle requires the removal of a number of radioactive and stable impurities like {sup 99}Tc from spent fuels. In order to improve the grade of uranium extract purification from technetium the method of liquid chromatography and the apparatus for its performance have been developed. Process of technetium extraction and concentrating in aqueous solution containing reducing agent has been studied on simulated solutions (U-Tc-HNO{sub 3}-30% TBP-isoparM). The dynamic tests of the method have been carried out on the laboratory unit. Solution of diformyl-hydrazine in nitric acid was used as a stationary phase. Silicamore » gel with specific surface of 186 m{sup 2}/g was used as a carrier of the stationary phase. It is shown that the volume of purified extract increases as the solution temperature increases, concentration of reducing agent increases and extract flow rate decreases. It is established that the technetium content in uranium by this method could achieve a value below 0.3 ppm. Some variants of overload and composition of the stationary phase containing the extracted technetium have been offered and tested. It is defined that the method provides reduction of processing medium-active wastes by more than 10 times during finish refining process. (authors)« less

TOPO-capped silver selenide nanoparticles and their incorporation into polymer nanofibers using electrospinning technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

More, D.S.; Moloto, M.J., E-mail: makwenam@vut.ac.za; Moloto, N.

Highlights: • Ag{sub 2}Se nanoparticles produced spherical particles with sizes 12 nm (180 °C) and 27 nm (200 °C). • Higher temperature produced increased particle size (∼75 nm) and changed in shape. • Ag{sub 2}Se nanoparticles (0.2–0.6%) added into PVP (35–45%) to yield reduced fiber beading. • Polymer nanofibers electrospun at 11–20 kV produced fiber diameters of 425–461 nm. • Optical properties in the fibers were observed due to the Ag{sub 2}Se nanoparticles loaded. - Abstract: Electrospinning is the most common technique for fabricating polymer fibers as well as nanoparticles embedded polymer fibers. Silver selenide nanoparticles were synthesized using tri-n-octylphosphinemore » (TOP) as solvent and tri-n-octylphosphine oxide (TOPO) as capping environment. Silver selenide was prepared by reacting silver nitrate and selenium with tri-n-octylphosphine (TOP) to form TOP–Ag and TOP–Se solutions. Both absorption and emission spectra signify the formation of nanoparticles as well as the TEM which revealed spherical particles with an average particle size of 22 nm. The polymer, PVP used was prepared at concentrations ranging from (35 to 45 wt%) and the TOPO-capped silver selenide nanoparticles (0.2 and 0.6 wt%) were incorporated into them and electrospun by varying the voltage from 11 to 20 kV. The SEM images of the Ag{sub 2}Se/PVP composite fibers revealed the fibers of diameters with average values of 425 and 461 nm. The X-ray diffraction results show peaks which were identified due to α-Ag{sub 2}Se body centered cubic compound. The sharp peak observed for all the samples at 2θ = 44.5 suggest the presence of Ag in the face centered cubic which can be attributed to higher concentration of silver nitrate used with molar ratio of selenium to silver and the abundance of silver in the silver selenide crystal. Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA) and ultraviolet–visible spectroscopy were used to

Ba2F2Fe(1.5)Se3: An Intergrowth Compound Containing Iron Selenide Layers.

PubMed

Driss, Dalel; Janod, Etienne; Corraze, Benoit; Guillot-Deudon, Catherine; Cario, Laurent

2016-03-21

The iron selenide compound Ba2F2Fe(1.5)Se3 was synthesized by a high-temperature ceramic method. The single-crystal X-ray structure determination revealed a layered-like structure built on [Ba2F2](2+) layers of the fluorite type and iron selenide layers [Fe(1.5)Se3](2-). These [Fe1.5Se3](2-) layers contain iron in two valence states, namely, Fe(II+) and Fe(III+) located in octahedral and tetrahedral sites, respectively. Magnetic measurements are consistent with a high-spin state for Fe(II+) and an intermediate-spin state for Fe(III+). Moreover, susceptibility and resistivity measurements demonstrate that Ba2F2Fe(1.5)Se3 is an antiferromagnetic insulator.

Thermodynamics of technetium: Reconciling theory and experiment using density functional perturbation analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weck, Philippe F.; Kim, Eunja

The structure, lattice dynamics and thermodynamic properties of bulk technetium were investigated within the framework of density functional theory. The phonon density of states spectrum computed with density functional perturbation theory closely matches inelastic coherent neutron scattering measurements. The thermal properties of technetium were derived from phonon frequencies calculated within the quasi-harmonic approximation (QHA), which introduces a volume dependence of phonon frequencies as a part of the anharmonic effect. As a result, the predicted thermal expansion and isobaric heat capacity of technetium are in excellent agreement with available experimental data for temperatures up to ~1600 K.

Thermodynamics of technetium: Reconciling theory and experiment using density functional perturbation analysis

DOE PAGES

Weck, Philippe F.; Kim, Eunja

2015-06-11

The structure, lattice dynamics and thermodynamic properties of bulk technetium were investigated within the framework of density functional theory. The phonon density of states spectrum computed with density functional perturbation theory closely matches inelastic coherent neutron scattering measurements. The thermal properties of technetium were derived from phonon frequencies calculated within the quasi-harmonic approximation (QHA), which introduces a volume dependence of phonon frequencies as a part of the anharmonic effect. As a result, the predicted thermal expansion and isobaric heat capacity of technetium are in excellent agreement with available experimental data for temperatures up to ~1600 K.

Diffusion of 99-technetium in compacted bentonite under aerobic and anaerobic conditions

NASA Astrophysics Data System (ADS)

Večerník, P.; Jedináková-Křížová, V.

2006-01-01

The main aim of this study was to investigate diffusion of technetium 99Tc under different conditions. Because technetium represents one of the most dangerous fission products due to its very long halftime and high mobility in aerobic conditions diffusion experiments of technetium (as 99TcO 4 - anion) in Czech bentonite from Rokle locality have been carried out. For performance and evaluation of experiments the through-diffusion method was chosen and apparent (Da) and effective (De) diffusion coefficients were evaluated. The effects of particle mesh-size, dry bulk density and aerobic or anaerobic conditions on diffusion were studied. In the presence of oxygen, technetium occurs in oxidation state VII, as an anion, soluble and mobile in the environment. However, under reducing conditions it occurs in a lower oxidation states, mainly as insoluble oxides or hydroxides. Aerobic experiments were carried out under laboratory conditions and anaerobic experiments were performed in a nitrogen atmosphere in a glove box, to simulate the real underground conditions.

Boron selenide semiconductor detectors for thermal neutron counting

NASA Astrophysics Data System (ADS)

Kargar, Alireza; Tower, Joshua; Cirignano, Leonard; Shah, Kanai

2013-09-01

Thermal neutron detectors in planar configuration were fabricated from B2Se3 (Boron Selenide) crystals grown at RMD Inc. All fabricated semiconductor devices were characterized for the current-voltage (I-V) characteristic and neutron counting measurement. In this study, the resistivity of crystals is reported and the collected pulse height spectra are presented for devices irradiated with the 241AmBe neutron source. Long-term stability of the B2Se3 devices for neutron detection under continuous bias and without being under continuous bias was investigated and the results are reported. The B2Se3 devices showed response to thermal neutrons of the 241AmBe source.

Equation of state for technetium from X-ray diffraction and first-principle calculations

DOE PAGES

Mast, Daniel S.; Kim, Eunja; Siska, Emily M.; ...

2016-03-20

Here, the ambient temperature equation of state (EoS) of technetium metal has been measured by X-ray diffraction. The metal was compressed using a diamond anvil cell and using a 4:1 methanol-ethanol pressure transmitting medium. The maximum pressure achieved, as determined from the gold pressure scale, was 67 GPa. The compression data shows that the HCP phase of technetium is stable up to 67 GPa. The compression curve of technetium was also calculated using first-principles total-energy calculations. Utilizing a number of fitting strategies to compare the experimental and theoretical data it is determined that the Vinet equation of state with anmore » ambient isothermal bulk modulus of B 0T = 288 GPa and a first pressure derivative of B' = 5.9(2) best represent the compression behavior of technetium metal.« less

Technetium Tetrachloride Revisited: A Precursor to Lower-Valent Binary Technetium Chlorides

DOE PAGES

Johnstone, Erik V.; Poineau, Frederic; Forster, Paul M.; ...

2012-07-09

Technetium (Tc) is the lightest element that doesn't occur in nature. At UNLV, our radiochemistry program gives us access to Tc and the ability to make various Tc compounds. Here we describe the preparation and characterization of TcCl 4. The Tc atom is found to have a magnetic moment and magnetically orders at low temperature. As discerning trends in the transition metals, of which Tc is one, is important for understanding all transition metal compounds, this research is relevant to understanding these materials.

Copper Selenide Nanocrystals for Photothermal Therapy

PubMed Central

Hessel, Colin M.; Pattani, Varun; Rasch, Michael; Panthani, Matthew G.; Koo, Bonil; Tunnell, James W.; Korgel, Brian A.

2011-01-01

Ligand-stabilized copper selenide (Cu2−xSe) nanocrystals, approximately 16 nm in diameter, were synthesized by a colloidal hot injection method and coated with amphiphilic polymer. The nanocrystals readily disperse in water and exhibit strong near infrared (NIR) optical absorption with a high molar extinction coefficient of 7.7 × 107 cm−1 M−1 at 980 nm. When excited with 800 nm light, the Cu2−xSe nanocrystals produce significant photothermal heating with a photothermal transduction efficiency of 22%, comparable to nanorods and nanoshells of gold (Au). In vitro photothermal heating of Cu2−xSe nanocrystals in the presence of human colorectal cancer cell (HCT-116) led to cell destruction after 5 minutes of laser irradiation at 33 W/cm2, demonstrating the viabilitiy of Cu2−xSe nanocrystals for photothermal therapy applications. PMID:21553924

99M-Technetium labeled tin colloid radiopharmaceuticals

DOEpatents

Winchell, Harry S.; Barak, Morton; Van Fleet, III, Parmer

1976-07-06

An improved 99m-technetium labeled tin(II) colloid, size-stabilized for reticuloendothelial organ imaging without the use of macromolecular stabilizers and a packaged tin base reagent and an improved method for making it are disclosed.

Depression-like behavior and mechanical allodynia are reduced by bis selenide treatment in mice with chronic constriction injury: a comparison with fluoxetine, amitriptyline, and bupropion.

PubMed

Jesse, Cristiano R; Wilhelm, Ethel A; Nogueira, Cristina W

2010-12-01

Neuropathic pain is associated with significant co-morbidities, including depression, which impact considerably on the overall patient experience. Pain co-morbidity symptoms are rarely assessed in animal models of neuropathic pain. Neuropathic pain is characterized by hyperexcitability within nociceptive pathways and remains difficult to treat with standard analgesics. The present study determined the effect of bis selenide and conventional antidepressants (fluoxetine, amitriptyline, and bupropion) on neuropathic pain using mechanical allodynic and on depressive-like behavior. Male mice were subjected to chronic constriction injury (CCI) or sham surgery and were assessed on day 14 after operation. Mice received oral treatment with bis selenide (1-5 mg/kg), fluoxetine, amitriptyline, or bupropion (10-30 mg/kg). The response frequency to mechanical allodynia in mice was measured with von Frey hairs. Mice were evaluated in the forced swimming test (FST) test for depression-like behavior. The CCI procedure produced mechanical allodynia and increased depressive-like behavior in the FST. All of the drugs produced antiallodynic effects in CCI mice and produced antidepressant effects in control mice without altering locomotor activity. In CCI animals, however, only the amitriptyline and bis selenide treatments significantly reduced immobility in the FST. These data demonstrate an important dissociation between the antiallodynic and antidepressant effects in mice when tested in a model of neuropathic pain. Depressive behavior in CCI mice was reversed by bis selenide and amitriptyline but not by the conventional antidepressants fluoxetine and buproprion. Bis selenide was more potent than the other drugs tested for antidepressant-like and antiallodynic effects in mice.

Chemical Potential Tuning and Enhancement of Thermoelectric Properties in Indium Selenides.

PubMed

Rhyee, Jong-Soo; Kim, Jin Hee

2015-03-20

Researchers have long been searching for the materials to enhance thermoelectric performance in terms of nano scale approach in order to realize phonon-glass-electron-crystal and quantum confinement effects. Peierls distortion can be a pathway to enhance thermoelectric figure-of-merit ZT by employing natural nano-wire-like electronic and thermal transport. The phonon-softening known as Kohn anomaly, and Peierls lattice distortion decrease phonon energy and increase phonon scattering, respectively, and, as a result, they lower thermal conductivity. The quasi-one-dimensional electrical transport from anisotropic band structure ensures high Seebeck coefficient in Indium Selenide. The routes for high ZT materials development of In₄Se₃ - δ are discussed from quasi-one-dimensional property and electronic band structure calculation to materials synthesis, crystal growth, and their thermoelectric properties investigations. The thermoelectric properties of In₄Se₃ - δ can be enhanced by electron doping, as suggested from the Boltzmann transport calculation. Regarding the enhancement of chemical potential, the chlorine doped In₄Se₃ - δ Cl 0.03 compound exhibits high ZT over a wide temperature range and shows state-of-the-art thermoelectric performance of ZT = 1.53 at 450 °C as an n -type material. It was proven that multiple elements doping can enhance chemical potential further. Here, we discuss the recent progress on the enhancement of thermoelectric properties in Indium Selenides by increasing chemical potential.

Bis(dicyclohexylselenophosphinyl)selenide, [Cy2P(Se)]2Se: Synthesis, molecular structure and application for self-assembly of a tetrahedral Cu(I) cluster

NASA Astrophysics Data System (ADS)

Artem'ev, Alexander V.; Doronina, Evgeniya P.; Bagryanskaya, Irina Yu; Klyba, Lyudmila V.

2018-05-01

The molecular structure of the selenides of [R2P(Se)]2Se type has been systematically studied on example of bis(dicyclohexylselenophosphinyl)selenide, [Cy2P(Se)]2Se. This selenide has been synthesized in 65% yield by oxidation of Cy2PH with elemental selenium in 1:2 M ratio. Its structure has been investigated by X-ray diffractometry (XRD), NMR, FT-IR and MALDI-TOF/MS techniques. In the solid, the Se1sbnd Psbnd Se2sbnd Psbnd Se3 chain of (Cy2P = Se)2Se molecule adopts a syn-anti conformation with the Se1sbnd Psbnd Se2sbnd P and Psbnd Se2sbnd Psbnd Se3 torsion angles of -179.64 (3)° and 4.69 (4)°. The vibrational band assignments, performing at B3LYP/6-311++G (d,p) theory level, are in a good agreement with the experimental FT-IR frequencies. The synthetic utility of the prepared selenide has been exemplified by its reaction with CuCl2 resulted in the formation of [Cu4(Se2PCy2)4] cluster in 53% yield. The structure of latter is formed by a Cu4 tetrahedron, wherein each triangular face is bridged by a [Se2PCy2] ligand in a trimetallic triconnective (μ2, μ1) pattern.

Non-pertechnetate Technetium Sensor Research and Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Samuel A.; Rapko, Brian M.; Branch, Shirmir D.

Several significant uncertainties remain regarding the understanding and modeling of the fate and speciation of technicium-99 ( 99Tc) in Hanford waste tanks, glass, and low-temperature waste forms. A significant (2% to 25%) fraction of the 99Tc in the water-soluble portion of the tank waste may be present as one or more non pertechnetate species that have not been identified and to date, cannot be effectively separated from the wastes. This task will provide a sensor specifically tuned to detect the Tc(I)-carbonyl species believed to constitute the main fraction of the non-pertechnetate form of technetium. By direct measurement of the non-pertechnetatemore » species, such a sensor will help reduce the uncertainties in the modeling of the fate and speciation of 99Tc in Hanford tanks and waste forms. This report summarizes work performed in FY2016 that was sponsored by the Department of Energy’s Office of Environmental Management and demonstrates the protocol for using fluorescent Tc(I)-tricarbonyl complex as a means to detect the non-pertechnetate species within tank waste solutions. The protocol was optimized with respect to ligand concentration, solvent choice, reaction temperature and time. This work culminated in the quantitation of Tc(I)-tricarbonyl within a waste simulant, using a standard addition method for measurement. This report also summarizes the synthesis and high-yield preparation of the low-valence technetium species, [Tc(CO) 3(H 2O) 3] +, which will be used as the technetium standard material for the demonstration of the non-pertechnetate species in actual wastes.« less

Chemical Potential Tuning and Enhancement of Thermoelectric Properties in Indium Selenides

PubMed Central

Rhyee, Jong-Soo; Kim, Jin Hee

2015-01-01

Researchers have long been searching for the materials to enhance thermoelectric performance in terms of nano scale approach in order to realize phonon-glass-electron-crystal and quantum confinement effects. Peierls distortion can be a pathway to enhance thermoelectric figure-of-merit ZT by employing natural nano-wire-like electronic and thermal transport. The phonon-softening known as Kohn anomaly, and Peierls lattice distortion decrease phonon energy and increase phonon scattering, respectively, and, as a result, they lower thermal conductivity. The quasi-one-dimensional electrical transport from anisotropic band structure ensures high Seebeck coefficient in Indium Selenide. The routes for high ZT materials development of In4Se3−δ are discussed from quasi-one-dimensional property and electronic band structure calculation to materials synthesis, crystal growth, and their thermoelectric properties investigations. The thermoelectric properties of In4Se3−δ can be enhanced by electron doping, as suggested from the Boltzmann transport calculation. Regarding the enhancement of chemical potential, the chlorine doped In4Se3−δCl0.03 compound exhibits high ZT over a wide temperature range and shows state-of-the-art thermoelectric performance of ZT = 1.53 at 450 °C as an n-type material. It was proven that multiple elements doping can enhance chemical potential further. Here, we discuss the recent progress on the enhancement of thermoelectric properties in Indium Selenides by increasing chemical potential. PMID:28788002

Separation of uranium from technetium in recovery of spent nuclear fuel

DOEpatents

Friedman, Horace A.

1985-01-01

A method for decontaminating uranium product from the Purex process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO.sub.2.sup.2+) uranium and heptavalent technetium (TcO.sub.4 -). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H.sub.2 C.sub.2 O.sub.4), and the Tc-oxalate complex is readily separated from the uranium by solvent extraction with 30 vol. % tributyl phosphate in n-dodecane.

Synthesis and characterization of nanostructured bismuth selenide thin films.

PubMed

Sun, Zhengliang; Liufu, Shengcong; Chen, Lidong

2010-12-07

Nanostructured bismuth selenide thin films have been successfully fabricated on a silicon substrate at low temperature by rational design of the precursor solution. Bi(2)Se(3) thin films were constructed of coalesced lamella in the thickness of 50-80 nm. The nucleation and growth process of Bi(2)Se(3) thin films, as well as the influence of solution chemistry on the film structure were investigated in detail. As one of the most promising thermoelectric materials, the thermoelectric properties of the prepared Bi(2)Se(3) thin films were also investigated. The power factor increased with increasing carrier mobility, coming from the enlarged crystallites and enhanced coalesced structure, and reached 1 μW cm(-1) K(-1).

Thermochemically evolved nanoplatelets of bismuth selenide with enhanced thermoelectric figure of merit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ali, Zulfiqar; Cao, Chuanbao, E-mail: cbcao@bit.edu.cn; Butt, Faheem K.

We firstly present a simple thermochemical method to fabricate high-quality Bi{sub 2}Se{sub 3} nanoplatelets with enhanced figure of merit using elemental bismuth and selenium powders as precursors. The crystal structure of as synthesized products is characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM) measurements. Morphological and chemical synthetic parameters are investigated through a series of experiments; thickness and composition of the platelets are well controlled in large scale production. Subsequently spark plasma sintering (SPS) is performed to fabricate n-type nanostructured bulk thermoelectric materials. Raman Spectroscopy of the two selected samples with approximatelymore » of 50 and 100 nm thicknesses shows three vibrational modes. The lower thickness sample exhibits the maximum red shift of about 2.17 cm{sup -1} and maximum broadening of about 10 cm{sup -1} by in-plane vibrational mode E{sup 2}{sub g}. The enhanced value of figure of merit ∼0.41 is obtained for pure phase bismuth selenide to the best of our knowledge. We observe metallic conduction behavior while semiconducting behavior for nanostructured bismuth selenide is reported elsewhere which could be due to different synthetic techniques adopted. These results clearly suggest that our adopted synthetic technique has profound effect on the electronic and thermoelectric transport properties of this material.« less

Synthesis and characterization of luminescent aluminium selenide nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balitskii, O.A., E-mail: balitskii@electronics.wups.lviv.ua; Demchenko, P.Yu.; Mijowska, E.

Highlights: ► Synthesis procedure of size and sharp controlled Al{sub 2}Se{sub 3} nanocrystals is introduced. ► Obtained nanoparticles are highly crystalline of hexagonal wurtzite type. ► Colloidal Al{sub 2}Se{sub 3} nanocrystals are highly luminescent in the near UV spectral region. ► They can be implemented in light emitters/collectors, concurring with II–VI nanodots. -- Abstract: We propose the synthesis and characterization of colloidal aluminium selenide nanocrystals using trioctylphosphine as a solvent. The nanoparticles have several absorption bands in the spectral region 330–410 nm and are bright UV-blue luminescent, which is well demanded in light collecting and emitting devices, e.g. for tuningmore » their spectral characteristics to higher energy solar photons.« less

APPLICATION OF FORMOHYDROXAMIC ACID IN NUCLEAR PROCESSING: SYNTHESIS AND COMPLEXATION WITH TECHNETIUM-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amber Wright; Edward Mausolf; Keri Campbell

2010-05-01

Acetohydroxamic acid (AHA) is an organic ligand planned for use in the Uranium Extraction (UREX) process. It reduces neptunium and plutonium, and the resultant hydrophilic complexes are separated from uranium by extraction with tributyl phosphate (TBP) in a hydrocarbon diluent. AHA undergoes hydrolysis to acetic acid which will impede the recycling of nitric acid. During recent discussions of the UREX process, it has been proposed to replace AHA by formohydroxamic acid (FHA). FHA will undergo hydrolysis to formic acid which is volatile, thus allowing the recycling of nitric acid. The reported reduction potentials of AHA and pertechnetate (TcO{sub 4}{sup -})more » indicated that it may be possible for AHA to reduce technetium, altering its fate in the fuel cycle. At UNLV, it has been demonstrated that TcO{sub 4}{sup -} undergoes reductive nitrosylation by AHA under a variety of conditions. The resulting divalent technetium is complexed by AHA to form the pseudo-octahedral trans-aquonitrosyl (diacetohydroxamic)-technetium(II) complex ([Tc{sup II}(NO)(AHA){sub 2}H{sub 2}O]{sup +}). In this paper, we are reporting the synthesis of FHA and its complex formation with technetium along with the characterization of FHA crystals achieved by NMR and IR spectroscopy. Two experiments were conducted to investigate the complexation of FHA with Tc and the results were compared with previous data on AHA. The first experiment involved the elution of Tc from a Reillex HP anion exchange resin, and the second one monitored the complexation of technetium with FHA by UV-visible spectrophotometry.« less

Separation of uranium from technetium in recovery of spent nuclear fuel

DOEpatents

Friedman, H.A.

1984-06-13

A method for decontaminating uranium product from the Purex 5 process comprises addition of hydrazine to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO/sub 2//sup 2 +/) uranium and heptavalent technetium (TcO/sub 4/-). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H/sub 2/C/sub 2/O/sub 4/), and the Tc-oxalate complex is readily separated from the 10 uranium by solvent extraction with 30 vol % tributyl phosphate in n-dodecane.

Ovonic switching in tin selenide thin films. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Baxter, C. R.

1974-01-01

Amorphous tin selenide thin films which possess Ovonic switching properties were fabricated using vacuum deposition techniques. Results obtained indicate that memory type Ovonic switching does occur in these films the energy density required for switching from a high impedance to a low impedance state is dependent on the spacing between the electrodes of the device. The switching is also function of the magnitude of the applied voltage pulse. A completely automated computer controlled testing procedure was developed which allows precise control over the shape of the applied voltage switching pulse. A survey of previous experimental and theoretical work in the area of Ovonic switching is also presented.

Investigation of radioactivity concentration in spent technetium generators

NASA Astrophysics Data System (ADS)

Idriss, Hajo; Salih, Isam; Alaamer, Abdulaziz S.; Eisa, M. H.; Sam, A. K.

2014-04-01

This study was carried out to survey and measure radioactivity concentration and estimate radiation dose level at the surface of spent technetium generator columns for the safe final disposal of radioactive waste. High resolution γ-spectrometry with the aid of handheld radiation survey meters has been used. The radioactivity measurements has shown that 238U, 40K and 137Cs were only measurable in one sample whereas 125Sb was found in 14 samples out of total of 20 samples with an activity concentration which ranged from 21 to 7404 with an average value of 1095 Bq/kg. The activity concentration of 125Sb is highly variable indicating that the spent 99mTc generator columns are of different origin. This investigation highlighted the importance of radiation monitoring of spent technetium generators in the country in order to protect workers, and the public from the dangers posed by radioactive waste.

Inorganic fullerene-like molybdenum selenide with good biocompatibility synthesized by laser ablation in liquids

NASA Astrophysics Data System (ADS)

Wu, Xiaoju; Tian, Xiumei; Chen, Tongming; Zeng, Ao; Yang, Guowei

2018-07-01

The fabrication of inorganic fullerene-like nanoparticles (IFNPs) is an attractive idea due to their unique structures and various potential applications. To date, IFNPs have been made from numerous compounds with layered two-dimensional structures, based on various synthetic methods. Here we have demonstrated for the first time that inorganic fullerene-like molybdenum selenide nanoparticles (MoSe2 IFNPs) can be synthesized by laser ablating a molybdenum selenide target in 30 vol % ethanol/water mixture at ambient temperature and pressure. The formation mechanism was proposed to elucidate the production of MoSe2 IFNPs in the process of laser ablation in liquids (LAL). The appropriate solvent facilitates the condensation of the plasma plume created by LAL to planar MoSe2. Then, laser-induced high temperature and high pressure lead to the formation of a vacancy in the planar MoSe2, causing the generation of nucleation and growth of the MoSe2 IFNPs. In addition, a CCK-8 (cell counting kit-8) assay and a cell viability assay were performed to examine the cytotoxic behavior and the effect on cell viability of MoSe2 IFNPs. The results show that MoSe2 IFNPs are reasonably nontoxic and biocompatible with the given cells, showing they have significant potential in biomedical applications.

Transparent metal selenide alloy counter electrodes for high-efficiency bifacial dye-sensitized solar cells.

PubMed

Duan, Yanyan; Tang, Qunwei; Liu, Juan; He, Benlin; Yu, Liangmin

2014-12-22

The exploration of cost-effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye-sensitized solar cells (DSSCs). Transparent counter electrodes based on binary-alloy metal selenides (M-Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution-based method and employed in efficient bifacial DSSCs. Owing to superior charge-transfer ability for the I(-) /I3 (-) redox couple, electrocatalytic activity toward I3 (-) reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30 % and 4.63 % for Co0.85 Se, 7.85 % and 4.37 % for Ni0.85 Se, 6.43 % and 4.24 % for Cu0.50 Se, 7.64 % and 5.05 % for FeSe, and 9.22 % and 5.90 % for Ru0.33 Se in comparison with 6.18 % and 3.56 % for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inorganic fullerene-like molybdenum selenide with good biocompatibility synthesized by laser ablation in liquids.

PubMed

Wu, Xiaoju; Tian, Xiumei; Chen, Tongming; Zeng, Ao; Yang, Guowei

2018-07-20

The fabrication of inorganic fullerene-like nanoparticles (IFNPs) is an attractive idea due to their unique structures and various potential applications. To date, IFNPs have been made from numerous compounds with layered two-dimensional structures, based on various synthetic methods. Here we have demonstrated for the first time that inorganic fullerene-like molybdenum selenide nanoparticles (MoSe 2 IFNPs) can be synthesized by laser ablating a molybdenum selenide target in 30 vol % ethanol/water mixture at ambient temperature and pressure. The formation mechanism was proposed to elucidate the production of MoSe 2 IFNPs in the process of laser ablation in liquids (LAL). The appropriate solvent facilitates the condensation of the plasma plume created by LAL to planar MoSe 2 . Then, laser-induced high temperature and high pressure lead to the formation of a vacancy in the planar MoSe 2 , causing the generation of nucleation and growth of the MoSe 2 IFNPs. In addition, a CCK-8 (cell counting kit-8) assay and a cell viability assay were performed to examine the cytotoxic behavior and the effect on cell viability of MoSe 2 IFNPs. The results show that MoSe 2 IFNPs are reasonably nontoxic and biocompatible with the given cells, showing they have significant potential in biomedical applications.

Solubility Control of Technetium Release from Saltstone by Tc02•xH20

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Kirk J.; Williams, Benjamin D.

2013-11-12

Saltstone leaching experiments were conducted using a modified single-pass flow-through method under anoxic conditions. The analytical results of leachates collected from these experiments were evaluated using thermodynamic modeling to determine if the data were consistent with potential solubility controlling phases. The results demonstrate that technetium concentrations in water in contact with Saltstone under anoxic conditions is controlled by the solubility of TcO2•xH2O (likely TcO2•1.6H2O). In our system equilibrium solubility appears to have been reached within two weeks at a concentration of approximately 1.5 x 10-6 M. This concentration is likely to vary as the composition of Saltstone pore fluid evolvesmore » over time. As the pH goes from the initial high values (~12.5-13) to lower values, the solubility of technetium will decrease significantly. The thermodynamic data used to determine the solubility of TcO2•1.6H2O were taken from the tabulation of critically selected thermodynamic data determined by the Nuclear Energy Agency. Solid phase characterization to demonstrate the presence of TcO2•xH2O was not possible due to the low concentrations of technetium in our samples. Previous solid phase characterization studies with cementitious waste forms that were very similar to our Saltstone samples as well as reaction products derived from reductive immobilization of TcO4- by amorphous FeS clearly indicate the presence of TcO2 with varying degrees of hydration. Although, the presence of TcSx or other reduced technetium sulfide phases in our samples cannot be ruled out, release of technetium from Saltstone will be controlled by TcO2•1.6H2O because of its higher solubility. Our results clearly demonstrate that the release mechanism of technetium from Saltstone under reducing conditions is solubility controlled by TcO2•xH2O (likely TcO2•1.6H2O); however, distribution coefficients (Kds), that describe sorption and not solubility, were calculated

Development of Alternative Technetium Waste Forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czerwinski, Kenneth

2013-09-13

The UREX+1 process is under consideration for the separation of transuranic elements from spent nuclear fuel. The first steps of this process extract the fission product technicium-99 ({sup 99}Tc) into an organic phase containing tributylphosphate together with uranium. Treatment of this stream requires the separation of Tc from U and placement into a suitable waste storage form. A potential candidate waste form involves immobilizing the Tc as an alloy with either excess metallic zirconium or stainless steel. Although Tc-Zr alloys seem to be promising waste forms, alternative materials must be investigated. Innovative studies related to the synthesis and behavior ofmore » a different class of Tc materials will increase the scientific knowledge related to development of Tc waste forms. These studies will also provide a better understanding of the behavior of {sup 99}Tc in repository conditions. A literature survey has selected promising alternative waste forms for further study: technetium metallic alloys, nitrides, oxides, sulfides, and pertechnetate salts. The goals of this project are to 1) synthesize and structurally characterize relevant technetium materials that may be considered as waste forms, 2) investigate material behavior in solution under different conditions of temperature, electrochemical potential, and radiation, and 3) predict the long-term behavior of these materials.« less

Room temperature chemical bath deposition of cadmium selenide, cadmium sulfide and cadmium sulfoselenide thin films with novel nanostructures

NASA Astrophysics Data System (ADS)

VanderHyde, Cephas A.; Sartale, S. D.; Patil, Jayant M.; Ghoderao, Karuna P.; Sawant, Jitendra P.; Kale, Rohidas B.

2015-10-01

A simple, convenient and low cost chemical synthesis route has been used to deposit nanostructured cadmium sulfide, selenide and sulfoselenide thin films at room temperature. The films were deposited on glass substrates, using cadmium acetate as cadmium ion and sodium selenosulfate/thiourea as a selenium/sulfur ion sources. Aqueous ammonia was used as a complex reagent and also to adjust the pH of the final solution. The as-deposited films were uniform, well adherent to the glass substrate, specularly reflective and red/yellow in color depending on selenium and sulfur composition. The X-ray diffraction pattern of deposited cadmium selenide thin film revealed the nanocrystalline nature with cubic phase; cadmium sulfide revealed mixture of cubic along with hexagonal phase and cadmium sulfoselenide thin film were grown with purely hexagonal phase. The morphological observations revealed the growth and formation of interesting one, two and three-dimensional nanostructures. The band gap of thin films was calculated and the results are reported.

Technetium: The First Radioelement on the Periodic Table

ERIC Educational Resources Information Center

Johnstone, Erik V.; Yates, Mary Anne; Poineau, Frederic; Sattelberger, Alfred P.; Czerwinski, Kenneth R.

2017-01-01

The radioactive nature of technetium is discussed using a combination of introductory nuclear physics concepts and empirical trends observed in the chart of the nuclides and the periodic table of the elements. Trends such as the enhanced stability of nucleon pairs, magic numbers, and Mattauch's rule are described. The concepts of nuclear binding…

Facile Route to Rare Heterobimetallic Aluminum-Copper and Aluminum-Zinc Selenide Clusters.

PubMed

Li, Bin; Li, Jiancheng; Liu, Rui; Zhu, Hongping; Roesky, Herbert W

2017-03-20

Heterobimetallic aluminum-copper and aluminum-zinc clusters were prepared from the reaction of LAl(SeH) 2 [1; L = HC(CMeNAr) 2 and Ar = 2,6-iPr 2 C 6 H 3 ] with (MesCu) 4 and ZnEt 2 , respectively. The resulting clusters with the core structures of Al 2 Se 4 Cu 4 and Al 2 Se 4 Zn 3 exhibit unique metal-organic frameworks. This is a novel pathway for the synthesis of aluminum-copper and aluminum-zinc selenides. The products have been characterized by spectroscopic methods and single-crystal X-ray structural characterization.

Selenide isotope generator for the Galileo mission. Reliability program plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-10-01

The reliability program plan for the Selenide Isotope Generator (SIG) program is presented. It delineates the specific tasks that will be accomplished by Teledyne Energy Systems and its suppliers during design, development, fabrication and test of deliverable Radioisotopic Thermoelectric Generators (RTG), Electrical Heated Thermoelectric Generators (ETG) and associated Ground Support Equipment (GSE). The Plan is formulated in general accordance with procedures specified in DOE Reliability Engineering Program Requirements Publication No. SNS-2, dated June 17, 1974. The Reliability Program Plan presented herein defines the total reliability effort without further reference to Government Specifications. The reliability tasks to be accomplished are delineatedmore » herein and become the basis for contract compliance to the extent specified in the SIG contract Statement of Work.« less

Carbon-Supported Nickel Selenide Hollow Nanowires as Advanced Anode Materials for Sodium-Ion Batteries.

PubMed

Yang, Xuming; Zhang, Jiaolong; Wang, Zhenguang; Wang, Hongkang; Zhi, Chunyi; Yu, Denis Y W; Rogach, Andrey L

2018-02-01

Carbon-supported nickel selenide (Ni 0.85 Se/C) hollow nanowires are prepared from carbon-coated selenium nanowires via a self-templating hydrothermal method, by first dissolving selenium in the Se/C nanowires in hydrazine, allowing it to diffuse out of the carbon layer, and then reacting with nickel ions into Ni 0.85 Se nanoplates on the outer surface of the carbon. Ni 0.85 Se/C hollow nanowires are employed as anode materials for sodium-ion batteries, and their electrochemical performance is evaluated via the cyclic voltammetry and electrochemical impedance spectroscopy combined with ex situ X-ray photoelectron spectroscopy and X-ray diffraction measurements. It is found that Ni 0.85 Se/C hollow nanowires exhibit greatly enhanced cycle stability and rate capability as compared to Ni 0.85 Se nanoparticles, with a reversible capacity around 390 mA h g -1 (the theoretical capacity is 416 mA h g -1 ) at the rate of 0.2 C and 97% capacity retention after 100 cycles. When the current rate is raised to 5 C, they still deliver capacity of 219 mA h g -1 . The synthetic methodology introduced here is general and can easily be applied to building similar structures for other metal selenides in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immobilization and Limited Reoxidation of Technetium-99 by Fe(II)-Goethite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Chang, Hyun-shik; Icenhower, Jonathan P.

2010-09-30

This report summarizes the methodology used to test the sequestration of technetium-99 present in both deionized water and simulated Hanford Tank Waste Treatment and Immobilization Plant waste solutions.

In situ transmission electron microscopy of cadmium selenide nanorod sublimation

DOE PAGES

Hellebusch, Daniel J.; Manthiram, Karthish; Beberwyck, Brandon J.; ...

2015-01-23

In situ electron microscopy is used to observe the morphological evolution of cadmium selenide nanorods as they sublime under vacuum at a series of elevated temperatures. Mass loss occurs anisotropically along the nanorod’s long axis. At temperatures close to the sublimation threshold, the phase change occurs from both tips of the nanorods and proceeds unevenly with periods of rapid mass loss punctuated by periods of relative stability. At higher temperatures, the nanorods sublime at a faster, more uniform rate, but mass loss occurs from only a single end of the rod. Furthermore, we propose a mechanism that accounts for themore » observed sublimation behavior based on the terrace–ledge–kink (TLK) model and how the nanorod surface chemical environment influences the kinetic barrier of sublimation.« less

Assessment of the Cast Stone Low-Temperature Waste Form Technology Coupled with Technetium Removal - 14379

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Christopher F.; Rapko, Brian M.; Serne, R. Jeffrey

2014-03-03

The U.S. Department of Energy Office of Environmental Management (EM) is engaging the national laboratories to provide the scientific and technological rigor to support EM program and project planning, technology development and deployment, project execution, and assessment of program outcomes. As an early demonstration of this new responsibility, Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) were chartered to implement a science and technology program addressing low-temperature waste forms for immobilization of DOE aqueous waste streams, including technetium removal as an implementing technology. As a first step, the laboratories examined the technical risks and uncertainties associated withmore » the Cast Stone waste immobilization and technetium removal projects at Hanford. Science and technology gaps were identified for work associated with 1) conducting performance assessments and risk assessments of waste form and disposal system performance, and 2) technetium chemistry in tank wastes and separation of technetium from waste processing streams. Technical approaches to address the science and technology gaps were identified and an initial sequencing priority was suggested. A subset of research was initiated in 2013 to begin addressing the most significant science and technology gaps. The purpose of this paper is to report progress made towards closing these gaps and provide notable highlights of results achieved to date.« less

Simultaneous phase and morphology controllable synthesis of copper selenide films by microwave-assisted nonaqueous approach

NASA Astrophysics Data System (ADS)

Li, Jing; Fa, Wenjun; Li, Yasi; Zhao, Hongxiao; Gao, Yuanhao; Zheng, Zhi

2013-02-01

Copper selenide films with different phase and morphology were synthesized on copper substrate through controlling reaction solvent by microwave-assisted nonaqueous approach. The films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that the pure films could be obtained using cyclohexyl alcohol or benzyl alcohol as solvent. The cubic Cu2-xSe dendrites were synthesized in cyclohexyl alcohol reaction system and hexagonal CuSe flaky crystals were obtained with benzyl alcohol as solvent.

Tin Selenide (SnSe): Growth, Properties, and Applications

PubMed Central

Shi, Weiran; Gao, Minxuan; Wei, Jinping; Gao, Jianfeng; Fan, Chenwei; Ashalley, Eric; Wang, Zhiming

2018-01-01

Abstract The indirect bandgap semiconductor tin selenide (SnSe) has been a research hotspot in the thermoelectric fields since a ZT (figure of merit) value of 2.6 at 923 K in SnSe single crystals along the b‐axis is reported. SnSe has also been extensively studied in the photovoltaic (PV) application for its extraordinary advantages including excellent optoelectronic properties, absence of toxicity, cheap raw materials, and relative abundance. Moreover, the thermoelectric and optoelectronic properties of SnSe can be regulated by the structural transformation and appropriate doping. Here, the studies in SnSe research, from its evolution to till now, are reviewed. The growth, characterization, and recent developments in SnSe research are discussed. The most popular growth techniques that have been used to prepare SnSe materials are discussed in detail with their recent progress. Important phenomena in the growth of SnSe as well as the problems remaining for future study are discussed. The applications of SnSe in the PV fields, Li‐ion batteries, and other emerging fields are also discussed. PMID:29721411

Tin Selenide (SnSe): Growth, Properties, and Applications.

PubMed

Shi, Weiran; Gao, Minxuan; Wei, Jinping; Gao, Jianfeng; Fan, Chenwei; Ashalley, Eric; Li, Handong; Wang, Zhiming

2018-04-01

The indirect bandgap semiconductor tin selenide (SnSe) has been a research hotspot in the thermoelectric fields since a ZT (figure of merit) value of 2.6 at 923 K in SnSe single crystals along the b -axis is reported. SnSe has also been extensively studied in the photovoltaic (PV) application for its extraordinary advantages including excellent optoelectronic properties, absence of toxicity, cheap raw materials, and relative abundance. Moreover, the thermoelectric and optoelectronic properties of SnSe can be regulated by the structural transformation and appropriate doping. Here, the studies in SnSe research, from its evolution to till now, are reviewed. The growth, characterization, and recent developments in SnSe research are discussed. The most popular growth techniques that have been used to prepare SnSe materials are discussed in detail with their recent progress. Important phenomena in the growth of SnSe as well as the problems remaining for future study are discussed. The applications of SnSe in the PV fields, Li-ion batteries, and other emerging fields are also discussed.

Effects of concurrent drug therapy on technetium /sup 99m/Tc gluceptate biodistribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinkle, G.H.; Basmadjian, G.P.; Peek, C.

Drug interactions with /sup 99m/Tc gluceptate resulting in altered biodistribution were studied using chart review and animal tests. Charts of nine patients who had abnormal gallbladder uptake of technetium /sup 99m/Tc gluceptate during a two-year period were reviewed to obtain data such as concurrent drug therapy, primary diagnosis, and laboratory values. Adult New Zealand white rabbits were then used for testing the biodistribution of technetium /sup 99m/Tc gluceptate when administered concurrently with possibly interacting drugs identified in the chart review--penicillamine, penicillin G potassium, penicillin V potassium, acetaminophen, and trimethoprim-sulfamethoxazole. Chart review revealed no conclusive patterns of altered biodistribution associated withmore » other factors. The data did suggest the possibility that the five drugs listed above might cause increased hepatobiliary clearance of the radiopharmaceutical. Animal tests showed that i.v. penicillamine caused substantial distribution of radioactivity into the gallbladder and small bowel. Minimally increased gallbladder radioactivity occurred when oral acetaminophen and trimethoprim-sulfamethoxazole were administered concurrently. Oral and i.v. penicillins did not increase gallbladder activity. Penicillamine may cause substantial alteration of the biodistribution of technetium /sup 99m/Tc gluceptate.« less

Technetium and rhenium pentacarbonyl complexes with C₂ and C₁₁ ω-isocyanocarboxylic acid esters.

PubMed

Miroslavov, Alexander E; Polotskii, Yuriy S; Gurzhiy, Vladislav V; Ivanov, Alexander Yu; Lumpov, Alexander A; Tyupina, Margarita Yu; Sidorenko, Georgy V; Tolstoy, Peter M; Maltsev, Daniil A; Suglobov, Dmitry N

2014-08-04

Technetium(I) and rhenium(I) pentacarbonyl complexes with ethyl 2-isocyanoacetate and methyl 11-isocyanoundecanoate, [M(CO)5(CNCH2COOEt)]ClO4 (M = Tc (1) and Re (2)) and [M(CO)5(CN(CH2)10COOMe)]ClO4 (M = Tc (3) and Re (4)), were prepared and characterized by IR, (1)H NMR, and (13)C{(1)H} NMR spectroscopy. The crystal structures of 1 and 2 were determined using single-crystal X-ray diffraction. The kinetics of thermal decarbonylation of technetium complexes 1 and 3 in ethylene glycol was studied by IR spectroscopy. The rate constants and activation parameters of this reaction were determined and compared with those for [Tc(CO)6](+). It was found that rhenium complexes 2 and 4 were stable with respect to thermal decarbonylation. Histidine challenge reaction of complexes 1 and 2 in phosphate buffer was examined by IR spectroscopy. In the presence of histidine, the rhenium pentacarbonyl isocyanide complex partially decomposes to form an unidentified yellow precipitate. Technetium analogue 1 is more stable under these conditions.

Liquid-like cationic sub-lattice in copper selenide clusters

NASA Astrophysics Data System (ADS)

White, Sarah L.; Banerjee, Progna; Jain, Prashant K.

2017-02-01

Super-ionic solids, which exhibit ion mobilities as high as those in liquids or molten salts, have been employed as solid-state electrolytes in batteries, improved thermoelectrics and fast-ion conductors in super-capacitors and fuel cells. Fast-ion transport in many of these solids is supported by a disordered, `liquid-like' sub-lattice of cations mobile within a rigid anionic sub-lattice, often achieved at high temperatures or pressures via a phase transition. Here we show that ultrasmall clusters of copper selenide exhibit a disordered cationic sub-lattice under ambient conditions unlike larger nanocrystals, where Cu+ ions and vacancies form an ordered super-structure similar to the bulk solid. The clusters exhibit an unusual cationic sub-lattice arrangement wherein octahedral sites, which serve as bridges for cation migration, are stabilized by compressive strain. The room-temperature liquid-like nature of the Cu+ sub-lattice combined with the actively tunable plasmonic properties of the Cu2Se clusters make them suitable as fast electro-optic switches.

Characterization of bismuth selenide (Bi2Se3) thin films obtained by evaporating the hydrothermally synthesised nano-particles

NASA Astrophysics Data System (ADS)

Indirajith, R.; Rajalakshmi, M.; Gopalakrishnan, R.; Ramamurthi, K.

2016-03-01

Bismuth selenide (Bi2Se3) was synthesized by hydrothermal method at 200 °C and confirmed by powder X-ray diffraction (XRD) studies. The synthesized material was utilized to deposit bismuth selenide thin films at various substrate temperatures (Room Temperature-RT, 150 °C, 250 °C, 350 °C and 450 °C) by electron beam evaporation technique. XRD study confirmed the polycrystalline nature of the deposited Bi2Se3films. Optical transmittance spectra showed that the deposited (at RT) films acquire relatively high average transmittance of 60%in near infrared region (1500-2500 nm). An indirect allowed optical band gap calculated from the absorption edge for the deposited films is ranging from 0.62 to 0.8 eV. Scanning electron and atomic force microscopy analyses reveal the formation of nano-scale sized particles on the surface and that the nature of surface microstructures is influenced by the substrate temperature. Hall measurements showed improved electrical properties, for the films deposited at 350 °C which possess 2.8 times the mobility and 0.9 times the resistivity of the films deposited at RT.

Fluorescence imaging technology (FI) for high-throughput screening of selenide-modified nano-TiO2 catalysts.

PubMed

Wang, Liping; Lee, Jianchao; Zhang, Meijuan; Duan, Qiannan; Zhang, Jiarui; Qi, Hailang

2016-02-18

A high-throughput screening (HTS) method based on fluorescence imaging (FI) was implemented to evaluate the catalytic performance of selenide-modified nano-TiO2. Chemical ink-jet printing (IJP) technology was reformed to fabricate a catalyst library comprising 1405 (Ni(a)Cu(b)Cd(c)Ce(d)In(e)Y(f))Se(x)/TiO2 (M6Se/Ti) composite photocatalysts. Nineteen M6Se/Tis were screened out from the 1405 candidates efficiently.

Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model.

PubMed

Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming

2015-05-01

Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n = 12). Rabbits in the control group were injected with sterile saline (n = 12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4 hours after injection of technetium-99m-labeled annexin V (150 MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ± 0.29 in the early phase and 2.19 ± 0.34 in the delay phase, both of which were significantly higher than those of the control group (P = 0.03 and P = 0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.

Reactions of technetium hexafluoride with nitric acid, nitrosyl fluoride, and nitryl fluoride

NASA Technical Reports Server (NTRS)

Holloway, J. H.; Selig, H.

1970-01-01

Stoichiometry of technetium hexafluoride reactions is studied. Magnetic properties and infrared spectra of reaction products are studied and compared with those of analogous complexes of the hexafluorides of tungsten, rhenium, and osmium.

Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

ScienceCinema

Grover, Blaine

2018-05-01

Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

Tin sulfides and tin selenides at ambient and high pressure conditions

NASA Astrophysics Data System (ADS)

Nguyen Cong, Kien; Gonzalez, Joseph; Steele, Brad; Oleynik, Ivan

The application of high pressure promotes unusual chemical bonding in condensed phase resulting in the synthesis of novel materials, which may be recoverable in metastable states at ambient conditions. First-principles evolutionary crystal structure search is performed to explore novel tin sulfide (SnxSy) and tin selenide (SnxSy) crystals with the goal to discover novel photovoltaic and thermoelectric materials. Variable stoichiometry searches at various pressures are performed and the phase diagrams are constructed in the range of pressures 0-100 GPa, which include both the thermodynamically stable and lowest enthalpy metastable structures. Several new structures are identified and their dynamical stability is investigated. To help experimental synthesis of these novel compounds, Raman spectra and XRD patterns are also calculated. These new materials are also investigated to identify those with promising photovoltaic and thermoelectric properties.

Transglutaminase-mediated conjugation and nitride-technetium-99m labelling of a bis(thiosemicarbazone) bifunctional chelator.

PubMed

Salvarese, Nicola; Spolaore, Barbara; Marangoni, Selena; Pasin, Anna; Galenda, Alessandro; Tamburini, Sergio; Cicoria, Gianfranco; Refosco, Fiorenzo; Bolzati, Cristina

2018-06-01

An assessment study involving the use of the transglutaminase (TGase) conjugation method and the nitride-technetium-99m labelling on a bis(thiosemicarbazone) (BTS) bifunctional chelating agent is presented. The previously described chelator diacetyl-2-(N 4 -methyl-3-thiosemicarbazone)-3-(N 4 -amino-3-thiosemicarbazone), H 2 ATSM/A, has been functionalized with 6-aminohexanoic acid (ε-Ahx) to generate the bifunctional chelating agent diacetyl-2-(N 4 -methyl-3-thiosemicarbazone)-3-[N 4 -(amino)-(6-aminohexanoic acid)-3-thiosemicarbazone], H 2 ATSM/A-ε-Ahx (1), suitable for conjugation to glutamine (Gln) residues of bioactive molecules via TGase. The feasibility of the TGase reaction in the synthesis of a bioconjugate derivative was investigated using Substance P (SP) as model peptide. Compounds 1 and H 2 ATSM/A-ε-Ahx-SP (2) were labelled with nitride-technetium-99m, obtaining the complexes [ 99m Tc][Tc(N)(ATSM/A-ε-Ahx)] ( 99m Tc1) and [ 99m Tc][Tc(N)(ATSM/A-ε-Ahx-SP)] ( 99m Tc2). The chemical identity of 99m Tc1 and 99m Tc2 was confirmed by radio/UV-RP-HPLC combined with ESI-MS analysis on the respective carrier-added products 99g/99m Tc1 and 99g/99m Tc2. The stability of the radiolabelled complexes after incubation in various environments was investigated. All the results were compared with those obtained for the corresponding 64 Cu-analogues, 64 Cu1 and 64 Cu2. The TGase reaction allows the conjugation of 1 with the peptide, but it is not highly efficient due to instability of the chelator in the required conditions. The SP-conjugated complexes are unstable in mouse and human sera. However, indeed the BTS system can be exploited as nitride-technetium-99m chelator for highly efficient technetium labelling, thus making compound 1 worthy of further investigations for new targeted technetium and copper radiopharmaceuticals encompassing Single Photon Emission Computed Tomography and Positron Emission Tomography imaging. Copyright © 2018 Elsevier Inc. All rights

Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts

NASA Astrophysics Data System (ADS)

Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

2013-09-01

Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se

Interferences in electrochemical hydride generation of hydrogen selenide

NASA Astrophysics Data System (ADS)

Bolea, E.; Laborda, F.; Belarra, M. A.; Castillo, J. R.

2001-12-01

Interferences from Cu(II), Zn(II), Pt(IV), As(III) and nitrate on electrochemical hydride generation of hydrogen selenide were studied using a tubular flow-through generator, flow injection sample introduction and quartz tube atomic absorption spectrometry. Comparison with conventional chemical generation using tetrahydroborate was also performed. Lead and reticulated vitreous carbon (RVC), both in particulate form, were used as cathode materials. Signal supressions up to 60-75%, depending on the cathode material, were obtained in the presence of up to 200 mg l-1 of nitrate due to the competitive reduction of the anion. Interference from As(III) was similar in electrochemical and chemical generation, being related to the quartz tube atomization process. Zinc did not interfere up to Se/Zn ratios 1:100, whereas copper and platinum showed suppression levels up to 50% for Se/interferent ratios 1:100. Total signal suppression was observed in presence of Se/Cu ratios 1:100 when RVC cathodes were used. No memory effects were observed in any case. Scanning electron microscopy and squared wave voltametry studies supported the interference mechanism based on the decomposition of the hydride on the dispersed particles of the reduced metal.

Failure of technetium bone scanning to detect pseudarthroses in spinal fusion for scoliosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hannon, K.M.; Wetta, W.J.

1977-01-01

A prospective study of 11 patients suggests that present techniques of technetium bone scanning do not assist in recognizing the presence of well-established pseudarthrosis in spinal fusions for scoliosis.

Hyperthermia increases accumulation of technetium-99m-labeled liposomes in feline sarcomas.

PubMed

Matteucci, M L; Anyarambhatla, G; Rosner, G; Azuma, C; Fisher, P E; Dewhirst, M W; Needham, D; Thrall, D E

2000-09-01

The effect of hyperthermia on the accumulation of technetium-99m-labeled liposomes was studied in feline sarcomas. Each cat received two separate injections of liposomes. The first was used to quantify the amount of technetium-99m-labeled liposomes within the tumor under normothermic conditions. The second injection was made at the beginning of a 60-min hyperthermia procedure. Planar scintigraphy was used to measure the activity of technetium-99m-labeled liposomes within the tumor at predetermined times up to 18 h after injection. Regions of interest were drawn for the tumor, lungs, liver, kidney, and aorta. Counts in the regions of interest were decay corrected. Counts/pixel in the tumor under normothermic and hyperthermic conditions were normalized to aorta counts/pixel. A total of 16 cats were eligible for the study. In two of the 16 cats, incomplete count data precluded analysis. In the remaining 14 cats, hyperthermia resulted in a significant increase in liposome accumulation in the tumor (P = 0.001). Tumor volume ranged from 1.2 to 236.2 cm3, and thermal dose ranged from 2.0 to 243.3 CEM43CT90 (equivalent time that the 10th percentile temperature was equal to 43 degrees C). There was not a relationship between either tumor volume or hyperthermia dose on the magnitude of increased liposome accumulation, suggesting that this method has application across a range of tumor volumes and degrees of heatibility.

PREDICTION OF RELAPSE FROM HYPERTHYROIDISM FOLLOWING ANTITHYROID MEDICATION WITHDRAWAL USING TECHNETIUM THYROID UPTAKE SCANNING.

PubMed

Nakhjavani, Manouchehr; Abdollahi, Soraya; Farzanefar, Saeed; Abousaidi, Mohammadtagi; Esteghamati, Alireza; Naseri, Maryam; Eftekhari, Mohamad; Abbasi, Mehrshad

2017-04-02

Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement. Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic. Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3). TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal. ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

Water-stable fac-{TcO₃}⁺ complexes - a new field of technetium chemistry.

PubMed

Braband, Henrik

2011-01-01

The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.

Synthesis and characterization of (Ni{sub 1−x}Co{sub x})Se{sub 2} based ternary selenides as electrocatalyst for triiodide reduction in dye-sensitized solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Theerthagiri, J.; Senthil, R.A.; Buraidah, M.H.

2016-06-15

Ternary metal selenides of (Ni{sub 1−x}Co{sub x})Se{sub 2} with 0≤x≤1 were synthesized by using one-step hydrothermal reduction route. The synthesized metal selenides were utilized as an efficient, low-cost platinum free counter electrode for dye-sensitized solar cells. The cyclic voltammetry and electrochemical impedance spectroscopy studies revealed that the Ni{sub 0.5}Co{sub 0.5}Se{sub 2} counter electrode exhibited higher electrocatalytic activity and lower charge transfer resistance at the counter electrode/electrolyte interface than the other compositions for reduction of triiodide to iodide. Ternary selenides of Ni{sub 0.5}Co{sub 0.5}Se{sub 2} offer a synergistic effect to the electrocatalytic activity for the reduction of triiodide that might bemore » due to an increase in active catalytic sites and small charge transfer resistance. The DSSC with Ni{sub 0.5}Co{sub 0.5}Se{sub 2} counter electrode achieved a high power conversion efficiency of 6.02%, which is comparable with that of conventional platinum counter electrode (6.11%). This present investigation demonstrates the potential application of Ni{sub 0.5}Co{sub 0.5}Se{sub 2} as counter electrode in dye-sensitized solar cells.« less

Precipitation process for the removal of technetium values from nuclear waste solutions

DOEpatents

Walker, D.D.; Ebra, M.A.

1985-11-21

High efficiency removal of techetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

DOEpatents

Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; van Hest, Marinus Franciscus Antonius Maria; Ginley, David S [Evergreen, CO; Leisch, Jennifer [Denver, CO; Taylor, Matthew [West Simsbury, CT; Stanbery, Billy J [Austin, TX

2011-09-20

Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

Soft-tissue sarcoma: imaged with technetium-99m pyrophosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blatt, C.J.; Hayt, D.B.; Desai, M.

1977-11-01

A liposarcoma showed intense concentration of technetium-99m pyrophosphate. An angiogram demonstrated a highly vascular lesion, and it is suggested that blood flow played a major role in allowing the tumor to be demonstrated on scintiphotography. There was some histologic evidence of calcification which probably also contributed to bone-tracer disposition. Quantitative analysis of the specimen demonstrated that this calcification was located primarily in the areas of hemorrhage and necrosis.

Investigation of Second- and Third-Harmonic Generation in Few-Layer Gallium Selenide by Multiphoton Microscopy

PubMed Central

Karvonen, Lasse; Säynätjoki, Antti; Mehravar, Soroush; Rodriguez, Raul D.; Hartmann, Susanne; Zahn, Dietrich R. T.; Honkanen, Seppo; Norwood, Robert A.; Peyghambarian, N.; Kieu, Khanh; Lipsanen, Harri; Riikonen, Juha

2015-01-01

Gallium selenide (GaSe) is a layered semiconductor and a well-known nonlinear optical crystal. The discovery of graphene has created a new vast research field focusing on two-dimensional materials. We report on the nonlinear optical properties of few-layer GaSe using multiphoton microscopy. Both second- and third-harmonic generation from few-layer GaSe flakes were observed. Unexpectedly, even the peak at the wavelength of 390 nm, corresponding to the fourth-harmonic generation or the sum frequency generation from third-harmonic generation and pump light, was detected during the spectral measurements in thin GaSe flakes. PMID:25989113

Volatile species of technetium and rhenium during waste vitrification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dongsang; Kruger, Albert A.

Volatile loss of technetium (Tc) during vitrification of low-activity wastes is a technical challenge for treating and immobilizing the large volumes of radioactive and hazardous wastes stored at the U.S. Department of Energy's Hanford Site. There are various research efforts being pursued to develop technologies that can be implemented for cost effective management of Tc, including studies to understand the behavior of Tc during vitrification, with the goal of eventually increasing Tc retention in glass. Furthermore, one of these studies has focused on identifying the form or species of Tc and Re (surrogate for Tc) that evolve during the waste-to-glassmore » conversion process. This information is important for understanding the mechanism of Tc volatilization. In this paper, available information collected from the literature is critically evaluated to clarify the volatile species of Tc and Re and, more specifically, whether they volatilize as alkali pertechnetate and perrhenate or as technetium and rhenium oxides after decomposition of alkali pertechnetate and perrhenate. The evaluated data ranged from mass spectrometric identification of species volatilized from pure and binary alkali pertechnetate and perrhenate salts to structural and chemical analyses of volatilized materials during crucible melting and scaled melter processing of simulated wastes.« less

Volatile species of technetium and rhenium during waste vitrification

DOE PAGES

Kim, Dongsang; Kruger, Albert A.

