All electrochemical fabrication of a bilayer membrane composed of nanotubular photocatalyst and palladium toward high-purity hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Hattori, Masashi [Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8580 (Japan); Noda, Kei, E-mail: nodakei@elec.keio.ac.jp [Department of Electronics and Electrical Engineering, Keio University, Hiyoshi, Yokohama 223-8522 (Japan)

2015-12-01

Graphical abstract: - Highlights: • A bilayer membrane composed of TiO{sub 2} nanotube array and palladium was fabricated. • The TiO{sub 2}/Pd bilayer membrane was prepared with an all-electrochemical process. • The membrane consists of pure Pd and anatase TiO{sub 2} nanotubes with no alloy formation. • Photocatalytic H{sub 2} production and concomitant separation were demonstrated. • High-purity H{sub 2} production rate and apparent quantum yield were evaluated. - Abstract: We developed an all-electrochemical technique for fabricating a bilayer structure of a titanium dioxide (TiO{sub 2}) nanotube array (TNA) and a palladium film (TNA/Pd membrane), which works for photocatalytic high-purity hydrogen production. Electroless plating was used for depositing the Pd film on the TNA surface prepared by anodizing a titanium foil. A 3-μm-thick TNA/Pd membrane without any pinholes in a 1.5-cm-diameter area was fabricated by transferring a 1-μm-thick TNA onto an electroless-plated 2-μm-thick Pd film with a mechanical peel-off process. This ultrathin membrane with sufficient mechanical robustness showed photocatalytic H{sub 2} production via methanol reforming under ultraviolet illumination on the TNA side, immediately followed by the purification of the generated H{sub 2} gas through the Pd layer. The hydrogen production rate and the apparent quantum yield for high-purity H{sub 2} production from methanol/water mixture with the TNA/Pd membrane were also examined. This work suggests that palladium electroless plating is more suitable and practical for preparing a well-organized TNA/Pd heterointerface than palladium sputter deposition.

High-purity germanium crystal growing

International Nuclear Information System (INIS)

Hansen, W.L.; Haller, E.E.

1982-10-01

The germanium crystals used for the fabrication of nuclear radiation detectors are required to have a purity and crystalline perfection which is unsurpassed by any other solid material. These crystals should not have a net electrically active impurity concentration greater than 10 10 cm - 3 and be essentially free of charge trapping defects. Such perfect crystals of germanium can be grown only because of the highly favorable chemical and physical properties of this element. However, ten years of laboratory scale and commercial experience has still not made the production of such crystals routine. The origin and control of many impurities and electrically active defect complexes is now fairly well understood but regular production is often interrupted for long periods due to the difficulty of achieving the required high purity or to charge trapping in detectors made from crystals seemingly grown under the required conditions. The compromises involved in the selection of zone refining and crystal grower parts and ambients is discussed and the difficulty in controlling the purity of key elements in the process is emphasized. The consequences of growing in a hydrogen ambient are discussed in detail and it is shown how complexes of neutral defects produce electrically active centers

High purity materials as targets for radioisotope production: Needs ...

Indian Academy of Sciences (India)

Unknown

lity of high purity target materials, natural or enriched, are crucial for any successful radioisotope pro- gramme. Selection ... and blockages detection in buried pipelines are rendered ..... from reputed international suppliers with analysis report.

High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

Energy Technology Data Exchange (ETDEWEB)

Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

2011-07-31

Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

Method of determination of radiochemical purity of gallium-67 citrate injection

International Nuclear Information System (INIS)

Wang Quanji

1985-01-01

A simple method is used to compare the effect of five developing agents on the radiochemical purity of neutral products of 67 GaCit and on Rsub(f) values. Two preferable developing agents are recommended as suitable for the identification of 67 GaCit injection in its production. The effect of six pH values of different developing agents on radiochemical purity, Rsub(f) and chromatogram are compared for the neutral products. The results of the experiments show that the ascending paper chromatography with 1:2:4 pyridine/ethanol/water and 85:15 methanol/water is preferable for the determination of the radiochemical purity of 67 GaCit. The other developing agents also can be used if there are not any impurities except gallium radioisotopes

Radiochemical purity of Mo and Tc solution obtained after irradiation and dissolution of Mo-100-enriched and ultra-high-purity natural Mo disks

Energy Technology Data Exchange (ETDEWEB)

Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-01

Four irradiations of ultra-high-purity natural Mo targets and one irradiation using 97.4% Mo-100-enriched material were performed. The purpose of these irradiations was to determine whether the presence of Sn stabilizer in the H₂O₂ used for the dissolution of sintered Mo disks can affect the radiochemical purity of the final K₂MoO₄ in 5M KOH solution. Results from radiochemical purity tests performed using thin-layer paper chromatography show that even 2– 3× excess of Sn-stabilized H₂O₂ typically used for dissolution of sintered Mo disks did not affect the radiochemical purity of the final product.

Multicurie, transportable, integrally shielded 123Xe → 123I generator and processing system for high-purity iodine-123 production

International Nuclear Information System (INIS)

Lagunas-Solar, M.C.; Thibeau, H.L.; Goodart, C.E.; Little, F.E.; Navarro, N.J.; Hartnett, D.E.

1985-01-01

An integrally shielded 123 Xe → 123 I generator system has been designed and tested under production conditions for its suitability as a multicurie handling device from which to produce radiopharmaceutical-quality high-purity no-carrier-added (NCA) 123 I. The 123 Xe → 123 I generator system is expected to provide an alternative to current techniques and to increase the availability and reliability of high-purity 123 I made via the 127 I(p,5n) 123 Xe → 123 I nuclear reaction. The generator system is based on the Crocker Nuclear Laboratory's continuous-flow production system which has been operating since 1974 for the multicurie production of 123 I. The generator system, which consists of an integrally shielded xenon trap and separate loading and processing apparatuses, is simple and reliable to operate, can be adapted to computerized control, and provides a safe working environment for the repeated handling of multicurie amounts of Xe-I radioactivities

Formation of natural indigo derived from woad (Isatis tinctoria L.) in relation to product purity.

Science.gov (United States)

Garcia-Macias, Paulina; John, Philip

2004-12-29

There is an increasing commercial demand for naturally sourced indigo that meets the purity standards set by the synthetic product. This study concerns the indigo made from leaves of woad (Isatis tinctoria L.), and in particular its interaction with particulate impurities arising from soil and plant materials. Also, a more reliable method using N-methyl-2-pyrrolidone has been developed for the spectrophotometric determination of indigo. In a novel application of fluorescence spectroscopy, indoxyl intermediates in indigo formation are shown to be stable for minutes. The main indigo precursor from woad can be adsorbed onto Amberlite XAD16 in conformity with a Langmuir isotherm, but indigo precursors break down on this and other resin beads to yield indigo and red compounds. Indigo made from indoxyl acetate aggregates into particles, the size distribution of which can be modified by the inclusion of a fine dispersion of calcium hydroxide. Bright field microscopy of indigo products made under defined conditions and scanning electron microscopy combined with energy-dispersive X-ray analysis reveal the relationship of indigo with particulate materials. A model illustrating the interaction of indigo with particulate contaminants is developed on the basis of the results obtained, and recommendations are made for improving the purity of natural indigo.

The method for production of high purity carrier free ortophosphoric acid labeled with isotopes Phosphorus-32 and Phosphorus-33

International Nuclear Information System (INIS)

Abdukayumov, M.N.; Abdusalyamov, A.N.; Chistyakov, P.G.; Yuldashev, B.S.

2001-01-01

Extensive application for various radioactive isotopes was found in an extremity of the 20-Th century in a science and production. Labeled compounds are used with growing effectiveness in a molecular biology, gene engineering, medicine and other areas. Phosphorus-32 and Phosphorus-33 isotopes as a different labeled compounds that are used mainly in molecular biology are produced at the Radiopreparat enterprise of the Institute of Nuclear Physics of Academy of Sciences of Uzbekistan Republic. The quality of labeled preparations is very high. The specifications for above mentioned preparations corresponds to demands most of customers in different countries. P-32 or P-33 labeled orthophosphoric acid has high radiochemical purity (more than 99 %) and specific radioactivity close to theoretical. Orthophosphoric acid prepared by the described above method has radiochemical purity about 95 % and output of the target product 99%

High purity hydrogen production system by the PSA method

Energy Technology Data Exchange (ETDEWEB)

1986-01-01

In a process developed by Nippon Steel, coke oven gas is compressed and purified of tarry matter, sulphur compounds and gum-formers by adsorption. It is then passed through a three-tower pressure-swing adsorption system to recover hydrogen whose purity can be selected in the range 99 to 99.999%. A composite adsorption agent is used.

Correlation between product purity and process parameters for the synthesis of Cu2ZnSnS4 nanoparticles using microwave irradiation

Science.gov (United States)

Ahmad, R.; Nicholson, K. S.; Nawaz, Q.; Peukert, W.; Distaso, M.

2017-07-01

Kesterites (CZT(S,Se)4) emerged as a favourable photovoltaic material, leading to solar cell efficiencies as high as 12.7%. The development of sustainable roll-to-roll printing processes that make use of Cu2ZnSnS4 (CZTS) nanoparticle inks requires the proper design of synthetic approaches and the understanding of the relation between process parameters and product purity. In the current paper, we developed this relationship by calculating a specific energy factor. A microwave-assisted synthetic method that operates at atmospheric pressure and makes use of eco-friendly solvents is established. Four solvents, i.e. ethylene glycol (EG), diethylene glycol (di-EG), triethylene glycol (tri-EG) and tetraethylene glycol (tet-EG) are compared and the temperature during the reaction is assessed by two different methods. In particular, two by-products have been identified, i.e. Cu2 - x S and a hexagonal phase. We show that the variation of reaction parameters such as power irradiation, type of solvent and precursor concentration influences the nanoparticles' sizes (from 12 to 6 nm) and also the temperature-time profile of reaction which, in turn, can be related to phase purity of CZTS nanoparticles. The results suggest that the product purity scales with the specific energy factor providing a useful tool to a rational design of high-quality CZTS nanoparticles.

Monitoring the Microbial Purity of the Treated Water and Dialysate

Directory of Open Access Journals (Sweden)

Canaud Bernard

2001-01-01

Full Text Available Dialysate purity has become a major concern in recent years since it has been proven that contamination of dialysate is able to induce the production of proinflammatory cytokines, putatively implicated in the development of dialysis related pathology. In order to reduce this risk, it is advised to use ultrapure dialysate as a new standard of dialysate purity. Ultrapure dialysate preparation may be easily achieved with modern water treatment technologies. The reliable production of ultrapure dialysate requires several prerequisites: use of ultrapure water, use of clean electrolytic concentrates, implementation of ultrafilters in the dialysate pathway to ensure cold sterilization of the fresh dialysate. The regular supply with such high-grade purity dialysate relies on predefined microbiological monitoring of the chain using adequate and sensitive methods, and hygienic handling including frequent disinfection to reduce the level of contamination and to prevent biofilm formation. Reliability of this process requires compliance with a very strict quality assurance process. In this paper, we summarized the principles of the dialysate purity monitoring and the criteria used for surveillance in order to establish good antimicrobial practices in dialysis.

Ion-exchange preparation of high-purity vanadium acid from industrial liquors

International Nuclear Information System (INIS)

Sajdakhmedov, U.A.; Arslanov, Sh.S.; Vulikh, A.I.

1994-01-01

The results of investigations on production of special-purity vanadium acid and vanadium oxide directly from process solutions (technical grade liquors) using ionites are presented. Potentiality of thorough purification of vanadium(5) oxide, when producing vanadium acid on the KU-2 cationite with subsequent purification on anionite, is shown. On the basis of the results obtained a principle flowsheet of ion-exchange production of high-purity vanadium(5) oxide from industrial liquors has been developed. 2 refs.; 1 fig.; 4 tabs

Disgust and the moralization of purity.

Science.gov (United States)

Horberg, E J; Oveis, Christopher; Keltner, Dacher; Cohen, Adam B

2009-12-01

Guided by appraisal-based models of the influence of emotion upon judgment, we propose that disgust moralizes--that is, amplifies the moral significance of--protecting the purity of the body and soul. Three studies documented that state and trait disgust, but not other negative emotions, moralize the purity moral domain but not the moral domains of justice or harm/care. In Study 1, integral feelings of disgust, but not integral anger, predicted stronger moral condemnation of behaviors violating purity. In Study 2, experimentally induced disgust, compared with induced sadness, increased condemnation of behaviors violating purity and increased approval of behaviors upholding purity. In Study 3, trait disgust, but not trait anger or trait fear, predicted stronger condemnation of purity violations and greater approval of behaviors upholding purity. We found that, confirming the domain specificity of the disgust-purity association, disgust was unrelated to moral judgments about justice (Studies 1 and 2) or harm/care (Study 3). Finally, across studies, individuals of lower socioeconomic status (SES) were more likely than individuals of higher SES to moralize purity but not justice or harm/care.

104 evaluation of microbiological purity of some brands of ...

African Journals Online (AJOL)

DR. AMINU

Keywords: Microbiological purity, tetracycline, contaminants, bacterial load, fungal load, microbiological ... Just like food substances, pharmaceutical products .... Malaysia. Chlortetracycline a. Mar. 2005. Mar. 2008. Ghana b. Aug. 2005. Aug.

Evaluation of measurement uncertainty for purity of a monoterpenic acid by small-scale coulometry

Science.gov (United States)

Norte, L. C.; de Carvalho, E. M.; Tappin, M. R. R.; Borges, P. P.

2018-03-01

Purity of the perylic acid (HPe) which is a monoterpenic acid from natural product (NP) with anti-inflammatory and anticancer properties was analyzed by small-scale coulometry (SSC), due to the low availability of HPe on the pharmaceutic market and its high cost. This work aims to present the evaluation of the measurements uncertainty from the purity of HPe by using SSC. Coulometric mean of purity obtained from 5 replicates resulted in 94.23% ± 0.88% (k = 2.06, for an approximately 95% confidence level). These studies aim in the future to develop the production of certified reference materials from NPs.

Preserving high-purity 233U

International Nuclear Information System (INIS)

Krichinsky, Alan; Giaquinto, Joe; Canaan, Doug

2016-01-01

The MARC X Conference hosted a workshop for the scientific community to communicate needs for high-purity 233 U and its by-products in order to preserve critical items otherwise slated for downblending and disposal. Currently, only small portions of the U.S. holdings of separated 233 U are being preserved. However, many additional kilograms of 233 U (>97 % pure) still are destined to be disposed, and it is unlikely that this material will ever be replaced due to a lack of operating production capability. Summaries of information conveyed at the workshop and feedback obtained from the scientific community are presented herein. (author)

Design of Unconstrained DMC to Improve the Distillate Product Purity of the Distillation Column

Directory of Open Access Journals (Sweden)

Bhat Vinayambika S.

2016-01-01

Full Text Available This paper demonstrates the use of unconstrained Dynamic Matrix Control (DMC to control the process transfer function with time delay. The selection of tuning parameter is challenging task in predictive control algorithm. The DMC scheme is designed and it is used here to control the process transfer function, First Order Plant with Dead Time (FOPDT model. Here, one manipulated variable (reflux and one controlled variable (distillate is considered for the implementation. The algorithm significantly controls the reflux to improve the distillate product purity. The simulation is done using MATLAB m-file. Both servo and regulatory responses were obtained. The simulation result validates the effectiveness of the proposed algorithm.

[Purity Detection Model Update of Maize Seeds Based on Active Learning].

Science.gov (United States)

Tang, Jin-ya; Huang, Min; Zhu, Qi-bing

2015-08-01

Seed purity reflects the degree of seed varieties in typical consistent characteristics, so it is great important to improve the reliability and accuracy of seed purity detection to guarantee the quality of seeds. Hyperspectral imaging can reflect the internal and external characteristics of seeds at the same time, which has been widely used in nondestructive detection of agricultural products. The essence of nondestructive detection of agricultural products using hyperspectral imaging technique is to establish the mathematical model between the spectral information and the quality of agricultural products. Since the spectral information is easily affected by the sample growth environment, the stability and generalization of model would weaken when the test samples harvested from different origin and year. Active learning algorithm was investigated to add representative samples to expand the sample space for the original model, so as to implement the rapid update of the model's ability. Random selection (RS) and Kennard-Stone algorithm (KS) were performed to compare the model update effect with active learning algorithm. The experimental results indicated that in the division of different proportion of sample set (1:1, 3:1, 4:1), the updated purity detection model for maize seeds from 2010 year which was added 40 samples selected by active learning algorithm from 2011 year increased the prediction accuracy for 2011 new samples from 47%, 33.75%, 49% to 98.89%, 98.33%, 98.33%. For the updated purity detection model of 2011 year, its prediction accuracy for 2010 new samples increased by 50.83%, 54.58%, 53.75% to 94.57%, 94.02%, 94.57% after adding 56 new samples from 2010 year. Meanwhile the effect of model updated by active learning algorithm was better than that of RS and KS. Therefore, the update for purity detection model of maize seeds is feasible by active learning algorithm.

Sorption-enhanced water gas shift reaction for high-purity hydrogen production: Application of a Na-Mg double salt-based sorbent and the divided section packing concept

International Nuclear Information System (INIS)

Lee, Chan Hyun; Lee, Ki Bong

2017-01-01

Highlights: •Na-Mg double salt-based sorbent was used for high-temperature CO 2 sorption. •Divided section packing concept was applied to the SE-WGS reaction. •High-purity H 2 was produced from the SE-WGS reaction with divided section packing. •High-purity H 2 productivity could be further enhanced by modifying packing method. -- Abstract: Hydrogen is considered a promising environmentally benign energy carrier because it has high energy density and produces no pollutants when it is converted into other types of energy. The sorption-enhanced water gas shift (SE-WGS) reaction, where the catalytic WGS reaction and byproduct CO 2 removal are carried out simultaneously in a single reactor, has received considerable attention as a novel method for high-purity hydrogen production. Since the high-purity hydrogen productivity of the SE-WGS reaction is largely dependent on the performance of the CO 2 sorbent, the development of sorbents having high CO 2 sorption capacity is crucial. Recently, a Na-Mg double salt-based sorbent has been considered for high-temperature CO 2 capture since it has been reported to have a high sorption capacity and fast sorption kinetics. In this study, the SE-WGS reaction was experimentally demonstrated using a commercial catalyst and a Na-Mg double salt-based sorbent. However, the SE-WGS reaction with a one-body hybrid solid, a physical admixture of catalyst and sorbent, showed poor reactivity and reduced CO 2 sorption uptake. As a result, a divided section packing concept was suggested as a solution. In the divided section packing method, the degree of mixing for the catalyst and sorbent in a column can be controlled by the number of sections. High-purity hydrogen (<10 ppm CO) was produced directly from the SE-WGS reaction with divided section packing, and the hydrogen productivity was further improved when the reactor column was divided into more sections and packed with more sorbent.

Production of thallium 201 for medical use

International Nuclear Information System (INIS)

Venikov, N.I.; Konyakhin, N.A.; Kozlova, M.D.; Volkova, N.M.

1986-01-01

An important product among the radiopharmaceuticals currently used in cardiology is T1 201 chloride, due to its nuclear-physical properties and its clinical value as a diagnostic tool. The authors explain and discuss the basic characteristics which determine the radiopharmaceutical quality of T1 201: its radiochemical purity and its chemical impurity content, which depend on the target-irradiation conditions - type of nuclear reaction, target material and design, particle energy, irradiation time - and the reprocessing technology. A production flow chart is presented which shows that ions are accelerated within a wide mass and energy range suitable for the production of T1 201 in different nuclear reactions. Cyclotron reconstruction for T1 201 production is discussed

High purity in steels as a criterion for materials development

International Nuclear Information System (INIS)

Jacobi, H.

1995-01-01

This summarizing report discusses the materials and application prospects for higher purity in steels, which will make possible further advances in materials behaviour and workability. Improvements in purity and homogeneity permit in particular more rational production of thin foils and wire, one-piece shaping of complicated bodywork components and the drawing, wall-ironing and flanging of two-piece beverage cans. Welded designs in plant and mechanical engineering can be fabricated with less effort and less weight. Difficult component geometries and shaping processes can be more easily mastered. Steels with optimized fracture toughness can be exposed to more extreme loads at even lower temperatures: applications worthy of mention include offshore engineering and large-diameter linepipes for use in arctic regions and at great underwater depths. Liquefied-gas transport vessels can be made more resistant to brittle rupture. The bending fatigue strength and service-life of valve-spring and rolling-bearing steels can be significantly increased. High-purity surfaces on piston rods and cylinders guarantee reliability in hydraulic systems, and high-purity calendering rolls permit defect-free embossing of paper surfaces. (orig.)

Design and development of fluidized bed reactor system for production of trichlorosilane as a precursor for high purity silicon

International Nuclear Information System (INIS)

Kumar, Rajesh; Mohan, Sadhana; Bhanja, K.; Nayak, S.; Bhattacharya, S.K.

2009-01-01

Trichlorosilane is widely used as precursor material for production of high purity silicon. It is mainly produced by reaction of metallurgical grade silicon with anhydrous HCl gas in a fluidized bed reactor. To develop this process on commercial scale a pilot size fluidized bed reactor system was designed and developed and successfully operated. This paper discusses the critical issues related to these activities. (author)

Biodiesel production using heterogeneous catalysts including wood ash and the importance of enhancing byproduct glycerol purity

International Nuclear Information System (INIS)

Uprety, Bijaya K.; Chaiwong, Wittavat; Ewelike, Chinomnso; Rakshit, Sudip K.

2016-01-01

Highlights: • Comparison of biodiesel production using homogeneous and heterogeneous catalysts. • Comparative study of CaO and CaO supported on alumina for biodiesel production. • Tradeoff between biodiesel conversion rate and purity. • Ash from birch bark and wood pellet industry explored as a potential catalyst. - Abstract: Transesterification of vegetable oils or animal fats with methanol in the presence of catalysts produces fatty acid methyl esters (FAME) and glycerol as a co-product. This study was focused on a comparative study of the transesterification of refined, bleached and deodorized palm oil (RBD palm oil) using a heterogeneous catalysts CaO with and without γ-alumina (γ-Al_2O_3) as a support. The results were also compared to that using sodium hydroxide (NaOH), which is a homogenous catalyst. Parameters like the amount of catalyst, the molar ratio of methanol to oil, reaction time and reaction temperature that affect methyl ester and glycerol formation were analyzed and the optimum conditions were determined. The FAME and glycerol content (96.75% and 92.73% respectively) obtained using CaO were lower in purity compared to that using CaO/Al_2O_3 (97.66% and 96.36% respectively). In the second phase of our work, wood ash from two different sources (birch bark & flyash from a biomass based power plant), which were calcined at 800 °C were studied for their potential use as a cheap renewable alternative heterogeneous catalyst. Both the wood ash samples were found to have good potential for use in such production process, but needs to be optimized further to obtain biodiesel which meets fuel biodiesel specifications. Both CaO and CaO supported on alumina produces FAME to levels that meet the fuel specifications required for blending with diesel. However, the latter produces a purer form of byproduct glycerol that can be easily converted to value added products, without the need for purification. On this basis the supported catalyst is

Capillary electrophoresis-based assessment of nanobody affinity and purity

NARCIS (Netherlands)

Haselberg, Rob; Oliveira, Sabrina; van der Meel, Roy; Somsen, Govert W; de Jong, Gerhardus J

2014-01-01

Drug purity and affinity are essential attributes during development and production of therapeutic proteins. In this work, capillary electrophoresis (CE) was used to determine both the affinity and composition of the biotechnologically produced "nanobody" EGa1, the binding fragment of a

Melt-drop technique for the production of high-purity metal powder

International Nuclear Information System (INIS)

Aldinger, F.; Linck, E.; Claussen, N.

1977-01-01

The production of high-purity powders of metals and alloys such as beryllium, titanium alloys, or superalloys is a problem. Oxidation of these materials cannot be avoided. Oxidation occurs in inert gases and even in reducing atmospheres when any gas impurities are present. Therefore, the powder production of these materials has to be performed either in high vacuum or at least in a static atmosphere of inert gas purified immediately before coming into contact with the disintegrating material. These requirements are very well met by the melt-drop technique presented in this paper, especially for coarse powders which must not necessarily be cold-workable. This is true, for example, for superalloys where high-temperature applications require large grain sizes; or in titanium alloys because the final microstructure will be achieved by a thermomechanical treatment. In the case of beryllium and beryllium alloys, where grain sizes <5 μm are desired, further milling is necessary. But the melt-drop technique offers a simple and clean method directly from the purifying process of vacuum melting. In melt-drop processes a liquid metal flows through a nozzle at the bottom of a crucible or the melt is just poured through a sieve. The theory of disintegration of a liquid jet into droplets, dates back to the 19th century. More recent investigations attempted to produce uniformly sized droplets by applying a capillary wave of given wave length to the jet. But this has been done only with non-metallic materials. Evidence is presented to prove the theory and show that this concept is applicable to the production of metal powders with controlled particle size

Production of high purity iodine-123 from xenon-124 at energies between 15 and 34 MeV

International Nuclear Information System (INIS)

Firouzbakht, M.L.; Teng Renrui; Schlyer, D.J.; Wolf, A.P.

1987-01-01

The production of I-123 from the proton bombardment of isotopically enriched Xe-124 is reported over the energy range of 15 to 34 MeV via the 124 Xe (p,pn) 123 Xe (β + , 2.1 hr) → 123 I and 124 Xe (p,2n) 123 Cs (β + , 6 min) → 123 Xe (β + , 2.1 hr) → 123 I pathways. The thick target yields for this target are tabulated and compared to theoretical cross-section calculations of the nuclear reactions leading to the production of Xe-123. The radiochemical purity of the I-123 is greater than 99.9% and the contamination of I-125 is below detectable limits (< 0.1%) at 6.6 hrs after the end of bombardment. (orig.)

In vitro characterization of high purity factor IX concentrates for the treatment of hemophilia B.

Science.gov (United States)

Limentani, S A; Gowell, K P; Deitcher, S R

1995-04-01

This study employed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and immunoblotting to assess the purity of seven high purity factor IX concentrates: Aimafix (Aima), AlphaNine-SD (Alpha Therapeutic), Factor IX VHP (Biotransfusion), Immunine (Immuno), Mononine (Armour Pharmaceutical), Nanotiv (Kabi Pharmacia), and 9MC (Blood Products Laboratory). The mean specific activity of these products ranged from 68 U factor IX/mg (Aimafix) to 246 U factor IX/mg (Mononine). SDS-PAGE analysis showed that the highest purity product, Mononine, had a single contaminating band under non-reducing conditions. Two additional bands were detected when this product was analyzed under reducing conditions. All other products had multiple contaminating bands that were more apparent under reducing than non-reducing conditions. The immunoblot for factor IX showed a dominant factor IX band for all products. In addition, visible light chain of factor IX was detected for AlphaNine-SD, Factor IX VHP, Immunine, Mononine, Nanotiv, and 9MC, suggesting that the factor IX in these products had undergone partial activation to factor IXa. Another contaminating band was visible at 49,500 for all of the products except 9MC. In addition to this band, high molecular weight contaminants were apparent for some products, most notably AlphaNine-SD. The identity of these bands is unknown. Immunoblotting failed to demonstrate factor VII as a contaminant of any of the high purity products, although factor VIIa could be detected in some lots of Immunine, Nanotiv, and 9MC by a clot-based assay. Factor X contaminated Aimafix, AlphaNine-SD, Factor IX VHP, Immunine, Nanotiv, and 9MC, but activation products of factor X were not detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermal conductivity of high purity vanadium

International Nuclear Information System (INIS)

Jung, W.D.

1975-01-01

The thermal conductivity, Seebeck coefficient, and electrical resistivity of four high-purity vanadium samples were measured over the temperature range 5 to 300 0 K. The highest purity sample had a resistance ratio (rho 273 /rho 4 . 2 ) of 1524. The highest purity sample had a thermal conductivity maximum of 920 W/mK at 9 0 K and had a thermal conductivity of 35 W/mK at room temperature. At low temperatures, the thermal resistivity was limited by the scattering of electrons by impurities and phonons. The thermal resistivity of vanadium departed from Matthiessen's rule at low temperatures. The electrical resistivity and Seebeck coefficient of high purity vanadium showed no anomalous behavior above 130 0 K. The intrinsic electrical resistivity at low temperatures was due primarily to interband scattering of electrons. The Seebeck coefficient was positive from 10 to 240 0 K and had a maximum which was dependent upon sample purity

Radiation sterilization of medical products

International Nuclear Information System (INIS)

Khurshid, S.J.; Hussain, A.M.

1989-01-01

Radiation sterilization is the best method of sterilization, essentially for single use medical and surgical products. Pakistan has established a commercial gamma irradiation plant for this purpose. This article overviews the advantages and benefits of radiation sterilization to stimulate the interest of industrialists and the users in this technology. This technology can give a better medical care in the country and the growing demand can only be met by bulk sterilization. The radiation sterilized medical products can also compete well with the products sterilized by other methods in the international market, gamma sterilization is accepted internationally and if adopted it can boost our export of medical products. (author)

Imaging Scanner Usage in Radiochemical Purity Test

International Nuclear Information System (INIS)

Norhafizah Othman; Yahaya Talib; Wan Hamirul Bahrin Wan Kamal

2011-01-01

Imaging Scanner model BIOSCAN AR-2000 has been used in the radiochemical purity test for the product of Mo-99/ Tc-99m generator. Result from this test was produced directly where the percentage of pertechnetate was calculated based on width peak area by thin layer chromatography. This paperwork will explain the function, procedure, calibration of the instrument and discussed the advantages compared to the previous method. (author)

Production of R,R-2,3-butanediol of ultra-high optical purity from Paenibacillus polymyxa ZJ-9 using homologous recombination.

Science.gov (United States)

Zhang, Li; Cao, Can; Jiang, Ruifan; Xu, Hong; Xue, Feng; Huang, Weiwei; Ni, Hao; Gao, Jian

2018-08-01

The present study describes the use of metabolic engineering to achieve the production of R,R-2,3-butanediol (R,R-2,3-BD) of ultra-high optical purity (>99.99%). To this end, the diacetyl reductase (DAR) gene (dud A) of Paenibacillus polymyxa ZJ-9 was knocked out via homologous recombination between the genome and the previously constructed targeting vector pRN5101-L'C in a process based on homologous single-crossover. PCR verification confirmed the successful isolation of the dud A gene disruption mutant P. polymyxa ZJ-9-△dud A. Moreover, fermentation results indicated that the optical purity of R,R-2,3-BD increased from about 98% to over 99.99%, with a titer of 21.62 g/L in Erlenmeyer flasks. The latter was further increased to 25.88 g/L by fed-batch fermentation in a 5-L bioreactor. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis of high purity monoglycerides from crude glycerol and palm stearin

Directory of Open Access Journals (Sweden)

Pakamas Chetpattananondh

2008-07-01

Full Text Available The optimum conditions for the glycerolysis of palm stearin and crude glycerol derived from biodiesel process werefound to be a reaction temperature of 200oC with a molar ratio of crude glycerol to palm stearin of 2.5:1, and a reaction timeof 20 minutes. The yield and purity of monoglycerides obtained under these conditions was satisfactory as compared withthe glycerolysis of pure glycerol. To increase the purity of monoglycerides a two-step process, removal of residual glyceroland crystallization, was proposed instead of either vacuum or molecular distillation. Residual glycerol was removed byadding hydrochloric acid followed by washing with hot water. Optimum conditions for crystallization were achieved byusing isooctane as a solvent and a turbine impeller speed of 200 rpm at a crystallization temperature of 35oC. A purity notexceeding 99 percent of monoglycerides was obtained with monopalmitin as the major product.

Fused salt processing of impure plutonium dioxide to high-purity plutonium metal

International Nuclear Information System (INIS)

Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

1982-01-01

A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool

History of medical radionuclide production.

Science.gov (United States)

Ice, R D

1995-11-01

Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

High purity radioactive beams at the bevalac

International Nuclear Information System (INIS)

Alonso, J.R.; Chatterjee, A.; Tobias, C.A.

1979-03-01

Peripheral nuclear fragmentation reactions of primary Bevalac heavy ion beams are used to produce secondary beams of radioactive nuclei. The large cross section and small deflection of the projectile fragments lead to high production and delivery efficiency for these beams. Dispersive beam transport allows good separation and purification of the desired secondary beams. 11 C and 19 Ne beams of high purity and good intensity (almost 0.2% of the primary beam current) are presently being used for biomedical experiments

Improved fed-batch production of high-purity PHB (poly-3 hydroxy butyrate) by Cupriavidus necator (MTCC 1472) from sucrose-based cheap substrates under response surface-optimized conditions.

Science.gov (United States)

Dey, Pinaki; Rangarajan, Vivek

2017-10-01

Experimental investigations were carried out for Cupriavidus necator (MTCC 1472)-based improved production of poly-3 hydroxy butyrate (PHB) through induced nitrogen limiting fed-batch cultivation strategies. Initially Plackett-Burman design and response surface methodology were implemented to optimize most influencing process parameters. With optimized process parameter values, continuous feeding strategies ware applied in a 5-l fermenter with table sugar concentration of 100 g/l, nitrogen concentration of 0.12 g/l for fed-batch fermentation with varying dilution rates of 0.02 and 0.046 1/h. To get enriched production of PHB, concentration of the sugar was further increased to 150 and 200 g/l in feeding. Maximum concentrations of PHB achieved were 22.35 and 23.07 g/l at those dilution rates when sugar concentration maintains at 200 g/l in feeding. At maximum concentration of PHB (23.07 g/l), productivity of 0.58 g/l h was achieved with maximum PHB accumulation efficiency up to 64% of the dry weight of biomass. High purity of PHB, close to medical grade was achieved after surfactant hypochlorite extraction method, and it was further confirmed by SEM, EDX, and XRD studies.

Establishing comparability and compatibility in the purity assessment of high purity zinc as demonstrated by the CCQM-P149 intercomparison

Science.gov (United States)

Vogl, Jochen; Kipphardt, Heinrich; Richter, Silke; Bremser, Wolfram; del Rocío Arvizu Torres, María; Manzano, Judith Velina Lara; Buzoianu, Mirella; Hill, Sarah; Petrov, Panayot; Goenaga-Infante, Heidi; Sargent, Mike; Fisicaro, Paola; Labarraque, Guillaume; Zhou, Tao; Turk, Gregory C.; Winchester, Michael; Miura, Tsutomu; Methven, Brad; Sturgeon, Ralph; Jährling, Reinhard; Rienitz, Olaf; Mariassy, Michal; Hankova, Zuzana; Sobina, Egor; Ivanovich Krylov, Anatoly; Anatolievich Kustikov, Yuri; Vladimirovich Smirnov, Vadim

2018-04-01

For the first time, an international comparison was conducted on the determination of the purity of a high purity element. Participants were free to choose any analytical approach appropriate for their institute’s applications and services. The material tested was a high purity zinc, which had earlier been assessed for homogeneity and previously used in CCQM-K72 for the determination of six defined metallic impurities. Either a direct metal assay of the Zn mass fraction was undertaken by EDTA titrimetry, or an indirect approach was used wherein all impurities, or at least the major ones, were determined and their sum subtracted from ideal purity of 100%, or 1 kg kg-1. Impurity assessment techniques included glow discharge mass spectrometry, inductively coupled plasma mass spectrometry and carrier gas hot extraction/combustion analysis. Up to 91 elemental impurities covering metals, non-metals and semi-metals/metalloids were quantified. Due to the lack of internal experience or experimental capabilities, some participants contracted external laboratories for specific analytical tasks, mainly for the analysis of non-metals. The reported purity, expressed as zinc mass fraction in the high purity zinc material, showed excellent agreement for all participants, with a relative standard deviation of 0.011%. The calculated reference value, w(Zn)  =  0.999 873 kg kg-1, was assigned an asymmetric combined uncertainty of  +0.000 025 kg kg-1 and  -0.000 028 kg kg-1. Comparability amongst participating metrology institutes is thus demonstrated for the purity determination of high purity metals which have no particular difficulties with their decomposition/dissolution process when solution-based analytical methods are used, or which do not have specific difficulties when direct analysis approaches are used. Nevertheless, further development is required in terms of uncertainty assessment, quantification of non-metals and the determination of purity

Analysis of the Purity of Cetrimide by Titrations

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov; Rasmussen, Claus/Dallerup; Nielsen, Hans/Boye

2006-01-01

. Titration by perchloric acid showed a 99.69 ± 0.05 % purity of cetrimide and titration by silver nitrate showed a 99.85% ± 0.05 % purity while the traditional assay method predicted a purity of only 97.1 ± 0.4. It was found that the discrepancy could be identified as differences in selectivity during...

Construction, assembling and operation of an equipment for sodium purity

International Nuclear Information System (INIS)

Becquart, E.T.; Botbol, J.; Echenique, P.N.; Fruchtenicht, F.W.; Gil, D.A.; Perillo, P.; Vardich, R.N.; Vigo, D.E.

1993-01-01

The purpose of this work is the production of high purity metallic sodium for bench-scale, research studies. A stainless steel equipment was built and assembled, including high vacuum, heating and cooling systems. It was satisfactorily operated in two successive steps, filtration and vacuum distillation, with a good yield. (Author). 5 refs., 5 figs

Comparative Studies on the Radiolabeling and Chromatographic Purification of Some Medically Important Compounds

International Nuclear Information System (INIS)

El-Gizawy, M.A.E.

2013-01-01

The present thesis comprises five basic chapters: The first chapter includes the main idea of our study and its problems, also includes the aim of the work of our study. The second chapter includes the theoretical consideration of the subject. It deals with the general methods of labeling, factors that influence the integrity of labeled compounds, radionuclides used for diagnostic nuclear medicine, production methods and radioactive properties of 123 I, 125 I and 131 I. It includes also the techniques used for the preparation of the radioiodinated compounds especially the electrophilic radioiodination technique. This chapter deals also with the medical imaging, techniques of diagnostic nuclear medicine and the purification of radioiodinated compounds using different chromatographic techniques. Since these radioiodinated compounds are used for diagnosis and therapeutic treatment of human diseases, quality control tests such as determination of chemical purity, radionuclidic purity, radiochemical purity, sterility, pyrogenicity and biodistribution are performed to ensure the purity, the safety and efficiency of these products for the intended nuclear medicine application. The third chapter describes the experimental section; comprising chemicals, reagents, the radionuclides, the equipments and the counting systems used in the study. It describes the electrophilic radioiodination using chloramine-T (CAT), iodogen and lactoperoxidase oxidizing agents and the factors affecting the radiochemical yield of the radioiodination of histamine and L-tyrosine methyl ester such as substrate concentration, ph of the medium, reaction time, temperature and stability of the labeled product. This chapter also includes the techniques used in the Purification of radioiodinated compounds, including paper electrophoresis, thin layer chromatography (TLC), Poly acrylamide-acrylic acid resin [P(AAm-AA) resin] and high performance liquid chromatography (HPLC), in addition, the quality control

Purity assessment of recombinant human granulocyte colony-stimulating factor in finished drug product by capillary zone electrophoresis.

Science.gov (United States)

Benković, Goran; Skrlin, Ana; Madić, Tomislav; Debeljak, Zeljko; Medić-Šarić, Marica

2014-09-01

Current methods for determination of impurities with different charge-to-volume ratio are limited especially in terms of sensitivity and precision. The main goal of this research was to establish a quantitative method for determination of impurities with charges differing from that of recombinant human granulocyte colony-stimulating factor (rhG-CSF, filgrastim) with superior precision and sensitivity compared to existing methods. A CZE method has been developed, optimized, and validated for a purity assessment of filgrastim in liquid pharmaceutical formulations. Optimal separation of filgrastim from the related impurities with different charges was achieved on a 50 μm id fused-silica capillary of a total length of 80.5 cm. A BGE that contains 100 mM phosphoric acid adjusted to pH 7.0 with triethanolamine was used. The applied voltage was 20 kV while the temperature was maintained at 25°C. UV detection was set to 200 nm. Method was validated in terms of selectivity/specificity, linearity, precision, LOD, LOQ, stability, and robustness. Linearity was observed in the concentration range of 6-600 μg/mL and the LOQ was determined to be 0.3% relative to the concentration of filgrastim of 0.6 mg/mL. Other validation parameters were also found to be acceptable; thus the method was successfully applied for a quantitative purity assessment of filgrastim in a finished drug product. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large-scale purification of 90Sr from nuclear waste materials for production of 90Y, a therapeutic medical radioisotope.

Science.gov (United States)

Wester, Dennis W; Steele, Richard T; Rinehart, Donald E; DesChane, Jaquetta R; Carson, Katharine J; Rapko, Brian M; Tenforde, Thomas S

2003-07-01

A major limitation on the supply of the short-lived medical isotope 90Y (t1/2 = 64 h) is the available quantity of highly purified 90Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1,500 Ci of 90Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of 137Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid 90Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for 90Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of 90Sr immobilized on stainless steel filters for future use.

Large-scale purification of 90Sr from nuclear waste materials for production of 90Y, a therapeutic medical radioisotope

International Nuclear Information System (INIS)

Wester, D.W.; Steele, R.T.; Rinehart, D.E.; DesChane, J.R.; Carson, K.J.; Rapko, B.M.; Tenforde, T.S.

2003-01-01

A major limitation on the supply of the short-lived medical isotope 90 Y (t 1/2 =64 h) is the available quantity of highly purified 90 Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1500 Ci of 90 Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of 137 Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid 90 Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for 90 Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of 90 Sr immobilized on stainless steel filters for future use

Kit preparation of 153Sm-EDTMP and factors affecting radiochemical purity and stability

International Nuclear Information System (INIS)

Ferro-Flores, G.; Tendilla, J.I.; Lopez-Gomez, M.A.; Aguilar-Hernandez, F.; Gonzalez-Zavala, M.A.; Parades-Gutierrez, L.; Avila-Ramirez, E.

1996-01-01

A fast kit method was developed for the production of 153 Sm-EDTMP in two steps avoiding the use of nitric acid, evaporation and sterilization of the final solution by autoclave. Methods of analysis for the determination of chemical and radiochemical purity in the radiopharmaceutical solution were established. Factors affecting radiochemical purity and stability of the complex as the molar ratio of EDTMP/Sm, concentration of phosphate buffer and neutralization of EDTMP prior kit preparation were also analyzed. The use of this radiopharmaceutical in rabbits and patients showed selective skeletal uptake. (author). 5 refs., 4 figs., 3 tabs

Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods.

Science.gov (United States)

Singh, Nahar; Singh, Niranjan; Tripathy, S Swarupa; Soni, Daya; Singh, Khem; Gupta, Prabhat K

2013-06-26

A conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stick in 5% ultra pure nitric acid. From the stock solution five replicates of approximate 50 g have been taken for determination of purity by each method. The Pb has been determined as PbSO4 by conventional gravimetry, as PbO2 by electro gravimetry. The percentage purity of the metallic Pb was calculated accordingly from PbSO4 and PbO2. On the basis of experimental observations it has been concluded that by conventional gravimetry and electro-gravimetry the purity of Pb was found to be 99.98 ± 0.24 and 99.97 ± 0.27 g/100 g and on the basis of Pb purity the concentration of reference standard solutions were found to be 1000.88 ± 2.44 and 1000.81 ± 2.68 mg kg-1 respectively with 95% confidence level (k = 2). The uncertainty evaluation has also been carried out in Pb determination following EURACHEM/GUM guidelines. The final analytical results quantifying uncertainty fulfills this requirement and gives a measure of the confidence level of the concerned laboratory. Gravimetry is the most reliable technique in comparison to titremetry and instrumental method and the results of gravimetry are directly traceable to SI unit. Gravimetric analysis, if methods are followed carefully, provides for exceedingly precise analysis. In classical gravimetry the major uncertainties are due to repeatability but in electro-gravimetry several other factors also affect the final results.

Production of High-purity Magnetite Nanoparticles from a Low-grade Iron Ore via Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Suh, Yong Jae; Kil, Dae Sup; Jang, Hee Dong [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Do, Thi May [Korea University of Science and Technology, Daejeon (Korea, Republic of); Cho, Kuk [Pusan National University, Busan (Korea, Republic of)

2015-02-15

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity Fe{sup 3+} solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of Mg{sup 2+} and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-ore-wastewater treatments, as well as in the economic production of the nano-adsorbent.

Policosanol extraction from beeswax and improvement of the purity

Directory of Open Access Journals (Sweden)

Srisaipet Anakhaorn

2017-01-01

Full Text Available Policosanol is a mixture of high molecular weight aliphatic long chain alcohols (20-36 carbon atoms. It has been use in pharmaceutical composition and food supplements. This research aimed to isolate and improve the purity of policosanol extracted from beeswax. Triglycerides and other impurities were eliminated from beeswax by refluxing with hexane followed by isopropanol. The purified beeswax was hydrolyzed by refluxing with 1 M ethanolic NaOH for 2 hours. Purification of policosanol was performed by extracting the hydrolyzed product with acetone at 50-60 °C for 3 hours and it was stored at 4 °C for precipitation. The precipitate was refluxed with heptanes followed by washing with hot water. The heptanes layer was kept for policosanol precipitation at 4 °C. The purity of policosanol was confirmed by TLC and high performance liquid chromatography (HPLC. The yield of purified policosanol was 13.23-13.89 %.

Open fermentative production of L-lactic acid with high optical purity by thermophilic Bacillus coagulans using excess sludge as nutrient.

Science.gov (United States)

Ma, Kedong; Maeda, Toshinari; You, Huiyan; Shirai, Yoshihito

2014-01-01

The development of a low-cost polymer-grade L-lactic acid production process was achieved in this study. Excess sludge hydrolyzate (ESH) was chosen as nutrient source for the objective of reducing nutrient cost in lactic acid production. 1% of ESH had high performance in lactic acid production relative to 2g/l yeast extract (YE) while the production cost of ESH was much lower than that of YE, indicating ESH was a promising substitute of YE. By employing a thermophilic strain of Bacillus coagulans (NBRC 12583), non-sterilized batch and repeated batch L-lactic acid fermentation was successfully performed, and the optical purity of L-lactic acid accumulated was more than 99%. Moreover, the factors associated with cell growth and lactic acid fermentation was investigated through a two-stage lactic acid production strategy. Oxygen played an important role in cell growth, and the optimal condition for cell growth and fermentation was pH 7.0 and 50°C. Copyright © 2013 Elsevier Ltd. All rights reserved.

An ICP AES method for determination of dysprosium and terbium in high purity yttrium oxide

International Nuclear Information System (INIS)

Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.

2011-01-01

High purity yttrium finds interesting application in astronavigation, luminescence, nuclear energy and metallurgical industries. Most of these applications require yttrium oxide of highest purity. Consequently there is a need for production of high purity yttrium oxide. Separation and purification of yttrium from other rare earths is a challenging task due to their close chemical properties. Liquid-liquid extraction and ion exchange have been widely used in the production of yttrium oxide of highest purity. Determination of impurities, especially other rare earths, in ppm level is required for process development and chemical characterization of the high purity Y 2 O 3 . Many methods have been described in literature. However since the advent of ICP AES much work in this area has been carried out by this technique. This paper describes the work done for determination of dysprosium (Dy) and terbium (Tb) in yttrium oxide using a high resolution sequential ICP AES. Emission spectra of rare earth elements are very complex and due to this complexity it is important to select spectral interference free analyte lines for determination of rare earths in rare earth matrix. For the determination of Dy and Tb in Y 2 O 3 , sensitive lines of Dy and Tb are selected from the instrument wavelength table and spectral interference free emission lines for the determination is selected by scanning around the selected wavelengths using 5 g/L Y solution and 5 mg/L standard solutions of Dy and Tb prepared in 4% nitric acid. It is found 353.170 nm line of Dy and 350.917 nm line Tb is suitable for quantitative determination. The signal to background ratio increases with increase in matrix concentration, i.e. from 1 to 5 mg/L. The optimum forward power is determined and it is found to be 1100W for Dy and 1000W for Tb. The instrument is calibrated using matrix matched standards containing 5g/L of Y matrix. Samples are dissolved in nitric acid and Y concentration is maintained at 5g/L. Two

Production of Medical Isotopes with Electron Linacs

Energy Technology Data Exchange (ETDEWEB)

Rotsch, D A; Alford, K.; Bailey, J. L.; Bowers, D. L.; Brossard, T.; Brown, M. A.; Chemerisov, S. D.; Ehst, D.; Greene, J.; Gromov, R. G.; Grudzinski, J.J.; Hafenrichter, L.; Hebden, A. S.; Henning, W.; Heltemes, T. A.; Jerden, J.; Jonah, C. D.; Kalensky, M.; Krebs, J. F.; Makarashvili, V.; Micklich, B.; Nolen, J.; Quigley, K. J.; Schneider, J. F.; Smith, N. A.; Stepinski, D. C.; Sun, Z.; Tkac, P.; Vandegrift, G. F.; Virgo, M J; Wesolowski, K. A.; Youker, A. J.

2017-06-01

Radioisotopes play important roles in numerous areas ranging from medical treatments to national security and basic research. Radionuclide production technology for medical applications has been pursued since the early 1900s both commercially and in nuclear science centers. Many medical isotopes are now in routine production and are used in day-to-day medical procedures. Despite these advancements, research is accelerating around the world to improve the existing production methodologies as well as to develop novel radionuclides for new medical appli-cations. Electron linear accelerators (linacs) represent a unique method for the production of radioisotopes. Even though the basic technology has been around for decades, only recently have electron linacs capable of producing photons with sufficient energy and flux for radioisotope production become available. Housed in Argonne Nation-al Laboratory’s Low Energy Accelerator Facility (LEAF) is a newly upgraded 55 MeV/25-kW electron linear ac-celerator, capable of producing a wide range of radioiso-topes. This talk will focus on the work being performed for the production of the medical isotopes 99Mo (99Mo/99mTc generator), 67Cu, and 47Sc.

10 CFR 36.63 - Pool water purity.

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Pool water purity. 36.63 Section 36.63 Energy NUCLEAR... § 36.63 Pool water purity. (a) Pool water purification system must be run sufficiently to maintain the conductivity of the pool water below 20 microsiemens per centimeter under normal circumstances. If pool water...

High purity neodymium acetate from mixed rare earth carbonates

International Nuclear Information System (INIS)

Queiroz, Carlos A. da Silva; Rocha, Soraya M. Rizzo da; Vasconcellos, Mari E. de; Lobo, Raquel M.; Seneda, Jose A.; Pedreira, Walter dos R.

2011-01-01

A simple and economical chemical process for obtaining high purity neodymium acetate is discussed. The raw material in the form rare earth carbonate is produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography technique with a strong cationic resin, proper to water treatment, and without the use of retention ions was used for the fractionating of the rare earth elements (REE). In this way, it was possible to obtain 99.9% pure Nd 2 O 3 in yields greater than or equal 80%, with the elution of the REE using ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in pH controlled. The complex of EDTA-neodymium was transformed into neodymium oxide, which was subsequently dissolved in acetic acid to obtain the neodymium acetates. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium acetates. The typical neodymium acetates obtained contain the followings contaminants in μg g -1 : Sc(5.1); Y (0.9); La (1.0); Ce (6.1); Pr (34,4); Sm (12.8); Eu (1.1); Gd (15.4); Tb (29.3); Dy (5.2), Ho(7.4); Er (14.6); Tm (0.3); Yb (2.5); Lu (1.0). The high purity neodymium acetates obtained from this procedure have been applied, replacing the imported product, in research and development area on rare earth catalysts. (author)

High purity zirconium obtainment through the iodine compounds transport method

International Nuclear Information System (INIS)

Bolcich, J.C.; Zuzek, E.; Dutrus, S.M.; Corso, H.L.

1987-01-01

This paper describes the experimental method and the equipment designed, constructed and actually applied for the high purity zirconium obtainment from a zirconium sponge of the nuclear type. The mechanism of purification is based on the impure metal attack with gaseous iodine (at 200 deg C) to obtain zirconium tetra iodine as main product which is then transformed into a pure zirconium base (at 1000-1300 deg C), precipitating the metallic zirconium and releasing the gaseous iodine. From the first experiences carried out, pure zirconium has been obtained from an initial filament of 0.5 mm of diameter as well as wires up to 2.5 mm of diameter. This work presents the results from the studies and analysis made to characterize the material obtained. Finally, the refining methods to which the zirconium produced may be submitted so as to optimize the final purity are discussed. (Author)

Medical ice slurry production device

Science.gov (United States)

Kasza, Kenneth E [Palos Park, IL; Oras, John [Des Plaines, IL; Son, HyunJin [Naperville, IL

2008-06-24

The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

Strengthening Purity: Moral Purity as a Mediator of Direct and Extended Cross-Group Friendships on Sexual Prejudice.

Science.gov (United States)

Vezzali, Loris; Brambilla, Marco; Giovannini, Dino; Paolo Colucci, Francesco

2017-01-01

The present research investigated whether enhanced perceptions of moral purity drive the effects of intergroup cross-group friendships on the intentions to interact with homosexuals. High-school students (N = 639) reported their direct and extended cross-group friendships with homosexuals as well as their beliefs regarding the moral character of the sexual minority. Participants further reported their desire to interact with homosexuals in the future. Results showed that both face-to-face encounters and extended contact with homosexuals increased their perceived moral purity, which in turn fostered more positive behavioral intentions. Results further revealed the specific role of moral purity in this sense, as differential perceptions along other moral domains (autonomy and community) had no mediation effects on behavioral tendencies toward homosexuals. The importance of these findings for improving intergroup relations is discussed, together with the importance of integrating research on intergroup contact and morality.

The production of radionuclides for nuclear medicine from a compact, low-energy accelerator system.

Science.gov (United States)

Webster, William D; Parks, Geoffrey T; Titov, Dmitry; Beasley, Paul

2014-05-01

The field of nuclear medicine is reliant on radionuclides for medical imaging procedures and radioimmunotherapy (RIT). The recent shut-downs of key radionuclide producers have highlighted the fragility of the current radionuclide supply network, however. To ensure that nuclear medicine can continue to grow, adding new diagnostic and therapy options to healthcare, novel and reliable production methods are required. Siemens are developing a low-energy, high-current - up to 10 MeV and 1 mA respectively - accelerator. The capability of this low-cost, compact system for radionuclide production, for use in nuclear medicine procedures, has been considered. The production of three medically important radionuclides - (89)Zr, (64)Cu, and (103)Pd - has been considered, via the (89)Y(p,n), (64)Ni(p,n) and (103)Rh(p,n) reactions, respectively. Theoretical cross-sections were generated using TALYS and compared to experimental data available from EXFOR. Stopping power values generated by SRIM have been used, with the TALYS-generated excitation functions, to calculate potential yields and isotopic purity in different irradiation regimes. The TALYS excitation functions were found to have a good agreement with the experimental data available from the EXFOR database. It was found that both (89)Zr and (64)Cu could be produced with high isotopic purity (over 99%), with activity yields suitable for medical diagnostics and therapy, at a proton energy of 10MeV. At 10MeV, the irradiation of (103)Rh produced appreciable quantities of (102)Pd, reducing the isotopic purity. A reduction in beam energy to 9.5MeV increased the radioisotopic purity to 99% with only a small reduction in activity yield. This work demonstrates that the low-energy, compact accelerator system under development by Siemens would be capable of providing sufficient quantities of (89)Zr, (64)Cu, and (103)Pd for use in medical diagnostics and therapy. It is suggested that the system could be used to produce many other

Helium gas purity monitor based on low frequency acoustic resonance

Science.gov (United States)

Kasthurirengan, S.; Jacob, S.; Karunanithi, R.; Karthikeyan, A.

1996-05-01

Monitoring gas purity is an important aspect of gas recovery stations where air is usually one of the major impurities. Purity monitors of Katherometric type are commercially available for this purpose. Alternatively, we discuss here a helium gas purity monitor based on acoustic resonance of a cavity at audio frequencies. It measures the purity by monitoring the resonant frequency of a cylindrical cavity filled with the gas under test and excited by conventional telephone transducers fixed at the ends. The use of the latter simplifies the design considerably. The paper discusses the details of the resonant cavity and the electronic circuit along with temperature compensation. The unit has been calibrated with helium gas of known purities. The unit has a response time of the order of 10 minutes and measures the gas purity to an accuracy of 0.02%. The unit has been installed in our helium recovery system and is found to perform satisfactorily.

Optimization of hydrogen production with CO_2 capture by autothermal chemical-looping reforming using different bioethanol purities

International Nuclear Information System (INIS)

García-Díez, E.; García-Labiano, F.; De Diego, L.F.; Abad, A.; Gayán, P.; Adánez, J.; Ruíz, J.A.C.

2016-01-01

Highlights: • Autothermal-CLR and WGS have been considered for H_2 production with CO_2 capture. • Bioethanol was used as renewable fuel. • Mass and heat balances allow process optimization. • The use of diluted bioethanol implies energy saves in the bioethanol production. • The use of diluted bioethanol (52 vol.%) produces 4.62 mol H_2/mol ethanol. - Abstract: Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO_2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N_2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries. In this work, mass and heat balances were done to determine the auto-thermal conditions that maximize H_2 production, assuming that the product gas was in thermodynamic equilibrium. Three different types of bioethanol has been considered according to their ethanol purity; Dehydrated ethanol (≈100 vol.%), hydrated ethanol (≈96 vol.%), and diluted ethanol (≈52 vol.%). It has been observed that the higher H_2 production (4.62 mol of H_2 per mol of EtOH) has been obtained with the use of diluted ethanol and the surplus energy needed could be compensated by the energy save achieved during the purification of ethanol in the production process.

Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

Science.gov (United States)

Aydın, Güral; Usta, Metin; Oktay, Adem

2018-06-01

Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

High purity samarium oxide from mixed rare earth carbonates

International Nuclear Information System (INIS)

Queiroz, Carlos A. da S.; Seneda, Jose A.; Vasconcellos, Mari E. de; Pedreira Filho, Walter dos R.

2013-01-01

A simple and economical chemical process for the production of highly pure samarium oxides is discussed. The raw material, which was used in the form of rare earth carbonates was produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography was performed using a strong cationic resin that is typically employed in water treatment processes to fractionate rare earth elements (REE) without the use of retention ions. Under these conditions, 99.9% pure Sm 2 O 3 was eluted using the ammonium salt of ethylenediaminetetraacetic acid (EDTA) at a controlled pH. The EDTA-samarium complex was separated from EDTA and then precipitated as oxalate and fired to samarium oxide. Molecular absorption spectrophotometry was used to monitor the samarium content during the proposed process, and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the samarium oxide. Typical samarium oxide obtained from the proposed procedure contained the following contaminants in micrograms per gram: Sc (20.90); Y (11.80); La (8.4); Ce (4.3); Pr (2.5); Nd (5.1); Eu (94); Gd (114); Tb (3.6); Dy (2.5), Ho (2.3); Er (3.0); Tm (2.3); Yb (38,2); Lu (25.6). The high-purity samarium oxides produced in the present study can be used as an alternative to imported products in research and development applications. (author)

Uncertainty estimates of purity measurements based on current information: toward a "live validation" of purity methods.

Science.gov (United States)

Apostol, Izydor; Kelner, Drew; Jiang, Xinzhao Grace; Huang, Gang; Wypych, Jette; Zhang, Xin; Gastwirt, Jessica; Chen, Kenneth; Fodor, Szilan; Hapuarachchi, Suminda; Meriage, Dave; Ye, Frank; Poppe, Leszek; Szpankowski, Wojciech

2012-12-01

To predict precision and other performance characteristics of chromatographic purity methods, which represent the most widely used form of analysis in the biopharmaceutical industry. We have conducted a comprehensive survey of purity methods, and show that all performance characteristics fall within narrow measurement ranges. This observation was used to develop a model called Uncertainty Based on Current Information (UBCI), which expresses these performance characteristics as a function of the signal and noise levels, hardware specifications, and software settings. We applied the UCBI model to assess the uncertainty of purity measurements, and compared the results to those from conventional qualification. We demonstrated that the UBCI model is suitable to dynamically assess method performance characteristics, based on information extracted from individual chromatograms. The model provides an opportunity for streamlining qualification and validation studies by implementing a "live validation" of test results utilizing UBCI as a concurrent assessment of measurement uncertainty. Therefore, UBCI can potentially mitigate the challenges associated with laborious conventional method validation and facilitates the introduction of more advanced analytical technologies during the method lifecycle.

Neutron activation analysis of high purity tellurium

International Nuclear Information System (INIS)

Gil'bert, Eh.N.; Verevkin, G.V.; Obrazovskij, E.G.; Shatskaya, S.S.

1980-01-01

A scheme of neutron activation analysis of high purity tellurium is developed. Weighed amount of Te (0.5 g) is irradiated for 20-40 hr in the flux of 2x10 13 neutron/(cm 2 xs). After decomposition of the sample impurities of gold and palladium are determined by the extraction with organic sulphides. Tellurium separation from the remaining impurities is carried out by the extraction with monothiobenzoic acid from weakly acidic HCl solutions in the presence of iodide-ions, suppressing silver extraction. Remaining impurity elements in the refined product are determined γ-spectrometrically. The method allows to determine 34 impurities with determination limits 10 -6 -10 -11 g

Process for producing high purity isoolefins and dimers thereof by dissociation of ethers

Science.gov (United States)

Smith, L.A. Jr.; Jones, E.M. Jr.; Hearn, D.

1984-05-08

Alkyl tertiary butyl ether or alkyl tertiary amyl ether is dissociated by vapor phase contact with a cation acidic exchange resin at temperatures in the range of 150 to 250 F at LHSV of 0.1 to 20 to produce a stream consisting of unreacted ether, isobutene or isoamylene and an alcohol corresponding to the alkyl radical. After the alcohol is removed, the ether/isoolefin stream may be fractionated to obtain a high purity isoolefin (99+%) or the ether/isoolefin stream can be contacted in liquid phase with a cation acidic exchange resin to selectively dimerize the isoolefin in a highly exothermic reaction, followed by fractionation of the dimerization product to produce high purity diisoolefin (97+%). In the case where the alkyl is C[sub 3] to C[sub 6] and the corresponding alcohol is produced on dissociation of the ether, combined dissociation-distillation may be carried out such that isoolefin is the overhead product and alcohol the bottom. 2 figs.

Efficiency of alfalfa seed processing with different seed purity

OpenAIRE

Đokić, Dragoslav; Stanisavljević, Rade; Terzić, Dragan; Milenković, Jasmina; Radivojević, Gordana; Koprivica, Ranko; Štrbanović, Ratibor

2015-01-01

The work was carried out analysis of the impact of the initial purity of raw alfalfa seed on the resulting amount of processed seed in the processing. Alfalfa is very important perennial forage legume which is used for fodder and seed production. Alfalfa seed is possible to achieve high yields and very good financial effects. To obtain the seed material with good characteristics complex machines for cleaning and sorting seeds are used. In the processing center of the Institute for forage crop...

Supply-side response to declining heroin purity: fentanyl overdose episode in New Jersey.

Science.gov (United States)

Hempstead, Katherine; Yildirim, Emel O

2014-06-01

The inelastic price demand observations characteristic of illegal drug markets have led to the conclusion that the burden of a negative supply shock would be completely reflected to consumers. This paper argues that the increasing availability of prescription opioids may threaten heroin sellers' profit margin and force them to find alternative methods to compensate buyers in the event of a supply shock. We investigate the 2006 fentanyl overdose episode in New Jersey and argue that the introduction of non-pharmaceutical fentanyl, its spatial distribution, and the timing of overdose deaths may have been related to trends in heroin purity. Using medical examiner data, as well as data from the Drug Enforcement Administration, Office of Diversion Control on retail sales of prescription opioids in a negative binomial specification, we show that month-to-month fluctuations in heroin purity have a significant effect on fentanyl-related overdoses, particularly in those areas where prescription opioids are highly available. Copyright © 2013 John Wiley & Sons, Ltd.

A green preparation of Mn-based product with high purity from low-grade rhodochrosite

Science.gov (United States)

Lian, F.; Ma, L.; Chenli, Z.; Mao, L.

2018-01-01

The low-grade rhodochrosite, the main resources for exploitation and applications in China, contains multiple elements such as iron, silicon, calcium and magnesium. So the conventional preparation of manganese sulphate and manganese oxide with high purity from electrolytic product is characterized by long production-cycle, high-resource input and high-pollution discharge. In our work, a sustainable preparation approach of high pure MnSO4 solution and Mn3O4 was studied by employing low-grade rhodochrosite (13.86%) as raw material. The repeated leaching of rhodochrosite with sulphuric acid was proposed in view of the same ion effect, in order to improve the solubility of Mn2+ and inhibit the dissolution of the impurities Ca2+ and Mg2+. With the aid of theoretical calculation, BaF2 was chosen to remove Ca2+ and Mg2+ completely in the process of purifying. The results showed that the impurities such as Ca2+, Mg2+, Na+ were decreased to less than 20ppm, and the Ni- and Fe- impurities were decreased to less than 1ppm, which meets the standards of high pure reagent for energy and electronic materials. The extraction ratio and the recovery ratio of manganese reached 94.3% and 92.7%, respectively. Moreover, the high pure Mn3O4 was one-step synthesized via the oxidation of MnSO4 solution with the ratios of OH-/Mn2+=2 and Mn2+/H2O2=1.03, and the recovery rate of manganese reaches 99%.

Determination of continuous variable entanglement by purity measurements.

Science.gov (United States)

Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

2004-02-27

We classify the entanglement of two-mode Gaussian states according to their degree of total and partial mixedness. We derive exact bounds that determine maximally and minimally entangled states for fixed global and marginal purities. This characterization allows for an experimentally reliable estimate of continuous variable entanglement based on measurements of purity.

Gravimetric and volumetric determination of the purity of electrolytically refined silver and the produced silver nitrate

Directory of Open Access Journals (Sweden)

Ačanski Marijana M.

2007-01-01

Full Text Available Silver is, along with gold and the platinum-group metals, one of the so called precious metals. Because of its comparative scarcity, brilliant white color, malleability and resistance to atmospheric oxidation, silver has been used in the manufacture of coins and jewelry for a long time. Silver has the highest known electrical and thermal conductivity of all metals and is used in fabricating printed electrical circuits, and also as a coating for electronic conductors. It is also alloyed with other elements such as nickel or palladium for use in electrical contacts. The most useful silver salt is silver nitrate, a caustic chemical reagent, significant as an antiseptic and as a reagent in analytical chemistry. Pure silver nitrate is an intermediate in the industrial preparation of other silver salts, including the colloidal silver compounds used in medicine and the silver halides incorporated into photographic emulsions. Silver halides become increasingly insoluble in the series: AgCl, AgBr, AgI. All silver salts are sensitive to light and are used in photographic coatings on film and paper. The ZORKA-PHARMA company (Sabac, Serbia specializes in the production of pharmaceutical remedies and lab chemicals. One of its products is chemical silver nitrate (argentum-nitricum (l. Silver nitrate is generally produced by dissolving pure electrolytically refined silver in hot 48% nitric acid. Since the purity of silver nitrate, produced in 2002, was not in compliance with the p.a. level of purity, there was doubt that the electrolytically refined silver was pure. The aim of this research was the gravimetric and volumetric determination of the purity of electrolytically refined silver and silver nitrate, produced industrially and in a laboratory. The purity determination was carried out gravimetrically, by the sedimentation of silver(I ions in the form of insoluble silver salts: AgCl, AgBr and Agi, and volumetrically, according to Mohr and Volhardt. The

Large-scale purification of {sup 90}Sr from nuclear waste materials for production of {sup 90}Y, a therapeutic medical radioisotope

Energy Technology Data Exchange (ETDEWEB)

Wester, D.W.; Steele, R.T.; Rinehart, D.E.; DesChane, J.R.; Carson, K.J.; Rapko, B.M.; Tenforde, T.S. E-mail: tenforde@ncrp.com

2003-07-01

A major limitation on the supply of the short-lived medical isotope {sup 90}Y (t{sub 1/2}=64 h) is the available quantity of highly purified {sup 90}Sr generator material. A radiochemical production campaign was therefore undertaken to purify 1500 Ci of {sup 90}Sr that had been isolated from fission waste materials. A series of alkaline precipitation steps removed all detectable traces of {sup 137}Cs, alpha emitters, and uranium and transuranic elements. Technical obstacles such as the buildup of gas pressure generated upon mixing large quantities of acid with solid {sup 90}Sr carbonate were overcome through safety features incorporated into the custom-built equipment used for {sup 90}Sr purification. Methods are described for analyzing the chemical and radiochemical purity of the final product and for accurately determining by gravimetry the quantities of {sup 90}Sr immobilized on stainless steel filters for future use.

Steam purity in PWRs

International Nuclear Information System (INIS)

Hopkinson, J.; Passell, T.

1982-01-01

Reports that 2 EPRI studies of PWRs prove that impure steam triggers decay of turbine metals. Reveals that EPRI is attempting to improve steam monitoring and analysis, which are key steps on the way to deciding the most cost-effective degree of steam purity, and to upgrade demineralizing systems, which can then reliably maintain that degree of purity. Points out that 90% of all cracks in turbine disks have occurred at the dry-to-wet transition zone, dubbed the Wilson line. Explains that because even very clean water contains traces of chemical impurities with concentrations in the parts-per-billion range, Crystal River-3's secondary loop was designed with even more purification capability; a deaerator to remove oxygen and prevent oxidation of system metals, and full-flow resin beds to demineralize 100% of the secondary-loop water from the condenser. Concludes that focusing attention on steam and water chemistry can ward off cracking and sludge problems caused by corrosion

High-Purity Glasses Based on Arsenic Chalcogenides

Science.gov (United States)

2001-06-01

Chemical interaction of chalcogenides and some impurities (CS 2, TeO2 ) with the quartz glass at high temperature leads to the thin layers formation...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1523 TITLE: High-Purity Glasses Based on Arsenic Chalcogenides...Materials Vol. 3, No. 2, June 2001, p. 341 - 349 HIGH-PURITY GLASSES BASED ON ARSENIC CHALCOGENIDES M. F. Churbanov, I. V. Scripachev, G. E. Snopatin, V. S

Linacs for medical isotope production

International Nuclear Information System (INIS)

Pramudita, A.

2012-01-01

This paper reviews efforts on using high energy (25-30 MeV) and high power (10-20 kW) electron linacs and lower energy (7 MeV) proton linacs for medical radioisotope production. Using high energy x-rays from the electron linacs, PET (Positron Emission Tomography) radioisotopes are produced through photonuclear reactions such as 19 F(γ,n) 18 F, which also allow production of other PET radionuclides 11 C, 13 N, and 15 O. Other mostly used medical radionuclides 99m Tc can also be obtained by using the electron linacs, through photofission or photonuclear reactions. Proton linacs for PET have also been recently developed and the product has been available in the market since 2005. The linacs have been tested for 18 F production. As a proton accelerator, the target systems and nuclear reactions are similar to the ones used in PET cyclotrons. (author)

Decontamination of the activation product based on a legal revision of the cyclotron vault room on the non-self-shield compact medical cyclotron

International Nuclear Information System (INIS)

Komiya, Isao; Umezu, Yoshiyuki; Fujibuchi, Toshiou; Nakamura, Kazumasa; Baba, Shingo; Honda, Hiroshi

2016-01-01

The non-self-shield compact medical cyclotron and the cyclotron vault room were in operation for 27 years. They have now been decommissioned. We efficiently implemented a technique to identify an activation product in the cyclotron vault room. Firstly, the distribution of radioactive concentrations in the concrete of the cyclotron vault room was estimated by calculation from the record of the cyclotron operation. Secondly, the comparison of calculated results with an actual measurement was performed using a NaI scintillation survey meter and a high-purity germanium detector. The calculated values were overestimated as compared to the values measured using the Nal scintillation survey meter and the high-purity germanium detector. However, it could limit the decontamination area. By simulating the activation range, we were able to minimize the concrete core sampling. Finally, the appropriate range of radioactivated area in the cyclotron vault room was decontaminated based on the results of the calculation. After decontamination, the radioactive concentration was below the detection limit value in all areas inside the cyclotron vault room. By these procedures, the decommissioning process of the cyclotron vault room was more efficiently performed. (author)

The production of radioisotopes for medical applications by the adiabatic resonance crossing (ARC) technique

CERN Document Server

Froment, P; Delbar, T; Ryckewaert, G; Tilquin, I; Vervier, J

2002-01-01

The Transmutation by Adiabatic Resonance Crossing (TARC) technique has been proposed by Rubbia (Resonance enhanced neutron captures for element activation and waste transmutation, CERN-LHC/97-0040EET, 1997; TARC collaboration, Neutron-driven nuclear transmutation by adiabatic resonance crossing, CERN-SL-99-036EET, 1999; Abanades et al., Nucl. Instr. and Meth. A 487 (2002) 577) for element activation and waste transmutation. We investigate the possibility to use this technique for the industrial production of **9**9Mo and **1**2**5Xe by resonance neutron capture in **9**8Mo and **1**2**4Xe, respectively. Their daughters, i.e. **9**9**mTc and **1**2**5I, are widely used in medical applications. The high neutron flux needed is produced by bombarding a thick Be target with 65 or 75 MeV proton beam (few microamperes). This target is placed at the centre of a large cubic lead assembly (1.6 m side, purity: 99.999%). The neutrons are progressively slowed down by elastic scattering on lead, and their energies "scan" t...