2017-10-26

Volatile loss of technetium (Tc) during vitrification of low-activity wastes is a technical challenge for treating and immobilizing the large volumes of radioactive and hazardous wastes stored at the U.S. Department of Energy's Hanford Site. There are various research efforts being pursued to develop technologies that can be implemented for cost effective management of Tc, including studies to understand the behavior of Tc during vitrification, with the goal of eventually increasing Tc retention in glass. Furthermore, one of these studies has focused on identifying the form or species of Tc and Re (surrogate for Tc) that evolve during the waste-to-glassmore » conversion process. This information is important for understanding the mechanism of Tc volatilization. In this paper, available information collected from the literature is critically evaluated to clarify the volatile species of Tc and Re and, more specifically, whether they volatilize as alkali pertechnetate and perrhenate or as technetium and rhenium oxides after decomposition of alkali pertechnetate and perrhenate. The evaluated data ranged from mass spectrometric identification of species volatilized from pure and binary alkali pertechnetate and perrhenate salts to structural and chemical analyses of volatilized materials during crucible melting and scaled melter processing of simulated wastes.« less

Control of accidental releases of hydrogen selenide in vented storage cabinets

NASA Astrophysics Data System (ADS)

Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

1988-07-01

Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

Temperature induced phonon behaviour in germanium selenide thin films probed by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Taube, A.; Łapińska, A.; Judek, J.; Wochtman, N.; Zdrojek, M.

2016-08-01

Here we report a detailed study of temperature-dependent phonon properties of exfoliated germanium selenide thin films (several tens of nanometers thick) probed by Raman spectroscopy in the 70-350 K temperature range. The temperature-dependent behavior of the positions and widths of the Raman modes was nonlinear. We concluded that the observed effects arise from anharmonic phonon-phonon interactions and are explained by the phenomenon of optical phonon decay into acoustic phonons. At temperatures above 200 K, the position of the Raman modes tended to be linearly dependent, and the first order temperature coefficients χ were  -0.0277, -0.0197 and  -0.031 cm-1 K-1 for B 3g , A g(1) and A g(2) modes, respectively.

Technetium-99m NGA functional hepatic imaging: preliminary clinical experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.

1985-11-01

Technetium-99m galactosyl-neoglycoalbumin ( (Tc)NGA) is a radiolabeled ligand to hepatic binding protein, a receptor which resides at the plasma membrane of hepatocytes. This receptor-binding radiopharmaceutical and its kinetic model provide a noninvasive method for the assessment of liver function. Eighteen patients were studied: seven with hepatoma, eight with liver metastases, four with cirrhosis, and one patient with acute fulminant non-A, non-B hepatitis. Technetium-99m NGA liver imaging provided anatomic information of diagnostic quality comparable to that obtained with other routine imaging modalities, including computed tomography, angiography, ultrasound, and (Tc)sulfur colloid scintigraphy. Kinetic modeling of dynamic (Tc)NGA data produced estimates of standardizedmore » hepatic blood flow, Q (hepatic blood flow divided by total blood volume), and hepatic binding protein concentration, (HBP). Significant rank correlation was obtained between (HBP) estimates and CTC scores. This correlation supports the hypothesis that (HBP) is a measure of functional hepatocyte mass. The combination of decreased Q and markedly reduced (HBP) may have prognostic significance; all three patients with this combination died of hepatic failure within 6 wk of imaging.« less

Rhenium and technetium complexes that bind to amyloid-β plaques.

PubMed

Hayne, David J; North, Andrea J; Fodero-Tavoletti, Michelle; White, Jonathan M; Hung, Lin W; Rigopoulos, Angela; McLean, Catriona A; Adlard, Paul A; Ackermann, Uwe; Tochon-Danguy, Henri; Villemagne, Victor L; Barnham, Kevin J; Donnelly, Paul S

2015-03-21

Alzheimer's disease is associated with the presence of insoluble protein deposits in the brain called amyloid plaques. The major constituent of these deposits is aggregated amyloid-β peptide. Technetium-99m complexes that bind to amyloid-β plaques could provide important diagnostic information on amyloid-β plaque burden using Single Photon Emission Computed Tomography (SPECT). Tridentate ligands with a stilbene functional group were used to form complexes with the fac-[M(I)(CO)3](+) (M = Re or (99m)Tc) core. The rhenium carbonyl complexes with tridentate co-ligands that included a stilbene functional group and a dimethylamino substituent bound to amyloid-β present in human frontal cortex brain tissue from subjects with Alzheimer's disease. This chemistry was extended to make the analogous [(99m)Tc(I)(CO)3](+) complexes and the complexes were sufficiently stable in human serum. Whilst the lipophilicity (log D7.4) of the technetium complexes appeared ideally suited for penetration of the blood-brain barrier, preliminary biodistribution studies in an AD mouse model (APP/PS1) revealed relatively low brain uptake (0.24% ID g(-1) at 2 min post injection).

Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts.

PubMed

Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

2013-10-21

Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.

Power scaling of ultrafast laser inscribed waveguide lasers in chromium and iron doped zinc selenide.

PubMed

McDaniel, Sean A; Lancaster, Adam; Evans, Jonathan W; Kar, Ajoy K; Cook, Gary

2016-02-22

We report demonstration of Watt level waveguide lasers fabricated using Ultrafast Laser Inscription (ULI). The waveguides were fabricated in bulk chromium and iron doped zinc selenide crystals with a chirped pulse Yb fiber laser. The depressed cladding structure in Fe:ZnSe produced output powers of 1 W with a threshold of 50 mW and a slope efficiency of 58%, while a similar structure produced 5.1 W of output in Cr:ZnSe with a laser threshold of 350 mW and a slope efficiency of 41%. These results represent the current state-of-the-art for ULI waveguides in zinc based chalcogenides.

Organotin Selenide Clusters and Hybrid Capsules.

PubMed

Dehnen, Stefanie; Hanau, Katharina; Rinn, Niklas; Argentari, Mario

2018-05-22

Several compounds with unique structural motifs that have already been known from organotin sulfide chemistry, but remained unprecedented in organotin selenide chemistry so far, have been synthesized. The reaction of [(R1Sn)4Se6] (R1 = CMe2CH2C(O)Me) with N2H4·H2O/(SiMe3)2Se and with PhN2H3/(SiMe3)2Se led to the formation of [{(R2Sn)2SnSe4}2(µ-Se)2] (1) and [{(R3Sn)2SnSe4}2(µ-Se)2] (2) (R2 = CMe2CH2C(Me)NNH2, R3 = CMe2CH2C(Me)NNPhH), respectively. Addition of o-phthalaldehyde to [(R2Sn)4Se6] yielded a cluster with intramolecular bridging of the organic groups, [(R4Sn2)2Se6] (3, R4 = (CMe2CH2C(Me)NNCH)2C6H4). The introduction of organic ligands with longer chains finally allowed the isolation of inorganic-organic capsules of the type [(µ-R)3(Sn3Se4)2]X2, with R = (CMe2CH2C(Me)NNHC(O))2(CH2)4, X = [SnC3], Cl (4a, 4b) or R = CMe2CH2C(Me)NNH)2, X = [SnCl3] (5). The capsules enclose solvent molecules and/or anions as guests. All compounds were characterized via single-crystal X-ray diffraction, NMR spectroscopy and mass spectrometry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

DOEpatents

Krupke, W.F.; Page, R.H.; DeLoach, L.D.; Payne, S.A.

1996-07-30

A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr{sup 2+}-doped ZnS and ZnSe generate laser action near 2.3 {micro}m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d{sup 4} and d{sup 6} electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers. 18 figs.

Transition-metal doped sulfide, selenide, and telluride laser crystal and lasers

DOEpatents

Krupke, William F.; Page, Ralph H.; DeLoach, Laura D.; Payne, Stephen A.

1996-01-01

A new class of solid state laser crystals and lasers are formed of transition metal doped sulfide, selenide, and telluride host crystals which have four fold coordinated substitutional sites. The host crystals include II-VI compounds. The host crystal is doped with a transition metal laser ion, e.g., chromium, cobalt or iron. In particular, Cr.sup.2+ -doped ZnS and ZnSe generate laser action near 2.3 .mu.m. Oxide, chloride, fluoride, bromide and iodide crystals with similar structures can also be used. Important aspects of these laser materials are the tetrahedral site symmetry of the host crystal, low excited state absorption losses and high luminescence efficiency, and the d.sup.4 and d.sup.6 electronic configurations of the transition metal ions. The same materials are also useful as saturable absorbers for passive Q-switching applications. The laser materials can be used as gain media in amplifiers and oscillators; these gain media can be incorporated into waveguides and semiconductor lasers.

Evaluation of Hanford Tank Supernatant Availability for Technetium Management Project Studies in FY16

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapko, Brian M.

2015-09-30

This report examines the need for actual Hanford tank waste solutions to support tasks in the Technetium Management Program in fiscal year (FY) 2016. One key need is to identify both samples where a majority of the soluble technetium is present as pertechnetate and samples where it is not. The total amount of tank supernatant needed from any given tank waste supernatant was determined by polling the tasks leaders for their technology testing needs in FY16 and then arbitrarily ascribing a 10% process loss associated with consolidation and the Cs-137 removal needed to reduce the dose to a level suitablemore » for testing in radiological fumehoods. These polling results identified a need for approximately 2.1 to 3.6 kg of any particular targeted Hanford tank waste supernatant.« less

Determination of technetium-99 in environmental samples: a review.

PubMed

Shi, Keliang; Hou, Xiaolin; Roos, Per; Wu, Wangsuo

2012-01-04

Due to the lack of a stable technetium isotope, and the high mobility and long half-life, (99)Tc is considered to be one of the most important radionuclides in safety assessment of environmental radioactivity as well as nuclear waste management. (99)Tc is also an important tracer for oceanographic research due to the high technetium solubility in seawater as TcO(4)(-). A number of analytical methods, using chemical separation combined with radiometric and mass spectrometric measurement techniques, have been developed over the past decades for determination of (99)Tc in different environmental samples. This article summarizes and compares recently reported chemical separation procedures and measurement methods for determination of (99)Tc. Due to the extremely low concentration of (99)Tc in environmental samples, the sample preparation, pre-concentration, chemical separation and purification for removal of the interferences for detection of (99)Tc are the most important issues governing the accurate determination of (99)Tc. These aspects are discussed in detail in this article. Meanwhile, the different measurement techniques for (99)Tc are also compared with respect to advantages and drawbacks. Novel automated analytical methods for rapid determination of (99)Tc using solid extraction or ion exchange chromatography for separation of (99)Tc, employing flow injection or sequential injection approaches are also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

The growth of zinc selenide single crystals by physical vapor transport in microgravity

NASA Technical Reports Server (NTRS)

Anderson, Elmer E.; Rosenberger, Franz E.; Cheng, Hai-Yuin

1990-01-01

Growth and characterization studies will be performed on zinc selenide single crystals. The high temperature outgassing behavior of the silica ampoule material will be studied in order to develop a cleaning and bake-out procedure that will minimize the amount of impurities introduced into the vapor from the ampoule materials and in particular during the seal-off procedure. The outgassing behavior of the ZnSe starting material will be studied during high vacuum refinement at elevated temperatures in order to develop a temperature pressure program that will optimize the removal of impurities while minimizing a shift in stoichiometry due to preferred evaporation of the higher fugacity component. The mass spectrometer system was completed, and after calibration, will be used to perform the above tasks. The system and its operation is described in detail.

Transition-Metal-Free Diarylannulated Sulfide and Selenide Construction via Radical/Anion-Mediated Sulfur-Iodine and Selenium-Iodine Exchange.

PubMed

Wang, Ming; Fan, Qiaoling; Jiang, Xuefeng

2016-11-04

A facile, straightforward protocol was established for diarylannulated sulfide and selenide construction through S-I and Se-I exchange without transition metal assistance. Elemental sulfur and selenium served as the chalcogen source. Diarylannulated sulfides were systematically achieved from a five- to eight-membered ring. A trisulfur radical anion was demonstrated as the initiator for this radical process via electron paramagnetic resonance (EPR) study. OFET molecules [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and [1]benzothieno[3,2-b][1]benzoselenophene (BTBS) were efficiently established.

Ternary lanthanum sulfide selenides {alpha}-LaS{sub 2-x}Se{sub x} (0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bartsch, Christian; Doert, Thomas, E-mail: thomas.doert@chemie.tu-dresden.de

2012-01-15

Mixed lanthanum sulfide selenides LaS{sub 2-x}Se{sub x} (0selenides. Highlights: Black-Right-Pointing-Pointer Vegard series of mixed lanthanum sulfide selenides LaS{sub 2-x}Se{sub x} (0

Solar Light Responsive Photocatalytic Activity of Reduced Graphene Oxide-Zinc Selenide Nanocomposite

NASA Astrophysics Data System (ADS)

Chakraborty, Koushik; Ibrahim, Sk; Das, Poulomi; Ghosh, Surajit; Pal, Tanusri

2017-10-01

Solution processable reduced graphene oxide-zinc selenide (RGO-ZnSe) nanocomposite has been successfully synthesized by an easy one-pot single-step solvothermal reaction. The RGO-ZnSe composite was characterized structurally and morphologically by the study of XRD analysis, SEM and TEM imaging. Reduction in graphene oxide was confirmed by FTIR spectroscopy analysis. Photocatalytic efficiency of RGO-ZnSe composite was investigated toward the degradation of Rhodamine B under solar light irradiation. Our study indicates that the RGO-ZnSe composite is catalytically more active compared to the controlled-ZnSe under the solar light illumination. Here, RGO plays an important role for photoinduced charge separation and subsequently hinders the electron-hole recombination probability that consequently enhances photocatalytic degradation efficiency. We expect that this type of RGO-based optoelectronics materials opens up a new avenue in the field of photocatalytic degradation of different organic water pollutants.

Phonon-driven electron scattering and magnetothermoelectric effect in two-dimensional tin selenide

NASA Astrophysics Data System (ADS)

Yang, Kaike; Ren, Ji-Chang; Qiu, Hongfei; Wang, Jian-Sheng

2018-02-01

The bulk tin selenide (SnSe) is the best thermoelectric material currently with the highest figure-of-merit due to strong phonon-phonon interactions. We investigate the effect of electron-phonon coupling (EPC) on the transport properties of a two-dimensional (2D) SnSe sheet. We demonstrate that EPC plays a key role in the scattering rate when the constant relaxation time approximation is deficient. The EPC strength is especially large in contrast to that of pristine graphene. The scattering rate depends sensitively on the system temperatures and the carrier densities when the Fermi energy approaches the band edge. We also investigate the magnetothermoelectric effect of the 2D SnSe. It is found that at low temperatures there is enormous magnetoelectrical resistivity and magnetothermal resistivity above 200%, suggesting possible potential applications in device design. Our results agree qualitatively well with the experimental data.

Discovery of rhenium and masurium (technetium) by Ida Noddack-Tacke and Walter Noddack. Forgotten heroes of nuclear medicine.

PubMed

Biersack, H-J; Stelzner, F; Knapp, F F

2015-01-01

The history of the early identification of elements and their designation to the Mendeleev Table of the Elements was an important chapter in German science in which Ida (1896-1978) and Walter (1893-1960) Noddack played an important role in the first identification of rhenium (element 75, 1925) and technetium (element 43, 1933). In 1934 Ida Noddack was also the first to predict fission of uranium into smaller atoms. Although the Noddacks did not for some time later receive the recognition for the first identification of technetium-99m, their efforts have appropriately more recently been recognized. The discoveries of these early pioneers are even more astounding in light of the limited technologies and resources which were available during this period. The Noddack discoveries of elements 43 and 75 are related to the subsequent use of rhenium-188 (beta/gamma emitter) and technetium-99m (gamma emitter) in nuclear medicine. In particular, the theranostic relationship between these two generator-derived radioisotopes has been demonstrated and offers new opportunities in the current era of personalized medicine.

Candidate Low-Temperature Glass Waste Forms for Technetium-99 Recovered from Hanford Effluent Management Facility Evaporator Concentrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Mei; Tang, Ming; Rim, Jung Ho

Alternative treatment and disposition options may exist for technetium-99 (99Tc) in secondary liquid waste from the Hanford Direct-Feed Low-Activity Waste (DFLAW) process. One approach includes development of an alternate glass waste form that is suitable for on-site disposition of technetium, including salts and other species recovered by ion exchange or precipitation from the EMF evaporator concentrate. By recovering the Tc content from the stream, and not recycling the treated concentrate, the DFLAW process can potentially be operated in a more efficient manner that lowers the cost to the Department of Energy. This report provides a survey of candidate glass formulationsmore » and glass-making processes that can potentially incorporate technetium at temperatures <700 °C to avoid volatilization. Three candidate technetium feed streams are considered: (1) dilute sodium pertechnetate loaded on a non-elutable ion exchange resin; (2) dilute sodium-bearing aqueous eluent from ion exchange recovery of pertechnetate, or (3) technetium(IV) oxide precipitate containing Sn and Cr solids in an aqueous slurry. From the technical literature, promising candidate glasses are identified based on their processing temperatures and chemical durability data. The suitability and technical risk of three low-temperature glass processing routes (vitrification, encapsulation by sintering into a glass composite material, and sol-gel chemical condensation) for the three waste streams was assessed, based on available low-temperature glass data. For a subset of candidate glasses, their long-term thermodynamic behavior with exposure to water and oxygen was modeled using Geochemist’s Workbench, with and without addition of reducing stannous ion. For further evaluation and development, encapsulation of precipitated TcO2/Sn/Cr in a glass composite material based on lead-free sealing glasses is recommended as a high priority. Vitrification of pertechnetate in aqueous anion exchange eluent

Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

PubMed

Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

2015-01-14

Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ∼127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known √5×√5 iron vacancy ordered state, resulting in an AFM order at ∼500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors.

Sensitivity of technetium-99m-pyrophosphate scintigraphy in diagnosing cardiac amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falk, R.H.; Lee, V.W.; Rubinow, A.

1983-03-01

To determine the value of technetium-99m-pyrophosphate myocardial scintigraphy in the diagnosis of amyloid heart disease this procedure was prospectively performed in 20 consecutive patients with biopsy-proven primary amyloidosis. Eleven patients had echocardiographic abnormalities compatible with amyloid cardiomyopathy, 9 of whom had congestive heart failure. Diffuse myocardial pyrophosphate uptake was of equal or greater intensity than that of the ribs in 9 of the 11 patients with echocardiograms suggestive of amyloidosis, but in only 2 of the 9 with normal echocardiograms, despite abnormal electrocardiograms (p less than 0.01). Increased wall thickness measured by M-mode echocardiography correlated with myocardial pyrophosphate uptake (rmore » . 0.68, p less than 0.01). None of 10 control patients with nonamyloid, nonischemic heart disease had a strongly positive myocardial pyrophosphate uptake. Thus, myocardial technetium-99m-pyrophosphate scanning is a sensitive and specific test for the diagnosis of cardiac amyloidosis in patients with congestive heart failure of obscure origin. It does not appear to be of value for the early detection of cardiac involvement in patients with known primary amyloidosis without echocardiographic abnormalities.« less

The corrosion behavior of technetium metal exposed to aqueous sulfate and chloride solutions

DOE PAGES

Kolman, David Gary; Goff, George Scott; Cisneros, Michael Ruben; ...

2017-04-19

Here, metal waste forms are being studied as possible disposal forms for technetium and other fission products from spent nuclear fuel. As an initial step in assessing the viability of waste forms, technetium corrosion and passivity behavior was assessed across a broad pH spectrum (pH –1 to pH 13). Measurements indicate that the open circuit potential falls into the region of Tc +7 stability, more noble than the region of presumed passivity. Potentiodynamic polarization tests indicate that the Tc samples are not passive. Both electrochemical results and visual inspection suggest the presence of a nonprotective film. The corrosion rate ismore » relatively independent of pH and low, as measured by linear polarization resistance. No evidence of passivity was observed in the Tc +4 region of the potential-pH diagram following in-situ abrasion, suggesting that Tc does not passivate, regardless of potential.« less

The corrosion behavior of technetium metal exposed to aqueous sulfate and chloride solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolman, David Gary; Goff, George Scott; Cisneros, Michael Ruben

Here, metal waste forms are being studied as possible disposal forms for technetium and other fission products from spent nuclear fuel. As an initial step in assessing the viability of waste forms, technetium corrosion and passivity behavior was assessed across a broad pH spectrum (pH –1 to pH 13). Measurements indicate that the open circuit potential falls into the region of Tc +7 stability, more noble than the region of presumed passivity. Potentiodynamic polarization tests indicate that the Tc samples are not passive. Both electrochemical results and visual inspection suggest the presence of a nonprotective film. The corrosion rate ismore » relatively independent of pH and low, as measured by linear polarization resistance. No evidence of passivity was observed in the Tc +4 region of the potential-pH diagram following in-situ abrasion, suggesting that Tc does not passivate, regardless of potential.« less

Thermoelectric characterization of individual bismuth selenide topological insulator nanoribbons.

PubMed

Tang, Hao; Wang, Xiaomeng; Xiong, Yucheng; Zhao, Yang; Zhang, Yin; Zhang, Yan; Yang, Juekuan; Xu, Dongyan

2015-04-21

Bismuth selenide (Bi2Se3) nanoribbons have attracted tremendous research interest recently to study the properties of topologically protected surface states that enable new opportunities to enhance the thermoelectric performance. However, the thermoelectric characterization of individual Bi2Se3 nanoribbons is rare due to the technological challenges in the measurements. One challenge is to ensure good contacts between the nanoribbon and electrodes in order to determine the thermal and electrical properties accurately. In this work, we report the thermoelectric characterization of individual Bi2Se3 nanoribbons via a suspended microdevice method. Through careful measurements, we have demonstrated that contact thermal resistance is negligible after the electron-beam-induced deposition (EBID) of platinum/carbon (Pt/C) composites at the contacts between the nanoribbon and electrodes. It is shown that the thermal conductivity of the Bi2Se3 nanoribbons is less than 50% of the bulk value over the whole measurement temperature range, which can be attributed to enhanced phonon boundary scattering. Our results indicate that intrinsic Bi2Se3 nanoribbons prepared in this work are highly doped n-type semiconductors, and therefore the Fermi level should be in the conduction band and no topological transport behavior can be observed in the intrinsic system.

Separation of uranium from technetium in recovery of spent nuclear fuel

DOEpatents

Pruett, D.J.; McTaggart, D.R.

1983-08-31

Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc/sup +7/ therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.

Separation of uranium from technetium in recovery of spent nuclear fuel

DOEpatents

Pruett, David J.; McTaggart, Donald R.

1984-01-01

Uranium and technetium in the product stream of the Purex process for recovery of uranium in spent nuclear fuel are separated by (1) contacting the aqueous Purex product stream with hydrazine to reduce Tc.sup.+7 therein to a reduced species, and (2) contacting said aqueous stream with an organic phase containing tributyl phosphate and an organic diluent to extract uranium from said aqueous stream into said organic phase.

Transport properties of Cu-doped bismuth selenide single crystals at high magnetic fields up to 60 Tesla: Shubnikov-de Haas oscillations and π-Berry phase

NASA Astrophysics Data System (ADS)

Romanova, Taisiia A.; Knyazev, Dmitry A.; Wang, Zhaosheng; Sadakov, Andrey V.; Prudkoglyad, Valery A.

2018-05-01

We report Shubnikov-de Haas (SdH) and Hall oscillations in Cu-doped high quality bismuth selenide single crystals. To increase the accuracy of Berry phase determination by means of the of the SdH oscillations phase analysis we present a study of n-type samples with bulk carrier density n ∼1019 -1020cm-3 at high magnetic field up to 60 Tesla. In particular, Landau level fan diagram starting from the value of the Landau index N = 4 was plotted. Thus, from our data we found π-Berry phase that directly indicates the Dirac nature of the carriers in three-dimensional topological insulator (3D TI) based on Cu-doped bismuth selenide. We argued that in our samples the magnetotransport is determined by a general group of carriers that exhibit quasi-two-dimensional (2D) behaviour and are characterized by topological π-Berry phase. Along with the main contribution to the conductivity the presence of a small group of bulk carriers was registered. For 3D-pocket Berry phase was identified as zero, which is a characteristic of trivial metallic states.

Identification of neutron deficient niobium, molybdenum and technetium isotopes

NASA Astrophysics Data System (ADS)

Gross, C. J.

We report on the in-beam identification of fourteen new isotopes in the A=80-90 region. Heavy-ion reactions with a recoil separator or charged particle and neutron detectors provided identification of γ-rays from these new niobium, molybdenum, and technetium isotopes. The procedures used are described and energy level systematics are discussed. The energy levels appear to be organized into rotational bands in nuclei with N≤44 while those with N ≥ 46 have more single-particle-like transitions. Lifetime measurements in 87Mo and 87Nb indicate that g {9}/{2} particle alignment strongly influences the collectivity of these nuclei.

Optoelectronic and low temperature thermoelectric studies on nanostructured thin films of silver gallium selenide

NASA Astrophysics Data System (ADS)

Jacob, Rajani; Philip, Rachel Reena; Nazer, Sheeba; Abraham, Anitha; Nair, Sinitha B.; Pradeep, B.; Urmila, K. S.; Okram, G. S.

2014-01-01

Polycrystalline thin films of silver gallium selenide were deposited on ultrasonically cleaned soda lime glass substrates by multi-source vacuum co-evaporation technique. The structural analysis done by X-ray diffraction ascertained the formation of nano structured tetragonal chalcopyrite thin films. The compound formation was confirmed by X-ray photo-electron spectroscopy. Atomic force microscopic technique has been used for surface morphological analysis. Direct allowed band gap ˜1.78eV with high absorption coefficient ˜106/m was estimated from absorbance spectra. Low temperature thermoelectric effects has been investigated in the temperature range 80-330K which manifested an unusual increase in Seebeck coefficient with negligible phonon drag toward the very low and room temperature regime. The electrical resistivity of these n-type films was assessed to be ˜2.6Ωm and the films showed good photo response.

Increased technetium uptake is not equivalent to muscle necrosis: scintigraphic, morphological and intramuscular pressure analyses of sore muscles after exercise

NASA Technical Reports Server (NTRS)

Crenshaw, A. G.; Friden, J.; Hargens, A. R.; Lang, G. H.; Thornell, L. E.

1993-01-01

A scintigraphic technique employing technetium pyrophosphate uptake was used to identify the area of skeletal muscle damage in the lower leg of four runners 24 h after an ultramarathon footrace (160 km). Most of the race had been run downhill which incorporated an extensive amount of eccentric work. Soreness was diffuse throughout the posterior region of the lower leg. In order to interpret what increased technetium uptake reflects and to express extreme endurance related damages, a biopsy was taken from the 3-D position of abnormal uptake. In addition, intramuscular pressures were determined in the deep posterior compartment. Scintigraphs revealed increased technetium pyrophosphate uptake in the medial portion of the gastrocnemius muscle. For 3698 fibres analysed, 33 fibres (1%) were necrotic, while a few other fibres were either atrophic or irregular shaped. A cluster of necrotic fibres occurred at the fascicular periphery for one subject and fibre type grouping occurred for another. Ultrastructural analysis revealed Z-line streaming near many capillaries and variously altered subsarcolemmal mitochondria including some with paracrystalline inclusions. The majority of the capillaries included thickened and irregular shaped endothelial cells. Intramuscular pressures of the deep posterior compartment were slightly elevated (12-15 mmHg) for three of the four subjects. Increased technetium uptake following extreme endurance running does not just reflect muscle necrosis but also subtle fibre abnormalities. Collectively, these pathological findings are attributed to relative ischaemia occurring during the race and during pre-race training, whereas, intramuscular pressure elevations associated with muscle soreness are attributed to mechanical stress caused by extensive eccentric work during the race.

Transparent nickel selenide alloy counter electrodes for bifacial dye-sensitized solar cells exceeding 10% efficiency.

PubMed

Duan, Yanyan; Tang, Qunwei; He, Benlin; Li, Ru; Yu, Liangmin

2014-11-07

In the current work, we report a series of bifacial dye-sensitized solar cells (DSSCs) that provide power conversion efficiencies of more than 10% from bifacial irradiation. The device comprises an N719-sensitized TiO2 anode, a transparent nickel selenide (Ni-Se) alloy counter electrode (CE), and liquid electrolyte containing I(-)/I3(-) redox couples. Because of the high optical transparency, electron conduction ability, electrocatalytic activity of Ni-Se CEs, as well as dye illumination, electron excitation and power conversion efficiency have been remarkably enhanced. Results indicate that incident light from a transparent CE has a compensation effect to the light from the anode. The impressive efficiency along with simple preparation of the cost-effective Ni-Se alloy CEs highlights the potential application of bifacial illumination technique in robust DSSCs.

Solid-Solution Anion-Enhanced Electrochemical Performances of Metal Sulfides/Selenides for Sodium-Ion Capacitors: The Case of FeS2- xSe x.

PubMed

Long, Yaqiong; Yang, Jing; Gao, Xin; Xu, Xuena; Fan, Weiliu; Yang, Jian; Hou, Shifeng; Qian, Yitai

2018-04-04

Transition-metal sulfides/selenides are explored as advanced electrode materials for nonaqueous sodium-ion capacitors, using FeS 2- x Se x as an example. A solid solution of S/Se in FeS 2- x Se x allows it to combine the high capacity of FeS 2 and the good diffusion kinetics of FeSe 2 together, thereby exhibiting excellent cycle stability (∼220 mA h g -1 after 6000 cycles at 2 A g -1 ) and superior rate capability (∼210 mA h g -1 at 40 A g -1 ) within 0.8-3.0 V. These results are much better than those of FeS 2 and FeSe 2 , confirming the advantages of S/Se solid solution, as supported by EIS spectra, DFT calculations, and electronic conductivity. As FeS 2- x Se x is paired with the activated carbon (AC) as Na-ion capacitors, this device is also better than sodium-ion batteries of FeS 2- x Se x //Na 3 V 2 (PO 4 ) 3 and sodium-ion capacitors of metal oxides//AC, particularly at high rates. These results open a new door for the applications of sulfides/selenides in another device of electrochemical energy storage.

Synthesis and Characterization of Aqueous Lead Selenide Quantum Dots for Solar Cell Application

NASA Astrophysics Data System (ADS)

Albert, Ancy; Sreekala, C. O.; Prabhakaran, Malini

2018-02-01

High quality, colloidal lead selenide (PbSe) nanoparticles possessing cube shaped morphology have been successfully synthesized by organometallic synthesis method, using oleic acid (OA) as capping agent. The use of non-coordinating solvent, 1-Octadecene (ODE), during the synthesis results in good quality nanocrystals. Morphology analysis by transmission electron microscopy reveals that cube-shaped nanocrystals with a size range of 10 nm have been produced during the synthesis. The absorption and PL spectra analysis showed an emission peak at 675 nm when excited to a wavelength of 610 nm, further confirmed the formation of PbSe nanocrystals. The surface modification of this colloidal quantum dots was then carried out using L- cysteine ligand, to make them water soluble, for solar cell application. The J-V characteristics study of this PbSe quantum dots solar cell (PbSe QDSC) showed a little power conversion efficiency which intern it shows significant advance toward effective utilization of PbSe nanocrystals sensitized in solar cells.

Point contacts at the copper-indium-gallium-selenide interface—A theoretical outlook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bercegol, Adrien, E-mail: adrien.bercegol@polytechnique.edu; Chacko, Binoy; Klenk, Reiner

For a long time, it has been assumed that recombination in the space-charge region of copper-indium-gallium-selenide (CIGS) is dominant, at least in high efficiency solar cells with low band gap. The recent developments like potassium fluoride post deposition treatment and point-contact junction may call this into question. In this work, a theoretical outlook is made using three-dimensional simulations to investigate the effect of point-contact openings through a passivation layer on CIGS solar cell performance. A large set of solar cells is modeled under different scenarios for the charged defect levels and density, radius of the openings, interface quality, and conductionmore » band offset. The positive surface charge created by the passivation layer induces band bending and this influences the contact (CdS) properties, making it beneficial for the open circuit voltage and efficiency, and the effect is even more pronounced when coverage area is more than 95%, and also makes a positive impact on the device performance, even in the presence of a spike at CIGS/CdS heterojunction.« less

Effect of cadmium-selenide quantum dots on the conductivity and photoconductivity of nanocrystalline indium oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Il’in, A. S., E-mail: as.ilin@physics.msu.ru; Fantina, N. P.; Martyshov, M. N.

The effect of cadmium-selenide quantum dots addition on the electrical and photoelectric properties of nanocrystalline indium oxide with nanocrystal dimensions in the range from 7 to 40 nm is studied. By impedance spectroscopy, it is shown that the addition of quantum dots substantially influences the resistance of interfaces between In{sub 2}O{sub 3} crystals. A change in the character of the photoconductivity spectrum of In{sub 2}O{sub 3} upon the addition of CdSe quantum dots is detected, and it is established that this change depends on the In{sub 2}O{sub 3}-nanocrystal dimensions. An energy band diagram is proposed to explain the observed changemore » in the photoconductivity spectrum of In{sub 2}O{sub 3} upon the addition of CdSe quantum dots.« less

Separation of uranium from technetium in recovery of spent nuclear fuel

NASA Astrophysics Data System (ADS)

Friedman, H. A.

1984-06-01

A method for decontaminating uranium product from the Purex 5 process is described. Hydrazine is added to the product uranyl nitrate stream from the Purex process, which contains hexavalent (UO2(2+)) uranium and heptavalent technetius (TcO4-). Technetium in the product stream is reduced and then complexed by the addition of oxalic acid (H2O2O4), and the Tc-oxalate complex is readily separated from the 10 uranium by solvent extraction with 30 vol % tributyl phosphate in n-dodecane.

Evaluation of Technetium Getters to Improve the Performance of Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeway, James J.; Qafoku, Nikolla P.; Serne, R. Jeffrey

2015-11-01

Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. One of the major radionuclides that Cast Stone has the potential to immobilize is technetium (Tc). The mechanism for immobilization is through the reduction of the highly mobile Tc(VII)more » species to the less mobile Tc(IV) species by the blast furnace slag (BFS) used in the Cast Stone formulation. Technetium immobilization through this method would be beneficial because Tc is one of the most difficult contaminants to address at the U.S. Department of Energy (DOE) Hanford Site due to its complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes (vitrification, steam reformation, etc.), and high mobility in subsurface environments. In fact, the Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington (TC&WM EIS) identifies technetium-99 ( 99Tc) as one of the radioactive tank waste components contributing the most to the environmental impact associated with the cleanup of the Hanford Site. The TC&WM EIS, along with an earlier supplemental waste-form risk assessment, used a diffusion-limited release model to estimate the release of different contaminants from the WTP process waste forms. In both of these predictive modeling exercises, where effective diffusivities based on grout performance data available at the time, groundwater at the 100-m down-gradient well exceeded the allowable maximum permissible concentrations for 99Tc. (900 pCi/L). Recent relatively short-term (63

Advances and Challenges in Metal Sulfides/Selenides for Next-Generation Rechargeable Sodium-Ion Batteries.

PubMed

Hu, Zhe; Liu, Qiannan; Chou, Shu-Lei; Dou, Shi-Xue

2017-12-01

Rechargeable sodium-ion batteries (SIBs), as the most promising alternative to commercial lithium-ion batteries, have received tremendous attention during the last decade. Among all the anode materials for SIBs, metal sulfides/selenides (MXs) have shown inspiring results because of their versatile material species and high theoretical capacity. They suffer from large volume expansion, however, which leads to bad cycling performance. Thus, methods such as carbon modification, nanosize design, electrolyte optimization, and cut-off voltage control are used to obtain enhanced performance. Here, recent progress on MXs is summarized in terms of arranging the crystal structure, synthesis methods, electrochemical performance, mechanisms, and kinetics. Challenges are presented and effective ways to solve the problems are proposed, and a perspective for future material design is also given. It is hoped that light is shed on the development of MXs to help finally find applications for next-generation rechargeable batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals.

PubMed

Li, Xufan; Basile, Leonardo; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A; Lee, Jaekwang; Idrobo, Juan C; Chi, Miaofang; Rouleau, Christopher M; Geohegan, David B; Xiao, Kai

2015-02-23

Characterizing and controlling the interlayer orientations and stacking orders of two-dimensional (2D) bilayer crystals and van der Waals (vdW) heterostructures is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) crystals that result from different layer stackings provide an ideal platform to study the stacking configurations in 2D bilayer crystals. Through a controllable vapor-phase deposition method, bilayer GaSe crystals were selectively grown and their two preferred 0° or 60° interlayer rotations were investigated. The commensurate stacking configurations (AA' and AB stacking) in as-grown bilayer GaSe crystals are clearly observed at the atomic scale, and the Ga-terminated edge structure was identified using scanning transmission electron microscopy. Theoretical analysis reveals that the energies of the interlayer coupling are responsible for the preferred orientations among the bilayer GaSe crystals. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Field Effect Transistors Using Atomically Thin Layers of Copper Indium Selenide (CuInSe)

NASA Astrophysics Data System (ADS)

Patil, Prasanna; Ghosh, Sujoy; Wasala, Milinda; Lei, Sidong; Vajtai, Robert; Ajayan, Pulickel; Talapatra, Saikat

We will report fabrication of field-effect transistors (FETs) using few-layers of Copper Indium Selenide (CuInSe) flakes exfoliated from crystals grown using chemical vapor transport technique. Our transport measurements indicate n-type FET with electron mobility µ ~ 3 cm2 V-1 s-1 at room temperature when Silicon dioxide (SiO2) is used as a back gate. Mobility can be further increased significantly when ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6) is used as top gate. Similarly subthreshold swing can be further improved from 103 V/dec to 0.55 V/dec by using ionic liquid as a top gate. We also found ON/OFF ratio of ~ 102 for both top and back gate. Comparison between ionic liquid top gate and SiO2 back gate will be presented and discussed. This work is supported by the U.S. Army Research Office through a MURI Grant # W911NF-11-1-0362.

Topological insulator bismuth selenide as a theranostic platform for simultaneous cancer imaging and therapy.

PubMed

Li, Juan; Jiang, Fei; Yang, Bo; Song, Xiao-Rong; Liu, Yan; Yang, Huang-Hao; Cao, Dai-Rong; Shi, Wen-Rong; Chen, Guo-Nan

2013-01-01

Employing theranostic nanoparticles, which combine both therapeutic and diagnostic capabilities in one dose, has promise to propel the biomedical field toward personalized medicine. Here we investigate the theranostic properties of topological insulator bismuth selenide (Bi2Se3) in in vivo and in vitro system for the first time. We show that Bi2Se3 nanoplates can absorb near-infrared (NIR) laser light and effectively convert laser energy into heat. Such photothermal conversion property may be due to the unique physical properties of topological insulators. Furthermore, localized and irreversible photothermal ablation of tumors in the mouse model is successfully achieved by using Bi2Se3 nanoplates and NIR laser irradiation. In addition, we also demonstrate that Bi2Se3 nanoplates exhibit strong X-ray attenuation and can be utilized for enhanced X-ray computed tomography imaging of tumor tissue in vivo. This study highlights Bi2Se3 nanoplates could serve as a promising platform for cancer diagnosis and therapy.

Design, Synthesis, and X-ray of Selenides as New Class of Agents for Prevention of Diabetic Cerebrovascular Pathology.

PubMed

Angeli, Andrea; di Cesare Mannelli, Lorenzo; Trallori, Elena; Peat, Thomas S; Ghelardini, Carla; Carta, Fabrizio; Supuran, Claudiu T

2018-05-10

A series of novel selenides bearing benzenesulfonamide moieties was synthesized and investigated for their inhibition on six human (h) carbonic anhydrase (CA, EC 4.2.1.1) isoforms such as the physiologically relevant hCA I, II, VA, VB, VII, and IX and the X-ray complex in adduct with hCA II for some of them investigated. These enzymes are involved in a variety of diseases including glaucoma, retinitis pigmentosa, epilepsy, arthritis, metabolic disorders, and cancer. The investigated compounds showed potent inhibitory action against hCA VA, VII, and IX, in the low nanomolar range, thus making them of interest for the development of isoform-selective inhibitors and as candidates for various biomedical applications.

Toward hypoxia-selective rhenium and technetium tricarbonyl complexes.

PubMed

North, Andrea J; Hayne, David J; Schieber, Christine; Price, Katherine; White, Anthony R; Crouch, Peter J; Rigopoulos, Angela; O'Keefe, Graeme J; Tochon-Danguy, Henri; Scott, Andrew M; White, Jonathan M; Ackermann, Uwe; Donnelly, Paul S

2015-10-05

With the aim of preparing hypoxia-selective imaging and therapeutic agents, technetium(I) and rhenium(I) tricarbonyl complexes with pyridylhydrazone, dipyridylamine, and pyridylaminocarboxylate ligands containing nitrobenzyl or nitroimidazole functional groups have been prepared. The rhenium tricarbonyl complexes were synthesized with short reaction times using microwave irradiation. Rhenium tricarbonyl complexes with deprotonated p-nitrophenyl pyridylhydrazone ligands are luminescent, and this has been used to track their uptake in HeLa cells using confocal fluorescent microscopy. Selected rhenium tricarbonyl complexes displayed higher uptake in hypoxic cells when compared to normoxic cells. A (99m)Tc tricarbonyl complex with a dipyridylamine ligand bearing a nitroimidazole functional group is stable in human serum and was shown to localize in a human renal cell carcinoma (RCC; SK-RC-52) tumor in a mouse.

Growth of zinc selenide single crystals by physical vapor transport in microgravity

NASA Technical Reports Server (NTRS)

Rosenberger, Franz

1993-01-01

The goals of this research were the optimization of growth parameters for large (20 mm diameter and length) zinc selenide single crystals with low structural defect density, and the development of a 3-D numerical model for the transport rates to be expected in physical vapor transport under a given set of thermal and geometrical boundary conditions, in order to provide guidance for an advantageous conduct of the growth experiments. In the crystal growth studies, it was decided to exclusively apply the Effusive Ampoule PVT technique (EAPVT) to the growth of ZnSe. In this technique, the accumulation of transport-limiting gaseous components at the growing crystal is suppressed by continuous effusion to vacuum of part of the vapor contents. This is achieved through calibrated leaks in one of the ground joints of the ampoule. Regarding the PVT transport rates, a 3-D spectral code was modified. After introduction of the proper boundary conditions and subroutines for the composition-dependent transport properties, the code reproduced the experimentally determined transport rates for the two cases with strongest convective flux contributions to within the experimental and numerical error.

Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide.

PubMed

Zeljkovic, Ilija; Scipioni, Kane L; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.

Photoconductivity in reactively evaporated copper indium selenide thin films

NASA Astrophysics Data System (ADS)

Urmila, K. S.; Asokan, T. Namitha; Pradeep, B.; Jacob, Rajani; Philip, Rachel Reena

2014-01-01

Copper indium selenide thin films of composition CuInSe2 with thickness of the order of 130 nm are deposited on glass substrate at a temperature of 423 ±5 K and pressure of 10-5 mbar using reactive evaporation, a variant of Gunther's three temperature method with high purity Copper (99.999%), Indium (99.999%) and Selenium (99.99%) as the elemental starting materials. X-ray diffraction (XRD) studies shows that the films are polycrystalline in nature having preferred orientation of grains along the (112) plane. The structural type of the film is found to be tetragonal with particle size of the order of 32 nm. The structural parameters such as lattice constant, particle size, dislocation density, number of crystallites per unit area and strain in the film are also evaluated. The surface morphology of CuInSe2 films are studied using 2D and 3D atomic force microscopy to estimate the grain size and surface roughness respectively. Analysis of the absorption spectrum of the film recorded using UV-Vis-NIR Spectrophotometer in the wavelength range from 2500 nm to cutoff revealed that the film possess a direct allowed transition with a band gap of 1.05 eV and a high value of absorption coefficient (α) of 106 cm-1 at 570 nm. Photoconductivity at room temperature is measured after illuminating the film with an FSH lamp (82 V, 300 W). Optical absorption studies in conjunction with the good photoconductivity of the prepared p-type CuInSe2 thin films indicate its suitability in photovoltaic applications.

A Solution Processable High-Performance Thermoelectric Copper Selenide Thin Film.

PubMed

Lin, Zhaoyang; Hollar, Courtney; Kang, Joon Sang; Yin, Anxiang; Wang, Yiliu; Shiu, Hui-Ying; Huang, Yu; Hu, Yongjie; Zhang, Yanliang; Duan, Xiangfeng

2017-06-01

A solid-state thermoelectric device is attractive for diverse technological areas such as cooling, power generation and waste heat recovery with unique advantages of quiet operation, zero hazardous emissions, and long lifetime. With the rapid growth of flexible electronics and miniature sensors, the low-cost flexible thermoelectric energy harvester is highly desired as a potential power supply. Herein, a flexible thermoelectric copper selenide (Cu 2 Se) thin film, consisting of earth-abundant elements, is reported. The thin film is fabricated by a low-cost and scalable spin coating process using ink solution with a truly soluble precursor. The Cu 2 Se thin film exhibits a power factor of 0.62 mW/(m K 2 ) at 684 K on rigid Al 2 O 3 substrate and 0.46 mW/(m K 2 ) at 664 K on flexible polyimide substrate, which is much higher than the values obtained from other solution processed Cu 2 Se thin films (<0.1 mW/(m K 2 )) and among the highest values reported in all flexible thermoelectric films to date (≈0.5 mW/(m K 2 )). Additionally, the fabricated thin film shows great promise to be integrated with the flexible electronic devices, with negligible performance change after 1000 bending cycles. Together, the study demonstrates a low-cost and scalable pathway to high-performance flexible thin film thermoelectric devices from relatively earth-abundant elements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

NASA Astrophysics Data System (ADS)

Choudhary, Ritika; Chauhan, Rishi Pal

2017-07-01

The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide

DOE PAGES

Zeljkovic, Ilija; Scipioni, Kane L.; Walkup, Daniel; ...

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its highmore » energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. Finally, this opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.« less

Efficient cold cathode emission in crystalline-amorphous hybrid: Study on carbon nanotube-cadmium selenide system

NASA Astrophysics Data System (ADS)

Sarkar, S.; Banerjee, D.; Das, N. S.; Ghorai, U. K.; Sen, D.; Chattopadhyay, K. K.

2018-03-01

Cadmium Selenide (CdSe) quantum dot (QD) decorated amorphous carbon nanotubes (a-CNTs) hybrids have been synthesized by simple chemical process. The samples were characterized by field emission scanning and transmission electron microscopy, Fourier transformed infrared spectroscopy, Raman and UV-Vis spectroscopy. Lattice image obtained from transmission electron microscopic study confirms the successful attachment of CdSe QDs. It is seen that hybrid samples show an enhanced cold emission properties with good stability. The results have been explained in terms of increased roughness, more numbers of emitting sites and favorable band bending induced electron transport. ANSYS software based calculation has also supported the result. Also a first principle based study has been done which shows that due to the formation of hybrid structure there is a profound upward shift in the Fermi level, i.e. a decrease of work function, which is believed to be another key reason for the observed improved field emission performance.

Extraction processes and solvents for recovery of cesium, strontium, rare earth elements, technetium and actinides from liquid radioactive waste

DOEpatents

Zaitsev, Boris N.; Esimantovskiy, Vyacheslav M.; Lazarev, Leonard N.; Dzekun, Evgeniy G.; Romanovskiy, Valeriy N.; Todd, Terry A.; Brewer, Ken N.; Herbst, Ronald S.; Law, Jack D.

2001-01-01

Cesium and strontium are extracted from aqueous acidic radioactive waste containing rare earth elements, technetium and actinides, by contacting the waste with a composition of a complex organoboron compound and polyethylene glycol in an organofluorine diluent mixture. In a preferred embodiment the complex organoboron compound is chlorinated cobalt dicarbollide, the polyethylene glycol has the formula RC.sub.6 H.sub.4 (OCH.sub.2 CH.sub.2).sub.n OH, and the organofluorine diluent is a mixture of bis-tetrafluoropropyl ether of diethylene glycol with at least one of bis-tetrafluoropropyl ether of ethylene glycol and bis-tetrafluoropropyl formal. The rare earths, technetium and the actinides (especially uranium, plutonium and americium), are extracted from the aqueous phase using a phosphine oxide in a hydrocarbon diluent, and reextracted from the resulting organic phase into an aqueous phase by using a suitable strip reagent.

A study on the optics of copper indium gallium (di)selenide (CIGS) solar cells with ultra-thin absorber layers.

PubMed

Xu, Man; Wachters, Arthur J H; van Deelen, Joop; Mourad, Maurice C D; Buskens, Pascal J P

2014-03-10

We present a systematic study of the effect of variation of the zinc oxide (ZnO) and copper indium gallium (di)selenide (CIGS) layer thickness on the absorption characteristics of CIGS solar cells using a simulation program based on finite element method (FEM). We show that the absorption in the CIGS layer does not decrease monotonically with its layer thickness due to interference effects. Ergo, high precision is required in the CIGS production process, especially when using ultra-thin absorber layers, to accurately realize the required thickness of the ZnO, cadmium sulfide (CdS) and CIGS layer. We show that patterning the ZnO window layer can strongly suppress these interference effects allowing a higher tolerance in the production process.

The discovery of robust magnetism in a technetium oxide: The structure of CaTcO3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avdeev, Maxim; Thorogood, Gordon J.; Carter, Melody L.

The technetium perovskite CaTcO{sub 3} has been synthesized. Combining synchrotron X-ray and neutron diffraction, we found that CaTcO{sub 3} is an antiferromagnetic with a surprisingly high Neel temperature of 800 K. The transition to the magnetic state does not involve a structural change, but there is obvious magnetostriction. Electronic structure calculations confirm the experimental results.

Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors.

PubMed

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2018-01-19

In this work, bismuth selenides (Bi 2 Se 3 and Bi 3 Se 4 ), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi 2 Se 3 nanoplates exhibit much better performance as an electrode material than Bi 3 Se 4 nanoparticles do, delivering a higher specific capacitance (272.9 F g -1 ) than that of Bi 3 Se 4 (193.6 F g -1 ) at 5 mV s -1 . This result may be attributed to the fact that Bi 2 Se 3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi 3 Se 4 ). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi 2 Se 3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm -3 at 20 mV s -1 (Bi 3 Se 4 : 79.1 F cm -3 ), a high energy density of 17.9 mWh cm -3 and a high power density of 18.9 W cm -3 . The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi 2 Se 3 (Bi 3 Se 4 :90.3%). Clearly, Bi 2 Se 3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors

NASA Astrophysics Data System (ADS)

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2018-02-01

In this work, bismuth selenides (Bi2Se3 and Bi3Se4), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi2Se3 nanoplates exhibit much better performance as an electrode material than Bi3Se4 nanoparticles do, delivering a higher specific capacitance (272.9 F g-1) than that of Bi3Se4 (193.6 F g-1) at 5 mV s-1. This result may be attributed to the fact that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi3Se4). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi2Se3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm-3 at 20 mV s-1 (Bi3Se4: 79.1 F cm-3), a high energy density of 17.9 mWh cm-3 and a high power density of 18.9 W cm-3. The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi2Se3 (Bi3Se4:90.3%). Clearly, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

A Molecular Ni-complex Containing Tetrahedral Nickel Selenide Core as Highly Efficient Electrocatalyst for Water Oxidation.

PubMed

Masud, Jahangir; Ioannou, Polydoros-Chrysovalantis; Levesanos, Nikolaos; Kyritsis, Panayotis; Nath, Manashi

2016-11-23

We report the highly efficient catalytic activity of a transition metal selenide-based coordination complex, [Ni{(SeP i Pr 2 ) 2 N} 2 ], (1) for oxygen evolution and hydrogen evolution reactions (OER and HER, respectively) in alkaline solution. Very low overpotentials of 200 mV and 310 mV were required to achieve 10 mA cm -2 for OER and HER, respectively. The overpotential for OER is one of the lowest that has been reported up to now, making this one of the best OER electrocatalysts. In addition, this molecular complex exhibits an exceptionally high mass activity (111.02 A g -1 ) and a much higher TOF value (0.26 s -1 ) at a overpotential of 300 mV. This bifunctional electrocatalyst enables water electrolysis in alkaline solutions at a cell voltage of 1.54 V. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Remarkable photo-catalytic degradation of malachite green by nickel doped bismuth selenide under visible light irradiation

NASA Astrophysics Data System (ADS)

Kulsi, Chiranjit; Ghosh, Amrita; Mondal, Anup; Kargupta, Kajari; Ganguly, Saibal; Banerjee, Dipali

2017-01-01

Bismuth selenide (Bi2Se3) and nickel (Ni) doped Bi2Se3 were prepared by a solvothermal approach to explore the photo-catalytic performance of the materials in degradation of malachite green (MG). The presence of nickel was confirmed by X-ray photoelectron spectroscopy (XPS) measurement in doped Bi2Se3. The results showed that the nickel doping played an important role in microstructure and photo-catalytic activity of the samples. Nickel doped Bi2Se3 sample exhibited higher photo-catalytic activity than that of the pure Bi2Se3 sample under visible-light irradiation. The photo-catalytic degradation followed first-order reaction kinetics. Fast degradation kinetics and complete (100% in 5 min of visible light irradiation) removal of MG was achieved by nickel doped Bi2Se3 in presence of hydrogen peroxide (H2O2) due to modification of band gap energies leading to suppression of photo-generated electron-hole recombination.

Improved microstructure and thermoelectric properties of iodine doped indium selenide as a function of sintering temperature

NASA Astrophysics Data System (ADS)

Dhama, Pallavi; Kumar, Aparabal; Banerji, P.

2018-04-01

In this paper, we explored the effect of sintering temperature on the microstructure, thermal and electrical properties of iodine doped indium selenide in the temperature range 300 - 700 K. Samples were prepared by a collaborative process of vacuum melting, ball milling and spark plasma sintering at 570 K, 630 K and 690 K. Single phase samples were obtained at higher sintering temperature as InSe is stable only at lower temperature. With increasing sintering temperature, densities of the samples were found to improve with larger grain size formation. Negative values of Seebeck coefficient were observed which indicates n-type carrier transport. Seebeck coefficient increases with sintering temperature and found to be the highest for the sample sintered at 690 K. Thermal conductivity found to be lower in the samples sintered at lower temperatures. The maximum thermoelectric figure of merit found to be ˜ 1 at 700 K due to the enhanced power factor as a result of improved microstructure.

Technetium phosphate bone scan in the diagnosis of septic arthritis in childhood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundberg, S.B.; Savage, J.P.; Foster, B.K.

1989-09-01

The technetium phosphate bone scans of 106 children with suspected septic arthritis were reviewed to determine whether the bone scan can accurately differentiate septic from nonseptic arthropathy. Only 13% of children with proved septic arthritis had correct blind scan interpretation. The clinically adjusted interpretation did not identify septic arthritis in 30%. Septic arthritis was incorrectly identified in 32% of children with no evidence of septic arthritis. No statistically significant differences were noted between the scan findings in the septic and nonseptic groups and no scan findings correlated specifically with the presence or absence of joint sepsis.

Tellurite glasses for vitrification of technetium-99 from pyrochemical processing

NASA Astrophysics Data System (ADS)

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

2017-09-01

A new alkali-alumino tellurite glass composition was developed to immobilize highly-volatile technetium (Tc) wastes generated from the pyrochemical processing technology. Tellurite glass can incorporate up to 7 mass% of rhenium (Re, used as a surrogate for Tc) with an average retention of 86%. Normalized elemental releases evaluated by seven-day product consistency test (PCT) satisfied the immobilized low activity waste requirements of United States when concentration of Ca(ReO4)2 in the glass was <12 mass%. Re ions form Re7+ and are coordinated with four oxygens to form ReO4- tetrahedra. These tetrahedra bond to modifiers such as Ca2+ or Na+ that are further connected to the tellurite glass network by Ca2+ (or Na+) - non-bridging oxygen bonds.

The abdominal technetium scan (a decade of experience)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooney, D.R.; Duszynski, D.O.; Camboa, E.

1982-10-01

Out of 270 children with gastrointestinal symptoms, the indications for technetium scanning were: gastrointestinal tract bleeding (165 patients), abdominal pain (99 patients) and a history of intussusception (6 patients). Thirty children had abnormal findings, while the remaining 240 patients had normal scans. Four of the 30 children with positive scans were not explored, while the others underwent laparotomy. Of the 26 operated patients, 12 (46%) had a Meckel's diverticulum. Nine patients (34%) had other pathologic lesions that were detected by the scan. Five had true false positives as no pathologic lesions were found. Of the 240 children with negative scans,more » 19 were eventually explored because of persistent symptoms or clinical findings. Two of these had a Meckel's diverticulum. Eleven had a negative exploration while six had other surgical lesions. Technitium scan should reliably detect around 80%-90% of Meckel's diverticula. It will also accurately exclude the diagnosis of Meckel's diverticulum in over 90% of patients.« less

Periarticular uptake of /sup 99m/technetium diphosphonate in psoriatics. Correlation with cutaneous activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Namey, T.C.; Rosenthall, L.

1976-01-01

The periarticular uptake of /sup 99m/technetium-labeled diphosphonate (/sup 99m/TcDP) was compared in 12 patients hospitalized for psoriasis and in 12 hospitalized for other dermatoses not associated with arthropathy. The 12 patients with psoriasis had recent onset disease of less than 5 years duration; neither group had historical or clinical evidence of arthritis. All psoriatics had markedly abnormal scans with symmetrically increased periarticular uptake about the imaged joints. None of the controls had similar findings. In 4 patients scanned with /sup 99m/technetium-pertechnetate within 24 hours of their /sup 99m/TcDP scan, no evidence of inflammatory synovitis was found. Three of these patientsmore » were serially imaged with /sup 99m/TcDP at intervals of 2 weeks to 3 months after their initial study, when obvious clinical improvement in their psoriasis was apparent. Improvement in the radionuclide joint images was demonstrated in some of the patients, but none reverted to normal during the study period. In light of recent evidence for the preferential binding of /sup 99m/TcDP to immature collagen, it is suggested that psoriasis may represent a generalized, but uncharacterized, collagen disorder present in bone as well as skin, linking the cutaneous disease with the potential for arthropathy.« less

Experimental formation of Pb, Sn, Ge and Sb sulfides, selenides and chlorides in the presence of sal ammoniac: A contribution to the understanding of the mineral formation processes in coal wastes self-burning

NASA Astrophysics Data System (ADS)

Laufek, František; Veselovsky, František; Drábek, Milan; Kříbek, Bohdan; Klementová, Mariana

2017-04-01

The formation of sulfides, selenides and chlorides was experimentally studied at 800 or 900°C in the presence of sal ammoniac in a sealed silica glass tube. Synthetic PbS, PbSe, SnS, GeS, SnGeS2, PbSnS3, SnS and Sb2S3 or natural uraninite were used as a starting charge. Depending on the chemical composition of the sulfide/selenide charge, galena, unnamed SnGeS3 phase, herzenbergite, berndite, ottenmannite, stibnite and unnamed SnSb2S4 and Sn2Sb3S6 phases were identified in sublimates, together with cotunnite and an unnamed (NH4)2SnCl6 phase. When natural uraninite in a mixture with sal ammoniac was used as a charge, the reaction product comprised abundant cotunnite and minor challacolloite due to volatilization of radiogenic lead. When sulfur was introduced to the charge with uraninite and sal ammoniac, galena was found in reaction products. The results of our experiments revealed that if sulfide or selenide phases and NH4Cl are placed in a thermal gradient, it is possible to accelerate their mobility through a process of hydrogen chloride vapor transport. Within the transport process, new solid products are either isochemical or non-isochemical. The isochemical composition of resulting phases with charge probably represents simple sublimation of the original solid phase in form of self-vapor. The non-isochemical phases are probably formed due to combination of sublimation and condensation of various gas components including gaseous HCl. The valency change of metals (e.g. Sn2+ to Sn3+) in several reaction products indicates redox reactions in the gas mixture or during the solidification of resulting products. The role of ammoniac is not clear; however, formation of unnamed (NH4)2SnCl6 compound identified in one of our experiment, indicate possible formation of ammonium complexes. In contrast to experiments where sulfides or selenides were used as a part of charge, mobility of uraninite was not proved under experimental conditions employed. It is consistent with an

Surfactant mediated synthesis of bismuth selenide thin films for photoelectrochemical solar cell applications.