Preparation of high-purity cerium nitrate

International Nuclear Information System (INIS)

Avila, Daniela Moraes; Silva Queiroz, Carlos Alberto da; Santos Mucillo, Eliana Navarro dos

1995-01-01

The preparation of high-purity cerium nitrate has been carried out Cerium oxide has been prepared by fractioned precipitation and ionic exchange techniques, using a concentrate with approximately 85% of cerium oxide from NUCLEMON as raw material. Five sequential ion-exchange columns with a retention capacity of 170 g each have been used. The ethylenediamine-tetraacetic acid (EDTA) was used as eluent. The cerium content has been determined by gravimetry and iodometry techniques. The resulting cerium oxide has a purity > 99%. This material was transformed in cerium nitrate to be used as precursor for the preparation of Zirconia-ceria ceramics by the coprecipitation technique. (author)

Fabrication of novel cryomill for synthesis of high purity metallic nanoparticles

Science.gov (United States)

Kumar, Nirmal; Biswas, Krishanu

2015-08-01

The successful preparation of free standing metal nanoparticles with high purity in bulk quantity is the pre-requisite for any potential application. This is possible by using ball milling at cryogenic temperature. However, the most of ball mills available in the market do not allow preparing high purity metal nanoparticles by this route. In addition, it is not possible to carry out in situ measurements of process parameters as well as diagnostic of the process. In the present investigation, we present a detailed study on the fabrication of a cryomill, which is capable of avoiding contaminations in the product. It also provides in situ measurements and diagnostic of the low temperature milling process. Online monitoring of the milling temperature and observation of ball motion are the important aspects in the newly designed mill. The nanoparticles prepared using this fabricated mill have been found to be free standing and also free from contaminations.

Effect of phosphorus on hot ductility of high purity iron

International Nuclear Information System (INIS)

Abiko, K.; Liu, C.M.; Ichikawa, M..; Suenaga, H.; Tanino, M.

1995-01-01

Tensile tests on high purity Fe-P alloys with 0, 0.05 and 0.1 mass%P were carried out at temperatures between 300 K and 1073 K to clarify the intrinsic effect of phosphorus on the mechanical properties of iron at elevated temperatures. Microstructures of as-quenched, interrupted and ruptured specimens were observed. Experimental results show that the addition of phosphorus causes a remarkable increase in proof stress of high purity iron at 300 K, but the increase in proof stress by phosphorus decreases with increasing test temperature. The strengthening effect of phosphorus reduces to zero at 1073 K. High purity iron and Fe-P alloys rupture at almost 100% reduction in area at the whole test temperatures. However, Fe-P alloys show much larger elongation at test temperatures above 773 K than high purity iron. The increased elongation of high purity iron by addition of phosphorus was shown to be related to the effect of phosphorus on dynamic recovery and recrystallization of iron as its intrinsic effect. (orig.)

Medication of Production Animals – Cure of Malfunctioning Animals or Production Systems?

Directory of Open Access Journals (Sweden)

Chrièl Mariann

2003-03-01

Full Text Available Medication is used in all intensive animal productions. However, the increasing problems with resistant bacteria in all animal productions and in humans are supported by a number of reports. Special attention is given to the risk for transmitting food-borne (multi resistant zoonotic agents to humans due to failure in antibiotic treatment resulting in lower cure rates or higher case fatality rates. The use of medication in humans per se is capable of selecting for resistance in human pathogens. Nevertheless, the amount of used medication/antimicrobials in treatment of Danish production animals goes far beyond the amount used for human consumption. The increase in consumption has not been followed by a similarly increased mortality, e.g. illustrated by the number of rendered animals, increased use of injection medicine for veterinary treatments of diseased animals, or increased number of remarks on the carcasses from the slaughterhouses. Medication in animal production is facing its limits and relevant economic alternatives have to be developed. The strategy for the future must concentrate on using medication only for clinically diseased animals and not as a strategic treatment of the whole herd in order to maximise growth and camouflage of suboptimal production systems and insufficient management.

Thermal and electrical conductivities of high purity tantalum

International Nuclear Information System (INIS)

Archer, S.L.

1978-01-01

The electrical resistivity and thermal conductivity of three high purity tantalum samples have been measured as functions of temperature over a temperature range of 5K to 65K. Sample purities ranged up to a resistivity ratio of 1714. The highest purity sample had a residual resistivity of .76 x 10 -10 OMEGA-m. The intrinsic resistivity varied as T 3 . 9 from 10K to 31K. The thermal conductivity of the purest sample had a maximum of 840 W/mK at 9.8K. The intrinsic thermal resistivity varied as T 2 . 4 from 10K to 35K. At low temperatures electrons were scattered primarily by impurities and by phonons with both interband and intraband transitions observed. The electrical and thermal resistivity is departed from Matthiessen's rule at low temperatures

Obtention of high purity silica from the flotation waste of itabiritic ore

International Nuclear Information System (INIS)

Martins, Polyana Fabricia Fernandes

2016-01-01

Banded iron formations are exploited as iron mineral in 'Quadrilatero Ferrifero' of Minas Gerais (MG) State, Brazil. About half of the amount of extracted material becomes tailings, which are stored in tailing dams or used for filling mining pits. Tens of thousands of tons are generated daily in operating mines in this region, causing concern about the environmental liabilities, and costs to manage the tailing dams. Miners are committed to finding uses for these wastes in other productive chains. This thesis aimed to obtain high purity silica from the flotation tailings of banded iron formations using classical techniques for ore processing, such as particle size classification and magnetic separation, followed by hydrometallurgical leaching, also alkaline fusion and chemical precipitation. The tailings samples was collected in the tailings dam of Peak Mine operated by Vale A.S., in Itabirito – MG. This sample had initially 33.4% by weight SiO 2 , 57.4% wt Fe 2 O 3 and 8.31% wt Al 2 O 3 . After desliming for disposal of the fine particles (-37μm) the composition was 68.0% SiO 2 , 31.4% Fe 2 O 3 and 0.50% Al 2 O 3 . After magnetic separation, the composition was 93.8% SiO 2 , 1.16% Fe 2 O 3 and 3.80% Al 2 O 3 . After acid leaching l or digestion to remove impurities, it was possible to obtain silica with 98% purity. The fusion with sodium hydroxide, followed by alkaline leaching of sodium silicate and silica precipitation gave purities of about 99.5%. Values even higher may be possible with optimization of the parameters of alkaline fusion or by repeating the process from the product with purity of 99.5%. The iron oxide content and the aluminum main contaminants were 0.01% and 0.07%, respectively. Amorphous silica was obtained with high specific surface (322 m 2 /g) and particle size less than 200 nm. Depending on the application, a control should be made for the impurities, such as phosphorus, potassium and boron. (author)

Fabrication of high quality anodic aluminum oxide (AAO) on low purity aluminum—A comparative study with the AAO produced on high purity aluminum

International Nuclear Information System (INIS)

Michalska-Domańska, Marta; Norek, Małgorzata; Stępniowski, Wojciech J.; Budner, Bogusław

2013-01-01

Highlights: • Nanoporous alumina was fabricated by anodization in sulfuric acid solution with glycol. • The AAO manufacturing on low- and high-purity Al was compared. • The pores size was ranging between 30 and 50 nm. • No difference in the quality of the AAO fabricated on both Al types was observed. • The current vs. anodization time curves were recorded. -- Abstract: In this work the quality, arrangement, composition, and regularity of nanoporous AAO formed on the low-purity (AA1050) and high-purity aluminum during two-step anodization in a mixture of sulfuric acid solution (0.3 M), water and glycol (3:2, v/v), at various voltages (15, 20, 25, 30, 35 V) and at temperature of −1 °C, are investigated. The electrochemical conditions have allowed to obtain pores with the size ranging from 30 to 50 nm, which are much larger than those usually obtained by anodization in a pure sulfuric acid solution (<20 nm). The mechanism of the AAO growth is discussed. It was found that with the increase of applied anodizing voltage a number of incorporated sulfate ions in the aluminum oxide matrix increases, which was connected with the appearance of an unusual area in the current vs. time curves. On the surface of anodizing low- and high-purity aluminum, the formation of hillocks was observed, which was associated with the sulfate ions incorporation. The sulfate ions are replacing the oxygen atom/atoms in the AAO amorphous crystal structure and, consequently, the AAO template swells, the oxide cracks and uplifts causing the formation of hillocks. The same mechanism occurs for both low- and high-purity aluminum. Nanoporous AAO characterized by a very high regularity, not registered previously for low purity aluminum, was obtained. Furthermore, no significant difference in the regularity ratio between the AAO obtained on low- and high-purity aluminum, was observed. The electrochemical conditions applied in this study can be, thus, used for the fabrication of high quality

Radioactive preparations. Determination of radiochemical purity by thin-layer chromatography

International Nuclear Information System (INIS)

1986-01-01

The standard sets the data which must be attached to every sample, and the equipment, chemicals and auxiliary substances used in the determination of radiochemical purity of substances by chromatography. Described are preparation of the sample, the procedure of sample deposition, the development, drying and detection of the radioactive preparation. The qualitative and quantitative assessment of the radiochromatogram is described as are the calculation of radiochemical purity and the determination of the reproducibility of measurement of radiochemical purity of radioactive preparations. (E.S.)

Neutron activation analysis of high purity substances

International Nuclear Information System (INIS)

Gil'bert, Eh.N.

1987-01-01

Peculiarities of neutron-activation analysis (NAA) of high purity substances are considered. Simultaneous determination of a wide series of elements, high sensitivity (the lower bound of determined contents 10 -9 -10 -10 %), high selectivity and accuracy (Sr=0.10-0.15, and may be decreased up to 0.001), possibility of analysis of the samples from several micrograms to hundreds of grams, simplicity of calibration may be thought NAA advantages. Questions of accounting of NAA systematic errors associated with the neutron flux screening by the analysed matrix and with production of radionuclides of determined elements from accompanying elements according to concurrent nuclear reactions, as well as accounting of errors due to self-absorption of recorded radiation by compact samples, are considered

In-house cyclotron production of high-purity Tc-99m and Tc-99m radiopharmaceuticals.

Science.gov (United States)

Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Zagni, Federico; Corazza, Andrea; Uccelli, Licia; Pasquali, Micòl; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Skliarova, Hanna; Mou, Liliana; Cisternino, Sara; Carturan, Sara; Melendez-Alafort, Laura; Uzunov, Nikolay M; Bello, Michele; Alvarez, Carlos Rossi; Esposito, Juan; Duatti, Adriano

2018-05-30

In the last years, the technology for producing the important medical radionuclide technetium-99m by cyclotrons has become sufficiently mature to justify its introduction as an alternative source of the starting precursor [ 99m Tc][TcO 4 ] - ubiquitously employed for the production of 99m Tc-radiopharmaceuticals in hospitals. These technologies make use almost exclusively of the nuclear reaction 100 Mo(p,2n) 99m Tc that allows direct production of Tc-99m. In this study, it is conjectured that this alternative production route will not replace the current supply chain based on the distribution of 99 Mo/ 99m Tc generators, but could become a convenient emergency source of Tc-99m only for in-house hospitals equipped with a conventional, low-energy, medical cyclotron. On this ground, an outline of the essential steps that should be implemented for setting up a hospital radiopharmacy aimed at the occasional production of Tc-99m by a small cyclotron is discussed. These include (1) target production, (2) irradiation conditions, (3) separation/purification procedures, (4) terminal sterilization, (5) quality control, and (6) Mo-100 recovery. To address these issues, a comprehensive technology for cyclotron-production of Tc-99m, developed at the Legnaro National Laboratories of the Italian National Institute of Nuclear Physics (LNL-INFN), will be used as a reference example. Copyright © 2018 Elsevier Ltd. All rights reserved.

Purity of Gaussian states: Measurement schemes and time evolution in noisy channels

International Nuclear Information System (INIS)

Paris, Matteo G.A.; Illuminati, Fabrizio; Serafini, Alessio; De Siena, Silvio

2003-01-01

We present a systematic study of the purity for Gaussian states of single-mode continuous variable systems. We prove the connection of purity to observable quantities for these states, and show that the joint measurement of two conjugate quadratures is necessary and sufficient to determine the purity at any time. The statistical reliability and the range of applicability of the proposed measurement scheme are tested by means of Monte Carlo simulated experiments. We then consider the dynamics of purity in noisy channels. We derive an evolution equation for the purity of general Gaussian states both in thermal and in squeezed thermal baths. We show that purity is maximized at any given time for an initial coherent state evolving in a thermal bath, or for an initial squeezed state evolving in a squeezed thermal bath whose asymptotic squeezing is orthogonal to that of the input state

Uranium refining in South Africa. The production of uranium trioxide, considering raw material properties and nuclear purity requirements

International Nuclear Information System (INIS)

Colborn, R.P.; Bayne, D.L.G.; Slabber, M.N.

1980-01-01

Conventional practice results in raw materials being delivered to the uranium refineries in a form more suitable for transportation than for processing, and therefore the refineries are required to treat these raw materials to produce an acceptable intermediate feed stock. During this treatment, it is advantageous to include a purification step to ensure that the feed stock is of the required purity for nuclear grade uranium hexafluoride production, and this usually results in ammonium diuranate slurries of the required quality being produced as the intermediate feed stock. All subsequent processing steps can therefore be standardized and are effectively independent of the origin of the raw materials. It is established practice in South Africa to transport uranium as an ammonium diuranate slurry from the various mines to the Nufcor central processing plant for UOC production, and therefore the process for the production of uranium hexafluoride in South Africa was designed to take cognizance of existing transport techniques and to accept ammonium diuranate slurries as the raw material. The South African refinery will be able to process these slurries directly to uranium trioxide. This paper discusses the conditions under which the various ammonium diuranate raw materials, exhibiting a wide range of properties, can be effectively processed to produce a uranium trioxide of acceptably consistent properties. Mention is also made of the uranium hexafluoride distillation process adopted

7 CFR 201.51b - Purity procedures for coated seed.

Science.gov (United States)

2010-01-01

... ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.51b Purity...). Use of fine mesh sieves is recommended for this procedure, and stirring or shaking the coated units...

Radiation sterilization of some pharmaceutical preparations and medical products

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Makhkamov, Sh.M.; Urinov, Sh.S.; Turaev, A.S.; Sultanov, M.S.; Inagomov, Kh.S.

2006-01-01

Full text: In connection with intensive development of pharmacology and medical techniques, use of the products contacting to blood, with the internal environment of an organism, with wound surface, with mucous membranes and skin there were high requirements to sterility of pharmaceutical preparations and medical products. Traditional methods of sterilization (heat treatment, gas processing and processing the ferry) have some restrictions in application, and not insufficient degree of sterilization required for pharmaceutical preparations and medical products. Thermal processing can lead to degradation of structure (medicine), mechanical changes and loss of medical properties. Besides, it is impossible to carry out sterilization of many pharmaceutical preparations by a method of heat treatment. Sterilization of products in packing is very complicated, because sterilization temperature of packing and a product is different. Gas processing is basically applied to sterilization of medical products (syringes, bandage, cotton wools, etc.). However, the degree of sterility is low, because of rather low ability and heterogeneity of sterilizing substance. Sterilization in packing represents special difficulty and demands additional charges related with delivery of the purified gas from abroad. Last years alongside with known technological methods of sterilization of medical products and pharmaceutical preparations radiating methods of processing have found wide application. Use of electronic bunches with the moderate energy and various isotopes became a basis for formation and development of a new direction in the medicine, called by 'radiation sterilization'. The radiation technology is highly harmless and economic, not polluting substance and surrounding space. Unlike the specified traditional methods, radiating processing of products by the isotope 60 Co, radiating the gamma quantum, has unique opportunities - high penetrability in substance, providing uniformity of

The effect of foil purity on morphology of anodized nanoporous ZrO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Wierzbicka, Ewa; Syrek, Karolina [Department of Physical Chemistry & Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Ingardena 3, 30-060 Krakow (Poland); Sulka, Grzegorz D., E-mail: sulka@chemia.uj.edu.pl [Department of Physical Chemistry & Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Ingardena 3, 30-060 Krakow (Poland); Pisarek, Marcin; Janik-Czachor, Maria [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)

2016-12-01

Highlights: • Anodization of Zr with different purities in an aqueous electrolyte was studied. • The structural parameters of formed anodic oxides were compared. • Effect of Zr foil purity on the hexagonal arrangement of pores and cells in anodic ZrO{sub 2} was investigated. • Current efficiency and rate of anodic oxide formation were estimated. - Abstract: A two-step electrochemical formation of nanoporous zirconium oxide layers on different zirconium foils (purity 99.2% and 99.8%) was investigated. Anodizations were carried out at 20 V in an electrolyte composed of 1 M (NH{sub 4}){sub 2}SO{sub 4} and 0.15 M NH{sub 4}F. It was found that the thickness of grown oxide layer, and consequently, the rate of oxide formation depend slightly on the Zr substrate purity. The pore nucleation and anodization process occur easier in the presence of higher concentration of impurities. From top view SEM images, the structural parameters of oxide layers such as pore diameter, interpore distance, pore density, wall thickness and porosity of anodic oxide layers were estimated for both types of used substrates. On the other hand, cell size, intercell distance and cell density were evaluated from the bottom side of anodic oxide layers. A special emphasis was put on the qualitative analysis of hexagonal arrangement of nanopores and cells. The nanopore and cells arrangements in formed oxides were evaluated using various approaches based on Delaunay triangulations, angular distribution functions (ADFs) and pair distribution functions (PDFs). These results were supported by calculations of percentage of defective pores and cells for both types of used Zr substrates. The use of low purity Zr for anodizing does not affect drastically the morphology of formed nanoporous zirconia and offers a promising perspective to reduce production costs and increase availability of this material.

The Liquid Argon Purity Demonstrator

Energy Technology Data Exchange (ETDEWEB)

Adamowski, M.; Carls, B.; Dvorak, E.; Hahn, A.; Jaskierny, W.; Johnson, C.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Stancari, M.; Tope, T.; Voirin, E.; Yang, T.

2014-07-01

The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

Firewalls from double purity

Science.gov (United States)

Bousso, Raphael

2013-10-01

The firewall paradox is often presented as arising from double entanglement, but I argue that more generally the paradox is double purity. Near-horizon modes are purified by the interior, in the infalling vacuum. Hence, they cannot also be pure alone, or in combination with any third system, as demanded by unitarity. This conflict arises independently of the Page time, for entangled and for pure states. It implies that identifications of Hilbert spaces cannot resolve the paradox. Traditional complementarity requires the unitary identification of infalling matter with a scrambled subsystem of the Hawking radiation. Extending this map to the infalling vacuum overdetermines the out-state. More general complementarity maps (“A=RB,” “ER=EPR”) necessarily fail when the near-horizon zone is pure. I argue that pure-zone states span the microcanonical ensemble, and that this suffices to make the horizon a special place. I advocate that the ability to detect the horizon locally, rather than the degree or probability of violence, is what makes firewalls problematic. Conversely, if the production of matter at the horizon can be dynamically understood and shown to be consistent, then firewalls do not constitute a violation of the equivalence principle.

Purity and adulterant analysis of crack seizures in Brazil.

Science.gov (United States)

Fukushima, André R; Carvalho, Virginia M; Carvalho, Débora G; Diaz, Ernesto; Bustillos, Jose Oscar William Vega; Spinosa, Helenice de S; Chasin, Alice A M

2014-10-01

Cocaine represents a serious problem to society. Smoked cocaine is very addictive and it is frequently associated with violence and health issues. Knowledge of the purity and adulterants present in seized cocaine, as well as variations in drug characteristics are useful to identify drug source and estimate health impact. No data are available regarding smoked cocaine composition in most countries, and the smoked form is increasing in the Brazilian market. The purpose of the present study is to contribute to the current knowledge on the status of crack cocaine seized samples on the illicit market by the police of São Paulo. Thus, 404 samples obtained from street seizures conducted by the police were examined. The specimens were macroscopically characterized by color, form, odor, purity, and adulterant type, as well as smoke composition. Samples were screened for cocaine using modified Scott test and thin-layer chromatographic (TLC) technique. Analyses of purity and adulterants were performed with gas chromatography equipped with flame ionization detector (GC-FID). Additionally, smoke composition was analyzed by GC-mass spectrometry (MS), after samples burning. Samples showed different colors and forms, the majority of which is yellow (74.0%) or white (20.0%). Samples free of adulterants represented 76.3% of the total. Mean purity of the analyzed drug was 71.3%. Crack cocaine presented no correlations between macroscopic characteristics and purity. Smoke analysis showed compounds found also in the degradation of diesel and gasoline. Therefore, the drug marketed as crack cocaine in São Paulo has similar characteristics to coca paste. High purity can represent a greater risk of dependency and smoke compounds are possibly worsening drug health impact. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Lying and the Subsequent Desire for Toothpaste: Activity in the Somatosensory Cortex Predicts Embodiment of the Moral-Purity Metaphor.

Science.gov (United States)

Denke, Claudia; Rotte, Michael; Heinze, Hans-Jochen; Schaefer, Michael

2016-02-01

It is well known from literature and religious ceremonies that there is a link between physical cleansing and moral transgressions. Only recently, psychological experiments explored this association and demonstrated that a threat to moral purity increases the demand of physical cleansing. Moreover, it has been shown that physical cleansing is actually efficacious to cope with threatened morality. This so-called Macbeth effect has been explained by an embodiment of the moral-purity metaphor. We tested this hypothesis by means of an functional magnetic resonsce imaging (fMRI) experiment. Participants were instructed to enact scenarios including either an immoral act (lying) or a moral deed (telling the truth). Subsequently, the participants were asked to rate the desirableness of various products. Results revealed that participants rated cleansing products (but not other goods) more desirable after performing an immoral than after a moral act. This Macbeth effect was accompanied by an active cortical network including sensorimotor brain areas during rating of cleansing products (but not while evaluating noncleansing goods). The results demonstrate neurobiological evidence for an embodiment of the moral-purity metaphor. Thus, abstract thoughts about morality can be grounded in sensory experiences. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Purity Evaluation of Single-Walled Carbon Nanotubes Using Thermogravimetric Analysis

International Nuclear Information System (INIS)

Goak, Jeung Choon; Kim, Tae Yang; Jung, Jongwan; Seo, Young-Soo; Lee, Naesung; Sok, Junghyun

2013-01-01

This study evaluated the purity of single-walled carbon nanotubes (SWCNTs) in the arc-synthesized SWCNT samples by using thermogravimetric analysis (TGA). The as-produced SWCNT samples were heat-treated in air for 20 h at 275-475°C and characterized by scanning and transmission electron microscopes and TGA to establish oxidation temperature ranges of SWCNTs and carbonaceous impurities comprising the samples. Based on these oxidation temperature ranges, derivative thermogravimetric curves were deconvoluted, and differentiated peaks were assigned to SWCNTs and carbonaceous impurities. The compositions and the SWCNT purities of the samples were obtained simply by calculating the areal ratios under the deconvoluted curves. TGA studies on purity evaluation and thermal stabilities of SWCNTs and carbonaceous impurities are likely to provide us with a simple route of thermal oxidation purification to acquire high-purity SWCNT samples.

Human parvovirus B19 infection in hemophiliacs first infused with two high-purity, virally attenuated factor VIII concentrates.

Science.gov (United States)

Azzi, A; Ciappi, S; Zakvrzewska, K; Morfini, M; Mariani, G; Mannucci, P M

1992-03-01

Human parvovirus B19 can be transmitted by coagulation factor concentrates and is highly resistant to virucidal methods. To evaluate whether the additional removal of virus by chromatographic methods during the manufacture of high-purity concentrates reduces the risk of B19 transmission, we have prospectively evaluated the rate of anti-B19 seroconversion in two groups of susceptible (anti-B19 negative) hemophiliacs infused with high-purity, heated (pasteurized) or solvent-detergent-treated factor VIII concentrates. Both products infected a relatively high proportion of patients (nine of 20).

Increased production of megakaryocytes near purity from cord blood CD34+ cells using a short two-phase culture system.

Science.gov (United States)

Boyer, Lucie; Robert, Amélie; Proulx, Chantal; Pineault, Nicolas

2008-03-20

Expansion of hematopoietic progenitor cells (HPC) ex vivo remains an important focus in fundamental and clinical research. The aim of this study was to determine whether the implementation of such expansion phase in a two-phase culture strategy prior to the induction of megakaryocyte (Mk) differentiation would increase the yield of Mks produced in cultures. Toward this end, we first characterized the functional properties of five cytokine cocktails to be tested in the expansion phase on the growth and differentiation kinetics of CD34+-enriched cells, and on their capacity to expand clonogenic progenitors in cultures. Three of these cocktails were chosen based on their reported ability to induce HPC expansion ex vivo, while the other two represented new cytokine combinations. These analyses revealed that none of the cocktails tested could prevent the differentiation of CD34+ cells and the rapid expansion of lineage-positive cells. Hence, we sought to determine the optimum length of time for the expansion phase that would lead to the best final Mk yields. Despite greater expansion of CD34+ cells and overall cell growth with a longer expansion phase, the optimal length for the expansion phase that provided greater Mk yield at near maximal purity was found to be 5 days. Under such settings, two functionally divergent cocktails were found to significantly increase the final yield of Mks. Surprisingly, these cocktails were either deprived of thrombopoietin or of stem cell factor, two cytokines known to favor megakaryopoiesis and HPC expansion, respectively. Based on these results, a short resource-efficient two-phase culture protocol for the production of Mks near purity (>95%) from human CD34+ CB cells has been established.

Contribution to the study of the conductivity of high purity water

International Nuclear Information System (INIS)

Nens, Ch.

1964-01-01

In this work a study is made more particularly of two points: the production of high purity water and the estimation of this purity by means of conductivity measurements. As far as water purification is concerned it is observed that the de-ionisation produced by ion exchange resins in mixed beds leads to a water having a lower conductivity than that obtained by distillation. This low conductivity however, measured at the column exit before the water comes into contact with air is not stable. In fact the carbon dioxide in the water gives rise to an equilibrium with production of the ions HCO 3 - , CO 3 -- . These ions are retained during the passage of the water through the resins. They reappear again at the column exit as a result of the displacement of the hydration equilibrium of CO 2 ; because of this the conductivity of the water increases with time. The water obtained by successive distillations does not behave in the same way because no carbon dioxide is present. Distillation is however a costly purification process on an industrial scale, especially if large quantities of water have to be treated. The measurement of these low conductivities is very delicate. The method employed makes use of a direct current and gives reproducible results if care is taken to exclude interfering electric fields by screening the apparatus. (author) [fr

Iodine Absorption Cells Purity Testing

Directory of Open Access Journals (Sweden)

Jan Hrabina

2017-01-01

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

A Cultural Look at Moral Purity: Wiping the Face Clean

Directory of Open Access Journals (Sweden)

Spike W. S. eLee

2015-05-01

Full Text Available Morality is associated with bodily purity in the custom of many societies. Does that imply moral purity is a universal psychological phenomenon? Empirically, it has never been examined, as all prior experimental data came from Western samples. Theoretically, we suggest the answer is not so straightforward—it depends on the kind of universality under consideration. Combining perspectives from cultural psychology and embodiment, we predict a culture-specific form of moral purification. Specifically, given East Asians’ emphasis on the face as a representation of public self-image, we hypothesize that facial purification should have particularly potent moral effects in a face culture. Data show that face-cleaning (but not hands-cleaning reduces guilt and regret most effectively against a salient East Asian cultural background. It frees East Asians from guilt-driven prosocial behavior. In the wake of their immorality, they find a face-cleaning product especially appealing and spontaneously choose to wipe their face clean. These patterns highlight both culturally variable and universal aspects of moral purification. They further suggest an organizing principle that informs the vigorous debate between embodied and amodal perspectives.

Quantitative analyses of impurity silicon-carbide (SiC) and high-purity-titanium by neutron activation analyses based on k0-standardization method. Development of irradiation silicon technology in productivity using research reactor (Joint research)

International Nuclear Information System (INIS)

Motohashi, Jun; Takahashi, Hiroyuki; Magome, Hirokatsu; Sasajima, Fumio; Tokunaga, Okihiro; Kawasaki, Kozo; Onizawa, Koji; Isshiki, Masahiko

2009-07-01

JRR-3 and JRR-4 have been providing neutron-transmutation-doped silicon (NTD-Si) by using the silicon NTD process, which is a method to produce a high quality semiconductor. The domestic supply of NTD-Si is insufficient for the demand, and the market of NTD-Si is significantly growing at present. It is very important to increase achieve the production. To fulfill the requirement, we have been investigating a neutron filter, which is made of high-purity-titanium, for uniform doping. Silicon-carbide (SiC) semiconductor doped with NTD technology is considered suitable for high power devices with superior performances to conventional Si-based devices. We are very interested in the SiC as well. This report presents the results obtained after the impurity contents in the high-purity-titanium and SiC were analyzed by neutron activation analyses (NAA) using k 0 -standardization method. There were 6 and 9 impurity elements detected from the high-purity-titanium and SiC, respectively. Among those Sc from the high-purity-titanium and Fe from SiC were comparatively long half life nuclides. From the viewpoint of exposure in handling them, we need to examine the impurity control of materials. (author)

Superconducting radio-frequency cavities made from medium and low-purity niobium ingots

Science.gov (United States)

Ciovati, Gianluigi; Dhakal, Pashupati; Myneni, Ganapati R.

2016-06-01

Superconducting radio-frequency cavities made of ingot niobium with residual resistivity ratio (RRR) greater than 250 have proven to have similar or better performance than fine-grain Nb cavities of the same purity, after standard processing. The high purity requirement contributes to the high cost of the material. As superconducting accelerators operating in continuous-wave typically require cavities to operate at moderate accelerating gradients, using lower purity material could be advantageous not only to reduce cost but also to achieve higher Q 0-values. In this contribution we present the results from cryogenic RF tests of 1.3-1.5 GHz single-cell cavities made of ingot Nb of medium (RRR = 100-150) and low (RRR = 60) purity from different suppliers. Cavities made of medium-purity ingots routinely achieved peak surface magnetic field values greater than 70 mT with an average Q 0-value of 2 × 1010 at 2 K after standard processing treatments. The performances of cavities made of low-purity ingots were affected by significant pitting of the surface after chemical etching.

Entanglement and purity of two-mode Gaussian states in noisy channels

International Nuclear Information System (INIS)

Serafini, Alessio; Illuminati, Fabrizio; De Siena, Silvio; Paris, Matteo G.A.

2004-01-01

We study the evolution of purity, entanglement, and total correlations of general two-mode continuous variable Gaussian states in arbitrary uncorrelated Gaussian environments. The time evolution of purity, von Neumann entropy, logarithmic negativity, and mutual information is analyzed for a wide range of initial conditions. In general, we find that a local squeezing of the bath leads to a faster degradation of purity and entanglement, while it can help to preserve the mutual information between the modes

Cybersecurity and the Medical Device Product Development Lifecycle.

Science.gov (United States)

Jones, Richard W; Katzis, Konstantinos

2017-01-01

Protecting connected medical devices from evolving cyber related threats, requires a continuous lifecycle approach whereby cybersecurity is integrated within the product development lifecycle and both complements and re-enforces the safety risk management processes therein. This contribution reviews the guidance relating to medical device cybersecurity within the product development lifecycle.

Radiosterilization of medical products, pharmaceuticals and bioproducts

International Nuclear Information System (INIS)

1967-01-01

A Panel on the Radiosterilization of Medical Products, Pharmaceuticals and Bioproducts was convened by the International Atomic Energy Agency on 17-19 January 1966 at its headquarters in Vienna. The purpose of the meeting was to survey the activities of the Member States in this field with a view to preparing the way for an international code of practice for the radiosterilization of medical products, in conformity with existing legal international rules. Refs, figs and tabs

Ionizing radiation for sterilization of medical products and biological tissues

Energy Technology Data Exchange (ETDEWEB)

Kumar, S K; Raghevendrarao, M K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

1975-10-01

The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products.

Superconducting radio-frequency cavities made from medium and low-purity niobium ingots

International Nuclear Information System (INIS)

Ciovati, Gianluigi; Dhakal, Pashupati; Myneni, Ganapati R

2016-01-01

Superconducting radio-frequency cavities made of ingot niobium with residual resistivity ratio (RRR) greater than 250 have proven to have similar or better performance than fine-grain Nb cavities of the same purity, after standard processing. The high purity requirement contributes to the high cost of the material. As superconducting accelerators operating in continuous-wave typically require cavities to operate at moderate accelerating gradients, using lower purity material could be advantageous not only to reduce cost but also to achieve higher Q 0 -values. In this contribution we present the results from cryogenic RF tests of 1.3–1.5 GHz single-cell cavities made of ingot Nb of medium (RRR = 100–150) and low (RRR = 60) purity from different suppliers. Cavities made of medium-purity ingots routinely achieved peak surface magnetic field values greater than 70 mT with an average Q 0 -value of 2 × 10 10 at 2 K after standard processing treatments. The performances of cavities made of low-purity ingots were affected by significant pitting of the surface after chemical etching. (paper)

Purity and surface roughness of vacuum deposited aluminium films

Energy Technology Data Exchange (ETDEWEB)

Dhere, N G; Arsenio, T P [Instituto Militar de Engenharia, Rio de Janeiro (Brazil); Patnaik, B K [Pontificia Universidade Catolica do Rio de Janeiro (Brazil). Instituto de Fisica; Assuncao, F C.R.; de Souza, A M [Pontificia Universidade Catolica do Rio de Janeiro (Brazil). Departamento de Ciencia dos Materiais e Metalurgia

1975-04-01

The authors studied the purity, surface roughness and grain size of vacuum-deposited aluminium films, using an intermetallic crucible and a continuous feed of pure aluminium wire. The grain size and roughness were studied by electron difraction, X-ray diffraction and the scanning electron microscope. Purity was determined by X-ray fluorescence produced by proton bombardment in the Van de Graaff accelerator and by X-ray and optical emission spectrometry.

Scientific production of medical sciences universities in north of iran.

Science.gov (United States)

Siamian, Hasan; Firooz, Mousa Yamin; Vahedi, Mohammad; Aligolbandi, Kobra

2013-01-01

NONE DECLARED. The study of the scientific evidence citation production by famous databases of the world is one of the important indicators to evaluate and rank the universities. The study at investigating the scientific production of Northern Iran Medical Sciences Universities in Scopus from 2005 through 2010. This survey used scientometrics technique. The samples under studies were the scientific products of four northern Iran Medical universities. Viewpoints quantity of the Scientific Products Mazandaran University of Medical Sciences stands first and of Babol University of Medical Sciences ranks the end, but from the viewpoints of quality of scientific products of considering the H-Index and the number of cited papers the Mazandaran University of Medical Sciences is a head from the other universities under study. From the viewpoints of subject of the papers, the highest scientific products belonged to the faculty of Pharmacy affiliated to Mazandaran University of Medial Sciences, but the three other universities for the genetics and biochemistry. Results showed that the Mazandaran University of Medical Sciences as compared to the other understudies universities ranks higher for the number of articles, cited articles, number of hard work authors and H-Index of Scopus database from 2005 through 2010.

High-purity aluminium creep under high hydrostatic pressure

International Nuclear Information System (INIS)

Zajtsev, V.I.; Lyafer, E.I.; Tokij, V.V.

1977-01-01

The effect of the hydrostatic pressure on the rate of steady-state creep of high-purity aluminium was investigated. It is shown that the hydrostatic pressure inhibits the creep. The activation volume of the creep is independent of the direction in the range of (4.7-6.2) kg/mm 2 and of the pressure in the range of (1-7.8000) atm. It is concluded that self-diffusion does not control the creep of high-purity aluminium at room temperature in the investigated stress and pressure range

Purity Evaluation of Bulk Single Wall Carbon Nanotube Materials

International Nuclear Information System (INIS)

Dettlaff-Weglikowska, U.; Hornbostel, B.; Cech, J.; Roth, S.; Wang, J.; Liang, J.

2005-01-01

We report on our experience using a preliminary protocol for quality control of bulk single wall carbon nanotube (SWNT) materials produced by the electric arc-discharge and laser ablation method. The first step in the characterization of the bulk material is mechanical homogenization. Quantitative evaluation of purity has been performed using a previously reported procedure based on solution phase near-infrared spectroscopy. Our results confirm that this method is reliable in determining the nanotube content in the arc-discharge sample containing carbonaceous impurities (amorphous carbon and graphitic particles). However, the application of this method to laser ablation samples gives a relative purity value over 100 %. The possible reason for that might be different extinction coefficient meaning different oscillator strength of the laser ablation tubes. At the present time, a 100 % pure reference sample of laser ablation SWNT is not available, so we chose to adopt the sample showing the highest purity as a new reference sample for a quantitative purity evaluation of laser ablation materials. The graphitic part of the carbonaceous impurities has been estimated using X-ray diffraction of 1:1 mixture of nanotube material and C60 as an internal reference. To evaluate the metallic impurities in the as prepared and homogenized carbon nanotube soot inductive coupled plasma (ICP) has been used

Modelling of hydrogen permeability of membranes for high-purity hydrogen production

Science.gov (United States)

Zaika, Yury V.; Rodchenkova, Natalia I.

2017-11-01

High-purity hydrogen is required for clean energy and a variety of chemical technology processes. Different alloys, which may be well-suited for use in gas-separation plants, were investigated by measuring specific hydrogen permeability. One had to estimate the parameters of diffusion and sorption to numerically model the different scenarios and experimental conditions of the material usage (including extreme ones), and identify the limiting factors. This paper presents a nonlinear mathematical model taking into account the dynamics of sorption-desorption processes and reversible capture of diffusing hydrogen by inhomogeneity of the material’s structure, and also modification of the model when the transport rate is high. The results of numerical modelling allow to obtain information about output data sensitivity with respect to variations of the material’s hydrogen permeability parameters. Furthermore, it is possible to analyze the dynamics of concentrations and fluxes that cannot be measured directly. Experimental data for Ta77Nb23 and V85Ni15 alloys were used to test the model. This work is supported by the Russian Foundation for Basic Research (Project No. 15-01-00744).

Growth of high purity semiconductor epitaxial layers by liquid phase ...

Indian Academy of Sciences (India)

Unknown

semiconductor materials in high purity form by liquid phase epitaxy (LPE) technique. Various possible sources of impurities in such ... reference to the growth of GaAs layers. The technique of growing very high purity layers ... the inner walls of the gas lines and (e) the containers for storing, handling and cleaning of the mate-.

Purity and Defect Characterization of Single-Wall Carbon Nanotubes Using Raman Spectroscopy

Directory of Open Access Journals (Sweden)

Yasumitsu Miyata

2011-01-01

Full Text Available We investigated the purity and defects of single-wall carbon nanotubes (SWCNTs produced by various synthetic methods including chemical vapor deposition, arc discharge, and laser ablation. The SWCNT samples were characterized using scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and Raman spectroscopy. Quantitative analysis of SEM images suggested that the G-band Raman intensity serves as an index for the purity. By contrast, the intensity ratio of G-band to D-band (G/D ratio reflects both the purity and the defect density of SWCNTs. The combination of G-band intensity and G/D ratio is useful for a quick, nondestructive evaluation of the purity and defect density of a SWCNT sample.

Activation analysis of high purity metals and application to study on physical properties

International Nuclear Information System (INIS)

Ueda, Yoshitake; Hashimoto, Eiji; Matsushita, Rokuji.

1994-01-01

In order to determine the true characteristics of matters, the utmost reduction of impurities is indispensable. By the heightening of the purity of aluminum, that of 99.9999% purity has been obtained, but efforts have been exerted to further heighten the purity. For the purpose, it is important to know the behavior of trace impurities during refining, and the quantitative research by neutron activation analysis for various impurities has been carried out. The research on the electron condition of trace impurity atoms in refined aluminum is also important. The band refining of high purity aluminum is explained. By repeating the refining 10 times, the sample of RRR exceeding 30000 was obtained. The impurities contributing to the resistivity are Sc, Ti, V and Cr. Based on the results, the heightening of aluminum purity was attempted by devising the new procedure. As for the electric properties of solute elements in high purity metals, those of transition elements and rare earth elements in aluminum are reported. As the result of measuring the remaining resistance, the sample having the RRR exceeding 45000 after the correction for size effect was done has been obtained. At present, the efforts toward further high purity are continued. (K.I.)

On the purity assessment of solid sodium borohydride

Science.gov (United States)

Botasini, Santiago; Méndez, Eduardo

2012-01-01

Since sodium borohydride has become extensively used as chemical hydrogen storage material in fuel cells, many techniques have been proposed to assess the purity of this substance. However, all of them are developed in aqueous media, where the reagent is unstable. In addition, its hygroscopic nature was difficults in any attempt to make precise quantifications. The present work compares three different methods, namely, voltammetric, titrimetric, and Fourier transformed infrared spectroscopy (FTIR) in order to assess the purity of sodium borohydride, using an expired and a new sodium borohydride samples as references. Our results show that only the FTIR measurements provide a simple and semi-quantitative means to assess the purity of sodium borohydride due to the fact that it is the only one that measures the sample in the solid state. A comparison between the experimental data and theoretical calculation reveals the identification of the absorption bands at 1437 cm-1 of sodium metaborate and 2291 cm-1 of sodium borohydride which represent a good fingerprint for the qualitative assessment of the sample quality.

Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans.

Science.gov (United States)

Wang, Limin; Cai, Yumeng; Zhu, Lingfeng; Guo, Honglian; Yu, Bo

2014-12-01

Bacillus coagulans 2-6 is an excellent producer of optically pure l-lactic acid. However, little is known about the mechanism of synthesis of the highly optically pure l-lactic acid produced by this strain. Three enzymes responsible for lactic acid production-NAD-dependent l-lactate dehydrogenase (l-nLDH; encoded by ldhL), NAD-dependent d-lactate dehydrogenase (d-nLDH; encoded by ldhD), and glycolate oxidase (GOX)-were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid. Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (a d-lactic acid producer) and Lactobacillus plantarum subsp. plantarum DSM 20174 (a dl-lactic acid producer) were also examined in this study as comparative strains, in addition to B. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterized in vivo and in vitro, and the levels of transcription of the ldhL, ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities of l-nLDH and d-nLDH were different in l-, d-, and dl-lactic acid producers. Only l-nLDH activity was detected in B. coagulans 2-6 under native conditions, and the level of transcription of ldhL in B. coagulans 2-6 was much higher than that of ldhD or the GOX gene at all growth phases. However, for the two Lactobacillus strains used in this study, ldhD transcription levels were higher than those of ldhL. The high catalytic efficiency of l-nLDH toward pyruvate and the high transcription ratios of ldhL to ldhD and ldhL to the GOX gene provide the key explanations for the high optical purity of l-lactic acid produced by B. coagulans 2-6. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Perspectives of data-driven LPV modeling of high-purity distillation columns

NARCIS (Netherlands)

Bachnas, A.A.; Toth, R.; Mesbah, A.; Ludlage, J.H.A.

2013-01-01

Abstract—This paper investigates data-driven, Linear- Parameter-Varying (LPV) modeling of a high-purity distillation column. Two LPV modeling approaches are studied: a local approach, corresponding to the interpolation of Linear Time- Invariant (LTI) models identified at steady-state purity levels,

Recycling of high purity selenium from CIGS solar cell waste materials

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Anna M.K., E-mail: anna.gustafsson@chalmers.se; Foreman, Mark R.StJ.; Ekberg, Christian

2014-10-15

Highlights: • A new method for recycling of selenium from CIGS solar cell materials is presented. • Separation of selenium as selenium dioxide after heating in oxygen atmosphere. • Complete selenium separation after oxidation of <63 μm particles at 800 °C for 1 h. • After reduction of selenium dioxide the selenium purity was higher than 99.999 wt%. - Abstract: Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1 h at 800 °C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS.

The effect of ionizing radiation on microbiological decontamination of medical herbs and biologically active compounds

Science.gov (United States)

Migdal, W.; Owczarczyk, B.; Kedzia, B.; Holderna-Kedzia, E.; Segiet-Kujawa, E.

1998-06-01

Several thousand tons of medical herbs are produced annually by pharmaceutical industry in Poland. This product should be of highest quality and microbial purity. Recently, chemical methods of decontamination are recognized as less safe, thus irradiation technique was chosen to replace them in use. In the Institute of Nuclear Chemistry and Technology the national program on the application of irradiation to the decontamination of medical herbs is in progress now. The purpose of the program is to elaborate, on the basis of research work, the facility standards and technological instructions indispensable for the practice of radiation technology.

Determination of radiochemical purity using gas chromatography

International Nuclear Information System (INIS)

1975-01-01

The concepts of chromatography, gas chromatography, activity, radiochemical impurity are defined; the procedure of the application of gas chromatography for detecting radiochemical purity of substances is standardized. (E.F.)

A comparative study of nitride purity and Am fabrication losses in PuN materials by the powder and internal gelation production routes

Energy Technology Data Exchange (ETDEWEB)

Hedberg, Marcus, E-mail: marhed@chalmers.se; Ekberg, Christian

2016-12-15

Fabrication of plutonium containing fuels through the internal gelation method has mostly been studied in mixed metal systems such as U, Pu or Zr,Pu. In this work production of undiluted PuN has been performed by carbothermal reduction on both oxide powder and Pu microspheres produced by the internal gelation method. Nitride purities reached using the different methods have been studied together with final densities achieved during pellet fabrication as well as losses of ingrown Am during the different production steps. Formation of Pu microspheres was successfully performed using the internal gelation method, although extensive microsphere fracturing occurred during thermal treatment. Final densities of PuN pellets produced by cold pressing and sintering reached 70–80% of theoretical density. Am losses during the carbothermal reduction step was on average about 3.7%. After sintering about 11% of Am was lost in total through the entire production process if sintering in N{sub 2} + 5% H{sub 2} atmosphere while about 50% of the Am in total was lost when using Ar as sintering atmosphere. - Highlights: • Internal gelation Pu based sols was performed. • Nitride formation by carbothermal reduction on Pu microspheres and powders was performed. • Pelletization and sintering of pellets was performed. • Am losses were measured throughout the production steps.

High-purity fatty acid methyl ester production from canola, soybean, palm, and yellow grease lipids by means of a membrane reactor

International Nuclear Information System (INIS)

Cao Peigang; Dube, Marc A.; Tremblay, Andre Y.

2008-01-01

High-purity fatty acid methyl ester (FAME) was produced from different lipids, such as soybean oil, canola oil, a hydrogenated palm oil/palm oil blend, yellow grease, and brown grease, combined with methanol using a continuous membrane reactor. The membrane reactor combines reaction and separation in a single unit, provides continuous mixing of raw materials, and maintains a high molar ratio of methanol to lipid in the reaction loop while maintaining two phases during the reaction. It was demonstrated that the membrane reactor can be operated using a very broad range of feedstocks at highly similar operating conditions to produce FAME. The total glycerine and free glycerine contents of the FAME produced were below the ASTM D6751 standard after a single reaction step. Under essentially the same reaction conditions, a conventional batch reaction was not able to achieve the same degree of FAME purity. The effect of the fatty acid composition of the lipid feedstocks on the FAME purity was also shown. It was demonstrated that, due to the fatty acid composition, FAME from virgin soybean oil and virgin canola oil was produced in the membrane reactor within ASTM specifications even without a water washing step

Abridged acid-base wet-milling synthesis of high purity hydroyapatite

Directory of Open Access Journals (Sweden)

Sandi Carolina Ruiz-Mendoza

2008-06-01

Full Text Available There is a plethora of routes to produce hydroxyapatite(HA and in general calcium phosphates(CP but production usually leads to a mixture of several phases. Besides ionic contamination, most of these methods are cumbersome, restricted to small volumes of product and require a lot of thermal energy. The acid-base route eliminates foreign ions or additives and its only byproduct is water. Heterogeneous reaction drawback is that solid reactants do not easily come in contact with each other and therefore addition and stirring times become very lengthy and still the product is a mixture. The synthesis started from calcium hydroxide and phosphoric acid (PA. Ball milling was used to favor kinetics and stoichiometry. Six sets of PA addition, paddle stirring and ball milling times were used. Products were evaluated by X ray diffraction (XRD, Fourier Transform Infrared (FTIR, scanning electron microscopy (SEM, X ray fluorescence (XRF and Ca/P ratio. Chemical analysis for calcium proceeded through oxalate precipitate and phosphorus by the phosphomolibdate technique. A set of conditions yielding high purity HA was established.

Various analytical techniques used for the measurement of isotopic purity of heavy water at Madras Atomic Power Station

International Nuclear Information System (INIS)

Satyanarayanan, V.; Umapathy, P.; Bhaskaran, R.; Nagarajan, J.; Pradeep, Jeena; Ayyar, S.R.

2008-01-01

The paper deals with the various techniques used for the measurement of isotopic purity of heavy water samples received from different sources viz. reactor systems, heavy water upgrading plant and fresh consignment from heavy water production plants. Heavy water is used in PHWRs as moderator and primary coolant. Isotopic Purity is an important parameter to be monitored/analysed regularly for both the systems. There is a minimum isotopic purity level to be maintained in the moderator system due to neutron economy/fuel burnup and in the case of coolant system the measurement is of paramount importance due to its safety considerations. The selection of the method of analysis depends on the isotopic range. The techniques used to measure the isotopic purity of heavy water are a) Infrared Spectrophotometry b) Refractometry c) Densitometry. Infrared spectrometer uses the property of molecular absorption of IR radiation by HOD species and the absorbance is the measure of isotopic purity. This technique is generally used for measuring high isotopic (80-99.98%) and low isotopic samples. Refractometer uses the property of refractive index of heavy water. The difference in refractive indices of light water and heavy water is 0.0048. A 1 % change in D 2 O concentration would thus equal to 0.000048 refractive index units. This method is used for determining the approximate isotopic value of a sample. Density meter uses the property of difference in densities of light and heavy water. The difference in density of 99.999% D 2 O and light water is 0.107540 which covers the whole range of interest. The experience gained with these techniques in the measurements of isotopic purity of various samples are presented in this paper. (author)

Animal Sex: Purity Education and the Naturalization of the Abstinence Agenda

Science.gov (United States)

Sethna, Christabelle

2010-01-01

An early-twentieth-century movement for social purity in England, Canada and the United States aimed to eradicate prostitution, the double standard of sexual morals and their dreaded corollary, the venereal diseases. Social purists suggested that "purity education" for children was the best pedagogical prophylaxis against such…

Production Situation and Technology Prospect of Medical Isotopes

Directory of Open Access Journals (Sweden)

GAO Feng;LIN Li;LIU Yu-hao;MA Xing-jun

2016-10-01

Full Text Available The isotope production technology was overviewed, including traditional and newest technology. The current situation of medical isotope production was introduced. The problems faced by isotope supply and demand were analyzed. The future development trend of medical isotopes and technology prospect were put forward. As the most populous country, nuclear medicine develops rapidly, however, domestic isotope mainly relies on imports. The highly productive and relatively safe MIPR is expected to be an effective way to breakthrough the bottleneck of the development of nuclear medicine. Traditional isotope production technologies with reactor can be improved. It's urgent to research and promote new isotope production technologies with reactor. Those technologies which do not depend on reactor will have a bright market prospects.

The radiochemical purity of radiotracers as the criterion of their usefulness in investigations of hydrocarbons distillation

International Nuclear Information System (INIS)

Kolaczkowski, M.

1976-01-01

Among numerous analytic techniques of separation and analysis of radioactive products gas radiochromatography has proved to be particularly suitable. Organic bromides labelled with 82 Br-radionuclide are investigated. The analytic gas chromatographs equipped with appropriately constructed radiochromatographic attachments are used. The results of radiochemical purity determination of radiotracers are compared for various techniques. (author)

Disgust sensitivity is primarily associated with purity-based moral judgments.

Science.gov (United States)

Wagemans, Fieke M A; Brandt, Mark J; Zeelenberg, Marcel

2018-03-01

Individual differences in disgust sensitivity are associated with a range of judgments and attitudes related to the moral domain. Some perspectives suggest that the association between disgust sensitivity and moral judgments will be equally strong across all moral domains (i.e., purity, authority, loyalty, care, fairness, and liberty). Other perspectives predict that disgust sensitivity is primarily associated with judgments of specific moral domains (e.g., primarily purity). However, no study has systematically tested if disgust sensitivity is associated with moral judgments of the purity domain specifically, more generally to moral judgments of the binding moral domains, or to moral judgments of all of the moral domains equally. Across 5 studies (total N = 1,104), we find consistent evidence for the notion that disgust sensitivity relates more strongly to moral condemnation of purity-based transgressions (meta-analytic r = .40) than to moral condemnation of transgressions of any of the other domains (range meta-analytic rs: .07-.27). Our findings are in line with predictions from Moral Foundations Theory, which predicts that personality characteristics like disgust sensitivity make people more sensitive to a certain set of moral issues. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Locating Purity within Corruption Rumors: Narratives of HPV Vaccination Refusal in a Peri-urban Community of Southern Romania.

Science.gov (United States)

Pop, Cristina A

2016-12-01

This article locates the symbolic construction of "corrupted purity"-as a key assertion in Romanian parents' HPV vaccination refusal narratives-within a multiplicity of entangled rumors concerning reproduction and the state. Romania's unsuccessful HPV vaccination campaign is not unique. However, the shifting discourses around purity and corruption-through which some parents conveyed anxieties about their daughters being targeted for the vaccine-place a particular twist on the Romanian case of resisting the HPV vaccination. Parental discourses took the form of clusters of rumors about state medicine's failure to provide adequate reproductive health care, additive-laden foods, and exposure to radioactive contamination. In these rumors, corruption becomes literally embodied, through ingestion, consumption, contact, or inoculation. Parental discourses about what is being injected into their daughters' pristine bodies express their uncertainty around navigating the unsettled post-socialist medical landscape. © 2016 by the American Anthropological Association.

The effective management of medical isotope production in research reactors

International Nuclear Information System (INIS)

Drummond, D.T.

1993-01-01

During the 50-yr history of the use of radioisotopes for medical applications, research reactors have played a pivotal role in the production of many if not most of the key products. The marriage between research reactors and production operations is subject to significant challenges on two fronts. The medical applications of the radioisotope products impose some unique constraints and requirements on the production process. In addition, the mandates and priorities of a research reactor are not always congruent with the demands of a production environment. This paper briefly reviews the historical development of medical isotope production, identifies the unique challenges facing this endeavor, and discusses the management of the relationship between the isotope producer and the research reactor operator. Finally, the key elements of a successful relationship are identified

Time, Temperature and Amount of Distilled Water Effects on the Purity and Yield of Bis(2-hydroxyethyl Terephthalate Purification System

Directory of Open Access Journals (Sweden)

H.W. Goh

2015-07-01

Full Text Available Polyethylene terephthalate (PET bottle is one of the common plastic wastes existed in the municipal solid waste in Malaysia. One alternative to solve the abundant of PET wastes is chemical recycling of the wastes to produce a value added product. This technology not only can decrease the PET wastes in landfill sites but also can produce many useful recycled PET products. Bis(2-hydroxyethyl terephthalate (BHET obtained from glycolysis reaction of PET waste was purified using crystallization process. The hot distilled water was added to glycolysis product followed by cooling and filtration to extract BHET in white solid form from the product. The effect of three operating conditions namely crystallization time, crystallization temperatures and amount of distilled water used to the yield of crystallization process were investigated. The purity of crystallization products were analyzed using HPLC and DSC. The optimum conditions of 3 hours crystallization time, 2 °C crystallization temperature and 5:1 mass ratio of distilled water used to glycolize solid gave the highest yield and purity of the crystallization process. © 2015 BCREC UNDIP. All rights reservedReceived: 12nd August 2014; Revised: 4th February 2015; Accepted: 5th February 2015How to Cite: Goh, H.W., Salmiaton, A., Abdullah, N., Idris, A. (2015. Time, Temperature and Amount of Distilled Water Effects on the Purity and Yield of Bis(2-hydroxyethyl Terephthalate Purification System. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (2: 143-154. (doi:10.9767/bcrec.10.2.7195.143-154 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.7195.143-154  

Synthesis of High Purity Nonsymmetric Dialkylphosphinic Acid Extractants.

Science.gov (United States)

Wang, Junlian; Xie, Meiying; Liu, Xinyu; Xu, Shengming

2017-10-19

We present the synthesis of (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid as an example to demonstrate a method for the synthesis of high purity nonsymmetric dialkylphosphinic acid extractants. Low toxic sodium hypophosphite was chosen as the phosphorus source to react with olefin A (2,3-dimethyl-1-butene) to generate a monoalkylphosphinic acid intermediate. Amantadine was adopted to remove the dialkylphosphinic acid byproduct, as only the monoalkylphosphinic acid can react with amantadine to form an amantadine∙mono-alkylphosphinic acid salt, while the dialkylphosphinic acid cannot react with amantadine due to its large steric hindrance. The purified monoalkylphosphinic acid was then reacted with olefin B (diisobutylene) to yield nonsymmetric dialkylphosphinic acid (NSDAPA). The unreacted monoalkylphosphinic acid can be easily removed by a simple base-acid post-treatment and other organic impurities can be separated out through the precipitation of the cobalt salt. The structure of the (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid was confirmed by 31 P NMR, 1 H NMR, ESI-MS, and FT-IR. The purity was determined by a potentiometric titration method, and the results indicate that the purity can exceed 96%.

Recovery of high-purity hydrogen from COG

Energy Technology Data Exchange (ETDEWEB)

Tsukiyama, Y

1982-01-01

A general account of the latest trends in the recovery of high-purity hydrogen from coke oven gas (COG), the article being based on both Japanese and overseas literature: 1) Deep-freeze separation: impurities are liquefied and removed. This method make use of the fact that hydrogen is hard to liquefy. 2) The PSA method: high-purity hydrogen is recovered by the adsorption of other constituents at high pressures. This technique makes use of the fact that the adsorption capacity of an adsorbent varies with the partial pressure of the substances being adsorbed. 3) Membrane separation: a permeation separation method that uses a functional polymer separation membrane, and that depends on the fact that hydrogen has a low molecular weight in comparison with the other constituents. (19 refs.) (In Japanese)

Feasibility studies of radiation sterilization of some pharmaceutical products

International Nuclear Information System (INIS)

Gopal, N.G.S.; Rajagopalan, S.; Sharma, G.

1975-01-01

The paper deals with some studies carried out to evaluate the feasibility of radiation sterilization or treatment of some medical products and pharmaceuticals of immediate importance to their respective industries. The products include penicillin G sodium, ampicillin sodium, tetracyclin hydrochloride ointment,hydrocortisone acetate and its ointment, aqueous sodium chloride solutions (0.9 and 20%), fluorescein sodium strips, urea, ethylmorphine hydrochloride, aqueous solution of chlorobutanol and one of its commercial preparations, phenylmercuric nitrate and its aqueous solutions, aqueous solutions of methyl and propyl paraben, lactose, gum karaya, absorbent cotton and poly-(vinyl chloride) based medical products. The irradiated products have been examined for pharmacopoeial specifications wherever available. In general the products have been examined for changes in colour, pH, ultra-violet and infra-red absorption spectra. Thin-layer chromatographic analyses have been carried out to establish the purity of some of the irradiated products. The feasibility or otherwise of radiation sterilization or treatment of the various products from the physicochemical and microbiological (pharmacological) clinical considerations is also described. (author)

Production of medical short-lived radionuclides in Canada

International Nuclear Information System (INIS)

Wiebe, L.I.

1985-01-01

The production of radionuclides for medical and biomedical research in Canada has been reviewed with respect to the national geographic and demographic characteristics which influence their use. The types of facilities available for the production of short-lived radionuclides have been summarized, and a tabulation of the radionuclides that are produced has been presented. In broad terms production facilities can be classified as belonging to one of two groups, nuclear reactor or charged-particle accelerators. The charged-particle accelerators produce the more neutron-deficient and (because of the resultant decay properties) the more useful radionuclides for medical application. The nuclear reactor facilities for radionuclide production range in size and capacity from the high-flux research reactors of AECL to the six SLOWPOKE reactors, five of which are located on university campuses across the country. The McMaster University reactor is used to produce curie quantities of fluorine-18 weekly. Millicurie amounts of a large number of radionuclides, most of which have half-lives ranging from 2 to 50 hr, are produced in the low-flux reactors, in support of basic medical research

Improvement in fuel utilization in pressurized heavy water reactors due to increased heavy water purity

International Nuclear Information System (INIS)

Balakrishnan, M.R.

1991-01-01

This paper reports that in a pressurized heavy water reactor (PHWR), the reactivity of the reactor and, consequently, the discharge burnup of the fuel depend on the isotopic purity of the heavy water used in the reactor. The optimal purity of heavy water used in PHWRs, in turn, depends on the cost of fabricated uranium fuel and on the incremental cost incurred in improving the heavy water purity. The physics and economics aspects of the desirability of increasing the heavy water purity in PHWRs in India were first examined in 1978. With the cost data available at that time, it was found that improving the heavy water purity from 99.80% to 99.95% was economically attractive. The same problem is reinvestigated with current cost data. Even now, there is sufficient incentive to improve the isotopic purity of heavy water used in PHWRs. Admittedly, the economic advantage that can be derived depends on the cost of the fabricated fuel. Nevertheless, irrespective of the economics, there is also a fairly substantial saving in natural uranium. That the increase in the heavy water purity is to be maintained only in the low-pressure moderator system, and not in the high-pressure coolant system, makes the option of achieving higher fuel burnup with higher heavy water purity feasible

Medical Radioisotopes Production Without A Nuclear Reactor

Energy Technology Data Exchange (ETDEWEB)

Van der Keur, H.

2010-05-15

This report is answering the key question: Is it possible to ban the use of research reactors for the production of medical radioisotopes? Chapter 2 offers a summarized overview on the history of nuclear medicine. Chapter 3 gives an overview of the basic principles and understandings of nuclear medicine. The production of radioisotopes and its use in radiopharmaceuticals as a tracer for imaging particular parts of the inside of the human body (diagnosis) or as an agent in radiotherapy. Chapter 4 lists the use of popular medical radioisotopes used in nuclear imaging techniques and radiotherapy. Chapter 5 analyses reactor-based radioisotopes that can be produced by particle accelerators on commercial scale, other alternatives and the advantages of the cyclotron. Chapter 6 gives an overview of recent developments and prospects in worldwide radioisotopes production. Chapter 7 presents discussion, conclusions and recommendations, and is answering the abovementioned key question of this report: Is it possible to ban the use of a nuclear reactor for the production of radiopharmaceuticals? Is a safe and secure production of radioisotopes possible?.

Statistical distribution of the local purity in a large quantum system

International Nuclear Information System (INIS)

De Pasquale, A; Pascazio, S; Facchi, P; Giovannetti, V; Parisi, G; Scardicchio, A

2012-01-01

The local purity of large many-body quantum systems can be studied by following a statistical mechanical approach based on a random matrix model. Restricting the analysis to the case of global pure states, this method proved to be successful, and a full characterization of the statistical properties of the local purity was obtained by computing the partition function of the problem. Here we generalize these techniques to the case of global mixed states. In this context, by uniformly sampling the phase space of states with assigned global mixedness, we determine the exact expression of the first two moments of the local purity and a general expression for the moments of higher order. This generalizes previous results obtained for globally pure configurations. Furthermore, through the introduction of a partition function for a suitable canonical ensemble, we compute the approximate expression of the first moment of the marginal purity in the high-temperature regime. In the process, we establish a formal connection with the theory of quantum twirling maps that provides an alternative, possibly fruitful, way of performing the calculation. (paper)

Confined recrystallization of high-purity aluminium during accumulative roll bonding of aluminium laminates

International Nuclear Information System (INIS)

Chekhonin, Paul; Beausir, Benoît; Scharnweber, Juliane; Oertel, Carl-Georg; Hausöl, Tina; Höppel, Heinz Werner; Brokmeier, Heinz-Günter; Skrotzki, Werner

2012-01-01

Aluminium laminates consisting of high-purity aluminium and commercially pure aluminium have been produced by accumulative roll bonding (ARB) at ambient temperature for up to 10 cycles. To study the microstructure and texture development of the high-purity aluminium layers with regard to the shrinking layer thickness during ARB, microstructure and texture investigations were carried out by electron backscatter diffraction and neutron and X-ray diffraction, respectively. While the commercially pure aluminium layers develop an ultrafine-grained microstructure, partial discontinuous recrystallization occurs in the high-purity layers. The texture of the high-purity layers mainly consists of Cube and “Tilted Cube” (tilted with respect to the transverse direction) components. The experimental results are discussed with respect to confined recrystallization in the ARB aluminium laminates.

The Research about Preparation of High Purity Hexachlorodisilane

Science.gov (United States)

Wan, Ye; Zhao, Xiong; Yan, Dazhou; Zhao, Yu; Guo, Shuhu; Wang, Lei; Yang, Dian

2017-12-01

This article demonstrated a technology for producing high purity hexachlorodisilane what is one raw material of Semiconductor industry, which using the method of combination adsorption with rectification, whose material was from polysilicon residues of polysilicon company. This technology could remove most high boiling points chloro-silicane impurities and metal impurities effectively. The purity of Si2Cl6 produced by this technology can be up to 99.9%, the content of metal impurities can be low at 4ppb, which can meet the requirement of industy using completely. The technology extends the routes of Si2Cl6 in localization, having the advantages of simple process, continuous operation, and large capacity and so on.

[METHOD OF INCREASING MICROBIOLOGICAL PURITY OF POWDER FROM COCOA-VELLA].

Science.gov (United States)

Magomedov, G O; Cheremushkina, L V; Plotnikova, I V

2015-01-01

In the article there is described in detail the characteristic of the product of processing cocoa beans--cocoa-vella, there is presented a comparative analysis of the chemical composition, quality indices, the dispersive pattern, microbiological indices of the powder from the cocoa-vella in comparison to cocoa powder, obtained by traditional technology from the core of the cocoa beans. To improve the microbiological purity of the powder from the cocoa-vella there was suggested to be the modern and environmentally safe manner for the preparation of the powder The use of cocoa-vella disinfecting power by means of the electromagnetic field of ultrahigh frequency (RF EMF) was established to allow to obtain a product that meets the requirements of Technical Regulations of the Customs Union (TRCU 021/2011) on Food Safety. This work is of practical interest, since it helps to improve the safety of the powder from the cocoa-vella, and thus the quality of confectionery and food products based on it, which is relevant in terms of the management of a healthy diet.

Production of 123 I for medical diagnosis application

International Nuclear Information System (INIS)

Britto, J.L.Q. de.

1982-01-01

A method for production of carrier free 123 I with high radionuclidic purity in which the processing is done remotely was developed at Instituto de Engenharia Nuclear in Rio de Janeiro. The 123 I is produced in the decay of 123 Xe which is obtained through the reaction 122 Te ( 3 He, 2 n) 123 Xe with 30 MeV 3 He beams of IEN's variable energy cyclotron. The irradiated natural Te O 2 target is heated in a furnace at 675 0 C and the diffused out 123 Xe is adsorbed in a copper trap maintained at -196 0 C. The 123 Xe is allowed to decay during 6.3 hours and the 123 I produced washed out of the trap with a 0.1 N solution of NaOH. All the process is remotely controlled by using electric and pneumatic systems as well as manipulators and tongs. The quality control was achieved by atomic absorption and gamma-ray spectroscopy. (author)

Jerusalem artichoke powder: a useful material in producing high-optical-purity l-lactate using an efficient sugar-utilizing thermophilic Bacillus coagulans strain.

Science.gov (United States)

Wang, Limin; Xue, Zhangwei; Zhao, Bo; Yu, Bo; Xu, Ping; Ma, Yanhe

2013-02-01

Jerusalem artichoke is a low-requirement crop, which does not interfere with food chain, and is a promising carbon source for industrial fermentation. Microbial conversion of such a renewable raw material to useful products, such as lactic acid, is an important objective in industrial biotechnology. In this study, high-optical-purity l-lactate was efficiently produced from the hydrolysates of Jerusalem artichoke powder by a thermophilic bacterium, Bacillus coagulans XZL4. High l-lactate production (134gl(-1)) was obtained using 267gl(-1) Jerusalem artichoke powder (total reducing sugars of 140gl(-1)) and 10gl(-1) of corn steep powder in fed-batch fermentation, with an average productivity of 2.5gl(-1)h(-1) and a yield of 0.96gg(-1) reducing sugars. The final product optical purity is 99%, which meets the requirement of lactic acid polymerization. Our study represents a cost-effective and promising method for polymer-grade l-lactate production using a cheap raw bio-resource. Copyright © 2012 Elsevier Ltd. All rights reserved.

A High-Purity Alumina for Use in Studies of Shock Loaded Samples

Science.gov (United States)

Lacina, David; Neel, Christopher

2017-06-01

We report the results of plate impact experiments on a potential new ``standard'' material, Coorstek Plasmapure-UC (99.9% purity) polycrystalline alumina, for use in non-conduction, impact environment, shock loading studies. This work was motivated by a desire to find a 99.9% purity alumina to replace the now unavailable Coors Vistal (99.9%) alumina, as it was hoped the Hugoniot elastic limit (HEL) of the new standard would match the 9-11 GPa value of Vistal. Shock response data, including the HEL, Hugoniot particle velocities, Hugoniot shock velocities, stress vs volume, and release wave speeds, was obtained up to 14 GPa. This data will be compared with Hugoniot curve data for other high purity alumina to contrast differences in the shock response, and is intended to be useful in impedance matching calculations. We will show that the HEL of Plasmapure-UC alumina is 5.5 GPa and speculate on causes for this lower than expected value. We will also explore why the elastic-plastic response for Plasmapure-UC alumina differs from what has been observed from other high purity alumina. The final result of this work is to recommend a well-characterized, lower purity alumina (Coorstek AD-995) as a potential new ``standard'' material.

High-temperature mechanical properties of high-purity 70 mass% Cr-Fe alloy

Energy Technology Data Exchange (ETDEWEB)

Asahina, M.; Harima, N.; Takaki, S.; Abiko, K. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

2002-01-16

An ingot of high-purity 70 mass% Cr-Fe alloy was prepared by high-frequency induction melting in a high-purity argon atmosphere using a cold copper crucible. Its tensile properties such as hot-ductility and tensile strength were measured, and compared with the results for a high-purity 50 mass% Cr-Fe alloy, a high-purity 60 mass% Cr-Fe alloy and a Ni-based super-alloy. The formation of {sigma}-phase was also examined. The purity of a 70Cr-Fe alloy (70 mass% Cr-Fe alloy) ingot is more than 99.98 mass% and the total amount of gaseous impurities (C, N, O, S, H) in the 70Cr-Fe alloy is 69.9 mass ppm. The strength of the 70Cr-Fe alloy is higher than those of the 60Cr-Fe alloy and the 50Cr-Fe alloy at the temperatures between 293 and 1573 K, without decrease in ductility with increasing Cr content. The 70Cr-Fe alloy also possesses excellent high-temperature ductility. The {sigma}-phase was not observed after aging of 3.6 Ms at 873 K. Consequently, the 70Cr-Fe alloy is an excellent alloy as the base of super heat-resistant alloys. (orig.)

MIS High-Purity Plutonium Oxide Hydride Product 5501579 (SSR124): Final Report

Energy Technology Data Exchange (ETDEWEB)

Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Narlesky, Joshua Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinex, Max A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carillo, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-08

A high-purity plutonium dioxide material from the Material Identification and Surveillance (MIS) Program inventory has been studied with regard to gas generation and corrosion in a storage environment. Sample 5501579 represents process plutonium oxides from hydride oxide from Rocky Flats that are currently stored in 3013 containers. After calcination to 950°C, the material contained 87.42% plutonium with no major impurities. This study followed over time, the gas pressure of a sample with nominally 0.5 wt% water in a sealed container with an internal volume scaled to 1/500th of the volume of a 3013 container. Gas compositions were measured periodically over a six year period. The maximum observed gas pressure was 124 kPa. The increase over the initial pressure of 70 kPa was primarily due to generation of nitrogen and carbon dioxide gas. Hydrogen and oxygen were minor components of the headspace gas. At the completion of the study, the internal components of the sealed container showed signs of corrosion.