PubMed

Desai, Neha D; Khot, Kishorkumar V; Ghanwat, Vishvanath B; Kharade, Suvarta D; Bhosale, Popatrao N

2018-03-15

In the present report, nanostructured bismuth selenide (Bi 2 Se 3 ) thin films have been successfully deposited by using arrested precipitation technique (APT) at room temperature. The effect of three different surfactants on the optostructural, morphological, compositional and photoelectrochemical properties of Bi 2 Se 3 thin films were investigated. Optical absorption data indicates direct and allowed transition with a band gap energy varied from 1.4 eV to 1.8 eV. The X-ray diffraction pattern (XRD) revealed that Bi 2 Se 3 thin films are crystalline in nature and confirmed rhombohedral crystal structure. SEM micrographs shows morphological transition from interconnected mesh to nanospheres like and finally granular morphology. Surface topography of Bi 2 Se 3 thin films was determined by AFM. Compositional analysis of all samples was carried out by energy dispersive X-ray spectroscopy (EDS). Finally, all Bi 2 Se 3 thin films shows good PEC performance with highest photoconversion efficiency 1.47%. In order to study the stability of Bi 2 Se 3 thin films four cycles are repeated after gap of one week each. Further PEC performance of all Bi 2 Se 3 thin films are also supported by electrochemical impedance (EIS) measurement study. Copyright © 2017 Elsevier Inc. All rights reserved.

Ion Exchange Column Tests Supporting Technetium Removal Resin Maturation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, C.; McCabe, D.; Hamm, L.

2013-12-20

The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant, currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed on site. There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Due to the soluble properties of pertechnetate and long half-life ofmore » 99Tc, effective management of 99Tc is important. Options are being explored to immobilize the supplemental LAW portion of the tank waste, as well as to examine the volatility of 99Tc during the vitrification process. Removal of 99Tc, followed by off-site disposal has potential to reduce treatment and disposal costs. A conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. SuperLig® 639 is an elutable ion exchange resin. In the tank waste, 99Tc is predominantly found in the tank supernate as pertechnetate (TcO 4 -). Perrhenate (ReO 4 -) has been shown to be a good non-radioactive surrogate for pertechnetate in laboratory testing for this ion exchange resin. This report contains results of experimental ion exchange distribution coefficient and column resin maturation kinetics testing using the resin SuperLig® 639a to selectively remove perrhenate from simulated LAW. This revision includes results from testing to determine effective resin operating temperature range. Loading tests were performed at 45°C, and the computer modeling was updated to include the temperature effects. Equilibrium contact testing indicated that this batch of SuperLig® 639 resin has good performance, with an average perrhenate distribution coefficient of

Structural stability and mechanical properties of technetium mononitride (TcN)

NASA Astrophysics Data System (ADS)

Soni, Shubhangi; Choudhary, K. K.; Kaurav, Netram

2018-05-01

Among the nitrides, 3d and 4d transition metal nitrides have been investigated both experimentally and theoretically due to their predominant performances and enormous applications. In the present paper, we have attempted to predict the structural stability and mechanical properties of technetium mononitride (TcN) using an effective interionic interaction potential, which includes the long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach. Our theoretical approach reveals the structural phase transition of the TcN B3 to B1 structure, wherein, the Gibbs' free energies of both the structures were minimized. The variations of elastic constants with pressure follow a systematic trend identical to that observed in other compounds of ZnS type structure family.

Scintigraphic detection of occult hemorrhage using RBCs labeled in vitro with technetium Tc 99m sodium pertechnetate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunker, S.R.; Kolina, J.S.; Kaplan, K.A.

1983-05-01

Scintigraphy with RBCs labeled with technetium Tc 99m sodium pertechnetate effectively located the source of hemorrhage in a patient receiving long-term anticoagulant therapy. (The patient was initially seen with a large hematoma on the flank.) More important, the procedure was used to monitor activity in this otherwise-occult bleeding site. Scintigraphic studies may be useful in the management of these difficult clinical problems.

Thermo-optical characterization of cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots embedded in biocompatible materials.

PubMed

Pilla, Viviane; Alves, Leandro P; Iwazaki, Adalberto N; Andrade, Acácio A; Antunes, Andrea; Munin, Egberto

2013-09-01

Cadmium selenide/zinc sulfide (CdSe/ZnS) core-shell quantum dots (QDs) embedded in biocompatible materials were thermally and optically characterized with a thermal lens (TL) technique. Transient TL measurements were performed with a mode-mismatched, dual-beam (excitation and probe) configuration. A thermo-optical study of the CdSe/ZnS QDs was performed for different core diameters (3.5, 4.0, 5.2, and 6.6 nm) in aqueous solution and synthetic saliva, and three different core diameters (2.4, 2.9, and 4.1 nm) embedded in restorative dental resin (0.025% by mass). The thermal diffusivity results are characteristic of the biocompatible matrices. The radiative quantum efficiencies for aqueous solution and biofluid materials are dependent on the core size of the CdSe/ZnS core-shell QDs. The results obtained from the fluorescence spectral measurements for the biocompatible materials support the TL results.

Immobilization of Technetium in a Metallic Waste Form

DOE Office of Scientific and Technical Information (OSTI.GOV)

S.M. Frank; D. D. Keiser, Jr.; K. C. Marsden

Fission-product technetium accumulated during treatment of spent nuclear fuel will ultimately be disposed of in a geological repository. The exact form of Tc for disposal has yet to be determined; however, a reasonable solution is to incorporate elemental Tc into a metallic waste form similar to the waste form produced during the pyrochemical treatment of spent, sodium-bonded fuel. This metal waste form, produced at the Idaho National Laboratory, has undergone extensive qualification examination and testing for acceptance to the Yucca Mountain geological repository. It is from this extensive qualification effort that the behavior of Tc and other fission products inmore » the waste form has been elucidated, and that the metal waste form is extremely robust in the retention of fission products, such as Tc, in repository like conditions. This manuscript will describe the metal waste form, the behavior of Tc in the waste form; and current research aimed at determining the maximum possible loading of Tc into the metal waste and subsequent determination of the performance of high Tc loaded metal waste forms.« less

Lung ventilation studies with technetium-99m Pseudogas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burch, W.M.; Sullivan, P.J.; Lomas, F.E.

1986-06-01

Technetium-99m Pseudogas is an ultrafine near monodisperse aerosol of 0.12-microgram diam particle size. This report describes initial clinical experiences with 27 patients referred for investigation of suspected pulmonary embolism, and in whom Pseudogas ventilation images were compared with a high quality commercial aerosol. An additional group of ten patients with severe COPD was examined in a comparative trial of Pseudogas with 81mKr. Pseudogas was better than a conventional aerosol in reaching a diagnosis of pulmonary embolism using a simple blinded comparison with coded images. In addition, bronchial deposition was minimal unless COPD was severe. Moderately well patients had no difficultymore » inhaling the necessary activity in one or two breaths, and even severely ill and frail aged persons could accomplish the passive breathing maneuver in less than a minute. Clearance of Pseudogas was directly to the systemic circulation with a half-time of 10 min in normal subjects extending up to 100 min in patients with airways disease.« less

Technetium-99m stannous pyrophosphate myocardial scintigraphy after cardiopulmonary resuscitation with cardioversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davison, R.; Spies, S.M.; Przybylek, J.

1979-08-01

Thirty consecutive patients underwent technetium-99m stannous pyrophosphate myocardial scintigraphy 48 to 72 h after successful cardiopulmonary resuscitation and direct current cardioversion. Five patients with transmural myocardial infarctions by ECG and enzyme determinations were correctly identified by scintigraphy. Myocardial scans were positive in five of nine patients with nontransmural infarction. Of 16 patients without evidence of myocardial infarction, only two (13%) had false-positive myocardial scans. The overall accuracy of imaging in this series was 80%. We conclude that false-positive scans after cardiopulmonary resuscitation with electrical cardioversion are infrequent, and do not significantly detract from the value of myocardial scintigraphy in themore » diagnosis of myocardial infarction.« less

Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals

DOE PAGES

Li, Xufan; Basile Carrasco, Leonardo A.; Yoon, Mina; ...

2015-01-21

Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0° or 60° interlayer rotations. The commensurate stacking configurations (AA' and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale andmore » the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. Here, the combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.« less

Characterization of Technetium Speciation in Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Jung, Hun Bok; Wang, Guohui

2013-11-11

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Production and Long-Term Performance of Low Temperature Waste Forms” to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability frommore » Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.« less

Development of a remote spectroelectrochemical sensor for technetium as pertechnetate

NASA Astrophysics Data System (ADS)

Monk, David James

Subsurface contamination by technetium (Tc) is of particular concern in the monitoring, characterization, and remediation of underground nuclear waste storage tanks, processing areas, and associated surroundings at the Hanford Site and other U.S. DOE sites nationwide. The concern over this radioactive element arises for two reasons. First, its most common isotope, 99Tc, has an extremely long lifetime of 2.15 x 105 years. Second, it's most common chemical form in environmental conditions, pertechnetate (TcO4-), exhibits very fast migration through soils and readily presents itself to any nearby aquifer. Standard procedures of sampling and analysis in a laboratory prove to be slow and costly in the case of subsurface contamination by radioactive materials. It is highly desirable to develop sensors for these materials that possess the capability of either in-situ or on-site placement for continuous monitoring or immediate analysis of collected samples. These sensors need to possess adequate detection limit and selectivity, rapid response, reversibility (many measurements with one sensor), the ability to perform remotely, and ruggedness. This dissertation describes several areas of the continued work toward a sensor for 99Tc as TcO4-. Research initially focused on developing spectroelectrochemical instrumentation and a disposable sensing element, engineered to address the need to perform remote measurements. The instrument was then tested using samples containing 99Tc, resulting in the development of ancillary equipment and techniques to address concerns associated with performing experiments on radioactive materials. In these tests, the electrochemistry of TcO4 - was demonstrated to be irreversible. Electrochemical reduction of TcO4- on a bare or polymer modified electrode resulted in the continuous build up of technetium oxide (TcO2) on the electrode surface. This TcO2 formed in visual quantities in these films during electrochemistry, and proved to be non-ideal for

Importance of methodology on (99m)technetium dimercapto-succinic acid scintigraphic image quality: imaging pilot study for RIVUR (Randomized Intervention for Children With Vesicoureteral Reflux) multicenter investigation.

PubMed

Ziessman, Harvey A; Majd, Massoud

2009-07-01

We reviewed our experience with (99m)technetium dimercapto-succinic acid scintigraphy obtained during an imaging pilot study for a multicenter investigation (Randomized Intervention for Children With Vesicoureteral Reflux) of the effectiveness of daily antimicrobial prophylaxis for preventing recurrent urinary tract infection and renal scarring. We analyzed imaging methodology and its relation to diagnostic image quality. (99m)Technetium dimercapto-succinic acid imaging guidelines were provided to participating sites. High-resolution planar imaging with parallel hole or pinhole collimation was required. Two core reviewers evaluated all submitted images. Analysis included appropriate views, presence or lack of patient motion, adequate magnification, sufficient counts and diagnostic image quality. Inter-reader agreement was evaluated. We evaluated 70, (99m)technetium dimercapto-succinic acid studies from 14 institutions. Variability was noted in methodology and image quality. Correlation (r value) between dose administered and patient age was 0.780. For parallel hole collimator imaging good correlation was noted between activity administered and counts (r = 0.800). For pinhole imaging the correlation was poor (r = 0.110). A total of 10 studies (17%) were rejected for quality issues of motion, kidney overlap, inadequate magnification, inadequate counts and poor quality images. The submitting institution was informed and provided with recommendations for improving quality, and resubmission of another study was required. Only 4 studies (6%) were judged differently by the 2 reviewers, and the differences were minor. Methodology and image quality for (99m)technetium dimercapto-succinic acid scintigraphy varied more than expected between institutions. The most common reason for poor image quality was inadequate count acquisition with insufficient attention to the tradeoff between administered dose, length of image acquisition, start time of imaging and resulting image

Combined technetium radioisotope penile plethysmography and xenon washout: A technique for evaluating corpora cavernosal inflow and outflow during early tumescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwartz, A.N.; Graham, M.M.

1991-03-01

Combined technetium radioisotope penile plethysmography and xenon washout is a new technique that measures both corporal arterial inflow and venous sinusoidal outflow during early tumescence in patients with erectile dysfunction. Fourteen patients were studied using 99mTc-RBCs to measure inflow and 133Xe or 127Xe in saline to measure outflow. Tumescence was induced by injecting papaverine intracorporally. Peak corporal rates corrected for inflow (r = 0.88) and uncorrected for outflow (r = 0.91) and change in volume over 2 min centered around peak inflow (r = 0.96) all correlated with angiography. Outflow measurements did not correlate with intracorporal resistance. Thus, outflow ratesmore » alone could not be used to predict venous sinusoidal competence. Normal inflow rate is greater than 20 ml/min; probable normal 12-20; indeterminate inflow 7-12; and abnormal inflow less than 7 ml/min. Technetium-99m radioisotope penile plethysmography and xenon washout can be performed together and both provide a method for simultaneously evaluating the relationship between corporal inflow and outflow rates in patients with erectile dysfunction.« less

Lead Selenide Colloidal Quantum Dot Solar Cells Achieving High Open-Circuit Voltage with One-Step Deposition Strategy.

PubMed

Zhang, Yaohong; Wu, Guohua; Ding, Chao; Liu, Feng; Yao, Yingfang; Zhou, Yong; Wu, Congping; Nakazawa, Naoki; Huang, Qingxun; Toyoda, Taro; Wang, Ruixiang; Hayase, Shuzi; Zou, Zhigang; Shen, Qing

2018-06-18

Lead selenide (PbSe) colloidal quantum dots (CQDs) are considered to be a strong candidate for high-efficiency colloidal quantum dot solar cells (CQDSCs) due to its efficient multiple exciton generation. However, currently, even the best PbSe CQDSCs can only display open-circuit voltage ( V oc ) about 0.530 V. Here, we introduce a solution-phase ligand exchange method to prepare PbI 2 -capped PbSe (PbSe-PbI 2 ) CQD inks, and for the first time, the absorber layer of PbSe CQDSCs was deposited in one step by using this PbSe-PbI 2 CQD inks. One-step-deposited PbSe CQDs absorber layer exhibits fast charge transfer rate, reduced energy funneling, and low trap assisted recombination. The champion large-area (active area is 0.35 cm 2 ) PbSe CQDSCs fabricated with one-step PbSe CQDs achieve a power conversion efficiency (PCE) of 6.0% and a V oc of 0.616 V, which is the highest V oc among PbSe CQDSCs reported to date.

Facile hot-injection synthesis of stoichiometric Cu2ZnSnSe4 nanocrystals using bis(triethylsilyl) selenide.

PubMed

Jin, Chunyu; Ramasamy, Parthiban; Kim, Jinkwon

2014-07-07

Cu2ZnSnSe4 is a prospective material as an absorber in thin film solar cells due to its many advantages including direct band gap, high absorption coefficient, low toxicity, and relative abundance (indium-free) of its elements. In this report, CZTSe nanoparticles have been synthesized by the hot-injection method using bis-(triethylsilyl)selenide [(Et3Si)2Se] as the selenium source for the first time. Energy dispersive X-ray spectroscopy (EDS) confirmed the stoichiometry of CZTSe nanoparticles. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the nanocrystals were single phase polycrystalline with their size within the range of 25-30 nm. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy measurements ruled out the existence of secondary phases such as Cu2SnSe3 and ZnSe. The effect of reaction time and precursor injection order on the formation of stoichiometric CZTSe nanoparticles has been studied by Raman spectroscopy. UV-vis-NIR data indicate that the CZTSe nanocrystals have an optical band gap of 1.59 eV, which is optimal for photovoltaic applications.

Investigation of Electronic and Opto-Electronic Properties of Two-Dimensional (2D) Layers of Copper Indium Selenide Field Effect Transistors

NASA Astrophysics Data System (ADS)

Patil, Prasanna Dnyaneshwar

Investigations performed in order to understand the electronic and optoelectronic properties of field effect transistors based on few layers of 2D Copper Indium Selenide (CuIn7Se11) are reported. In general, field effect transistors (FETs), electric double layer field effect transistors (EDL-FETs), and photodetectors are crucial part of several electronics based applications such as tele-communication, bio-sensing, and opto-electronic industry. After the discovery of graphene, several 2D semiconductor materials like TMDs (MoS2, WS2, and MoSe2 etc.), group III-VI materials (InSe, GaSe, and SnS2 etc.) are being studied rigorously in order to develop them as components in next generation FETs. Traditionally, thin films of ternary system of Copper Indium Selenide have been extensively studied and used in optoelectronics industry as photoactive component in solar cells. Thus, it is expected that atomically thin 2D layered structure of Copper Indium Selenide can have optical properties that could potentially be more advantageous than its thin film counterpart and could find use for developing next generation nano devices with utility in opto/nano electronics. Field effect transistors were fabricated using few-layers of CuIn7Se11 flakes, which were mechanically exfoliated from bulk crystals grown using chemical vapor transport technique. Our FET transport characterization measurements indicate n-type behavior with electron field effect mobility microFE ≈ 36 cm2 V-1 s-1 at room temperature when Silicon dioxide (SiO2) is used as a back gate. We found that in such back gated field effect transistor an on/off ratio of 104 and a subthreshold swing ≈ 1 V/dec can be obtained. Our investigations further indicate that Electronic performance of these materials can be increased significantly when gated from top using an ionic liquid electrolyte [1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6)]. We found that electron field effect mobility microFE can be increased from

Incorporating technetium in minerals and other solids: A review

NASA Astrophysics Data System (ADS)

Luksic, Steven A.; Riley, Brian J.; Schweiger, Michael; Hrma, Pavel

2015-11-01

Technetium (Tc) can be incorporated into a number of different solids including spinel, sodalite, rutile, tin dioxide, pyrochlore, perovskite, goethite, layered double hydroxides, cements, and alloys. Synthetic routes are possible for each of these phases, ranging from high-temperature ceramic sintering to ball-milling of constituent oxides. However, in practice, Tc has only been incorporated into solid materials by a limited number of the possible syntheses. A review of the diverse ways in which Tc-immobilizing materials can be made shows the wide range of options available. Special consideration is given to hypothetical application to the Hanford Tank Waste and Vitrification Plant, such as adding a Tc-bearing mineral to waste glass melter feed. A full survey of solid Tc waste forms, the common synthesis routes to those waste forms, and their potential for application to vitrification processes are presented. The use of tin dioxide or ferrite spinel precursors to reduce Tc(VII) out of solution and into a durable form are shown to be of especially high potential.

Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions

USGS Publications Warehouse

Herbel, M.J.; Blum, J.S.; Oremland, R.S.; Borglin, S.E.

2003-01-01

A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe-) when supplied with Se(O). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(O) to Se(-II). Reduction of Se(O) by B.selenitireducens was more rapid in cells grown on colloidal sulfur [S(O)] or Se(IV) as their electron acceptor than for cell lines grown on fumarate. In contrast, three cultures of selenate-respiring bacteria, Sulfurospirillum barnesii, B. arsenicoselenatis, and Selenihalanaerobacter shriftii either were unable to reduce Se(O) to Se(-II) or had only a very limited capacity to achieve this reduction. Biological reduction of Se(O) to Se(-II) was observed during incubation of estuarine sediment slurries, while no such activity was noted in formalin-killed controls. The majority of the Se(-II) produced was found in the sediments as a solid precipitate of FeSe, rather than in solution as HSe-. These results demonstrate that certain anaerobic bacteria have the capacity to reduce Se(O) to Se(-II), providing a possible biological explanation for the occurrence of the selenide species in some sedimentary rocks.

Recovery and Determination of Adsorbed Technetium on Savannah River Site Charcoal Stack Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lahoda, Kristy G.; Engelmann, Mark D.; Farmer, Orville T.

2008-03-01

Experimental results are provided for the sample analyses for technetium (Tc) in charcoal samples placed in-line with a Savannah River Site (SRS) processing stack effluent stream as a part of an environmental surveillance program. The method for Tc removal from charcoal was based on that originally developed with high purity charcoal. Presented is the process that allowed for the quantitative analysis of 99Tc in SRS charcoal stack samples with and without 97Tc as a tracer. The results obtained with the method using the 97Tc tracer quantitatively confirm the results obtained with no tracer added. All samples contain 99Tc at themore » pg g-1 level.« less

Structural and electrochemical analysis of chemically synthesized microcubic architectured lead selenide thin films

NASA Astrophysics Data System (ADS)

Bhat, T. S.; Shinde, A. V.; Devan, R. S.; Teli, A. M.; Ma, Y. R.; Kim, J. H.; Patil, P. S.

2018-01-01

The present work deals with the synthesis of lead selenide (PbSe) thin films by simple and cost-effective chemical bath deposition method with variation in deposition time. The structural, morphological, and electrochemical properties of as-deposited thin films were examined using characterization techniques such as X-ray diffraction spectroscopy (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy. XRD reveals formation of rock salt phase cubic structured PbSe. FE-SEM images show the formation of microcubic structured morphology. The existence of the PbSe is confirmed from the XPS analysis. On the other hand, CV curves show four reaction peaks corresponding to oxidation [PbSe and Pb(OH)2] and reduction (PbO2 and Pb(OH)2) at the surface of PbSe thin films. The PbSe:2 sample deposited for 80 min. shows maximum specific capacitance of 454 ± 5 F g- 1 obtained at 0.25 mA cm- 2 current density. The maximum energy density of 69 Wh kg- 1 was showed by PbSe:2 electrode with a power density of 1077 W kg- 1. Furthermore, electrochemical impedance studies of PbSe:2 thin film show 80 ± 3% cycling stability even after 500 CV cycles. Such results show the importance of microcubic structured PbSe thin film as an anode in supercapacitor devices.

Thin-film copper indium gallium selenide solar cell based on low-temperature all-printing process.

PubMed

Singh, Manjeet; Jiu, Jinting; Sugahara, Tohru; Suganuma, Katsuaki

2014-09-24

In the solar cell field, development of simple, low-cost, and low-temperature fabrication processes has become an important trend for energy-saving and environmental issues. Copper indium gallium selenide (CIGS) solar cells have attracted much attention due to the high absorption coefficient, tunable band gap energy, and high efficiency. However, vacuum and high-temperature processing in fabrication of solar cells have limited the applications. There is a strong need to develop simple and scalable methods. In this work, a CIGS solar cell based on all printing steps and low-temperature annealing is developed. CIGS absorber thin film is deposited by using dodecylamine-stabilized CIGS nanoparticle ink followed by printing buffer layer. Silver nanowire (AgNW) ink and sol-gel-derived ZnO precursor solution are used to prepare a highly conductive window layer ZnO/[AgNW/ZnO] electrode with a printing method that achieves 16 Ω/sq sheet resistance and 94% transparency. A CIGS solar cell based on all printing processes exhibits efficiency of 1.6% with open circuit voltage of 0.48 V, short circuit current density of 9.7 mA/cm(2), and fill factor of 0.34 for 200 nm thick CIGS film, fabricated under ambient conditions and annealed at 250 °C.

Development of bismuth tellurium selenide nanoparticles for thermoelectric applications via a chemical synthetic process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Cham; Department of Chemical Engineering, Pohang University of Science and Technology; Kim, Dong Hwan

2011-03-15

Research highlights: {yields} We synthesized a Bi{sub 2}Te{sub y}Se{sub 3-y} nano-compound via a chemical synthetic process. {yields} The compound was sintered to achieve an average grain size of about 300 nm. {yields} The resulting sintered body showed very low thermal conductivity. It is likely caused by the vigorous phonon scattering of the nano-sized grains. -- Abstract: Bismuth tellurium selenide (Bi{sub 2}Te{sub y}Se{sub 3-y}) nanoparticles for thermoelectric applications are successfully prepared via a water-based chemical reaction under atmospheric conditions. The nanostructured compound is prepared using a complexing agent (ethylenediaminetetraacetic acid) and a reducing agent (ascorbic acid) to stabilize the bismuth precursormore » (Bi(NO{sub 3}){sub 3}) in water and to favor the reaction with reduced sources of tellurium and selenium. The resulting powder is smaller than ca. 100 nm and has a crystalline structure corresponding to the rhombohedral Bi{sub 2}Te{sub 2.7}Se{sub 0.3}. The nanocrystalline powder is sintered via a spark plasma sintering process to obtain a sintered body composed of nano-sized grains. Important transport properties of the sintered body are measured to calculate its most important characteristic, the thermoelectric performance. The results demonstrate a relationship between the nanostructure of the sintered body and its thermal conductivity.« less

Coexistence of multiphase superconductivity and ferromagnetism in lithiated iron selenide hydroxide [(L i1 -xF ex) OH ]FeSe

NASA Astrophysics Data System (ADS)

Urban, Christian; Valmianski, Ilya; Pachmayr, Ursula; Basaran, Ali C.; Johrendt, Dirk; Schuller, Ivan K.

2018-01-01

We present experimental evidence for (a) multiphase superconductivity and (b) coexistence of magnetism and superconductivity in a single structural phase of lithiated iron selenide hydroxide [(L i1 -xF ex )OH]FeSe. Magnetic field modulated microwave spectroscopy data confirms superconductivity with at least two distinct transition temperatures attributed to well-defined superconducting phases at TSC 1=40 ±2 K and TSC 2=35 ±2 K. Magnetometry data for the upper critical fields reveal a change in the magnetic order (TM=12 K) below TSC 1 and TSC 2 that is consistent with ferromagnetism. This occurs because the superconducting coherence length is much smaller than the structural coherence length, allowing for several different electronic and magnetic states on a single crystallite. The results give insight into the physics of complex multinary materials, where several phenomena governed by different characteristic length scales coexist.

Influence of Post-Heat Treatment of ZnO:Al Transparent Electrode for Copper Indium Gallium Selenide Thin Film Solar Cell.

PubMed

Eom, Taewoo; Park, Jeong Eun; Park, Sang Yong; Park, Jeong Hoon; Bweupe, Jackson; Lim, Donggun

2018-09-01

Copper indium gallium selenide (CIGS) thin film solar cells have been regarded as a candidate for energy conversion devices owing to their high absorption coefficient, high temperature stability, and low cost. ZnO:Al thin film is commonly used in CIGS solar cells as a window layer. In this study, ZnO:Al films were deposited on glass under various post-heat temperature using RF sputtering to observe the characteristics of ZnO:Al films such as Hall mobility, carrier concentration, and resistivity; subsequently, the ZnO:Al films were applied to a CIGS solar cell as a window. CIGS solar cells fabricated with various ZnO:Al films were analyzed in order to investigate their influence. The test results showed that the improvement of ZnO:Al characteristics affects Jsc and Voc in the solar cell through reduced recombination and increase of optical property.

Literature review of the potential impact of glycolic acid on the technetium chemistry of srs tank waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, Charles A.; McCabe, Daniel J.

This document presents a literature study of the impact of glycolate on technetium chemistry in the Savannah River Site (SRS) waste system and specifically Saltstone. A predominant portion of the Tc at SRS will be sent to the Saltstone Facility where it will be immobilized. The Tc in the tank waste is in the highly soluble chemical form of pertechnetate ion (TcO 4 -) which is reduced by blast furnace slag (BFS) in Saltstone, rendering it highly insoluble and resistant to leaching.

The role of technetium-99m stannous pyrophosphate in myocardial imaging to recognize, localize and identify extension of acute myocardial infarction in patients

NASA Technical Reports Server (NTRS)

Willerson, J. T.; Parkey, R. W.; Bonte, F. J.; Stokely, E. M.; Buja, E. M.

1975-01-01

The ability of technetium-99m stannous pyrophosphate myocardial scintigrams to aid diagnostically in recognizing, localizing, and identifying extension of acute myocardial infarction in patients was evaluated. The present study is an extension of previous animal and patient evaluations that were recently performed utilizing this myocardial imaging agent.

Effect of Molecular Interactions on Electron-Transfer and Antioxidant Activity of Bis(alkanol)selenides: A Radiation Chemical Study.

PubMed

Kumar, Pavitra V; Singh, Beena G; Phadnis, Prasad P; Jain, Vimal K; Priyadarsini, K Indira

2016-08-16

Understanding electron-transfer processes is crucial for developing organoselenium compounds as antioxidants and anti-inflammatory agents. To find new redox-active selenium antioxidants, we have investigated one-electron-transfer reactions between hydroxyl ((.) OH) radical and three bis(alkanol)selenides (SeROH) of varying alkyl chain length, using nanosecond pulse radiolysis. (.) OH radical reacts with SeROH to form radical adduct, which is converted primarily into a dimer radical cation (>Se∴Se<)(+) and α-{bis(hydroxyl alkyl)}-selenomethine radical along with a minor quantity of an intramolecularly stabilized radical cation. Some of these radicals have been subsequently converted to their corresponding selenoxide, and formaldehyde. Estimated yield of these products showed alkyl chain length dependency and correlated well with their antioxidant ability. Quantum chemical calculations suggested that compounds that formed more stable (>Se∴Se<)(+) , produced higher selenoxide and lower formaldehyde. Comparing these results with those for sulfur analogues confirmed for the first time the distinctive role of selenium in making such compounds better antioxidants. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit

NASA Astrophysics Data System (ADS)

O'Hara, Dante J.; Zhu, Tiancong; Trout, Amanda H.; Ahmed, Adam S.; Luo, Yunqiu Kelly; Lee, Choong Hee; Brenner, Mark R.; Rajan, Siddharth; Gupta, Jay A.; McComb, David W.; Kawakami, Roland K.

2018-05-01

Monolayer van der Waals (vdW) magnets provide an exciting opportunity for exploring two-dimensional (2D) magnetism for scientific and technological advances, but the intrinsic ferromagnetism has only been observed at low temperatures. Here, we report the observation of room temperature ferromagnetism in manganese selenide (MnSe$_x$) films grown by molecular beam epitaxy (MBE). Magnetic and structural characterization provides strong evidence that in the monolayer limit, the ferromagnetism originates from a vdW manganese diselenide (MnSe$_2$) monolayer, while for thicker films it could originate from a combination of vdW MnSe$_2$ and/or interfacial magnetism of $\\alpha$-MnSe(111). Magnetization measurements of monolayer MnSe$_x$ films on GaSe and SnSe$_2$ epilayers show ferromagnetic ordering with large saturation magnetization of ~ 4 Bohr magnetons per Mn, which is consistent with density functional theory calculations predicting ferromagnetism in monolayer 1T-MnSe$_2$. Growing MnSe$_x$ films on GaSe up to high thickness (~ 40 nm) produces $\\alpha$-MnSe(111), and an enhanced magnetic moment (~ 2x) compared to the monolayer MnSe$_x$ samples. Detailed structural characterization by scanning transmission electron microscopy (STEM), scanning tunneling microscopy (STM), and reflection high energy electron diffraction (RHEED) reveal an abrupt and clean interface between GaSe(0001) and $\\alpha$-MnSe(111). In particular, the structure measured by STEM is consistent with the presence of a MnSe$_2$ monolayer at the interface. These results hold promise for potential applications in energy efficient information storage and processing.

Electric double-layer transistor using layered iron selenide Mott insulator TlFe1.6Se2

PubMed Central

Katase, Takayoshi; Hiramatsu, Hidenori; Kamiya, Toshio; Hosono, Hideo

2014-01-01

A1–xFe2–ySe2 (A = K, Cs, Rb, Tl) are recently discovered iron-based superconductors with critical temperatures (Tc) ranging up to 32 K. Their parent phases have unique properties compared with other iron-based superconductors; e.g., their crystal structures include ordered Fe vacancies, their normal states are antiferromagnetic (AFM) insulating phases, and they have extremely high Néel transition temperatures. However, control of carrier doping into the parent AFM insulators has been difficult due to their intrinsic phase separation. Here, we fabricated an Fe-vacancy-ordered TlFe1.6Se2 insulating epitaxial film with an atomically flat surface and examined its electrostatic carrier doping using an electric double-layer transistor (EDLT) structure with an ionic liquid gate. The positive gate voltage gave a conductance modulation of three orders of magnitude at 25 K, and further induced and manipulated a phase transition; i.e., delocalized carrier generation by electrostatic doping is the origin of the phase transition. This is the first demonstration, to the authors' knowledge, of an EDLT using a Mott insulator iron selenide channel and opens a way to explore high Tc superconductivity in iron-based layered materials, where carrier doping by conventional chemical means is difficult. PMID:24591598

Detection of homing-in of stem cells labeled with technetium-99m hexamethylpropyleneamine oxime in infarcted myocardium after intracoronary injection

PubMed Central

Patel, Chetan D; Agarwal, Snehlata; Seth, Sandeep; Mohanty, Sujata; Aggarwal, Himesh; Gupta, Namit

2014-01-01

Bone marrow stem cells having myogenic potential are promising candidates for various cell-based therapies for myocardial disease. We present here images showing homing of technetium-99m (Tc-99m) hexamethylpropyleneamine oxime (HMPAO) labeled stem cells in the infarcted myocardium from a pilot study conducted to radio-label part of the stem cells in patients enrolled in a stem cell clinical trial for recent myocardial infarction. PMID:25400375

Effect of Technetium-99 sources on its retention in low activity waste glass

NASA Astrophysics Data System (ADS)

Luksic, Steven A.; Kim, Dong-Sang; Um, Wooyong; Wang, Guohui; Schweiger, Michael J.; Soderquist, Chuck Z.; Lukens, Wayne; Kruger, Albert A.

2018-05-01

Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO2•2H2O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. We postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.

Fast dynamic electron transfer along infinite anion-cation chains in technetium and rhenium acido clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antipov, B.G.; Kryuchkov, S.V.; Grigor`ev, M.S.

1995-09-01

New technetium and rhenium compounds with ferricenium cations - [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}], and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Re{sub 2}Br{sub 8}] - are synthesized and identified. The compounds are characterized by the methods of static magnetic susceptibility and differential scanning calorimetry; solid-state conductivity measurements; and IR, EPR, {sup 57}Fe Moessbauer, and X-ray photoelectron spectroscopic data. These data are compared with the physicochemical characteristics of ferricenium pertechnetate and hexachlorotechnetate, as well as of a number of reference technetium and rhenium compounds containing the samemore » anions but different cations. The structure of [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}] is determined by X-ray diffraction analysis of a single crystal [space group P6/m, a = 15.34(2), c = 12.70(1) {angstrom}]. The structures of the remaining compounds were confirmed by comparing their spectroscopic properties with corresponding properties of compounds with known composition and structure. None of the compounds with ferricenium cations exhibit covalent or other localized bonds between anions and cations. However, the physicochemical properties of these compounds indicate the occurrence of a fast dynamic electron transfer along infinite anion-cation chains. Compounds [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}] and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}] were found to exhibit a new phenomenon of X-ray-induced low-temper ature high-energy electron emission.« less

Four two-dimensional ternary selenides based on group 13 and 14 metals: Syntheses, crystal structures, and electrochemical properties

NASA Astrophysics Data System (ADS)

Wang, Jingrui; Li, Peng; Cai, Ting; Yang, Dan-Dan; Xiong, Wei-Wei

2018-07-01

A series of two-dimensional ternary selenides, [NH4]2[Ga2Sn2Se8] (1), [NH4]2[In2Ge2Se8] (2), [NH4]2[In2Sn2Se8] (3), [NH4]2[Ga2Ge2Se8] (4), have been solvothermally synthesized and characterized by single crystal X-ray diffraction, energy dispersive X-ray (EDX) spectroscopy, solid-state UV-Vis diffuse reflectance spectroscopy, and thermogravimetric analyses. The solid-state optical absorption spectra indicated that these compounds were semiconductors with band gaps of 1.71 eV for 1, 1.95 eV for 2, 1.85 eV for 3, and 1.83 eV for 4. In addition, compound 2 was employed as an anode material for lithium ion battery application, which exhibited a high specific capacity of 479 mA h g-1 over 200 cycles at a current density of 200 mA g-1, and an excellent rate capability of 425.2 mA h g-1 at a current density of 1000 mA g-1. Our results suggest that crystalline chalcogenides could be an alternative anode material for high performance LIBs application.

Ab-initio study of B{sub 2}-type technetium AB (A=Tc, B=Nb and Ta) intermetallic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acharya, Nikita, E-mail: acharyaniks30@gmail.com; Fatima, Bushra; Sanyal, Sankar P.

2016-05-06

The structural, electronic and elastic properties of AB type (A = Tc, B = Nb and Ta) technetium intermetallic compounds are studied using full potential linearized plane wave (FP-LAPW) method within generalized gradient approximation (GGA). The calculated lattice parameters agree well with the experimental results. The elastic constants obey the stability criteria for cubic system. Ductility for these compounds has been analyzed using the Pugh’s rule and Cauchy’s pressure and found that all the compounds are ductile in nature. Bonding nature is discussed in terms of Fermi surface and band structures.

Eosinophilic enterocolitis diagnosed by means of technetium-99m albumin scintigraphy and treated with budesonide (CIR).

PubMed Central

Russel, M G; Zeijen, R N; Brummer, R J; de Bruine, A P; van Kroonenburgh, M J; Stockbrügger, R W

1994-01-01

A patient with a 15 year history of diarrhoea of unknown origin is described. Scintigraphy with technetium-99m labelled albumin suggested albumin loss at the terminal ileum and caecum; subsequent colonoscopic biopsies of these macroscopically normal looking areas showed abundant infiltration with eosinophils. A diagnosis of eosinophilic enterocolitis was made. Treatment with prednisolone had good results, but had to be stopped because of severe side effects. Oral cromoglycate and mesalazine were not effective. Budesonide (CIR), a new topically active corticosteroid with very little systemic effects, was at least as effective as prednisolone without producing side effects. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7959211

Technetium-99m production issues in the United Kingdom.

PubMed

Green, Christopher H

2012-04-01

Nuclear Medicine developed when it was realised that a radioisotopic substitution of Iodine-131 for the stable Iodine-127 would follow the same metabolic pathway in the body enabling the thyroid to be imaged and the thyroid uptake measured. The Iodine could be complexed with pharmaceutical substrates to enable other organs to be imaged, but its use was limited and high gamma energy and beta emission restricted the activity of each radiopharmaceutical used, leading to long acquisition times and degraded images. As a pure gamma emitter of 140 keV and with a 6-h half-life, Technetium-99m is a better radionuclide and images a wider range of bodily organs. However, its short half-life also requires it to be eluted from its mother radionuclide, Mo-99, in a generator, delivered weekly from radiopharmaceutical companies who obtain the Mo-99 in liquid form from high-flux research reactors. All went well till around 2007, when the NRU Reactor in Canada was closed and all other reactors went down for various periods for unrelated problems, leading to widespread Mo-99 shortages. Although the reactors have since recovered, they are 48 to 57 years old, and it seems that few governments have made any future provision such as building replacement reactors.

Technetium-99m production issues in the United Kingdom

PubMed Central

Green, Christopher H.

2012-01-01

Nuclear Medicine developed when it was realised that a radioisotopic substitution of Iodine-131 for the stable Iodine-127 would follow the same metabolic pathway in the body enabling the thyroid to be imaged and the thyroid uptake measured. The Iodine could be complexed with pharmaceutical substrates to enable other organs to be imaged, but its use was limited and high gamma energy and beta emission restricted the activity of each radiopharmaceutical used, leading to long acquisition times and degraded images. As a pure gamma emitter of 140 keV and with a 6-h half-life, Technetium-99m is a better radionuclide and images a wider range of bodily organs. However, its short half-life also requires it to be eluted from its mother radionuclide, Mo-99, in a generator, delivered weekly from radiopharmaceutical companies who obtain the Mo-99 in liquid form from high-flux research reactors. All went well till around 2007, when the NRU Reactor in Canada was closed and all other reactors went down for various periods for unrelated problems, leading to widespread Mo-99 shortages. Although the reactors have since recovered, they are 48 to 57 years old, and it seems that few governments have made any future provision such as building replacement reactors. PMID:22557795

Effect of Technetium-99 sources on its retention in low activity waste glass

DOE PAGES

Luksic, Steven A.; Kim, Dong Sang; Um, Wooyong; ...

2018-03-02

Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO 2∙2H 2O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. Here, we postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Finally,more » additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.« less

Effect of Technetium-99 sources on its retention in low activity waste glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luksic, Steven A.; Kim, Dong-Sang; Um, Wooyong

Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO2∙2H2O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with hexavalent Tc was used. We postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Additional studies are neededmore » to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from glass melt.« less

Effect of Technetium-99 sources on its retention in low activity waste glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luksic, Steven A.; Kim, Dong Sang; Um, Wooyong

Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO 2∙2H 2O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. Here, we postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Finally,more » additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.« less

Effect of Technetium-99 sources on its retention in low activity waste glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luksic, Steven A.; Kim, Dong-Sang; Um, Wooyong

© 2018 Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO 2 ∙2H 2 O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. We postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generallymore » accepted idea. Additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.« less

Effect of Technetium-99 sources on its retention in low activity waste glass

DOE PAGES

Luksic, Steven A.; Kim, Dong-Sang; Um, Wooyong; ...

2018-05-01

© 2018 Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO 2 ∙2H 2 O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. We postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generallymore » accepted idea. Additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.« less

Study on the growth mechanism and optical properties of sputtered lead selenide thin films

NASA Astrophysics Data System (ADS)

Sun, Xigui; Gao, Kewei; Pang, Xiaolu; Yang, Huisheng; Volinsky, Alex A.

2015-11-01

Lead selenide thin films with different microstructure were deposited on Si (1 0 0) substrates using magnetron sputtering at 50 °C, 150 °C and 250 °C, respectively. The crystal structure of the sputtered PbSe thin films varies from amorphous crystalline to columnar grain, and then to double-layer (nano-crystalline layer and columnar grain layer) structure as the deposition temperature increases, which is due to the dominating growth mode of the thin films changes from Frank-van der Merwe (or layer-by-layer) growth mode at 50 °C to Volmer-Weber (or 3D island) growth mode at 150 °C, and then to Stranski-Krastanow (or 3D island-on-wetting-layer) growth mode at 250 °C. The growth mechanism of the sputtered PbSe thin films is mainly dominated by the surface and strain energy contributions. Moreover, the strain energy contribution is more prominent when the deposition temperature is less than 180 °C, while, the surface energy contribution is more prominent when the deposition temperature is higher than 180 °C. The absorption spectra of the sputtered PbSe thin films are in 3.1-5 μm range. Besides, the sputtered PbSe thin film prepared at 250 °C has two different optical band gaps due to its unique double-layer structure. According to the theoretical calculation results, the variation of the band gap with the deposition temperature is determined by the shift of the valence band maximum with the lattice constant.

Intraoperative Injection of Technetium-99m Sulfur Colloid for Sentinel Lymph Node Biopsy in Breast Cancer Patients: A Single Institution Experience.

PubMed

Berrocal, Julian; Saperstein, Lawrence; Grube, Baiba; Horowitz, Nina R; Chagpar, Anees B; Killelea, Brigid K; Lannin, Donald R

2017-01-01

Background . Most institutions require a patient undergoing sentinel lymph node biopsy to go through nuclear medicine prior to surgery to be injected with radioisotope. This study describes the long-term results using intraoperative injection of radioisotope. Methods . Since late 2002, all patients undergoing a sentinel lymph node biopsy at the Yale-New Haven Breast Center underwent intraoperative injection of technetium-99m sulfur colloid. Endpoints included number of sentinel and nonsentinel lymph nodes obtained and number of positive sentinel and nonsentinel lymph nodes. Results . At least one sentinel lymph node was obtained in 2,333 out of 2,338 cases of sentinel node biopsy for an identification rate of 99.8%. The median number of sentinel nodes found was 2 and the mean was 2.33 (range: 1-15). There were 512 cases (21.9%) in which a sentinel node was positive for metastatic carcinoma. Of the patients with a positive sentinel lymph node who underwent axillary dissection, there were 242 cases (54.2%) with no additional positive nonsentinel lymph nodes. Advantages of intraoperative injection included increased comfort for the patient and simplification of scheduling. There were no radiation related complications. Conclusion . Intraoperative injection of technetium-99m sulfur colloid is convenient, effective, safe, and comfortable for the patient.

Intraoperative Injection of Technetium-99m Sulfur Colloid for Sentinel Lymph Node Biopsy in Breast Cancer Patients: A Single Institution Experience

PubMed Central

Berrocal, Julian; Saperstein, Lawrence; Grube, Baiba; Horowitz, Nina R.; Chagpar, Anees B.

2017-01-01

Background. Most institutions require a patient undergoing sentinel lymph node biopsy to go through nuclear medicine prior to surgery to be injected with radioisotope. This study describes the long-term results using intraoperative injection of radioisotope. Methods. Since late 2002, all patients undergoing a sentinel lymph node biopsy at the Yale-New Haven Breast Center underwent intraoperative injection of technetium-99m sulfur colloid. Endpoints included number of sentinel and nonsentinel lymph nodes obtained and number of positive sentinel and nonsentinel lymph nodes. Results. At least one sentinel lymph node was obtained in 2,333 out of 2,338 cases of sentinel node biopsy for an identification rate of 99.8%. The median number of sentinel nodes found was 2 and the mean was 2.33 (range: 1–15). There were 512 cases (21.9%) in which a sentinel node was positive for metastatic carcinoma. Of the patients with a positive sentinel lymph node who underwent axillary dissection, there were 242 cases (54.2%) with no additional positive nonsentinel lymph nodes. Advantages of intraoperative injection included increased comfort for the patient and simplification of scheduling. There were no radiation related complications. Conclusion. Intraoperative injection of technetium-99m sulfur colloid is convenient, effective, safe, and comfortable for the patient. PMID:28492062

Layer Structured Bismuth Selenides of Bi₂Se₃ and Bi₃Se₄ for High Energy and Flexible All-Solid-State Micro-Supercapacitors.

PubMed

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2017-12-20

Bismuth selenides (Bi2Se3 and Bi3Se4), both of which have the layered rhombohedral crystal structure, and found to be useful as electrode materials for supercapacitor application in this work. Bi2Se3 nanoplates as electrode material exhibit much better performance than that of Bi3Se4 nanoparticles in liquid electrolyte system (6 M KOH), which delivers a higher specific capacitance (272.9 F/g) than that of Bi3Se4 (193.6 F/g) at 5 mV/s. This result would may be attributed to that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to its planar quintuple stacked layers (septuple layers for Bi3Se4). For the demand of electronic skin, we used a novel flexible annular interdigital structure electrode applying for all-solid-state micro-supercapacitors (AMSCs). Bi2Se3 AMSCs device delivers a much more excellent supercapacitor performance, exhibits a large stack capacitance 89.5 F/cm3 (Bi3Se4: 79.1 F/cm3) at 20 mV/s, a high energy density 17.9 mWh/cm3 and high power density 18.9 W/cm3. The bismuth selenides also exhibit good cycle stability, retention 95.5% (90.3%) after 1000 c for Bi2Se3 (Bi3Se4). Obviously, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital all-solid-sate supercapacitor. © 2017 IOP Publishing Ltd.

Technetium-99m mercaptoacetyltriglycine clearance: reference values for infants and children.

PubMed

Schofer, O; König, G; Bartels, U; Bockisch, A; Piepenburg, R; Beetz, R; Meyer, G; Hahn, K

1995-11-01

Six hundred and thirty-nine clearance studies performed in children aged 7 days to 19 years utilizing technetium-99m mercaptoacetyltriglycine (MAG 3) were retrospectively analysed. Standardized conditions for the investigation included: parenteral hydration (60 ml/hxm2 body surface) in addition to normal oral fluid intake, weight-related dose of 99mTc-MAG 3 (1 MBq/kg body weight, minimum 15 MBq) and calculation of clearance according to Bubeck et al. Of the 513 children, 169 included in this analysis could be classified as "normal" with regard to their renal function. Normal kidney function was judged by the following criteria: normal GFR for age, normal tubular function (absence of proteinuria and glucosuria), normal renal parenchyma (on ultrasonography, MAG 3 scan and intravenous pyelography), absence of significant obstruction and gross reflux (>grade I), no single kidney and no difference in split renal function >20%. Results showed increasing MAG 3 clearance values for infants during the first months of life, reaching the normal range for older children and adults between 7 and 12 months.

Electrical and optical characteristics of heterojunction devices composed of silicon nanowires and mercury selenide nanoparticle films on flexible plastics.

PubMed

Yeo, Minje; Yun, Junggwon; Kim, Sangsig

2013-09-01

A pn heterojunction device based on p-type silicon (Si) nanowires (NWs) prepared by top-down method and n-type mercury selenide (HgSe) nanoparticles (NPs) synthesized by the colloidal method have been fabricated on a flexible plastic substrate. The synthesized HgSe NPs were analyzed through the effective mass approximation. The characteristics of the heterojunction device were examined and studied with the energy band diagram. The device showed typical diode characteristics with a turn-on voltage of 1.5 V and exhibited a high rectification ratio of 10(3) under relatively low forward bias. Under illumination of 633-nm-wavelength light, the device presented photocurrent efficiency of 117.5 and 20.1 nA/W under forward bias and reverse bias conditions, respectively. Moreover, the photocurrent characteristics of the device have been determined by bending of the plastic substrate upward and downward with strain of 0.8%. Even though the photocurrent efficiency has fluctuations during the bending cycles, the values are roughly maintained for 10(4) bending cycles. This result indicates that the fabricated heterojunction device has the potential to be applied as fundamental elements of flexible nanoelectronics.

The value and throughput of rest Thallium-201/stress Technetium -99m sestamibi dual-isotope myocardial SPECT.

PubMed

Okudan, Berna; Smitherman, Thomas C

2004-06-01

Myocardial perfusion scintigraphy is an established method in cardiology for the diagnosis and evaluation of coronary artery disease (CAD). Thallium-201 and Tc-99m sestamibi myocardial perfusion imaging has been widely accepted as non-invasive diagnostic procedure for detection of CAD, risk stratification and myocardial viability assessment. But, standard Tl-201 redistribution and same day or 2-day rest/stress Tc-99m sestamibi protocols are time-consuming. Hence, the dual isotope rest thallium-201/stress technetium-99m sestamibi gated single-photon emission tomography protocol has gained increasing popularity for these applications. Combining the use of thallium-201 with technetium-99m agents permits optimal image resolution and simultaneous assessment of viability. Dual-isotope imaging may be separate or simultaneous acquisition set-up. The more rapid completion of these studies is appreciated as an advantage by patients, technologists, interpreting and referring physicians, nurses and hospital management. Simultaneous imaging has the potential advantages of precise pixel registration and artifacts, if present, are identical in both thallium and sestamibi, and require only one set of imaging. Also, there are some disadvantages of spillover of activity from the Tc-99m to the Tl-201 window. Fortunately, despite this problem it can be overcome. Separate acquisition dual isotope also has some disadvantages. Difference in defect resolution in attenuation and scatter between T-201 and Tc-99m sestamibi potentially results in interpretation problems. But, studies about cost-effectiveness of dual isotope imaging showed that some selective elimination of the rest studies may decrease the cost of the nuclear procedures and should be considered in the current care health system.

Ultrafast exciton dynamics in cadmium selenide nanocrystals determined by femtosecond fluorescence upconversion spectroscopy

NASA Astrophysics Data System (ADS)

Underwood, David Frederick

Femtosecond fluorescence upconversion spectroscopy is a technique that allows the unambiguous determination of the excited state dynamics of an analyte. Combining this method with the use of tunable laser excitation, the exciton dynamics in semiconducting nanocrystals (NC's) of cadmium selenide (CdSe) have been determined, devoid of the complications arising from more common spectroscopic methods such as pump-probe. The results of this investigation were used to construct a model to fully describe the three-level system comprising of the valence and conduction bands and surface states, which have been calculated by others to lie mid-gap in energy. Smaller NC's showed faster decay components due to increased interaction between the exciton and surface states. The deep trap emission, which has never before been measured by ultrafast fluorescence techniques, shows a rapid rise time (˜2 ps), which is attributed to surface selenium dangling bonds relaxing to the valence band and radiatively combining with the photo-generated hole. The band edge fluorescence decays as the deep trap emission grows in, inherently coupling the two processes. An experiment which measured the dependence of the excitation energy showed that increased energy imparted to the NC's resulted in increased rise times, yielding the timescales for exciton relaxation through the valence and conduction band states to the lowest emitting state. Surface-oxidized and normally-passivated NC's display the same decay dynamics in time but differ in relative amplitude; the latter point agrees with steady-state measurements. The rotational anisotrophy of the NC's was measured and agrees with previous pump-probe data. Upconversion on the red and blue sides of the static fluorescence spectrum showed no discernable differences, which is either and inherent limitation of the experimental apparatus, or the possibility that lower-lying triplet states are populated on a timescale below the instrument resolution.

Technetium-99m-labeled ceftizoxime loaded long-circulating and pH-sensitive liposomes used to identify osteomyelitis.

PubMed

Ferreira, Soraya Maria Zandim Maciel Dias; Domingos, Giselle Pires; Ferreira, Diego dos Santos; Rocha, Talita Guieiro Ribeiro; Serakides, Rogéria; de Faria Rezende, Cleuza Maria; Cardoso, Valbert Nascimento; Fernandes, Simone Odília Antunes; Oliveira, Mônica Cristina

2012-07-15

Osteomyelitis is an infectious disease located in the bone or bone marrow. Long-circulating and pH-sensitive liposomes containing a technetium-99m-labeled antibiotic, ceftizoxime, (SpHL-(99m)Tc-CF) were developed to identify osteomyelitis foci. Biodistribution studies and scintigraphic images of bone infection or non infection-bearing rats that had been treated with these liposomes were performed. A high accumulation in infectious foci and high values in the target-non target ratio could be observed. These results indicate the potential of SpHL-(99m)Tc-CF as a potential agent for the diagnosis of bone infections. Copyright © 2012 Elsevier Ltd. All rights reserved.

Clinical application of calculated split renal volume using computed tomography-based renal volumetry after partial nephrectomy: Correlation with technetium-99m dimercaptosuccinic acid renal scan data.

PubMed

Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo

2017-06-01

To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P < 0.001 and r = 0.94, P < 0.001). The preoperative and postoperative split estimated glomerular filtration rate of the operated kidney showed a moderate correlation with split renal function (r = 0.39, P = 0.004 and r = 0.49, P < 0.001). The correlation between reductions in split renal function and split renal volume of the operated kidney (r = 0.87, P < 0.001) was stronger than that between split renal function and percent reduction in split estimated glomerular filtration rate (r = 0.64, P < 0.001). The split renal volume calculated using computed tomography-based renal volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.

Ion Exchange Distribution Coefficient Tests and Computer Modeling at High Ionic Strength Supporting Technetium Removal Resin Maturation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, Charles A.; Hamm, L. Larry; Smith, Frank G.

2014-12-19

The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and poured into canisters for disposition. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Duemore » to the water solubility properties of pertechnetate and long half-life of 99Tc, effective management of 99Tc is important to the overall success of the Hanford River Protection Project mission. To achieve the full target WTP throughput, additional LAW immobilization capacity is needed, and options are being explored to immobilize the supplemental LAW portion of the tank waste. Removal of 99Tc, followed by off-site disposal, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. To enable an informed decision regarding the viability of technetium removal, further maturation of available technologies is being performed. This report contains results of experimental ion exchange distribution coefficient testing and computer modeling using the resin SuperLig ® 639 a to selectively remove perrhenate from high ionic strength simulated LAW. It is advantageous to operate at higher concentration in order to treat the waste stream without dilution and to minimize the volume of the

Transition from Sign-Reversed to Sign-Preserved Cooper-Pairing Symmetry in Sulfur-Doped Iron Selenide Superconductors.

PubMed

Wang, Qisi; Park, J T; Feng, Yu; Shen, Yao; Hao, Yiqing; Pan, Bingying; Lynn, J W; Ivanov, A; Chi, Songxue; Matsuda, M; Cao, Huibo; Birgeneau, R J; Efremov, D V; Zhao, Jun

2016-05-13

An essential step toward elucidating the mechanism of superconductivity is to determine the sign or phase of the superconducting order parameter, as it is closely related to the pairing interaction. In conventional superconductors, the electron-phonon interaction induces attraction between electrons near the Fermi energy and results in a sign-preserved s-wave pairing. For high-temperature superconductors, including cuprates and iron-based superconductors, prevalent weak coupling theories suggest that the electron pairing is mediated by spin fluctuations which lead to repulsive interactions, and therefore that a sign-reversed pairing with an s_{±} or d-wave symmetry is favored. Here, by using magnetic neutron scattering, a phase sensitive probe of the superconducting gap, we report the observation of a transition from the sign-reversed to sign-preserved Cooper-pairing symmetry with insignificant changes in T_{c} in the S-doped iron selenide superconductors K_{x}Fe_{2-y}(Se_{1-z}S_{z})_{2}. We show that a rather sharp magnetic resonant mode well below the superconducting gap (2Δ) in the undoped sample (z=0) is replaced by a broad hump structure above 2Δ under 50% S doping. These results cannot be readily explained by simple spin fluctuation-exchange pairing theories and, therefore, multiple pairing channels are required to describe superconductivity in this system. Our findings may also yield a simple explanation for the sometimes contradictory data on the sign of the superconducting order parameter in iron-based materials.

Technetium Getters to Improve Cast Stone Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey

2015-10-15

The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most tomore » the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.« less

Aspects of a Distinct Cytotoxicity of Selenium Salts and Organic Selenides in Living Cells with Possible Implications for Drug Design.

PubMed

Estevam, Ethiene Castellucci; Witek, Karolina; Faulstich, Lisa; Nasim, Muhammad Jawad; Latacz, Gniewomir; Domínguez-Álvarez, Enrique; Kieć-Kononowicz, Katarzyna; Demasi, Marilene; Handzlik, Jadwiga; Jacob, Claus

2015-07-31

Selenium is traditionally considered as an antioxidant element and selenium compounds are often discussed in the context of chemoprevention and therapy. Recent studies, however, have revealed a rather more colorful and diverse biological action of selenium-based compounds, including the modulation of the intracellular redox homeostasis and an often selective interference with regulatory cellular pathways. Our basic activity and mode of action studies with simple selenium and tellurium salts in different strains of Staphylococcus aureus (MRSA) and Saccharomyces cerevisiae indicate that such compounds are sometimes not particularly toxic on their own, yet enhance the antibacterial potential of known antibiotics, possibly via the bioreductive formation of insoluble elemental deposits. Whilst the selenium and tellurium compounds tested do not necessarily act via the generation of Reactive Oxygen Species (ROS), they seem to interfere with various cellular pathways, including a possible inhibition of the proteasome and hindrance of DNA repair. Here, organic selenides are considerably more active compared to simple salts. The interference of selenium (and tellurium) compounds with multiple targets could provide new avenues for the development of effective antibiotic and anticancer agents which may go well beyond the traditional notion of selenium as a simple antioxidant.

Measurement of technetium-99 in Marshall Islands soil samples by ICP-MS

PubMed

Tagami; Uchida; Hamilton; Robison

2000-07-01

Extraction techniques for recovery of technetium-99 (99Tc) for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (MI) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for 99Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the 99Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The 99Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq g(-1) dry weight (dw). The limit of detection for 99Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq g(-1) dw under standard operating conditions.

On the absence of young white dwarf companions to five technetium stars

NASA Technical Reports Server (NTRS)

Smith, Verne V.; Lambert, David L.

1987-01-01

A search for hot companions to five stars of type MS and S has been carried out using the IUE satellite. No hot companions were detected for the MS stars HR 85, 4647, 6702, and 8062, and the S star HR 8714. Limits on the luminosities of possible white dwarf companions provide lower limits of 2-5x10 to the 8th yr to the ages of any degenerate companions. All five stars exhibit strong Tc I lines, and the presence of technetium, with a half-life of 2.1x10 to the 5th yr, signifies recent nucleosynthesis. The limits on the ages of possible white dwarf companions that are equal to or greater than 1000 half-lives of Tc exclude the possibility that the s-process elemental enhancement seen in these MS and S stars resulted from mass transfer from a more highly evolved companion (as is probably the mechanism by which barium stars are created). These MS and S stars represent a sample of true thermally pulsing asymptotic giant-branch stars.

Differences between the macroscopic and tracer level chemistry of rhenium and technetium: contrasting cage isomerisation behaviour of Re(I) and Tc(I) carborane complexes.

PubMed

Armstrong, Andrea F; Valliant, John F

2010-09-21

Carboranes form stable complexes with the [M(CO)(3)](+) (M = (99m)Tc, Re) core and are viable ligands for the development of targeted radiopharmaceuticals. (99m)Tc-carborane complexes were found to exhibit substantially different 1,2-->1,7 cage isomerisation behaviour than their Re counterparts, challenging the validity of the routine use of rhenium as a surrogate for the development of technetium-99m based molecular imaging agents.

Synthesis and characterization of Cadmium selenide nanoparticles loaded on activated carbon and its efficient application for removal of Muroxide from aqueous solution

NASA Astrophysics Data System (ADS)

Ghaedi, M.; Amirabad, S. Zamani; Marahel, F.; Nasiri Kokhdan, S.; Sahraei, R.; Nosrati, M.; Daneshfar, A.