Growth and characterization of high-purity SiC single crystals

Science.gov (United States)

Augustine, G.; Balakrishna, V.; Brandt, C. D.

2000-04-01

High-purity SiC single crystals with diameter up to 50 mm have been grown by the physical vapor transport method. Finite element analysis was used for thermal modeling of the crystal growth cavity in order to reduce stress in the grown crystal. Crystals are grown in high-purity growth ambient using purified graphite furniture and high-purity SiC sublimation sources. Undoped crystals up to 50 mm in diameter with micropipe density less than 100 cm -2 have been grown using this method. These undoped crystals exhibit resistivities in the 10 3 Ω cm range and are p-type due to the presence of residual acceptor impurities, mainly boron. Semi-insulating SiC material is obtained by doping the crystal with vanadium. Vanadium has a deep donor level located near the middle of the band gap, which compensates the residual acceptor resulting in semi-insulating behavior.

Tuning for optimal performance in angle control, uniformity, and energy purity

International Nuclear Information System (INIS)

Liebert, Reuel B.; Olson, Joseph C.; Arevalo, Edwin A.; Downey, Daniel F.

2005-01-01

Advances in reducing the sizes of device structures and line widths place increasing demands on the accuracy of dopant placement and the control of dopant motion during activation anneals. Serial process high current ion implantation systems seek to produce beams in which the angles are controlled to high precision avoiding the angles introduced by conical structures used for holding wafers on spinning discs in batch systems. However, ion optical corrections and control of incident beam angle, dose uniformity, high throughput and energy purity often present apparently contradictory requirements in machine design. Data is presented to illustrate that tuning procedures can be used to simultaneously optimize angle purity in both x and y planes as well as control energy purity and dose uniformity

[Research on determination of chemical purity of andrographolide by coulometric titration method].

Science.gov (United States)

Yang, Ning; Yang, Dezhi; Xu, Lishen; Lv, Yang

2010-04-01

The determination of chemical purity of andrographolide by coulometric titration method is studied in this paper. The coulometric titration was carried out in a mixture composed of 4 mol x L(-1) hydrochloric acid and 1 mol x L(-1) potassium bromide solution and 1 mol x L(-1) potassium nitrate solution (1:1). Bromine is electrogenerated at the anode and reacts with the andrographolide. The number of electrons involved in the eleatrode reaction is 2. Purity of andrographolide is 99.76% compared with 99.77% utilizing area normalization method by HPLC. The RSD are 0.33% and 0.02% respectively. The results from two methods are consistent, so the determination of chemical purity of andrographolide by coulometric titration method is scientific and feasible. The method is rapid, simple, convenient, sensitive and accurate. The reference material is not essential in the method. The method is suitable for determination of chemical purity of andrographolide.

Increase of the radiochemical purity of aqueous solutions of compounds labelled with 131I using a ClAg sterile column

International Nuclear Information System (INIS)

Pliego, O.H.; Mitta, A.E.A.

1980-01-01

The use of a C1Ag sterile column that may be easily assembled at any nuclear medical center is proposed. The column is easy to handle and allows to obtain aqueous solutions of compounds labelled with radioactive iodine, with a radiochemical purity greater than 99%, conserving pH values, activity concentration, apyretogenia and sterility, the controls of toxicity and presence of heavy metals being negative. (C.A.K) [es

Development of high purity niobium material for superconducting cavities

International Nuclear Information System (INIS)

Umezawa, Hiroaki; Takeuchi, Koichi; Sakita, Kohei; Suzuki, Takafusa; Saito, Kenji; Noguchi, Shuichi.

1993-01-01

For the superconducting niobium cavities, issues of thermal quench and field emission have to be solved to achieve a high field gradient (>25MV/m) for TESLA (TeV Energy Superconducting Linear Accelerator). In order to overcome the quench, upgrading of thermal conductivity of niobium material at the low temperature is very important. On the reduction of the field emission not only dust particles but also defect, impurity and inhomogeneity should be considered. Therefore development of high purity niobium material is very important to solve these issues. This paper describes the our latest R and D for high purity niobium material. (author)

N-isopropyl-4-[123I]iodoamphetamine (123I-IMP) products. A difference in radiochemical purity, unmetabolized fraction, and octanol extraction fraction in arterial blood and regional brain uptake in rats

International Nuclear Information System (INIS)

Kanai, Yasukazu; Hasegawa, Shinji; Kimura, Yasuyuki; Oku, Naohiko; Hatazawa, Jun; Ito, Hiroshi; Fukuda, Hiroshi

2007-01-01

N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP) is a lipophilic compound utilized for cerebral blood flow (CBF) measurement with single photon emission computed tomography (SPECT). Two different 123 I-IMP products (IMP A and IMP B ) are commercially available. We examined the radiochemical purity, unmetabolized fraction, and octanol extraction fraction in arterial blood, and the regional brain uptake of IMP A and IMP B in a rat model. IMP B (96.4%±0.08%, P A (95.5%±0.20%). The mean unmetabolized fraction in arterial blood taken at 10 min after intravenous administration of IMP B (69.5%±4.4%, P A (59.6%±2.6%). The mean octanol extraction fraction of IMP B (75.0%±1.3%, P A (67.2%±0.8%). The mean levels of radioactivity in arterial blood sampled at 10 min after injection and mean regional brain radioactivity (cerebral cortices, basal ganglia, brain stem, and cerebellum) at 10-12 min after injection were not significantly different between IMP A and IMP B . The present study indicates differences in the radiochemical purity and the unmetabolized and octanol extraction fraction in arterial blood between the two commercially available 123 I-IMP products. The appropriate octanol extraction fractions for IMP A and IMP B should be determined in humans and employed for quantitative CBF measurement in clinical SPECT. (author)

Nuclear data for production of therapeutic radionuclides. Summary report of second research coordination meeting

International Nuclear Information System (INIS)

Sublet, J.-Ch.; Capote Noy, R.

2004-11-01

A summary is given of the Second Research Coordination Meeting on Nuclear Data for Production of Therapeutic Radionuclides. The new library of evaluated cross section will cover the reactor and/or accelerator production of therapeutic radionuclides to appropriate specific activities and purity along with the relevant decay data. There are a significant number of radioisotopes in use or being proposed for therapeutic applications. As a consequence of the work undertaken during the course of this CRP, the resulting completeness and accuracy of the nuclear data for the production of these nuclides to appropriate specific activities and purity along with the re-definition of their decay data should be adequate for safe and efficient medical applications. The radioisotopes to be considered in the CRP were divided into two categories: Established Radioisotopes (therapeutic radioisotopes that have established clinical uses) and Emerging Radioisotopes (less-commonly used but potentially interesting radioisotopes for which medical applications have been demonstrated). Experimental data compilations and selection and preliminary evaluations for each of the reactions were extensively discussed during the meeting. The recommendations for both established and emerging radionuclides, and validation/testing of the cross section library are summarized. Technical discussions and the resulting work plan of the Coordinated Research Programme are summarized for every reaction path to be evaluated, along with actions and deadlines. Participants' contributions to the RCM are also attached. (author)

Evolution of PET and SPECT tracers from cyclotrons: production and application

International Nuclear Information System (INIS)

Stoecklin, G.

1992-01-01

Small cyclotrons play an increasing role in the production of medically useful isotopes. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are major tools in modern nuclear medicine for monitoring regional physiological and pharmacological functions at a molecular level. This requires physiological substrates or drugs labeled with suitable positron emitters or single photon emitters. Short-lived neutron deficient radioisotopes of high specific activity and high radionuclidic purity are needed. Some examples of radionuclide production, the development of radiopharmaceuticals for PET and SPECT, and their applications is presented with special emphasis on fluorine-18 and iodine-123. (author)

Preparation, radiochemical purity control and stability of 99mTc-mertiatide (Mag-3)

International Nuclear Information System (INIS)

Van Hemert, F.J.; Schimmel, K.J.M.; Van Eck-Smit, B.L.F.; Van Lenthe, H.

2005-01-01

Scintigraphic image analysis of 99m Tc-mertiatide (Mag-3, mercaptoacetyltriglycine) clearance provides the determination of the blood flow, the tubular transit time and the excretion as well from both kidneys. Radiopharmaceutical routine recommends a radiochemical purity control before administration of the product to a patient. The main objective of this study is to develop a Mag-3 labeling procedure that fits better than the previous one in our daily routine production of radiopharmaceuticals. Increasing proportions of 99m Tc-Mag-3 were measured during the heating and cooling steps of the Mag-3 labeling procedure. High performance liquid chromatography (HPLC) analysis was used to confirm the results of a rapid radiochemical quality control assay on standard instant thin-layer chromatography-silica gel (ITLC-SG) paper. The reconstitution time takes 20-25 minutes from the harvest of pertechnetate to a ready-for-use calibrated patient syringe. The HPLC profile of 99m Tc-Mag-3 including its minor impurities remains unchanged for 24-48 hours after reconstitution. The application of a programmable Peltier-directed device for heating/cooling provides a better control of the temperature course. The procedure proposed fully meets the labeling criteria recommended by the supplier and can be performed with a minimum of attention within a time-span that we formerly needed for solely the radiochemical purity control assay. Moreover, 99m Tc-Mag-3 prepared in this way seems to be considerably more stable than mentioned in the manufacturer's instructions. (author)

ASTM lights the way for tissue engineered medical products standards: jump start for combination medical products that restore biological function of human tissues.

Science.gov (United States)

Picciolo, G L; Stocum, D L

2001-01-01

Everybody hopes for better health and restoration of impaired bodily function, and now that hope is illuminated by the promise of powerful biological tools that make human cells grow and replace human tissue. ASTM Committee F04 on Medical and Surgical Materials and Devices is taking the lead by defining some of those tools as standards that can be used for the development, production, testing, and regulatory approval of medical products.

Characterisation of two AGATA asymmetric high purity germanium capsules

International Nuclear Information System (INIS)

Colosimo, S.J.; Moon, S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Harkness-Brennan, L.; Judson, D.S.; Lazarus, I.H.; Nolan, P.J.; Simpson, J.; Unsworth, C.

2015-01-01

The AGATA spectrometer is an array of highly segmented high purity germanium detectors. The spectrometer uses pulse shape analysis in order to track Compton scattered γ-rays to increase the efficiency of nuclear spectroscopy studies. The characterisation of two high purity germanium detector capsules for AGATA of the same A-type has been performed at the University of Liverpool. This work will examine the uniformity of performance of the two capsules, including a comparison of the resolution and efficiency as well as a study of charge collection. The performance of the capsules shows good agreement, which is essential for the efficient operation of the γ-ray tracking array

Characterisation of two AGATA asymmetric high purity germanium capsules

Energy Technology Data Exchange (ETDEWEB)

Colosimo, S.J., E-mail: sjc@ns.ph.liv.ac.uk [Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Moon, S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Harkness-Brennan, L.; Judson, D.S. [Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.H. [STFC Daresbury, Daresbury, Warrington WA4 4AD (United Kingdom); Nolan, P.J. [Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Simpson, J. [STFC Daresbury, Daresbury, Warrington WA4 4AD (United Kingdom); Unsworth, C. [Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

2015-02-11

The AGATA spectrometer is an array of highly segmented high purity germanium detectors. The spectrometer uses pulse shape analysis in order to track Compton scattered γ-rays to increase the efficiency of nuclear spectroscopy studies. The characterisation of two high purity germanium detector capsules for AGATA of the same A-type has been performed at the University of Liverpool. This work will examine the uniformity of performance of the two capsules, including a comparison of the resolution and efficiency as well as a study of charge collection. The performance of the capsules shows good agreement, which is essential for the efficient operation of the γ-ray tracking array.

Spectral Purity Enhancement via Polyphase Multipath Circuits

NARCIS (Netherlands)

Mensink, E.; Klumperink, Eric A.M.; Nauta, Bram

2004-01-01

The central question of this paper is: can we enhance the spectral purity of nonlinear circuits by using polyphase multipath circuits? The basic idea behind polyphase multipath circuits is to split the nonlinear circuits into two or more paths and exploit phase differences between these paths to

Effect of Aluminum Purity on the Pore Formation of Porous Anodic Alumina

International Nuclear Information System (INIS)

Kim, Byeol; Lee, Jin Seok

2014-01-01

Anodic alumina oxide (AAO), a self-ordered hexagonal array, has various applications in nanofabrication such as the fabrication of nanotemplates and other nanostructures. In order to obtain highly ordered porous alumina membranes, a two-step anodization or prepatterning of aluminum are mainly conducted with straight electric field. Electric field is the main driving force for pore growth during anodization. However, impurities in aluminum can disturb the direction of the electric field. To confirm this, we anodized two different aluminum foil samples with high purity (99.999%) and relatively low purity (99.8%), and compared the differences in the surface morphologies of the respective aluminum oxide membranes produced in different electric fields. Branched pores observed in porous alumina surface which was anodized in low-purity aluminum and the size; dimensions of the pores were found to be usually smaller than those obtained from high-purity aluminum. Moreover, anodization at high voltage proceeds to a significant level of conversion because of the high speed of the directional electric field. Consequently, anodic alumina membrane of a specific morphology, i. e., meshed pore, was produced

Effect of Aluminum Purity on the Pore Formation of Porous Anodic Alumina

Energy Technology Data Exchange (ETDEWEB)

Kim, Byeol; Lee, Jin Seok [Sookmyung Women' s Univ., Seoul (Korea, Republic of)

2014-02-15

Anodic alumina oxide (AAO), a self-ordered hexagonal array, has various applications in nanofabrication such as the fabrication of nanotemplates and other nanostructures. In order to obtain highly ordered porous alumina membranes, a two-step anodization or prepatterning of aluminum are mainly conducted with straight electric field. Electric field is the main driving force for pore growth during anodization. However, impurities in aluminum can disturb the direction of the electric field. To confirm this, we anodized two different aluminum foil samples with high purity (99.999%) and relatively low purity (99.8%), and compared the differences in the surface morphologies of the respective aluminum oxide membranes produced in different electric fields. Branched pores observed in porous alumina surface which was anodized in low-purity aluminum and the size; dimensions of the pores were found to be usually smaller than those obtained from high-purity aluminum. Moreover, anodization at high voltage proceeds to a significant level of conversion because of the high speed of the directional electric field. Consequently, anodic alumina membrane of a specific morphology, i. e., meshed pore, was produced.

Radiation sterilization of medical products- current trends and future prospects

International Nuclear Information System (INIS)

Sharma, G.

1997-01-01

In medical practice use of sterile pharmaceuticals and single use disposable medical devices is steadily increasing. Sterile pharmaceuticals like injections and ophthalmic ointments are required for therapy. Medical devices are employed for diagnostic, drug administration or corrective purposes, and as implants for temporary, short term or long term residence in the human system. All these products are made available in sterile form by treating them to a suitable process of sterilization i.e. dry/wet heat, ethylene oxide (EtO) gas or ionizing radiation. In this paper current trends and future prospects of radiation sterilization of medical products are given in detail. 9 refs., 7 tabs

Surface passivation of high purity granular metals: zinc, cadmium, lead

Directory of Open Access Journals (Sweden)

Pirozhenko L. A.

2017-10-01

Full Text Available For the high purity metals (99.9999%, such as zinc, cadmium, and lead, which are widely used as initial components in growing semiconductor and scintillation crystals (CdTe, CdZnTe, ZnSe, (Cd, Zn, Pb WO4, (Cd, Zn, Pb MoO4 et al., it is very important to ensure reliable protection of the surface from oxidation and adsorption of impurities from the atmosphere. The specific features of surface passivation of high purity cadmium, lead and zinc are not sufficiently studied and require specific methodologies for further studies. The use of organic solutions in the schemes of chemical passivation of the investigated metals avoids hydrolysis of the obtained protective films. The use of organic solvents with pure cation and anion composition as the washing liquid prevents chemisorption of ions present in the conventionally used distilled water. This keeps the original purity of the granular metals. Novel compositions of etchants and etching scheme providing simultaneous polishing and passivation of high purity granular Zn, Cd and Pb are developed. Chemical passivation allows storing metals in the normal atmospheric conditions for more than half a year for Zn and Cd and up to 30 days for Pb without changing the state of the surface. The use of the glycerol-DMF solution in the processes for obtaining Pb granules provides self-passivation of metal surfaces and eliminates the additional chemical processing while maintaining the quality of corrosion protection.

Influence of Storage Temperature on Radiochemical Purity of 99mTc-Radiopharmaceuticals.

Science.gov (United States)

Uccelli, Licia; Boschi, Alessandra; Martini, Petra; Cittanti, Corrado; Bertelli, Stefania; Bortolotti, Doretta; Govoni, Elena; Lodi, Luca; Romani, Simona; Zaccaria, Samanta; Zappaterra, Elisa; Farina, Donatella; Rizzo, Carlotta; Giganti, Melchiore; Bartolomei, Mirco

2018-03-15

The influence of effective room temperature on the radiochemical purity of 99m Tc-radiopharmaceuticals was reported. This study was born from the observation that in the isolators used for the preparation of the 99m Tc-radiopharmaceuticals the temperatures can be higher than those reported in the commercial illustrative leaflets of the kits. This is due, in particular, to the small size of the work area, the presence of instruments for heating, the continuous activation of air filtration, in addition to the fact that the environment of the isolator used for the 99m Tc-radiopharmaceuticals preparation and storage is completely isolated and not conditioned. A total of 244 99m Tc-radiopharmaceutical preparations (seven different types) have been tested and the radiochemical purity was checked at the end of preparation and until the expiry time. Moreover, we found that the mean temperature into the isolator was significantly higher than 25 °C, the temperature, in general, required for the preparation and storage of 99m Tc-radiopharmaceuticals. Results confirmed the radiochemical stability of radiopharmaceutical products. However, as required in the field of quality assurance, the impact that different conditions than those required by the manufacturer on the radiopharmaceuticals quality have to be verified before human administration.

Prospects for radiation sterilization of medical products in Egypt

International Nuclear Information System (INIS)

Roushdy, H.M.

1975-01-01

The pharmaceutical industry in Egypt is continually expanding its activity and each year marks new accomplishments and additions which enable the companies to apply the most modern scientific means in the production of pharmaceutical preparations and consequently to improve their market potentialities. The certainty of expansion and the possibility of increasing exports of sterilized medical products, particularly to Arab and African countries, indicate a need for a gamma-sterilization plant. This technology permits the introduction of the latest practices with regard to used disposables, thus greatly reducing the chances of cross-contamination which usually results in serious complications enhanced by local environmental conditions. This paper reviews the current state and future prospects for radiation sterilization of medical products and biological tissues in connection with other related industrial radiation processings. Moreover, the paper reviews the Egyptian scientific and technical experience with irradiation facilities and the parameters underlying the choice of Egypt's first industrial gamma and electron-beam irradiators designed for more than a single-purpose use, with hygienic measures taken to avoid biological contamination of sterilized medical packages throughout the sterilization process. In addition, the paper deals with the policy set up for establishing the Egyptian National Centre for Radiation Technology with a view to introducing irradiation techniques in the sterilization of medical products, and to improving the properties and increasing the competitiveness of Egyptian fabrics. Apart from medical sterilization, certain industrial processes have been mentioned to show how a multi-purpose irradiation facility may be utilized in a developing country to justify significantly the large investment required. (author)

Differential scanning calorimetry method for purity determination: A case study on polycyclic aromatic hydrocarbons and chloramphenicol

International Nuclear Information System (INIS)

Kestens, V.; Zeleny, R.; Auclair, G.; Held, A.; Roebben, G.; Linsinger, T.P.J.

2011-01-01

Highlights: → Purity assessment of polycyclic aromatic hydrocarbons and chloramphenicol by DSC. → DSC results compared with traditional purity methods. → Different methods give different results, multiple method approach recommended. → DSC sensitive to impurities that have similar structures as main component. - Abstract: In this study the validity and suitability of differential scanning calorimetry (DSC) to determine the purity of selected polycyclic aromatic hydrocarbons and chloramphenicol has been investigated. The study materials were two candidate certified reference materials (CRMs), 6-methylchrysene and benzo[a]pyrene, and two different batches of commercially available highly pure chloramphenicol. The DSC results were compared with those obtained by other methods, namely gas and liquid chromatography with mass spectrometric detection, liquid chromatography with diode array detection, and quantitative nuclear magnetic resonance. The purity results obtained by these different analytical methods confirm the well-known challenges of comparing results of different method-defined measurands. In comparison with other methods, DSC has a much narrower working range. This limits the applicability of DSC as purity determination method, for instance during the assignment of the purity value of a CRM. Nevertheless, this study showed that DSC can be a powerful technique to detect impurities that are structurally very similar to the main purity component. From this point of view, and because of its good repeatability, DSC can be considered as a valuable technique to investigate the homogeneity and stability of candidate purity CRMs.

The radiochemical purity of technetium-99m-tin-diethylene-triamino-pentaacetic acid (DTPA) complex

International Nuclear Information System (INIS)

Besnard, M.; Costerousse, O.; Merlin, L.; Coehn, Y.

1975-01-01

The effect on radiochemical purity was studied as a function of the storage period of tin-DTPA solution and of the technetium-complex solution. The quantity of the pertechnetate ions present in the solution is determined by ascending paper chromatography, and an attempt was made to clarify the bond type of technetium by a spectrophotometric method. The tin-DTPA solutions for complexing of the reduced technetium are stable over a period of 8 weeks. The yield of the radiopharmaceutical product is better than 95%. (G.Gy.)

Radiation sterilization of medical products in the Philippines

Science.gov (United States)

Singson, C.; Carmona, C.; de Guzman, Z.; Barrun, W.; Lanuza, L.

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. Hence, the materials used were directly obtained from local manufacturers. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. These studies indicated that radiation sterilization is technically feasible for locally manufactured medical products.

Material science as basis for nuclear medicine: Holmium irradiation for radioisotopes production

Science.gov (United States)

Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko

2018-05-01

Material Science, being an interdisciplinary field, plays important roles in nuclear science. These applications are seen in weaponry, armoured vehicles, accelerator structure and development, semiconductor detectors, nuclear medicine and many more. Present study presents the applications of some metals in nuclear medicine (radioisotope production). The charged-particle-induced nuclear reactions by using cyclotrons or accelerators have become a very vital feature of the modern nuclear medicine. Realising the importance of excitation functions for the efficient production of medical radionuclides, some very high purity holmium metals are generally prepared or purchased for bombardment in nuclear accelerators. In the present work, various methods to obtain pure holmium for radioisotope production have been discussed while also presenting details of our present studies. From the experimental work of the present studies, some very high purity holmium foils have been used in the work for a comprehensive study of residual radionuclides production cross-sections. The study was performed using a stacked-foil activation technique combined with γ-ray spectrometry. The stack was bombarded with 50.4 MeV alpha particle beam from AVF cyclotron of RI Beam Factory, Nishina Centre for Accelerator-Based Science, RIKEN, Japan. The work produced thulium radionuclides useful in nuclear medicine.

Improving the radiochemical purity determination of 123I-labeled metaiodobenzylguanidine

International Nuclear Information System (INIS)

Luciana Carvalheira; Paulo Bechara Dutra; Paula Fernandes de Aguiar

2014-01-01

The HPLC method originally applied at the Nuclear Engineering Institute (IEN) for the radiochemical purity determination of 123iodine labeled m-iodobenzylguanidine ( 123 I-mIBG) takes 18.5 min. The final product release also depends on this result, and to facilitate this stage, we aimed to decrease this analysis time. We also intended to use fewer toxic compounds, if feasible. The optimization approach used herein was a combination of factorial and mixture designs to study simultaneously the selected variables. Analysis time, resolution and chromatograms aspect were the measured responses. The qualitative analysis of these responses provided the best chromatographic separation conditions that were 52 mM KH 2 PO 4 in a solution of ethanol and water (1:1), applying a flow rate of 0.50 mL min -1 and C18 column (4.6 × 250 mm, 5 μm). These optimum conditions not only decreased the analysis time in 61 %, but also allowed the reduction of mobile phase toxicity. To assure reliable data, method validation was performed for these conditions. The method has proved its specificity, the detection limit found was 3.70 × 10 -4 MBq mL -1 and the quantification limit has corresponded to 1.11 × 10 -3 MBq mL -1 . Repeatability and intermediate precision has not exceeded 3 and 5 %, respectively, and the accuracy has matched the interval of 95-105 %. This new method has been routinely applied in the radiochemical purity determination of 123 I-mIBG at IEN. (author)

78 FR 12329 - Distinguishing Medical Device Recalls From Product Enhancements; Reporting Requirements; Draft...

Science.gov (United States)

2013-02-22

... medical devices to take timely action to correct violative devices or remove them from the marketplace...] Distinguishing Medical Device Recalls From Product Enhancements; Reporting Requirements; Draft Guidance for... draft guidance entitled ``Distinguishing Medical Device Recalls From Product Enhancements; Reporting...

Clinical experience with Optivate®, high-purity factor VIII (FVIII) product with von Willebrand factor (VWF) in young children with haemophilia A.

Science.gov (United States)

Matysiak, M; Bobrowska, H; Balwierz, W; Chybicka, A; Kowalczyk, J R; Shaikh-Zaidi, R; Gillanders, K; Dash, C H

2011-09-01

Optivate® is a high-purity FVIII/VWF product. Its safety, tolerability and efficacy in subjects ≥ 12 years have been demonstrated. This study was undertaken to assess Optivate® in children with haemophilia A. Twenty-five children, including one PUP (previously untreated patient), aged 1-6 years (mean 4.67 years) were treated with Optivate® for 26 weeks. Inhibitors were assessed every 3 months and viral status at the study start and end. Prophylaxis was used by five boys and on demand by twenty. The mean number of bleeds in the study was lower compared to the same period pre-study (12.0/child vs. 16.2/child), with fewer bleeds (P related events (5%), all were mild and non-serious. There were no clinically significant changes in vital signs, viral transmissions or inhibitors. In young children Optivate® was well tolerated, safe and efficacious. © 2011 Blackwell Publishing Ltd.

Production of high-purity isotopes by electromagnetic separation; Production electromagnetique d'isotope tres purs

Energy Technology Data Exchange (ETDEWEB)

Cassignol, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Improvement in isotopic purity of nuclides prepared by electromagnetic separation is searched into the principle of cascades of monochromators. The principal drawback of which is to allow the separation of only one isotope at a time. The electromagnetic separator of Saclay is equipped with an electrostatic post-analyzer, which is described. Significant results are obtained, concerning isotopic enhancements of uranium-235 and mercury-204. A schema of isotopic contagion is then proposed, the basis of it is the scattering of the primary ions in the residual atmosphere of the separator chamber. The most frequent type of collisions being accompanied by neutralisation of the ions, the schema explains the efficiency of the second stage. As a matter of conclusion, some particularities concerning the routine work at a high enhancement, small output machine, are given. (author) [French] L'accroissement de la purete isotopique des especes nucleaires preparees par separation electromagnetique est recherche dans l'emploi du principe des cascades de monochromateurs, moyennant la servitude de ne collecter qu'un isotope a la fois. Le separateur electromagnetique de Saclay est equipe dans ce but d'un post-analyseur electrostatique, qui est decrit. Des resultats significatifs sont donnes, portant sur les enrichissements obtenus dans les separations d'uranium-235 et de mercure-204. Un schema de contagion isotopique est propose. Il est fonde sur la diffusion a petit angle accompagnant la neutralisation des faisceaux primaires par collision avec le gaz residuel. Ce schema permet d'expliquer l'efficacite de l'etage electrostatique. En matiere de conclusion, la methode d'exploitation d'une machine a faible debit et a haut enrichissement est donnee. (auteur)

NONWOVEN TEXTILES WITH MEDICAL DESTINATION ROMANIAN PRODUCTION

Directory of Open Access Journals (Sweden)

BULACU Romulus

2015-05-01

Full Text Available The widest range of medical disposable from nonwoven textiles are: absorbent and hygiene products : (diapers, feminine care, incontinence from the layered structures absorbent or impervious; use products such as hospital operating theaters sterile clothing (caps, gowns, masks, shoe coverings, materials for field operators, lab coats, packaging materials for hot or cold treatments, sterile materials (wipes, bandages, sterile bandages, etc.. Currently these materials, in their majority, are imported. This paper presents research done for getting, with the country equipment, disposable medical products from 40 g/m2 nonwoven textile materials. The technology adopted for the purpose, in SC "Minet" S.A. Ramnicu Valcea, Romania consisted of the following steps:Carding - folding, the aggregate Spinnbau-Hergeth type, Germany, with major changes carding technology adjustment and folding, to obtain a fibrous layer with a mass per unit surface of about 40-50 g / m2 and a width of 2,1 m;Pre-heat consolidation by pre-heating required only to ensure product stability required minimal interphase transport to final consolidation. Final thermal consolidation of the fibrous layer by thermal calendering at a temperature of 110°C and calenders cylinder speed of 2 m / min. The processing of the fiber by carding - folding and preliminary thermally consolidation and final by calendering.

Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1977-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel as many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products. (auth)

Pressure-assisted sintering of high purity barium titanate

NARCIS (Netherlands)

van den Cruijsem, S.; Varst, van der P.G.T.; With, de G.; Bortzmeyer, D.; Boussuge, M.; Chartier, Th.; Hausonne, J.M.; Mocellin, A.; Rousset, A.; Thevenot, F.

1997-01-01

The dielectric behaviour of High Purity Barium titanate (HPB) ceramics is strongly dependent on the grain size and porosity. For applications, control of grain size and porosity is required. Pressure-assisted sintering techniques at relatively low temperatures meet these requirements. In this study,

Event timing in high purity germanium coaxial detectors

International Nuclear Information System (INIS)

El-Ibiary, M.Y.

1979-08-01

The timing of gamma ray radiation in systems using high purity coaxial germanium detectors is analyzed and compared to that of systems using Ge(Li) detectors. The analysis takes into account the effect of the residual impurities on the electric field distribution, and hence on the rate of rise of the electrical pulses delivered to the timing module. Conditions under which the electric field distribution could lead to an improvement in timing performance, are identified. The results of the analysis confirm the experimental results published elsewhere and when compared with those for Ge(Li) detectors, which usually operate under conditions of charge carrier velocity saturation, confirm that high purity germanium detectors need not have inferior timing characteristics. A chart is given to provide a quantitative basis on which the trade off between the radius of the detector and its time resolution may be made

Optical fiber design with orbital angular momentum light purity higher than 99.9.

Science.gov (United States)

Zhang, Zhishen; Gan, Jiulin; Heng, Xiaobo; Wu, Yuqing; Li, Qingyu; Qian, Qi; Chen, Dongdan; Yang, Zhongmin

2015-11-16

The purity of the synthesized orbital-angular-momentum (OAM) light in the fiber is inversely proportional to channel crosstalk level in the OAM optical fiber communication system. Here the relationship between the fiber structure and the purity is firstly demonstrated in theory. The graded-index optical fiber is proposed and designed for the OAM light propagation with the purity higher than 99.9%. 16 fiber modes (10 OAM modes) have been supported by a specific designed graded-index optical fiber with dispersion less than 35 ps/(km∙nm). Such fiber design has suppressed the intrinsic crosstalk to be lower than -30 dB, and can be potentially used for the long distance OAM optical communication system.

Synthesis of high purity rutile nanoparticles from medium-grade Egyptian natural ilmenite

Directory of Open Access Journals (Sweden)

Mohamed G. Shahien

2015-09-01

Full Text Available The Egyptian magmatic ilmenite is classified as a medium-grade ore. The present work is an attempt to produce a high-quality TiO2 that can be used in several industries from this medium-grade raw material using the mechanical activation, carbothermic reduction, hydrochloric acid leaching and calcination. A mixture from the ilmenite (FeTiO3 and activated carbon was milled for 30 h. This mixture was annealed at 1200 °C for one hour and the product was leached by hydrochloric acid and calcined at 600 °C for two hours. The role of the ball milling was to grind the raw ilmenite to obtain the nano size, and the carbothermic reduction was to reduce all the Fe-Ti phases to a mixture from Fe metal and TiO2. Leaching procedure was carried out to remove all the Fe metal and obtain a high-grade TiO2. After leaching and calcination of the milled and annealed mixture of FeTiO3/C under the optimal conditions, TiO2 nanoparticles with a size of 10–100 nm and purity more than 95% were obtained. The qualifications of the synthesized high purity rutile nanoparticles from the Egyptian natural ilmenite match the conditions of many industrial applications.

Determination of nanoparticle surface coatings and nanoparticle purity using microscale thermogravimetric analysis.

Science.gov (United States)

Mansfield, Elisabeth; Tyner, Katherine M; Poling, Christopher M; Blacklock, Jenifer L

2014-02-04

The use of nanoparticles in some applications (i.e., nanomedical, nanofiltration, or nanoelectronic) requires small samples with well-known purities and composition. In addition, when nanoparticles are introduced into complex environments (e.g., biological fluids), the particles may become coated with matter, such as proteins or lipid layers. Many of today's analytical techniques are not able to address small-scale samples of nanoparticles to determine purity and the presence of surface coatings. Through the use of an elevated-temperature quartz crystal microbalance (QCM) method we call microscale thermogravimetric analysis, or μ-TGA, the nanoparticle purity, as well as the presence of any surface coatings of nanomaterials, can be measured. Microscale thermogravimetric analysis is used to determine the presence and amount of surface-bound ligand coverage on gold nanoparticles and confirm the presence of a poly(ethylene glycol) coating on SiO2 nanoparticles. Results are compared to traditional analytical techniques to demonstrate reproducibility and validity of μ-TGA for determining the presence of nanoparticle surface coatings. Carbon nanotube samples are also analyzed and compared to conventional TGA. The results demonstrate μ-TGA is a valid method for quantitative determination of the coatings on nanoparticles, and in some cases, can provide purity and compositional data of the nanoparticles themselves.

Spectroscopic Determination of Trace Contaminants in High Purity Oxygen

Science.gov (United States)

Hornung, Steven D.

2011-01-01

Oxygen used for extravehicular activities (EVA) must be free of contaminants because a difference in a few tenths of a percent of argon or nitrogen content can mean significant reduction in available EVA time. These inert gases build up in the extravehicular mobility unit because they are not metabolized or scrubbed from the atmosphere. Measurement of oxygen purity above 99.5% is problematic, and currently only complex instruments such as gas chromatographs or mass spectrometers are used for these determinations. Because liquid oxygen boil-off from the space shuttle will no longer be available to supply oxygen for EVA use, other concepts are being developed to produce and validate high purity oxygen from cabin air aboard the International Space Station. A prototype optical emission technique capable of detecting argon and nitrogen below 0.1% in oxygen was developed at White Sands Test Facility. This instrument uses a glow discharge in reduced pressure gas to produce atomic emission from the species present. Because the atomic emission lines from oxygen, nitrogen, and argon are discrete and in many cases well-separated, trace amounts of argon and nitrogen can be detected in the ultraviolet and visible spectrum. This is a straightforward, direct measurement of the target contaminants and may lend itself to a device capable of on-orbit verification of oxygen purity. System design and optimized measurement parameters are presented.

Purity and crystallinity of microwave synthesized antimony sulfide microrods

Energy Technology Data Exchange (ETDEWEB)

Martínez-Alonso, Claudia, E-mail: claudiamartinezalonso30@gmail.com [Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, 76010 (Mexico); Olivos-Peralta, Eliot U. [Instituto de Energías Renovables, Universidad NacionalAutónoma de México, Temixco, Morelos, 62580 (Mexico); Sotelo-Lerma, Mérida [Universidad de Sonora, Hermosillo, Sonora, 83000 (Mexico); Sato-Berrú, Roberto Y. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, MéxicoD.F., 04510 (Mexico); Mayén-Hernández, S.A. [Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, 76010 (Mexico); Hu, Hailin, E-mail: hzh@ier.unam.mx [Instituto de Energías Renovables, Universidad NacionalAutónoma de México, Temixco, Morelos, 62580 (Mexico)

2017-01-15

Antimony sulfide (Sb{sub 2}S{sub 3}) is a promising semiconductor material for solar cell applications. In this work, microrods of Sb{sub 2}S{sub 3} were synthesized by microwave heating with different sulfur sources, solvents, temperature, heating rate, power, and solution concentration. It was found that 90% of stoichiometric Sb{sub 2}S{sub 3} can be obtained with thiourea (TU) or thioacetamide (TA) as sulfur sources and that their optical band gap values were within the range of 1.59–1.60 eV. The most crystalline Sb{sub 2}S{sub 3} were obtained by using TU. The morphology of the Sb{sub 2}S{sub 3} with TU the individual rods were exhibited, whereas rods bundles appeared in TA-based products. The solvents were ethylene glycol (EG) and dimethylformamide (DMF). EG generates more heat than DMF during the microwave synthesis. As a result, the Sb{sub 2}S{sub 3} obtained with EG contained a larger percentage of oxygen and smaller crystal sizes compared to those from DMF. On the other hand, the length and diameter of Sb{sub 2}S{sub 3} microrods can be increased by applying higher heating power although the crystal size did not change at all. In summary, pure and highly crystalline Sb{sub 2}S{sub 3} microrods of 6–10 μm long and 330–850 nm in diameter can be obtained by the microwave method with a careful selection of chemical and thermodynamic parameters of the synthesis. - Highlights: • Purity up to 90% of crystalline Sb{sub 2}S{sub 3} nanorods can be obtained by microwave heating. • The combination of solvent and sulfide type affects crystallinity & purity of Sb2S3. • The high pressure generated in microwave heating helps to form Sb{sub 2}S{sub 3} nanorods.

Purity and crystallinity of microwave synthesized antimony sulfide microrods

International Nuclear Information System (INIS)

Martínez-Alonso, Claudia; Olivos-Peralta, Eliot U.; Sotelo-Lerma, Mérida; Sato-Berrú, Roberto Y.; Mayén-Hernández, S.A.; Hu, Hailin

2017-01-01

Antimony sulfide (Sb_2S_3) is a promising semiconductor material for solar cell applications. In this work, microrods of Sb_2S_3 were synthesized by microwave heating with different sulfur sources, solvents, temperature, heating rate, power, and solution concentration. It was found that 90% of stoichiometric Sb_2S_3 can be obtained with thiourea (TU) or thioacetamide (TA) as sulfur sources and that their optical band gap values were within the range of 1.59–1.60 eV. The most crystalline Sb_2S_3 were obtained by using TU. The morphology of the Sb_2S_3 with TU the individual rods were exhibited, whereas rods bundles appeared in TA-based products. The solvents were ethylene glycol (EG) and dimethylformamide (DMF). EG generates more heat than DMF during the microwave synthesis. As a result, the Sb_2S_3 obtained with EG contained a larger percentage of oxygen and smaller crystal sizes compared to those from DMF. On the other hand, the length and diameter of Sb_2S_3 microrods can be increased by applying higher heating power although the crystal size did not change at all. In summary, pure and highly crystalline Sb_2S_3 microrods of 6–10 μm long and 330–850 nm in diameter can be obtained by the microwave method with a careful selection of chemical and thermodynamic parameters of the synthesis. - Highlights: • Purity up to 90% of crystalline Sb_2S_3 nanorods can be obtained by microwave heating. • The combination of solvent and sulfide type affects crystallinity & purity of Sb2S3. • The high pressure generated in microwave heating helps to form Sb_2S_3 nanorods.

Physical and mechanical metallurgy of high purity Nb for accelerator cavities

International Nuclear Information System (INIS)

Bieler, T.R.; Wright, N.T.; Pourboghrat, F.; Compton, C.; Hartwig, K.T.; Baars, D.; Zamiri, A.; Chandrasekaran, S.; Darbandi, P.; Jiang, H.; Skoug, E.; Balachandran, S.; Ice, G.E.; Liu, W.

2010-01-01

In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

Production and evaluation of (multimodal) answers to medical questions

NARCIS (Netherlands)

van Hooijdonk, C.M.J.; Krahmer, E.; Maes, A.; Theune, Mariet; Bosma, W.E.; Maes, A.; Ainsworth, S.

This paper describes two experiments carried out to investigate the production and evaluation of multimodal answer presentations in the context of a medical question answering system. In a production experiment participants had to produce answers to different types of questions. The results show

Medications Containing Aspirin (Acetylsalicylate) and Aspirin-Like Products

Science.gov (United States)

updated 3/10/08 Medications Containing Aspirin (Acetylsalicylate) and Aspirin-Like Products © National Reye's Syndrome Foundation Inc. 2008 Epidemiologic research has shown an association between the development of Reye's ...

Syntheses of therapeutically active labelled molecules for metabolic and pharmacokinetic studies. Synthesis, preservation and radiochemical purity problems

International Nuclear Information System (INIS)

Pichat, L.

1977-01-01

Molecules labelled with radioactive isotopes are without question an essential tool for metabolic and pharmacokinetic studies. Carbon 14 is often preferred to tritium since it allows better observation of the fate of carbonated structures. The fact that 14 CO 2 alone is used as basic material is the distinguishing feature of syntheses with isotopic carbon. In many cases the synthesis schemes of labelled drugs diverge considerably or entirely from those normally adopted for the unlabelled product. It is usually necessary to work on micro-quantities in order to maintain high specific activities, which implies the use of special synthesis techniques and of chromatographic separation and purification methods. Radiochemical purity tests are carried out by thin layer, column and gas phase chromatography, purity and identity checks by mass spectrometry and by 13 C and proton RMN. Labelled products are radiolysed by interaction of excited species with the molecules of the compound, a phenomenon much faster with tritiated than with 14 C-labelled molecules. The radiolysis rates may be reduced by molecule dilution. For ethical reasons it is not convenient to use 14 C molecules in human experiments, but molecular labelled with stable isotopes ( 13 C, 15 N, D) can serve instead [fr

On organization of medical radionuclides production in Ukraine

International Nuclear Information System (INIS)

Zelens'kij, V.F.; Pilipenko, M.Yi.; Shulyika, M.G.; Skibyin, V.Yi.; Kostyin, V.Ya.; Vyikman, Ya.E.; Kalmikov, L.Z.; Nesterov, V.G.; Krasnoperova, A.P.

1994-01-01

Annual demand for radiopharmaceuticals in Ukraine is about 50.000 GBq and expenses for their purchase are about 1 - 2 mln US dollars per year. It determines expediency of their production in Ukraine. Taking into consideration the fact that one of the aftereffects of the accident at Chernobyl Atomic Power Station is inevitable increase of the number of oncological diseases (including malignant growths of the thyroid gland) the demand for radionuclides will be increasing steadily. Therefore, it is clear that organization of the centre for radiopharmaceuticals production will not solve the problem of providing radiological departments with them. One of the possible ways to solve the problem is creation of a network of regional centres for radioactive isotopes production. Realisation of the suggested program will allow to solve the problem of providing the medical establishments of Ukraine with medical radionuclides. Performed technical and economical evaluation shows that the expenses will be compensated in 2.9 years

Zone refining high-purity germanium

International Nuclear Information System (INIS)

Hubbard, G.S.; Haller, E.E.; Hansen, W.L.

1977-10-01

The effects of various parameters on germanium purification by zone refining have been examined. These parameters include the germanium container and container coatings, ambient gas and other operating conditions. Four methods of refining are presented which reproducibly yield 3.5 kg germanium ingots from which high purity (vertical barN/sub A/ - N/sub D/vertical bar less than or equal to2 x 10 10 cm -3 ) single crystals can be grown. A qualitative model involving binary and ternary complexes of Si, O, B, and Al is shown to account for the behavior of impurities at these low concentrations

The power of management in medical services. Can we manage better for higher quality and more productive medical services?

Directory of Open Access Journals (Sweden)

Magdalena BARBU

2010-06-01

Full Text Available Medical services are the most important services of all since we all depend on them. Their quality and productivity can assure a wealthy nation and therefore good economical results. The offer of medical services depends on medical personnel and more than this, on the management in the medical field since any resource not managed well or not managed at all is only a lost one, regardless its value. Management is therefore the key, the “how to” method of obtaining the desired result. The same approach can be applied into our study in order to reach more productive medical services which to prove high quality to all patients. We need to use and to squeeze the entire force of management tools in order to reach our goal: accessible medical services full of quality. The current worldwide crisis situation makes us think that after job and food, even medical services (also a basic thing after all can become a “luxury” although this should never happen. Therefore we must do whatever needed to improve the way medical organizations are driven so that the quality of their medical services will be better and better and the productivity will be at a higher level. Medical management should have as a goal making it possible for patients to be able to solve their health problems as soon as possible and as good as possible.

A proposed standard on medical isotope production in fission reactors

International Nuclear Information System (INIS)

Schenter, R. E.; Brown, G. J.; Holden, C. S.

2006-01-01

Authors Robert E. Sehenter, Garry Brown and Charles S. Holden argue that a Standard for 'Medical Isotope Production' is needed. Medical isotopes are becoming major components of application for the diagnosis and treatment of all the major diseases including all forms of cancer, heart disease, arthritis, Alzheimer's, among others. Current nuclear data to perform calculations is incomplete, dated or imprecise or otherwise flawed for many isotopes that could have significant applications in medicine. Improved data files will assist computational analyses to design means and methods for improved isotope production techniques in the fission reactor systems. Initial focus of the Standard is expected to be on neutron cross section and branching data for both fast and thermal reactor systems. Evaluated and reviewed tables giving thermal capture cross sections and resonance integrals for the major target and product medical isotopes would be the expected 'first start' for the 'Standard Working Group'. (authors)

Product-line administration: a framework for redefining medical record department services.

Science.gov (United States)

Postal, S N

1990-06-01

Product-line administration is a viable approach for managing medical records services in an environment that demands high quantity and quality service levels. Product-line administration directs medical record department team members to look outside of the department and seek input from the customers it is intended to serve. The feedback received may be alarming at first, as the current state of products usually reveals a true lack of customer input. As the planning, defining, managing, and marketing phases are implemented, the road will not be easy and rewards will be slow to come. Product-line administration does not provide quick fixes, but it does provide long-term problem resolution as products are refined and new products developed to meet customer needs and expectations. In addition to better meeting the needs of the department's external customers, the department's internal customers' needs and expectations will be addressed. The participative management approach will help nurture each team member's creativity. The team members will have the opportunity to reach their full potential while reaping the rewards and benefits of providing products and services that meet the needs and expectations of all department customers. The future of the health care industry promises more changes as the country moves toward some form of prospective payment in the ambulatory setting. Reactive management and the constant struggle to catch up can no longer be accepted as a management approach. It is imperative that the medical record department be viewed as a business with product lines composed of quality products. The planning, defining, managing, and marketing components of product-line administration afford responsiveness to the current situation and the development of quality products that will ensure that medical record departments are prepared for the future.

Production of high purity aluminas: II - Characterization

International Nuclear Information System (INIS)

Franceschini Filho, D.F.; Morschbacker, A.L.R.C.; Fonseca, M.C.; Mello, R.T. de; Ferreira Filho, J.M.

1987-01-01

This paper presents a characterization study on various samples of aluminum hidroxyde (pseudoboemite). Results of X-ray diffraction (identification, mean crystal size, degree of crystallinity); BET surface area and loss of ignition of the samples are displayed. The degree of crystallinity is found to be of great usefullness in the characterization of this kind of material. We point out the variety of products that can be obtained with the method of preparation used. (Author) [pt

The rapid synthesis of high purity [{sup 18}F]butyrophenone neuroleptics from nitro precursors for PET study

Energy Technology Data Exchange (ETDEWEB)

Hashizume, Kazunari; Hashimoto, Naoto; Kato, Hiroo; Cork, D G; Miyake, Yoshihiro [National Cardiovascular Center, Suita, Osaka (Japan)

1995-04-01

We have completed rapid syntheses of [{sup 18}F]butyrophenone neuroleptics ([{sup 18}F]haloperidol and [{sup 18}F]spiperone) from their nitro precursors in high radiochemical yields (up to 21%) by combining a one-step nitro-fluoro exchange reaction and a novel high performance liquid chromatography (HPLC) separation method. The synthesis time was ca. 95 min and both the radiochemical and chemical purities of the labeled products were over 99%. (author).

Analysis technique of impurity in high purity deuterium by cryogenic gas-chromatography

International Nuclear Information System (INIS)

Zhou Junbo; Gao Liping

2007-01-01

A veracious and applicable quantitative analysis method of O 2 , N 2 and H 2 , HD in high purity deuterium by the chromatogram columniation filled with 5A molecular sieve and alumina was researched and constituted at natural temperature and 77 K, respectively. Minimum detecting limit of the present method is (150-200) x 10 -6 for H 2 and HD, and it can meet the need of quantitative analysis of the impurity during high purity deuterium preparation. (authors)

Ehrenfest dynamics is purity non-preserving: A necessary ingredient for decoherence

International Nuclear Information System (INIS)

Alonso, J. L.; Clemente-Gallardo, J.; Cuchí, J. C.

2012-01-01

We discuss the evolution of purity in mixed quantum/classical approaches to electronic nonadiabatic dynamics in the context of the Ehrenfest model. As it is impossible to exactly determine initial conditions for a realistic system, we choose to work in the statistical Ehrenfest formalism that we introduced in Alonso et al. [J. Phys. A: Math. Theor. 44, 396004 (2011)]. From it, we develop a new framework to determine exactly the change in the purity of the quantum subsystem along with the evolution of a statistical Ehrenfest system. In a simple case, we verify how and to which extent Ehrenfest statistical dynamics makes a system with more than one classical trajectory, and an initial quantum pure state become a quantum mixed one. We prove this numerically showing how the evolution of purity depends on time, on the dimension of the quantum state space D, and on the number of classical trajectories N of the initial distribution. The results in this work open new perspectives for studying decoherence with Ehrenfest dynamics.

Country status of application, manufacturing and sterilization of single-use medical products

International Nuclear Information System (INIS)

Norimah Yusof

1986-01-01

The paper reviews the current status of application of single-use medical products in Malaysia. The status of their manufacturing and sterilization is also discussed. The increasing production of such items calls for a more reliable and efficient sterilization technique in particular, radiation sterilization. In line with the demand and the effort to increase local production of medical products, UTN would be providing irradiation service together with research and development in this particular field by 1988. (author)

Genome sequence of the thermophilic strain Bacillus coagulans 2-6, an efficient producer of high-optical-purity L-lactic acid.

Science.gov (United States)

Su, Fei; Yu, Bo; Sun, Jibin; Ou, Hong-Yu; Zhao, Bo; Wang, Limin; Qin, Jiayang; Tang, Hongzhi; Tao, Fei; Jarek, Michael; Scharfe, Maren; Ma, Cuiqing; Ma, Yanhe; Xu, Ping

2011-09-01

Bacillus coagulans 2-6 is an efficient producer of lactic acid. The genome of B. coagulans 2-6 has the smallest genome among the members of the genus Bacillus known to date. The frameshift mutation at the start of the d-lactate dehydrogenase sequence might be responsible for the production of high-optical-purity l-lactic acid.

Voltage-controlled colour-tunable microcavity OLEDs with enhanced colour purity

International Nuclear Information System (INIS)

Choy, Wallace C H; Niu, J H; Li, W L; Chui, P C

2008-01-01

The emission spectrum of single-unit voltage-controlled colour-tunable organic light emitting devices (OLEDs) has been theoretically and experimentally studied. Our results show that by introducing the microcavity structure, the colour purity of not only the destination colour but also the colour-tunable route can be enhanced, while colour purity is still an issue in typical single-unit voltage-controlled colour-tunable OLEDs. With the consideration of the periodical cycling of resonant wavelength and absorption loss of the metal electrodes, the appropriate change in the thickness of the microcavity structure has been utilized to achieve voltage-controlled red-to-green and red-to-blue colour-tunable OLEDs without adding dyes or other organic materials to the OLEDs

The analytical of radiochemical purity of tumor receptor imaging agent 99Tcm-octreotide

International Nuclear Information System (INIS)

Wang Xufu; Zuo Shuyao; Shao Wenbo; Wang Guoming; Sun Jianwen; Zhang Qin

2003-01-01

The radiochemical purity of tumor receptor imaging agent 99 Tc m -octreotide is measured by High Pressure Liquid Chromatography (HPLC) and two systems of chromatography combining method of silver stain. The results show that the radiochemical purity of 98 Tc m -octreotide measured by both methods are effective and correct. It can separate 99 Tc m -octreotide from other radioactive compositions correctly and effectively

Evaluation of radiochemical purities of some radiopharmaceuticals in Shiraz Namazi teaching hospital

Directory of Open Access Journals (Sweden)

Hossein Sadeghpour

2015-03-01

Full Text Available Many radiopharmaceuticals, as a special group of drugs, are eventually prepared at the nuclear medicine departments of the hospitals. Therefore, their quality control procedures such as sterility tests, radionuclide, radiochemical and chemical purity should be carried out in the hospitals. In this study, radiochemical purity for more than 300 preparations of three different radiopharmaceutical formulations from commercial kits were tested using instant thin layer chromatography. The formulations 99mTc-DTPA, 99mTc-MDP and 99mTc-MIBI were obtained from Pars Isotope Co. Several paper chromatographic systems including standard and factory recommended thin layer chromatography systems were used in this study. In addition different equipments for detection of radioactivity in paper chromatography like gamma camera and dose calibrator were used. The results showed that the most observed impurities were hydrolyzed reduced technetium (HR-Tc. There were no significant differences between calculated 99mTc-MIBI radiochemical purities when the radioactive detection device was gamma camera instead of dose calibrator. In case of 99mTc-DTPA and 99mTc-MDP, there were significant differences in detection of HR-Tc. On the contrary, no significant differences in free pertechnetate were observed when package insert procedures for quality control were used instead of those recommended in the references. Finally, we observed that the package insert procedures for quality control can offer higher radiochemical purities.

Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits. Pt. III

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1982-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel since many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products

Enhanced color purity of blue OLEDs based on well-design structure

Science.gov (United States)

Du, Qianqian; Wang, Wenjun; Li, Shuhong; Wang, Qingru; Xia, Shuzhen; Zhang, Bingyuan; Wang, Minghong; Fan, Quli

2016-09-01

We have fabricated blue organic light-emitting devices (OLEDs) with higher color purity and stability by optimizing the structure of the Glass/ITO/NPB(50 nm)/ BCzVBi (30 nm)/ TPBi (x nm)/Alq3(20 nm)/LiF/Al. The results show that the introducing of hole blocking layer(HBL) TPBi greatly can improve not only the color purity but the color stability, which owe to its higher the Highest Occupied Molecular Orbital (HOMO) energy levels of 6.2 eV. We expect our work will be useful to optimizing the blue OLEDs structure to enhancing the color property.

JOYO coolant sodium and cover gas purity control database (MK-II core)

International Nuclear Information System (INIS)

Ito, Kazuhiro; Nemoto, Masaaki

2000-03-01

The experimental fast reactor 'JOYO' served as the MK-II irradiation bed core for testing fuel and material for FBR development for 15 years from 1982 to 1997. During the MK-II operation, impurities concentrations in the sodium and the argon gas were determined by 67 samples of primary sodium, 81 samples of secondary sodium, 75 samples of primary argon gas, 89 samples of secondary argon gas (the overflow tank) and 89 samples of secondary argon gas (the dump tank). The sodium and the argon gas purity control data were accumulated from in thirty-one duty operations, thirteen special test operations and eight annual inspections. These purity control results and related plant data were compiled into database, which were recorded on CD-ROM for user convenience. Purity control data include concentration of oxygen, carbon, hydrogen, nitrogen, chlorine, iron, nickel and chromium in sodium, concentration of oxygen, hydrogen, nitrogen, carbon dioxide, methane and helium in argon gas with the reactor condition. (author)

Physical and mechanical metallurgy of high purity Nb for accelerator cavities

Directory of Open Access Journals (Sweden)

T. R. Bieler

2010-03-01

Full Text Available In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

Corrosion of high purity Fe-Cr-Ni alloys in 13 N boiling nitric acid

International Nuclear Information System (INIS)

Ohta, Joji; Mayuzumi, Masami; Kusanagi, Hideo; Takaku, Hiroshi

1998-01-01

Corrosion in boiling nitric acid was investigated for high purity Fe-18%Cr-12%Ni alloys and type 304L stainless steels (SS). Owing to very low impurity concentration, the solution treated high purity alloys show almost no intergranular corrosion while the type 304L SS show severe intergranular corrosion. Both in the high purity alloys and type 304L SS, aging treatments ranging from 873 K to 1073 K for 1 h enhance intergranular corrosion. During the aging treatments, impurities should be segregated to the grain boundaries. The corrosion behaviors were discussed from a standpoint of impurity segregation to grain boundaries. This study is of importance for purex reprocessing of spent fuels

Safety and clinical efficacy of some radiation-sterilized medical products and pharmaceuticals

International Nuclear Information System (INIS)

Kulkarni, R.D.; Gopal, N.G.S.

1975-01-01

Medical products and pharmaceuticals must conform to certain minimum physico-chemical microbiological and biological requirements. The biological requirements comprise principally testing for toxicity, safety, and pyrogens. Besides the above-mentioned criteria, there are two other important characteristics, viz. clinical efficacy and tolerance in animal and/or human beings. These latter requirements, expected from the final product released for general human use, are not carried out routinely. In the present-day pharmaceutical and medical technology, numerous mew products are appearing, many of them requiring radiation sterilization as they are not stable towards the other conventional methods of sterilization. While the post-irradiation physicochemical changes in a product may not be significant, the bio-availability or biological activity of the product may be affected to a more significant extent. Some evidence of this has recently been reported. Hence, it is desirable to carry out studies on safety as well as clinical efficacy on irradiated products. This paper describes some studies on plastic-based medical products, a pharmaceutical raw material, a typical infusion fluid such as normal saline, antibiotics and their ointments. (author)

Reactor production and separation of no-carrier added 32P for medical applications

International Nuclear Information System (INIS)

Vimalnath, K.V.; Shetty, P.; Rajeswari, A.; Chirayil, V.; Chakraborty, S.; Dash, A.

2014-01-01

Phosphorous-32 is an attractive and widely used therapeutic radionuclide owing to its favorable nuclear characteristics. The major application of 32 P is the treatment option for a distinct subgroup of elderly patients with polycythemia vera and leukemia. The tremendous prospects associated with the use of 32 P along with the challenge of providing 32 P of acceptable specific activity and purity amenable for in vivo therapy, led to development of a 32 P production strategy. The 32 S(n,p) 32 P route of production provide the scope of obtaining high specific activities or no carrier added (NCA) 32 P. In a typical batch of 14 nos. of neutron irradiated Al containers, each containing 18 g of sulphur, were processed. In the quest for an effective separation method to isolate micro gram of 32 P formed during the neutron irradiation of sulphur, the prospect of using distillation under reduced pressure to achieve complete removal of sulfur seemed to be an effective proposition and motivated us to adopt. The experimental parameters that influence the distillation were identified and a careful control has been exercised to ensure complete removal of sulphur from 32 P within reasonable time period. The 32 P remained in the distillation flask was quantitatively collected by leaching with 0.05 N HCl with gentle heating at 80℃ for 3 hours. In the light of the perceived need to remove cationic impurities from the 32 P leachate, it was passed through an ion-exchange chromatography column containing a cation exchange resin (Dowex 50 x 8 H + , 100-200 mesh) wherein all the cationic impurities get trapped and H 3 32 PO 4 solution was collected as effluent. Recognizing the fact that H 3 32 PO 4 produced is to be used for clinical applications, a thorough quality assessment was carried out. Radionuclidic purity was ascertained by a measurement of its half-life. In order to establish the absence of extraneous gamma emitting radionuclide impurities, gamma spectrum of the appropriately

Preparation of high purity nickel film from industrial effluent by the distribution of charge over microelectrodes using newly designed free electrolytic diffusion approach

International Nuclear Information System (INIS)

Ahmed, Sheikh Asrar; Qadir, Muhammad Abdul; Zafar, Muhammad Nadeem; Hussain, Ishtiaq; Tufail, Shahid; Rashid, Saima; Shah, Hamid Ali

2008-01-01

The present work deals with the development of a newly designed free electrolytic diffusion approach (the distribution of charge over microelectrodes) for the purification of metals and was successfully applied for the purification of nickel from the industrial effluent containing high proportion of nickel. Atomic absorption spectrophotometer (AAS) analyzed the purified nickel deposited on working microelectrodes. The results obtained show that the purity of nickel was enhanced from 95% to 99.9% with traces of copper etc. It was concluded that distribution of charge over the microcathodes at a rate of 50 cycles per second (cps) shows better results for the production of high purity (HP) nickel as compared to 25 cycles per second (cps)

Preparation of high purity nickel film from industrial effluent by the distribution of charge over microelectrodes using newly designed free electrolytic diffusion approach

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Sheikh Asrar; Qadir, Muhammad Abdul [Institute of Chemistry, University of the Punjab, Lahore, 54590 (Pakistan); Zafar, Muhammad Nadeem [Institute of Chemistry, University of the Punjab, Lahore, 54590 (Pakistan)], E-mail: znadeempk@yahoo.com; Hussain, Ishtiaq [Institute of Chemistry, University of the Punjab, Lahore, 54590 (Pakistan); Tufail, Shahid [PCSIR Laboratories Complex, Feroz pur Road, Lahore (Pakistan); Rashid, Saima; Shah, Hamid Ali [Institute of Chemistry, University of the Punjab, Lahore, 54590 (Pakistan)

2008-09-15

The present work deals with the development of a newly designed free electrolytic diffusion approach (the distribution of charge over microelectrodes) for the purification of metals and was successfully applied for the purification of nickel from the industrial effluent containing high proportion of nickel. Atomic absorption spectrophotometer (AAS) analyzed the purified nickel deposited on working microelectrodes. The results obtained show that the purity of nickel was enhanced from 95% to 99.9% with traces of copper etc. It was concluded that distribution of charge over the microcathodes at a rate of 50 cycles per second (cps) shows better results for the production of high purity (HP) nickel as compared to 25 cycles per second (cps)

Purity of targets prepared on Cu substrates

Science.gov (United States)

Méens, A.; Rossini, I.; Sens, J. C.

1993-09-01

The purity of several elemental self-supporting targets usually prepared by evaporation onto soluble Cu substrates has been studied. The targets were analysed by Rutherford backscattering and instrumental neutron activation analysis. Because of the high percentage of Cu observed in some Si targets, further measurements, including transmission electron microscopy, have been performed on Si targets deposited by e-gun bombardment onto Cu and ion-beam sputtering onto betaine.

Electronic medical records and efficiency and productivity during office visits.

Science.gov (United States)

Furukawa, Michael F

2011-04-01

To estimate the relationship between electronic medical record (EMR) use and efficiency of utilization and provider productivity during visits to US office-based physicians. Cross-sectional analysis of the 2006-2007 National Ambulatory Medical Care Survey. The sample included 62,710 patient visits to 2625 physicians. EMR systems included demographics, clinical notes, prescription orders, and laboratory and imaging results. Efficiency was measured as utilization of examinations, laboratory tests, radiology procedures, health education, nonmedication treatments, and medications. Productivity was measured as total services provided per 20-minute period. Survey-weighted regressions estimated association of EMR use with services provided, visit intensity/duration, and productivity. Marginal effects were estimated by averaging across all visits and by major reason for visit. EMR use was associated with higher probability of any examination (7.7%, 95% confidence interval [CI] = 2.4%, 13.1%); any laboratory test (5.7%, 95% CI = 2.6%, 8.8%); any health education (4.9%, 95% CI = 0.2%, 9.6%); and fewer laboratory tests (-7.1%, 95% CI = -14.2%, -0.1%). During pre/post surgery visits, EMR use was associated with 7.3% (95% CI= -12.9%, -1.8%) fewer radiology procedures. EMR use was not associated with utilization of nonmedication treatments and medications, or visit duration. During routine visits for a chronic problem, EMR use was associated with 11.2% (95% CI = 5.7%, 16.8%) more diagnostic/screening services provided per 20-minute period. EMR use had a mixed association with efficiency and productivity during office visits. EMRs may improve provider productivity, especially during visits for a new problem and routine chronic care.

Evaluation of the production capabilities of 18F, 11C, 13N and 15O PET isotopes at the PET-cyclotron-radiochemistry site of Messina University

Directory of Open Access Journals (Sweden)

Lucrezia Auditore

2017-02-01

Full Text Available The production of 18F, 11C, 13N, and 15O positron emitting radionuclides for PET imaging is usually accomplished in Nuclear Medicine Departments through direct nuclear reactions induced by protons accelerated by compact medical cyclotrons on liquid or gaseous targets. Messina University has funded the construction of a PET-cyclotron-radio-chemistry plant at the Messina University Hospital, equipped with a 11 MeV self-shielded cyclotron. We estimated the expected production yields of these nuclides, accounting for target thickness, production of other radioactive nuclides, and time effects on the irradiated target purity. To this aim, both TALYS code (v. 1.8 and an analytical approach based on EXFOR experimental data were used. The general agreement between the two approaches, and with the available literature data, allows to assess the expected yields at the End of Bombardment, and relative target purities, to be used for further radiopharmaceutical preparation steps.

Product-based Safety Certification for Medical Devices Embedded Software.

Science.gov (United States)

Neto, José Augusto; Figueiredo Damásio, Jemerson; Monthaler, Paul; Morais, Misael

2015-01-01

Worldwide medical device embedded software certification practices are currently focused on manufacturing best practices. In Brazil, the national regulatory agency does not hold a local certification process for software-intensive medical devices and admits international certification (e.g. FDA and CE) from local and international industry to operate in the Brazilian health care market. We present here a product-based certification process as a candidate process to support the Brazilian regulatory agency ANVISA in medical device software regulation. Center of Strategic Technology for Healthcare (NUTES) medical device embedded software certification is based on a solid safety quality model and has been tested with reasonable success against the Class I risk device Generic Infusion Pump (GIP).

Dosimetric systems of high dose, dose rate and dose uniformity in food and medical products

International Nuclear Information System (INIS)

Vargas, J.; Vivanco, M.; Castro, E.

2014-08-01

In the Instituto Peruano de Energia Nuclear (IPEN) we use the chemical dosimetry Astm-E-1026 Fricke as a standard dosimetric system of reference and different routine dosimetric systems of high doses, according to the applied doses to obtain the desired effects in the treated products and the doses range determined for each type of dosimeter. Fricke dosimetry is a chemical dosimeter in aqueous solution indicating the absorbed dose by means an increase in absorbance at a specific wavelength. A calibrated spectrophotometer with controlled temperature is used to measure absorbance. The adsorbed dose range should cover from 20 to 400 Gy, the Fricke solution is extremely sensitive to organic impurities, to traces of metal ions, in preparing chemical products of reactive grade must be used and the water purity is very important. Using the referential standard dosimetric system Fricke, was determined to March 5, 2013, using the referential standard dosimetric system Astm-1026 Fricke, were irradiated in triplicate Fricke dosimeters, to 5 irradiation times (20; 30; 40; 50 and 60 seconds) and by linear regression, the dose rate of 5.400648 kGy /h was determined in the central point of the irradiation chamber (irradiator Gamma cell 220 Excel), applying the decay formula, was compared with the obtained results by manufacturers by means the same dosimetric system in the year of its manufacture, being this to the date 5.44691 kGy /h, with an error rate of 0.85. After considering that the dosimetric solution responds to the results, we proceeded to the irradiation of a sample of 200 g of cereal instant food, 2 dosimeters were placed at the lateral ends of the central position to maximum dose and 2 dosimeters in upper and lower ends as minimum dose, they were applied same irradiation times; for statistical analysis, the maximum dose rate was 6.1006 kGy /h and the minimum dose rate of 5.2185 kGy /h; with a dose uniformity of 1.16. In medical material of micro pulverized bone for

Hydrogen concentration and distribution in high-purity germanium crystals

International Nuclear Information System (INIS)

Hansen, W.L.; Haller, E.E.; Luke, P.N.

1981-10-01

High-purity germanium crystals used for making nuclear radiation detectors are usually grown in a hydrogen ambient from a melt contained in a high-purity silica crucible. The benefits and problems encountered in using a hydrogen ambient are reviewed. A hydrogen concentration of about 2 x 10 15 cm -3 has been determined by growing crystals in hydrogen spiked with tritium and counting the tritium β-decays in detectors made from these crystals. Annealing studies show that the hydrogen is strongly bound, either to defects or as H 2 with a dissociation energy > 3 eV. This is lowered to 1.8 eV when copper is present. Etching defects in dislocation-free crystals grown in hydrogen have been found by etch stripping to have a density of about 1 x 10 7 cm -3 and are estimated to contain 10 8 H atoms each

SCK-CEN increases production of medical isotopes by half

International Nuclear Information System (INIS)

Ponsard, B.; Leysen, P.; Janssens, J.

2010-01-01

It is impossible to imagine the medical world today without radioisotopes, and due to rapid technological progress in nuclear medicine their use is still on the rise. An important role of research reactors is the production of molybdenum-99. Around the world this is done primarily by five nuclear research reactors, one of which is the BR2 reactor of SCK-CEN. As a result of checks and maintenance work on three other reactors, for a few years there has been a serious crisis in the availability of this medical isotope. In order to guarantee the worldwide supply of radioisotopes, SCK-CEN expanded its production of molybdenum-99 by 50 percent in 2010.

Scalable preparation of high purity rutin fatty acid esters following enzymatic synthesis

DEFF Research Database (Denmark)

Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

2010-01-01

Investigations into expanded uses of modified flavonoids are often limited by the availability of these high purity compounds. As such, a simple, effective and relatively fast method for isolation of gram quantities of both long and medium chain fatty acid esters of rutin following scaled......-up biosynthesis reactions was established. Acylation reactions of rutin and palmitic or lauric acids were efficient in systems containing dried acetone and molecular sieves, yielding from 70–77% bioconversion after 96 h. Thereafter, high purity isolates (>97%) were easily obtained in significant quantities...

Polarimetric purity and the concept of degree of polarization

Science.gov (United States)

Gil, José J.; Norrman, Andreas; Friberg, Ari T.; Setälä, Tero

2018-02-01

The concept of degree of polarization for electromagnetic waves, in its general three-dimensional version, is revisited in the light of the implications of the recent findings on the structure of polarimetric purity and of the existence of nonregular states of polarization [J. J. Gil et al., Phys Rev. A 95, 053856 (2017), 10.1103/PhysRevA.95.053856]. From the analysis of the characteristic decomposition of a polarization matrix R into an incoherent convex combination of (1) a pure state Rp, (2) a middle state Rm given by an equiprobable mixture of two eigenstates of R, and (3) a fully unpolarized state Ru -3 D, it is found that, in general, Rm exhibits nonzero circular and linear degrees of polarization. Therefore, the degrees of linear and circular polarization of R cannot always be assigned to the single totally polarized component Rp. It is shown that the parameter P3 D proposed formerly by Samson [J. C. Samson, Geophys. J. R. Astron. Soc. 34, 403 (1973), 10.1111/j.1365-246X.1973.tb02404.x] takes into account, in a proper and objective form, all the contributions to polarimetric purity, namely, the contributions to the linear and circular degrees of polarization of R as well as to the stability of the plane containing its polarization ellipse. Consequently, P3 D constitutes a natural representative of the degree of polarimetric purity. Some implications for the common convention for the concept of two-dimensional degree of polarization are also analyzed and discussed.

Medical-isotope supply hit by production problems

Science.gov (United States)

Gould, Paula

2008-10-01

A shortfall in the production of medical isotopes in Europe has forced hospitals to delay patient scans or offer alternative diagnostic tests. The problems began in August when all three nuclear reactors used to generate molybdenum-99, which then decays to form the key nuclear-imaging agent technetium-99, had to be unexpectedly shut down at the same time.

Recent achievements in Tc-99m radiopharmaceutical direct production by medical cyclotrons.

Science.gov (United States)

Boschi, Alessandra; Martini, Petra; Pasquali, Micol; Uccelli, Licia

2017-09-01

99m Tc is the most commonly used radionuclide in the field of diagnostic imaging, a noninvasive method intended to diagnose a disease, assess the disease state and monitor the effects of treatments. Annually, the use of 99m Tc, covers about 85% of nuclear medicine applications. This isotope releases gamma rays at about the same wavelength as conventional X-ray diagnostic equipment, and owing to its short half-life (t ½  = 6 h) is ideal for diagnostic nuclear imaging. A patient can be injected with a small amount of 99m Tc and within 24 h almost 94% of the injected radionuclide would have decayed and left the body, limiting the patient's radiation exposure. 99m Tc is usually supplied to hospitals through a 99 Mo/ 99m Tc radionuclide generator system where it is produced from the β decay of the parent nuclide 99 Mo (t ½  = 66 h), which is produced in nuclear reactors via neutron fission. Recently, the interruption of the global supply chain of reactor-produced 99 Mo, has forced the scientific community to investigate alternative production routes for 99m Tc. One solution was to consider cyclotron-based methods as potential replacement of reactor-based technology and the nuclear reaction 100 Mo(p,2n) 99m Tc emerged as the most worthwhile approach. This review reports some achievements about 99m Tc produced by medical cyclotrons. In particular, the available technologies for target design, the most efficient extraction and separation procedure developed for the purification of 99m Tc from the irradiated targets, the preparation of high purity 99m Tc radiopharmaceuticals and the first clinical studies carried out with cyclotron produced 99m Tc are described.