2011-12-01

In the first, Cadmium selenide Nanoparticle loaded on activated carbon (CdSe-NP-AC) has been synthesized and characterized by different techniques including XRD and SEM. Then, this new adsorbent successfully has been applied for the removal of muroxide (MO) from aqueous solution in batch studies, while the effect of various experimental parameters like initial pH (pH 0), contact time, amount of (CdSe-NP-AC) and initial MO concentration ( C0) on its removal percentage was examined by one at a time optimization method. It was found following optimization of variable, the adsorption of MO onto (CdSe-NP-AC) followed pseudo-second-order kinetics and show Tempkin and Langmuir models for interpretation of experimental data. It was observed that by increasing the temperature the removal percentage was improved and the positive change in entropy (Δ S°) and heat of adsorption (Δ H°) show the endothermic nature of process, while the high negative value in Gibbs free energy change (Δ G°) indicates the feasible nature of adsorption process.

Identification of Warthin tumor: magnetic resonance imaging versus salivary scintigraphy with technetium-99m pertechnetate.

PubMed

Motoori, Ken; Ueda, Takuya; Uchida, Yoshitaka; Chazono, Hideaki; Suzuki, Homare; Ito, Hisao

2005-01-01

The aim of this study was to evaluate the accuracy of technetium-99m (Tc-99m) pertechnetate scintigraphy and magnetic resonance (MR) imaging in the diagnosis of Warthin tumor. Sixteen cases of Warthin tumor and 17 cases of non-Warthin tumor were examined by Tc-99m pertechnetate scintigraphy with lemon juice stimulation and MR imaging, including T1-weighted, T2-weighted, short inversion time inversion recovery, diffusion-weighted, and contrast-enhanced dynamic images. We used the receiver operating characteristic (ROC) curve to evaluate diagnostic accuracy. The mean area under the ROC curves of MR imaging in the diagnosis of Warthin tumor (0.97) was higher than that of Tc-99m pertechnetate scintigraphy (0.88). Magnetic resonance imaging is more useful in the evaluation of Warthin tumor than Tc-99m pertechnetate scintigraphy.

New quaternary thallium indium germanium selenide TlInGe2Se6: Crystal and electronic structure

NASA Astrophysics Data System (ADS)

Khyzhun, O. Y.; Parasyuk, O. V.; Tsisar, O. V.; Piskach, L. V.; Myronchuk, G. L.; Levytskyy, V. O.; Babizhetskyy, V. S.

2017-10-01

Crystal structure of a novel quaternary thallium indium germanium selenide TlInGe2Se6 was investigated by means of powder X-ray diffraction method. It was determined that the compound crystallizes in the trigonal space group R3 with the unit cell parameters a = 10.1798(2) Å, c = 9.2872(3) Å. The relationship with similar structures was discussed. The as-synthesized TlInGe2Se6 ingot was tested with X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). In particular, the XPS valence-band and core-level spectra were recorded for initial and Ar+ ion-bombarded surfaces of the sample under consideration. The XPS data allow for statement that the TlInGe2Se6 surface is rigid with respect to Ar+ ion-bombardment. Particularly, Ar+ ion-bombardment (3.0 keV, 5 min duration, ion current density fixed at 14 μA/cm2) did not cause substantial modifications of stoichiometry in topmost surface layers. Furthermore, comparison on a common energy scale of the XES Se Kβ2 and Ge Kβ2 bands and the XPS valence-band spectrum reveals that the principal contributions of the Se 4p and Ge 4p states occur in the upper and central portions of the valence band of TlInGe2Se6, respectively, with also their substantial contributions in other portions of the band. The bandgap energy of TlInGe2Se6 at the level of αg=103 cm-1 is equal to 2.38 eV at room temperature.

Enterogastroesophageal reflux detected on 99m-technetium sestamibi cardiac imaging as a cause of chest pain

PubMed Central

Erdoğan, Zeynep; Silov, Güler; Özdal, Ayşegül; Turhal, Özgül

2013-01-01

Myocardial perfusion imaging (MPI) with technetium-99m sestamibi (Tc-99m MIBI) is considered a diagnostic technique that is widely used for the investigation of suspected coronary artery disease. Incidental inspection of an extracardiac activity is indirect, but important marker, which can identify a potentially treatable non-coronary cause for chest pain that may mimic cardiac symptoms. Here, we present an illustrative case in which significant enterogastroesophageal reflux of Tc-99m MIBI occurred during the cardiac imaging following prompt hepatobiliary clearance. Because, there was normal myocardial perfusion on MPI, presence of gastroesophageal reflux (GER) on GER scintigraphy and detection of mild inflammation with pathologically confirmed hyperplastic polyp by endoscopy, in view of the above findings we concluded that the probable cause of chest pain was reflux. PMID:24019679

A tracer dose of technetium-99m-labeled liposomes can estimate the effect of hyperthermia on intratumoral doxil extravasation.

PubMed

Kleiter, Miriam M; Yu, Daohai; Mohammadian, Lenore A; Niehaus, Nelsen; Spasojevic, Ivan; Sanders, Linda; Viglianti, Benjamin L; Yarmolenko, Pavel S; Hauck, Marlene; Petry, Neil A; Wong, Terence Z; Dewhirst, Mark W; Thrall, Donald E

2006-11-15

A noninvasive method to monitor intratumoral Doxil delivery in individual patients during targeted tumor therapy is important to predict treatment response. The purpose of this study was to determine if a small tracer dose of technetium-99m (99mTc)-labeled liposomes could be used to quantify the effect of local hyperthermia on intratumoral Doxil extravasation. Experiments were carried out in a rat fibrosarcoma model with transplanted thigh tumors. Liposomes of approximately same size and composition as Doxil were radiolabeled using [technetium-99m (99mTc)]exametazime. Eight treatment groups received either Doxil, a tracer dose or a large dose of 99mTc-labeled liposomes, or a combination of tracer and Doxil, with or without hyperthermia. This design was chosen to assure that coadministration of both liposomal formulations did not influence their intratumoral distribution. Hyperthermia was done for 45 minutes. Scintigraphic images were obtained at 5 and 18 hours. At 18 hours, tumors were removed and gamma counts as well as doxorubicin concentrations were measured. Intratumoral extravasation of the 99mTc-labeled tracer could be imaged scintigraphically under normothermic and hyperthermic conditions. The thermal enhancement ratio was slightly higher for radiolabeled liposomes than for doxorubicin concentration. However, there was a significant positive correlation of intratumoral doxorubicin concentration and intratumoral uptake of the radiolabeled tracer (expressed as percentage of the injected dose per gram of tissue). Coadministration of radiolabeled liposomes did not negatively influence the amount of drug delivered with Doxil. The use of a radiolabeled tracer has potential value to monitor drug delivery and estimate the effect of an intervention aimed to increase liposomal accumulation, such as local hyperthermia.

In Situ Determination of Bisphenol A in Beverage Using a Molybdenum Selenide/Reduced Graphene Oxide Nanoparticle Composite Modified Glassy Carbon Electrode.

PubMed

Shi, Rongguang; Liang, Jing; Zhao, Zongshan; Liu, Yi; Liu, Aifeng

2018-05-22

Due to the endocrine disturbing effects of bisphenol A (BPA) on organisms, rapid detection has become one of the most important techniques for monitoring its levels in the aqueous solutions associated with plastics and human beings. In this paper, a glassy carbon electrode (GCE) modified with molybdenum selenide/reduced graphene oxide (MoSe₂/rGO) was fabricated for in situ determination of bisphenol A in several beverages. The surface area of the electrode dramatically increases due to the existence of ultra-thin nanosheets in a flower-like structure of MoSe₂. Adding phosphotungstic acid in the electrolyte can significantly enhance the repeatability (RSD = 0.4%) and reproducibility (RSD = 2.2%) of the electrode. Under the optimized condition (pH = 6.5), the linear range of BPA was from 0.1 μM⁻100 μM and the detection limit was 0.015 μM (S/ N = 3). When using the as-prepared electrode for analyzing BPA in beverage samples without any pretreatments, the recoveries ranged from 98⁻107%, and the concentrations were from below the detection limit to 1.7 μM, indicating its potential prospect for routine analysis of BPA.

A solvent-extraction module for cyclotron production of high-purity technetium-99m.

PubMed

Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Uccelli, Licia; Pasquali, Micòl; Duatti, Adriano; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Esposito, Juan

2016-12-01

The design and fabrication of a fully-automated, remotely controlled module for the extraction and purification of technetium-99m (Tc-99m), produced by proton bombardment of enriched Mo-100 molybdenum metallic targets in a low-energy medical cyclotron, is here described. After dissolution of the irradiated solid target in hydrogen peroxide, Tc-99m was obtained under the chemical form of 99m TcO 4 - , in high radionuclidic and radiochemical purity, by solvent extraction with methyl ethyl ketone (MEK). The extraction process was accomplished inside a glass column-shaped vial especially designed to allow for an easy automation of the whole procedure. Recovery yields were always >90% of the loaded activity. The final pertechnetate saline solution Na 99m TcO 4 , purified using the automated module here described, is within the Pharmacopoeia quality control parameters and is therefore a valid alternative to generator-produced 99m Tc. The resulting automated module is cost-effective and easily replicable for in-house production of high-purity Tc-99m by cyclotrons. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermoelectric materials and methods for synthesis thereof

DOEpatents

Ren, Zhifeng; Zhang, Qinyong; Zhang, Qian; Chen, Gang

2015-08-04

Materials having improved thermoelectric properties are disclosed. In some embodiments, lead telluride/selenide based materials with improved figure of merit and mechanical properties are disclosed. In some embodiments, the lead telluride/selenide based materials of the present disclosure are p-type thermoelectric materials formed by adding sodium (Na), silicon (Si) or both to thallium doped lead telluride materials. In some embodiments, the lead telluride/selenide based materials are formed by doping lead telluride/selenides with potassium.

Technetium incorporation into goethite (α-FeOOH): An atomic-scale investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Frances N.; Taylor, Christopher D.; Um, Wooyong

2015-11-17

During the processing of low-activity radioactive waste to generate solid waste forms (e.g., glass), technetium-99 (Tc) is of concern because of its volatility. A variety of materials are under consideration to capture Tc from waste streams, including the iron oxyhydroxide, goethite (α-FeOOH), which was experimentally shown to sequester Tc(IV). This material could ultimately be incorporated into glass or other low-temperature waste form matrices. However, questions remain regarding the incorporation mechanism for Tc(IV) in goethite, which has implications for predicting the long-term stability of Tc in waste forms under changing conditions. Here, quantum-mechanical calculations were used to evaluate the energy ofmore » five different charge-compensated Tc(IV) incorporation scenarios in goethite. The two most stable incorporation mechanisms involve direct substitution of Tc(IV) onto Fe(III) lattice sites and charge balancing either by removing one nearby H+ (i.e., within 5 Å), or by creating an Fe(III) vacancy when substituting 3 Tc(IV) for 4 Fe(III), with the former being preferred over the latter relative to gas-phase ions. When corrections for hydrated references phases are applied, the Fe(III)-vacancy mechanism becomes more energetically competitive. Calculated incorporation energies and optimized bond-lengths are presented. Proton movement is observed to satisfy under-coordinated bonds surrounding vacancies in the goethite structure.« less

Guava extract (Psidium guajava) alters the labelling of blood constituents with technetium-99m.

PubMed

Abreu, P R C; Almeida, M C; Bernardo, R M; Bernardo, L C; Brito, L C; Garcia, E A C; Fonseca, A S; Bernardo-Filho, M

2006-06-01

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m ((99m)Tc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with (99m)Tc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with (99m)Tc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with (99m)Tc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with (99m)Tc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.

Guava extract (Psidium guajava) alters the labelling of blood constituents with technetium-99m*

PubMed Central

Abreu, P.R.C.; Almeida, M.C.; Bernardo, R.M.; Bernardo, L.C.; Brito, L.C.; Garcia, E.A.C.; Fonseca, A.S.; Bernardo-Filho, M.

2006-01-01

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract. PMID:16691636

Physical and biophysical assessment of highly fluorescent, magnetic quantum dots of a wurtzite-phase manganese selenide system

NASA Astrophysics Data System (ADS)

Sarma, Runjun; Das, Queen; Hussain, Anowar; Ramteke, Anand; Choudhury, Amarjyoti; Mohanta, Dambarudhar

2014-07-01

Combining fluorescence and magnetic features in a non-iron based, select type of quantum dots (QDs) can have immense value in cellular imaging, tagging and other nano-bio interface applications, including targeted drug delivery. Herein, we report on the colloidal synthesis and physical and biophysical assessment of wurtzite-type manganese selenide (MnSe) QDs in cell culture media. Aiming to provide a suitable colloidal system of biological relevance, different concentrations of reactants and ligands (e.g., thioglycolic acid, TGA) have been considered. The average size of the QDs is ˜7 nm, which exhibited a quantum yield of ˜75% as compared to rhodamine 6 G dye®. As revealed from time-resolved photoluminescence (TR-PL) response, the near band edge emission followed a bi-exponential decay feature with characteristic times of ˜0.64 ns and 3.04 ns. At room temperature, the QDs were found to exhibit paramagnetic features with coercivity and remanence impelled by TGA concentrations. With BSA as a dispersing agent, the QDs showed an improved optical stability in Dulbecco’s Modified Eagle Media® (DMEM) and Minimum Essential Media® (MEM), as compared to the Roswell Park Memorial Institute® (RPMI-1640) media. Finally, the cell viability of lymphocytes was found to be strongly influenced by the concentration of MnSe QDs, and had a safe limit upto 0.5 μM. With BSA inclusion in cell media, the cellular uptake of MnSe QDs was observed to be more prominent, as revealed from fluorescence imaging. The fabrication of water soluble, nontoxic MnSe QDs would open up an alternative strategy in nanobiotechnology, while preserving their luminescent and magnetic properties intact.

Lead-Sulfide-Selenide Quantum Dots and Gold-Copper Alloy Nanoparticles Augment the Light-Harvesting Ability of Solar Cells.

PubMed

Das, Aparajita; Deepa, Melepurath; Ghosal, Partha

2017-04-05

Lead-sulfide-selenide (PbSSe) quantum dots (QDs) and gold-copper (AuCu) alloy nanoparticles (NPs) were incorporated into a cadmium sulfide (CdS)/titanium oxide (TiO 2 ) photoanode for the first time to achieve enhanced conversion of solar energy into electricity. PbSSe QDs with a band gap of 1.02 eV extend the light-harvesting range of the photoanode from the visible region to the near-infrared region. The conduction band (CB) edge of the PbSSe QDs is wedged between the CBs of TiO 2 and CdS; this additional level coupled with the good electrical conductivity of the dots facilitate charge transport and collection, and a high power conversion efficiency (PCE) of 4.44 % is achieved for the champion cell with the TiO 2 /PbSSe/CdS electrode. Upon including AuCu alloy NPs in the QD-sensitized electrodes, light absorption is enhance by plasmonic and light-scattering effects and also by the injection of hot electrons to the CBs of the QDs. Comparison of the incident photon-to-current conversion efficiency enhancement factors in addition to fluorescence decay and impedance studies reveal that the PbSSe QDs and AuCu alloy NPs promote charge injection to the current collector and increase the photogenerated charges produced, which thus enables the TiO 2 /PbSSe/CdS/AuCu cell to deliver the highest PCE of 5.26 % among all the various photoanode compositions used. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Value of positive myocardial technetium-99m-pyrophosphate scintigraphy in the noninvasive diagnosis of cardiac amyloidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wizenberg, T.A.; Muz, J.; Sohn, Y.H.

1982-04-01

Ten consecutive patients with tissue-proven amyloidosis, seven of whom presented with congestive heart failure, were found to exhibit intense diffuse uptake of technetium-99m-pyrophosphate (Tc-99m-PYP) on cardiac radionuclide imaging. The patients exhibited echocardiographic and systolic time interval abnormalities suggesting combined restrictive and congestive cardiomyopathic changes. On M-mode echocardiograms, there was symmetrically increased thickness of the interventricular septum and left ventricular (LV) posterior wall in diastole (10 of 10), decreased fractional shortening of the LV minor axis diameter in systole (eight of nine), and decreased percent thickening of the LV minor axis diameter in systole (eight of nine) and LV posterior wallmore » (10 of 10) in systole. Three patients demonstrated enlarged LV end-diastolic diameter. All 10 patients had abnormal PEP/LVET and eight had shortened LVETI. When combined with noninvasive tests of LV performance, positive myocardial pyrophosphate (PYP) scanning provides a new and useful adjunct in the diagnosis of amyloid heart disease.« less

Residence time effects on technetium reduction in slag-based cementitious materials.

PubMed

Arai, Yuji; Powell, Brian A; Kaplan, D I

2018-01-15

A long-term disposal of technetium-99 ( 99 Tc) has been considered in a type of cementitious formulation, slag-based grout, at the U.S. Department of Energy, Savannah River Site, Aiken SC, U.S.A. Blast furnace slag, which contains S and Fe electron donors, has been used in a mixture with fly ash, and Portland cement to immobilize 99 Tc(VII)O 4 - (aq) in low level radioactive waste via reductive precipitation reaction. However the long-term stability of Tc(IV) species is not clearly understood as oxygen gradually diffuses into the solid structure. In this study, aging effects of Tc speciation were investigated as a function of depth (<2.5cm) in slag-based grout using X-ray absorption spectroscopy. All of Fe(II) in solids was oxidized to Fe(III) after 117d. However, elemental S, sulfide, and sulfoxide persists at the 0-8mm depths even after 485d, suggesting the presence of a reduced zone below the surface few millimeters. Pertechnetate was successfully reduced to Tc(IV) after 29d. Distorted hydrolyzed Tc(IV) octahedral molecules were partially sulfidized and or polymerized at all depths (0-8mm) and were stable in 485d aged sample. The results of this study suggest that variable S species contribute to stabilize the partially sulfidized Tc(IV) species in aged slag-based grout. Copyright © 2017 Elsevier B.V. All rights reserved.

Rhenium and technetium tricarbonyl, {M(CO)3} (+) (M = Tc, Re), binding to mammalian metallothioneins: new insights into chemical and radiopharmaceutical implications.

PubMed

Lecina, Joan; Palacios, Òscar; Atrian, Sílvia; Capdevila, Mercè; Suades, Joan

2015-04-01

This paper deals with the binding of the four mammalian metallothioneins (MTs) to the organometallic metal fragment {fac-M(CO)3}(+) (M = (99)Tc, Re), which is highly promising for the preparation of second-generation radiopharmaceuticals. The study of the transmetallation reaction between zinc and rhenium in Zn7-MT1 by means of UV-vis and CD spectroscopy demonstrated the incorporation of the {fac-Re(CO)3}(+) fragment to the MTs. This reaction should be performed at 70 °C to accelerate the reaction rate, a result that is consistent with the reported reactivity of the rhenium fragment. ESI-TOF MS demonstrated the formation of mixed-metal species as Zn6,{Re(CO)3}-MT, Zn6,{Re(CO)3}2-MT, and Zn5,{Re(CO)3}3-MT, as well as the different reactivity of the four MT isoforms. Hence, Zn-MT3 showed the highest reactivity, in agreement with its high Cu-thionein character, whereas Zn-MT2 exhibited the lowest reactivity, in line with its high Zn-thionein character. The reactivity of the Zn-loaded forms of MT1 and MT4 is intermediate between those of MT3 and MT2. The study of the binding of the {fac-(99)Tc(CO)3}(+) fragment to MTs showed a significant and very interesting different reactivity in relation to rhenium. The transmetallation reaction is much more effective with technetium than with rhenium and significant amounts of mixed Zn x ,{(99)Tc(CO)3} y -MT species were formed with the four MT isoforms whereas only MT3 rendered similar amounts of rhenium derivatives. The results obtained in this study support the possible use of technetium for labelling mammalian metallothioneins and also for possible radiopharmaceutical applications.

Microbial Transformations of Selenium

PubMed Central

Doran, J. W.; Alexander, M.

1977-01-01

Resting cell suspensions of a strain of Corynebacterium isolated from soil formed dimethyl selenide from selenate, selenite, elemental selenium, selenomethionine, selenocystine, and methaneseleninate. Extracts of the bacterium catalyzed the production of dimethyl selenide from selenite, elemental selenium, and methaneseleninate, and methylation of the inorganic Se compounds was enhanced by S-adenosylmethionine. Neither trimethylselenonium nor methaneselenonate was metabolized by the Corynebacterium. Resting cell suspensions of a methionine-utilizing pseudomonad converted selenomethionine to dimethyl diselenide. Six of 10 microorganisms able to grow on cystine used selenocystine as a sole source of carbon and formed elemental selenium, and one of the isolates, a pseudomonad, was found also to produce selenide. Soil enrichments converted trimethylselenonium to dimethyl selenide. Bacteria capable of utilizing trimethylselenonium, dimethyl selenide, and dimethyl diselenide as carbon sources were isolated from soil. PMID:16345188

[Improvement in nuclear medicine diagnosis of kidney function using 99m technetium mercaptoacetyltriglycine (MAG3)].

PubMed

Erpenbach, K; Ebert, A; Wieler, H

1991-03-01

Renal scintigraphy and clearance measurement are indispensable in nephro-urologic disorders. A continuous series of 103 sequential scintigraphies and clearance measurements were performed with the new technetium-labelled agent MAG3 (Gamma-kamera, Phillips Tomo Diagnost) and 131I-orthohippuric acid (OIH) using the Oberhausen method (Nucleopan, Siemens). The time-activity curves obtained with the two radionuclides agreed exactly. Reaching a tubular excretion rate of nearly 90%, the clearance of MAG3 differed by no more than 6% from the OIH clearance in 95% of the cases. The factor between clearances of the two radionuclides was determined by means of a commercially available software according to the Oberhausen method and amounted to 0.59 +/- 0.09. The favorable physical properties and high activity of MAG3 permit exact examination of tubular function and better assessment of renal morphology than hippuran-labelled radionuclides. The low radiation dose combined with a better spatial resolution, especially, the constant availability in a nuclear medicine department should give the preference to MAG3.

Evolution of technetium-99m-HMPAO SPECT and brain mapping in a patient presenting with echolalia and palilalia.

PubMed

Dierckx, R A; Saerens, J; De Deyn, P P; Verslegers, W; Marien, P; Vandevivere, J

1991-08-01

A 78-yr-old woman presented with transient echolalia and palilalia. She had suffered from Parkinson's disease for 2 yr. Routine laboratory examination showed hypotonic hyponatremia, but was otherwise unremarkable. Brain mapping revealed a bifrontal delta focus, more pronounced on the right. Single photon emission computed tomography (SPECT) of the brain with technetium-99m labeled d,l hexamethylpropylene-amine oxime (99mTc-HMPAO), performed during the acute episode showed relative frontoparietal hypoactivity. Brain mapping performed after disappearance of the echolalia and palilalia, which persisted only for 1 day, was normal. By contrast, SPECT findings persisted for more than 3 wk. Features of particular interest in the presented patient are the extensive defects seen on brain SPECT despite the absence of morphologic lesions, the congruent electrophysiologic changes and their temporal relationship with the clinical evolution.

Growth Mechanism of Nanowires: Binary and Ternary Chalcogenides

NASA Technical Reports Server (NTRS)

Singh, N. B.; Coriell, S. R.; Su, Ching-Hua; Hopkins, R. H.; Arnold, B.; Choa, Fow-Sen; Cullum, Brian

2016-01-01

Semiconductor nanowires exhibit very exciting optical and electrical properties including high transparency and a several order of magnitude better photocurrent than thin film and bulk materials. We present here the mechanism of nanowire growth from the melt-liquid-vapor medium. We describe preliminary results of binary and ternary selenide materials in light of recent theories. Experiments were performed with lead selenide and thallium arsenic selenide systems which are multifunctional material and have been used for detectors, acousto-optical, nonlinear and radiation detection applications. We observed that small units of nanocubes and elongated nanoparticles arrange and rearrange at moderate melt undercooling to form the building block of a nanowire. Since we avoided the catalyst, we observed self-nucleation and uncontrolled growth of wires from different places. Growth of lead selenide nanowires was performed by physical vapor transport method and thallium arsenic selenide nanowire by vapor-liquid-solid (VLS) method. In some cases very long wires (>mm) are formed. To achieve this goal experiments were performed to create situation where nanowires grew on the surface of solid thallium arsenic selenide itself.

Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

PubMed

Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

2016-02-01

Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. Copyright © 2015 Elsevier B.V. All rights reserved.

Theoretical investigation of electronic states and spectroscopic properties of tellurium selenide molecule employing relativistic effective core potentials.

PubMed

Chattopadhyaya, Surya; Nath, Abhijit; Das, Kalyan Kumar

2014-04-24

Ab initio based relativistic configuration interaction calculations have been performed to study the electronic states and spectroscopic properties of tellurium selenide (TeSe) - the heaviest heteronuclear diatomic group 16-16 molecule. Potential energy curves of several spin-excluded (Λ-S) electronic states of TeSe have been constructed and spectroscopic constants of low-lying bound Λ-S states within 3.85 eV are reported in the first stage of calculations. The X(3)Σ(-), a(1)Δ and b(1)Σ(+) are found as the ground, first excited and second excited state, respectively, at the Λ-S level and all these three states are mainly dominated by …π(4)π(*2) configuration. The computed ground state dissociation energy is in very good agreement with the experimental results. In the next stage of calculations, effects of spin-orbit coupling on the potential energy curves and spectroscopic properties of the species are investigated in details and compared with the existing experimental results. After inclusion of spin-orbit coupling the X(3)(1)Σ(-)(0(+)) is found as the ground-state spin component of TeSe. The computed spin-orbit splitting between two components of X(3)Σ(-) state is 1285 cm(-1). Also, significant amount of spin-orbit splitting are found between spin-orbit components (Ω-components) of several other excited states. Transition moments of some important spin-allowed and spin-forbidden transitions are calculated from configuration interaction wave functions. The spin-allowed transition B(3)Σ(-)-X(3)Σ(-) and spin-forbidden transition b(1)Σ(+)(0(+))-X(3)(1)Σ(-)(0(+)) are found to be the strongest in their respective categories. Electric dipole moments of all the bound Λ-S states along with those of the two Ω-components of X(3)Σ(-) are also calculated in the present study. Copyright © 2014 Elsevier B.V. All rights reserved.

Composite-Nanoparticles Thermal History Sensors

DTIC Science & Technology

2014-05-01

al. Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions Fig. 5. SEM image of PbTe solid nano- and micro-cubes...Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of PbSe microflowers, a similar pro...R C H A R TIC LE Poudel et al. Lead Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of

Rhenium and technetium tricarbonyl complexes of 1,4-Substituted pyridyl-1,2,3-triazole bidentate 'click' ligands conjugated to a targeting RGD peptide.

PubMed

Connell, Timothy U; Hayne, David J; Ackermann, Uwe; Tochon-Danguy, Henri J; White, Jonathan M; Donnelly, Paul S

2014-04-01

New 1,4-substituted pyridyl-1,2,3-triazole ligands with pendent phenyl isothiocyanate functional groups linked to the heterocycle through a short methylene or longer polyethylene glycol spacers were prepared and conjugated to a peptide containing the arginine-glycine-aspartic acid peptide motif. Rhenium and technetium carbonyl complexes, [M(CO)3 L(x) (py)](+) (where M = Re(I) or (99m) Tc(I) ; L(x)  = 1,4-substituted pyridyl-1,2,3-triazole ligands and py = pyridine) were prepared. One rhenium complex has been characterized by X-ray crystallography, and the luminescent properties of [M(CO)3 L(x) (py)](+) are reported. Copyright © 2013 John Wiley & Sons, Ltd.

Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region

NASA Astrophysics Data System (ADS)

Ikeda, Yuji; Kobayashi, Naoto; Kondo, Sohei; Yasui, Chikako; Kuzmenko, Paul J.; Tokoro, Hitoshi; Terada, Hiroshi

2009-08-01

We measure the internal attenuation of bulk crystals of chemical vapor deposition zinc selenide (CVD-ZnS), chemical vapor deposition zinc sulfide (CVD-ZnSe), Si, and GaAs in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with the smallest internal attenuation of αatt=0.01 to 0.03 cm-1 among the major candidates. The measured attenuation is roughly in proportion to λ-2, suggesting it is dominated by bulk scattering due to the polycrystalline grains rather than by absorption. The total transmittance in the immersion grating is estimated to be at least >80%, even for the spectral resolution of R=300,000. Two potential problems, the scattered light by the bulk material and the degradation of the spectral resolution due to the gradient illumination in the diffracted beam, are investigated and found to be negligible for usual astronomical applications. Since the remaining problem, the difficulty of cutting grooves on CVD-ZnS and CVD-ZnSe, has recently been overcome by the nanoprecision fly-cutting technique, ZnS and ZnSe immersion gratings for astronomy can be technically realized.

A prospective evaluation of preoperative localization by technetium-99m sestamibi scintigraphy and ultrasonography in primary hyperparathyroidism.

PubMed

Lo, Chung-Yau; Lang, Brian H; Chan, W F; Kung, Annie W C; Lam, Karen S L

2007-02-01

Ultrasonography (USG) and technetium-99m sestamibi (MIBI) scintigraphy are commonly used imaging modalities in the era of minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism (pHPT). However, their relative importance and actual contribution to MIP have not been prospectively assessed. A total of 100 consecutive pHPT patients planning for MIP were recruited. Both USG and MIBI findings were correlated with intraoperative findings and postoperative outcome. Clinicopathologic factors were examined for potential association with a correct localizing result. Thirty men and 70 women (age range 13 to 93 years [median 55.5]) were included in the study. The final pathology included 98 patients with solitary adenoma and 2 patients with multiglandular disease. The sensitivities, accuracies, and positive predicted values for USG and MIBI alone were 57% vs 89%, 56% vs 85%, and 97% vs 94%, respectively. Correctly localized adenomas were significantly heavier than incorrectly localized ones. MIBI is preferred over USG in pHPT patients planning for MIP. Weight of adenoma appeared to be the only clinicopathologic factor determining localization accuracy.

Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

NASA Technical Reports Server (NTRS)

Patterson, James D.; Li, Wei-Gang

1995-01-01

The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

New Antimony Selenide/Nickel Oxide Photocathode Boosts the Efficiency of Graphene Quantum-Dot Co-Sensitized Solar Cells.

PubMed

Kolay, Ankita; Kokal, Ramesh K; Kalluri, Ankarao; Macwan, Isaac; Patra, Prabir K; Ghosal, Partha; Deepa, Melepurath

2017-10-11

A novel assembly of a photocathode and a photoanode is investigated to explore their complementary effects in enhancing the photovoltaic performance of a quantum-dot solar cell (QDSC). While p-type nickel oxide (NiO) has been used previously, antimony selenide (Sb 2 Se 3 ) has not been used in a QDSC, especially as a component of a counter electrode (CE) architecture that doubles as the photocathode. Here, near-infrared (NIR) light-absorbing Sb 2 Se 3 nanoparticles (NPs) coated over electrodeposited NiO nanofibers on a carbon (C) fabric substrate was employed as the highly efficient photocathode. Quasi-spherical Sb 2 Se 3 NPs, with a band gap of 1.13 eV, upon illumination, release photoexcited electrons in addition to other charge carriers at the CE to further enhance the reduction of the oxidized polysulfide. The p-type conducting behavior of Sb 2 Se 3 , coupled with a work function at 4.63 eV, also facilitates electron injection to polysulfide. The effect of graphene quantum dots (GQDs) as co-sensitizers as well as electron conduits is also investigated in which a TiO 2 /CdS/GQDs photoanode structure in combination with a C-fabric CE delivered a power-conversion efficiency (PCE) of 5.28%, which is a vast improvement over the 4.23% that is obtained by using a TiO 2 /CdS photoanode (without GQDs) with the same CE. GQDs, due to a superior conductance, impact efficiency more than Sb 2 Se 3 NPs do. The best PCE of a TiO 2 /CdS/GQDs-nS 2- /S n 2- -Sb 2 Se 3 /NiO/C-fabric cell is 5.96% (0.11 cm 2 area), which, when replicated on a smaller area of 0.06 cm 2 , is seen to increase dramatically to 7.19%. The cell is also tested for 6 h of continuous irradiance. The rationalization for the channelized photogenerated electron movement, which augments the cell performance, is furnished in detail in these studies.

LABORATORY OPTIMIZATION TESTS OF TECHNETIUM DECONTAMINATION OF HANFORD WASTE TREATMENT PLANT LOW ACTIVITY WASTE OFF-GAS CONDENSATE SIMULANT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor-Pashow, K.; Nash, C.; McCabe, D.

2014-09-29

compatible with longterm tank storage and immobilization methods. For this new application, testing is needed to demonstrate acceptable treatment sorbents and precipitating agents and measure decontamination factors for additional radionuclides in this unique waste stream. The origin of this LAW Off-Gas Condensate stream will be the liquids from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover. The soluble components are expected to be mostly sodium and ammonium salts of nitrate, chloride, and fluoride. This stream has not been generated yet and will not be available until the WTP begins operation, but a simulant has been produced based on models, calculations, and comparison with pilot-scale tests. One of the radionuclides that is volatile and expected to be in greatest abundance in this LAW Off-Gas Condensate stream is Technetium-99 ({sup 99}Tc). Technetium will not be removed from the aqueous waste in the Hanford WTP, and will primarily end up immobilized in the LAW glass by repeated recycle of the off-gas condensate into the LAW melter. Other radionuclides that are low but are also expected to be in measurable concentration in the LAW Off-Gas Condensate are {sup 129}I, {sup 90}Sr, {sup 137}Cs, {sup 241}Pu, and {sup 241}Am. These are present due to their partial volatility and some entrainment in the off-gas system. This report discusses results of optimized {sup 99}Tc decontamination testing of the simulant. Testing examined use of inorganic reducing agents for {sup 99}Tc. Testing focused on minimizing the quantity of sorbents/reactants added, and minimizing mixing time to reach the decontamination targets in this simulant formulation. Stannous chloride and ferrous sulfate were tested as reducing agents to determine the minimum needed to convert soluble pertechnetate

University of Maryland MRSEC - News: Featured

Science.gov Websites

state at surface of bismuth selenide Completed device MRSEC research, published in NanoLetters ASAP in and M. S. Fuhrer, "Insulating behavior in ultrathin bismuth selenide field effect transistors

Thin-film semiconductor rectifier has improved properties

NASA Technical Reports Server (NTRS)

1966-01-01

Cadmium selenide-zinc selenide film is used as a thin film semiconductor rectifier. The film is vapor-deposited in a controlled concentration gradient into a glass substrate to form the required junctions between vapor-deposited gold electrodes.

99mTechnetium and methylene blue guided pulmonary nodules resections: preliminary British experience.

PubMed

Nardini, Marco; Bilancia, Rocco; Paul, Ian; Jayakumar, Shruti; Papoulidis, Pavlos; ElSaegh, Mohamed; Hartley, Richard; Richardson, Mark; Misra, Pankash; Migliore, Marcello; Dunning, Joel

2018-02-01

Subcentimetre pulmonary nodules can be challenging to locate either during video-assisted thoracoscopic surgery (VATS) or by open techniques. In an era of increasing computed tomography scan availability the number of nodules that are identified that are suspicious for malignancy is rising, and thoracic surgeons require a reliable method to locate these nodules intraoperatively. Our aim was to evaluate, for the first time in the UK, resection of pulmonary nodules using radioactive dye labelling. Local research ethics approval was obtained and the study was submitted to the Integrated Research Application System (IRAS). All data were prospectively collected in our dedicated thoracic surgical database and analyzed at the conclusion of the study. This represents a consecutive series of patients, from January 2016 and until April 2017, who underwent this procedure at our institution: James Cook University Hospital, Middlesbrough, United Kingdom. The primary outcome measured was successful resection rate of the target nodules. Twenty-three patients underwent radiolabeled excision of pulmonary nodules, their average age was 61 years (range, 28-79 years), 13 women and 10 men. The average maximum diameter of the nodule was 8 mm (range, 3-16 mm). All patients underwent successful excision of the target lesion (success rate 100%). One patient (4.3%) sustained pneumothorax following the CT-guided injection of the radio-labelled dye and this required chest drainage prior to general anesthesia. We conclude that technetium guided pulmonary nodule resection is a very reliable method for localization and resection of subcentimetre nodules which may be otherwise be difficult to identify.

99mTechnetium and methylene blue guided pulmonary nodules resections: preliminary British experience

PubMed Central

Bilancia, Rocco; Paul, Ian; Jayakumar, Shruti; Papoulidis, Pavlos; ElSaegh, Mohamed; Hartley, Richard; Richardson, Mark; Misra, Pankash; Migliore, Marcello; Dunning, Joel

2018-01-01

Background Subcentimetre pulmonary nodules can be challenging to locate either during video-assisted thoracoscopic surgery (VATS) or by open techniques. In an era of increasing computed tomography scan availability the number of nodules that are identified that are suspicious for malignancy is rising, and thoracic surgeons require a reliable method to locate these nodules intraoperatively. Methods Our aim was to evaluate, for the first time in the UK, resection of pulmonary nodules using radioactive dye labelling. Local research ethics approval was obtained and the study was submitted to the Integrated Research Application System (IRAS). All data were prospectively collected in our dedicated thoracic surgical database and analyzed at the conclusion of the study. This represents a consecutive series of patients, from January 2016 and until April 2017, who underwent this procedure at our institution: James Cook University Hospital, Middlesbrough, United Kingdom. The primary outcome measured was successful resection rate of the target nodules. Results Twenty-three patients underwent radiolabeled excision of pulmonary nodules, their average age was 61 years (range, 28–79 years), 13 women and 10 men. The average maximum diameter of the nodule was 8 mm (range, 3–16 mm). All patients underwent successful excision of the target lesion (success rate 100%). One patient (4.3%) sustained pneumothorax following the CT-guided injection of the radio-labelled dye and this required chest drainage prior to general anesthesia. Conclusions We conclude that technetium guided pulmonary nodule resection is a very reliable method for localization and resection of subcentimetre nodules which may be otherwise be difficult to identify. PMID:29607175

[Evaluation of green indocyanine interest compared to Technetium in sentinel lymph node detection in breast cancer].

PubMed

Guenane, Y; Gorj, M; Nguyen, V; Revol, M; Mazouz-Dorval, S

2016-12-01

Axillary sentinel lymph node (SN) biopsy by using indocyanine green (ICG) fluorescence for breast cancer is a recent technique. However, compared to Technetium-99m (Tc), which is the reference technique, its efficiency has received little testing. Between December 2013 and January 2014, 40 patients with node-negative breast cancer underwent SN biopsy by injecting sub areolar Tc in preoperative stage and injecting sub areolar ICG in intraoperative stage. SN were previously identified and resected by using ICG coupled with infrared camera. After resection of fluorescent SN, we check its radioactivity with a gamma probe (isotopic method). In case of residual radioactive labeling in the axillary crease, we remove the remaining SN. We have retrospectively analyzed the SN detection concordance rates of these two methods. In total we resected 53 SN, among which 48 (90.6%) were indocyanine green positive and 53 (100%) Tc positive. The remaining 5 SN were all ICG negative and Tc positive. Using ICG has not caused any side effect. SN detection for breast cancer by using ICG fluorescence is a promising, reliable technique which nonetheless requires a degree of expertise before reaching similar results as the Tc technique. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

PubMed

McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A

2012-11-20

The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be <10 ppm (by mass), these Re results implied that the solubility should not be a limiting factor in processing radioactive wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

Design of Multifunctional Materials: Chalcogenides and Chalcopyrites

NASA Technical Reports Server (NTRS)

Singh, N. B.; Su, Ching Hua; Arnold, Brad; Choa, Fow-Sen

2017-01-01

There is a strong need for developing multifunctional materials to reduce the cost of applied material without compromising the performance of the detectors, devices and sensors. The materials design, processing, growth and fabrication of bulk and nanocrystals and fabrication into devices and sensors involve huge cost and resources including a multidisciplinary team of experts. Because of this reason, prediction of multifunctionality of materials before design and development should be evaluated. Chalcogenides and chalcopyrites are a very exciting class of materials for developing multifunctionality. Materials such as Gallium selenide GaSe and zinc selenide ZnSe have been proven to be excellent examples. GaSe is a layered material and very difficult to grow in large crystal. However, it's ternary and quaternary analogs such as thallium gallium selenide TlGaSe2, thallium gallium selenide sulfide TlGaSe2-xSs, thallium arsenic selenide Tl3AsSe3, silver gallium selenide AgGaGe3Se8, AgGaGe5Se12 and several others have shown great promise for multifunctionality. Several of these materials have shown good efficiency for frequency conversion (nonlinear optical NLO), electro-optic modulation, and acousto-optic tunable filters and imagers suitable for the visible, near-infrared wavelength, mid wave infrared (MWIR), long wave infrared (LWIR) and even up to Tera hertz wavelength (THW) regions. In addition, this class of materials have demonstrated low absorption coefficients and power handling capability in the systems. Also, these crystals do not require post growth annealing, show very large transparency range and fabricability.

EVALUATION OF VADOSE ZONE TREATMENT TECHNOLOGIES TO IMMOBILIZE TECHNETIUM-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

PETERSEN, S.W.

2006-03-15

The Hanford Site End State Vision document (DOE/RL-2003-59) states: ''There should be an aggressive plan to develop technology for remediation of the contamination that could get to the groundwater (particularly the technetium [{sup 99}Tc])''. In addition, there is strong support from the public and regulatory agencies for the above statement, with emphasis on investigation of treatment alternatives. In July 2004, PNNL completed a preliminary evaluation of remediation technologies with respect to their effectiveness and implementability for immobilization of {sup 99}Tc beneath the BC Cribs in the 200 West Area (Truex, 2004). As a result of this evaluation, PNNL recommended treatabilitymore » testing of in situ soil desiccation, because it has the least uncertainty of those technologies evaluated in July 2004 (Treatability Test Outline, September 30, 2004). In 2005, DOE-RL and Fluor Hanford convened an independent technical panel to review alternative remediation technologies, including desiccation, at a three-day workshop in Richland, Washington. The panel was composed of experts in vadose-zone transport, infiltration control, hydrology, geochemistry, environmental engineering, and geology. Their backgrounds include employment in academia, government laboratories, industry, and consulting. Their review, presented in this document, is based upon written reports from Hanford, oral presentations from Hanford staff, and each panel members' years of experience in their particular field of expertise. The purpose of this report is to document the panel's evaluation of various treatment alternatives with potential for minimizing contaminant migration in the deep vadose zone at the Department of Energy Hanford Site. The panel was tasked with assessing the most viable and practical approach and making recommendations for testing. The evaluation of vadose-zone treatment alternatives was conducted to be broadly applicable at a variety of locations at Hanford. However

Hot-electron transfer in quantum-dot heterojunction films.

PubMed

Grimaldi, Gianluca; Crisp, Ryan W; Ten Brinck, Stephanie; Zapata, Felipe; van Ouwendorp, Michiko; Renaud, Nicolas; Kirkwood, Nicholas; Evers, Wiel H; Kinge, Sachin; Infante, Ivan; Siebbeles, Laurens D A; Houtepen, Arjan J

2018-06-13

Thermalization losses limit the photon-to-power conversion of solar cells at the high-energy side of the solar spectrum, as electrons quickly lose their energy relaxing to the band edge. Hot-electron transfer could reduce these losses. Here, we demonstrate fast and efficient hot-electron transfer between lead selenide and cadmium selenide quantum dots assembled in a quantum-dot heterojunction solid. In this system, the energy structure of the absorber material and of the electron extracting material can be easily tuned via a variation of quantum-dot size, allowing us to tailor the energetics of the transfer process for device applications. The efficiency of the transfer process increases with excitation energy as a result of the more favorable competition between hot-electron transfer and electron cooling. The experimental picture is supported by time-domain density functional theory calculations, showing that electron density is transferred from lead selenide to cadmium selenide quantum dots on the sub-picosecond timescale.

Technetium-99 conjugated with methylene diphosphonate ameliorates ovariectomy-induced osteoporotic phenotype without causing osteonecrosis in the jaw.

PubMed

Zhao, Yinghua; Wang, Lei; Liu, Yi; Akiyama, Kentaro; Chen, Chider; Atsuta, Ikiru; Zhou, Tao; Duan, Xiaohong; Jin, Yan; Shi, Songtao

2012-12-01

Technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP) is a novel bisphosphonate derivative without radioactivity and has been successfully used to treat arthritis in China for years. Since bisphosphonate therapy has the potential to induce bisphosphonate-related osteonecrosis of the jaw (BRONJ), we examined whether (99)Tc-MDP represents a new class of bisphosphonate for antiresorptive therapy to ameliorate estrogen deficiency-induced bone resorption with less risk of causing BRONJ. We showed that (99)Tc-MDP-treated, ovariectomized (OVX) mice had significantly improved bone mineral density and trabecular bone volume in comparison to the untreated OVX group by inhibiting osteoclasts and enhancing osteogenic differentiation of bone marrow mesenchymal stem cells. To determine the potential of inducing BRONJ, (99)Tc-MDP/dexamethasone (Dex) or zoledronate/Dex was administered into C57BL/6J mice via the tail vein, followed by extraction of maxillary first molars. Interestingly, (99)Tc-MDP treatment showed less risk to induce osteonecrosis in the maxillary bones compared to zoledronate treatment group, partially because (99)Tc-MDP neither suppressed adaptive regulatory T cells nor activated the inflammatory T-helper-producing interleukin-17 cells. Taken together, our findings demonstrate that (99)Tc-MDP therapy may be a promising approach in the treatment of osteoporosis with less risk of causing BRONJ.

Options for the Separation and Immobilization of Technetium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R Jeffrey; Crum, Jarrod V.; Riley, Brian J.

Among radioactive constituents present in the Hanford tank waste, technetium-99 (Tc) presents a unique challenge in that it is significantly radiotoxic, exists predominantly in the liquid low-activity waste (LAW), and has proven difficult to effectively stabilize in a waste form for ultimate disposal. Within the Hanford Tank Waste Treatment and Immobilization Plant, the LAW fraction will be converted to a glass waste form in the LAW vitrification facility, but a significant fraction of Tc volatilizes at the high glass-melting temperatures and is captured in the off-gas treatment system. This necessitates recycle of the off-gas condensate solution to the LAW glassmore » melter feed. The recycle process is effective in increasing the loading of Tc in the immobilized LAW (ILAW), but it also disproportionately increases the sulfur and halides in the LAW melter feed, which have limited solubility in the LAW glass and thus significantly reduce the amount of LAW (glass waste loading) that can be vitrified and still maintain good waste form properties. This increases both the amount of LAW glass and either the duration of the LAW vitrification mission or requires the need for supplemental LAW treatment capacity. Several options are being considered to address this issue. Two approaches attempt to minimize the off-gas recycle by removing Tc at one of several possible points within the tank waste processing flowsheet. The separated Tc from these two approaches must then be dispositioned in a manner such that the Tc can be safely disposed. Alternative waste forms that do not have the Tc volatility issues associated with the vitrification process are being sought for immobilization of Tc for subsequent storage and disposal. The first objective of this report is to provide insights into the compositions and volumes of the Tc-bearing waste streams including the ion exchange eluate from processing LAW and the off-gas condensate from the melter. The first step to be assessed

Evaluation of technetium-99m decay on Escherichia coli inactivation: effects of physical or chemical agents.

PubMed Central

Silva, C. R.; Valsa, J. O.; Caniné, M. S.; Caldeira-de-Araújo, A.; Bernardo-Filho, M.

1998-01-01

Technetium-99m (99mTc) has been used in nuclear medicine and in biomedical research to label molecular and cellular structures employed as radiotracers. Here, we have evaluated, on a DNA repair proficient Escherichia coli strain, the 99mTc decay inactivation and the influence of the (i) pre-treatment with metal ion chelators or of the (ii) treatment with a free radical scavenger on the protection of the cells against the lethal effect of the 99mTc. As SnCl2 is frequently used as a reducing agent in the 99mTc-labeling process, we have also studied the capability of SnCl2 to alter the biological effects induced by the 99mTc decay. As we are exposed to either chemical or physical agents in the nature, we have decided to study a possible influence of the ultraviolet solar radiation in the biological phenomena induced by the 99mTc decay. Our data point out (i) a very important role of the Auger and/or conversion electrons in the cytotoxicity induced by the 99mTc decay; (ii) SnCl2, the metal ion chelators and the free radical scavenger protect the cells against the lethal effect of the 99mTc; and (iii) near-UV does not alter the lethal effect of the 99mTc decay. PMID:9713950

Structural and Perfusion Abnormalities of Brain on MRI and Technetium-99m-ECD SPECT in Children With Cerebral Palsy: A Comparative Study.

PubMed

Rana, Kamer Singh; Narwal, Varun; Chauhan, Lokesh; Singh, Giriraj; Sharma, Monica; Chauhan, Suneel

2016-04-01

Cerebral palsy has traditionally been associated with hypoxic ischemic brain damage. This study was undertaken to demonstrate structural and perfusion brain abnormalities. Fifty-six children diagnosed clinically as having cerebral palsy were studied between 1 to 14 years of age and were subjected to 3 Tesla magnetic resonance imaging (MRI). Brain and Technetium-99m-ECD brain single-photon emission computed tomography (SPECT) scan. Male to female ratio was 1.8:1 with a mean age of 4.16 ± 2.274 years. Spastic cerebral palsy was the most common type, observed in 91%. Birth asphyxia was the most common etiology (69.6%). White matter changes (73.2%) such as periventricular leukomalacia and corpus callosal thinning were the most common findings on MRI. On SPECT all cases except one revealed perfusion impairments in different regions of brain. MRI is more sensitive in detecting white matter changes, whereas SPECT is better in detecting cortical and subcortical gray matter abnormalities of perfusion. © The Author(s) 2015.

Ultrasensitive sensing platform for platelet-derived growth factor BB detection based on layered molybdenum selenide-graphene composites and Exonuclease III assisted signal amplification.

PubMed

Huang, Ke-Jing; Shuai, Hong-Lei; Zhang, Ji-Zong

2016-03-15

A highly sensitive and ultrasensitive electrochemical aptasensor for platelet-derived growth factor BB (PDGF-BB) detection is fabricated based on layered molybdenum selenide-graphene (MoSe2-Gr) composites and Exonuclease III (Exo III)-aided signal amplification. MoSe2-Gr is prepared by a simple hydrothermal method and used as a promising sensing platform. Exo III has a specifical exo-deoxyribonuclease activity for duplex DNAs in the direction from 3' to 5' terminus, however its activity is limited on the duplex DNAs with more than 4 mismatched terminal bases at 3' ends. Herein, aptamer and complementary DNA (cDNA) sequences are designed with four thymine bases on 3' ends. In the presence of target protein, the aptamer associates with it and facilitates the formation of duplex DNA between cDNA and signal DNA. The duplex DNA then is digested by Exo III and releases cDNA, which hybridizes with signal DNA to perform a new cleavage process. Nevertheless, in the absence of target protein, the aptamer hybridizes with cDNA will inhibit the Exo III-assisted nucleotides cleavage. The signal DNA then hybridizes with capture DNA on the electrode. Subsequently, horse radish peroxidase is fixed on electrode by avidin-biotin reaction and then catalyzes hydrogen peroxide and hydroquinone to produce electrochemical response. Therefore, a bridge can be established between the concentration of target protein and the degree of the attenuation of the obtained signal, providing a quantitative measure of target protein with a broad detection range of 0.0001-1 nM and a detection limit of 20 fM. Copyright © 2015 Elsevier B.V. All rights reserved.

An Experimental Comparison of Two Different Technetium Source Activities Which Can Imitate Thyroid Scintigraphy in Case of Thyroid Toxic Nodule

PubMed Central

Miftari, Ramë; Fejza, Ferki; Bicaj, Xhavit; Nura, Adem; Topciu, Valdete; Bajrami, Ismet

2014-01-01

Purpose: In cases of thyroid toxic autonomous nodule, anterior projection of Tc-99m pertechnetate image shows a hot nodule that occupies most, or the entire thyroid lobe with near-total or total suppression of the contra lateral lobe. In this case is very difficult to distinguish toxic nodule from lobe agenesis. Our interest was to estimate and determinate the rate of radioactivity when the source with high activity can make total suppression of the second source with low activity in same conditions with thyroid scintigraphy procedures. Material and methodology: Thyroid scintigraphy was performed with Technetium 99 meta stable pertechnetate. A parallel high resolution low energy collimator was used as an energy setting of 140 KeV photo peak for T-99m. Images are acquired at 200 Kilo Counts in the anterior projection with the collimator positioned as close as the patient’s extended neck (approximately in distance of 18 cm). The scintigraphy of thyroid gland was performed 15 minutes after intravenous administration of 1.5 mCi Tc-99m pertechnetate. Technetium 99 meta stable radioactive sources with different activity were used for two scintigraphies studies, performed in same thyroid scintigraphy acquisition procedures. In the first study, were compared the standard source with high activity A=11.2 mCi with sources with variable activities B=1.33 mCi; 1.03 mCi; 0.7 mCi; 0.36 mCi; and 0.16mCi) in distance of 1.5cm from each other sources, which is approximately same with distance between two thyroid lobes. In the second study were compared the sources with low activity in proportion 70:1(source A = 1.5 mCi and source B=0.021mCi). As clinical studies we preferred two different patents with different thyroid disorders. There were one patient with thyroid toxic nodule in the right lobe, therefore the second patient was with left thyroid nodule agenesis. Results: During our examination, we accurately determined that two radioactive sources in proportion 70:1 will be

Early identification of amyloid heart disease by technetium-99m-pyrophosphate scintigraphy: a study with familial amyloid polyneuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hongo, M.; Hirayama, J.; Fujii, T.

1987-03-01

To determine whether technetium-99m-pyrophosphate (Tc-99m-PYP) scanning or two-dimensional echocardiography can detect amyloid heart disease in an earlier stage of familial amyloid polyneuropathy, 15 patients were examined. Although 10 of the 15 patients had no clinical evidence of congestive heart failure, as well as normal ventricular wall thickness and normal values for left ventricular systolic function, five (50%) of them showed mild or moderate myocardial uptake. On the other hand, none had characteristic highly refractile myocardial echoes on the two-dimensional echocardiographic images (p less than 0.01), and values for diastolic function were reduced in four of the five and normal inmore » the remaining one. In 85 control subjects, diffuse positive pyrophosphate scans of the heart were found in four (5%) of them (three with dilated cardiomyopathy and one with sarcoidosis), and highly refractile granular sparkling echoes were observed in nine (11%) (five with hypertrophic cardiomyopathy, three with aortic stenosis, and one with hypereosinophilic syndrome). We conclude that Tc-99m-PYP scanning is a more sensitive and specific method and may have the potential ability to detect amyloid heart disease in the earlier stage of familial amyloid polyneuropathy than two-dimensional echocardiography.« less

Quantitative single-photon emission computed tomography/computed tomography for technetium pertechnetate thyroid uptake measurement

PubMed Central

Lee, Hyunjong; Kim, Ji Hyun; Kang, Yeon-koo; Moon, Jae Hoon; So, Young; Lee, Won Woo

2016-01-01

Abstract Objectives: Technetium pertechnetate (99mTcO4) is a radioactive tracer used to assess thyroid function by thyroid uptake system (TUS). However, the TUS often fails to deliver accurate measurements of the percent of thyroid uptake (%thyroid uptake) of 99mTcO4. Here, we investigated the usefulness of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) after injection of 99mTcO4 in detecting thyroid function abnormalities. Materials and methods: We retrospectively reviewed data from 50 patients (male:female = 15:35; age, 46.2 ± 16.3 years; 17 Graves disease, 13 thyroiditis, and 20 euthyroid). All patients underwent 99mTcO4 quantitative SPECT/CT (185 MBq = 5 mCi), which yielded %thyroid uptake and standardized uptake value (SUV). Twenty-one (10 Graves disease and 11 thyroiditis) of the 50 patients also underwent conventional %thyroid uptake measurements using a TUS. Results: Quantitative SPECT/CT parameters (%thyroid uptake, SUVmean, and SUVmax) were the highest in Graves disease, second highest in euthyroid, and lowest in thyroiditis (P < 0.0001, Kruskal–Wallis test). TUS significantly overestimated the %thyroid uptake compared with SPECT/CT (P < 0.0001, paired t test) because other 99mTcO4 sources in addition to thyroid, such as salivary glands and saliva, contributed to the %thyroid uptake result by TUS, whereas %thyroid uptake, SUVmean and SUVmax from the SPECT/CT were associated with the functional status of thyroid. Conclusions: Quantitative SPECT/CT is more accurate than conventional TUS for measuring 99mTcO4 %thyroid uptake. Quantitative measurements using SPECT/CT may facilitate more accurate assessment of thyroid tracer uptake. PMID:27399139

Inhibitors of the serotonin transporter protein (SERT): the design and synthesis of biotinylated derivatives of 3-(1,2,3,6-tetrahydro-pyridin-4-yl)-1H-indoles. High-affinity serotonergic ligands for conjugation with quantum dots.

PubMed

Tomlinson, Ian D; Mason, John N; Blakely, Randy D; Rosenthal, Sandra J

2005-12-01

There is a growing demand for compounds with specificity for the serotonin transporter protein (SERT) that can be conjugated to cadmium selenide/zinc sulfide core shell nanocrystals. This letter describes the design and synthesis of two different biotinylated SERT antagonists that can be attached to streptavidin-coated cadmium selenide/zinc sulfide core shell nanocrystals.

10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Technetium-97m 100 Technetium-97 100 Technetium-99m 100 Technetium-99 10 Tellurium-125m 10 Tellurium-127m 10 Tellurium-127 100 Tellurium-129m 10 Tellurium-129 100 Tellurium-131m 10 Tellurium-132 10...

10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Technetium-97m 100 Technetium-97 100 Technetium-99m 100 Technetium-99 10 Tellurium-125m 10 Tellurium-127m 10 Tellurium-127 100 Tellurium-129m 10 Tellurium-129 100 Tellurium-131m 10 Tellurium-132 10...

THE RESULTS OF PARATHYROID HORMONE ASSAY IN PARATHYROID ASPIRATES IN PRE-OPERATIVE LOCALIZATION OF PARATHYROID ADENOMAS FOR FOCUSED PARATHYROIDECTOMY IN PATIENTS WITH NEGATIVE OR SUSPICIOUS TECHNETIUM-99M-SESTAMIBI SCANS.

PubMed

Ozderya, Aysenur; Temizkan, Sule; Cetin, Kenan; Ozugur, Sule; Gul, Aylin Ege; Aydin, Kadriye

2017-09-01

This study aimed to evaluate the results of parathyroid hormone (PTH) assay in parathyroid aspirates to determine uniglandular disease by an endocrinologist-performed ultrasound (US) in patients with discordant or negative technetium-sestamibi scans and to evaluate whether this procedure increases the number of focused parathyroidectomies (FPs). We analyzed the data of 65 patients who underwent an endocrinologist-performed US-guided parathyroid fine-needle aspiration (FNA) with PTH wash-out, retrospectively. The results of PTH wash-out procedure and the reports of parathyroid surgery and pathology were reviewed. Of 65 patients, 54 had positive PTH wash-out results. The median serum PTH level of patients with positive and negative PTH wash-out results was 143 (25 and 75% interquartile range [IQR], 114 to 197) versus 154 (IQR, 115 to 255) pg/mL (P = .45), and the median PTH in FNA was 3,533 (IQR, 1,481 to 3,534) versus 6.0 (IQR, 1 to 6) pg/mL (P<.001), respectively. Forty-five patients underwent surgery. Of the operated patients, 42 had positive PTH wash-out results and had successful FP. Four patients with redo surgery had positive PTH wash-out results and were successfully re-operated with FP. Of 11 patients with negative PTH wash-out results, 3 had bilateral neck exploration (BNE) surgery and 2 patients were successfully operated, while surgery was unsuccessful in 1 patient, despite BNE. Our study results suggest that endocrinologist-performed US and parathyroid FNA with PTH wash-out increases the number and success of FPs. In particular, patients with redo surgery may benefit from this procedure. 4D-CT = four-dimensional computed tomography BNE = bilateral neck exploration FNA = fine-needle aspiration FNAB = fine-needle aspiration biopsy FP = focused parathyroidectomy IQR = 25 and 75% inter-quartile range PHPT = primary hyperparathyroidism PPV = positive predictive value PTH = parathyroid hormone 99m Tc = technetium US = ultrasound.

Characterization of Materials by Raman Scattering

NASA Astrophysics Data System (ADS)

Kozielski, M.

2007-03-01

The paper reports on the use of phonon spectra obtained with the Raman spectroscopy for characterization of different materials. The Raman scattering spectra obtained for zinc selenide crystals, mixed crystals zinc selenide admixtured with magnesium or beryllium, oxide crystals including strontium lanthanum gallate, molecular crystals of triammonium hydrogen diseleniate and a homologous series of polyoxyethylene glycols are analysed.

Development of advanced thermoelectric materials, phase A

NASA Technical Reports Server (NTRS)

1980-01-01

Work performed on the chemical system characterized by chrome sulfide, chrome selenide, lanthanum selenide, and lanthanum sulfide is described. Most materials within the chemical systems possess the requisites for attractive thermoelectric materials. The preparation of the alloys is discussed. Graphs show the Seebeck coefficient, electrical resistivity, and thermal conductivity of various materials within the chemical systems. The results of selected doping are included.

Detecting Myocardial Ischemia With 99mTechnetium-Tetrofosmin Myocardial Perfusion Imaging in Ischemic Stroke.

PubMed

Giannopoulos, Sotirios; Markoula, Sofia; Sioka, Chrissa; Zouroudi, Sofia; Spiliotopoulou, Maria; Naka, Katerina K; Michalis, Lampros K; Fotopoulos, Andreas; Kyritsis, Athanassios P

2017-10-01

To assess the myocardial status in patients with stroke, employing myocardial perfusion imaging (MPI) with 99m Technetium-tetrofosmin ( 99m Tc-TF)-single-photon emission computed tomography (SPECT). Fifty-two patients with ischemic stroke were subjected to 99m Tc-TF-SPECT MPI within 1 month after stroke occurrence. None of the patients had any history or symptoms of coronary artery disease or other heart disease. Myocardial perfusion imaging was evaluated visually using a 17-segment polar map. Myocardial ischemia (MIS) was defined as present when the summed stress score (SSS) was >4; MIS was defined as mild when SSS was 4 to 8, and moderate/severe with SSS ≥9. Patients with SSS >4 were compared to patients with SSS <4. Parameters such as age, body mass index, waist perimeter, smoking habits, and medical history (diabetes mellitus, dyslipidemia, etc) were evaluated according to MPI results. Myocardial ischemia was present in 32 (62%) of 52 patients with stroke. Among them, 20 (62%) of 32 patients had mild abnormalities and 12 (38%) of 32 had moderate/severe. The age and waist perimeter showed a tendency to relate to severe MIS when patients with SSS >9 were compared to patients with SSS <4. In MPI-positive patients, an age was to be association with SSS, with the oldest age exhibiting the highest SSS ( P = .01). The association of age with SSS remained statistically significant in the multivariate analysis ( P = .04). The study suggested that more than half of patients with stroke without a history of cardiac disease have MIS. Although most of them have mild MIS, we suggest a thorough cardiological evaluation in this group of patients for future prevention of severe myocardial outcome.

[Situation of supply and boom of PET imaging: what is the future for technetium-99m in nuclear medicine?].

PubMed

Maia, S; Ayachi Hatit, N; Paycha, F

2011-05-01

Molecular imaging has shown its interest in the diagnosis, staging and therapy monitoring of many diseases, especially in the field of cancer. This imaging modality can detect non-invasively early molecular changes specific to these diseases. Its expansion includes two aspects linked firstly with the advanced techniques of imaging modalities and secondly with the development of tracers as radio pharmaceuticals for imaging new molecular targets. Technetium-99m ((99m)Tc), because of its physical characteristics, its widespread availability and low cost, is the most used radionuclide in molecular imaging with the technique of single photon emission computed tomography (SPECT). Nevertheless, the current difficulty concerning the supply and the great interest of Positron Emission Tomography (PET), the "competitor" imaging modality-using molecules labelled with fluorine-18 ((18)F), legitimates the question about the future of (99m)Tc, its supremacy and the emergence of new tracer labelled with (99m)Tc. Focusing on the actual and future supply situation, the place of SPECT imaging in nuclear medicine, as well as the development of new molecules labelled with (99m)Tc is necessary to show that this radionuclide will remain essential for the speciality in the next years. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Dissimilar behavior of technetium and rhenium in borosilicatewaste glass as determined by X-ray absorption spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lukens, Wayne W.; McKeown, David A.; Buechele, Andrew C.

2006-11-09

Technetium-99 is an abundant, long-lived (t1/2 = 213,000 yr)fission product that creates challenges for the safe, long-term disposalof nuclear waste. While 99Tc receives attention largely due to its highenvironmental mobility, it also causes problems during its incorporationinto nuclear waste glass due to the volatility of Tc(VII) compounds. Thisvolatility decreases the amount of 99Tc stabilized in the waste glass andcauses contamination of the waste glass melter and off-gas system. Theapproach to decrease the volatility of 99Tc that has received the mostattention is reduction of the volatile Tc(VII) species to less volatileTc(IV) species in the glass melt. On engineering scale experiments,rhenium ismore » often used as a non-radioactive surrogate for 99Tc to avoidthe radioactive contamination problems caused by volatile 99Tc compounds.However, Re(VII) is more stable towards reduction than Tc(VII), so morereducing conditions would be required in the glass melt to produceRe(IV). To better understand the redox behavior of Tc and Re in nuclearwaste glass, a series of glasses were prepared under different redoxconditions. The speciation of Tc and Re in the resulting glasses wasdetermined by X-ray absorption fine structure spectroscopy. Surprisingly,Re and Tc do not behave similarly in the glass melt. Although Tc(0),Tc(IV), and Tc(VII) were observed in these samples, only Re(0) andRe(VII) were found. In no case was Re(IV) (or Re(VI))observed.« less

Rhenium Solubility in Borosilicate Nuclear Waste Glass: Implications for the Processing and Immobilization of Technetium-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, John S.; Riley, Brian J.; Goel, Ashutosh

2012-10-26

The immobilization of 99Tc in a suitable host matrix has proved to be an arduous task for the researchers in nuclear waste community around the world. At the Hanford site in Washington State, the total amount of 99Tc in low-activity waste (LAW) is ~1300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility/retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of the similarity between theirmore » ionic radii and other chemical aspects. The glasses containing Re (0 – 10,000 ppm by mass) were synthesized in vacuum-sealed quartz ampoules in order to minimize the loss of Re by volatilization during melting at 1000 °C. The rhenium was found to predominantly exist as Re (VII) in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) with inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of crystalline inclusions that were detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). The implications of these results on the immobilization of 99Tc from radioactive wastes in borosilicate glasses have been discussed.« less

Recruitment of 99m-technetium- or 111-indium-labelled polymorphonuclear leucocytes in experimentally induced pyogranulomas in lambs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guilloteau, L.; Pepin, M.; Pardon, P.

1990-10-01

The recruitment of polymorphonuclear leucocytes (PMNs) during the development of experimental pyogranulomas induced by Corynebacterium pseudotuberculosis was followed in nine male lambs by scintigraphic examination. Autologous blood PMNs were labelled with 99m-technetium or 111-indium and were re-injected intravenously into infected lambs. The functional properties of the labelled cells were monitored (1) in vitro by measuring their phagocytic and bactericidal activity against C. pseudotuberculosis and their chemotaxis under agarose, and (2) in vivo by following scintigraphically their capacity to accumulate in an inflammatory focus induced by intradermal injection of latex beads coated with Salmonella abortus equi lipopolysaccharide. Following inoculation of corynebacteriamore » into the right ear of lambs, radioactive foci were observed to be localized in the right ear and in the draining lymph nodes during the 4 days following inoculation. Histopathological examination performed 32 h after inoculation confirmed the intense accumulation of PMNs at these sites. With the exception of one animal, which presented visible foci in the neck 14 days postinoculation, no radioactive foci were observed during the later phases of experimental infection, despite the presence of multiple pyogranulomas which were confirmed by bacteriological examination after necropsy of the lambs. Histopathological examination of these lesions revealed layers of fibroblasts, lymphocytes, and macrophages surrounding a necrotic centre. The results of these studies suggest that the contribution of PMNs during the chronic phase of inflammation is considerably reduced in comparison with the acute inflammatory phase of the infectious process.« less

Comparison of technetium-99m-HM-PAO leukocytes with indium-111-oxine leukocytes for localizing intraabdominal sepsis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mountford, P.J.; Kettle, A.G.; O'Doherty, M.J.

Technetium-99m-HM-PAO (({sup 99m}Tc)HM-PAO) leukocyte and indium-111-oxine (111In-oxine) leukocyte scanning were carried out simultaneously in 41 patients at 4 hr and 24 hr after reinjection to determine whether the 4-hr {sup 99m}Tc scan could replace the 24-hr {sup 111}In scan for detecting intraabdominal sepsis. Abdominal infection was confirmed in 12 cases. The 4-hr {sup 99}Tc-leukocyte scan, the 4-hr {sup 111}In-leukocyte scan, and the 24-hr {sup 111}In-leukocyte scan yielded a sensitivity of 100%, 67%, and 100%, respectively, and a specificity of 62%, 90%, and 86%, respectively. The 24-hr {sup 99m}Tc-leukocyte scan also produced a sensitivity of 100%, but it was falsely positivemore » in all 29 cases without infection due to physiologic bowel uptake. False-positive 4-hr {sup 99m}Tc-leukocyte scans were also produced by physiologic bowel uptake in seven cases all of whom had true-negative 4-hr and 24-hr {sup 111}In-leukocyte scans. Because of the high incidence of false-positive 4-hr ({sup 99m}Tc)HM-PAO leukocyte scans, it was concluded that they could not replace 24-hr {sup 111}In-leukocyte scans for detecting intraabdominal sepsis, and that serial {sup 99m}Tc leukocyte scans starting earlier than 4 hr after reinjection must be evaluated.« less

Modeling and Simulation of a Dual-Junction CIGS Solar Cell Using Silvaco ATLAS

DTIC Science & Technology

2012-12-01

junction Copper Indium Gallium Selenide (CIGS) photovoltaic cell is investigated in this thesis. Research into implementing a dual-junction solar cell...Silvaco ATLASTM model of a single CIGS cell was created by utilizing actual solar cell parameters (such as layer thicknesses, gallium ratio, doping...THIS PAGE INTENTIONALLY LEFT BLANK v ABSTRACT The potential of designing a dual-junction Copper Indium Gallium Selenide (CIGS) photovoltaic

Optical Jitter Effects on Target Detection and Tracking of Overhead Persistent Infrared Systems

DTIC Science & Technology

2015-12-01

infrared CdSe cadmium selenide DSP Defense Support Program FIR far-infrared FPA focal plane array Ge germanium GEO geostationary earth orbit...HBCRT High Energy Laser Beam Control Research Testbed HEL high energy laser HgCdTe mercury cadmium telluride IR infrared InSb indium antimonide...MOD model MTF modulation transfer function MWIR mid-wave infrared NIR near infrared OPIR overhead persistent infrared PbSe lead selenide

Synthesis and magnetic structure of the layered manganese oxide selenide Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blandy, Jack N.; Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE; Boskovic, Jelena C.

The synthesis of a high-purity sample of the layered oxide selenide Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} is reported. At ambient temperature it crystallises in the space group I4/mmm with two formula units in the unit cell and lattice parameters a=4.08771(1) Å, c=19.13087(8) Å. The compound displays mixed-valent manganese in a formal oxidation state close to +2.5 and powder neutron diffraction measurements reveal that below the Néel temperature of 63(1) K this results in an antiferromagnetic structure which may be described as A-type, modelled in the magnetic space group P{sub I}4/mnc (128.410 in the Belov, Neronova and Smirnova (BNS) scheme) inmore » which localised Mn moments of 3.99(2) μ{sub B} are arranged in ferromagnetic layers which are coupled antiferromagnetically. In contrast to the isostructural compound Sr{sub 2}MnO{sub 2}Cu{sub 1.5}S{sub 2}, Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} does not display long range ordering of coinage metal ions and vacancies, nor may significant amounts of the coinage metal readily be deintercalated using soft chemical methods. - Graphical abstract: Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} containing mixed valent Mn ions undergoes magnetic ordering with ferromagnetic coupling within MnO{sub 2} sheets and antiferromagnetic coupling between MnO{sub 2} sheets. - Highlights: • High purity sample of Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} obtained. • Magnetic structure determined. • Compared with related mixed-valent manganite oxide chalcogenides.« less

Real Time Spectroscopic Ellipsometry Analysis of First Stage CuIn1-xGaxSe₂ Growth: Indium-Gallium Selenide Co-Evaporation.

PubMed

Pradhan, Puja; Aryal, Puruswottam; Attygalle, Dinesh; Ibdah, Abdel-Rahman; Koirala, Prakash; Li, Jian; Bhandari, Khagendra P; Liyanage, Geethika K; Ellingson, Randy J; Heben, Michael J; Marsillac, Sylvain; Collins, Robert W; Podraza, Nikolas J

2018-01-16

Real time spectroscopic ellipsometry (RTSE) has been applied for in-situ monitoring of the first stage of copper indium-gallium diselenide (CIGS) thin film deposition by the three-stage co-evaporation process used for fabrication of high efficiency thin film photovoltaic (PV) devices. The first stage entails the growth of indium-gallium selenide (In 1- x Ga x )₂Se₃ (IGS) on a substrate of Mo-coated soda lime glass maintained at a temperature of 400 °C. This is a critical stage of CIGS deposition because a large fraction of the final film thickness is deposited, and as a result precise compositional control is desired in order to achieve the optimum performance of the resulting CIGS solar cell. RTSE is sensitive to monolayer level film growth processes and can provide accurate measurements of bulk and surface roughness layer thicknesses. These in turn enable accurate measurements of the bulk layer optical response in the form of the complex dielectric function ε = ε₁ - iε₂, spectra. Here, RTSE has been used to obtain the (ε₁, ε₂) spectra at the measurement temperature of 400 °C for IGS thin films of different Ga contents ( x ) deduced from different ranges of accumulated bulk layer thickness during the deposition process. Applying an analytical expression in common for each of the (ε₁, ε₂) spectra of these IGS films, oscillator parameters have been obtained in the best fits and these parameters in turn have been fitted with polynomials in x . From the resulting database of polynomial coefficients, the (ε₁, ε₂) spectra can be generated for any composition of IGS from the single parameter, x . The results have served as an RTSE fingerprint for IGS composition and have provided further structural information beyond simply thicknesses, for example information related to film density and grain size. The deduced IGS structural evolution and the (ε₁, ε₂) spectra have been interpreted as well in relation to observations from scanning

Use of technetium-99m methylene diphosphonate and gallium-67 citrate scans after intraarticular injection of Staphylococcus aureus into knee joints of rabbits with chronic antigen-induced arthritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahowald, M.L.; Raskind, J.R.; Peterson, L.

1986-08-01

Numerous clinical studies have questioned the ability of radionuclide scans to differentiate septic from aseptic joint inflammation. A clinical study may not be able to document an underlying disease process or duration of infection and, thus, may make conclusions about the accuracy of scan interpretations open to debate. In this study, the Dumonde-Glynn model of antigen-induced arthritis in rabbits was used as the experimental model to study technetium and gallium scans in Staphylococcus aureus infection of arthritic and normal joints. Gallium scans were negative in normal rabbits, usually negative in antigen-induced arthritis, but positive in septic arthritis. The bone scanmore » was usually negative in early infection but positive in late septic arthritis, a finding reflecting greater penetration of bacteria into subchondral bone because of the underlying inflammatory process.« less

Tc-99 Decontamination From Heat Treated Gaseous Diffusion Membrane -Phase I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L.; Wilmarth, B.; Restivo, M.

2017-03-13

Uranium gaseous diffusion cascades represent a significant environmental challenge to dismantle, containerize and dispose as low-level radioactive waste. Baseline technologies rely on manual manipulations involving direct access to technetium-contaminated piping and materials. There is a potential to utilize novel thermal decontamination technologies to remove the technetium and allow for on-site disposal of the very large uranium converters. Technetium entered these gaseous diffusion cascades as a hexafluoride complex in the same fashion as uranium. Technetium, as the isotope Tc-99, is an impurity that follows uranium in the first cycle of the Plutonium and Uranium Extraction (PUREX) process. The technetium speciation ormore » exact form in the gas diffusion cascades is not well defined. Several forms of Tc-99 compounds, mostly the fluorinated technetium compounds with varying degrees of volatility have been speculated by the scientific community to be present in these cascades. Therefore, there may be a possibility of using thermal desorption, which is independent of the technetium oxidation states, to perform an in situ removal of the technetium as a volatile species and trap the radionuclide on sorbent traps which could be disposed as low-level waste.« less

Design and characterization of α-melanotropin peptide analogs cyclized through rhenium and technetium metal coordination

PubMed Central

Giblin, Michael F.; Wang, Nannan; Hoffman, Timothy J.; Jurisson, Silvia S.; Quinn, Thomas P.

1998-01-01

α-Melanocyte stimulating hormone (α-MSH) analogs, cyclized through site-specific rhenium (Re) and technetium (Tc) metal coordination, were structurally characterized and analyzed for their abilities to bind α-MSH receptors present on melanoma cells and in tumor-bearing mice. Results from receptor-binding assays conducted with B16 F1 murine melanoma cells indicated that receptor-binding affinity was reduced to approximately 1% of its original levels after Re incorporation into the cyclic Cys4,10, d-Phe7–α-MSH4-13 analog. Structural analysis of the Re–peptide complex showed that the disulfide bond of the original peptide was replaced by thiolate–metal–thiolate cyclization. A comparison of the metal-bound and metal-free structures indicated that metal complexation dramatically altered the structure of the receptor-binding core sequence. Redesign of the metal binding site resulted in a second-generation Re–peptide complex (ReCCMSH) that displayed a receptor-binding affinity of 2.9 nM, 25-fold higher than the initial Re–α-MSH analog. Characterization of the second-generation Re–peptide complex indicated that the peptide was still cyclized through Re coordination, but the structure of the receptor-binding sequence was no longer constrained. The corresponding 99mTc- and 188ReCCMSH complexes were synthesized and shown to be stable in phosphate-buffered saline and to challenges from diethylenetriaminepentaacetic acid (DTPA) and free cysteine. In vivo, the 99mTcCCMSH complex exhibited significant tumor uptake and retention and was effective in imaging melanoma in a murine-tumor model system. Cyclization of α-MSH analogs via 99mTc and 188Re yields chemically stable and biologically active molecules with potential melanoma-imaging and therapeutic properties. PMID:9788997

The use of technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission CT scan in the follow-up of type II endoleak treatment.

PubMed

Nakai, Motoki; Sato, Hirotatsu; Ikoma, Akira; Sonomura, Tetsuo; Sato, Morio

2014-03-01

An 84-year-old woman presented with persistent type II endoleak with sac expansion from 57 mm to 75 mm during 4-year follow-up after endovascular abdominal aortic aneurysm repair. The patient underwent transabdominal embolization with coils and N-butyl cyanoacrylate/ethiodized oil (Lipiodol; Guerbet, Villepinte, France) mixture (2.5 mL). Because of the anticipated embolization artifacts on follow-up computed tomography (CT), technetium-99m-labeled human serum albumin diethylenetriamine pentaacetic acid single-photon emission computed tomography ((99m)Tc-HSAD SPECT) was performed before and after the intervention. Perigraft accumulation on (99m)Tc-HSAD SPECT corresponding to the endoleak disappeared after embolization. CT scan performed 12 months after embolization showed no signs of sac expansion. (99m)Tc-HSAD SPECT may be useful for evaluating therapeutic effect after embolization for endoleak. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

Behavior of technetium-99 in soils and plants. Final report, April 1, 1974--December 31, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gast, R.G.; Landa, E.R.; Thorvig, L.J.

Studies described in this report were aimed at establishing the magnitude and mechanisms of /sup 99/Tc sorption by soils and uptake by plants. Results show that /sup 99/Tc was sorbed from solution over a period to two to five weeks by 8 of 11 soils studies. The slow rate of sorption, the lack of sorption by low organic matter soils, the elimination of sorption following sterilization and increased sorption following addition of dextrose all point to a microbial role in the sorption process. However, it has not been established whether this is a direct or indirect role nor is itmore » possible to clearly predict the conditions under which sorption will occur. Results of plant uptake studies show that /sup 99/Tc can be taken up and translocated into the photosynthetic tissue of higher plants with concentrations in seeds being much less than in vegetative tissue. Technetium-99 was also shown to be toxic to plants at low concentrations and evidence suggests that this is a chemically rather than radiologically induced toxicity. However, this remains to be completely resolved as well as whether there is a threshold level of /sup 99/Tc required before toxicity occurs. Studies of short-term, dynamic, aerobic systems indicated that /sup 99/Tc moves through the soil as a relatively large anion exhibiting characteristic miscible displacement with some asymmetric tailing. /sup 99/Tc exhibits greater retention that C1/sup -/, which may be attributed statistically to weak complexion by organic matter. It is unlikely that this retention phenomenon is related to the static sorption activity reported in the first part of this study.« less

Effect of Thuya occidentalis on the labeling of red blood cells and plasma proteins with technetium-99m.

PubMed Central

Oliveira, J. F.; Braga, A. C.; Avila, A. S.; Fonseca, L. M.; Gutfilen, B.; Bernardo-Filho, M.

1996-01-01

Thuya occidentalis is used in popular medicine in the treatment of condyloma and has antibacterial action. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. This labeling depends on a reducing agent, usually stannous ion. Any drug which alters the labeling of the tracer could be expected to modify the disposition of the radiopharmaceutical. We have evaluated the influence of T. occidentalis extract on the labeling of RBC and plasma proteins with 99mTc. Blood was withdrawn and incubated with T. occidentalis (0.25; 2.5; 20.5; and 34.1 percent v/v). Stannous chloride (1.2 micrograms/ml) was added and then 99mTc was added. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) separated. The analysis of the results shows that there is a decrease in radioactivity (from 97.64 to 75.89 percent) in BC with 34.1 percent of the drug. In the labeling process of RBC with 99mTc, the stannous and pertechnetate ions pass through the membrane, so we suggest that the T. occidentalis effect can be explained (i) by an inhibition of the transport of these ions, (ii) by damage in membrane, (iii) by competition with the cited ions for the same binding sites, or (iv) by possible generation of reactive oxygen species that could oxidize the stannous ion. PMID:9436292

Effect of Thuya occidentalis on the labeling of red blood cells and plasma proteins with technetium-99m.

PubMed

Oliveira, J F; Braga, A C; Avila, A S; Fonseca, L M; Gutfilen, B; Bernardo-Filho, M

1996-01-01

Thuya occidentalis is used in popular medicine in the treatment of condyloma and has antibacterial action. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. This labeling depends on a reducing agent, usually stannous ion. Any drug which alters the labeling of the tracer could be expected to modify the disposition of the radiopharmaceutical. We have evaluated the influence of T. occidentalis extract on the labeling of RBC and plasma proteins with 99mTc. Blood was withdrawn and incubated with T. occidentalis (0.25; 2.5; 20.5; and 34.1 percent v/v). Stannous chloride (1.2 micrograms/ml) was added and then 99mTc was added. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) separated. The analysis of the results shows that there is a decrease in radioactivity (from 97.64 to 75.89 percent) in BC with 34.1 percent of the drug. In the labeling process of RBC with 99mTc, the stannous and pertechnetate ions pass through the membrane, so we suggest that the T. occidentalis effect can be explained (i) by an inhibition of the transport of these ions, (ii) by damage in membrane, (iii) by competition with the cited ions for the same binding sites, or (iv) by possible generation of reactive oxygen species that could oxidize the stannous ion.

From selenium- to tellurium-based glass optical fibers for infrared spectroscopies.

PubMed

Cui, Shuo; Chahal, Radwan; Boussard-Plédel, Catherine; Nazabal, Virginie; Doualan, Jean-Louis; Troles, Johann; Lucas, Jacques; Bureau, Bruno

2013-05-10

Chalcogenide glasses are based on sulfur, selenium and tellurium elements, and have been studied for several decades regarding different applications. Among them, selenide glasses exhibit excellent infrared transmission in the 1 to 15 µm region. Due to their good thermo-mechanical properties, these glasses could be easily shaped into optical devices such as lenses and optical fibers. During the past decade of research, selenide glass fibers have been proved to be suitable for infrared sensing in an original spectroscopic method named Fiber Evanescent Wave Spectroscopy (FEWS). FEWS has provided very nice and promising results, for example for medical diagnosis. Then, some sophisticated fibers, also based on selenide glasses, were developed: rare-earth doped fibers and microstructured fibers. In parallel, the study of telluride glasses, which can have transmission up to 28 µm due to its atom heaviness, has been intensified thanks to the DARWIN mission led by the European Space Agency (ESA). The development of telluride glass fiber enables a successful observation of CO₂ absorption band located around 15 µm. In this paper we review recent results obtained in the Glass and Ceramics Laboratory at Rennes on the development of selenide to telluride glass optical fibers, and their use for spectroscopy from the mid to the far infrared ranges.

Cyclopalladation of dimesityl selenide: synthesis, reactivity, structural characterization, isolation of an intermediate complex with C-H···Pd intra-molecular interaction and computational studies.

PubMed

Kolay, Siddhartha; Wadawale, Amey; Das, Dasarathi; Kisan, Hemanta K; Sunoj, Raghavan B; Jain, Vimal K

2013-08-14

The reaction of dimesityl selenide (Mes2Se) with either PdCl2(PhCN)2 in toluene or PdCl2 in toluene-acetonitrile yields a chloro-bridged binuclear palladium complex, [Pd2Cl2(μ-Cl)2(Mes2Se)2] (1), whereas with Na2PdCl4 in refluxing ethanol, a cyclometallated palladium complex, [Pd2(μ-Cl)2{MesSeC6H2(Me2)CH2}2] (2) is afforded. 2 can also be obtained when 1 is refluxed in ethanol. On treatment with Pb(Epy)2 in dichloromethane, 2 afforded the Epy-bridged binuclear complexes, [Pd2(μ-Epy)2{MesSeC6H2(Me2)CH2}2] (3; E = S (3a) or Se (3b)). Treatment of 2 with PPh3 yields a bridge-cleaved monomeric complex, [PdCl{MesSeC6H2(Me2)CH2}(PPh3)]. The molecular structures of 1-3 were established by X-ray diffraction analyses. All the complexes are dimeric, with the palladium atoms acquiring a distorted square planar configuration. There are intra-molecular C-H···Pd interactions (d(M-H): 2.75 Å and

Real-time gamma imaging of technetium transport through natural and engineered porous materials for radioactive waste disposal.

PubMed

Corkhill, Claire L; Bridge, Jonathan W; Chen, Xiaohui C; Hillel, Phil; Thornton, Steve F; Romero-Gonzalez, Maria E; Banwart, Steven A; Hyatt, Neil C

2013-12-03

We present a novel methodology for determining the transport of technetium-99m, a γ-emitting metastable isomer of (99)Tc, through quartz sand and porous media relevant to the disposal of nuclear waste in a geological disposal facility (GDF). Quartz sand is utilized as a model medium, and the applicability of the methodology to determine radionuclide transport in engineered backfill cement is explored using the UK GDF candidate backfill cement, Nirex Reference Vault Backfill (NRVB), in a model system. Two-dimensional distributions in (99m)Tc activity were collected at millimeter-resolution using decay-corrected gamma camera images. Pulse-inputs of ~20 MBq (99m)Tc were introduced into short (<10 cm) water-saturated columns at a constant flow of 0.33 mL min(-1). Changes in calibrated mass distribution of (99m)Tc at 30 s intervals, over a period of several hours, were quantified by spatial moments analysis. Transport parameters were fitted to the experimental data using a one-dimensional convection-dispersion equation, yielding transport properties for this radionuclide in a model GDF environment. These data demonstrate that (99)Tc in the pertechnetate form (Tc(VII)O4(-)) does not sorb to cement backfill during transport under model conditions, resulting in closely conservative transport behavior. This methodology represents a quantitative development of radiotracer imaging and offers the opportunity to conveniently and rapidly characterize transport of gamma-emitting isotopes in opaque media, relevant to the geological disposal of nuclear waste and potentially to a wide variety of other subsurface environments.

Real-Time Gamma Imaging of Technetium Transport through Natural and Engineered Porous Materials for Radioactive Waste Disposal

PubMed Central

2013-01-01

We present a novel methodology for determining the transport of technetium-99m, a γ-emitting metastable isomer of 99Tc, through quartz sand and porous media relevant to the disposal of nuclear waste in a geological disposal facility (GDF). Quartz sand is utilized as a model medium, and the applicability of the methodology to determine radionuclide transport in engineered backfill cement is explored using the UK GDF candidate backfill cement, Nirex Reference Vault Backfill (NRVB), in a model system. Two-dimensional distributions in 99mTc activity were collected at millimeter-resolution using decay-corrected gamma camera images. Pulse-inputs of ∼20 MBq 99mTc were introduced into short (<10 cm) water-saturated columns at a constant flow of 0.33 mL min–1. Changes in calibrated mass distribution of 99mTc at 30 s intervals, over a period of several hours, were quantified by spatial moments analysis. Transport parameters were fitted to the experimental data using a one-dimensional convection–dispersion equation, yielding transport properties for this radionuclide in a model GDF environment. These data demonstrate that 99Tc in the pertechnetate form (Tc(VII)O4–) does not sorb to cement backfill during transport under model conditions, resulting in closely conservative transport behavior. This methodology represents a quantitative development of radiotracer imaging and offers the opportunity to conveniently and rapidly characterize transport of gamma-emitting isotopes in opaque media, relevant to the geological disposal of nuclear waste and potentially to a wide variety of other subsurface environments. PMID:24147650

Radionuclide Sensors and Systems for Monitoring Technetium-99 and Strontium-90 in Groundwater at the Hanford Site

NASA Astrophysics Data System (ADS)

Grate, J. W.; O'Hara, M. J.; Egorov, O. B.; Burge, S. R.

2009-12-01

We have developed automated sensor and analyzer devices for detection and monitoring of trace radionuclides in water, using preconcentrating columns and radiometric detection. The preconcentrating minicolumn sensor concept combines selective capture and detection in a single functional unit, where the column contains tens to hundreds of milligrams of selectively sorbent material, and the entire column content is monitored with a radiometric detector. Compared to thin film sensors with a few microgram of sorbent, this approach achieves tremendous preconcentration with efficient mass transport via pumping. Furthermore, in an equilibration-based mode of operation, the preconcentration by the sensor is maximized while eliminating the need for consumable reagents to regenerate the column; it can simply be re-equilibrated. We have demonstrated quantification of radionuclides such as technetium-99 to levels below drinking water standards in an equilibration-based process that produces steady state signals, signal proportional to concentration, and easy re-equilibration to new concentration levels. Alternatively, analyzers can be developed with separate separation and detection units that are fluidically linked. We have demonstrated detection of strontium-90 to levels below drinking water standards by this approach. We are developing autonomous systems for at-site monitoring on the Hanford Site in Washington State, using the fluidic sensor and analyzer methods, with the aim of monitoring natural and accelerated attenuation processes, remediation and barrier performance, and contaminant fluxes in the environment. Figure 1. The strontium-90 monitoring method deployed as part of the Burge Environmental Universal Sensor Platform, shown on the shores of the Columbia River on the Hanford site in Washington State.

Mysteries of TOPSe revealed: insights into quantum dot nucleation.

PubMed

Evans, Christopher M; Evans, Meagan E; Krauss, Todd D

2010-08-18

We have investigated the reaction mechanism responsible for QD nucleation using optical absorption and nuclear magnetic resonance spectroscopies. For typical II-VI and IV-VI quantum dot (QD) syntheses, pure tertiary phosphine selenide sources (e.g., trioctylphosphine selenide (TOPSe)) were surprisingly found to be unreactive with metal carboxylates and incapable of yielding QDs. Rather, small quantities of secondary phosphines, which are impurities in tertiary phosphines, are entirely responsible for the nucleation of QDs; their low concentrations account for poor synthetic conversion yields. QD yields increase to nearly quantitative levels when replacing TOPSe with a stoiciometric amount of a secondary phosphine chalcogenide such as diphenylphosphine selenide. Based on our observations, we have proposed potential monomer identities, reaction pathways, and transition states and believe this mechanism to be universal to all II-VI and IV-VI QDs synthesized using phosphine based methods.

Mysteries of TOPSe Revealed: Insights into Quantum Dot Nucleation

PubMed Central

Evans, Christopher M.; Evans, Meagan E.

2010-01-01

We have investigated the reaction mechanism responsible for QD nucleation using optical absorption and nuclear magnetic resonance spectroscopies. For typical II-VI and IV-VI quantum dot (QD) syntheses, pure tertiary phosphine selenide sources (e.g. trioctylphosphine selenide (TOPSe)) were surprisingly found to be unreactive with metal carboxylates and incapable of yielding QDs. Rather, small quantities of secondary phosphines, which are impurities in tertiary phosphines, are entirely responsible for the nucleation of QDs; their low concentrations account for poor synthetic conversion yields. QD yields increase to nearly quantitative levels when replacing TOPSe with a stoiciometric amount of a secondary phosphine chalcogenide such as diphenylphosphine selenide. Based on our observations, we have proposed potential monomer identities, reaction pathways and transition states, and believe this mechanism to be universal to all II-VI and IV-VI QDs synthesized using phosphine based methods. PMID:20698646

Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

NASA Astrophysics Data System (ADS)

Burghoorn, M.; Kniknie, B.; van Deelen, J.; Xu, M.; Vroon, Z.; van Ee, R.; van de Belt, R.; Buskens, P.

2014-12-01

Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS) of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

Synthesis, crystal structure, and magnetic properties of quaternary iron selenides: Ba{sub 2}FePnSe{sub 5} (Pn=Sb, Bi)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian; Greenfield, Joshua T.; Kovnir, Kirill

Two new barium iron pnictide–selenides, Ba{sub 2}FeSbSe{sub 5} and Ba{sub 2}FeBiSe{sub 5}, were synthesized by a high-temperature solid-state route and their crystal structures were determined using single crystal X-ray diffraction. Both compounds are isomorphic to the high pressure phase Ba{sub 3}FeS{sub 5} and crystallize in the orthorhombic space group Pnma (No. 62) with cell parameters of a=12.603(2)/12.619(2) Å, b=9.106(1)/9.183(1) Å, c=9.145(1)/9.123(1) Å and Z=4 for Ba{sub 2}FeSbSe{sub 5} and Ba{sub 2}FeBiSe{sub 5}, respectively. According to differential scanning calorimetry, Ba{sub 2}FePnSe{sub 5} compounds exhibit high thermal stability and melt congruently at 1055(5) K (Pn=Sb) and 1105(5) K (Pn=Bi). Magnetic characterizations revealmore » strong antiferromagnetic nearest-neighbor interactions in both compounds resulting in an antiferromagnetic ordering at 58(1) K for Ba{sub 2}FeSbSe{sub 5} and 79(2) K for Ba{sub 2}FeBiSe{sub 5}. The magnetic interactions between Fe{sup 3+} centers, which are at least 6 Å apart from each other, are mediated by superexchange interactions. - Graphical abstract: In Ba{sub 2}FeSbSe{sub 5} and Ba{sub 2}FeBiSe{sub 5} the magnetic interactions between Fe{sup 3+} centers, which are at least 6 Å apart from each other, are mediated by superexchange interactions. - Highlights: • New compounds Ba{sub 2}FeSbSe{sub 5} and Ba{sub 2}FeBiSe{sub 5} have been synthesized. • The crystal structure was determined by single crystal X-ray diffraction. • Both compounds melt congruently at temperatures above 1000 K. • Ba{sub 2}FeSbSe{sub 5} and Ba{sub 2}FeBiSe{sub 5} exhibit AFM ordering at 58 K (Sb) and 70 K (Bi). • Magnetic exchange between Fe{sup 3+} is mediated by either Se–Sb(Bi)–Se or Se–Ba–Se bridges.« less

Visible optical isolator using ZnSe

NASA Technical Reports Server (NTRS)

Wunderlich, J. A.; Deshazer, L. G.

1977-01-01

A compact Faraday effect optical isolator was constructed for visible wavelengths and tested at 5145 A. The nonreciprocal element of the isolator was polycrystalline zinc selenide placed in the magnetic field of a permanent magnet. For 5145 A the isolator had a 2.06-dB insertion loss and a 25.5-dB isolation. Indices of refraction and Verdet constants were measured for zinc selenide in the wavelength region from 4700 to 6300 A.

Measurement of translymphatic fluid absorption using technetium-99m human serum albumin diethylenetriamine pentaacetic acid in continuous ambulatory peritoneal dialysis patients.

PubMed

Terawaki, Hiroyuki; Nakayama, Masaaki; Seto, Kazuhiko; Yoshimura, Kazunobu; Hasegawa, Toshio

2004-08-01

We have established a new method of measuring translymphatic fluid absorption (TLA) using technetium-99m ((99m)Tc) human serum albumin diethylenetriamine pentaacetic acid ((99m)Tc-HSAD) that can be used commonly in clinical practice. This new method was applied in 13 continuous ambulatory peritoneal dialysis patients (11 males and two females) who had various peritoneal permeability and capacities for peritoneal transport of water. (99m)Tc-HSAD 740MBq was injected in 2 L of peritoneal dialysis fluid with 2.5% glucose, mixed well, and administered intraperitoneally. The fluid was drained extraperitoneally after 4 h and TLA was determined by the in vivo loss of (99m)Tc-HSAD. TLA was 1.41 +/- 1.11 mL/min (mean +/- SD; range, 0.27-3.69 mL/min). The estimated reduction rate by TLA in trans-peritoneally removed fluid ranged from 14.2 to 84.4%, indicating that TLA could have an extremely significant negative effect in some cases on total drainage volume. The present study, using new tracer (99m)Tc-HSAD, could confirm a large individual difference in TLA, indicating TLA as an important contributing factor for fluid-removal failure in continuous ambulatory peritoneal dialysis patients.

Technetium-99m sestamibi scintimammography complements mammography in the detection of breast cancer.

PubMed

Krishnaiah, Gayathri; Sher-Ahmed, Arifa; Ugwu-Dike, Martins; Regan, Patricia; Singer, John; Totoonchie, Adil; Spiegler, Ethan; Sardi, Armando

2003-01-01

Mammography remains the technique of choice for the detection of early breast cancer. The sensitivity of mammography is 85%, but is decreased in patients with dense breasts. Sestamibi scintimammography (SCM) has been suggested as an adjunctive modality to improve the detection of breast cancer. We conducted a study to determine the impact of SCM in patient management. A prospective study was conducted in 95 patients presenting with palpable masses and/or abnormal mammography scheduled for biopsy. Injection of 20-30 mCi of technetium-99m (Tc-99m) sestamibi into a pedal vein was performed. Ten-minute images of the breast and axilla were obtained in multiple projections. The mammography and SCM were correlated with pathology and clinical findings. The median age was 44 years (range 28-86 years). The total number of lesions was 104, as eight patients had bilateral lesions and one patient had two lesions in the same breast. Fifty-nine patients presented with palpable lesions and 45 patients with nonpalpable lesions (42 with abnormal mammography only and 3 with nipple discharge). A comparison of sensitivity, specificity, positive and negative predictive values, and overall accuracy of SCM and mammography were performed. The sensitivity and specificity for SCM were 83% and 83%, respectively, and for mammography were 65%, and 72%, respectively. The sensitivity and specificity for combined SCM and mammography were 87% and 94%, respectively. The p-value for mammography versus combined SCM and mammography was 0.0003 and that for SCM versus SCM and mammography was 0.0098. There were 80 (77%) benign and 24 (23%) malignant lesions. Of the 24 malignancies, SCM missed six (25%), versus eight (33%) by mammography. In two patients (9%) SCM detected malignancy in the breast that was not visualized by mammography or found on clinical examination. Sestamibi SCM improves the sensitivity of mammography and it detects up to 9% of malignancies not detected by mammography or clinical

Technetium-99 cycling in maple trees: characterization of changes in chemical form.

PubMed

Garten, C T; Lomax, R D

1989-08-01

Prior field studies near an old radioactive waste disposal site at Oak Ridge, TN, indicated that following root uptake, metabolism by deciduous trees rendered 99Tc less biogeochemically mobile than expected, based on chemistry of the pertechnetate (TcO-4) anion. Subsequently, the form of technetium (Tc) in maple tree (Acer sp.) sap, leaves, wood and forest leaf litter was characterized using one or more of the following methods: dialysis, physical fractionation, chemical extraction, gel permeation chromatography, enzymatic extraction, or thin layer chromatography (TLC) on silica gel. Chromatography (Sephadex G-25) of TcO-4 incubated in vitro with tree sap showed it to behave similar to TcO-4 anion. When labeled wood and leaf tissues were processed using a tissue homogenizer, 15% and 40%, respectively, of the Tc was solubilized into phosphate buffer. Most (65% to 80%) of the solubilized Tc passing a 0.45-micron filter also passed through an ultrafiltration membrane with a nominal molecular weight cutoff of 10,000 atomic mass units (amu). A majority (72% to 80%) of the Tc in wood could be chemically removed by successive extractions with ethanol, water and weak mineral acid. These same extractants removed only 23% to 31% of the Tc from maple leaves or forest floor leaf litter. Most of the Tc in leaves and leaf litter was removed only by strongly alkaline reagents typically used to release structural polysaccharides (hemicelluloses) from plant tissues. Chromatography (Sephadex G-25) of the ethanol-water extract from wood and the alkaline extract from leaves demonstrated that Tc in these extracts was not principally TcO-4 but was complexed with molecules greater than 1000 amu. Incubations of leaf and wood homogenates with protease approximately doubled the amount of Tc released from contaminated tissues. Ultrafiltration of protease-solubilized Tc from leaves and wood showed that 40% and 93%, respectively, of the Tc was less than 10,000 amu. TLC of the less than 10

Full four-component relativistic calculations of the one-bond 77Se-13C spin-spin coupling constants in the series of selenium heterocycles and their parent open-chain selenides.

PubMed

Rusakov, Yury Yu; Rusakova, Irina L; Krivdin, Leonid B

2014-05-01

Four-component relativistic calculations of (77)Se-(13)C spin-spin coupling constants have been performed in the series of selenium heterocycles and their parent open-chain selenides. It has been found that relativistic effects play an essential role in the selenium-carbon coupling mechanism and could result in a contribution of as much as 15-25% of the total values of the one-bond selenium-carbon spin-spin coupling constants. In the overall contribution of the relativistic effects to the total values of (1)J(Se,C), the scalar relativistic corrections (negative in sign) by far dominate over the spin-orbit ones (positive in sign), the latter being of less than 5%, as compared to the former (ca 20%). A combination of nonrelativistic second-order polarization propagator approach (CC2) with the four-component relativistic density functional theory scheme is recommended as a versatile tool for the calculation of (1)J(Se,C). Solvent effects in the values of (1)J(Se,C) calculated within the polarizable continuum model for the solvents with different dielectric constants (ε 2.2-78.4) are next to negligible decreasing negative (1)J(Se,C) in absolute value by only about 1 Hz. The use of the locally dense basis set approach applied herewith for the calculation of (77)Se-(13)C spin-spin coupling constants is fully justified resulting in a dramatic decrease in computational cost with only 0.1-0.2-Hz loss of accuracy. Copyright © 2014 John Wiley & Sons, Ltd.

Research support for cadmium telluride crystal growth

NASA Technical Reports Server (NTRS)

Rosenberger, Franz

1995-01-01

The growth of single crystals of zinc selenide was carried out by both closed ampoule physical vapor transport and effusive ampoule physical vapor transport (EAPVT). The latter technique was shown to be a much more efficient method for the seeded growth of zinc selenide, resulting in higher transport rates. Furthermore, EAPVT work on CdTe has shown that growth onto (n 11) seeds is advantageous for obtaining reduced twinning and defect densities in II-VI sphalerite materials.

Diode-Pumped, 2-Micron, Q-Switched Thulium: Y3Al5O12 (Tm:Yag) Microchip Laser

DTIC Science & Technology

2011-05-01

switch with a chromium -doped zinc selenide crystal acting as a saturable absorber passive Q-switch. Finally, we will propose possible future...literature by Heine and Huber [4] and others, while passive Q-switching of 2 μm lasers by a chromium -doped zinc selenide has been demonstrated by Tsai and...these objectives for each component of the laser system. In Chapter 4 a design is presented for replacing our acousto-optic Q-switch with a chromium

When one becomes two: Ba12In4Se20, not quite isostructural to Ba12In4S19

NASA Astrophysics Data System (ADS)

Yin, Wenlong; Iyer, Abishek K.; Li, Chao; Yao, Jiyong; Mar, Arthur

2017-09-01

The ternary selenide Ba12In4Se20 was synthesized by reaction of BaSe, In2Se3, and Se at 1023 K. Single-crystal X-ray diffraction revealed a trigonal structure (space group R 3 bar, Z = 6, a = 10.0360(6) Å, c = 78.286(4) Å at room temperature) consisting of one-dimensional stacks of InSe4 tetrahedra, In2Se7 double tetrahedra, selenide Se2- anions, and diselenide Se22- anions, with Ba2+ cations in the intervening spaces. The selenide Ba12In4Se20 can be derived from the corresponding sulfide Ba12In4S19 by replacing one monoatomic Ch2- anion with a diatomic Ch22- anion. An optical band gap of 1.70(2) eV, consistent with the dark red colour of the crystals, was deduced from the UV-vis-NIR diffuse reflectance spectrum.

Controlling Growth High Uniformity Indium Selenide (In2Se3) Nanowires via the Rapid Thermal Annealing Process at Low Temperature.

PubMed

Hsu, Ya-Chu; Hung, Yu-Chen; Wang, Chiu-Yen

2017-09-15

High uniformity Au-catalyzed indium selenide (In 2 Se 3) nanowires are grown with the rapid thermal annealing (RTA) treatment via the vapor-liquid-solid (VLS) mechanism. The diameters of Au-catalyzed In 2 Se 3 nanowires could be controlled with varied thicknesses of Au films, and the uniformity of nanowires is improved via a fast pre-annealing rate, 100 °C/s. Comparing with the slower heating rate, 0.1 °C/s, the average diameters and distributions (standard deviation, SD) of In 2 Se 3 nanowires with and without the RTA process are 97.14 ± 22.95 nm (23.63%) and 119.06 ± 48.75 nm (40.95%), respectively. The in situ annealing TEM is used to study the effect of heating rate on the formation of Au nanoparticles from the as-deposited Au film. The results demonstrate that the average diameters and distributions of Au nanoparticles with and without the RTA process are 19.84 ± 5.96 nm (30.00%) and about 22.06 ± 9.00 nm (40.80%), respectively. It proves that the diameter size, distribution, and uniformity of Au-catalyzed In 2 Se 3 nanowires are reduced and improved via the RTA pre-treated. The systemic study could help to control the size distribution of other nanomaterials through tuning the annealing rate, temperatures of precursor, and growth substrate to control the size distribution of other nanomaterials. Graphical Abstract Rapid thermal annealing (RTA) process proved that it can uniform the size distribution of Au nanoparticles, and then it can be used to grow the high uniformity Au-catalyzed In 2 Se 3 nanowires via the vapor-liquid-solid (VLS) mechanism. Comparing with the general growth condition, the heating rate is slow, 0.1 °C/s, and the growth temperature is a relatively high growth temperature, > 650 °C. RTA pre-treated growth substrate can form smaller and uniform Au nanoparticles to react with the In 2 Se 3 vapor and produce the high uniformity In 2 Se 3 nanowires. The in situ annealing TEM is used to realize the effect of heating

Effects of positive expiratory pressure on pulmonary clearance of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid in healthy individuals

PubMed Central

de Albuquerque, Isabella Martins; Cardoso, Dannuey Machado; Masiero, Paulo Ricardo; Paiva, Dulciane Nunes; Resqueti, Vanessa Regiane; Fregonezi, Guilherme Augusto de Freitas; Menna-Barreto, Sérgio Saldanha

2016-01-01

ABSTRACT Objective: To evaluate the effects of positive expiratory pressure (PEP) on pulmonary epithelial membrane permeability in healthy subjects. Methods: We evaluated a cohort of 30 healthy subjects (15 males and 15 females) with a mean age of 28.3 ± 5.4 years, a mean FEV1/FVC ratio of 0.89 ± 0.14, and a mean FEV1 of 98.5 ± 13.1% of predicted. Subjects underwent technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) radioaerosol inhalation lung scintigraphy in two stages: during spontaneous breathing; and while breathing through a PEP mask at one of three PEP levels-10 cmH2O (n = 10), 15 cmH2O (n = 10), and 20 cmH2O (n = 10). The 99mTc-DTPA was nebulized for 3 min, and its clearance was recorded by scintigraphy over a 30-min period during spontaneous breathing and over a 30-min period during breathing through a PEP mask. Results: The pulmonary clearance of 99mTc-DTPA was significantly shorter when PEP was applied-at 10 cmH2O (p = 0.044), 15 cmH2O (p = 0.044), and 20 cmH2O (p = 0.004)-in comparison with that observed during spontaneous breathing. Conclusions: Our findings indicate that PEP, at the levels tested, is able to induce an increase in pulmonary epithelial membrane permeability and lung volume in healthy subjects. PMID:28117469

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

PubMed

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

99m Technetium-methylene diphosphonate ( 99m Tc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99m Tc-MDP-bone scan images. A set of 89 low contrast 99m Tc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t -test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful.

Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burghoorn, M.; Kniknie, B.; Deelen, J. van

2014-12-15

Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (J{sub sc}) and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-)selenide (CIGS) solar cells is also optically advantageous. Here, we experimentally demonstrate that the J{sub sc} and efficiency ofmore » CIGS solar cells with an absorber layer thickness (d{sub CIGS}) of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (n{sub resist} = 1.792 vs. n{sub AZO} = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, J{sub sc} increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%). No trend towards a larger relative increase in J{sub sc} with decreasing d{sub CIGS} was observed. Ergo, the increase in J{sub sc} can be fully explained by the reduction in reflection, and we did not observe any increase in J{sub sc} based on an increased photon path length.« less

Process for preparing radiopharmaceuticals

DOEpatents

Barak, Morton; Winchell, Harry S.

1977-01-04

A process for the preparation of technetium-99m labeled pharmaceuticals is disclosed. The process comprises initially isolating technetium-99m pertechnetate by adsorption upon an adsorbent packing in a chromatographic column. The technetium-99m is then eluted from the packing with a biological compound to form a radiopharmaceutical.

Electronic Characterization of Defects in Narrow Gap Semiconductors-Comparison of Electronic Energy Levels and Formation Energies in Mercury Cadmium Telluride, Mercury Zinc Telluride, and Mercury Zinc Selenide

NASA Technical Reports Server (NTRS)

Patterson, James D.

1996-01-01

We have used a Green's function technique to calculate the energy levels and formation energy of deep defects in the narrow gap semiconductors mercury cadmium telluride (MCT), mercury zinc telluride (MZT) and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total energy with an impurity cluster and the total energy for the perfect crystal. Substitutional (including antisite), interstitial (self and foreign), and vacancy deep defects are considered. Relaxation effects are calculated (with molecular dynamics). By use of a pseudopotential, we generalize the ideal vacancy model so as to be able to consider relaxation for vacancies. Different charge states are considered and the charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that due to relaxation. Different charged states for vacancies were not calculated to have much effect on the formation energy. For all cases we find deep defects in the energy gap only for cation site s-like orbitals or anion site p-like orbitals, and for the substitutional case only the latter are appreciably effected by relaxation. For most cases for MCT, MZT, MZS, we consider x (the concentration of Cd or Zn) in the range appropriate for a band gap of 0.1 eV. For defect energy levels, the absolute accuracy of our results is limited, but the precision is good, and hence chemical trends are accurately predicted. For the same reason, defect formation energies are more accurately predicted than energy level position. We attempt, in Appendix B, to calculate vacancy formation energies using relatively simple chemical bonding ideas due to Harrison. However, these results are only marginally accurate for estimating vacancy binding energies. Appendix C lists all written reports and publications produced for the grant. We include abstracts and a complete paper that summarizes our work which is not yet available.

Computational Investigation of Technetium(IV) Incorporation into Inverse Spinels: Magnetite (Fe 3 O 4 ) and Trevorite (NiFe 2 O 4 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Frances N.; Um, Wooyong; Taylor, Christopher D.

2016-05-17

Iron oxides and oxyhydroxides play an important role in minimizing the mobility of redox-sensitive elements in engineered and natural environments. For the radionuclide technetium-99 (Tc), these phases hold promise as primary hosts for increasing Tc loading into glass waste form matrices, or as secondary sinks during the long-term storage of nuclear materials. Recent experiments show that the inverse spinel, magnetite [Fe(II)Fe(III)2O4], can incorporate Tc(IV) into its octahedral sub-lattice, and in that same class of materials, trevorite [Ni(II)Fe(III)2O4] is also being investigated for its ability to host Tc(IV). However, questions remain regarding the most energetically favorable charge-compensation mechanism for Tc(IV) incorporationmore » in each structure, which will affect Tc behavior under changing waste processing or storage conditions. Here, quantum-mechanical methods were used to evaluate incorporation energies and optimized lattice bonding environments for three different, charge-balanced Tc(IV) incorporation mechanisms in magnetite and trevorite. In both cases, the removal of two octahedral Fe(II) or Ni(II) ions upon the addition of Tc(IV) to an octahedral site is the most stable mechanism, relative to the creation of octahedral Fe(III) defects or increasing octahedral Fe(II) content. Following hydration-energy corrections, Tc(IV) incorporation into magnetite is energetically favorable while an energy barrier exists for trevorite.« less

Examination of Technetium Transport Through Soils Under Contrasting Redox Conditions: Batch and Column Work

NASA Astrophysics Data System (ADS)

Dozier, R.; Montgomery, D.; Wylie, E. M.; Dogan, M.; Moysey, S. M.; Powell, B. A.; Martinez, N. E.

2015-12-01

Experiments were performed under various reducing conditions to evaluate the transport behavior of technetium-99 (99Tc) in the presence of sandy clay loam soil from the Savannah River Site (SRS) and goethite, magnetite, and iron sulfide, which were selected for their increasing reducing potential. The experiments were conducted to investigate how redox reaction equilibria and rates affect the overall mobility of 99Tc as it transitions between the mobile Tc(VII) and immobile Tc(IV). Under oxygen-rich conditions, batch sorption isotherms measured for TcO4- across the concentration range 0.5 to 50 μg/L were linear with distribution coefficients (Kd) of 0.78 mL/g or lower, with decreasing sorption for goethite, magnetite, and iron sulfide, respectively. Addition of Na2S resulted in a marked increase in apparent 99Tc sorption to the solid phase, with Kd of 43 mL/g, 35 mL/g, and 29 mL/g, following the same mineral trend as previously. The increased Kd values are possibly due to reduction of Tc(VII) to Tc(IV), resulting in the formation of TcO2(s). SRS soil batch sorption isotherms measured for TcO4- across the same concentration range were also linear, with Kd of 0.7 mL/g for unadjusted pH, 5.1 mL/g for pH of around 6, and 6.7 mL/g for pH of around 4. Kinetic batch sorption tests showed less than 10% 99Tc sorption in an oxidizing environment and greater than 95% sorption in a reducing environment, with both reactions occurring on the order of minutes. In contrast, desorption experiments initiated by transferring the samples from a reducing environment (0.1% H2(g)/99.9% N2(g)) to atmospheric conditions resulted in a slow desorption step on the order of days. Column experiments conducted with the SRS sands indicate a retardation factor of 1.17 for 99Tc under oxygen rich conditions. Additional column experiments are being conducted to evaluate 99Tc transport dependencies on transitions between oxygen rich and poor conditions.

Technetium-99 conjugated with methylene diphosphonate inhibits receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis.

PubMed

Gong, Wei; Dou, Huan; Liu, Xianqin; Sun, Lingyun; Hou, Yayi

2012-10-01

1. In the present study, we investigated the effects of technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP), an agent used in radionuclide therapy, on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and explored the underlying mechanisms. 2. The murine macrophage cell line RAW264.7 and bone marrow-derived-macrophages from C57BL/6 mice (BMM) were used as models for osteoclastogenesis in vitro. The expression of some key factors in RANKL (50 ng/mL)-induced osteoclastogenesis in RAW264.7 cells was investigated by flow cytometry and real-time reverse transcription-polymerase chain reaction (RT-PCR). To detect multinucleated osteoclast formation, RAW264.7 cells were induced with RANKL for 4 days, whereas BMM were induced by 50 ng/mL RANKL and 20 ng/mL macrophage colony-stimulating factor for 7 days, before being stained with tartrate-resistant acid phosphatase. 3. Osteoclastogenesis was evaluated using the osteoclast markers CD51, matrix metalloproteinase (MMP)-9 and cathepsin K. At 0.01 μg/mL, (99)Tc-MDP significantly inhibited RANKL-induced osteoclastogenesis without any cytotoxicity. In addition, (99)Tc-MDP abolished the appearance of multinucleated osteoclasts. 4. Real-time RT-PCR analysis of transcription factor expression revealed that (99)Tc-MDP inhibited the expression of c-Fos and nuclear factor of activated T cells. In addition, (99)Tc-MDP inhibited the expression of the inflammatory factors interleukin (IL)-6, tumour necrosis factor-α and IL-1β. Finally, (99)Tc-MDP inhibited the activation of mitogen-activated protein kinases in RAW264.7 cells following RANKL stimulation. 5. In conclusion, (99)Tc-MDP possesses anti-osteoclastogenic activity against RANKL-induced osteoclast formation. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

Detection of occult pericardial hemorrhage early after open-heart surgery using technetium-99m red blood cell radionuclide ventriculography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bateman, T.M.; Czer, L.S.; Gray, R.J.

1984-11-01

Pericardial or mediastinal hemorrhage requiring reoperation occurs in 2% to 5% of patients, usually early (0 to 48 hours), after open-heart surgery. This hemorrhage may be occult, and resulting cardiac tamponade may easily be misinterpreted as ventricular dysfunction, common early postoperatively. In such cases, appropriate and timely intervention may not occur. Of 50 patients evaluated by technetium-99m red blood cell gated equilibrium radionuclide ventriculography (RNV) because of early postoperative cardiogenic shock of uncertain etiology, 17 had unique scintigraphic images suggestive of intrathoracic hemorrhage. Of these 17, 5 had a generalized halo of abnormal radioactivity surrounding small hyperdynamic right and leftmore » ventricles, 11 had localized regions of intense blood pool activity outside the cardiac chambers (two with compression of single chambers), and one demonstrated marked radionuclide activity in the right hemithorax (2000 ml of blood at reoperation). Twelve patients had exploratory reoperation for control of hemorrhage as a direct result of the scintigraphic findings, three were successfully treated with fresh frozen plasma and platelet infusions along with medical interventions to optimize cardiac performance, and two patients died in cardiogenic shock (presumed tamponade) without reoperation. In the 12 reoperated patients, all were confirmed to have active pericardial bleeding. Scintigraphic localization of abnormal blood pools within the pericardium corresponded to the sites at which active bleeding was witnessed at reoperation. The abnormal bleeding was etiologically related to the tamponade state, with marked improvement in hemodynamics after reoperation. Nine additional patients were reoperated for presumed tamponade after RNV revealed an exaggerated halo of photon deficiency surrounding the cardiac chambers.« less

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement

PubMed Central

Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

2017-01-01

Purpose of the Study: 99mTechnetium-methylene diphosphonate (99mTc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99mTc-MDP-bone scan images. Materials and Methods: A set of 89 low contrast 99mTc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. Results: This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t-test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. Conclusion: GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful. PMID:29142344

Sentinel Lymphadenectomy in Vulvar Cancer Using Near-Infrared Fluorescence From Indocyanine Green Compared With Technetium 99m Nanocolloid.