Accelerator Production of Isotopes for Medical Use

Science.gov (United States)

Lapi, Suzanne

2014-03-01

The increase in use of radioisotopes for medical imaging and therapy has led to the development of novel routes of isotope production. For example, the production and purification of longer-lived position emitting radiometals has been explored to allow for nuclear imaging agents based on peptides, antibodies and nanoparticles. These isotopes (64Cu, 89Zr, 86Y) are typically produced via irradiation of solid targets on smaller medical cyclotrons at dedicated facilities. Recently, isotope harvesting from heavy ion accelerator facilities has also been suggested. The Facility for Rare Isotope Beams (FRIB) will be a new national user facility for nuclear science to be completed in 2020. Radioisotopes could be produced by dedicated runs by primary users or may be collected synergistically from the water in cooling-loops for the primary beam dump that cycle the water at flow rates in excess of hundreds of gallons per minute. A liquid water target system for harvesting radioisotopes at the National Superconducting Cyclotron Laboratory (NSCL) was designed and constructed as the initial step in proof-of-principle experiments to harvest useful radioisotopes in this manner. This talk will provide an overview of isotope production using both dedicated machines and harvesting from larger accelerators typically used for nuclear physics. Funding from Department of Energy under DESC0007352 and DESC0006862.

Synthesis of high-purity Li{sub 8}ZrO{sub 6} powder by solid state reaction under hydrogen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Shin-mura, Kiyoto; Otani, Yu; Ogawa, Seiya [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Niwa, Eiki; Hashimoto, Takuya [Department of Physics, College of Humanities and Sciences, Nihon University, 3-8-1 Sakurajousui, Setagaya-ku, Tokyo 156-8550 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuchi, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Sasaki, Kazuya, E-mail: k_sasaki@tokai-u.ac.jp [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)

2016-11-01

Highlights: • A fine pure Li{sub 8}ZrO{sub 6} powder was synthesized by using Li{sub 2}CO{sub 3} and ZrO{sub 2} via a solid state reaction. • Influences on the purity of product powder, lattice defect, and crystal orientation were revealed. • The suitable synthesis conditions of the fine and high purity Li{sub 8}ZrO{sub 6} powder were found. • The reaction process of the synthesis of Li{sub 8}ZrO{sub 6} was estimated. - Abstract: Li{sub 8}ZrO{sub 6} contains a large amount of Li and has a significant potential as a tritium breeder. However, few syntheses of fine-grain, high-purity Li{sub 8}ZrO{sub 6} powder have been reported. In this study, a high-purity powder of Li{sub 8}ZrO{sub 6} was synthesized by solid state reaction under hydrogen atmosphere combined with an effective lithium source and a suitable initial Li:Zr molar ratio. Mixed powders of Li{sub 2}CO{sub 3} and ZrO{sub 2} were fired at around 630 °C in H{sub 2} for several hours and several firing cycles. The low firing temperature inhibited the vaporization of Li during the heating, so that excessive amounts of Li were not needed for the synthesis, and the Li:Zr ratio in the starting material was 10:1 (mol:mol). In this synthesis, Li{sub 2}O was generated via the decomposition of Li{sub 2}CO{sub 3} during firing in H{sub 2}, and reacted with ZrO{sub 2} to form Li{sub 6}Zr{sub 2}O{sub 7}, which reacted with itself to form Li{sub 8}ZrO{sub 6}.

Electrophoresis for the analysis of heparin purity and quality.

Science.gov (United States)

Volpi, Nicola; Maccari, Francesca; Suwan, Jiraporn; Linhardt, Robert J

2012-06-01

The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007-2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of important parameters on the irradiation of 124Xe, to improve the production of 123I with high purity using the Cyclone-30 cyclotron at IPEN-CNEN/SP

International Nuclear Information System (INIS)

Sumiya, Luiz Carlos do Amaral

2006-01-01

The development of diagnosis equipment and therapy procedures in nuclear medicine depends on the availability of commercial radioisotopes. IPEN is the most important institution that provides radioisotopes for national market. In order to achieve this function, IPEN had invested in the acquisition of a 30 MeV Cyclone-30 cyclotron to produce mainly 18 F, 67 Ga, 201 Tl and 123 I. The 123 I production is the aim of the present work. With the 123 I routine production data obtained by proton irradiation of Xe targets with an enrichment greater than 99.8%, it was possible to identify the important parameters that have direct influence on the production yield of high purity degree 123 I. Even though the methodology for the commercial production of 123 I, there are an scarcity of operational parameters data for this task. In this work the evaluated parameters were: 124 Xe pressure, proton beam quality, irradiation time, operational temperature of the irradiation system under irradiation, waiting time to obtain 123 I, temperature of washing solution and the impact of the internal Ni coating in the target. With the obtained results it was possible to modify the operational conditions for routine production and increasing the efficiency in about 30%. (author)

Isolation of high purity americium metal via distillation

Science.gov (United States)

Squires, Leah N.; King, James A.; Fielding, Randall S.; Lessing, Paul

2018-03-01

Pure americium metal is a crucial component for the fabrication of transmutation fuels. Unfortunately, americium in pure metal form is not available; however, a number of mixed metals and mixed oxides that include americium are available. In this manuscript a method is described to obtain high purity americium metal from a mixture of americium and neptunium metals with lead impurity via distillation.

Mode 2 Knowledge Production in the Context of Medical Research: A Call for Further Clarifications.

Science.gov (United States)

Soofi, Hojjat

2018-03-01

The traditional researcher-driven environment of medical knowledge production is losing its dominance with the expansion of, for instance, community-based participatory or participant-led medical research. Over the past few decades, sociologists of science have debated a shift in the production of knowledge from traditional discipline-based (Mode 1) to more socially embedded and transdisciplinary frameworks (Mode 2). Recently, scholars have tried to show the relevance of Mode 2 knowledge production to medical research. However, the existing literature lacks detailed clarifications on how a model of Mode 2 knowledge production can be constructed in the context of medical research. This paper calls for such further clarifications. As a heuristic means, the advocacy for a controversial experimental stem cell therapy (Stamina) is examined. It is discussed that the example cannot be considered a step towards Mode 2 medical knowledge production. Nonetheless, the example brings to the fore some complexities of medical knowledge production that need to be further examined including: (1) the shifting landscape of defining and addressing vulnerability of research participants, (2) the emerging overlap between research and practice, and (3) public health implications of revising the standard notions of quality control and accountability.

Recovery of high-purity metallic Pd from Pd(II)-sorbed biosorbents by incineration.

Science.gov (United States)

Won, Sung Wook; Lim, Areum; Yun, Yeoung-Sang

2013-06-01

This work reports a direct way to recover metallic palladium with high purity from Pd(II)-sorbed polyethylenimine-modified Corynebacterium glutamicum biosorbent using a combined method of biosorption and incineration. This study is focused on the incineration part which affects the purity of recovered Pd. The incineration temperature and the amount of Pd loaded on the biosorbent were considered as major factors in the incineration process, and their effects were examined. The results showed that both factors significantly affected the enhancement of the recovery efficiency and purity of the recovered Pd. SEM-EDX and XRD analyses were used to confirm that Pd phase existed in the ash. As a result, the recovered Pd was changed from PdO to zero-valent Pd as the incineration temperature was increased from 600 to 900°C. Almost 100% pure metallic Pd was recovered with recovery efficiency above 99.0% under the conditions of 900°C and 136.9 mg/g. Copyright © 2013 Elsevier Ltd. All rights reserved.

MIS High-Purity Plutonium Oxide Metal Oxidation Product TS707001 (SSR123): Final Report

Energy Technology Data Exchange (ETDEWEB)

Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Narlesky, Joshua Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Max A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carillo, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-08-09

A high-purity plutonium dioxide material from the Material Identification and Surveillance (MIS) Program inventory has been studied with regard to gas generation and corrosion in a storage environment. Sample TS707001 represents process plutonium oxides from several metal oxidation operations as well as impure and scrap plutonium from Hanford that are currently stored in 3013 containers. After calcination to 950°C, the material contained 86.98% plutonium with no major impurities. This study followed over time, the gas pressure of a sample with nominally 0.5 wt% water in a sealed container with an internal volume scaled to 1/500th of the volume of a 3013 container. Gas compositions were measured periodically over a six year period. The maximum observed gas pressure was 138 kPa. The increase over the initial pressure of 80 kPa was primarily due to generation of nitrogen and carbon dioxide gas in the first six months. Hydrogen and oxygen were minor components of the headspace gas. At the completion of the study, the internal components of the sealed container showed signs of corrosion, including pitting.

An INVAP perspective on the production of medical radioisotopes: past and present

International Nuclear Information System (INIS)

Salvatore, M.

2009-01-01

This presentation gives a perspective on medical radionuclide production methods from INVAP, Argentina. INVAP is a company headquartered in Argentina and is involved amongst other activities in nuclear, medical and scientific equipment. It describes INVAP's involvement in research reactor projects in a number of countries around the world. The paper describes a number of turn-key facilities for the production of radioisotopes for medicine, industry and research activities.

Purity of antidotal oxime HI-6 DMS as an active pharmaceutical ingredient for auto-injectors and infusions.

Science.gov (United States)

Bogan, Reinhard; Koller, Marianne; Klaubert, Bernd

2012-01-01

As reactivators of inhibited acetylcholinesterase, oximes are essential antidotes in poisoning by organophosphorus compounds. Due to its superior efficacy in cases of soman, cyclosarin, and sarin poisoning, the oxime HI-6 represents a promising option for an active pharmaceutical ingredient (API) in the further development of antidote therapy for nerve agent poisoning. Developmental lots of HI-6 DMS (dimethanesulfonate) provided by different manufacturers were examined with respect to their content and purity with a view to their future use as an API. There are distinct differences in the HI-6 content from three manufacturers. With respect to purity, gradual differences arise with the known synthetic by-products as well as with unknown accompanying compounds. It became apparent that in the case of a modified synthesis using protective groups, the proportion of some synthesis by-products decreases considerably. With one exception, they are thus below the reporting threshold for API in accordance with pertinent regulatory guidelines. In HI-6, an unknown impurity always occurs, whose percentage necessitates identification due to regulations. This unknown impurity, which has not been described so far, could be identified as an isomer. These findings supply data required for the description of pharmaceutical quality in accordance with module 3 of a Common Technical Document (CTD). They thus contribute to the marketing authorization of this substance as an API for auto-injectors and infusions. Copyright © 2012 John Wiley & Sons, Ltd.

High-purity germanium detection system for the in vivo measurement of americium and plutonium

International Nuclear Information System (INIS)

Tyree, W.H.; Falk, R.B.; Wood, C.B.; Liskey, R.W.

1976-01-01

A high-purity germanium (HPGe) array, photon-counting system has been developed for the Rocky Flats Plant Body-Counter Medical Facility. The newly improved system provides exceptional resolutions of low-energy X-ray and gamma-ray spectra associated with the in vivo deposition of plutonium and americium. Described are the operational parameters of the system and some qualitative results illustrating detector performance for the photon emissions produced from the decay of plutonium and americium between energy ranges from 10 to 100 kiloelectron volts. Since large amounts of data are easily generated with the system, data storage, analysis, and computer software developments continue to be an essential ingredient for processing spectral data obtained from the detectors. Absence of quantitative data is intentional. The primary concern of the study was to evaluate the effects of the various physical and electronic operational parameters before adding those related entirely to a human subject

Preservatives in Personal Hygiene and Cosmetic Products, Topical Medications, and Household Cleaners in Spain.

Science.gov (United States)

Pastor-Nieto, María Antonia; Alcántara-Nicolás, Francisco; Melgar-Molero, Virginia; Pérez-Mesonero, Raquel; Vergara-Sánchez, Aránzazu; Martín-Fuentes, Adriana; González-Muñoz, Patricia; de Eusebio-Murillo, Ester

2017-10-01

Preservatives are added to cosmetic, household cleaning, and other industrial products to prevent the growth of microorganisms. Unfortunately, exposure to these substances can cause sensitization. Between January and June 2015, we analyzed the ingredients of 2300 products commercially available in Spain to identify the frequency of a wide variety of preservatives in different product categories. We analyzed 1093 skin care and cosmetic products sold exclusively in pharmacies (dermocosmetics), 458 household cleaning and personal hygiene and cosmetic products sold in supermarkets, 636 topical medications, and 113 cosmetic products sold in a herbal shop. Phenoxyethanol, citric acid, sodium benzoate, and potassium sorbate were very common in all the cosmetic product categories. Parabens were present in 16.1% of dermocosmetic products, 14.45% of cosmetic products available in supermarkets, 0.88% of cosmetic products available in the herbal shop, 5.18% of topical medications, and in none of the cleaning products. Isothiazolinones were identified in 2.56% of dermocosmetic products, 18% of cosmetic products in supermarkets, 7.9% of cosmetic products in the herbal shop, 63.63% of household cleaners, and in none of the topical medications. Formaldehyde releasers were detected in 5.76% of dermocosmetic products, 6.42% of cosmetic products sold in supermarkets, 7.96% of cosmetic products sold in the herbal shop, 3.93% of topical medications, and 16.74% of household cleaners. Evaluation of the presence of preservatives in everyday products allows us to indirectly estimate exposure levels to each one. Measures restricting the use of the most problematic preservatives need to be strengthened. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

Energy Technology Data Exchange (ETDEWEB)

Tseng, Hui-Yu; Chen, Hsiao-Ping [National Chung Cheng University, Department of Chemistry and Biochemistry (China); Tang, Yi-Hsuan [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Chen, Hui-Ting [Kaohsiung Medical University, Department of Fragrance and Cosmetic Science (China); Kao, Chai-Lin, E-mail: clkao@kmu.edu.tw [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Wang, Shau-Chun, E-mail: chescw@ccu.edu.tw [National Chung Cheng University, Department of Chemistry and Biochemistry (China)

2016-03-15

Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract.

The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

International Nuclear Information System (INIS)

Tseng, Hui-Yu; Chen, Hsiao-Ping; Tang, Yi-Hsuan; Chen, Hui-Ting; Kao, Chai-Lin; Wang, Shau-Chun

2016-01-01

Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract

Evaluation of Radioisotope Production Process of 153Sm and 153Sm-EDTMP Radiopharmaceuticals

International Nuclear Information System (INIS)

Kadarisman; Sri Hastini; Yayan Tahyan; Abidin; Dadang Hafid; Enny Lestari

2007-01-01

Experiments on the process of 153 Sm radioisotope and labeling of 153 Sm-EDTMP radiopharmaceuticals were carried out. This experiments included preparation of Sm 2 O 3 target, dissolution of post irradiation, determination of radioactivity concentration of 153 Sm radioisotope, radionuclide purity, EDTMP labeling, determination of radiochemical purity and pH. In these experiments the total radioactivity 153 Sm product is round about 2845.83 mCi to 36963.31 mCi, or with the radioactivity concentration between 474 mCi/ml to 6160.55 mCi/ml in the SmCl 3 solution form, each its volume is 6.0 ml, and the samarium content is 5.76 mg/ml, and the radionuclide purity of 153 Sm is 100 %. All of the 153 Sm- EDTMP radiopharmaceuticals product are fulfilled requirements the radioactivity concentration, Sm content, radiochemical purity and pH. The radioactivity concentration of 153 Sm-EDTMP radiopharmaceuticals is 37.50 mCi/ml (minimum) to 283.50 mCi/ml (highest). The pH 7.5 were 8 products, and the rest are pH 8.5. Radiochemical purity of 153 Sm-EDTMP are round about 90.00 % to 99.44 %. (author)

Radiation sterilization of medical products in the Philippines

International Nuclear Information System (INIS)

Singson, C.; Carmona, C.; Guzman, Z. de; Barrun, W.; Lanuza, L.

1983-01-01

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. (author)

Radiation sterilization of medical products in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Singson, C; Carmona, C; Guzman, Z de; Barrun, W; Lanuza, L [Philippine Atomic Energy Commission, Diliman, Quezon City

1983-01-01

This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D/sub 10/ values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged.

Disgust sensitivity is primarily associated with purity-based moral judgments

NARCIS (Netherlands)

Wagemans, F.M.A.; Brandt, M.J.; Zeelenberg, M.

2018-01-01

Individual differences in disgust sensitivity are associated with a range of judgments and attitudes related to the moral domain. Some perspectives suggest that the association between disgust sensitivity and moral judgments will be equally strong across all moral domains (i.e., purity, authority,

Sorption techniques for production of high purity refractory metals

International Nuclear Information System (INIS)

Shatalov, V.V.; Peganov, V.A.; Logvinenko, I.A.; Molchanova, T.V.

2004-01-01

A consideration is given to potentialities of sorption processes tot provide a high quality of refractory metal and their alloys when using hydrometallurgical methods for raw material processing. The efficiency of application of ion exchange technology is shown for complex solutions reprocessing for various types of polymetallic raw materials, among them uranium ores, enriched concentrates of refractory metal ores, intermediate products, waste solutions. Based on investigation results on the behaviour of elements in process solutions and the mechanism of their sorption and elution, the process of pure chemical compounds production are developed which provide thereafter manufacturing compact metals. The flowsheets developed are mastered on a commercial scale [ru

Comprehensive spectral and instrumental approaches for the easy monitoring of features and purity of different carbon nanostructures for nanocomposite applications

International Nuclear Information System (INIS)

Boccaleri, Enrico; Arrais, Aldo; Frache, Alberto; Gianelli, Walter; Fino, Paolo; Camino, Giovanni

2006-01-01

A wide series of carbon nanostructures (ranging from fullerenes, through carbon nanotubes, up to carbon nanofibers) promise to change several fields in material science, but a real industrial implementation depends on their availability at reasonable prices with affordable and reproducible degrees of purity. In this study we propose simple instrumental approaches to efficiently characterize different commercial samples, particularly for qualitative evaluation of impurities, the discrimination of their respective spectral features and, when possible, for quantitative determination. We critically discuss information that researchers in the field of nanocomposite technology can achieve in this aim by spectral techniques such as Raman and FT-IR spectroscopy, thermo-gravimetrical analysis, mass spectrometry-hyphenated thermogravimetry, X-ray diffraction and energy dispersive spectroscopy. All these can be helpful, in applied research on material science, for a fast reliable monitoring of the actual purity of carbon products in both commercial and laboratory-produced samples as well as in composite materials

Recent advances in P/M-tantalum products

International Nuclear Information System (INIS)

Kumar, P.; Uhlenhut, H.

2001-01-01

The metallurgical grade tantalum powder is used for producing parts and mill products. Some of the key requirements include purity, physical characteristics (flow, fill density and compressibility) and interstitial contents. A process to produce 99.99 % pure tantalum powder with less than 150 ppm oxygen has been developed. This powder was consolidated into metallurgical products via conventional P/M processing; resulting products had high purity and low oxygen. It also retained fine grain-size and uniform properties inherent in P/M-derived products. In addition, the desired crystallographic texture was obtained by controlled thermo-mechanical processing (TMP) of the consolidated powder. Fully dense products of this powder were tested for various applications, such as deep drawing, sputtering, ballistics and capacitors. Critical functional requirements in these applications along with the results of evaluations are discussed. (author)

Effect of relative nanohole position on colour purity of ultrathin plasmonic subtractive colour filters

International Nuclear Information System (INIS)

Sun, L B; Hu, X L; Zhang, D X; Zeng, Beibei; Wang, L S; Yang, S M; Tai, R Z; Fecht, H J; Jiang, J Z

2015-01-01

Plasmonic subtractive color filters through patterning periodic nanostructures on ultrathin Ag films deposited on a glass substrate, exhibiting good durability, simple fabrication, and flexible color tunability, have attracted considerable attention due to their tremendous potential applications. While previous studies have mainly focused on their extraordinary physical mechanisms, color purity, which is another key parameter for high quality imaging applications, has been much less investigated. In this work, we demonstrate that the relative position of nanoholes patterned on ultrathin Ag films can largely affect the color purity of plasmonic subtractive color filters. The calculated results agree reasonably well with the experimental data, revealing that the purity of subtractive colors can be improved by changing the nanohole arrays from square lattice to triangular lattice without reducing transmission at visible frequencies. In addition, underlying mechanisms are clarified by systematically analyzing the dominant valley in transmission spectra. (paper)

Fabrication high-purity Fe nanochains with near theoretical limit value of saturation magnetization of bulk Fe

Energy Technology Data Exchange (ETDEWEB)

Bian, Erkang [Henan University, Key Laboratory for Special Functional Materials of Ministry of Education (China); Xu, Yanling [Henan University, The Audit Department (China); Lou, Shiyun, E-mail: lousy@henu.edu.cn [Henan University, Key Laboratory for Special Functional Materials of Ministry of Education (China); Fu, Yunlong, E-mail: yunlongfu@dns.sxnu.edu.cn [Shanxi Normal University, School of Chemistry and Material Science (China); Zhou, Shaomin, E-mail: smzhou@henu.edu.cn [Henan University, Key Laboratory for Special Functional Materials of Ministry of Education (China)

2016-11-15

High-yield purity chain-like one-dimensional nanostructures consisting of single crystal Fe nanoparticles have been produced by using solution dispersion approach. Room temperature magnetic measurement shows that the as-fabricated Fe nanochains are ferromagnetic with a high saturation magnetization (203 emu/g) whereas the nanoparticles are single magnetic domains, which indicate that the as-synthesized products have superparamagnetism behavior with the saturation magnetization of about 28 emu/g. Maybe this results from the directional alignment of the nanoparticles. The excellent characteristic may have led to the potential applications in spin filtering, high density magnetic recording, and nanosensors.

The Supply of Medical Radioisotopes. Market impacts of converting to low-enriched uranium targets for medical isotope production

International Nuclear Information System (INIS)

Westmacott, Chad; Cameron, Ron

2012-01-01

The reliable supply of molybdenum-99 ( 99 Mo) and its decay product, technetium-99m ( 99m Tc), is a vital component of modern medical diagnostic practices. At present, most of the global production of 99 Mo is from highly enriched uranium (HEU) targets. However, all major 99 Mo-producing countries have recently agreed to convert to using low-enriched uranium (LEU) targets to advance important non-proliferation goals, a decision that will have implications for the global supply chain of 99 Mo/ 99m Tc and the long-term supply reliability of these medical isotopes. This study provides the findings and analysis from an extensive examination of the 99 Mo/ 99m Tc supply chain by the OECD/NEA High-level Group on the Security of Supply of Medical Radioisotopes (HLG-MR). It presents a comprehensive evaluation of the potential impacts of converting to the use of LEU targets for 99 Mo production on the global 99 Mo/ 99m Tc market in terms of costs and available production capacity, and the corresponding implications for long-term supply reliability. In this context, the study also briefly discusses the need for policy action by governments in their efforts to ensure a stable and secure long-term supply of 99 Mo/ 99m Tc

Influence of solvents on the changes in structure, purity, and in vitro characteristics of green-synthesized ZnO nanoparticles from Costus igneus

Science.gov (United States)

Nandhini, G.; Suriyaprabha, R.; Maria Sheela Pauline, W.; Rajendran, V.; Aicher, Wilhelm Karl; Awitor, Oscar Komla

2018-05-01

The present study is intended to produce high-purity zinc oxide nanoparticles from the leaves of Costus igneus and zinc acetate precursor via sustainable methods by the tribulation with three different solvents (hot water, methanol, and acetone) for the extraction of plant compounds. While examining the physico-chemical characteristics of ZnO nanoparticles incurred by the catalysis of plant bioactive compounds extracted from different solvents, the hot water extract-based green synthesis process yields higher purity (99.89%) and smaller particle size (94 nm) than other solvents. The optimization of the solvents used for the green synthesis of nanoparticles renders key identification in appropriate extraction of bioactive compounds suitable for the nucleation/production of nanoparticles in addition to annealing temperature. The impregnable usage of ZnO nanoparticles in clinical applications is further confirmed based on the treatment of particles (1-10 mg ml-1) against Gram-positive (S. aureus and S. epidermis) and Gram-negative bacteria (E. coli and K. pneumoniae) with respect to their growth inhibition. An in-force growth inhibition against particular S. aureus and S. epidermis imparted by the low concentration of ZnO nanoparticles signifies the utilization and consumption of green-synthesized high-purity nanoparticles for therapeutic and cosmetic applications.

Almost purity for overconvergent Witt vectors

DEFF Research Database (Denmark)

Davis, Christopher James; Kedlaya, Kiran

2015-01-01

 . Here, we use almost purity to lift the finite étale extension of R[p−1]R[p−1] to a finite étale extension of rings of overconvergent Witt vectors. The point is that no hypothesis of p-adic completeness is needed; this result thus points towards potential global analogues of p  -adic Hodge theory....... As an illustration, we construct (φ,Γ)(φ,Γ)-modules associated with Artin Motives over QQ. The (φ,Γ)(φ,Γ)-modules we construct are defined over a base ring which seems well-suited to generalization to a more global setting; we plan to pursue such generalizations in later work....

Corrosion behavior of high purity Fe-Cr-Ni alloys in trans-passive condition

International Nuclear Information System (INIS)

Mayuzumi, Masami; Ohta, Jyoji; Kako, Kenji

1998-01-01

The corrosion behavior of high-purity (99.99%) Fe-Cr-Ni alloys was investigated in 13 N nitric acid with/without Ce 4+ ions to clarify the effect of impurities on the trans-passive corrosion of stainless steel. The following results were obtained. (1) Almost no intergranular corrosion was observed in the high-purity alloys, although the corrosion rate of the matrix region was nearly the same as that of a commercial stainless steel with the same Cr and Ni content. (2) Due to the improved intergranular corrosion resistance, the effect of the purification became significant in the corrosion condition with the grain-separation being predominant. (3) The high-purity alloys showed higher susceptivility to intergranular corrosion with aging treatment between 873 K and 1073 K. Although the sulfuric acid/copper sulfate test suggested the formation of Cr-depleted zones, a grain boundary micro-analysis using a FETEM with an EDX did not reveal any change in Cr content or impurity segregain along the grain boundaries. The mechanism of corrosion enhancement resulting from the aging treatment remains nuclear. (author)

Chemical purity using quantitative "1H-nuclear magnetic resonance: a hierarchical Bayesian approach for traceable calibrations

International Nuclear Information System (INIS)

Toman, Blaza; Nelson, Michael A.; Lippa, Katrice A.

2016-01-01

Chemical purity assessment using quantitative "1H-nuclear magnetic resonance spectroscopy is a method based on ratio references of mass and signal intensity of the analyte species to that of chemical standards of known purity. As such, it is an example of a calculation using a known measurement equation with multiple inputs. Though multiple samples are often analyzed during purity evaluations in order to assess measurement repeatability, the uncertainty evaluation must also account for contributions from inputs to the measurement equation. Furthermore, there may be other uncertainty components inherent in the experimental design, such as independent implementation of multiple calibration standards. As such, the uncertainty evaluation is not purely bottom up (based on the measurement equation) or top down (based on the experimental design), but inherently contains elements of both. This hybrid form of uncertainty analysis is readily implemented with Bayesian statistical analysis. In this article we describe this type of analysis in detail and illustrate it using data from an evaluation of chemical purity and its uncertainty for a folic acid material. (authors)

Characterization of a high-purity germanium detector for small-animal SPECT.

Science.gov (United States)

Johnson, Lindsay C; Campbell, Desmond L; Hull, Ethan L; Peterson, Todd E

2011-09-21

We present an initial evaluation of a mechanically cooled, high-purity germanium double-sided strip detector as a potential gamma camera for small-animal SPECT. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4.5 mm width with a 5 mm pitch. We found an energy resolution of 0.96% at 140 keV, an intrinsic efficiency of 43.3% at 122 keV and a FWHM spatial resolution of approximately 1.5 mm. We demonstrated depth-of-interaction estimation capability through comparison of pinhole acquisitions with a point source on and off axes. Finally, a flood-corrected flood image exhibited a strip-level uniformity of less than 1%. This high-purity germanium offers many desirable properties for small-animal SPECT.

Bone marrow-derived cells for cardiovascular cell therapy: an optimized GMP method based on low-density gradient improves cell purity and function.

Science.gov (United States)

Radrizzani, Marina; Lo Cicero, Viviana; Soncin, Sabrina; Bolis, Sara; Sürder, Daniel; Torre, Tiziano; Siclari, Francesco; Moccetti, Tiziano; Vassalli, Giuseppe; Turchetto, Lucia

2014-09-27

Cardiovascular cell therapy represents a promising field, with several approaches currently being tested. The advanced therapy medicinal product (ATMP) for the ongoing METHOD clinical study ("Bone marrow derived cell therapy in the stable phase of chronic ischemic heart disease") consists of fresh mononuclear cells (MNC) isolated from autologous bone marrow (BM) through density gradient centrifugation on standard Ficoll-Paque. Cells are tested for safety (sterility, endotoxin), identity/potency (cell count, CD45/CD34/CD133, viability) and purity (contaminant granulocytes and platelets). BM-MNC were isolated by density gradient centrifugation on Ficoll-Paque. The following process parameters were optimized throughout the study: gradient medium density; gradient centrifugation speed and duration; washing conditions. A new manufacturing method was set up, based on gradient centrifugation on low density Ficoll-Paque, followed by 2 washing steps, of which the second one at low speed. It led to significantly higher removal of contaminant granulocytes and platelets, improving product purity; the frequencies of CD34+ cells, CD133+ cells and functional hematopoietic and mesenchymal precursors were significantly increased. The methodological optimization described here resulted in a significant improvement of ATMP quality, a crucial issue to clinical applications in cardiovascular cell therapy.

Medical Isotope Production Analyses In KIPT Neutron Source Facility

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Yousry

2016-01-01

Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99 Mo is the parent isotope of 99m Tc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

Medical Isotope Production Analyses In KIPT Neutron Source Facility

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto [Argonne National Lab. (ANL), Argonne, IL (United States); Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-01-01

Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. ⁹⁹Mo is the parent isotope of ^99mTc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

Development of anabolic-androgenic steroids purity certified reference materials for anti-doping.

Science.gov (United States)

Quan, Can; Su, Fuhai; Wang, Haifeng; Li, Hongmei

2011-12-20

The need for certified reference materials (CRM) of anabolic-androgenic steroids reference materials was emphasized by the Beijing 2008 Olympic game as a tool to improve comparability, ensuring accuracy and traceability of analytical results for competing athletes. The China National Institute of Metrology (NIM) responded to the state request by providing seven anabolic-androgenic steroids (AAS) reference materials for Beijing Olympic anti-doping, GBW (E) 100086-GBW (E) 100092. This work describes the production of the series of AAS CRMs, according to ISO Guides 34 and 35 [1,2], which comprises the material processing, homogeneity and stability assessment, CRMs' characterization including moisture content, trace metal content. The AASs' purity values were assigned with collaborative study involved eight laboratories applying high resolution liquid chromatography-diode array detector (HPLC-DAD). Homogeneity of the AAS CRMs were determined by an in-house validated liquid chromatographic methodology. Potential degradation during storage was also investigated and a shelf-life based on this value was established. The certified values of CRMs were 99.76±0.079%, 99.76±0.25%, 99.63±0.09%, 99.67±0.11%, 98.82±0.56%, 96.30±0.39% and 99.71±0.49% (purity±expanded uncertainty with confidence level of 95%) for methyltestosterone, testosterone propionate, nandrolone, nandrolone 17-propionate, boldenone, trenbolone acetate and testosterone respectively. The certified values for all the studied AAS reference materials are traceable to the international system of units (SI). The CRMs developed were applied by 32 laboratory including sports organizations and analytical laboratories during the 2008 Olympic game for anti-doping control. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluation of medical isotope production with the accelerator production of tritium (APT) facility

International Nuclear Information System (INIS)

Benjamin, R.W.; Frey, G.D.; McLean, D.C., Jr; Spicer, K.M.; Davis, S.E.; Baron, S.; Frysinger, J.R.; Blanpied, G.; Adcock, D.

1997-01-01

The accelerator production of tritium (APT) facility, with its high beam current and high beam energy, would be an ideal supplier of radioisotopes for medical research, imaging, and therapy. By-product radioisotopes will be produced in the APT window and target cooling systems and in the tungsten target through spallation, neutron, and proton interactions. High intensity proton fluxes are potentially available at three different energies for the production of proton- rich radioisotopes. Isotope production targets can be inserted into the blanket for production of neutron-rich isotopes. Currently, the major production sources of radioisotopes are either aging or abroad, or both. The use of radionuclides in nuclear medicine is growing and changing, both in terms of the number of nuclear medicine procedures being performed and in the rapidly expanding range of procedures and radioisotopes used. A large and varied demand is forecast, and the APT would be an ideal facility to satisfy that demand

Preparation of high-purity zirconium dioxide from baddeleyite

International Nuclear Information System (INIS)

Voskobojnikov, N.B.; Skiba, G.S.

1996-01-01

Interaction of baddeleyite concentrate with calcium oxide and calcium chloride in the process of caking is studied. The influence of grain size on calcium zirconate formation is tested. Conditions for cake leaching by hydrochloric acid and zirconium(4) oxychloride purification from calcium and silicon compounds by recrystallization are reported. Zirconium dioxide corresponding to specifications (6-2 special purity) is obtained with a high (more than 90%) chemical yield. 9 refs., 1 tab

Wet routes of high purity BaTiO3 nanopowders

International Nuclear Information System (INIS)

Wang Liqiu; Liu Liang; Xue Dongfeng; Kang Hongmin; Liu Changhou

2007-01-01

High purity BaTiO 3 nanopowders were prepared in wet routes through stearic acid gel (SAG) and acetic acid gel (AAG) techniques, respectively. BaTiO 3 samples were characterized by X-ray diffraction, transmission electron microscope, Fourier transform infrared spectrometry, X-ray fluorescence spectrometry, and thermal gravimetric analysis. The present results indicate that both methods have a similar reaction process during calcination, while BaTiO 3 crystallites were initially formed at 550 deg. C by SAG and 800 deg. C by AAG. Both methods could produce BaTiO 3 powders with a cubic perovskite structure, while they had different grain size distributions within 25-50 nm for SAG and 50-80 nm for AAG. BaTiO 3 samples prepared by SAG had a lower agglomeration than those by AAG. SAG has shown many distinctive advantages in the preparation of high purity BaTiO 3 nanopowders, without Ba and Ti losses and hazardous wastes

Development of high purity large forgings for nuclear power plants

International Nuclear Information System (INIS)

Tanaka, Yasuhiko; Sato, Ikuo

2011-01-01

The recent increase in the size of energy plants has been supported by the development of manufacturing technology for high purity large forgings for the key components of the plant. To assure the reliability and performance of the large forgings, refining technology to make high purity steels, casting technology for gigantic ingots, forging technology to homogenize the material and consolidate porosity are essential, together with the required heat treatment and machining technologies. To meet these needs, the double degassing method to reduce impurities, multi-pouring methods to cast the gigantic ingots, vacuum carbon deoxidization, the warm forging process and related technologies have been developed and further improved. Furthermore, melting facilities including vacuum induction melting and electro slag re-melting furnaces have been installed. By using these technologies and equipment, large forgings have been manufactured and shipped to customers. These technologies have also been applied to the manufacture of austenitic steel vessel components of the fast breeder reactors and components for fusion experiments.

Development of high purity large forgings for nuclear power plants

Science.gov (United States)

Tanaka, Yasuhiko; Sato, Ikuo

2011-10-01

The recent increase in the size of energy plants has been supported by the development of manufacturing technology for high purity large forgings for the key components of the plant. To assure the reliability and performance of the large forgings, refining technology to make high purity steels, casting technology for gigantic ingots, forging technology to homogenize the material and consolidate porosity are essential, together with the required heat treatment and machining technologies. To meet these needs, the double degassing method to reduce impurities, multi-pouring methods to cast the gigantic ingots, vacuum carbon deoxidization, the warm forging process and related technologies have been developed and further improved. Furthermore, melting facilities including vacuum induction melting and electro slag re-melting furnaces have been installed. By using these technologies and equipment, large forgings have been manufactured and shipped to customers. These technologies have also been applied to the manufacture of austenitic steel vessel components of the fast breeder reactors and components for fusion experiments.