PubMed

Soergel, Philipp; Hertel, Hermann; Nacke, Anna Kaarina; Klapdor, Rüdiger; Derlin, Thorsten; Hillemanns, Peter

2017-05-01

Nowadays, sentinel diagnostic is performed using technetium 99m (Tc) nanocolloid as a radioactive marker and sometimes patent blue. In the last years, indocyanine green has been evaluated for sentinel diagnostic in different tumor entities. Indocyanine green is a fluorescent molecule that emits a light signal in the near-infrared band after excitation. Our study aimed to evaluate indocyanine green compared with the criterion-standard Tc-nanocolloid. We included patients with primary, unifocal vulvar cancer of less than 4 cm with clinically node-negative groins in this prospective trial. Sentinel diagnostic was carried out using Tc-nanocolloid, indocyanine green, and patent blue. We examined each groin for light signals from the near-infrared band, for radioactivity, and for blue staining. A sentinel lymph node was defined as a Tc-nanocolloid-positive lymph node. All sentinel lymph nodes and all additional blue or fluorescent lymph nodes were excised and tested and then sent for histologic examination. In all, 27 patients were included in whom we found 91 sentinel lymph nodes in 52 groins. All these lymph nodes were positive for indocyanine green, also giving a sensitivity of 100% (95% confidence interval [CI], 96.0%-100%) compared with Tc-nanocolloid. Eight additional lymph nodes showed indocyanine green fluorescence but no Tc positivity, so that the positive predictive value was 91.9% (95% confidence interval, 84.6%-96.5%). In 1 patient, a false-negative sentinel missed by all 3 modalities was found. Our results show that indocyanine green is a promising approach for inguinal sentinel identification in vulvar cancer with a similar sensitivity as radioactive Tc-nanocolloid and worth to be evaluated in further studies.

Cortical perfusion response to an electrical stimulation of the auditory nerve in profoundly deaf patients: study with technetium-99m hexamethylpropylene amine oxime single photon emission tomography.

PubMed

Le Scao, Y; Robier, A; Baulieu, J L; Beutter, P; Pourcelot, L

1992-01-01

Brain activation procedures associated with single photon emission tomography (SPET) have recently been developed in healthy controls and diseased patients in order to help in their diagnosis and treatment. We investigated the effects of a promontory test (PT) on the cerebral distribution of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) in 7 profoundly deaf patients, 6 PT+ and one PT-. The count variation in the temporal lobe was calculated on 6 coronal slices using the ratio (Rstimulation-Rdeprivation)/Rdeprivation where R = counts in the temporal lobe/whole-brain count. A count increase in the temporal lobe was observed in all patients and was higher in all patients with PT+ than in the patient with PT-. The problems of head positioning and resolution of the system were taken into account, and we considered that the maximal count increment was related to the auditory cortex response to the stimulus. Further clinical investigations with high-resolution systems have to be performed in order to validate this presurgery test in cochlear implant assessment.

Real Time Spectroscopic Ellipsometry Analysis of First Stage CuIn1−xGaxSe2 Growth: Indium-Gallium Selenide Co-Evaporation

PubMed Central

Pradhan, Puja; Aryal, Puruswottam; Attygalle, Dinesh; Ibdah, Abdel-Rahman; Koirala, Prakash; Li, Jian; Bhandari, Khagendra P.; Liyanage, Geethika K.; Ellingson, Randy J.; Heben, Michael J.; Marsillac, Sylvain; Collins, Robert W.; Podraza, Nikolas J.

2018-01-01

Real time spectroscopic ellipsometry (RTSE) has been applied for in-situ monitoring of the first stage of copper indium-gallium diselenide (CIGS) thin film deposition by the three-stage co-evaporation process used for fabrication of high efficiency thin film photovoltaic (PV) devices. The first stage entails the growth of indium-gallium selenide (In1−xGax)2Se3 (IGS) on a substrate of Mo-coated soda lime glass maintained at a temperature of 400 °C. This is a critical stage of CIGS deposition because a large fraction of the final film thickness is deposited, and as a result precise compositional control is desired in order to achieve the optimum performance of the resulting CIGS solar cell. RTSE is sensitive to monolayer level film growth processes and can provide accurate measurements of bulk and surface roughness layer thicknesses. These in turn enable accurate measurements of the bulk layer optical response in the form of the complex dielectric function ε = ε1 − iε2, spectra. Here, RTSE has been used to obtain the (ε1, ε2) spectra at the measurement temperature of 400 °C for IGS thin films of different Ga contents (x) deduced from different ranges of accumulated bulk layer thickness during the deposition process. Applying an analytical expression in common for each of the (ε1, ε2) spectra of these IGS films, oscillator parameters have been obtained in the best fits and these parameters in turn have been fitted with polynomials in x. From the resulting database of polynomial coefficients, the (ε1, ε2) spectra can be generated for any composition of IGS from the single parameter, x. The results have served as an RTSE fingerprint for IGS composition and have provided further structural information beyond simply thicknesses, for example information related to film density and grain size. The deduced IGS structural evolution and the (ε1, ε2) spectra have been interpreted as well in relation to observations from scanning electron microscopy, X

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lieske, T.R.; Sunderrajan, E.V.; Passamonte, P.M.

A patient with chronic eosinophilic pneumonia was evaluated using bronchoalveolar lavage, technetium-99m glucoheptonate, and transbronchial lung biopsy. Bronchoalveolar lavage revealed 43 percent eosinophils and correlated well with results of transbronchial lung biopsy. Technetium-99m glucoheptonate lung imaging demonstrated intense parenchymal uptake. After eight weeks of corticosteroid therapy, the bronchoalveolar lavage eosinophil population and the technetium-99m glucoheptonate uptake had returned to normal. We suggest that bronchoalveolar lavage, with transbronchial lung biopsy, is a less invasive way than open lung biopsy to diagnose chronic eosinophilic pneumonia. The mechanism of uptake of technetium-99m glucoheptonate in this disorder remains to be defined.

Structure of spin excitations in heavily electron-doped Li 0.8Fe 0.2ODFeSe superconductors

DOE PAGES

Pan, Bingying; Shen, Yao; Hu, Die; ...

2017-07-25

Heavily electron-doped iron-selenide high-transition-temperature (high-T c) superconductors, which have no hole Fermi pockets, but have a notably high T c, have challenged the prevailing s± pairing scenario originally proposed for iron pnictides containing both electron and hole pockets. The microscopic mechanism underlying the enhanced superconductivity in heavily electron-doped iron-selenide remains unclear. Here, we used neutron scattering to study the spin excitations of the heavily electron-doped iron-selenide material Li 0.8Fe 0.2ODFeSe (T c = 41 K). Our data revealed nearly ring-shaped magnetic resonant excitations surrounding (π, π) at ~21 meV. As the energy increased, the spin excitations assumed a diamond shape,more » and they dispersed outward until the energy reached ~60 meV and then inward at higher energies. The observed energy-dependent momentum structure and twisted dispersion of spin excitations near (π, π) are analogous to those of hole-doped cuprates in several aspects, thus implying that such spin excitations are essential for the remarkably high T c in these materials.« less

Large-area synthesis and photoelectric properties of few-layer MoSe2 on molybdenum foils

NASA Astrophysics Data System (ADS)

Wu, Zenghui; Tai, Guoan; Wang, Xufeng; Hu, Tingsong; Wang, Rui; Guo, Wanlin

2018-03-01

Compared with MoS2 and WS2, selenide analogs have narrower band gaps and higher electron mobilities, which make them more applicable to real electrical devices. In addition, few-layer metal selenides have higher electrical conductivity, carrier mobility and light absorption than the corresponding monolayers. However, the large-scale and high-quality growth of few-layer metal selenides remains a significant challenge. Here, we develop a facile method to grow large-area and highly crystalline few-layer MoSe2 by directly selenizing the Mo foil surface at 550 °C within 60 min under ambient pressure. The atomic layers were controllably grown with thicknesses between 3.4 and 6 nm, which just met the thickness range required for high-performance electrical devices. Furthermore, we fabricated a vertical p-n junction photodetector composed of few-layer MoSe2 and p-type silicon, achieving photoresponsivity higher by two orders of magnitude than that of the reported monolayer counterpart. This technique provides a feasible approach towards preparing other 2D transition metal dichalcogendes for device applications.

Technetium-99m-labeled rituximab for use as a specific tracer of sentinel lymph node biopsy: a translational research study.

PubMed

Wang, Xuejuan; Yang, Zhi; Lin, Baohe; Zhang, Yan; Zhai, Shizhen; Zhao, Qichao; Xie, Qing; Liu, Fei; Han, Xuedi; Li, Jinfeng; Ouyang, Tao

2016-06-21

We aimed to develop and translate a CD20-antigen-targeted radiopharmaceutical, Technetium-99 m-labeled (99mTc) rituximab, for sentinel lymph node (SLN) detection. 99mTc-rituximab was synthesized and tested for stability in human serum. The binding affinity to CD20 was evaluated in Raji cells by flow cytometric analysis. Biodistribution and sentinel node mapping were carried out in bal b/c mice. Eighty-five patients with breast cancer participated in this study. Dynamic sentinel lymphoscintigraphy was first assessed in 12 patients before planar lymphoscintigraphy was assessed in a larger cohort. All patients underwent sentinel lymph node biopsy (SLNB), followed by axillary lymph node dissection. The cell-binding study showed that 99mTc-rituximab possessed compatible affinity to human CD20. In the mechanism study, 99mTc-labeled anti-mouse CD20 monoclonal antibodies could bind to mouse CD20 and accumulate in the SLN with 2.62±1.25 % of the percentage of injected activity, which could be blocked by excessive unlabeled antibody. Low uptake of non-sentinel nodes and fast clearance from the injection site were observed in the mice. Sentinel nodes were identified in 82 of 85 breast cancer patients (96.5%) by lymphoscintigraphy and SLNB. The sensitivity, specificity, and accuracy were 96.8% (30/31), 100% (51/51), and 98.8% (81/82), respectively. 99mTc-rituximab, specifically binding to CD20, met most of the requirements of an ideal sentinel mapping agent for use in clinical settings.

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

PubMed Central

Dudhia, Jayesh; Becerra, Patricia; Valdés, Miguel A.; Neves, Francisco; Hartman, Neil G.; Smith, Roger K.W.

2015-01-01

Recent advances in the application of bone marrow mesenchymal stem cells (BMMSC) for the treatment of tendon and ligament injuries in the horse suggest improved outcome measures in both experimental and clinical studies. Although the BMMSC are implanted into the tendon lesion in large numbers (usually 10 - 20 million cells), only a relatively small number survive (<10%) although these can persist for up to 5 months after implantation. This appears to be a common observation in other species where BMMSC have been implanted into other tissues and it is important to understand when this loss occurs, how many survive the initial implantation process and whether the cells are cleared into other organs. Tracking the fate of the cells can be achieved by radiolabeling the BMMSC prior to implantation which allows non-invasive in vivo imaging of cell location and quantification of cell numbers. This protocol describes a cell labeling procedure that uses Technetium-99m (Tc-99m), and tracking of these cells following implantation into injured flexor tendons in horses. Tc-99m is a short-lived (t1/2 of 6.01 hr) isotope that emits gamma rays and can be internalized by cells in the presence of the lipophilic compound hexamethylpropyleneamine oxime (HMPAO). These properties make it ideal for use in nuclear medicine clinics for the diagnosis of many different diseases. The fate of the labeled cells can be followed in the short term (up to 36 hr) by gamma scintigraphy to quantify both the number of cells retained in the lesion and distribution of the cells into lungs, thyroid and other organs. This technique is adapted from the labeling of blood leukocytes and could be utilized to image implanted BMMSC in other organs. PMID:26709915

Influence of exercise on the distribution of technetium Tc 99m medronate following intra-articular injection in horses.

PubMed

Dulin, Jennifer A; Drost, W Tod; Phelps, Mitch A; Santschi, Elizabeth M; Menendez, Maria I; Bertone, Alicia L

2012-03-01

To determine the effects of exercise on the distribution and pharmacokinetics of technetium Tc 99m medronate ((99m)Tc-MDP) following intra-articular (IA) injection in horses. 5 horses. 1 antebrachiocarpal joint (ACJ)/horse was assigned to the exercised group (n = 5), and the contralateral ACJ was evaluated in the nonexercised group (5) after a minimum washout period of 7 days. Following IA injection of (99m)Tc-MDP (148 MBq), blood and scintigraphic images of the carpus were obtained at 5, 10, 15, 20, 25, 30, 45, 60, 90, 120, 240, 360, 480, 600, 720, and 1,440 minutes. Plasma and scintigraphic radioactivity were determined over time, and pharmacokinetic parameters were generated via noncompartmental and compartmental analyses. Each horse was monitored via physical and lameness examination and ACJ synovial fluid analysis before injection and at days 1, 2, 3, and 7. Lameness was not observed. Mean ± SD synovial fluid WBC count increased at day 1 (exercised, 721 ± 234 cells/μL; nonexercised, 948 ± 223 cells/μL), but returned to baseline at days 3 and 7 Mean time to maximum plasma radioactivity was earlier in the exercised group (16.00 ± 2.35 minutes) than the nonexercised group (43.75 ± 3.64 minutes). Linear regression of the scintigraphic radioactivity-time curves revealed a greater negative slope in the exercised group within the first 25 minutes. There was no difference in absorption or elimination rate constants in a 2-compartment model. IA injection of (99m)Tc-MDP was safe and effective for evaluating synovial solute distribution. Exercise significantly increased early transfer of (99m)Tc-MDP from the ACJ into plasma, although absorption and elimination rate constants were not affected. Exercise may affect synovial clearance and withdrawal times of medications administered IA.

Technetium-99 and strontium-90: Abundance determination at ultratrace sensitivity by AMS as signatures of undeclared nuclear reprocessing activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

McAninch, J.E.; Proctor, I.D.

1995-03-01

The purpose of this White Paper is to examine the use of the ultratrace technique Accelerator Mass Spectrometry (AMS) to lower detection limits for {sup 99}Tc and {sup 90}Sr, and to examine the utility of these isotopes as signatures of a convert reprocessing facility. The International Atomic Energy Agency (IAEA) has committed to improving the effectiveness of the IAEA Safeguards System. This is in some degree a result of the discovery in 1991 of an undeclared Iraqi EMIS program. Recommendations from the March 1993 Consultants Group Meeting have resulted in several studies and follow on field trials to identify environmentalmore » signatures from covert nuclear fuel reprocessing activity. In particular, the April, 1993 reports of the Standing Advisory Group on Safeguards Implementation (SAGSI) identified the long-lived radioisotopes Technetium-99 and strontium-90 as two reliable signatures of fuel reprocessing activity. This report also suggested pathways in the chemical processing of irradiated fuel where these elements would be volatilized and potentially released in amounts detectable with ultratrace sensitivity techniques. Based on measured {sup 99}Tc background levels compiled from a variety of sources, it is estimated that AMS can provide 10% measurements of environmental levels of {sup 99}Tc in a few minutes using modestly sized samples: a few grams for soils, plants, or animal tissues; one to several liters for rain or seawater samples; and tens to hundreds of cubic meters for air sampling. Small sample sizes and high sample throughput result in significant increases in feasibility, cost effectiveness, and quality of data for a regional monitoring program. Similar results are expected for {sup 90}Sr.« less

Technetium-99m thyroid scan; does it have a diagnostic aid in sub-clinical auto-immune thyroid disease in systemic lupus erythematosus patients?

PubMed

Amin, A; Alkemary, A; Abdo, M; Salama, M

2016-02-01

Technetium-99m (Tc-99m) thyroid scintigraphy is a well known diagnostic tool that shows the entire gland in a single image. We aimed to evaluate its additive diagnostic value in subclinical autoimmune thyroid disease (S-AITD) in systemic lupus erythematosus (SLE) patients. We investigated 100 systemic lupus erythematosus (SLE) patients without overt thyroid involvement (eight men and 92 women; mean age 40±6.5 years) and 50 age and sex matched controls. All were subjected to thyroid evaluation using anti-thyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO) antibodies; hormones (FT3; FT4 and TSH) and Tc-99m thyroid scintigraphy. 14/100 (14%) and none (0%) were positive for S-AITD in SLE and control groups, respectively (P = 0.0001). They were classified by thyroid scintigraphy and hormonal profile into 2/14 Hashimoto; 10/14 atrophic thyroiditis and 2/14 Graves' disease. Anti-TPO was elevated in 12 SLE cases, while anti-TG was elevated in only 2/14 (P = 0.0001). Thyroid scintigraphy showed statistically significant associations with FT4, TSH and anti-TPO. Tc-99m thyroid scintigraphy may have an additional diagnostic role in S-AITD among SLE patients, with an impact on patient management. This potential needs to be further evaluated in a larger series on a multicenter basis. © The Author(s) 2015.

Diagrams of the formation of In2S3 and In2Se3 films on vitroceramic upon precipitation, according to potentiometric titration

NASA Astrophysics Data System (ADS)

Tulenin, S. S.; Bakhteev, S. A.; Yusupov, R. A.; Maskaeva, L. N.; Markov, V. F.

2013-10-01

Boundary conditions and ranges of the formation of indium(III) sulfide and selenide upon precipitation by thiocarbamide and selenocarbamide are determined. Potentiometric titration of indium chloride (InCl3) in the concentration range of 0.0001 to 0.100 mol/L by a solution of sodium hydroxide is performed. It is found that the following pH ranges are optimal for In2S3 and In2Se3 film precipitation: from 3.0 to 4.5 and from 9.0 to 14.0. Indium selenide layers 100 to 300 nm thick are prepared on vitroceramic by hydrochemcial precipitation.

Determination of the mechanical properties of SnSe, a novel layered semiconductor

NASA Astrophysics Data System (ADS)

Lamuta, Caterina; Campi, Davide; Pagnotta, Leonardo; Dasadia, Abhay; Cupolillo, Anna; Politano, Antonio

2018-05-01

Tin selenide (SnSe) is one the most promising materials for flexible electronics. However, experiments on the direct determination of its mechanical properties are still missing. By means of depth-sensing nanoindentation experiments, we directly evaluate the Young's modulus of bulk single crystals of tin selenide (25.3 GPa), as well as their hardness (0.82 GPa). Experimental results are compared with predictions by density functional theory, performed using eleven different functionals. The discrepancies between the experimental results and the thoretical predictions can be ascribed to the oxidation of the SnSe surface, detected by X-ray photoelectron spectroscopy.

LABORATORY REPORT ON THE REMOVAL OF PERTECHNETATE FROM TANK 241-AN-105 SIMULANT USING PUROLITE A530E

DOE Office of Scientific and Technical Information (OSTI.GOV)

DUNCAN JB; HAGERTY KJ, MOORE WP; JOHNSON JM

2012-04-17

This report documents the laboratory testing and analyses as directed under the test plan, LAB-PLN-11-00010, Evaluation of Technetium Ion Exchange Material against Hanford Double Shell Tank Supernate Simulate with Pertechnetate. Technetium (Tc-99) is a major fission product from nuclear reactors, and because it has few applications outside of scientific research, most of the technetium will ultimately be disposed of as nuclear waste. The radioactive decay of Tc-99 to ruthenium 99 (Ru-99) produces a low energy {beta}{sup -} particle (0.1 MeV max). However, due to its fairly long half-life (t{sub 1/2} = 2.13E05 years), Tc-99 is a major source of radiationmore » in low-level waste (UCRL-JRNL-212334, Current Status of the Thermodynamic Data for Technetium and its Compounds and Aqueous Species). Technetium forms the soluble oxy anion, TcO{sub 4}{sup -} under aerobic conditions. This anion is very mobile in groundwater and poses a health risk (ANL, Radiological and Chemical Fact Sheets to Support Health Risk Analyses for Contaminated Areas). It has been demonstrated that Purolite{reg_sign} A530E is highly effective in removing TcO{sub 4}{sup -} from a water matrix (RPP-RPT-23199, The Removal of Technetium-99 from the Effluent Treatment Facility Basin 44 Waste Using Purolite A-530E, Reillex HPQ, and Sybron IONAC SR-7 Ion Exchange Resins). Purolite{reg_sign} A530E is the commercial product of the Oak Ridge National Laboratory's Biquat{trademark} resin (Gu, B. et. ai, Development of Novel Bifunctional Anion-Exchange Resins with Improved Selectivity for Pertechnetate Sorption from Contaminated Groundwater). Further work has demonstrated that technetium-loaded A530E achieves a leachability index in Cast Stone of 12.5 (ANSI/ASN-16.1-2003, Measurement of the Leachability of Solidified Low-Level Radioactive Wastes by a Short-term Test Procedure) as reported in RPP-RPT-39195, Assessment of Technetium Leachability in Cement-Stabilized Basin 43 Groundwater Brine. This effort

Comparison of indium-labeled-leukocyte imaging with sequential technetium-gallium scanning in the diagnosis of low-grade musculoskeletal sepsis. A prospective study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merkel, K.D.; Brown, M.L.; Dewanjee, M.K.

We prospectively compared sequential technetium-gallium imaging with indium-labeled-leukocyte imaging in fifty patients with suspected low-grade musculoskeletal sepsis. Adequate images and follow-up examinations were obtained for forty-two patients. The presence or absence of low-grade sepsis was confirmed by histological and bacteriological examinations of tissue specimens taken at surgery in thirty of the forty-two patients. In these thirty patients, the sensitivity of sequential Tc-Ga imaging was 48 per cent, the specificity was 86 per cent, and the accuracy was 57 per cent, whereas the sensitivity of the indium-labeled-leukocyte technique was 83 per cent, the specificity was 86 per cent, and the accuracymore » was 83 per cent. When the additional twelve patients for whom surgery was deemed unnecessary were considered, the sensitivity of sequential Tc-Ga imaging was 50 per cent, the specificity was 78 per cent, and the accuracy was 62 per cent, as compared with a sensitivity of 83 per cent, a specificity of 94 per cent, and an accuracy of 88 per cent with the indium-labeled-leukocyte method. In patients with a prosthesis the indium-labeled-leukocyte image was 94 per cent accurate, compared with 75 per cent accuracy for sequential Tc-Ga imaging. Statistical analysis of these data demonstrated that the indium-labeled-leukocyte technique was superior to sequential Tc-Ga imaging in detecting areas of low-grade musculoskeletal sepsis.« less

Thermodynamic and Microstructural Mechanisms in the Corrosion of Advanced Ceramic Tc-bearing Waste Forms and Thermophysical Properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartmann, Thomas

Technetium-99 (Tc, t 1/2 = 2.13x10 5 years) is a challenge from a nuclear waste perspective and is one of the most abundant, long-lived radioisotopes found in used nuclear fuel (UNF). Within the Hanford Tank Waste Treatment and Immobilization Plant, technetium volatilizes at typical glass melting temperature, is captured in the off-gas treatment system and recycled back into the feed to eventually increase Tc-loadings of the glass. The aim of this NEUP project was to provide an alternative strategy to immobilize fission technetium as durable ceramic waste form and also to avoid the accumulation of volatile technetium within the offmore » gas melter system in the course of vitrifying radioactive effluents in a ceramic melter. During this project our major attention was turned to the fabrication of chemical durable mineral phases where technetium is structurally bond entirely as tetravalent cation. These mineral phases will act as the primary waste form with optimal waste loading and superior resistance against leaching and corrosion. We have been very successful in fabricating phase-pure micro-gram amounts of lanthanide-technetium pyrochlores by dry-chemical synthesis. However, upscaling to a gram-size synthesis route using either dry- or wet-chemical processing was not always successful, but progress can be reported on a variety of aspects. During the course of this 5-year NEUP project (including a 2-year no-cost extension) we have significantly enhanced the existing knowledge on the fabrication and properties of ceramic technetium waste forms.« less

Significance of Technetium-99m Human Serum Albumin Diethylenetriamine Pentaacetic Acid Scintigraphy in Patients with Nephrotic Syndrome

PubMed Central

Takashima, Tsuyoshi; Kishi, Tomoya; Onozawa, Koji; Rikitake, Shuichi; Miyazono, Motoaki; Otsuka, Takateru; Irie, Hiroyuki; Iwakiri, Ryuichi; Fujimoto, Kazuma; Ikeda, Yuji

2015-01-01

It is thought that a large amount of albumin leaking from the glomerulus in nephrotic syndrome (NS) is reabsorbed at the proximal tubule and catabolized. Therefore, it is possible the final quantity of urinary protein does not always reflect the amount of leakage of protein from the glomerulus. We experienced two cases without nephrotic range proteinuria thought to involve hypoproteinemia due to the same pathophysiology as NS. On these patients, we performed protein leakage scintigraphy with technetium-99m human serum albumin diethylenetriamine pentaacetic acid (99mTc-HSAD) to exclude a diagnosis of protein-losing gastroenteropathy and observed diffuse positive accumulation in the kidneys with more intense uptake in the kidney than the liver on the anterior view 24 hours after 99mTc-HSAD administration. In healthy adults intravenously given 99mTc-HSAD, the same dynamics are observed as in albumin metabolism, and the organ radioactivity of the liver and kidneys after 24 hours is equal. Therefore, we thought it was possible that the renal uptake 24 hours after 99mTc-HSAD administration was a characteristic finding of NS. In order to confirm it, the subjects were divided into two groups: the NS group (n = 10) and the non-NS group (n = 7). We defined more intense uptake in the kidney than the liver on the anterior view 24 hours after 99mTc-HSAD administration as Dense Kidney (+). Furthermore, we designed regions of interest in the right and left kidneys and liver on anterior and posterior images, then calculated the kidney-liver ratio. Nine of the ten patients had Dense Kidney (+) in the NS group, compared to none in the non-NS group. And the kidney-liver ratio was significantly higher in the NS group than in the non-NS group on each view in the bilateral kidneys. In conclusion, our results suggest that the renal uptake 24 hours after 99mTc-HSAD administration is a characteristic finding of NS. PMID:25859658

Significance of technetium-99m human serum albumin diethylenetriamine pentaacetic acid scintigraphy in patients with nephrotic syndrome.

PubMed

Takashima, Tsuyoshi; Kishi, Tomoya; Onozawa, Koji; Rikitake, Shuichi; Miyazono, Motoaki; Otsuka, Takateru; Irie, Hiroyuki; Iwakiri, Ryuichi; Fujimoto, Kazuma; Ikeda, Yuji

2015-01-01

It is thought that a large amount of albumin leaking from the glomerulus in nephrotic syndrome (NS) is reabsorbed at the proximal tubule and catabolized. Therefore, it is possible the final quantity of urinary protein does not always reflect the amount of leakage of protein from the glomerulus. We experienced two cases without nephrotic range proteinuria thought to involve hypoproteinemia due to the same pathophysiology as NS. On these patients, we performed protein leakage scintigraphy with technetium-99m human serum albumin diethylenetriamine pentaacetic acid (99mTc-HSAD) to exclude a diagnosis of protein-losing gastroenteropathy and observed diffuse positive accumulation in the kidneys with more intense uptake in the kidney than the liver on the anterior view 24 hours after 99mTc-HSAD administration. In healthy adults intravenously given 99mTc-HSAD, the same dynamics are observed as in albumin metabolism, and the organ radioactivity of the liver and kidneys after 24 hours is equal. Therefore, we thought it was possible that the renal uptake 24 hours after 99mTc-HSAD administration was a characteristic finding of NS. In order to confirm it, the subjects were divided into two groups: the NS group (n = 10) and the non-NS group (n = 7). We defined more intense uptake in the kidney than the liver on the anterior view 24 hours after 99mTc-HSAD administration as Dense Kidney (+). Furthermore, we designed regions of interest in the right and left kidneys and liver on anterior and posterior images, then calculated the kidney-liver ratio. Nine of the ten patients had Dense Kidney (+) in the NS group, compared to none in the non-NS group. And the kidney-liver ratio was significantly higher in the NS group than in the non-NS group on each view in the bilateral kidneys. In conclusion, our results suggest that the renal uptake 24 hours after 99mTc-HSAD administration is a characteristic finding of NS.

An estimate of the inventory of technetium-99 in the sub-tidal sediments of the Irish Sea.

PubMed

Jenkinson, Stuart B; McCubbin, David; Kennedy, Paul H W; Dewar, Alastair; Bonfield, Rachel; Leonard, Kinson S

2014-07-01

Published results from earlier studies have provided indications that measurable quantities of technetium-99 ((99)Tc) have accumulated in the sub-tidal sediments of the Irish Sea. This is due to the enhanced discharges from the Sellafield nuclear reprocessing plant in Cumbria, UK (between 1994 and 2004). Depth distributions of (99)Tc concentrations in sub-tidal sediments have been determined from a limited number of Irish Sea sites, following the collection of deep sediment cores (up to 2 m in depth), sampled in two research cruise surveys in 2005 and 2006. Vertical concentration profiles of (99)Tc from a range of substrates in the Irish Sea are presented here and these have been used to produce an estimate of the total inventory of (99)Tc residing in the sub-tidal sediments of the Irish Sea. Significant variation was observed between (99)Tc concentrations in the sediment samples, as well as in the shape of individual depth profiles. As anticipated, concentrations tended to be greater on fine-grained (muddy) substrates and showed a general decrease with distance from Sellafield. Vertical concentration profiles of (137)Cs, and (137)Cs data from published work, have also been considered to evaluate the use of the relatively few (99)Tc core data (upon which to determine the (99)Tc inventory). The inventories of (99)Tc and (137)Cs are estimated to have been of the order of 30 and 455 terabecquerels (TBq), respectively, or ∼2% of the total cumulative Sellafield discharge for each of the two radionuclides. The residence half-time of (137)Cs in the sub-tidal sediments of the Irish Sea is estimated to be in the order of ∼16 years. Therefore, as the Kd values for (99)Tc and (137)Cs are similar, this also provides an indicative value to predict future losses of (99)Tc from the sediment reservoir. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Liver Function Assessment Using Technetium 99m-Galactosyl Single-Photon Emission Computed Tomography/CT Fusion Imaging: A Prospective Trial.

PubMed

Okabayashi, Takehiro; Shima, Yasuo; Morita, Sojiro; Shimada, Yasuhiro; Sumiyoshi, Tatsuaki; Sui, Kenta; Iwata, Jun; Iiyama, Tatsuo

2017-12-01

The prediction of postoperative liver function remains a largely subjective practice based on CT volumetric analysis. However, future liver volume after a hepatectomy is not the only factor that contributes to postoperative liver function and outcomes. In this prospective trial, 185 consecutive patients who underwent liver operations between 2014 and 2015 were studied. Volumetric and functional rates of remnant liver were measured using technetium 99m-galactosyl human serum albumin single-photon emission computed tomography/CT fusion imaging to evaluate post-hepatectomy remnant liver function. Remnant indocyanine green clearance rate using galactosyl (KGSA) (KGSA × functional rate) was used to predict future remnant liver function. Hepatectomy was considered safe for patients with remnant KGSA values ≥0.05, and the primary end point was to determine the accuracy and reliability of this criteria. The prediction of the 90-day major complication and mortality rates was assessed. Median hospital stay was 9 days and median ICU stay was 1 day, with only 1 in-hospital death (90-day mortality rate 0.5%). Overall morbidity rate evaluated according to the Clavien-Dindo classification was 9%. For post-hepatectomy liver failure definitions, the International Study Group of Liver Surgery definition was fulfilled in 14 patients (8%), with the majority being grade B (50%), compared with 2 patients (1%) fulfilling the "50-50" criteria, and 0 patients (0%) fulfilling the Peak Bili >7 criteria. Results of this study showed that remnant KGSA provided information that allowed us to predict remnant liver function. This information will be important for surgeons when deciding on a treatment plan for patients with liver diseases. (ClinicalTrials.gov ID: NCT02013895). Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Positioning irrigation of contrast cystography for diagnosis of occult vesicoureteric reflux: association with technetium-99m dimercaptosuccinic acid scans.

PubMed

Berger, Christoph; Becker, Tanja; Koen, Mark; Zeino, Mazen; Fitz, Friedrich; Beheshti, Mohsen; Wolf-Kohlmeier, Iris; Haim, Silke; Riccabona, Marcus

2013-12-01

Positioning irrigation of contrast (PIC) cystography identifies occult or PIC vesicoureteral reflux (PIC-VUR) in children with recurrent febrile urinary tract infections (UTI) but no vesicoureteric reflux (VUR) on standard voiding cystourethrogram (VCUG). We sought to identify the relationship between PIC-VUR and renal scarring in technetium-99m dimercaptosuccinic acid (DMSA) scans. We retrospectively analysed PIC cystograms and DMSA scans for 154 kidneys in 81 children (65 girls; 16 boys; median age, 4.7 years; range, 0.9-15.2). Renal scarring was graded on a scale of 0-3. DMSA scans were pathologic in 66 patients (81%). Children had experienced mean 3.8 febrile UTI (range 1-25). Forty-seven (58%) children had a history of reflux, including 15 (19%) with previous anti-reflux operations. Indications for PIC cystography were recurrence of febrile UTI after either bilateral negative VCUG (66 children) or unilateral VUR (15 children) with contralateral/bilateral scarring or reflux that had changed sides in subsequent VCUGs. PIC-VUR was bilateral in 63, unilateral in 12, and absent in 6 children. Statistically significant associations between PIC-VUR grade and severity of renal scarring were identified in inter-individual (n = 77, p = 0.017) and intra-individual (refluxing vs. nonrefluxing kidney; n = 12, p = 0.008) analyses. After excluding patients with history of VUR, statistical significance was maintained in inter-individual analysis (n = 49; p = 0.018). The data suggest an association between PIC-VUR and severity of renal scarring, and legitimise the use of PIC cystography in children with renal scarring due to recurrent febrile UTI but negative findings on VCUG. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Towards mid-infrared fiber-optic devices and systems for sensing, mapping and imaging

NASA Astrophysics Data System (ADS)

Jayasuriya, D.; Wilson, B.; Furniss, D.; Tang, Z.; Barney, E.; Benson, T. M.; Seddon, A. B.

2016-03-01

Novel chalcogenide glass-based fiber opens up the mid-infrared (MIR) range for real-time monitoring and control in medical diagnostics and chemical processing. Fibers with long wavelength cut-off are of interest here. Sulfide, selenide and telluride based chalcogenide glass are candidates, but there are differences in their glass forming region, thermal stability and in the short and long wavelength cut-off positions. In general sulfide and selenide glasses have greater glass stability, but shorter long-wavelength cut-off edge, compared to telluride glasses; selenide-telluride glasses are a good compromise. Low optical loss selenide-telluride based long wavelength fibers could play a substantial role in improving medical diagnostic systems, chemical sensing, and processing, and in security and agriculture. For biological tissue, the molecular finger print lies between ~3-15 μm wavelengths in the MIR region. Using MIR spectral mapping, information about diseased tissue may be obtained with improved accuracy and in vivo using bright broadband MIR super-continuum generation (SCG) fiber sources and low optical loss fiber for routing. The Ge-As-Se-Te chalcogenide glass system is a potential candidate for both MIR SCG and passive-routing fiber, with good thermal stability, wide intrinsic transparency from ~1.5 to 20 μm and low phonon energy. This paper investigates Ge-As-Se-Te glass system pairs for developing high numerical aperture (NA) small-core, step-index optical fiber for MIR SCG and low NA passive step-index optical fiber for an in vivo fiber probe. Control of fiber geometry of small-core optical fiber and methods of producing the glass material are also included in this paper.

Facile synthesis of CuSe nanoparticles and high-quality single-crystal two-dimensional hexagonal nanoplatelets with tunable near-infrared optical absorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yimin; Korolkov, Ilia; Qiao, Xvsheng

2016-06-15

A rapid injection approach is used to synthesize the copper selenide nanoparticles and two-dimensional single crystal nanoplates. This technique excludes the use of toxic or expensive materials, increasing the availability of two-dimensional binary chalcogenide semiconductors. The structure of the nanocrystals has been studied and the possible formation mechanism of the nanoplates has been proposed. The optical absorption showed that the nanoplates demonstrated wide and tuneable absorption band in the visible and near infrared region. These nanoplates could be interesting for converting solar energy and for nanophotonic devices operating in the near infrared. - Graphical abstract: TEM images of the coppermore » selenides nanoparticles and nanoplates synthesized at 180 °C for 0 min, 10 min, 60 min. And the growth mechanism of the copper selenide nanoplates via the “oriented attachment”. Display Omitted - Highlights: • CuSe nanoparticles and nanoplates are synthesized by a rapid injection approach. • CuSe band gap can be widely tuned simply by modifying the synthesized time. • Al{sup 3+} ions have a significant impact on the growth rate of the nanoplates. • Growth mechanism of the CuSe nanoplates is based on the “oriented attachment”.« less

Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs.

PubMed

Shiel, R E; Pinilla, M; McAllister, H; Mooney, C T

2012-05-01

To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non-thyroidal illnesses. Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism. In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non-thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary-dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non-diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non-thyroidal illness was identified in both cases. In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non-diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function. © 2012 British Small Animal Veterinary Association.

Solid-state framing camera with multiple time frames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, K. L.; Stewart, R. E.; Steele, P. T.

2013-10-07

A high speed solid-state framing camera has been developed which can operate over a wide range of photon energies. This camera measures the two-dimensional spatial profile of the flux incident on a cadmium selenide semiconductor at multiple times. This multi-frame camera has been tested at 3.1 eV and 4.5 keV. The framing camera currently records two frames with a temporal separation between the frames of 5 ps but this separation can be varied between hundreds of femtoseconds up to nanoseconds and the number of frames can be increased by angularly multiplexing the probe beam onto the cadmium selenide semiconductor.

Method of tagging excipients with /sup 99m/Tc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bardy, A.; Beydon, J.; Gobin, R.

1977-11-08

A method of using /sup 99m/technetium for tagging excipients in medical diagnosis by scintigraphy comprises mixing, in an aqueous solution of alkali-metal pertechnetate, an excipient and a reducing agent in the form of a complex, which complex is such that the association constant of the anion with reduced techetium is less than the association constant of the excipient with reduced technetium, thereby forming a radio-pharmaceutical substance which is a complex between the excipient and /sup 99m/technetium.

TC-99 Decontaminant from heat treated gaseous diffusion membrane -Phase I, Part B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L.; Restivo, M.; Duignan, M.

2017-11-01

Uranium gaseous diffusion cascades represent a significant environmental challenge to dismantle, containerize and dispose as low-level radioactive waste. Baseline technologies rely on manual manipulations involving direct access to technetium-contaminated piping and materials. There is a potential to utilize novel decontamination technologies to remove the technetium and allow for on-site disposal of the very large uranium converters. Technetium entered these gaseous diffusion cascades as a hexafluoride complex in the same fashion as uranium. Technetium, as the isotope Tc-99, is an impurity that follows uranium in the first cycle of the Plutonium and Uranium Extraction (PUREX) process. The technetium speciation or exactmore » form in the gaseous diffusion cascades is not well defined. Several forms of Tc-99 compounds, mostly the fluorinated technetium compounds with varying degrees of volatility have been speculated by the scientific community to be present in these cascades. Therefore, there may be a possibility of using thermal or leaching desorption, which is independent of the technetium oxidation states, to perform an insitu removal of the technetium as a volatile species and trap the radionuclide on sorbent traps which could be disposed as low-level waste. Based on the positive results of the first part of this work1 the use of steam as a thermal decontamination agent was further explored with a second piece of used barrier material from a different location. This new series of tests included exposing more of the material surface to the flow of high temperature steam through the change in the reactor design, subjecting it to alternating periods of stream and vacuum, as well as determining if a lower temperature steam, i.e., 121°C (250°F) would be effective, too. Along with these methods, one other simpler method involving the leaching of the Tc-99 contaminated barrier material with a 1.0 M aqueous solution of ammonium carbonate, with and without

p-Tertbutylcalix[4]arene nanoemulsion: preparation, characterization and comparative evaluation of its decontamination efficacy against Technetium-99m, Iodine-131 and Thallium-201.

PubMed

Rana, Sudha; Sharma, Navneet; Ojha, Himanshu; Shivkumar, Hosakote Gurumalappa; Sultana, Sarwat; Sharma, Rakesh Kumar

2014-05-01

This study aimed to develop p-tertbutylcalix[4]arene o/w nanoemulsion for decontamination of radioisotopes from skin. Formulation was characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), multi-photon confocal microscopy techniques and in vitro dissolution studies. In vivo evaluation of nano-emulsion was done using nuclear medicine technique. Stability studies and dermal toxicity studies were also carried out. Comparative decontamination efficacy (DE) studies were performed on synthetic human tissue equivalent material and Sprague Dawley rat against three commonly used medical radioisotopes, i.e., Technetium-99m ((99m)Tc), Iodine-131 ((131)I) and Thallium-201 ((201)Tl). Decontamination was performed using cotton swabs soaked in nanoemulsion at different time intervals of contaminants exposure. Whole body imaging and static counts were recorded using gamma camera before and after each decontamination attempt data was analyzed using one way analysis of variance (ANOVA) and found to be statistically significant (p<0.05). DE of the nanoemulsion loaded with p-tertbutylcalix[4]arene was observed to be 88±5%, 90±3% and 89±3% for (99m)Tc, (131)I and (201)Tl respectively. Dermal toxicity studies revealed no significant differences between treated and control animals. Skin histopathology slides with and without API (Active pharmaceutical ingredients) also found to be comparable. p-Tertbutylcalix[4]arene loaded nanoemulsion shows great promise for skin decontamination against broad ranges of radiological contaminants besides being stable and safe. Copyright © 2014 Elsevier B.V. All rights reserved.

Sectorial technetium-99m-dimercaptosuccinic acid scintigraphy for monitoring the effect of extracorporeal piezoelectric lithotripsy for calyceal calculi on regional renal function.

PubMed

Al-Tawheed, A; Al-Awadi, K A; Kehinde, E O; Loutfi, I; Abdul-Haleem, H; Al-Mohannadi, S

2003-01-01

To apply a semiquantitative method for analysis of technetium-99m-dimercaptosuccinic acid ((99m)Tc-DMSA) renal scintigraphy for monitoring the effect of extracorporeal piezoelectric lithotripsy (EPL) in patients with calyceal stones on regional kidney function and to check whether EPL had caused any deleterious effect on the target calyceal renal parenchymal function. Forty patients (mean age 35 years) suffering from calyceal stones documented by abdominal plain radiography, intravenous urogram or abdominal ultrasound were studied. All patients were treated by EPL. (99m)Tc-DMSA scan was performed before and 4 weeks after EPL. Sector analysis involved calculation of the relative function of the target calyx to the function of the ipsilateral kidney and the relative function of the treated kidney to global renal function. The stone sizes were 6-11 mm in diameter and 11 were located in the upper, 13 in the middle and 16 in the lower calyx. After EPL, the overall stone clearance rate was 85% (100% for calculi in the upper and middle calyces, 62% for lower calyces). The sector analysis did not show statistically significant change of the relative regional (calyceal) or whole kidney function between the pre- and post-EPL (99m)Tc-DMSA scans. Using sector analysis, EPL appeared to be a safe modality and its usage was not associated with any untoward effect on calyceal or whole kidney function. Sector analysis of (99m)Tc-DMSA renal scan is a simple semiquantitative method for monitoring regional changes of kidney function after EPL for treatment of calyceal stone. Copyright 2003 S. Karger AG, Basel

Multicenter Trial of Sentinel Node Biopsy for Breast Cancer Using Both Technetium Sulfur Colloid and Isosulfan Blue Dye

PubMed Central

Tafra, Lorraine; Lannin, Donald R.; Swanson, Melvin S.; Van Eyk, Jason J.; Verbanac, Kathryn M.; Chua, Arlene N.; Ng, Peter C.; Edwards, Maxine S.; Halliday, Bradford E.; Henry, C. Alan; Sommers, Linda M.; Carman, Claire M.; Molin, Melinda R.; Yurko, John E.; Perry, Roger R.; Williams, Robert

2001-01-01

Objective To determine the factors associated with false-negative results on sentinel node biopsy and sentinel node localization (identification rate) in patients with breast cancer enrolled in a multicenter trial using a combination technique of isosulfan blue with technetium sulfur colloid (Tc99). Summary Background Data Sentinel node biopsy is a diagnostic test used to detect breast cancer metastases. To test the reliability of this method, a complete lymph node dissection must be performed to determine the false-negative rate. Single-institution series have reported excellent results, although one multicenter trial reported a false-negative rate as high as 29% using radioisotope alone. A multicenter trial was initiated to test combined use of Tc99 and isosulfan blue. Methods Investigators (both private-practice and academic surgeons) were recruited after attending a course on the technique of sentinel node biopsy. No investigator participated in a learning trial before entering patients. Tc99 and isosulfan blue were injected into the peritumoral region. Results Five hundred twenty-nine patients underwent 535 sentinel node biopsy procedures for an overall identification rate in finding a sentinel node of 87% and a false-negative rate of 13%. The identification rate increased and the false-negative rate decreased to 90% and 4.3%, respectively, after investigators had performed more than 30 cases. Univariate analysis of tumor showed the poorest success rate with older patients and inexperienced surgeons. Multivariate analysis identified both age and experience as independent predictors of failure. However, with older patients, inexperienced surgeons, and patients with five or more metastatic axillary nodes, the false-negative rate was consistently greater. Conclusions This multicenter trial, from both private practice and academic institutions, is an excellent indicator of the general utility of sentinel node biopsy. It establishes the factors that play an

Studies on focal alveolar bone healing with technetium (Tc)-99m labeled methylene diphosphonate and gold-collimated cadmium telluride probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuchimochi, M.; Hosain, F.; Engelke, W.

1991-01-01

The benefit of using a collimator for a miniaturized cadmium telluride probe was evaluated by monitoring the bone-healing processes for 13 weeks after the induction of small iatrogenic alveolar bone lesions in one side of the mandible in beagles. Technetium (Tc)-99m labeled methylene diphosphonate (200 to 300 MBq, 5.1 to 8.1 mCi, in a solution of 0.5 to 1 ml, intravenously) was used as a bone-seeking radiopharmaceutical. The radioactivity over the bone lesion (L) and the contralateral normal site (C) in the mandible were measured between 1.5 and 2 hours after injection of the tracer, and the activity ratio L/Cmore » served as an index of relative bone uptake. A study of six dogs revealed that the healing response to a hemispheric bone defect of 2 mm diameter in the cortical bone could not be detected by an uncollimated probe, and in a repeated study in two dogs the use of a gold collimator (5 mm in diameter, 5 mm in length) did not increase the L/C ratio significantly. A second study in six dogs with 5 mm lesions showed that although systematic trends in the time courses of the L/C ratio obtained both with and without the collimator could be demonstrated, the L/C ratio of collimated versus uncollimated measurements was significantly (p less than 0.005) increased. In three of the latter six dogs, abscesses developed after 9 weeks, leading to a second increase (p less than 0.05) of the L/C ratio with collimation compared with the noninflammation group; without collimation no significant (p greater than 0.15) difference between the two groups could be demonstrated.« less

Structural characterization of a bridged 99Tc-Sn-dimethylglyoxime complex: implications for the chemistry of 99mTc-radiopharmaceuticals prepared by the Sn (II) reduction of pertechnetate.

PubMed Central

Deutsch, E; Elder, R C; Lange, B A; Vaal, M J; Lay, D G

1976-01-01

Reduction of pertechnetate by tin(II) in the presence of dimethylglyoxime is shown, by single crystal x-ray analysis, to yield a technetium-tin-dimethylglyoxime complex in which tin and technetium are intimately connected by a triple bridging arrangement. One bridge consists of a single oxygen atom and it is hypothesized that this bridge arises from the inner sphere reduction of technetium by tin(II), the electrons being transferred through a technetium "yl" oxygen which eventually becomes the bridging atom. Two additional bridges arise from two dimethylglyoxime ligands that function as bidentate nitrogen donors towards Tc and monodentate oxygen donors towards Sn. The tin atom can thus be viewed as providing a three-pronged "cap" on one end of the Tc-dimethylglyoxime complex. The additional coordination sites around Tc are occupied by the two nitrogens of a third dimethylglyoxime ligand, making the Tc seven-coordinate. The additional coordination sites around Sn are occupied by three chloride anions, giving the Sn a fac octahedral coordination environment. From indirect evidence the oxidation states of tin and technetium are tentatively assigned to be IV and V, respectively. Since most 99mTc-radiopharmaceuticals are synthesized by the tin(II) reduction of pertechnetate, it is likely that the Sn-O-Tc linkage described in this work is an important feature of the chemistry of these species. This linkage also provides a ready rationale for the close association of tin and technetium observed in many 99mTc-radiopharmaceuticals. PMID:1069984

Radioactive excretion in human milk following administration of /sup 99m/Tc macroaggregated albumin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pittard, W.B.; Merkatz, R.; Fletcher, B.D.

Albumin-tagged sodium pertechnetate (technetium) is routinely used in nuclear medicine for scanning procedures of the lung. The rate of excretion of this radionuclide into breast milk and the resultant potential radiation hazard to the nursing infant have received little attention. Therefore the milk from a nursing mother who required a lung scan because of suspected pulmonary emboli using an intravenous injection of 4 mCi of /sup 99m/Tc macroaggregated human serum albumin was monitored. Albumin tagging severely limited the entrance of technetium into her milk and the radioactivity of the milk returned to base line by 24 hours. A total ofmore » 2.02 muCi of technetium was measured in the 24-hour milk collection after technetium injection and 94% of this amount was excreted by 15.5 hours. This amount of technetium administered orally to a newborn would deliver a total body radiation dose of .3 mrad. Therefore, an infant would receive trivial doses of radiation if breast-feeding were resumed 15.5 hours after administration of the radionuclide to the mother and nursing can clearly be resumed safely 24 hours after injection.« less

Selenium speciation in Lower Cambrian Se-enriched strata in South China and its geological implications

NASA Astrophysics Data System (ADS)

Fan, Haifeng; Wen, Hanjie; Hu, Ruizhong; Zhao, Hui

2011-12-01

To understand the impact of Selenium (Se) into the biogeochemical cycle and implications for palaeo-redox environment, a sequential extraction method was utilized for samples including black shales, cherts, a Ni-Mo-Se sulfide layer, K-bentonite and phosphorite from Lower Cambrian Se-enriched strata in southern China. Seven species (water-soluble, phosphate exchangeable, base-soluble, acetic acid-soluble, sulfide/selenide associated, residual Se) and different oxidation states (selenate Se(VI), selenite Se(IV), organic Se, Se (0) and mineral Se(-II)) were determinated in this study. We found that the Ni-Mo-Se sulfide layer contained a significantly greater amount of Se(-II) associated with sulfides/selenides than those in host black shales and cherts. Furthermore, a positive correlation between the degree of sulfidation of iron (DOS) and the percentage of the sulfide/selenide-associated Se(-II) was observed for samples, which suggests the proportion of sulfide/selenide-associated Se(-II) could serve as a proxy for palaeo-redox conditions. In addition, the higher percentage of Se(IV) in K-bentonite and phosphorite was found and possibly attributed to the adsorption of Se by clay minerals, iron hydroxide surfaces and organic particles. Based on the negative correlations between the percentage of Se(IV) and that of Se(-II) in samples, we propose that the K-bentonite has been altered under the acid oxic conditions, and the most of black shale (and cherts) and the Ni-Mo-Se sulfide layer formed under the anoxic and euxinic environments, respectively. Concerning Se accumulation in the Ni-Mo-Se sulfide layer, the major mechanism can be described by (1) biotic and abiotic adsorption and further dissimilatory reduction from oxidized Se(VI) and Se(IV) to Se(-II), through elemental Se, (2) contribution of hydrothermal fluid with mineral Se(-II).

Nuclear waste solutions

DOEpatents

Walker, Darrel D.; Ebra, Martha A.

1987-01-01

High efficiency removal of technetium values from a nuclear waste stream is achieved by addition to the waste stream of a precipitant contributing tetraphenylphosphonium cation, such that a substantial portion of the technetium values are precipitated as an insoluble pertechnetate salt.

Technetium Incorporation in Glass for the Hanford Tank Waste Treatment and Immobilization Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruger, Albert A.; Kim, Dong Sang

2015-01-14

A priority of the United States Department of Energy (U.S. DOE) is to dispose of nuclear wastes accumulated in 177 underground tanks at the Hanford Nuclear Reservation in eastern Washington State. These nuclear wastes date from the Manhattan Project of World War II and from plutonium production during the Cold War. The DOE plans to separate high-level radioactive wastes from low activity wastes and to treat each of the waste streams by vitrification (immobilization of the nuclides in glass) for disposal. The immobilized low-activity waste will be disposed of here at Hanford and the immobilized high-level waste at the nationalmore » geologic repository. Included in the inventory of highly radioactive wastes is large volumes of 99Tc (~9 × 10E2 TBq or ~2.5 × 104 Ci or ~1500 kg). A problem facing safe disposal of Tc-bearing wastes is the processing of waste feed into in a chemically durable waste form. Technetium incorporates poorly into silicate glass in traditional glass melting. It readily evaporates during melting of glass feeds and out of the molten glass, leading to a spectrum of high-to-low retention (ca. 20 to 80%) in the cooled glass product. DOE-ORP currently has a program at Pacific Northwest National Laboratory (PNNL), in the Department of Materials Science and Engineering at Rutgers University and in the School of Mechanical and Materials Engineering at Washington State University that seeks to understand aspects of Tc retention by means of studying Tc partitioning, molten salt formation, volatilization pathways, and cold cap chemistry. Another problem involves the stability of Tc in glass in both the national geologic repository and on-site disposal after it has been immobilized. The major environmental concern with 99Tc is its high mobility in addition to a long half-life (2.1×105 yrs). The pertechnetate ion (TcO4-) is highly soluble in water and does not adsorb well onto the surface of minerals and so migrates nearly at the same velocity as

Screening for Hepatopulmonary Syndrome in Cirrhotic Patients Using Technetium 99m-macroaggregated Albumin Perfusion Lung Scan (Tc-MAA): Diagnostic Approach and Clinical Correlations.

PubMed

Fragaki, Maria; Sifaki-Pistolla, Dimitra; Samonakis, Dimitrios N; Koulentaki, Mairi; Koukouraki, Sofia; Stathaki, Maria; Kouroumalis, Elias

2017-09-28

The aims of this study were to prospectively screen cirrhotic patients with arterial blood gas test and albumin perfusion scan, identify those fulfilling the classic hepatopulmonary syndrome (HPS) criteria, correlate with clinical parameters, and evaluate the survival of patients with HPS compared with those without HPS in a genetically homogenous Cretan cirrhotic population. Data on consecutive 102 patients within 1 year were collected and analyzed. All patients underwent a technetium 99m-macroaggregated albumin perfusion lung scan (Tc-MAA). Diagnosis of HPS was based on the presence of the quantitative index Tc-MAA≥6% and a [P(A-a)O2]≥15 mm Hg (≥20 mm Hg for patients over >64 y). In 94/102 patients, complete scintigraphic data were available. In total, 24 (26%) patients fulfilled the diagnostic criteria of HPS; 95.8% of them had mild-to-moderate HPS. In 8 patients the Tc-MAA scintigraphy could not be interpreted. There was no difference in HPS between decompensated (24.6%) and compensated cirrhosis (27.3%). In the multivariate analysis only the quantitative index was significant for the diagnosis of HPS (P=0.001, odds ratio; 95% confidence interval, 7.05; 2.27-21.87). Kaplan- Meier survival curves indicated a similar overall prognosis for patients diagnosed with HPS (P=0.105). HPS is a frequent complication of cirrhosis. Mild-to-moderate HPS has no significant effect on survival of cirrhotic patients. The quantitative Tc-MAA test is a reliable tool for diagnosis.

Green biosynthesis of biocompatible CdSe quantum dots in living Escherichia coli cells

NASA Astrophysics Data System (ADS)

Yan, Zhengyu; Qian, Jing; Gu, Yueqing; Su, Yilong; Ai, Xiaoxia; Wu, Shengmei

2014-03-01

A green and efficient biosynthesis method to prepare fluorescence-tunable biocompatible cadmium selenide quantum dots using Escherichia coli cells as biological matrix was proposed. Decisive factors in biosynthesis of cadmium selenide quantum dots in a designed route in Escherichia coli cells were elaborately investigated, including the influence of the biological matrix growth stage, the working concentration of inorganic reactants, and the co-incubation duration of inorganic metals to biomatrix. Ultraviolet-visible, photoluminescence, and inverted fluorescence microscope analysis confirmed the unique optical properties of the biosynthesized cadmium selenide quantum dots. The size distribution of the nanocrystals extracted from cells and the location of nanocrystals foci in vivo were also detected seriously by transmission electron microscopy. A surface protein capping layer outside the nanocrystals was confirmed by Fourier transform infrared spectroscopy measurements, which were supposed to contribute to reducing cytotoxicity and maintain a high viability of cells when incubating with quantum dots at concentrations as high as 2 μM. Cell morphology observation indicated an effective labeling of living cells by the biosynthesized quantum dots after a 48 h co-incubation. The present work demonstrated an economical and environmentally friendly approach to fabricating highly fluorescent quantum dots which were expected to be an excellent fluorescent dye for broad bio-imaging and labeling.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl; Rodríguez, C.A.; Porcile-Saavedra, P.F.

Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of themore » crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.« less

Evaluation of the biliary and brain distribution of technetium Tc 99m sestamibi in healthy dogs with the ABCB1 wildtype genotype before and after treatment with spinosad.

PubMed

MacKay, Christopher S; Mattoon, John S; Roberts, Gregory D; Tucker, Russell L; Morimoto, Trevor R; Mealey, Katrina L

2012-06-01

To determine whether the reported drug-drug interaction between the flea medication spinosad and ivermectin is attributable to inhibition of P-glycoprotein by spinosad. 6 healthy adult dogs with the ABCB1 wildtype genotype. The study was conducted as a prospective, masked, randomized crossover design. Six dogs were allocated to 2 groups; each dog served as its own control animal. Dogs in one of the groups received spinosad at the manufacturer's recommended dose; the other group received no treatment. Forty-eight hours later, scintigraphic imaging of the head and abdomen were performed with the radiolabeled P-glycoprotein substrate methoxy-isobutyl-isonitrile (sestamibi) in both groups of dogs. After a washout period of 60 days, the dogs in each group received the alternate treatment, and scintigraphic imaging again was performed 48 hours later. Gallbladder-to-liver and brain-to-neck musculature ratios of technetium Tc 99m sestamibi were calculated for each dog and compared between treatments. No significant differences in gallbladder-to-liver or brain-to-neck musculature ratios were found between treatments. Results provided evidence that spinosad did not inhibit P-glycoprotein function 48 hours after spinosad was administered at the manufacturer's recommended dose. Further investigations will be necessary to elucidate the mechanism of the reported toxic interaction between spinosad and ivermectin.

Materials for Tc Capture to Increase Tc Retention in Glass Waste Form

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luksic, Steven A.; Hrma, Pavel R.; Kruger, Albert A.

99Technetium is a long-lived fission product found in the tank waste at the Hanford site in Washington State. In its heptavalent species, it is volatile at the temperatures used in Hanford Tank Waste Treatment and Immobilization Plant vitrification melters, and thus is challenging to incorporate into waste glass. In order to decrease volatility and thereby increase retention, technetium can be converted into more thermally stable species. Several mineral phases, such as spinel, are able to incorporate tetravalent technetium in a chemically durable and thermally stable lattice, and these hosts may promote the decreased volatility that is desired. In order tomore » be usefully implemented, there must be a synthetic rout to these phases that is compatible with both technetium chemistry and current Hanford Tank Waste Treatment and Immobilization Plant design. Synthetic routes for spinel and other potential host phases are examined.« less

Postoperative myocardial infarction documented by technetium pyrophosphate scan using single-photon emission computed tomography: Significance of intraoperative myocardial ischemia and hemodynamic control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, D.C.; Chung, F.; Burns, R.J.

The aim of this prospective study was to document postoperative myocardial infarction (PMI) by technetium pyrophosphate scan using single-photon emission computed tomography (TcPPi-SPECT) in 28 patients undergoing elective coronary bypass grafting (CABG). The relationships of intraoperative electrocardiographic myocardial ischemia, hemodynamic responses, and pharmacological requirements to this incidence of PMI were correlated. Radionuclide cardioangiography and TcPPi-SPECT were performed 24 h preoperatively and 48 h postoperatively. A standard high-dose fentanyl anesthetic protocol was used. Twenty-five percent of elective CABG patients were complicated with PMI, as documented by TcPPi-SPECT with an infarcted mass of 38.0 +/- 5.5 g. No significant difference in demographic,more » preoperative right and left ventricular function, number of coronary vessels grafted, or aortic cross-clamp time was observed between the PMI and non-PMI groups. The distribution of patients using preoperative beta-adrenergic blocking drugs or calcium channel blocking drugs was found to have no correlation with the outcome of PMI. As well, no significant differences in hemodynamic changes or pharmacological requirements were observed in the PMI and non-PMI groups during prebypass or postbypass periods, indicating careful intraoperative control of hemodynamic indices did not prevent the outcome of PMI in these patients. However, the incidence of prebypass ischemia was 39.3% and significantly correlated with the outcome of positive TcPPi-SPECT, denoting a 3.9-fold increased risk of developing PMI. Prebypass ischemic changes in leads II and V5 were shown to correlate with increased CPK-MB release (P less than 0.05) and tends to occur more frequently with lateral myocardial infarction.« less

[Course of ejection fraction, regurgitation fraction and ventricular volumes during exertion in chronic aortic insufficiency. Study using technetium 99m gamma-cineangiography].

PubMed

Bassand, J P; Faivre, R; Berthout, P; Cardot, J C; Verdenet, J; Bidet, R; Maurat, J P

1985-06-01

Previous studies have shown that variations of the ejection fraction (EF) during exercise were representative of the contractile state of the left ventricle: an increased EF on effort is considered to be physiological, whilst a decrease would indicate latent LV dysfunction unmasked during exercise. This hypothesis was tested by performing Technetium 99 gamma cineangiography at equilibrium under basal conditions and at maximal effort in 8 healthy subjects and 44 patients with pure, severe aortic regurgitation to measure the ejection and regurgitant fractions and the variations in end systolic and end diastolic LV volume. In the control group the EF increased and end systolic volume decreased significantly on effort whilst the regurgitant fraction and end diastolic volume were unchanged. In the 44 patients with aortic regurgitation no significant variations in EF, end systolic and end diastolic volumes were observed because the individual values were very dispersed. Variations of the EF and end systolic volume were inversely correlated. The regurgitant fraction decreased significantly on effort. Based on the variations of the EF and end systolic volume three different types of response to effort could be identified: in 7 patients, the EF increased on effort and end systolic volume decreased without any significant variation in the end diastolic volume, as in the group of normal control subjects; in 22 patients, a reduction in EF was observed on effort, associated with an increased end systolic volume. These changes indicated latent IV dysfunction inapparent at rest and unmasked by exercise; in a third group of 15 patients, the EF decreased on effort despite a physiological decrease in end systolic volume due to a greater decrease in end diastolic volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Human Fibronectin Extra-Domain B (EDB)-Specific Aptide (APTEDB) Radiolabelling with Technetium-99m as a Potent Targeted Tumour-Imaging Agent.

PubMed

Mohammadgholi, Mohsen; Sadeghzadeh, Nourollah; Erfani, Mostafa; Abediankenari, Saeid; Abedi, Seyed Mohammad; Emrarian, Iman; Jafari, Narjes; Behzadi, Ramezan

2018-01-01

Human fibronectin extra-domain B (EDB) is particularly expressed during angiogenesis progression. It is, thus, a promising marker of tumour growth. Aptides are a novel class of peptides with high-affinity binding to specific protein targets. APTEDB is an antagonist-like ligand that especially interacts with human fibronectin EDB. This study was the first attempt in which the hydrazinonicotinamide (HYNIC)-conjugated APTEDB was labelled with technetium-99m (99mTc) as an appropriate radiotracer and tricine/EDDA exchange labeling. Radiochemical purity, normal saline, and serum stability were evaluated by HPLC and radio-isotope TLC scanner. Other examinations, such as protein-binding calculation, dissociation radioligand binding assay, and partition coefficient constant determination, were also carried out. The cellular-specific binding of 99mTc- HYNIC-conjugated APTEDB was assessed in two EDB-positive (U87MG) and EDB-negative (U373MG) cell lines. Bio-distribution was investigated in normal mice as well as in U87MG and U373MG tumour-bearing mice. Eventually, the radiolabelled APTEDB was used for tumour imaging using planar SPECT. Radiolabelling was achieved with high purity (up to 97%) and accompanied by high solution (over 90% after overnight) and serum (80% after 2 hours) stability. The obtained cellular-specific binding ratio was greater than nine-fold. In-vivo experiments showed rapid blood clearance with mainly renal excretion and tumour uptake specificity (0.48±0.03% ID/g after 1h). The results of the imaging also confirmed considerable tumour uptake for EDB-positive cell line compared with the EDB-negative one. Aptides are considered to be a potent candidate for biopharmaceutical applications. They can be modified with imaging or therapeutic agents. This report shows the capability of 99mTc-HYNIC-APTEDB for human EDB-expressing tumours detection. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of metabolic alterations on the accumulation of technetium-99m-labeled d, l-HMPAO in slices of rat cerebral cortex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, C.S.; Tow, D.E.; Yu, C.C.

1994-03-01

It is widely recognized that the distribution of technetium-99m-labeled d,l-hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) in the brain is determined by the regional blood flow. However, other factors may affect this process including the metabolism of the brain tissue. To examine this possibility we studied the effects of metabolic alterations on {sup 99m}Tc-HMPAO uptake in rat brain cortex slices, with concurrent measurement of oxygen consumption (QO{sub 2}). {sup 99m}Tc-HMPAO uptake was determined by incubating slices of rat cerebral cortex at 37{degrees}C in Krebs-Ringer phosphate glucose medium containing {sup 99m}Tc-HMPAO with and without test substances. Differential gradients for {sup 99m}Tc activity betweenmore » the tissue and the suspending medium (T/M ratio) were derived from the equation T/M[{sup 99m}Tc] = counts per gram of tissue/counts per milliliter of medium. The QO{sub 2} of the brain slices was measured using a biological oxygen monitor equipped with a polarographic oxygen probe. Inhibitors affecting oxidative phosphorylation caused parallel suppression of the T/M ratio and QO{sub 2}. Agents that uncouple oxidation from phosphorylation increased the QO{sub 2} and decreased the T/M ratio. Incubation of slices at 22{degrees}C depressed the T/M ratio and QO{sub 2}. The presence of inhibitors of oxidative phosphorylation in the incubation medium increased the release of {sup 99m}Tc activity from slices that had been prelabeled with {sup 99m}Tc-HMPAO. These findings suggest that the altered metabolic status of the brain tissue modulates the kinetics and net accumulation of {sup 99m}Tc-HMPAO at the cellular level by either depressing uptake, increasing back-diffusion, or both. 33 refs., 4 figs., 3 tabs.« less

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2011 CFR

2011-01-01

... .1 Technetium-99m 100 1. Technetium-99 1 .01 Tellurium-125m 1 .01 Tellurium-127m 1 .01 Tellurium-127 10 .1 Tellurium-129m 1 .01 Tellurium-129 100 1 Tellurium-131m 10 .1 Tellurium-132 1 .01 Terbium-160 1...

10 CFR 33.100 - Schedule A.

Code of Federal Regulations, 2010 CFR

2010-01-01

... .1 Technetium-99m 100 1. Technetium-99 1 .01 Tellurium-125m 1 .01 Tellurium-127m 1 .01 Tellurium-127 10 .1 Tellurium-129m 1 .01 Tellurium-129 100 1 Tellurium-131m 10 .1 Tellurium-132 1 .01 Terbium-160 1...

Dissolution of spent nuclear fuel in carbonate-peroxide solution

NASA Astrophysics Data System (ADS)

Soderquist, Chuck; Hanson, Brady

2010-01-01

This study shows that spent UO2 fuel can be completely dissolved in a room temperature carbonate-peroxide solution apparently without attacking the metallic Mo-Tc-Ru-Rh-Pd fission product phase. In parallel tests, identical samples of spent nuclear fuel were dissolved in nitric acid and in an ammonium carbonate, hydrogen peroxide solution. The resulting solutions were analyzed for strontium-90, technetium-99, cesium-137, europium-154, plutonium, and americium-241. The results were identical for all analytes except technetium, where the carbonate-peroxide dissolution had only about 25% of the technetium that the nitric acid dissolution had.

Radioguided localisation of impalpable breast lesions using 99m-Technetium macroaggregated albumin: Lessons learnt during introduction of a new technique to guide preoperative localisation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landman, Joanne; Kulawansa, Sagarika; McCarthy, Michael

2015-03-15

Preoperative wire-guided localisation (WGL) of impalpable breast lesions is widely used but can be technically difficult. Risks include wire migration, inaccurate placement, and inadequate surgical margins. Research shows that radioguided occult lesion localisation (ROLL) is quicker, easier, and can improve surgical and cosmetic outcomes. An audited introduction of ROLL was conducted to validate the technique as a feasible alternative to WGL. Fifty patients with single impalpable lesions and biopsy proven malignancy or indeterminate histology underwent WGL followed by intralesional radiopharmaceutical injection of 99m-Technetium macroaggregated albumin. Postprocedural mammography was performed to demonstrate wire position, and scintigraphy to evaluate radiopharmaceutical migration. Lymphoscintigraphymore » and intraoperative sentinel node biopsy were performed if indicated, followed by lesion localisation and excision using a gamma probe. Specimen imaging was performed, with immediate reexcision for visibly inadequate margins. Accurate localisation was achieved in 86% of patients with ROLL compared to 72% with WGL. All lesions were successfully removed, with clear margins in 71.8% of malignant lesions. Reexcision and intraoperative sentinel node localisation rates were equivalent to preaudit figures for WGL. ROLL was easy to perform and problems were infrequent. Inaccurate radiopharmaceutical placement necessitating WGL occurred in four patients. Minor radiopharmaceutical migration was common, but precluded using ROLL in only two cases. ROLL is effective, simple, inexpensive, and easily learnt; however, preoperative confirmation of correct radiopharmaceutical placement using mammography and the gamma probe is important to help ensure successful lesion removal. Insertion of a backup hookwire is recommended during the initial introduction of ROLL.« less

PbS-PbSe IR detector arrays

NASA Technical Reports Server (NTRS)

Barrett, John R. (Inventor)

1986-01-01

A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chipping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

Method of fabricating a PbS-PbSe IR detector array

NASA Technical Reports Server (NTRS)

Barrett, John R. (Inventor)

1987-01-01

A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chiping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

Thermoelectric Properties of Selenides Spinels

NASA Technical Reports Server (NTRS)

Snyder, G.; Caillat, T.; Fleurial, J-P.

2000-01-01

Many compounds with the spinel structure type have been analyzed for their thermoelectric properties. Published data was used to augment experimental results presented here to select promising thermoelectric spinels.

Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsey, William G.; Esparza, Brian P.

2013-07-01

Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls formore » the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)« less

Technetium-99m-Labeled Sulfadiazine: a Targeting Radiopharmaceutical for Scintigraphic Imaging of Infectious Foci Due To Escherichia coli in Mouse and Rabbit Models.

PubMed

Ahmed, Muhammad Tauqeer; Naqvi, Syed Ali Raza; Rasheed, Rashid; Zahoor, Ameer Fawad; Usman, Muhammad; Hussain, Zaib

2017-09-01

Bacterial infection is one of the vital reasons of morbidity and mortality, especially in developing countries. It appears silently without bothering the geological borders and imposes a grave threat to humanity. Nuclear medicine technique has an important role in helping early diagnosis of deep-seated infections. The aim of this study was to develop a new radiopharmaceutical 99m Tc-labeling sulfadiazine as an infection imaging agent. Radiolabeling of sulfadiazine with technetium-99m ( 99m Tc) was carried out using stannous tartrate as a reducing agent in the presence of gentistic acid at pH = 5. The quality control tests revealed ~98% labeling efficiency. Paper chromatographic (PC) and instant thin-layer chromatographic (ITLC) techniques were used to analyze radiochemical yield. Biodistribution and infection specificity of the radiotracer were performed with Escherichia coli (E. coli) infection-induced rats. Scintigraphy and glomerular filtration rate (GFR) study was performed in E. coli-infected rabbits. Scintigraphy indicated E. coli infection targeting potential of 99m Tc-SDZ, while biodistribution study showed minimal uptake of 99m Tc-SDZ in non-targeted tissues. The uptake in the kidneys was found 2.56 ± 0.06, 2.09 ± 0.10, and 1.68 ± 0.09% at 30 min, 1 h, and 4 h, respectively. The infected muscle (target) to non-infected muscle (non-target) ratio (T/NT) was found 4.49 ± 0.04, 6.78 ± 0.07, and 5.59 ± 0.08 at 30 min, 1 h, and 4 h, respectively.

Breaking America’s Dependence on Foreign…Molybdenum

PubMed Central

Einstein, Andrew J.

2009-01-01

Brief Unstructured Abstract Approximately 9 million nuclear cardiology studies performed each year in the United States employ technetium-99m, which is produced from the decay of molybdenum-99. The fragility of the worldwide technetium-99m supply chain has been underscored by current shortages caused by an unplanned shutdown of Europe’s largest reactor. The majority of the United States’ supply derives from a reactor in Canada nearing the end of its lifespan, whose planned replacements have been recently cancelled. In this article, the clinical importance of technetium-99m and our tenuous dependence on foreign supply of Molybdenum is addressed. PMID:19356583

Differences in the intracellular processing of the radiolabel following the uptake of iodine-125- and technetium-99m-neogalactosyl albumin by the isolated perfused rat liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gore, S.; Morris, A.I.; Gilmore, I.T.

1991-03-01

Neogalactosyl albumin (NGA) is a synthetic ligand to the asialoglycoprotein receptor (hepatic binding protein), which has been proposed as a useful receptor binding radiopharmaceutical for the noninvasive assessment of liver function. We have compared the uptake and intracellular processing of iodine-125- (125I) and technetium-99m- ({sup 99m}Tc) NGA following its administration as a 1-min pulse (147 pmol) to the isolated perfused rat liver. Approximately 40% of a pulse of either {sup 125}I- or {sup 99m}Tc-NGA were taken up first pass by the liver. Of the {sup 125}I taken up by the liver, 82% was released after 15-20 min at the sinusoidalmore » pole of the hepatocyte, predominantly as small molecular weight metabolites. A further 8% of the {sup 125}I-associated radioactivity was secreted as intact NGA into bile by the non-lysosomal (direct) pathway while 6% remained in the liver 1 hr after the pulse. In contrast, of the {sup 99m}Tc taken up by the liver, only 4% reappeared in the perfusate while 40% was secreted into bile by the lysosomal (indirect) pathway and 55% remained in the liver 1 hr after the pulse. Since labeled metabolites of {sup 99m}Tc-NGA do not appear in plasma, this permits kinetic modeling with {sup 99m}Tc-NGA without correction for labeled metabolites. Thus, {sup 99m}Tc-NGA is an excellent candidate as a receptor-binding radiopharmaceutical.« less

High-temperature superconductivity: A conventional conundrum

DOE PAGES

Božović, Ivan

2016-01-07

High-temperature superconductivity in ultrathin films of iron selenide deposited on strontium titanate has been attributed to various exotic mechanisms, and new experiments indicate that it may be conventional, with broader implications.

Technetium uptake predicts remission and relapse in Grave's disease patients on antithyroid drugs for at least 1 year in South Indian subjects

PubMed Central

Singhal, Neha; Praveen, V. P.; Bhavani, Nisha; Menon, Arun S.; Menon, Usha; Abraham, Nithya; Kumar, Harish; JayKumar, R. V.; Nair, Vasantha; Sundaram, Shanmugha; Sundaram, Padma

2016-01-01

Context: Most of the information on remission related factors in Grave's disease are derived from Western literature. It is likely that there may be additional prognostic factors and differences in the postdrug treatment course of Grave's disease in India. Aim: To study factors which predict remission/relapse in Grave's disease patients from South India. Also to establish if technetium (Tc) uptake has a role in predicting remission. Subjects and Methods: Records of 174 patients with clinical, biochemical, and scintigraphic criteria consistent with Grave's disease, seen in our Institution between January 2006 and 2014 were analyzed. Patient factors, drug-related factors, Tc-99m uptake and other clinical factors were compared between the remission and nonremission groups. Statistical Analysis Used: Mann–Whitney U-test and Chi-square tests were used when appropriate to compare the groups. Results: Fifty-seven (32.7%) patients attained remission after at least 1 year of thionamide therapy. Of these, 11 (19.2%) patients relapsed within 1 year. Age, gender, goiter, and presence of extrathyroidal manifestations were not associated with remission. Higher values of Tc uptake were positively associated with remission (P- 0.02). Time to achievement of normal thyroid function and composite dose: Time scores were significantly associated with remission (P - 0.05 and P - 0.01, respectively). Patients with lower FT4 at presentation had a higher chance of remission (P - 0.01). The relapse rates were lower than previously reported in the literature. A higher Tc uptake was found to be significantly associated with relapse also (P - 0.009). Conclusion: The prognostic factors associated with remission in Graves's disease in this South Indian study are not the same as that reported in Western literature. Tc scintigraphy may have an additional role in identifying people who are likely to undergo remission and thus predict the outcome of Grave's disease. PMID:27042408

Technetium uptake predicts remission and relapse in Grave's disease patients on antithyroid drugs for at least 1 year in South Indian subjects.

PubMed

Singhal, Neha; Praveen, V P; Bhavani, Nisha; Menon, Arun S; Menon, Usha; Abraham, Nithya; Kumar, Harish; JayKumar, R V; Nair, Vasantha; Sundaram, Shanmugha; Sundaram, Padma

2016-01-01

Most of the information on remission related factors in Grave's disease are derived from Western literature. It is likely that there may be additional prognostic factors and differences in the postdrug treatment course of Grave's disease in India. To study factors which predict remission/relapse in Grave's disease patients from South India. Also to establish if technetium (Tc) uptake has a role in predicting remission. Records of 174 patients with clinical, biochemical, and scintigraphic criteria consistent with Grave's disease, seen in our Institution between January 2006 and 2014 were analyzed. Patient factors, drug-related factors, Tc-99m uptake and other clinical factors were compared between the remission and nonremission groups. Mann-Whitney U-test and Chi-square tests were used when appropriate to compare the groups. Fifty-seven (32.7%) patients attained remission after at least 1 year of thionamide therapy. Of these, 11 (19.2%) patients relapsed within 1 year. Age, gender, goiter, and presence of extrathyroidal manifestations were not associated with remission. Higher values of Tc uptake were positively associated with remission (P- 0.02). Time to achievement of normal thyroid function and composite dose: Time scores were significantly associated with remission (P - 0.05 and P - 0.01, respectively). Patients with lower FT4 at presentation had a higher chance of remission (P - 0.01). The relapse rates were lower than previously reported in the literature. A higher Tc uptake was found to be significantly associated with relapse also (P - 0.009). The prognostic factors associated with remission in Graves's disease in this South Indian study are not the same as that reported in Western literature. Tc scintigraphy may have an additional role in identifying people who are likely to undergo remission and thus predict the outcome of Grave's disease.

RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

AA KRUGER; A GOEL; CP RODRIGUEZ

2012-08-13

The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant becausemore » of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.« less

Technetium tc 99m-labeled red blood cells in the preoperative diagnosis of cavernous hemangioma and other vascular orbital tumors.

PubMed

Polito, Ennio; Burroni, Luca; Pichierri, Patrizia; Loffredo, Antonio; Vattimo, Angelo G

2005-12-01

To evaluate technetium Tc 99m (99mTc) red blood cell scintigraphy as a diagnostic tool for orbital cavernous hemangioma and to differentiate between orbital masses on the basis of their vascularization. We performed 99mTc red blood cell scintigraphy on 23 patients (8 female and 15 male; mean age, 47 years) affected by an orbital mass previously revealed with computed tomography (CT) and magnetic resonance imaging (MRI) and suggesting cavernous hemangioma. In our diagnosis, we considered the orbital increase delayed uptake with the typical scintigraphic pattern known as perfusion blood pool mismatch. The patients underwent biopsy or surgical treatment with transconjunctival cryosurgical extraction when possible. Single-photon emission tomography (SPET) showed intense focal uptake in the orbit corresponding to radiologic findings in 11 patients who underwent surgical treatment and pathologic evaluation (9 cavernous hemangiomas, 1 hemangiopericytoma, and 1 lymphangioma). Clinical or histologic examination of the remaining 22 patients revealed the presence of 5 lymphoid pseudotumors, 2 lymphomas, 2 pleomorphic adenomas of the lacrimal gland, 1 astrocytoma, 1 ophthalmic vein thrombosis, and 1 orbital varix. The confirmation of the preoperative diagnosis by 99mTc red blood cell scintigraphy shows that this technique is a reliable tool for differentiating cavernous hemangiomas from other orbital masses (sensitivity, 100%; specificity, 86%) when ultrasound, CT, and MRI are not diagnostic. Unfortunately, 99mTc red blood cell scintigraphy results were positive in 1 patient with hemangiopericytoma and 1 patient with lymphangioma, which showed increased uptake in the lesion on SPET images because of the vascular nature of these tumors. Therefore, in these cases, the SPET images have to be integrated with data regarding clinical preoperative evaluation and CT scans or MRI studies. On the basis of our study, a complete diagnostic picture, CT scans or MRI studies, and

Use of carbonated water in reduction of adjacent gastric activity in 456 consecutive technetium-99m myocardial perfusion imaging studies.

PubMed

Thomas, Dustin M; Lee, Joshua S; Charmforoush, Anthony; Rubal, Bernard J; Rosenblatt, Stephen A; Butler, Joshua T; Clemenshaw, Michael; Cheezum, Michael K; Slim, Ahmad M

2015-12-01

Small, observational trials have suggested a reduction in adjacent gastric activity with ingestion of soda water in myocardial perfusion imaging (MPI). We report our findings prior to and after implementation of soda water in 467 consecutive MPI studies. Consecutive MPI studies performed at a high-volume facility referred for vasodilator (VD) or exercise treadmill testing (ETT) were retrospectively reviewed before and after implementation of the soda water protocol. Patients undergoing the soda water protocol received 100 ml of soda water administered 30 min prior to image acquisition and after stress. Studies were performed using a same day rest/stress protocol. Incidence of adjacent gastric activity, diaphragmatic attenuation, stress and rest perfusion defects, and major adverse cardiovascular events (MACE) outcomes defined as death, myocardial infarction, stroke, reevaluation for chest pain, and late revascularization (>90 days from MPI) were abstracted using International Classification of Diseases, Ninth Revision (ICD-9) search. Two hundred and eighteen studies were performed prior to implementation of the soda water protocol and 249 studies were performed with the use of soda water. Baseline demographic data were equal between the groups with the exception of more patients undergoing VD stress receiving soda water (p < 0.001). Soda water was not associated with a decreased incidence of adjacent gastric activity with stress (54.7% versus 61.9% with no soda water, p = 0.129) or rest (68.6% versus 69.5% with no soda water, p = 0.919) imaging. Less adjacent gastric activity was observed with patients undergoing ETT who received soda water (42.5% versus 56.9% with no soda water, p = 0.031), but no difference was observed between the groups with VD stress (69.0% versus 68.1% with no soda water, p = 1.000). The use of soda water prior to technetium-99m MPI was associated with lower rates of adjacent gastric activity only in patients undergoing ETT stress but not

99mTechnetium-based Prostate-specific Membrane Antigen-radioguided Surgery in Recurrent Prostate Cancer.

PubMed

Maurer, Tobias; Robu, Stephanie; Schottelius, Margret; Schwamborn, Kristina; Rauscher, Isabel; van den Berg, Nynke S; van Leeuwen, Fijs W B; Haller, Bernhard; Horn, Thomas; Heck, Matthias M; Gschwend, Jürgen E; Schwaiger, Markus; Wester, Hans-Jürgen; Eiber, Matthias

2018-04-03

Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) can visualize metastatic lesions in recurrent prostate cancer (PC). However, reliable identification of small and/or atypically localized lesions during salvage surgery procedures is challenging. To describe the technique, feasibility, and short-term outcomes of 99m Technetium ( 99m Tc)-based PSMA-radioguided surgery ( 99m Tc-PSMA-RGS) for removal of recurrent PC lesions. Thirty-one consecutive patients with evidence of recurrent PC on 68 Ga-PSMA N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-N,N'-diacetic acid ( 68 Ga-PSMA-11) PET after radical prostatectomy undergoing 99m Tc-PSMA-RGS were retrospectively analyzed. Salvage surgery with intraoperative radioguidance using a gamma probe was performed after intravenous application of 99m Tc-PSMA investigation and surgery (mean activity 571 MBq, mean time to surgery 19.7h). Radioactive rating (positive vs negative) of resected tissue was compared with the findings of postoperative histopathological analysis. Best prostate-specific antigen (PSA) response without additional treatment was determined after 8-16 wk postoperatively. Biochemical recurrence- and treatment-free survival was evaluated. In total, 132 tissue specimens were removed, of which 58 showed metastatic involvement on histological analysis. On a specimen basis, radioactive rating yielded a sensitivity of 83.6% (confidence interval [CI]: 70.9-91.5%), a specificity of 100%, and an accuracy of 93.0% (CI: 85.5-96.7%). With 99m Tc-PSMA-RGS, all lesions visualized on preoperative 68 Ga-PSMA-11 PET could be removed. Moreover, 99m Tc-PSMA-RGS detected additional metastases as small as 3mm in two patients. Thirteen patients suffered from complications related to surgery (Clavien-Dindo grade 1: 12 patients; grade 3a: one patient). A PSA reduction below 0.2 ng/ml was observed in 20 patients. Thirteen patients remained biochemical recurrence free after a median follow

Fast Photo-detection in Phototransistors based on Group III-VI Layered Materials.

NASA Astrophysics Data System (ADS)

Patil, Prasanna; Ghosh, Sujoy; Wasala, Milinda; Lei, Sidong; Vajtai, Robert; Ajayan, Pulickel; Talapatra, Saikat

Response time of a photo detector is one of the crucial aspect of photo-detection. Recently it has been shown that direct band gap of few layered group III-VI materials helps in increased absorption of light thereby enhancing the photo responsive properties of these materials. Ternary system of Copper Indium Selenide has been extensively used in optoelectronics industry and it is expected that 2D layered structure of Copper Indium Selenide will be a key component of future optoelectronics devices based on 2D materials. Here we report fast photo detection in few layers of Copper Indium Selenide (CuIn7Se11) phototransistor. Few-layers of CuIn7Se11 flakes were exfoliated from crystals grown using chemical vapor transport technique. Our photo response characterization indicates responsivity of 104 mA/W with external quantum efficiency exceeding 103. We have found response time of few μs which is one of the fastest response among photodetectors based on 2D materials. We also found specific detectivity of 1012 Jones which is an order higher than conventional photodetectors. A comparison between response times of various layered group III-VI materials will be presented and discussed. This work is supported by the U.S. Army Research Office through a MURI Grant # W911NF-11-1-0362.

Selenium as a Structural Surrogate of Sulfur: Template-Assisted Assembly of Five Types of Tungsten-Iron-Sulfur/Selenium Clusters and the Structural Fate of Chalcogenide Reactants

PubMed Central

Zheng, Bo; Chen, Xu-Dong; Zheng, Shao-Liang; Holm, R. H.

2012-01-01

Syntheses of five types of tungsten-iron-sulfur/selenium clusters–incomplete cubanes, single cubanes, edge-bridged double cubanes (EBDCs), PN-type clusters, and double-cuboidal clusters–have been devised based on the concept of template-assisted assembly. The template reactant is six-coordinate [(Tp*)WVIS3]1−, which in the assembly systems organizes FeII,III and sulfide/selenide into cuboidal [(Tp*)WFe2S3] or cubane [(Tp*)WFe3S3Q] units. With appropriate terminal iron ligation, these units are capable of independent existence or may be transformed into higher nuclearity species. Selenide is used as a surrogate for sulfide in cluster assembly in order to determine by X-ray structures the position occupied by an external chalcogenide nucleophile or an internal chalcogenide atom in product clusters. Specific incorporation of selenide is demonstrated by formation of [WFe3S3Se]2+,3+ cubane cores. Reductive dimerization of the cubane leads to the EBDC core [W2Fe6S6Se2]2+ containing μ4-Se sites. Reaction of these species with HSe− affords the PN-type cores [W2Fe6S6Se3]1+ in which selenide occupies μ6-Se and μ2-Se sites. Reaction of [(Tp*)WS3]1−, FeCl2, and Na2Se results in the double cuboidal [W2Fe4S6Se3]2+,0 core with μ2-Se and μ4-Se bridges. It is highly probable that in analogous sulfide-only assembly systems, external and internal sulfide reactants occupy corresponding positions in cluster products. The results further demonstrate the viability of template-assisted cluster synthesis inasmuch as the reduced (Tp*)WS3 unit is present in all clusters. Structures, zero-field Mössbauer data, and redox potentials are presented for all cluster types. (Tp* = tris(pyrazolyl)hydroborate(1−)) PMID:22424175

Scintigraphic evaluation in musculoskeletal sepsis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merkel, K.D.; Fitzgerald, R.H. Jr.; Brown, M.L.

In this article, the mechanism of technetium, gallium, and indium-labeled white blood cell localization in septic processes is detailed, and the method of interpretation of these three isotopes with relationship to musculoskeletal infection is outlined. Specific clinical application of technetium, gallium, and indium-labeled white blood cell imaging for musculoskeletal sepsis is reviewed.

[Comutagenic action of sodium selenite and caffeine on S. typhimurium TA 1535 with its subsequent treatment by N-nitrosomethylurea].

PubMed

Balanski, R M

1988-01-01

The comutagenic activity of sodium selenite and caffeine was studied by the Ames test. Reproduction of S. typhimurium TA1535 for 4 h at 37 degrees C in the nutrient broth with sodium selenide (5 micrograms/ml) significantly increased sensitivity of bacterial cells to the mutagenic action of 2-3 mM N-nitrosomethylurea (NMU). When using threshold concentrations of NMU the potentiation of mutagenesis reached 625.2%. The addition of 0.19 mg/ml of caffeine to the nutrient medium also led (though the action was less pronounced) to an increase in sensitivity of bacterial cells to the NMU mutagenic action. Reproduction of S. typhimurium TA1535 in the medium containing sodium selenide and caffeine did not cause an increase in the frequency of spontaneous his+-revertant mutations.

Breaking America's dependence on imported molybdenum.

PubMed

Einstein, Andrew J

2009-03-01

Approximately 9 million nuclear cardiology studies performed each year in the U.S. use technetium-99m, which is produced from the decay of molybdenum-99. The fragility of the worldwide technetium-99m supply chain has been underscored by current shortages caused by an unplanned shutdown of Europe's largest reactor. The majority of the U.S. supply derives from a reactor in Canada that is nearing the end of its lifespan and whose planned replacements have been cancelled recently. In this article, the clinical importance of technetium-99m and our tenuous dependence on the foreign supply of molybdenum are addressed, along with potential measures that may be taken to ensure that America's supply chain remains unbroken.

TECHNETIUM RETENTION IN WTP LAW GLASS WITH RECYCLE FLOW-SHEET DM10 MELTER TESTING VSL-12R2640-1 REV 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramowitz, Howard; Brandys, Marek; Cecil, Richard

2012-12-11

Melter tests were conducted to determine the retention of technetium and other volatiles in glass while processing simulated Low Activity Waste (LAW) streams through a DM10 melter equipped with a prototypical off-gas system that concentrates and recycles fluid effiuents back to the melter feed. To support these tests, an existing DM10 system installed at Vitreous State Laboratory (VSL) was modified to add the required recycle loop. Based on the Hanford Tank Waste Treatment and Immobilization Plant (WTP) LAW off-gas system design, suitably scaled versions of the Submerged Bed Scrubber (SBS), Wet Electrostatic Precipitator (WESP), and TLP vacuum evaporator were designed,more » built, and installed into the DM10 system. Process modeling was used to support this design effort and to ensure that issues associated with the short half life of the {sup 99m}Tc radioisotope that was used in this work were properly addressed and that the system would be capable of meeting the test objectives. In particular, this required that the overall time constant for the system was sufficiently short that a reasonable approach to steady state could be achieved before the {sup 99m}Tc activity dropped below the analytical limits of detection. The conceptual design, detailed design, flow sheet development, process model development, Piping and Instrumentation Diagram (P&ID) development, control system design, software design and development, system fabrication, installation, procedure development, operator training, and Test Plan development for the new system were all conducted during this project. The new system was commissioned and subjected to a series of shake-down tests before embarking on the planned test program. Various system performance issues that arose during testing were addressed through a series of modifications in order to improve the performance and reliability of the system. The resulting system provided a robust and reliable platform to address the test objectives.« less

Photoelectric sensor output controlled by eyeball movements

NASA Technical Reports Server (NTRS)

1965-01-01

The difference between the infrared absorption of the iris and infrared reflectivity of the eyeball controls the operation of a device consisting of an infrared source and amplifier, a cadmium selenide infrared sensor, and an infrared filter.

Comparison of early myocardial technetium-99m pyrophosphate uptake to early peaking of creatine kinase and creatine kinase-MB as indicators of early reperfusion in acute myocardial infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondo, M.; Yuzuki, Y.; Arai, H.

1987-10-01

The value of technetium-99m pyrophosphate (Tc-99m-PYP) scintigraphy as an indicator of reperfusion 2.8 to 8 hours after the onset of symptoms of acute myocardial infarction was compared with the value of early peak creatine kinase (CK) and CK-MB release within 16 hours after the onset of symptoms. In 29 patients who received thrombolytic therapy, recanalization was seen (group 1) and in 7 it was not (group 2). In 23 patients (79%) in group 1 scintigraphic findings were positive and in all 7 in group 2 they were negative. In 15 patients (52%) in group 1 and 1 patient (14%) inmore » group 2, CK reached its peak level within 16 hours. In 20 patients (69%) in group 1 and 3 (43%) in group 2 the CK-MB level reached a peak within 16 hours. The sensitivity, specificity and predictive accuracy of positive results of early Tc-99m-PYP scintigraphy in predicting the reperfusion were 79%, 100% and 83%. These values are significantly higher than or similar to those of early peaking of CK and CK-MB release. In contrast to measurements of enzyme release, reperfusion data for Tc-99m-PYP scintigraphy are available immediately after thrombolytic therapy. Therefore, early Tc-99m-PYP scintigraphy (3 to 8 hours after onset of symptoms) is valuable as a noninvasive technique for early diagnosis of reperfusion.« less

Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

NASA Astrophysics Data System (ADS)

Lv, Haitao; Duan, Ke; Shan, Hu

2018-04-01

Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities, but its molecular weight was greatly high which influenced the activity. Organic Se had higher biological activities and was safer than inorganic Se species. In the present study, Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H2O2 and ascorbic acid. By single factor and orthogonal experiments, the optimal degradation conditions were reaction time of 2 h, reaction temperature of 50°C, H2O2/ascorbic acid (n/n=1:1) concentration of 15 mmol L-1, and solid-liquid ratio of 1:50 (g mL-1). Then, the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method. The selenium content was 1137.29 μg g-1, while the content of sulfate radical had no change. IR spectra indicated that the selenite ester group was formed. Degraded polysaccharide selenide was characterized and evaluated for antioxidant, antifungal and antibacterial activities. The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and ·OH free radical. It had significant antibacterial properties for Escherichia coli, Bacillus subtilis and Salmonella spp., and it also had significant antifungal properties for Apple anthrax. The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides. It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

Real-time observation of Cu2ZnSn(S,Se)4 solar cell absorber layer formation from nanoparticle precursors.

PubMed

Mainz, Roland; Walker, Bryce C; Schmidt, Sebastian S; Zander, Ole; Weber, Alfons; Rodriguez-Alvarez, Humberto; Just, Justus; Klaus, Manuela; Agrawal, Rakesh; Unold, Thomas

2013-11-07

The selenization of Cu-Zn-Sn-S nanocrystals is a promising route for the fabrication of low-cost thin film solar cells. However, the reaction pathway of this process is not completely understood. Here, the evolution of phase formation, grain size, and elemental distributions is investigated during the selenization of Cu-Zn-Sn-S nanoparticle precursor thin films by synchrotron-based in situ energy-dispersive X-ray diffraction and fluorescence analysis as well as by ex situ electron microscopy. The precursor films are heated in a closed volume inside a vacuum chamber in the presence of selenium vapor while diffraction and fluorescence signals are recorded. The presented results reveal that during the selenization the cations diffuse to the surface to form large grains on top of the nanoparticle layer and the selenization of the film takes place through two simultaneous reactions: (1) a direct and fast formation of large grained selenides, starting with copper selenide which is subsequently transformed into Cu2ZnSnSe4; and (2) a slower selenization of the remaining nanoparticles. As a consequence of the initial formation of copper selenides at the surface, the subsequent formation of CZTSe starts under Cu-rich conditions despite an overall Cu-poor composition of the film. The implications of this process path for the film quality are discussed. Additionally, the proposed growth model provides an explanation for the previously observed accumulation of carbon from the nanoparticle precursor beneath the large grained layer.

The Geochemistry of Technetium: A Summary of the Behavior of an Artificial Element in the Natural Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Icenhower, Jonathan P.; Qafoku, Nikolla; Martin, Wayne J.

Interest in the chemistry of technetium has only increased since its discovery in 1937, mainly because of the large and growing inventory of 99Tc generated during fission of 235U, its environmental mobility in oxidizing conditions, and its potential radiotoxicity. For every ton of enriched uranium fuel (3% 235U) that is consumed at a typical burn-up rate, nearly 1 kg of 99Tc is generated. Thus, the mass of 99Tc produced since 1993 has nearly quadrupled, and will likely to continue to increase if more emphasis is placed on nuclear power to slow the accumulation of atmospheric greenhouse gases. In order tomore » gain a comprehensive understanding of the interaction of 99Tc and the natural environment, we review the sources of 99Tc in the nuclear fuel cycle, its chemical properties, radiochemistry, and biogeochemical behavior. We include an evaluation of the use of Re as a chemical analog of Tc, as well as a summary of the redox potential, thermodynamics, sorption, colloidal behavior, and interaction of humic substances with Tc, and the potential for re-oxidation and remobilization of Tc(IV). What emerges is a more complicated picture of Tc behavior than that of an easily tractable transition of Tc(VII) to Tc(IV) with consequent immobilization. Reducing conditions (+200 to +100 mV Eh) are generally thought necessary to cause reduction of Tc(VII) to Tc(IV), but far more important are the presence of reducing agents, such as Fe(II) sorbed onto mineral grains. Catalysis of Tc(VII) by surface-mediated Fe(II) will bring the mobile Tc(VII) species to a lower oxidation state and will form the relatively insoluble Tc(IV)O2∙nH2O, but even as a solid, equilibrium concentrations of aqueous Tc are nearly a factor of 20× above the EPA set drinking water standards. However, sequestration of Tc(IV) into Fe(III)-bearing phases, such as goethite or other hydrous oxyhydroxides of iron, may ameliorate concerns over the mobility of Tc. Further, the outcome of many studies on

Oxidation of aqueous polyselenide solutions. A mechanistic pulse radiolysis study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldbach, A.; Saboungi, M.L.; Johnson, J.A.

2000-05-04

The oxidation of aqueous polyselenide solutions was studied by pulse radiolysis in the presence of N{sub 2}O at pH 12.3; the hydroxyl radical OH was the predominant oxidant, while hydrogen selenide anions HSe{sup {minus}} and triselenide dianions Se{sub 3}{sup 2{minus}} were the major selenide species in the starting solution. The progress of the oxidation was monitored by optical spectroscopy. Transient polyselenides appeared immediately after the electron pulse and rapidly proceeded to form adducts with HSe{sup {minus}}, i.e., HSe{sub 2}{sup 2{minus}} and H{sub 2}Se{sub 2}{sup {minus}}, and a fairly long-lived intermediate that was identified as the diselenide radical anion Se{sub 2}{supmore » {minus}}. These radicals recombine to give eventually the tetraselenide dianion, Se{sub 4}{sup 2{minus}}.« less

SKYLAB (SL)-3 - EXPERIMENT HARDWARE

NASA Image and Video Library

1973-11-08

S74-19677 (April 1974) --- This crystal of Germanium Selenide (GeSe) was grown under weightless conditions in an electric furnace aboard the Skylab space station. Experiment M556, Vapor Growth of IV-VI Compounds, was conducted as a comparative test of GeSe crystals grown on Earth and those grown in a weightless environment. Skylab postflight results indicate that crystals grown in a zero-gravity situation demonstrate greater growth and better composite structure than those grown in ground-bases laboratories. The GeSe crystal shown here is 20 millimeters long, the largest crystal ever grown on Earth or in space. Principal Investigator for Experiment M556 is Dr. Harry Wiedemaier, Rensselaer Polytechnic Institute, Troy, New York. (See NASA photograph S74-19676 for an example of an Earth-grown Germanium Selenide crystal.) Photo credit: NASA

The Chemical Nature of Mercury in Human Brain Following Poisoning or Environmental Exposure

PubMed Central

2010-01-01

Methylmercury is among the most potentially toxic species to which human populations are exposed, both at high levels through poisonings and at lower levels through consumption of fish and other seafood. However, the molecular mechanisms of methylmercury toxicity in humans remain poorly understood. We used synchrotron X-ray absorption spectroscopy (XAS) to study mercury chemical forms in human brain tissue. Individuals poisoned with high levels of methylmercury species showed elevated cortical selenium with significant proportions of nanoparticulate mercuric selenide plus some inorganic mercury and methylmercury bound to organic sulfur. Individuals with a lifetime of high fish consumption showed much lower levels of mercuric selenide and methylmercury cysteineate. Mercury exposure did not perturb organic selenium levels. These results elucidate a key detoxification pathway in the central nervous system and provide new insights into the appropriate methods for biological monitoring. PMID:22826746

Calculation of therapeutic activity of radioiodine in Graves' disease by means of Marinelli's formula, using technetium (99mTc) scintigraphy.

PubMed

Szumowski, Piotr; Mojsak, Małgorzata; Abdelrazek, Saeid; Sykała, Monika; Amelian-Fiłonowicz, Anna; Jurgilewicz, Dorota; Myśliwiec, Janusz

2016-12-01

The therapeutic activity of 131 I administered to patients with Graves' disease can be calculated by means of Marinelli's formula. The thyroidal iodine uptake ( 131 IU max ) needed for the calculation is usually determined with the use of 131 I. The purpose of the paper was to estimate 131 IU max on the basis of technetium uptake in the thyroid at 20 min ( 99m TcU 20min ). Eighty patients suffering from Graves' disease were qualified for radioiodine therapy with measurement of fT 4 , fT 3 , thyroid-stimulating hormone and its receptor (TRAb). Prior to the treatment, all the patients were euthyroid. 131 IU max for each patient was determined according to the levels of 131 I after 24 h ( 131 IU 24h ), while effective half-life (T eff ) according to the measurements of 131 IU 24h and 131 I uptake after 48 h ( 131 IU 48h ). Additionally, on the day before measuring 131 IU 24h , 99m TcU 20min was calculated for each patient. It was demonstrated that there existed a correlation, with statistical significance at p < 0.05, between the following pairs of values: TRAb and 131 IU 24h , TRAb and 99m TcU 20min , and 99m TcU 20min and 131 IU 24h . The interdependence between 131 IU 24h and 99m TcU 20min at the level of significance p < 0.05 is described by the following algorithms: 131 IU 24h  = 17.72 × ln ( 99m TcU 20min ) + 30.485, if TRAb < 10 IU/ml, and 131 IU 24h  = 18.03 × ln ( 99m TcU 20min ) + 38.726, if TRAb > 10 IU/ml. It is possible to predict thyroid iodine uptake 131 IU 24h in Graves' disease on the basis of measuring the uptake of 99m TcU 20min . This shortens the time necessary for diagnosis and enables the calculation of 131 I activity using Marinelli's formula.

Value of imaging studies after a first febrile urinary tract infection in young children: data from Italian renal infection study 1.

PubMed

Montini, Giovanni; Zucchetta, Pietro; Tomasi, Lisanna; Talenti, Enrico; Rigamonti, Waifro; Picco, Giorgio; Ballan, Alberto; Zucchini, Andrea; Serra, Laura; Canella, Vanna; Gheno, Marta; Venturoli, Andrea; Ranieri, Marco; Caddia, Valeria; Carasi, Carla; Dall'amico, Roberto; Hewitt, Ian

2009-02-01

We examined the diagnostic accuracy of routine imaging studies (ultrasonography and micturating cystography) for predicting long-term parenchymal renal damage after a first febrile urinary tract infection. This study addressed the secondary objective of a prospective trial evaluating different antibiotic regimens for the treatment of acute pyelonephritis. Data for 300 children < or =2 years of age, with normal prenatal ultrasound results, who completed the diagnostic follow-up evaluation (ultrasonography and technetium-99m-dimercaptosuccinic acid scanning within 10 days, cystography within 2 months, and repeat technetium-99m-dimercaptosuccinic acid scanning at 12 months to detect scarring) were analyzed. Outcome measures were sensitivity, specificity, and negative and positive predictive values for ultrasonography and cystography in predicting parenchymal renal damage on the 12-month technetium-99m-dimercaptosuccinic acid scans. The kidneys and urinary tracts were mostly normal. The acute technetium-99m-dimercaptosuccinic acid scans showed pyelonephritis in 54% of cases. Renal scarring developed in 15% of cases. The ultrasonographic and cystographic findings were poor predictors of long-term damage, showing minor sonographic abnormalities for 12 and reflux for 23 of the 45 children who subsequently developed scarring. The benefit of performing ultrasonography and scintigraphy in the acute phase or cystourethrography is minimal. Our findings support (1) technetium-99m-dimercaptosuccinic acid scintigraphy 6 months after infection to detect scarring that may be related to long-term hypertension, proteinuria, and renal function impairment (although the degree of scarring was generally minor and did not impair renal function) and (2) continued surveillance to identify recurrent urinary tract infections that may warrant further investigation.

Lead selenide quantum dot polymer nanocomposites

NASA Astrophysics Data System (ADS)

Waldron, Dennis L.; Preske, Amanda; Zawodny, Joseph M.; Krauss, Todd D.; Gupta, Mool C.

2015-02-01

Optical absorption and fluorescence properties of PbSe quantum dots (QDs) in an Angstrom Bond AB9093 epoxy polymer matrix to form a nanocomposite were investigated. To the authors’ knowledge, this is the first reported use of AB9093 as a QD matrix material and it was shown to out-perform the more common poly(methyl methacrylate) matrix in terms of preserving the optical properties of the QD, resulting in the first reported quantum yield (QY) for PbSe QDs in a polymer matrix, 26%. The 1-s first excitonic absorption peak of the QDs in a polymer matrix red shifted 65 nm in wavelength compared to QDs in a hexane solution, while the emission peak in the polymer matrix red shifted by 38 nm. The fluorescence QY dropped from 55% in hexane to 26% in the polymer matrix. A time resolved fluorescence study of the QDs showed single exponential lifetimes of 2.34 and 1.34 μs in toluene solution and the polymer matrix respectively.

Mercury Cadmium Selenide for Infrared Detection

DTIC Science & Technology

2013-06-01

were grown using elemental mercury (Hg), cadmium (Cd), and selenium (Se) sources. The beam equiva- lent pressure ( BEP ) emanating from all sources was...flux), the BEP measured for the cracker source was found to vary with the cracking zone temperature, tracking with the data found in Ref. 7. This sug...The Se BEP measured for the typical cracking zone temperature of 800 C was found to be close to a factor of two lower than at the typical effusion cell

Characterization of zinc selenide single crystals

NASA Technical Reports Server (NTRS)

Gerhardt, Rosario A.

1996-01-01

ZnSe single crystals of high quality and low impurity levels are desired for use as substrates in optoelectronic devices. This is especially true when the device requires the formation of homoepitaxial layers. While ZnSe is commercially available, it is at present extremely expensive due to the difficulty of growing single crystal boules with low impurity content and the resultant low yields. Many researchers have found it necessary to heat treat the crystals in liquid Zn in order to remove the impurities, lower the resistivity and activate the photoluminescence at room temperature. The physical vapor transport method (PVT) has been successfully used at MSFC to grow many single crystals of II-VI semiconducting materials including ZnSe. The main goal at NASA has been to try to establish the effect of gravity on the growth parameters. To this effect, crystals have been grown vertically upwards or horizontally. Both (111) and (110) oriented ZnSe crystals have been obtained via unseeded PVT growth. Preliminary characterization of the horizontally grown crystals has revealed that Cu is a major impurity and that the low temperature photoluminescence spectra is dominated by the copper peak. The ratio of the copper peak to the free exciton peak is being used to determine variations in composition throughout the crystal. It was the intent of this project to map the copper composition of various crystals via photoluminescence first, then measure their electrical resistivity and capacitance as a function of frequency before proceeding with a heat treatment designed to remove the copper impurities. However, equipment difficulties with the photoluminescence set up, having to establish a procedure for measuring the electrical properties of the as-grown crystals and time limitations made us re-evaluate the project goals. Vertically grown samples designated as ZnSe-25 were chosen to be measured electrically since they were not expected to show as much variation in their composition through their cross-section as the horizontally grown samples.

Process for the recovery of strontium from acid solutions

DOEpatents

Horwitz, E. Philip; Dietz, Mark L.

1992-01-01

The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid.

Technetium-99m tetrofosmin rest/stress myocardial SPET with a same-day 2-hour protocol: comparison with coronary angiography. A Spanish-Portuguese multicentre clinical trial.

PubMed

Montz, R; Perez-Castejón, M J; Jurado, J A; Martín-Comín, J; Esplugues, E; Salgado, L; Ventosa, A; Cantinho, G; Sá, E P; Fonseca, A T; Vieira, M R

1996-06-01

Technetium-99m tetrofosmin (Myoview) has unique properties for myocardial perfusion imaging very early after injection of the tracer. We used a very short same-day rest/stress protocol, to be performed within 2 h and evaluated its diagnostic accuracy. The study included 144 patients from seven Spanish and four Portuguese centres with a diagnosis of uncomplicated coronary artery disease (CAD); 78 patients (54%) had no history of prior myocardial infarction. Patients were injected with /=50%) was achieved with a sensitivity of 64% for the left anterior descending artery, 49% for the left circumflex artery and 86% for the right coronary artery, and an accuracy of 71%, 72% and 73% respectively. Concordance of SPET and CA was 62% for single-vessel disease and 68% for multivessel disease. In conclusion, this Spanish-Portuguese multicentre clinical trial confirmed, in a considerable number of patients who underwent coronary angiography, the feasibility of 99mTc tetrofosmin (Myoview) rest/stress myocardial SPET using a very short protocol (2 h).

Rare-earth transition-metal gallium chalcogenides RE3MGaCh7 (M=Fe, Co, Ni; Ch=S, Se)

NASA Astrophysics Data System (ADS)

Rudyk, Brent W.; Stoyko, Stanislav S.; Oliynyk, Anton O.; Mar, Arthur

2014-02-01

Six series of quaternary rare-earth transition-metal chalcogenides RE3MGaCh7 (M=Fe, Co, Ni; Ch=S, Se), comprising 33 compounds in total, have been prepared by reactions of the elements at 1050 °C (for the sulphides) or 900 °C (for the selenides). They adopt noncentrosymmetric hexagonal structures (ordered Ce3Al1.67S7-type, space group P63, Z=2) with cell parameters in the ranges of a=9.5-10.2 Å and c=6.0-6.1 Å for the sulphides and a=10.0-10.5 Å and c=6.3-6.4 Å for the selenides as refined from powder X-ray diffraction data. Single-crystal structures were determined for five members of the sulphide series RE3FeGaS7 (RE=La, Pr, Tb) and RE3CoGaS7 (RE=La, Tb). The highly anisotropic crystal structures consist of one-dimensional chains of M-centred face-sharing octahedra and stacks of Ga-centred tetrahedra all pointing in the same direction. Magnetic measurements on the sulphides reveal paramagnetic behaviour in some cases and long-range antiferromagnetic behaviour with low Néel temperatures (15 K or lower) in others. Ga L-edge XANES spectra support the presence of highly cationic Ga tetrahedral centres with a tendency towards more covalent Ga-Ch character on proceeding from the sulphides to the selenides. Band structure calculations on La3FeGaS7 indicate that the electronic structure is dominated by Fe 3d-based states near the Fermi level.

Infrared spectra alteration in water proximate to the palms of therapeutic practitioners.

PubMed

Schwartz, Stephan A; De Mattei, Randall J; Brame, Edward G; Spottiswoode, S James P

2015-01-01

Through standard techniques of infrared (IR) spectrophotometry, sterile water samples in randomly selected sealed vials evidence alteration of infrared (IR) spectra after being proximate to the palms of the hands of both Practicing and Non-practicing Therapy Practitioners, each of whom employed a personal variation of the Laying-on-of-Hands/Therapeutic Touch processes. This pilot study presents 14 cases, involving 14 Practitioners and 14 Recipients. The first hypothesis, that a variation in the spectra of all (84) Treated spectra compared with all (57) Control spectra would be observed in the 2.5-3.0µm range, was confirmed (P = .02). Overall, 10% (15) of the spectra were done using a germanium internal reflection element (IRE), and 90% of the spectra (126) were done with a zinc selenide IRE. The difference in refractive index between the two IREs skews the data. The zinc selenide IRE spectra alone yield P = .005. The authors believe the most representative evidence for the effect appeared in the sample group of Treated vs Calibration Controls using the zinc selenide IRE (P = .0004). The second hypothesis, that there existed a direct relationship between intensity of effect and time of exposure, was not confirmed. This study replicates earlier findings under conditions of blindness, randomicity, and several levels of controls. Environmental factors are considered as explanations for the observed IR spectrum alteration, including temperature, barometric pressure, and variations dependent on sampling order. They do not appear to explain the effect. Copyright © 2015. Published by Elsevier Inc.

Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

DOE Office of Scientific and Technical Information (OSTI.GOV)

1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic

2008-02-26

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented bymore » products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.« less

Magnetic core mesoporous silica nanoparticles doped with dacarbazine and labelled with 99mTc for early and differential detection of metastatic melanoma by single photon emission computed tomography.

PubMed

Portilho, Filipe Leal; Helal-Neto, Edward; Cabezas, Santiago Sánchez; Pinto, Suyene Rocha; Dos Santos, Sofia Nascimento; Pozzo, Lorena; Sancenón, Félix; Martínez-Máñez, Ramón; Santos-Oliveira, Ralph

2018-02-27

Cancer is responsible for more than 12% of all causes of death in the world, with an annual death rate of more than 7 million people. In this scenario melanoma is one of the most aggressive ones with serious limitation in early detection and therapy. In this direction we developed, characterized and tested in vivo a new drug delivery system based on magnetic core-mesoporous silica nanoparticle that has been doped with dacarbazine and labelled with technetium 99 m to be used as nano-imaging agent (nanoradiopharmaceutical) for early and differential diagnosis and melanoma by single photon emission computed tomography. The results demonstrated the ability of the magnetic core-mesoporous silica to be efficiently (>98%) doped with dacarbazine and also efficiently labelled with 99mTc (technetium 99 m) (>99%). The in vivo test, using inducted mice with melanoma, demonstrated the EPR effect of the magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable when injected intratumorally and the possibility to be used as systemic injection too. In both cases, magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable showed to be a reliable and efficient nano-imaging agent for melanoma.

Geochemical behavior of Cs, Sr, Tc, Np, and U in saline groundwaters: Sorption experiments on shales and their clay mineral components: Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, R.E.; Arnold, W.D.; Ho, P.C.

1987-11-01

The Sedimentary Rock Program at the Oak Ridge National Laboratory is investigating shale to determine its potential suitability as a host rock for the disposal of high-level radioactive wastes (HLW). In support of this program, preliminary studies were carried out on sorption of cesium, strontium, technetium, neptunium, and uranium onto Chattanooga (Upper Dowelltown), Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales under oxic conditions (air present). Three simulated groundwaters were used. One of the groundwaters was a synthetic brine made up to simulate highly saline groundwaters in the Pumpkin Valley Shale. The second was a 100/1 dilution of thismore » groundwater and the third was 0.03 M NaHCO/sub 3/. Moderate to significant sorption was observed under most conditions for all of the tested radionuclides except technetium. Moderate technetium sorption occurred on Upper Dowelltown Shale, and although technetium sorption was low on the other shales, it was higher than expected for Tc(VII), present as the anion TcO/sub 4//sup -/. Little sorption of strontium onto the shales was observed from the concentrated saline groundwater. These data can be used in a generic fashion to help assess the sorption characteristics of shales in support of a national survey. 10 refs., 4 figs., 23 tabs.« less

Rhenium volatilisation as caesium perrhenate from simulated vitrified high level waste from a melter crucible

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, T.A.; Short, R.J.; Gribble, N.R.

2013-07-01

The Waste Vitrification Plant (WVP) converts Highly Active Liquor (HAL) from spent nuclear fuel reprocessing into a stable vitrified product. Recently WVP have been experiencing accumulation of solids in their primary off gas (POG) system leading to potential blockages. Chemical analysis of the blockage material via Laser Induced Breakdown Spectroscopy (LIBS) has shown it to exclusively consist of caesium, technetium and oxygen. The solids are understood to be caesium pertechnetate (CsTcO{sub 4}), resulting from the volatilisation of caesium and technetium from the high level waste glass melt. Using rhenium as a chemical surrogate for technetium, a series of full scalemore » experiments have been performed in order to understand the mechanism of rhenium volatilisation as caesium perrhenate (CsReO{sub 4}), and therefore technetium volatilisation as CsTcO{sub 4}. These experiments explored the factors governing volatilisation rates from the melt, potential methods of minimising the amount of volatilisation, and various strategies for mitigating the deleterious effects of the volatile material on the POG. This paper presents the results from those experiments, and discusses potential methods to minimise blockages that can be implemented on WVP, so that the frequency of the CsTcO{sub 4} blockages can be reduced or even eradicated altogether. (authors)« less

A Biphasic Ligand Exchange Reaction on Cdse Nanoparticles: Introducing Undergraduates to Functionalizing Nanoparticles for Solar Cells

ERIC Educational Resources Information Center

Zemke, Jennifer M.; Franz, Justin

2016-01-01

Semiconductor nanoparticles, including cadmium selenide (CdSe) particles, are attractive as light harvesting materials for solar cells. In the undergraduate laboratory, the size-tunable optical and electronic properties can be easily investigated; however, these nanoparticles (NPs) offer another platform for application-based tunability--the NP…

Liquid chromatographic extraction medium

DOEpatents

Horwitz, E. Philip; Dietz, Mark L.

1994-01-01

A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

Process for the recovery of strontium from acid solutions

DOEpatents

Horwitz, E.P.; Dietz, M.L.

1992-03-31

The invention is a process for selectively extracting strontium and technetium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant is a macrocyclic polyether in a diluent which is insoluble in water, but which will itself dissolve a small amount of water. The process will extract strontium and technetium values from nitric acid solutions which are up to 6 molar in nitric acid. 5 figs.

Method for liquid chromatographic extraction of strontium from acid solutions

DOEpatents

Horwitz, E. Philip; Dietz, Mark L.

1992-01-01

A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

Techniques for Loading Technetium-99m and Rhenium-186/188 Radionuclides into Preformed Liposomes for Diagnostic Imaging and Radionuclide Therapy.

PubMed

Goins, Beth; Bao, Ande; Phillips, William T

2017-01-01

Liposomes can serve as carriers of radionuclides for diagnostic imaging and therapeutic applications. Herein, procedures are outlined for radiolabeling liposomes with the gamma-emitting radionuclide, technetium-99m ( 99m Tc), for noninvasive detection of disease and for monitoring the pharmacokinetics and biodistribution of liposomal drugs, and/or with therapeutic beta-emitting radionuclides, rhenium-186/188 ( 186/188 Re), for radionuclide therapy. These efficient and practical liposome radiolabeling methods use a post-labeling mechanism to load 99m Tc or 186/188 Re into preformed liposomes prepared in advance of the labeling procedure. For all liposome radiolabeling methods described, a lipophilic chelator is used to transport 99m Tc or 186/188 Re across the lipid bilayer of the preformed liposomes. Once within the liposome interior, the pre-encapsulated glutathione or ammonium sulfate (pH) gradient provides for stable entrapment of the 99m Tc and 186/188 Re within the liposomes. In the first method, 99m Tc is transported across the lipid bilayer by the lipophilic chelator, hexamethylpropyleneamine oxime (HMPAO) and 99m Tc-HMPAO becomes trapped by interaction with the pre-encapsulated glutathione within the liposomes. In the second method, 99m Tc or 186/188 Re is transported across the lipid bilayer by the lipophilic chelator, N,N-bis(2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA), and 99m Tc-BMEDA or 186/188 Re-BMEDA becomes trapped by interaction with pre-encapsulated glutathione within the liposomes. In the third method, an ammonium sulfate (pH) gradient loading technique is employed using liposomes with an extraliposomal pH of 7.4 and an interior pH of 5.1. BMEDA, which is lipophilic at pH 7.4, serves as a lipophilic chelator for 99m Tc or 186/188 Re to transport the radionuclides across the lipid bilayer. Once within the more acidic liposome interior, 99m Tc/ 186/188 Re-BMEDA complex becomes protonated and more hydrophilic, which results in stable

Temperature Dependent Photoluminescence of CuInS2 with ZnS Capping

DTIC Science & Technology

2014-05-11

cadmium or zinc like cadmium selenide. The optical properties of core-type nanocrystals can be fine-tuned by changing the quantum dot size. Core...Physics Department To August 2011 University of Notre Dame, South Bend, Indiana - Computational work involving the half-life of Fe60 - Data

A Photoelectrochemical Solar Cell: An Undergraduate Experiment.

ERIC Educational Resources Information Center

Boudreau, Sharon M.; And Others

1983-01-01

Preparation and testing of a cadmium selenide photoelectrical solar cell was introduced into an environmental chemistry course to illustrate solid state semiconductor and electrochemical principles. Background information, procedures, and results are provided for the experiment which can be accomplished in a three- to four-hour laboratory session…

Oven rack having integral lubricious, dry porcelain surface

DOEpatents

Ambrose, Jeffrey A; Mackiewicz-Ludtka, Gail; Sikka, Vinod K; Qu, Jun

2014-06-03

A lubricious glass-coated metal cooking article capable of withstanding repeated heating and cooling between room temperature and at least 500.degree. F. without chipping or cracking the glass coating, wherein the glass coating includes about 0.1 to about 20% by weight of a homogeneously distributed dry refractory lubricant material having a particle size less than about 200 .mu.m. The lubricant material is selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (FV) sulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide, tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si.sub.3N.sub.4); TiN; TiC; TiCN; TiO.sub.2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO.sub.2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof.

Investigating different mechanisms for biogenic selenite transformations: Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica

USGS Publications Warehouse

Pearce, C.I.; Pattrick, R.A.D.; Law, N.; Charnock, J.M.; Coker, V.S.; Fellowes, J.W.; Oremland, R.S.; Lloyd, J.R.

2009-01-01

The metal-reducing bacteria Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica, use different mechanisms to transform toxic, bioavailable sodium selenite to less toxic, non-mobile elemental selenium and then to selenide in anaerobic environments, offering the potential for in situ and ex situ bioremediation of contaminated soils, sediments, industrial effluents, and agricultural drainage waters. The products of these reductive transformations depend on both the organism involved and the reduction conditions employed, in terms of electron donor and exogenous extracellular redox mediator. The intermediary phase involves the precipitation of elemental selenium nanospheres and the potential role of proteins in the formation of these structures is discussed. The bionanomineral phases produced during these transformations, including both elemental selenium nanospheres and metal selenide nanoparticles, have catalytic, semiconducting and light-emitting properties, which may have unique applications in the realm of nanophotonics. This research offers the potential to combine remediation of contaminants with the development of environmentally friendly manufacturing pathways for novel bionanominerals. ?? 2009 Taylor & Francis.

Detection of intestinal obstruction by radionuclide scan: case report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaudhuri, T.K.

1976-11-01

The value of /sup 99m/Technetium-pertechnetate abdomen scan has recently been established in the diagnosis of Meckel's diverticulum, intussusception, and inflamed appendix. The purpose of this paper is to report a case with small intestinal obstruction secondary to fibrous adhesions which resulted from a previous surgery, in whom a /sup 99m/Technetium-pertechnetate abdomen scan showed increased radionuclide concentration in the area of dilated loop of bowel proximal to the site of obstruction.

Liquid chromatographic extraction medium

DOEpatents

Horwitz, E.P.; Dietz, M.L.

1994-09-13

A method and apparatus are disclosed for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water. 1 fig.

Role of nuclear medicine in clinical urology and nephrology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaufox, M.D.; Fine, E.; Lee, H.B.

The application of radionuclide studies to nephrologic and urologic practice has reached a measurable degree of maturity during the past several years. In spite of this, the utilization of these techniques in many institutions in the United States continues to be far less frequent than one would expect from the clinical advantages. The aim of this editorial is to try to place the role of nuclear medicine in urology and nephrology in perspective. At the present time, in spite of the large number of renal agents that have been developed, there is no practical ideal radiopharmaceutical that can serve asmore » a universal agent. Arbitrarily, one may reduce the chief armamentarium to only four radiopharmaceuticals; technetium-99m DTPA, I-131 OIH (orthoiodohippurate), technetium-99m glucoheptonate and technetium-99m DMSA. These agents are discussed with their relative advantages and disadvantages.« less

Sodalite as a vehicle to increase Re retention in waste glass simulant during vitrification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luksic, Steven A.; Riley, Brian J.; Parker, Kent E.

Technetium retention during Hanford waste vitrification can be increased by inhibiting technetium volatility from the waste glass melter. Incorporating technetium into a mineral phase, such as sodalite, is one way to achieve this. Rhenium-bearing sodalite was tested as a vehicle to transport perrhenate (ReO4-), a nonradioactive surrogate for pertechnetate (TcO4-), into high-level (HLW) and low-activity waste (LAW) glasses. After melting feeds of these two glasses, the retention of rhenium was measured and compared with the rhenium retention in glass prepared from a feed containing Re2O7 as a standard. The rhenium retention was 21% higher for HLW glass and 85% highermore » for LAW glass when added to samples in the form of sodalite as opposed to when it was added as Re2O7, demonstrating the efficacy of this type of an approach.« less

Increased technetium-99 m hydroxy diphosphonate soft tissue uptake on bone scintigraphy in chronic kidney disease patients with secondary hyperparathyroidism: correlation with hyperphosphataemia.

PubMed

Enevoldsen, Lotte Hahn; Heaf, James; Højgaard, Liselotte; Zerahn, Bo; Hasbak, Philip

2017-03-01

In bone scan patients with dialysis-treated chronic kidney disease (CKD) and hyperparathyroidism, soft tissue accumulation of technetium-99 m hydroxy/methylene diphosphonate (Tc-99 m-HDP/MDP) has been reported primarily in case reports and usually explained by hypercalcaemia and/or hyperphosphataemia. As human vascular smooth muscle cells produce hydroxyapatite during cell culture with increased phosphate levels and as Tc-99 m-HDP/MDP primarily binds to hydroxyapatite, we hypothesized that soft tissue accumulation would be found in patients with hyperphosphataemia. We identified 63 CKD patients diagnosed with secondary hyperparathyroidism admitted for Tc-99 m-HDP bone scan. Baseline characteristics and mean concentrations of biochemical markers (including P-calcium and P-phosphate) taken 0-3 months prior to the bone scans were collected. Soft tissue uptake was detected on bone scans in 37 of 63 (59%) patients. Primary locations were in the heart (27/37 = 73%), muscles (12/37 = 32%), lung (9/37 = 24%) and gastrointestinal tract (6/37 = 16%), and 13 of 37 (35%) patients had simultaneous uptake in more than one location. Regarding biochemical markers, patients with soft tissue uptake only differed from patients without in terms of plasma phosphate levels (1·95 ± 0·15 (n = 37) versus 1·27 ± 0·08 (n = 26), P = 0·0012). All patients with myocardial uptake (n = 27) had a coronary arteriography-verified history of coronary artery disease (CAD), whereas CAD was only present in six of the 36 patients without myocardial uptake. In conclusion, dialysis-treated CKD patients with secondary hyperparathyroidism have a high incidence of soft tissue uptake, and this finding is strongly correlated with elevated phosphate, but not calcium values. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Biliary excretion of technetium-99m-sestamibi in wild-type dogs and in dogs with intrinsic (ABCB1-1Delta mutation) and extrinsic (ketoconazole treated) P-glycoprotein deficiency.

PubMed

Coelho, J C; Tucker, R; Mattoon, J; Roberts, G; Waiting, D K; Mealey, K L

2009-10-01

P-glycoprotein (P-gp), the product of ABCB1 gene, is thought to play a role in the biliary excretion of a variety of drugs, but specific studies in dogs have not been performed. Because a number of endogenous (ABCB1 polymorphisms) and exogenous (pharmacological P-gp inhibition) factors can interfere with normal P-gp function, a better understanding of P-gp's role in biliary drug excretion is crucial in preventing adverse drug reactions and drug-drug interactions in dogs. The objectives of this study were to compare biliary excretion of technetium-99m-sestamibi ((99m)Tc-MIBI), a radio-labelled P-gp substrate, in wild-type dogs (ABCB1 wild/wild), and dogs with intrinsic and extrinsic deficiencies in P-gp function. Dogs with intrinsic P-gp deficiency included ABCB1 mut/mut dogs, and dogs with presumed intermediate P-gp phenotype (ABCB1 mut/wild). Dogs with extrinsic P-gp deficiency were considered to be ABCB1 wild/wild dogs treated with the P-gp inhibitor ketoconazole (5 mg/kg PO q12h x 9 doses). Results from this study indicate that ABCB1 mut/mut dogs have significantly decreased biliary excretion of (99m)Tc-MIBI compared with ABCB1 wild/wild dogs. Treatment with ketoconazole significantly decreased biliary excretion of (99m)Tc-MIBI in ABCB1 wild/wild dogs. P-gp appears to play an important role in the biliary excretion of (99m)Tc-MIBI in dogs. It is likely that concurrent administration of a P-gp inhibitor such as ketoconazole will decrease P-gp-mediated biliary excretion of other substrate drugs as well.

Biochemical Connections Between the Atmosphere and the Ocean

NASA Astrophysics Data System (ADS)

Liss, P. S.

INTRODUCTION THE CHEMICAL COMPOSITION OF THE EARTH'S ATMOSPHERE AIR-SEA EXCHANGE OF GASES OF IMPORTANCE Ozone Manmade Carbon Dioxide Dimethyl Sulphide Dimethyl Selenide Ammonia IMPACT OF ATMOSPHERIC DUST ON OCEAN BIOCHEMISTRY GLOBAL PERSPECTIVES ON BIOGEOCHEMICAL FLUXES ACROSS THE AIR-SEA INTERFACE DMS and the CLAW Hypothesis Iron REFERENCES

The Relation of Batteries to Explosives.

DTIC Science & Technology

1980-09-01

aqueous systems was discussed for the mercury and lead acid systems. If initiation of an explosive reaction does not occur, these gases can 4-2 - ~W...Interfacial Electrochemistry, 53, (1974), 329-333. 2 5Mills, K. C., Therodynamic Data for Inorganic Sulphides , Selenides and Tellurides, 1974, p. 26

Chemical Forms of Selenium in the Metal-Resistant Bacterium Ralstonia metallidurans CH34 Exposed to Selenite and Selenate

PubMed Central

Sarret, Géraldine; Avoscan, Laure; Carrière, Marie; Collins, Richard; Geoffroy, Nicolas; Carrot, Francine; Covès, Jacques; Gouget, Barbara

2005-01-01

Ralstonia metallidurans CH34, a soil bacterium resistant to a variety of metals, is known to reduce selenite to intracellular granules of elemental selenium (Se0). We have studied the kinetics of selenite (SeIV) and selenate (SeVI) accumulation and used X-ray absorption spectroscopy to identify the accumulated form of selenate, as well as possible chemical intermediates during the transformation of these two oxyanions. When introduced during the lag phase, the presence of selenite increased the duration of this phase, as previously observed. Selenite introduction was followed by a period of slow uptake, during which the bacteria contained Se0 and alkyl selenide in equivalent proportions. This suggests that two reactions with similar kinetics take place: an assimilatory pathway leading to alkyl selenide and a slow detoxification pathway leading to Se0. Subsequently, selenite uptake strongly increased (up to 340 mg Se per g of proteins) and Se0 was the predominant transformation product, suggesting an activation of selenite transport and reduction systems after several hours of contact. Exposure to selenate did not induce an increase in the lag phase duration, and the bacteria accumulated approximately 25-fold less Se than when exposed to selenite. SeIV was detected as a transient species in the first 12 h after selenate introduction, Se0 also occurred as a minor species, and the major accumulated form was alkyl selenide. Thus, in the present experimental conditions, selenate mostly follows an assimilatory pathway and the reduction pathway is not activated upon selenate exposure. These results show that R. metallidurans CH34 may be suitable for the remediation of selenite-, but not selenate-, contaminated environments. PMID:15870319

Techniques for loading technetium-99m and rhenium-186/188 radionuclides into pre-formed liposomes for diagnostic imaging and radionuclide therapy.

PubMed

Goins, Beth; Bao, Ande; Phillips, William T

2010-01-01

Liposomes can serve as carriers of radionuclides for diagnostic imaging and therapeutic applications. Herein, procedures are outlined for radiolabeling liposomes with the gamma-emitting radionuclide, technetium-99m ((99m)Tc), for non-invasive detection of disease and for monitoring the pharmacokinetics and biodistribution of liposomal drugs, and/or with therapeutic beta-emitting radionuclides, rhenium-186/188 ((186/188)Re), for radionuclide therapy. These efficient and practical liposome radiolabeling methods use a post-labeling mechanism to load (99m)Tc or (186/188)Re into pre-formed liposomes prepared in advance of the labeling procedure. For all liposome radiolabeling methods described, a lipophilic chelator is used to transport (99m)Tc or (186/188)Re across the lipid bilayer of the pre-formed liposomes. Once within the liposome interior, the pre-encapsulated glutathione or ammonium sulfate (pH) gradient provides for stable entrapment of the (99m)Tc and (186/188)Re within the liposomes. In the first method, (99m)Tc is transported across the lipid bilayer by the lipophilic chelator, hexamethylpropyleneamine oxime (HMPAO) and (99m)Tc-HMPAO becomes trapped by interaction with the pre-encapsulated glutathione within the liposomes. In the second method, (99m)Tc or (186/188)Re is transported across the lipid bilayer by the lipophilic chelator, N,N-bis(2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA), and (99m)Tc-BMEDA or (186/188)Re-BMEDA becomes trapped by interaction with pre-encapsulated glutathione within the liposomes. In the third method, an ammonium sulfate (pH) gradient loading technique is employed using liposomes with an extraliposomal pH of 7.4 and an interior pH of 5.1. BMEDA, which is lipophilic at pH 7.4, serves as a lipophilic chelator for (99m)Tc or (186/188)Re to transport the radionuclides across the lipid bilayer. Once within the more acidic liposome interior, (99m)Tc/(186/188)Re-BMEDA complex becomes protonated and more hydrophilic, which

Bone scanning in severe external otitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levin, W.J.; Shary, J.H. 3d.; Nichols, L.T.

1986-11-01

Technetium99 Methylene Diphosphate bone scanning has been considered an early valuable tool to diagnose necrotizing progressive malignant external otitis. However, to our knowledge, no formal studies have actually compared bone scans of otherwise young, healthy patients with severe external otitis to scans of patients with clinical presentation of malignant external otitis. Twelve patients with only severe external otitis were studied with Technetium99 Diphosphate and were compared to known cases of malignant otitis. All scans were evaluated by two neuroradiologists with no prior knowledge of the clinical status of the patients. Nine of the 12 patients had positive bone scans withmore » many scans resembling those reported with malignant external otitis. Interestingly, there was no consistent correlation between the severity of clinical presentation and the amount of Technetium uptake. These findings suggest that a positive bone scan alone should not be interpreted as indicative of malignant external otitis.« less

Photoreduction of 99Tc Pertechnetate by Nanometer-Sized Metal Oxides: New Strategies for Formation and Sequestration of Low-Valent Technetium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burton-Pye, Benjamin P.; Radivojevic, Ivana; McGregor, Donna

2011-11-23

Technetium-99 ( 99Tc)(β - max: 293.7 keV; t 1/2: 2.1 x 10 5 years) is a byproduct of uranium-235 fission and comprises a large component of radioactive waste. Under aerobic conditions and in a neutral- basic environment, the pertechnetate anion ( 99TcO 4 -) is stable. 99TcO 4 - is very soluble, migrates easily through the environment and does not sorb well onto mineral surfaces, soils or sediments. This study moves forward a new strategy for the reduction of TcO 4 - and chemical incorporation of the reduced 99Tc into a metal oxide material. This strategy employs a single material,more » a polyoxometalate (POM), α 2-[P 2W 17O 61] 10-, that can be photoactivated in the presence of 2-propanol to transfer electrons to TcO 4 - and incorporate the reduced 99Tc covalently into the α 2 - framework to form the Tc VO species, Tc VO(α 2-P 2W 17O 61) 7-. This occurs via the formation of an intermediate species that slowly converts to Tc VO(α 2-P 2W 17O 61) 7-. EXAFS and XANES analysis and preliminary EPR analysis, suggests that the intermediate consists of a Tc(IV) α 2- species where the 99Tc is likely bound to only 2 of the 4 W-O oxygen atoms in the α 2-[P 2W 17O 61] 10- defect. This intermediate then oxidizes and converts to the 99Tc VO(α 2-P 2W 17O 61) 7- product. The reduction and incorporation of 99TcO 4- was accomplished in a ''one pot'' reaction using both sunlight and UV irradiation, and monitored as a function of time using multinuclear NMR and radio TLC. The process was further probed by the ''step-wise'' generation of reduced α 2-P 2W 17O 61 12- through bulk electrolysis followed by the addition of TcO 4 -. The reduction and incorporation of ReO 4 -, as a non-radioactive surrogate for 99Tc, does not proceed through the intermediate species, and Re VO is incorporated quickly into the α 2-[P 2W 17O 61] 10- defect. These observations are consistent with the periodic trends of 99Tc and Re. Specifically, 99Tc is more easily reduced compared to Re. In addition

The Availability of Indium: The Present, Medium Term, and Long Term

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lokanc, Martin; Eggert, Roderick; Redlinger, Michael

2015-10-01

Demand for indium is likely to increase if the growth in deployment of the copper-indium-gallium-selenide (CIGS) and III-V thin-film photovoltaic technologies accelerates. There are concerns about indium supply constraints since it is relatively rare element in the earth's crust and because it is produced exclusively as a byproduct.

Corrosion Behavior of Nuclear Waste Storage Canister Materials

NASA Astrophysics Data System (ADS)

Grant, John

The nature of interaction of mild steel nuclear waste storage containers with technetium ions is not fully known. Technetium is formed during nuclear processing and some of this technetium has leaked at the Hanford nuclear waste storage site in Washington State. It is often found as highly oxidized pertechnetate (TeO4-) anions at these storage sites which also happen to be highly alkaline and contain a significant amount of nitrate. Theoretically, pertechnetate anions can act as electron acceptors and interact with the mild steel containers and accelerate the oxidation (corrosion) of steel. It is of interest to identify if pertechnetate anions pose a corrosion hazard to the mild steel nuclear waste storage tanks, under the conditions of the storage sites, as that can accelerate the degradation of the tanks and lead to further contamination. In this thesis, the interaction of two relevant container materials, namely, steel alloys A285 and A537 with a technetium surrogate, rhenium was studied. Perrhenate was used as an analog for pertechnetate. As all isotopes of technetium are radioactive, rhenium was chosen as the experimental surrogate due to its chemical similarity to technetium. Electrochemical behavior was evaluated using potentiodynamic polarization tests, and the surface morphology was studied using optical microscopy and scanning electron microscopy. Potentiodynamic polarization tests were conducted in 1.0M NaNO3 + 0.1M NaOH and 1.0M NaNO3 + 0.1M NaOH + 0.02M NaReO4. Tests were performed at three different temperatures, namely, (i) room temperature, (ii) 50°C and (iii) 80°C to study the effect of higher temperatures found in the storage sites. Corrosion current, corrosion potential, anodic and cathodic Tafel slopes, polarization resistance and corrosion rates were obtained from electrochemical testing and evaluated. Increasing temperatures was found to lead to increasing corrosion rates for all samples. The data also revealed increased corrosion from

Reduction of Pertechnetate By Acetohydroxamic Acid: Formation of [tc**II(NO)(AHA)(2)(H(2)O)]**+ And Implications for the UREX Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, C.-M.S.; Lukens, W.W.; Poineau, F.

2009-05-18

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the X-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry and the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but it may be augmented bymore » some products of the reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex ([Tc{sup II}(NO)(AHA){sub 2}H{sub 2}O]{sup +}, 1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent: potentiometric-spectrophotometric titration studies indicate a single species from pH 4 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The potential formation of 1 during reprocessing may strongly impact the fate of technetium in the nuclear fuel cycle.« less

Multifunctional 2D- Materials: Selenides and Halides

NASA Technical Reports Server (NTRS)

Singh, N. B.; Su, Ching Hua; Arnold, Brad; Choa, Fow-Sen; Bohorfous, Sara

2016-01-01

Material is the key component and controls the performance of the detectors, devices and sensors. The materials design, processing, growth and fabrication of bulk and nanocrystals and fabrication into devices and sensors involve multidisciplinary team of experts. This places a large burden on the cost of the novel materials development. Due to this reason there is a big thrust for the prediction of multifunctionality of materials before design and development. Up to some extent design can achieve certain properties. In multinary materials processing is also a big factor. In this presentation, examples of two classes of industrially important materials will be described.

Structure of selenium incorporated in pyrite and mackinawite as determined by XAFS analyses

NASA Astrophysics Data System (ADS)

Diener, A.; Neumann, T.; Kramar, U.; Schild, D.

2012-05-01

Selenium has a toxic potential leading to diseases by ingestion and a radiotoxic potential as 79Se radionuclide if discharged from a high-level nuclear waste repository in deep geological formations into the biosphere. Selenium is often associated with sulfides, such as pyrite, the most important near-surface iron sulfide and constituent of host rocks and bentonite backfills considered for radioactive waste disposal. This study was aimed at investigating the incorporation of Se2- and Se4+ into pyrite and mackinawite to determine the relevance of iron sulfides to Se retention and the type of structural bonding. The syntheses of pyrite and mackinawite occurred via direct precipitation in batches and also produced coatings on natural pyrite in mixed-flow reactor experiments (MFR) under anoxic conditions at Se concentrations in the solutions of up to 10- 3 mol/L. Mineralogical analyses by SEM and XRD reveal the formation of pyrite and mackinawite phases. The average Se2- uptake in pyrite in batch experiments amounts to 98.6%. In MFR syntheses, it reaches 99.5%, both suggesting a high potential for retention. XAFS results indicate a substitution of sulfur by selenide during instantaneous precipitation in highly supersaturated solutions only. In selenide-doted mackinawite S2- was substituted by Se2-, resulting in a mackinawite-type compound. S- is substituted by Se- in selenide-doted pyrite, yielding a FeSSe compound as a slightly distorted pyrite structure. Under slighter supersaturated conditions, XAFS results indicate an incorporation of Se2- and Se4+ predominantly as Se0. This study shows that a substitution of S by Se in iron sulfides is probable only for highly supersaturated solutions under acidic and anoxic conditions. Under closer equilibrium conditions, Se0 is expected to be the most stable species.

Phase relations in KxFe2-ySe2 and the structure of superconducting KxFe2Se2 via high-resolution synchrotron diffraction

NASA Astrophysics Data System (ADS)

Shoemaker, Daniel P.; Chung, Duck Young; Claus, Helmut; Francisco, Melanie C.; Avci, Sevda; Llobet, Anna; Kanatzidis, Mercouri G.

2012-11-01

Superconductivity in iron selenides has experienced a rapid growth, but not without major inconsistencies in the reported properties. For alkali-intercalated iron selenides, even the structure of the superconducting phase is a subject of debate, in part because the onset of superconductivity is affected much more delicately by stoichiometry and preparation than in cuprate or pnictide superconductors. If high-quality, pure, superconducting intercalated iron selenides are ever to be made, the intertwined physics and chemistry must be explained by systematic studies of how these materials form and by and identifying the many coexisting phases. To that end, we prepared pure K2Fe4Se5 powder and superconductors in the KxFe2-ySe2 system, and examined differences in their structures by high-resolution synchrotron and single-crystal x-ray diffraction. We found four distinct phases: semiconducting K2Fe4Se5, a metallic superconducting phase KxFe2Se2 with x ranging from 0.38 to 0.58, the phase KFe1.6Se2 with full K occupancy and no Fe vacancy ordering, and a oxidized phase K0.51(5)Fe0.70(2)Se that forms the PbClF structure upon exposure to moisture. We find that the vacancy-ordered phase K2Fe4Se5 does not become superconducting by doping, but the distinct iron-rich minority phase KxFe2Se2 precipitates from single crystals upon cooling from above the vacancy ordering temperature. This coexistence of separate metallic and semiconducting phases explains a broad maximum in resistivity around 100 K. Further studies to understand the solubility of excess Fe in the KxFe2-ySe2 structure will shed light on the maximum fraction of superconducting KxFe2Se2 that can be obtained by solid state synthesis.

Evidence of β-antimonene at the Sb/Bi2Se3 interface.

PubMed

Flammini, R; Colonna, S; Hogan, C; Mahatha, S K; Papagno, M; Barla, A; Sheverdyaeva, P M; Moras, P; Aliev, Z S; Babanly, M B; Chulkov, E V; Carbone, C; Ronci, F

2018-01-10

We report a study of the interface between antimony and the prototypical topological insulator Bi 2 Se 3 . Scanning tunnelling microscopy measurements show the presence of ordered domains displaying a perfect lattice match with bismuth selenide. Density functional theory calculations of the most stable atomic configurations demonstrate that the ordered domains can be attributed to stacks of β-antimonene.

Evidence of β-antimonene at the Sb/Bi2Se3 interface

NASA Astrophysics Data System (ADS)

Flammini, R.; Colonna, S.; Hogan, C.; Mahatha, S. K.; Papagno, M.; Barla, A.; Sheverdyaeva, P. M.; Moras, P.; Aliev, Z. S.; Babanly, M. B.; Chulkov, E. V.; Carbone, C.; Ronci, F.

2018-02-01

We report a study of the interface between antimony and the prototypical topological insulator Bi2Se3. Scanning tunnelling microscopy measurements show the presence of ordered domains displaying a perfect lattice match with bismuth selenide. Density functional theory calculations of the most stable atomic configurations demonstrate that the ordered domains can be attributed to stacks of β-antimonene.

Thin film solar cell configuration and fabrication method

DOEpatents

Menezes, Shalini

2009-07-14

A new photovoltaic device configuration based on an n-copper indium selenide absorber and a p-type window is disclosed. A fabrication method to produce this device on flexible or rigid substrates is described that reduces the number of cell components, avoids hazardous materials, simplifies the process steps and hence the costs for high volume solar cell manufacturing.

Reactor shutdown delays medical procedures

NASA Astrophysics Data System (ADS)

Gwynne, Peter

2008-01-01

A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

REPORT FOR COMMERCIAL GRADE NICKEL CHARACTERIZATION AND BENCHMARKING

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2012-12-20

Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, has completed the collection, sample analysis, and review of analytical results to benchmark the concentrations of gross alpha-emitting radionuclides, gross beta-emitting radionuclides, and technetium-99 in commercial grade nickel. This report presents methods, change management, observations, and statistical analysis of materials procured from sellers representing nine countries on four continents. The data suggest there is a low probability of detecting alpha- and beta-emitting radionuclides in commercial nickel. Technetium-99 was not detected in any samples, thus suggesting it is not present in commercial nickel.

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, V.W.; Caldarone, A.G.; Falk, R.H.

1983-07-01

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidois. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of tc PYP scannning as a screening test for soft-tissue amyloidosis is discussed.

Direct comparison of solid-phase gastric emptying times assessed by means of a carbon isotope-labeled sodium acetate breath test and technetium Tc 99m albumin colloid radioscintigraphy in healthy cats.

PubMed

Schmitz, Silke; Götte, Birte; Borsch, Christian; Kunz, Clemens; Failing, Klaus; Neiger, Reto

2014-07-01

To directly compare solid-phase gastric emptying times assessed by means of a [(13)C]sodium acetate breath test ([(13)C]-SABT) and technetium Tc 99m albumin colloid radioscintigraphy ((99m)Tc-ACR) in healthy cats. 12 healthy cats. After ingestion of a test meal containing 50 mg of [(13)C]sodium acetate and 250 MBq of (99m)Tc-albumin colloid, each cat underwent simultaneous [(13)C]-SABT and (99m)Tc-ACR on 2 consecutive days. Breath samples and scintigrams were acquired at 30, 60, 90, 120, 150, 180, 210, 240, 300, 360, 480, and 600 minutes after meal ingestion. Quartiles of gastric emptying (25%, 50%, and 75%) were calculated for breath test analysis by use of the area under the curve of the (13)C:(12)C ratio. Quartiles of gastric emptying times were extrapolated from the scintigraphic findings by beans of nonlinear curve regression analysis. Mean ± SD gastric half-emptying (50%) times obtained with [(13)C]-SABT and (99m)Tc-ACR, were 239 ± 28 minutes and 276 ± 59 minutes, respectively. A 2-way repeated-measures ANOVA revealed that mean gastric emptying times determined with [(13)C]-SABT and (99m)Tc-ACR differed significantly. For the stages of gastric emptying, Pearson correlation between the 2 methods was good at 25% (r = 0.655) and weak at 50% (r = 0.588) and 75% (r = 0.566)of gastric emptying. Results indicated that the [(13)C]-SABT can be a valid alternative to (99m)Tc-ACR in healthy cats; it was easy to perform, was tolerated well by the cats, and had acceptable correlation to scintigraphic findings at gastric emptying of 25%, 50% and 75%. Studies in cats with delayed gastric emptying will be needed to verify the validity of the [(13)C]-SABT.

Characterization of Raw and Decopperized Anode Slimes from a Chilean Refinery

NASA Astrophysics Data System (ADS)

Melo Aguilera, Evelyn; Hernández Vera, María Cecilia; Viñals, Joan; Graber Seguel, Teófilo

2016-04-01

This work characterizes raw and decopperized slimes, with the objective of identifying the phases in these two sub-products. The main phases in copper anodes are metallic copper, including CuO, which are present in free form or associated with the presence of copper selenide or tellurides (Cu2(Se,Te)) and several Cu-Pb-Sb-As-Bi oxides. During electrorefining, the impurities in the anode release and are not deposited in the cathode, part of them dissolving and concentrated in the electrolyte, and others form a raw anode slime that contains Au, Ag, Cu, As, Se, Te and PGM, depending on the composition of the anode. There are several recovery processes, most of which involve acid leaching in the first step to dissolve copper, whose product is decopperized anode slime. SEM analysis revealed that the mineralogical species present in the raw anode slime under study were mainly eucarite (CuAgSe), naumannite (Ag2Se), antimony arsenate (SbAsO4), and lead sulfate (PbSO4). In the case of decopperized slime, the particles were mainly composed of SbAsO4 (crystalline appearance), non-stoichiometric silver selenide (Ag(2- x)Se), and chlorargyrite (AgCl).

Real-Space Mapping of Surface Trap States in CIGSe Nanocrystals Using 4D Electron Microscopy.

PubMed

Bose, Riya; Bera, Ashok; Parida, Manas R; Adhikari, Aniruddha; Shaheen, Basamat S; Alarousu, Erkki; Sun, Jingya; Wu, Tom; Bakr, Osman M; Mohammed, Omar F

2016-07-13

Surface trap states in copper indium gallium selenide semiconductor nanocrystals (NCs), which serve as undesirable channels for nonradiative carrier recombination, remain a great challenge impeding the development of solar and optoelectronics devices based on these NCs. In order to design efficient passivation techniques to minimize these trap states, a precise knowledge about the charge carrier dynamics on the NCs surface is essential. However, selective mapping of surface traps requires capabilities beyond the reach of conventional laser spectroscopy and static electron microscopy; it can only be accessed by using a one-of-a-kind, second-generation four-dimensional scanning ultrafast electron microscope (4D S-UEM) with subpicosecond temporal and nanometer spatial resolutions. Here, we precisely map the collective surface charge carrier dynamics of copper indium gallium selenide NCs as a function of the surface trap states before and after surface passivation in real space and time using S-UEM. The time-resolved snapshots clearly demonstrate that the density of the trap states is significantly reduced after zinc sulfide (ZnS) shelling. Furthermore, the removal of trap states and elongation of carrier lifetime are confirmed by the increased photocurrent of the self-biased photodetector fabricated using the shelled NCs.

The role of interparticle heterogeneities in the selenization pathway of Cu-Zn-Sn-S nanoparticle thin films: A real-time study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, Nathaniel J.; Mainz, Roland; Walker, Bryce C.

2015-06-10

Real-time energy dispersive x-ray diffraction (EDXRD) analysis has been utilized to observe the selenization of Cu-Zn-Sn-S nanoparticle films coated from three nanoparticle populations: Cu- and Sn-rich particles roughly 5 nm in size, Zn-rich nanoparticles ranging from 10 to 20 nm in diameter, and a mixture of both types of nanoparticles (roughly 1:1 by mass), which corresponds to a synthesis recipe yielding CZTSSe solar cells with reported total-area efficiencies as high as 7.9%. The EDXRD studies presented herein show that the formation of copper selenide intermediates during the selenization of mixed-particle films can be primarily attributed to the small, Cu- andmore » Sn-rich particles. Moreover, the formation of these copper selenide phases represents the first stage of the CZTSSe grain growth mechanism. The large, Zn-rich particles subsequently contribute their composition to form micrometer-sized CZTSSe grains. In conclusion, these findings enable further development of a previously proposed selenization pathway to account for the roles of interparticle heterogeneities, which in turn provides a valuable guide for future optimization of processes to synthesize high quality CZTSSe absorber layers.« less

Creatine kinase MB isoenzyme in dermatomyositis: a noncardiac source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larca, L.J.; Coppola, J.T.; Honig, S.

1981-03-01

Three patients with polymyositis had elevated serum levels of creatine kinase MB isoenzyme. The presence of this isoenzyme is used extensively to diagnose myocardial infarction, but the isoenzyme is also found in sera of patients with primary muscular and neuromuscular disorders. Researchers studied cardiac function in two of our patients with electrocardiograms, technetium stannous pyrophosphate scanning, and technetium 99m-labeled erythrocyte gated blood pool imaging and in the third patient by postmortem examination. There was no evidence of myocardial involvement to account for the high serum levels of isoenzyme. Creatine kinase MB in the sera of patients with polymyositis does notmore » necessarily indicate myocardial necrosis.« less

Performance enhancement of hybrid solar cells through chemical vapor annealing.

PubMed

Wu, Yue; Zhang, Genqiang

2010-05-12

Improvement in power conversion efficiency has been observed in cadmium selenide nanorods/poly(3-hexylthiophene) hybrid solar cells through benzene-1,3-dithiol chemical vapor annealing. Phosphor NMR studies of the nanorods and TEM/AFM characterizations of the morphology of the blended film showed that the ligand exchange reaction and related phase separation happening during the chemical vapor annealing are responsible for the performance enhancement.

Investigation of the thermophysical properties of high-melting materials with the aid of a complex of instruments

NASA Technical Reports Server (NTRS)

Bolgar, A. S.; Gordiyenko, S. P.; Guseva, Y. A.; Turchanin, A. G.; Fenochka, B. V.; Fesenko, V. V.

1984-01-01

The evaporation rate, vapor pressure, heats of evaporation reaction (sublimation, dissociation), enthalpy, electrical resistance, heat capacity, emissivity, and heat conductivity of various carbides, borides, sulfides, nitrides, selenides, and phosphides were investigated. A set of high temperature high vacuum devices, calorimeters (designed for operation at 400 to 1300 K and from 1200 K), and mass spectrometers, most of which were specially developed for these studies, is described.

Redistribution of elements between wastes and organic-bearing material in the dispersion train of gold-bearing sulfide tailings: Part I. Geochemistry and mineralogy.

PubMed

Saryg-Ool, B Yu; Myagkaya, I N; Kirichenko, I S; Gustaytis, M A; Shuvaeva, O V; Zhmodik, S M; Lazareva, E V

2017-03-01

Migration and redistribution of elements during prolonged interaction of cyanide wastes with the underlying natural organic-bearing material have been studied in two ~40cm deep cores that sample primary ores and their weathering profile (wastes I and II, respectively) in the dispersion train of gold-bearing sulfide tailings in Siberia. Analytical results of SR-XRF, whole-rock XRF, AAS, CHNS, and SEM measurements of core samples show high K, Sr, Ti, and Fe enrichments and correlation of P 2 O 5 and Mn with LOI and C org . Organic material interlayered or mixed with the wastes accumulates Cu, Zn, Se, Cd, Ag, Au, and Hg. The peat that contacts wastes II bears up to 3wt.% Zn, 1000g/t Se, 100g/t Cd, and 8000g/t Hg. New phases of Zn and Hg sulfides and Hg selenides occur as abundant sheaths over bacterial cells suggesting microbial mediation in sorption of elements. Organic-bearing material in the cores contains 10-30g/t Au in 2-5cm thick intervals, both within and outside the intervals rich in sulfides and selenides. Most of gold is invisible but reaches 345g/t and forms 50nm to 1.5μm Au 0 particles in a thin 2-3cm interval of organic remnants mixed with wastes I. Vertical and lateral infiltration of AMD waters in peat and oxidative dissolution of wastes within the dispersion train of the Ursk tailings lead to redistribution of elements and their accumulation by combined physical (material's permeability, direction AMD), chemical (complexing, sorption by organic matter and Fe(III) hydroxides) and biochemical (metabolism of sulfate-reducing bacteria) processes. The accumulated elements form secondary sulfates, and Hg and Zn selenides. The results provide insights into accumulation of elements in the early history of coal and black shale deposits and have implications for remediation of polluted areas and for secondary enrichment technologies. Copyright © 2017 Elsevier B.V. All rights reserved.

Polarization-Induced Interfacial Reactions between Nickel and Selenium in Ni/Zirconia SOFC Anodes and Comparison with Sulfur Poisoning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.

2011-01-10

Three distinctly different characteristic responses of a nickel/yttria-stabilized zirconia (Ni/YSZ) cermet anode to the presence of hydrogen selenide in synthetic coal gas were observed, depending on temperature (650-800oC), H2Se concentration (0-40 ppm), and especially on the extent of anodic polarization (0 to ~0.5 V). The first level of response was characterized by a rapid but modest decrease in power density to a new steady state, with no further degradation observed in tests up to 700 hours in duration. Mostly observed at high temperatures, low H2Se concentrations, and low anodic polarizations, this response level was similar to effects caused by themore » presence of H2S, but with slower onset and lower reversibility. Higher anodic polarization at a constant current could trigger a second level of response characterized by oscillatory behavior involving cycles of rapid performance loss followed by rapid recovery. Oscillations at the constant current density were accompanied by the appearance and disappearance of a new feature in the electrochemical impedance spectrum with a summit frequency of ~100 Hz. Oscillatory behavior ceased when the current density was lowered. Such behavior was not observed for cells operated at a constant potential of similar magnitude, though. A third level of response, irreversible cell failure, could be induced by further increases in anodic polarization, additionally favored by low temperature and high H2Se concentration. Post-test analyses of failed cells by electron microscopy revealed the extensive microstructural changes including the appearance of nickel oxide and nickel selenide alteration phases, only at the anode/electrolyte interface. From bulk thermochemical considerations the formation of nickel selenides could not be expected. Local chemical conditions created at the anode/electrolyte interface appear to be of overriding importance with respect to the extent of Ni/YSZ anode interactions with H2Se in coal gas.« less

Thermoelectric materials ternary penta telluride and selenide compounds

DOEpatents

Sharp, Jeffrey W.

2001-01-01

Ternary tellurium compounds and ternary selenium compounds may be used in fabricating thermoelectric devices with a thermoelectric figure of merit (ZT) of 1.5 or greater. Examples of such compounds include Tl.sub.2 SnTe.sub.5, Tl.sub.2 GeTe.sub.5, K.sub.2 SnTe.sub.5 and Rb.sub.2 SnTe.sub.5. These compounds have similar types of crystal lattice structures which include a first substructure with a (Sn, Ge) Te.sub.5 composition and a second substructure with chains of selected cation atoms. The second substructure includes selected cation atoms which interact with selected anion atoms to maintain a desired separation between the chains of the first substructure. The cation atoms which maintain the desired separation between the chains occupy relatively large electropositive sites in the resulting crystal lattice structure which results in a relatively low value for the lattice component of thermal conductivity (.kappa..sub.g). The first substructure of anion chains indicates significant anisotropy in the thermoelectric characteristics of the resulting semiconductor materials.

Thermoelectric materials: ternary penta telluride and selenide compounds

DOEpatents

Sharp, Jeffrey W.

2002-06-04

Ternary tellurium compounds and ternary selenium compounds may be used in fabricating thermoelectric devices with a thermoelectric figure of merit (ZT) of 1.5 or greater. Examples of such compounds include Tl.sub.2 SnTe.sub.5, Tl.sub.2 GeTe.sub.5, K.sub.2 SnTe.sub.5 and Rb.sub.2 SnTe.sub.5. These compounds have similar types of crystal lattice structures which include a first substructure with a (Sn, Ge) Te.sub.5 composition and a second substructure with chains of selected cation atoms. The second substructure includes selected cation atoms which interact with selected anion atoms to maintain a desired separation between the chains of the first substructure. The cation atoms which maintain the desired separation between the chains occupy relatively large electropositive sites in the resulting crystal lattice structure which results in a relatively low value for the lattice component of thermal conductivity (.kappa..sub.g). The first substructure of anion chains indicates significant anisotropy in the thermoelectric characteristics of the resulting semiconductor materials.

Ion beam modification of topological insulator bismuth selenide

DOE PAGES

Sharma, Peter Anand; Sharma, A. L. Lima; Hekmaty, Michelle A.; ...

2014-12-17

In this study, we demonstrate chemical doping of a topological insulator Bi 2Se 3 using ion implantation. Ion beam-induced structural damage was characterized using grazing incidence X-ray diffraction and transmission electron microscopy. Ion damage was reversed using a simple thermal annealing step. Carrier-type conversion was achieved using ion implantation followed by an activation anneal in Bi 2Se 3 thin films. These two sets of experiments establish the feasibility of ion implantation for chemical modification of Bi 2Se 3, a prototypical topological insulator. Ion implantation can, in principle, be used for any topological insulator. The direct implantation of dopants should allowmore » better control over carrier concentrations for the purposes of achieving low bulk conductivity. Ion implantation also enables the fabrication of inhomogeneously doped structures, which in turn should make possible new types of device designs.« less

Electrolytically deposited Cadmium Selenide Films for Photovoltaic Applications

NASA Astrophysics Data System (ADS)

Dervos, C. T.; Palaiologopoulou, M. D.

2012-10-01

CdSe films were electrodeposited on pure nickel substrates. The nickel substrate was polished to a mirror finish by Al2O3 paste, etched in 10% HCl solution for 40 s and rinsed thoroughly by de-ionized water. The deposition bath contained solutions with excessive Cd2+ (0.2M) from CdSO4 and small amounts of SeO2 (1x10-3 M). The pH of the bath was adjusted to a value of 2.2 at RT by adding 10% H2SO4. The bath was first thermostated at the required temperature, which varied from 55°C to 65°C. Plating was accomplished at deposition potential 1000 mV (vs. Hg/Hg2SO4). The films formed had a uniform thickness and it was found to be approximately 2.0 μm thick (for 20 min electrodeposition process. The produced CdSe films were characterized by X-Ray diffraction and SEM. The induced semiconductor doping effect by thermal annealing in pure dry nitrogen gas was also investigated. Gold contacts were placed on top of the CdSe films, either by evaporation, or mechanically. Depending on the deposition parameters the electrical characteristics of the Ni/CdSe/Au structures may exhibit rectification properties. The optical excitation of the structure was investigated for various CdSe thicknesses.

Selenide isotope generator (SIG) for the Galileo Mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-09-01

This agreement establishes the procedures and defines the responsibilities that are a part of the DOE/TES/3M interface for the duration of the SIG/Galileo Mission Program. The agreement is intended to expand upon the Interface Document which is Attachment IV to both the 3M and TES Contract Statement of Work. The agreement is effective upon approval by DOE, TES and 3M Company.

Selenidation of epitaxial silicene on ZrB2

NASA Astrophysics Data System (ADS)

Wiggers, F. B.; Yamada-Takamura, Y.; Kovalgin, A. Y.; de Jong, M. P.

2018-01-01

The deposition of elemental Se on epitaxial silicene on ZrB2 thin films was investigated with synchrotron-based core-level photoelectron spectroscopy and low-energy electron diffraction. The deposition of Se at room temperature caused the appearance of Si 2p peaks with chemical shifts of n × 0.51 ± 0.04 eV (n = 1-4), suggesting the formation of SiSe2. This shows that capping the silicene monolayer, without affecting its structural and electronic properties, is not possible with Se. The annealing treatments that followed caused the desorption of Se and Si, resulting in the etching of the Si atoms formerly part of the silicene layer, and the formation of bare ZrB2(0001) surface area. In addition, a ZrB2(0001)-(√7 × 3)R40.9° surface reconstruction was observed, attributed to a Se-termination of the surface of the transition metal diboride thin film.

Versatile Chromium-Doped Zinc Selenide Infrared Laser Sources

DTIC Science & Technology

2010-05-01

ability of the fixed- angle curved mirrors in the Z- cavity to compensate for the increasing astigmatism from the Brewster - angle thermal lens in the...duty cycle at varying PRFs. 20 Table 4: Thermal Lensing Power at 1 kHz PRF, 1 W peak power, Q-switched Laser PRF (kHz) Thermal lens power (m-1...with it some negative astigmatism effects which are compounded by thermal lensing in the crystal which is now at an angle . To counteract this

Morphology control of layer-structured gallium selenide nanowires.

PubMed

Peng, Hailin; Meister, Stefan; Chan, Candace K; Zhang, Xiao Feng; Cui, Yi

2007-01-01

Layer-structured group III chalcogenides have highly anisotropic properties and are attractive materials for stable photocathodes and battery electrodes. We report the controlled synthesis and characterization of layer-structured GaSe nanowires via a catalyst-assisted vapor-liquid-solid (VLS) growth mechanism during GaSe powder evaporation. GaSe nanowires consist of Se-Ga-Ga-Se layers stacked together via van der Waals interactions to form belt-shaped nanowires with a growth direction along the [11-20], width along the [1-100], and height along the [0001] direction. Nanobelts exhibit a variety of morphologies including straight, zigzag, and saw-tooth shapes. These morphologies are realized by controlling the growth temperature and time so that the actual catalysts have a chemical composition of Au, Au-Ga alloy, or Ga. The participation of Ga in the VLS catalyst is important for achieving different morphologies of GaSe. In addition, GaSe nanotubes are also prepared by a slow growth process.

Iron-Doped Zinc Selenide: Spectroscopy and Laser Development

DTIC Science & Technology

2014-03-27

guidance, Dr. Ken Schepler for many hours of discussion about transition- metal lasers, and Dr. Patrick Berry for direct, hands-on support of this work...lifetime of this material to approach 105 µs near 100 K. This measurement is consistent with De- loach [51] and Jeĺınková [52] (see Figure 22...However, Myoung et al. have reported maximum values of no more than 65 µs at the same temperature [21]. Adams, De- loach , and Jeĺınková measured the

Handbook of Phase Transition Sulfides, Selenides and Tellurides,

DTIC Science & Technology

1984-07-01

guidance and control. The Contracting Officer is Mrs. S. Williams, DESC, Dayton, Ohio. The Contracting Officers Technical Representative is Mr. H . C...higher temperature phase change where AgGaS2 becomes metallic. REFERENCES (AgGaS2 ) 1. H . Hahn, et.al., Z. Anorg. Chem., 271, 153 (1953). 2. M.V. Hobden...Phys. Soc. Japan, Vol. 23, 37 (1967). 10. H.H. Dorner, H.P. Geserich, and H . Rickert, Phys. Stat. Sol. (a), Vol. 37, K85 (1970). 11. P. Bruesch and J

Images of liposarcoma using technetium-99m bleomycin and technetium (V)-99m DMSA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohta, H.; Shane, F.I.; Endo, K.

1986-12-01

The effectiveness of Tc-99m bleomycin (BLM) and Tc(V)-99m DMSA are compared with that of Ga-67 citrate, which is currently the most widely used agent. In four patients with lipomatous tumors, the clinical significance of tumor imaging with each of these three agents is discussed and compared. Results indicate that both Tc-99m BLM and Tc(V)-99m DMSA are superior in detecting the extension or localization of liposarcomas.

Cost Benefit Analysis of Integrated COTS Energy- Related Technologies for Army’s Force Provider Module

DTIC Science & Technology

2009-09-01

Year Defense Plan (FYDP), on which the Department of Defense operates, subsequently needs 26 Richard G. Lugar, U.S. Senator for Indiana , “U.S...mature thin-film technologies exist such as Amorphous Silicon (a-Si), Cadmium Telluride (CdTe), and Copper Indium Gallium (di) Selenide (CIGS), all...cheaper processing, lower material costs, and is free of the environmental and health hazard issues of cadmium . Amorphous silicon coupled with

Composite-Nanoparticles Thermal History Sensors

DTIC Science & Technology

2014-05-01

Nanostructures Under Different Hydrothermal Synthesis Conditions Fig. 5. SEM image of PbTe solid nano- and micro-cubes obtained at 100 !C (a) and 160 !C (b...Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of PbSe microflowers, a similar pro- cedure was followed with NaTeO3...Telluride and Selenide Nanostructures Under Different Hydrothermal Synthesis Conditions For the preparation of PbSe microflowers, a similar pro- cedure

Application of Copper Indium Gallium Diselenide Photovoltaic Cells to Extend the Endurance and Capabilities of Unmanned Aerial Vehicles

DTIC Science & Technology

2009-09-01

Group V element to make them n or p material. Another common group of semiconductors are called III–V compounds , such as gallium arsenide (GaAs), or...these compounds used for photovoltaics are Cadmium Telluride (CdTe), and Copper Indium Gallium DiSelenide, commonly referred to as CIGS [49]. Figure...INDIUM GALLIUM DISELENIDE PHOTOVOLTAIC CELLS TO EXTEND THE ENDURANCE AND CAPABILITIES OF UNMANNED AERIAL VEHICLES by William R. Hurd

Worldwide Emerging Environmental Issues Affecting the U.S. Military. May 2006

DTIC Science & Technology

2006-05-01

include lead, mercury , cadmium and several other substances. [See Recycling Regulations in the EU in August 2005 and Two E-waste laws entered into... mercury and cadmium portable batteries may contain (Certain classes, such as those for emergency systems and handheld tools, are excepted.) The new...multiple-exciton generation in other semiconductors, including lead sulphide , lead telluride and cadmium selenide. What’s more, Klimov says his group

Retrograde spread of 5-aminosalicylic acid enemas in patients with active ulcerative colitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campieri, M.; Lanfranchi, G.A.; Brignola, C.

1986-02-01

In an attempt to know the exact retrograde spread of high-dosage 5-aminosalicylic acid enemas, we have studied eight patients with active left-sided colitis, by adding a small amount of barium sulfate to the enemas and by checking the spread radiologically after 15 minutes, 1 hour, and 6 hours. Four grams of 5-aminosalicylic acid in 100-ml enemas and 4 gm in 200-ml enemas were used. The same experiment was repeated in a subsequent attack, with enemas labeled with technetium-99m and checked by scintiscans in five of these patients. We always have observed a volume-dependent spread of enemas but, interestingly, in themore » patients studied with technetium-99m there was always a wider spread than that which was detected with barium enemas. In all five patients, 100-ml enemas reached the splenic flexure. In two patients with total colitis, a progression of 100-ml technetium-99m enemas was performed in the transverse colon, but the maximum opacity remained in the left side. We can conclude that 4 gm of 5-aminosalicylic acid in 100-ml enemas can be suitable for treating patients with left-sided colitis, and will represent a valid addition for patients with more extensive colitis.« less

A secular technetium-molybdenum generator

NASA Astrophysics Data System (ADS)

Araujo, Wagner L.; Campos, Tarcisio P. R.

2015-05-01

A compact secular molybdenium generator is subject of this paper. This generator represents a nuclear system that comprises a hydrogen-isotopes fusor, moderator, reflector and shield. Deuterium fusion reactions in a tritiated or deuterated target provide the neutron source. A moderation fluid slowdown the neutron energy which increases 98Mo(n,γ)99Mo capture reaction rates. Neutron reflection minimizes the neutron escape and the radiation shield encloses the device. The neutron yield calculation along with electromagnetic and nuclear simulations were addressed. Results revealed the accelerator equipotential surfaces ranging from -30 to 150 kV, the ion trajectories and the energy beam profile define a deuteron current of 1 A with energy of 180 keV at the target, the spatial distribution of the neutron flux, and the 99Mo and 99mTc activities in function of transmuter operation time. The kinetics of the 99mTc correlated to its precursor activity demonstrates a secular equilibrium providing 2 Ci in a operational time of 150 h. As conclusion, the investigated nuclear and electromagnetic features have demonstrated that such generator shall have a notable potential for feeding the 99mTc clinical application.

Technetium-99m generator system

DOEpatents

Mirzadeh, Saed; Knapp, Jr., Furn F.; Collins, Emory D.

1998-01-01

A .sup.99 Mo/.sup.99m Tc generator system includes a sorbent column loaded with a composition containing .sup.99 Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating .sup.99m Tc eluted from the sorbent column. A method of preparing a concentrated solution of .sup.99m Tc includes the general steps of: a. providing a sorbent column loaded with a composition containing .sup.99 Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; b. eluting the sorbent column with a salt solution to elute .sup.99m Tc from the sorbent and to trap and concentrate the eluted .sup.99m Tc on the ion-exchange column; and c. eluting the concentrated .sup.99m Tc from the ion-exchange column with a solution comprising a reductive complexing agent.

Technetium-99m generator system

DOEpatents

Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

1998-06-30

A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

Growth Mechanism of Nanowires: Ternary Chalcogenides

NASA Technical Reports Server (NTRS)

Singh, N. B.; Coriell, S. R.; Hopkins, R. H.; Su, Ching Hua; Arnold, B.; Choa, Fow-Sen; Cullum, Brian

2016-01-01

In the past two decades there has been a large rise in the investment and expectations for nanotechnology use. Almost every area of research has projected improvements in sensors, or even a promise for the emergence of some novel device technologies. For these applications major focuses of research are in the areas of nanoparticles and graphene. Although there are some near term applications with nanowires in photodetectors and other low light detectors, there are few papers on the growth mechanism and fabrication of nanowire-based devices. Semiconductor nanowires exhibit very favorable and promising optical properties, including high transparency and a several order of magnitude better photocurrent than thin film and bulk materials. We present here an overview of the mechanism of nanowire growth from the melt, and some preliminary results for the thallium arsenic selenide material system. Thallium arsenic selenide (TAS) is a multifunctional material combining excellent acousto-optical, nonlinear and radiation detection properties. We observed that small units of (TAS) nanocubes arrange and rearrange at moderate melt undercooling to form the building block of a nanowire. In some cases very long wires (less than mm) are formed. Since we avoided the catalyst, we observed self-nucleation and uncontrolled growth of wires from different places.

Prospects and performance limitations for Cu-Zn-Sn-S-Se photovoltaic technology.

PubMed

Mitzi, David B; Gunawan, Oki; Todorov, Teodor K; Barkhouse, D Aaron R

2013-08-13

While cadmium telluride and copper-indium-gallium-sulfide-selenide (CIGSSe) solar cells have either already surpassed (for CdTe) or reached (for CIGSSe) the 1 GW yr⁻¹ production level, highlighting the promise of these rapidly growing thin-film technologies, reliance on the heavy metal cadmium and scarce elements indium and tellurium has prompted concern about scalability towards the terawatt level. Despite recent advances in structurally related copper-zinc-tin-sulfide-selenide (CZTSSe) absorbers, in which indium from CIGSSe is replaced with more plentiful and lower cost zinc and tin, there is still a sizeable performance gap between the kesterite CZTSSe and the more mature CdTe and CIGSSe technologies. This review will discuss recent progress in the CZTSSe field, especially focusing on a direct comparison with analogous higher performing CIGSSe to probe the performance bottlenecks in Earth-abundant kesterite devices. Key limitations in the current generation of CZTSSe devices include a shortfall in open circuit voltage relative to the absorber band gap and secondarily a high series resistance, which contributes to a lower device fill factor. Understanding and addressing these performance issues should yield closer performance parity between CZTSSe and CdTe/CIGSSe absorbers and hopefully facilitate a successful launch of commercialization for the kesterite-based technology.

Stripes developed at the strong limit of nematicity in FeSe film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wei; Zhang, Yan; Deng, Peng

A single monolayer of iron selenide grown on strontium titanate shows an impressive enhancement of superconductivity compared with the bulk, as well as a novel Fermi surface topology, extreme two-dimensionality, and the possibility of phonon-enhanced electron pairing. For films thicker than one unit cell, however, the electronic structure is markedly different, with a drastically suppressed superconductivity and strong nematicity appearing. The physics driving this extraordinary dichotomy of superconducting behaviour is far from clear. In this paper, we use low-temperature scanning tunnelling microscopy to study multilayers of iron selenide grown by molecular beam epitaxy, and find a stripe-type charge ordering instabilitymore » that develops beneath the nematic state. The charge ordering is visible and pinned in the vicinity of impurities. And as it emerges in the strong limit of nematicity, it suggests that a magnetic fluctuation with a rather small wavevector may be competing with the ordinary collinear antiferromagnetic ordering in multilayer films. Finally, the existence of stripes in iron-based superconductors, which resemble the stripe order in cuprates, not only suggests that electronic anisotropy and correlation are playing an important role, but also provides a platform for probing the complex interactions between nematicity, charge ordering, magnetism and superconductivity in high-temperature superconductors.« less

Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe.

PubMed

Lu, X F; Wang, N Z; Wu, H; Wu, Y P; Zhao, D; Zeng, X Z; Luo, X G; Wu, T; Bao, W; Zhang, G H; Huang, F Q; Huang, Q Z; Chen, X H

2015-03-01

Iron selenide superconductors exhibit a number of unique characteristics that are helpful for understanding the mechanism of superconductivity in high-Tc iron-based superconductors more generally. However, in the case of AxFe2Se2 (A = K, Rb, Cs), the presence of an intergrown antiferromagnetic insulating phase makes the study of the underlying physics problematic. Moreover, FeSe-based systems intercalated with alkali metal ions, NH3 molecules or organic molecules are extremely sensitive to air, which prevents the further investigation of their physical properties. It is therefore desirable to find a stable and easily accessible FeSe-based superconductor to study its physical properties in detail. Here, we report the synthesis of an air-stable material, (Li0.8Fe0.2)OHFeSe, which remains superconducting at temperatures up to ~40 K, by means of a novel hydrothermal method. The crystal structure is unambiguously determined by a combination of X-ray and neutron powder diffraction and nuclear magnetic resonance. Moreover, antiferromagnetic order is shown to coexist with superconductivity. This synthetic route opens a path for exploring superconductivity in other related systems, and confirms the appeal of iron selenides as a platform for understanding superconductivity in iron pnictides more broadly.

Detection of rare species of volatile organic selenium metabolites in male golden hamster urine.

PubMed

Kwak, Jae; Ohrnberger, Sarah A; Valencak, Teresa G

2016-07-01

Selenium has been considered as an essential trace element in mammals and its intake comes mainly from food. Mammals can metabolize both inorganic and organic species, and urinary excretion is the primary elimination route of selenium. Selenosugars and trimethylselenonium ion have been identified as major urinary metabolites. Other metabolites have been reported, but they were detected in some studies and not in others. Still, a large portion of the ingested selenium eliminated from the body is unknown. Volatile selenium species may account for a certain portion of the unknown species since they can easily be lost during sample analyses. While we analyzed male golden hamster urine in search of potential volatile pheromone(s), four volatile selenium compounds were detected. They were dimethyl selenenylsulfide, dimethyl diselenide, dimethyl bis(thio)selenide, and dimethyl selenodisulfide. When the urine samples were aged and dried for 48 h, dimethyl selenodisulfide tended to increase, while others decreased. The increase might be due to the formation of dimethyl selenodisulfide via reaction of dimethyl diselenide and dimethyl trisulfide whose concentration increased as urine aged. To our knowledge, dimethyl bis(thio)selenide and dimethyl selenodisulfide have never been demonstrated in urine. It remains to be determined whether these species are common metabolites in other animals or hamster-specific.

Yeast as a model system to study metabolic impact of selenium compounds

PubMed Central

Herrero, Enrique; Wellinger, Ralf E.

2015-01-01

Inorganic Se forms such as selenate or selenite (the two more abundant forms in nature) can be toxic in Saccharomyces cerevisiae cells, which constitute an adequate model to study such toxicity at the molecular level and the functions participating in protection against Se compounds. Those Se forms enter the yeast cell through other oxyanion transporters. Once inside the cell, inorganic Se forms may be converted into selenide through a reductive pathway that in physiological conditions involves reduced glutathione with its consequent oxidation into diglutathione and alteration of the cellular redox buffering capacity. Selenide can subsequently be converted by molecular oxygen into elemental Se, with production of superoxide anions and other reactive oxygen species. Overall, these events result in DNA damage and dose-dependent reversible or irreversible protein oxidation, although additional oxidation of other cellular macromolecules cannot be discarded. Stress-adaptation pathways are essential for efficient Se detoxification, while activation of DNA damage checkpoint and repair pathways protects against Se-mediated genotoxicity. We propose that yeast may be used to improve our knowledge on the impact of Se on metal homeostasis, the identification of Se-targets at the DNA and protein levels, and to gain more insights into the mechanism of Se-mediated apoptosis. PMID:28357286