90Y production of high purity by electrochemical separation

International Nuclear Information System (INIS)

Alberti Ramírez, Alejandro; Serra Águila, Rolando; Morín Zorrilla, José Antonio; Pino Peraza, Madián; Soler Iglesias, Joel; Cruz Morales, Amed

2016-01-01

In this paper 90 Y is obtained without added carrier, by electrolytic separation from a solution in secular equilibrium Sr-Y and further purification in three cycles electrolytic automated, at constant current. The process productivity was 60-80 mCi (2220-2960 MBq). The long half-life of 90 Sr to be used by virtually indefinitely ensuring the stability of the raw material for generator operation, which helps sustainability and production stability. In 18 productions to date could be found to both content of 90 Sr equal to 0.110 ± 0.004 (k = 2) kBq / g by various methods, for their ability combination with DTPA, bifunctional chelate appropriate range of concentrations and even in the presence of trace metals, resulting in excellent characteristics for use as precursor in the preparation of therapeutic radiopharmaceuticals including radioimmunotherapy. The latter being a pure beta emitter with physical half-life, comparable to the time of capture and residence of many antibodies in tumors. The influence of Fe (III) was studied by the method of addition and concluded that only affects the performance of DTPA 90 Y marking if their presence is above a concentration of 0.018 mol / L. We show that the presence of other metals such as Pb (II), Zn (II) and Cu (II) also affects performance complexation

Impact of mentoring medical students on scholarly productivity.

Science.gov (United States)

Svider, Peter F; Husain, Qasim; Mauro, Kevin M; Folbe, Adam J; Baredes, Soly; Eloy, Jean Anderson

2014-02-01

Our objectives were to evaluate collaboration with medical students and other nondoctoral authors, and assess whether mentoring such students influences the academic productivity of senior authors. Six issues of the Laryngoscope and International Forum of Allergy & Rhinology (IFAR) were examined for the corresponding author of each manuscript, and whether any students were involved in authorship. The h-index of all corresponding authors was calculated using the Scopus database to compare the scholarly impact of authors collaborating with students and those collaborating exclusively with other physicians or doctoral-level researchers. Of 261 Laryngoscope manuscripts, 71.6% had exclusively physician or doctoral-level authors, 9.2% had "students" (nondoctoral-level authors) as first authors, and another 19.2% involved "student" authors. Corresponding values for IFAR manuscripts were 57.1%, 6.3%, and 36.5%. Corresponding authors who collaborated with students had higher scholarly impact, as measured by the h-index, than those collaborating exclusively with physicians and doctoral-level scientists in both journals. Collaboration with individuals who do not have doctoral-level degrees, presumably medical students, has a strong association with scholarly impact among researchers publishing in the Laryngoscope and IFAR. Research mentorship of medical students interested in otolaryngology may allow a physician-scientist to evaluate the students' effectiveness and functioning in a team setting, a critical component of success in residency training, and may have beneficial effects on research productivity for the senior author. © 2013 ARS-AAOA, LLC.

Creating high-purity angular-momentum-state Rydberg atoms by a pair of unipolar laser pulses

Science.gov (United States)

Xin, PeiPei; Cheng, Hong; Zhang, ShanShan; Wang, HanMu; Xu, ZiShan; Liu, HongPing

2018-04-01

We propose a method of producing high-purity angular-momentum-state Rydberg atoms by a pair of unipolar laser pulses. The first positive-polarity optical half-cycle pulse is used to prepare an excited-state wave packet while the second one is less intense, but with opposite polarity and time delayed, and is employed to drag back the escaping free electron and clip the shape of the bound Rydberg wave packet, selectively increasing or decreasing a fraction of the angular-momentum components. An intelligent choice of laser parameters such as phase and amplitude helps us to control the orbital-angular-momentum composition of an electron wave packet with more facility; thus, a specified angular-momentum state with high purity can be achieved. This scheme of producing high-purity angular-momentum-state Rydberg atoms has significant application in quantum-information processing.

Purity of potassium iodide necessary for its use in phasers

Energy Technology Data Exchange (ETDEWEB)

Sood, B R [Punjabi Univ., Patiala (India). Dept. of Physics

1981-08-16

The purity requirements in KI crystals are discussed necessary to have longer lifetimes of phonons for its use in phasers. The main contribution to the phonon scattering at low temperatures arises from the scattering by natural isotopes (/sup 39/K, /sup 40/K, /sup 41/K, /sup 127/I).

Improved methods to determine radionuclidic purity of F-18 compounds

DEFF Research Database (Denmark)

Jørgensen, Thomas; Micheelsen, Mille Ankerstjerne; Jensen, Mikael

2012-01-01

Current revisions of monographs for F-18 pharmaceuticals in the European Pharmacopoeia (Ph. Eur.) (Ph. Eur., 2011) call for a radionuclidic purity (RNP) of or better than 99.9%. However, the current method is not sufficient nor effective for testing this required RNP level. We present a theoretical...

Nuclear purity and the production of uranium (1962)

International Nuclear Information System (INIS)

Verte, P.

1962-01-01

When the production of 'nuclear grade' uranium is dealt with, it is difficult, the author of this study points out, to separate its chemical, technical, and economical bearings. While recalling the evolution of chemical processes in various countries and describing the technic of uranium manufacture in the plant of the French 'Commissariat a l'Energie Atomique' at Le Bouchet, the author outlines the effect of economical contingencies on the problems the chemists and engineer are faced with. The question of cost price is also considered here with particular attention. (author) [fr

Mesophase Formation Stabilizes High-purity Magic-sized Clusters

KAUST Repository

Nevers, Douglas R.; Williamson, Curtis B.; Savitzky, Benjamin H; Hadar, Ido; Banin, Uri; Kourkoutis, Lena F.; Hanrath, Tobias; Robinson, Richard D.

2018-01-01

Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward their nucleation and stabilization is an outstanding issue. In this work, we demonstrate that high concentration synthesis (1000 mM) promotes a well-defined reaction pathway to form high-purity MSCs (>99.9%). The MSCs are resistant to typical growth and dissolution processes. Based on insights from in-situ X-ray scattering analysis, we attribute this stability to the accompanying production of a large, hexagonal organic-inorganic mesophase (>100 nm grain size) that arrests growth of the MSCs and prevents NP growth. At intermediate concentrations (500 mM), the MSC mesophase forms, but is unstable, resulting in NP growth at the expense of the assemblies. These results provide an alternate explanation for the high stability of MSCs. Whereas the conventional mantra has been that the stability of MSCs derives from the precise arrangement of the inorganic structures (i.e., closed-shell atomic packing), we demonstrate that anisotropic clusters can also be stabilized by self-forming fibrous mesophase assemblies. At lower concentration (<200 mM or >16 acid-to-metal), MSCs are further destabilized and NPs formation dominates that of MSCs. Overall, the high concentration approach intensifies and showcases inherent concentration-dependent surfactant phase behavior that is not accessible in conventional (i.e., dilute) conditions. This work provides not only a robust method to synthesize, stabilize, and study identical MSC products, but also uncovers an underappreciated stabilizing interaction between surfactants and clusters.

Mesophase Formation Stabilizes High-purity Magic-sized Clusters

KAUST Repository

Nevers, Douglas R.

2018-01-27

Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward their nucleation and stabilization is an outstanding issue. In this work, we demonstrate that high concentration synthesis (1000 mM) promotes a well-defined reaction pathway to form high-purity MSCs (>99.9%). The MSCs are resistant to typical growth and dissolution processes. Based on insights from in-situ X-ray scattering analysis, we attribute this stability to the accompanying production of a large, hexagonal organic-inorganic mesophase (>100 nm grain size) that arrests growth of the MSCs and prevents NP growth. At intermediate concentrations (500 mM), the MSC mesophase forms, but is unstable, resulting in NP growth at the expense of the assemblies. These results provide an alternate explanation for the high stability of MSCs. Whereas the conventional mantra has been that the stability of MSCs derives from the precise arrangement of the inorganic structures (i.e., closed-shell atomic packing), we demonstrate that anisotropic clusters can also be stabilized by self-forming fibrous mesophase assemblies. At lower concentration (<200 mM or >16 acid-to-metal), MSCs are further destabilized and NPs formation dominates that of MSCs. Overall, the high concentration approach intensifies and showcases inherent concentration-dependent surfactant phase behavior that is not accessible in conventional (i.e., dilute) conditions. This work provides not only a robust method to synthesize, stabilize, and study identical MSC products, but also uncovers an underappreciated stabilizing interaction between surfactants and clusters.

505 Effective Medicated Abdomen Wrapper Best External Care for Lingering Diseases Unconventional Product for Vigorous Health

Institute of Scientific and Technical Information of China (English)

1993-01-01

505 Effective Medicated Abdomen Wrapper,a national patent product(patent num-ber 90202386.1),together with its serial products,has filled in the gaps in the field ofChina’s medical science and health care products.The development of the product wasbrought into line with the State Spark Programme by the State Commission for Science

The European Expression Of Interest For High Purity U-233 Materials

Energy Technology Data Exchange (ETDEWEB)

Giaquinto, Joseph M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Younkin, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-04-01

The purpose of this letter report is to document the response for an Expression of Interest (EOI) sent to the European Safeguards and research and development (R&D) scientific communities for the distribution of small amounts of high purity ²³³U materials for use in safeguards, nonproliferation, and basic R&D in the nuclear disciplines. The intent for the EOI was to gauge the level of international interest for these materials from government and research institutions with programmatic missions in the nuclear security or nuclear R&D arena. The information contained herein is intended to provide information to assist key decision makers in DOE as to the ultimate disposition path for the high purity materials currently being recovered at Oak Ridge National Laboratory (ORNL) and only those items for which there is no United States (U.S.) sponsor identified.

Use of unmanned aerial vehicles for medical product transport.

Science.gov (United States)

Thiels, Cornelius A; Aho, Johnathon M; Zietlow, Scott P; Jenkins, Donald H

2015-01-01

Advances in technology and decreasing costs have led to an increased use of unmanned aerial vehicles (UAVs) by the military and civilian sectors. The use of UAVs in commerce is restricted by US Federal Aviation Administration (FAA) regulations, but the FAA is drafting new regulations that are expected to expand commercial applications. Currently, the transportation of medical goods in times of critical need is limited to wheeled motor vehicles and manned aircraft, options that can be costly and slow. This article explores the demand for, feasibility of, and risks associated with the use of UAVs to deliver medical products, including blood derivatives and pharmaceuticals, to hospitals, mass casualty scenes, and offshore vessels in times of critical demand. Copyright © 2015 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Influence of moisture and hydrogen purity of the reliability of powerful electric machines

International Nuclear Information System (INIS)

Vigovs'kij, O.V.; Khvalyin, D.Yi.; Mistets'kij, V.A.

2017-01-01

It is shown that today the turbo generators with hydrogen-water cooling system is most unreliable technical equipment of Ukrainian nuclear power plants. On the one hand, hydrogen has several advantages over other coolers; on the other hand, the presence of hydrogen in the turbo generators systems carries the danger of engine rooms of power plants. It is also shown that the water and oxygen are main hazardous impurities in hydrogen, and zone of generator shaft compaction is the most responsible zone with high concentration of water. From the analysis was found that increasing of hydrogen purity reduces the mechanical losses and the change in total losses depending on the hydrogen purity has a linear nature. For example, with an increase the hydrogen purity from 0,1203 to 0,09 the loss in turbo generator rotor can be reduced by nearly 500 kW, which is about 25 % at a pressure of 0,5 MPa. The possibility of using metal hydrides to ensure purity, purification and hydrogen sorption was looked. The most practical value is for such hydrides as LaNi5Hx, FeTiHx, ZrNiHx. The main advantage the metal hydrides method of purification is a significant reduction in the number of purification stages. It was shown that the use of a thermoelectric gas dryer will reduce the total consumption of technological gases, that are removed from nuclear power plants, by 2,3 - 2,4 times due to a decrease in 5,0 - 6,0 times their absolute humidity, and decrease by 5, 0 times the activity of gases due to an increase in their exposure time in the decrease activity installation. All this suggests that the creation a hydrogen humidity monitoring system in the exploited turbo generator will solve the problem of objective control of hydrogen purity with further computerization and accumulation the information. Using a drainage or purification system of hydrogen, reducing the temperature and humidity of the cooling gas, can increase the reliability of operation the turbo generators and significantly

Field Safety Notes in Product Problems of Medical Devices for Use in Pulmonology.

Science.gov (United States)

Hannig, Jürgen; Siekmeier, Rüdiger

2015-01-01

The current European system for medical devices is governed by three EC directives: the Medical Device Directive 93/42/EEC, the In-Vitro Diagnostic Directive 98/79/EC and the Active Implantable Medical Device Directive 90/385/EEC and regulates marketing and post-market surveillance of medical devices in the European Economic Area. In cases of incidents and field safety corrective actions (FSCA) manufacturers have to inform the responsible Competent Authority, which is the Federal Institute for Drugs and Medical Devices (BfArM) and the public by field safety notices (FSN). In this study we analyzed FSN of medical devices exclusively serving for diagnostics or treatment in pulmonology (e.g. nebulizers, oxygen concentrators, pulse oximeters, lung function analyzers, and non-active devices for treatment). FSCA and FSN publicized by BfArM in 2005-2013 were analyzed in respect to the MEDDEV 2.12-1 rev 8. In total 41 FSCA were publicized for the included products. German and English FSN were found in 36/35 cases, respectively. FSN were clearly characterized as FSN in 22/20 cases and declaration of the type of action was found in 27/26 cases, respectively. Product names were provided in all cases. Lot numbers or other information for product characterization were available in 7/8 and 26/24 cases, respectively. Detailed information regarding FSCA and product malfunction were found in 27/33 and 36/35 cases, respectively. Information on product related risks with previous use of the affected product was provided in 24/23 cases. In 34/34 cases manufacturers provided information to mitigate product related risks. Requests to pass FSN to persons needing awareness were found in 10/14 cases. Contact data were provided in 30/30 cases. Confirmation that the Competent Authority was informed was found in 12/14 cases and in 19/18 cases a customer confirmation was included. The obtained data suggest that there is an increasing annual number of FSCA and most FSN fulfill the criteria of

Experimental implementation and proof of principle for a radionuclidic purity test solely based on half-life measurement

DEFF Research Database (Denmark)

Jørgensen, Thomas; Jensen, Mikael

2016-01-01

have developed an GUI application for use as an easy and automated test tool in the production procedure.The test results show that this method fully complies with the requirements in the European Pharmacopoeia (Eur. Ph.) for RNP of FDG and F-18 Sodium Fluoride. (C) 2015 Elsevier Ltd. All rights......In this paper we present the results of an experimental implementation of the method (Jorgensen et al., 2012) for testing the radionuclidic purity (RNP) of F-18 compounds.The overall limitations of the experimental methods and their possible impacts on RNP detectability have been identified. We...

Medical use of cannabis products: Lessons to be learned from Israel and Canada.

Science.gov (United States)

Ablin, J; Ste-Marie, P A; Schäfer, M; Häuser, W; Fitzcharles, M-A

2016-02-01

The German government intends to reduce the barriers for the medical use of cannabis products. A discussion on the indications and contraindications of the medical use of cannabis and on the changes of the regulatory framework has already begun in Germany. It is useful to draw from the experiences of other countries with a more liberal medical use of cannabis. The Israeli and Canadian experience is outlined by physicians who have been charged with expertise on the medical use of cannabis by their jurisdiction. In Israel, only the plant-based cannabinoid nabiximol (mixture of tetrahydrocannabinol/cannabidiol) can be prescribed for spasticity/chronic pain in multiple sclerosis and for cancer pain. The costs of nabiximole are reimbursed by some, but not by all health maintenance organizations. The medical use of marijuana is permitted; however, it is strictly regulated by the government. Selected companies are allowed to produce marijuana for medical use, and only certain physicians are licensed to prescribe marijuana as a therapeutic drug for specific indications such as chronic neuropathic, and cancer pain, inflammatory bowel diseases, or posttraumatic stress disorder if conventional treatments have failed. The costs of marijuana are not reimbursed by health insurance companies. In Canada, synthetic cannabinoids and the plant-based (nabiximol) are licensed for neuropathic and cancer pain, HIV-related anorexia and chemotherapy-associate nausea. The costs of these synthetic cannabinoids are covered by health insurance companies. The medical use of marijuana as a treatment option is allowed for individual patients suffering from any medical condition when authorized by a medical practitioner or nurse. Licensed producers are the only source for patients to newly access medical cannabis, although those with previous permission to grow may continue cultivation at the present time. The costs of marijuana are not reimbursed by health insurance companies. There are multiple

Extending the product variety at ROMAG-PROD Heavy Water Plant

International Nuclear Information System (INIS)

Preda, M.; Patrascu, M.; Achimescu, D.; Stroia, A.

2004-01-01

separation factor and high vaporization heat of water; the isotopic purity would be upmost 97% due to the competition between the isotopic species present in the process; the yield would be limited by the amount of heavy oxygen isotopes existing in the produced heavy water. More thorough studies are underway. The second method considered is the oxygen isotope separation by cryogenic distillation of the oxygen. The procedure presents several advantages although it was not applied so far at an industrial scale: - it makes use as raw material of the oxygen produced by the air-nitrogen installation of the plant which is currently released into the atmosphere; the production cost is rather low due to the low energy consumption in the separation process by cryogenic distillation as compared with the water distillation; the yield of 18 O is high and also high is the isotopic purity (99%); at the same time one obtain concentrates in 17 O which is hard to separate by water distillation, while large amounts of 16 O of 99.99% purity result as a by-product highly-value for medical uses. In conclusion, having in view the availability of the raw materials, utilities. production facilities and the high-skilled personnel at ROMAG-PROD Heavy Water Plant on one hand and the raising world demand of 18 O on the other hand, establishing such an oxygen isotopic separation unit is entirely justified and profitable

Solid targets for 99mTc production on medical cyclotrons

International Nuclear Information System (INIS)

Hanemaayer, V.; Buckley, K.R.; Klug, J.; Ruth, T.J.; Schaffer, P.; Zeisler, S.K.; Benard, F.; Kovacs, M.; Leon, C.

2014-01-01

Recent disruptions in the molybdenum-technetium generator supply chain prompted a review of non-reactor based production methods for both 99 Mo and 99m Tc. Small medical cyclotrons (E p ∼ 16-24 MeV) are capable of producing Curie quantities of 99m Tc from isotopically enriched 100 Mo using the 100 Mo(p,2n) 99m Tc reaction. Unlike most other metallic target materials for routine production of medical radioisotopes, molybdenum cannot be deposited by reductive electroplating from aqueous salt solutions. To overcome this issue, we developed a new process for solid molybdenum targets based on the electrophoretic deposition of fine 100 Mo powder onto a tantalum plate, followed by high temperature sintering. The targets obtained were mechanically robust and thermally stable when irradiated with protons at high power density. (author)

Preparation of uranium-plutonium mixed nitride pellets with high purity

International Nuclear Information System (INIS)

Arai, Yasuo; Shiozawa, Ken-ichi; Ohmichi, Toshihiko

1992-01-01

Uranium-plutonium mixed nitride pellets have been prepared in the gloveboxes with high purity Ar gas atmosphere. Carbothermic reduction of the oxides in N 2 -H 2 mixed gas stream was adopted for synthesizing mixed nitride. Sintering was carried out in various conditions and the effect on the pellet characteristics was investigated. (author)

Comparison of different thin layer detection techniques to determine the radiochemical purity of radiopharmaceuticals

International Nuclear Information System (INIS)

Hammermaier, A.; Reich, E.; Boegl, W.

1985-01-01

Ten radiopharmaceuticals frequently used in clinical treatment were examined as to their radiochemical purity by paper and thin layer chromatography or electrophoresis, respectively. It is known that radiochemical impurities may result in an unnecessary exposure of the patients to be examined. Other than determining the radiochemical purity of several radiopharmaceuticals, a comparison of the different measuring methods of distributing activity on radiochromatograms or electropherograms is intended by this study. For this, the activity distribution in the developed radiochromatograms was assessed by four different measuring methods (TLC-linear analyzer, TLC-scanner with NaI(Tl) detector, TLC-scanner with gas flow counter and NaI(Tl) well-typ counter). As shown by the above analysis, only the TLC-linear analyzer and the NaI(Tl) well-typ counter (measurement of chromatograms or electropherograms cut into strips) are generally suitable methods for determining the radiochemical purity of radiochemicals, the TLC-scanner with gas flow counter is usable in most cases, while TLC-scanner with NaI(Tl) detector is yielding unsatisfactory results. (orig.) [de

Effect of the microstructure on electrical properties of high-purity germanium

Science.gov (United States)

Podkopaev, O. I.; Shimanskii, A. F.; Molotkovskaya, N. O.; Kulakovskaya, T. V.

2013-05-01

The interrelation between the electrical properties and the microstructure of high-purity germanium crystals has been revealed. The electrical conductivity of polycrystalline samples increases and the life-time of nonequilibrium charge carriers in them decreases with a decrease in the crystallite sizes.

Production and quality control of 66 Ga as a PET radioisotope

International Nuclear Information System (INIS)

Rowshanfarzad, P.; Jalilian, A. R.; Akhlaghi, M.; Sabet, M.

2004-01-01

Background: 66 Ga (t 1/2 =9.49 h, β + : 4.153 MeV, γ: 511, 834, 1039, 2752 keV) has a wide range of applications in different fields of medical sciences. Production of 66 Ga became one of our main interests, according to its increasing applications in nuclear medicine, particularly in PET imaging. Materials and Methods: 66 Zn (p,n) 66 Ga reaction was determined as the best choice for the production of 66 Ga, according to the present facilities and conditions. The bombardment was performed by 15 MeV protons in Cyclone 30-IBA accelerator with a current intensity of 180 μA for 67 min. ALICE nuclear code and SRIM nuclear program were used to determine the optimum energy and target thickness. Targets were prepared by electroplating of 66 Zn (>95%) on a copper backing. Chemical processing was performed by a no carrier added method consisting of ion exchange chromatography and liquid-liquid extraction. Anion exchange chromatography was used for the recovery of target material. Quality control of the product was carried out in two steps of chemical and radionuclidic purity control. Results: the activity of 66 Ga was 2.41 Ci at the end of bombardment and the production yield was 12.04 mCi/μAh. The chemical separation yield was 93% and the yield of chemical recovery of the target material was 97%. Quality control tests showed a radionuclidic purity of more than 97% and the amounts of chemical impurities were in accordance with standard levels. Discussion: Our production yield was comparable with previous reports given in the literature. The chemical separation method used in this research was simple and brought up acceptable results. So, this process can be considered as one of the best choices for the production of 66 Ga

78 FR 27971 - Dental Products Panel of the Medical Devices Advisory Committee; Notice of Meeting

Science.gov (United States)

2013-05-13

...] Dental Products Panel of the Medical Devices Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Dental Products Panel of the Medical Devices Advisory Committee. General Function of the Committee: To... regulatory classification for dental devices known as Endosseous Dental Implants (Blade-form), one of the...

Some aspects of ICP-AES analysis of high purity rare earths

International Nuclear Information System (INIS)

Murty, P.S.; Biswas, S.S.

1991-01-01

Inductively coupled plasma atomic emission spectrometry (ICP-AES) is a technique capable of giving high sensitivity in trace elemental analysis. While the technique possesses high sensitivity, it lacks high selectivity. Selectivity is important where substances emitting complex spectra are to be analysed for trace elements. Rare earths emit highly complex spectra in a plasma source and the determination of adjacent rare earths in a high purity rare earth matrix, with high sensitivity, is not possible due to the inadequate selectivity of ICP-AES. One approach that has yielded reasonably good spectral selectivity in the high purity rare earth analysis by ICP-AES is by employing a combination of wavelength modulation techniques and high resolution echelle grating. However, it was found that by using a high resolution monochromator senstitivities either comparable to or better than those reported by the wavelength modulation technique could be obtained. (author). 2 refs., 2 figs., 2 tabs

Determination of radiochemistry purity and pH of radiopharmaceutical in Northeast nuclear medicine services

International Nuclear Information System (INIS)

Andrade, Wellington; Santos, Poliane; Lima, Fernando de Andrade; Lima, Fabiana Farias de

2013-01-01

The radiopharmaceutical is a chemical compound associated with a radionuclide, which is selected so that meets the need cf diagnosis and capable of producing quality images. Drugs labeled with 99m Tc radionuclide kits consist of lyophilized, and be handled by the nuclear medicine services (NMS) must pass tests as the resolution of ANVISA (RDC 38) published in 2008. Among these tests are those of radiochemical purity and pH determination. This study evaluated the radiochemical purity of radiopharmaceuticals and pH SMN manipulated in the Northeast. The radiochemical purity (RCP) was determined by thin layer chromatography, which were used Whatman ® and silica gel, with dimensions of 1 x 10 cm, as stationary phase, and solvents indicated in the inserts of manufacturers. The chromatographic strips were placed in sealed containers so as not to touch the walls thereof. After the chromatographic run, the tape was cut every centimeter and the activities determined in doses of each calibrator NMS. The pH of the radiopharmaceutical was assessed through the use of universal pH paper (Merck®) and obtained staining compared with its color scale. The results showed (hat 82.6% and 100% of the radiopharmaceuticals of the samples were within the limits recommended by international pharmacopoeias for radiochemical purity and pl-l, respectively. There is then the need to include in routine tests indicated SMN by ANVISA. Well, they can detect possible problems in the marking of radiopharmaceuticals administered to the patient and avoid inappropriate material. (author)

High-purity Cu nanocrystal synthesis by a dynamic decomposition method

Science.gov (United States)

Jian, Xian; Cao, Yu; Chen, Guozhang; Wang, Chao; Tang, Hui; Yin, Liangjun; Luan, Chunhong; Liang, Yinglin; Jiang, Jing; Wu, Sixin; Zeng, Qing; Wang, Fei; Zhang, Chengui

2014-12-01

Cu nanocrystals are applied extensively in several fields, particularly in the microelectron, sensor, and catalysis. The catalytic behavior of Cu nanocrystals depends mainly on the structure and particle size. In this work, formation of high-purity Cu nanocrystals is studied using a common chemical vapor deposition precursor of cupric tartrate. This process is investigated through a combined experimental and computational approach. The decomposition kinetics is researched via differential scanning calorimetry and thermogravimetric analysis using Flynn-Wall-Ozawa, Kissinger, and Starink methods. The growth was found to be influenced by the factors of reaction temperature, protective gas, and time. And microstructural and thermal characterizations were performed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. Decomposition of cupric tartrate at different temperatures was simulated by density functional theory calculations under the generalized gradient approximation. High crystalline Cu nanocrystals without floccules were obtained from thermal decomposition of cupric tartrate at 271°C for 8 h under Ar. This general approach paves a way to controllable synthesis of Cu nanocrystals with high purity.

Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization

Energy Technology Data Exchange (ETDEWEB)

Alvarez-Vasco, Carlos; Ma, Ruoshui; Quintero, Melissa; Guo, Mond; Geleynse, Scott; Ramasamy, Karthikeyan K.; Wolcott, Michael; Zhang, Xiao

2016-01-01

This paper reports a new method of applying Deep Eutectic Solvents (DES) for extracting lignin from woody biomass with high yield and high purity. DES mixtures prepared from Choline Chloride (ChCl) and four hydrogen-bond donors–acetic acid, lactic acid, levulinic acid and glycerol–were evaluated for treatment of hardwood (poplar) and softwood (D. fir). It was found that these DES treatments can selectively extract a significant amount of lignin from wood with high yields: 78% from poplar and 58% from D. fir. The extracted lignin has high purity (95%) with unique structural properties. We discover that DES can selectively cleave ether linkages in wood lignin and facilitate lignin removal from wood. The mechanism of DES cleavage of ether bonds between phenylpropane units was investigated. The results from this study demonstrate that DES is a promising solvent for wood delignification and the production of a new source of lignin with promising potential applications.

Direct production of ^99mTc using a small medical cyclotron

Energy Technology Data Exchange (ETDEWEB)

Lapi, Suzanne [Washington Univ., St. Louis, MO (United States)

2017-10-03

This project describes an investigation towards the production of ^99mTc with a small medical cyclotron. This endeavor addresses the current urgent problem of availability of ^99mTc due to the ongoing production reactor failures and the upcoming Canadian reactor shut down. Currently, ^99mTc is produced via nuclear fission using highly enriched uranium which is a concern due to nuclear proliferation risks. In addition to this, the United States is dependent solely on currently unreliable foreign sources of this important medical isotope. Clearly, a need exists to probe alternative production routes of ^99mTc. In the first year, this project measured cross-sections and production yields of potential pathways to ^99mTc and associated radionuclidic impurities produced via these pathways using a small 15 MeV medical cyclotron. During the second and third years target systems for the production of ^99mTc via the most promising reaction routes were developed and separation techniques for the isolation of ^99mTc from the irradiated target material will be investigated. Systems for the recycling of the enriched target isotopes as well as automated target processing systems were examined in years four and five. This project has the potential to alleviate some of the current crisis in the medical community by developing a technique to produce ^99mTc on location at a university hospital. This technology will be applicable at many other sites in the United States as many other similar, low energy (<20 MeV) cyclotrons (currently used for a few hours per day for the production of [¹⁸F]fluorodeoxyglucose) are available for production of ^99mTc though this method, thus leading to job creation and preservation.

High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

International Nuclear Information System (INIS)

Alexiev, D.; Butcher, K.S.A.

1991-11-01

Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and γ-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241 Am at 40 deg C. and the higher gamma energies of 235 U at -80 deg C. 15 refs., 1 tab., 6 figs

Production of beryllium oxide of nuclear purity from beryl

Energy Technology Data Exchange (ETDEWEB)

Copat, A; Sood, S P

1984-01-01

Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740/sup 0/C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide

Production of beryllium oxide of nuclear purity from beryl

International Nuclear Information System (INIS)

Copat, A.; Sood, S.P.

1983-01-01

Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740 0 C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide (Author) [pt

A novel approach to collaborative product development in the medical-equipment industry

OpenAIRE

Tseng, Kevin C; Chien-Lung, Hsu

2013-01-01

In this study, we summarise the requirements for collaborative product development based on our investigation of the differences in the resources and tools that are needed for the various stages of collaborative product development and the needs of system users during these various stages. We proposed a user-oriented approach of collaborative product development for medical equipment and designed a collaborative product development system with the required functionalities to satisfy different...

The production of iodine-123 on the Harwell variable energy cyclotron

International Nuclear Information System (INIS)

Cuninghame, J.G.; Hill, J.I.S.; Nichols, A.L.; Taylor, N.K.

1978-01-01

123 I has often been called the isotope of choice for dynamic body function studies in nuclear medicine. There has therefore, been a keen interest in the possibility of regular supply of high purity 123 I produced by the Harwell Variable Energy Cyclotron (VEC) and Synchrocyclotron (SC). This report describes a three year research and development programme on the VEC which has resulted in a method for the safe and reliable large scale production of 123 I by irradiation of di-iodomethane with 58 MeV protons. The quality of the product, and the medical trials which have been carried out with it, are also discussed. The processing and handling of the hundreds of millicuries produced during a run presents serious handling problems. These have been solved and the methods and equipment developed are described. (author)

State-of-the-art in analytical characterization of high purity solid ...

Indian Academy of Sciences (India)

Facilities and some results of several spectroscopic methods which have potential applications in the field of analysis of solid high purity substances and which have been elaborated in Russia, will be discussed in this paper. Laser nondispersive atomic fluorescence method with glow discharge cathode sputtering atomiser, ...

Preliminary Determination of Activation Products for a Varian Truebeam Linear Accelerator.

Science.gov (United States)

Waller, Edward; Ram, Rohan; Steadman, Ian

2017-09-01

Medical linear accelerators used to treat various forms of cancers are operated at a number of different energies. A by-product of the high-energy photons produced by accelerators is activation of components within the machine itself and its surrounding bunker. The activation products pose radiological and regulatory challenges during the operation of the accelerator as well as when it is time for final decommissioning. The Varian TrueBeam is a new state-of-the-art linear accelerator now operating in the Canadian market. There is currently limited information on the production of its activation products and the resulting impacts on operation and decommissioning. In this paper, activation products in the Varian TrueBeam accelerator are experimentally determined by performing gamma spectroscopy using a portable high purity germanium detector. A total of 10 isotopes are identified for the conditions tested, which include Na, Al, Mn, Ni, Cu, Cu, Br, Sb, Sb, W. The half-lives of these isotopes range from 2.3 min to 60.2 d. These preliminary results indicate that a decommissioning case similar to other radiotherapy accelerators can be made.

Purity, adulteration and price of drugs bought on-line versus off-line in the Netherlands.

Science.gov (United States)

van der Gouwe, Daan; Brunt, Tibor M; van Laar, Margriet; van der Pol, Peggy

2017-04-01

On-line drug markets flourish and consumers have high expectations of on-line quality and drug value. The aim of this study was to (i) describe on-line drug purchases and (ii) compare on-line with off-line purchased drugs regarding purity, adulteration and price. Comparison of laboratory analyses of 32 663 drug consumer samples (stimulants and hallucinogens) purchased between January 2013 and January 2016, 928 of which were bought on-line. The Netherlands. Primary outcome measures were (i) the percentage of samples purchased on-line and (ii) the chemical purity of powders (or dosage per tablet); adulteration; and the price per gram, blotter or tablet of drugs bought on-line compared with drugs bought off-line. The proportion of drug samples purchased on-line increased from 1.4% in 2013 to 4.1% in 2015. The frequency varied widely, from a maximum of 6% for controlled, traditional substances [ecstasy tablets, 3,4-methylenedioxy-methamphetamine (MDMA) powder, amphetamine powder, cocaine powder, 4-bromo-2,5-dimethoxyphenethylamine (2C-B) and lysergic acid diethylamide (LSD)] to more than a third for new psychoactive substances (NPS) [4-fluoroamphetamine (4-FA), 5/6-(2-aminopropyl)benzofuran (5/6-APB) and methoxetamine (MXE)]. There were no large differences in drug purity, yet small but statistically significant differences were found for 4-FA (on-line 59% versus off-line 52% purity for 4-FA on average, P = 0.001), MDMA powders (45 versus 61% purity for MDMA, P = 0.02), 2C-B tablets (21 versus 10 mg 2C-B/tablet dosage, P = 0.49) and ecstasy tablets (131 versus 121 mg MDMA/tablet dosage, P = 0.05). The proportion of adulterated samples purchased on-line and off-line did not differ, except for 4-FA powder, being less adulterated on-line (χ 2  = 8.3; P < 0.02). Drug prices were mainly higher on-line, ranging for various drugs from 10 to 23% higher than that of drugs purchased off-line (six of 10 substances: P < 0.05). Dutch drug users increasingly

Target-fueled nuclear reactor for medical isotope production

Science.gov (United States)

Coats, Richard L.; Parma, Edward J.

2017-06-27

A small, low-enriched, passively safe, low-power nuclear reactor comprises a core of target and fuel pins that can be processed to produce the medical isotope .sup.99Mo and other fission product isotopes. The fuel for the reactor and the targets for the .sup.99Mo production are the same. The fuel can be low enriched uranium oxide, enriched to less than 20% .sup.235U. The reactor power level can be 1 to 2 MW. The reactor is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days.

Aspects of 6-[18F]fluoro-L-DOPA preparation: precursor synthesis, preparative HPLC purification and determination of radiochemical purity

International Nuclear Information System (INIS)

Fuechtner, F.; Angelberger, P.; Kvaternik, H.; Hammerschmidt, F.; Simovc, B. Peric; Steinbach, J.

2002-01-01

A modified method for the synthesis of the intermediate product N-Boc-3,4-di(Boc-O)-6-iodo-L-phenylalanine ethyl ester of the [ 18 F]FDOPA precursor preparation was developed. With the application of bis-(trifluoroacetoxy)-iodobenzene for the iodination step with elemental iodine the yield of the intermediate can be increased from 12% to 50-60%. By replacing silica-gel-based RP HPLC column by a polymer-based column for semi-preparative purification of [ 18 F]FDOPA from the reaction mixture the radiochemical purity of the final product can be increased up to >99%. For the determination of the radiochemical impurity [ 18 F]fluoride a HPLC method using a column with polymer-based RP material was introduced

Obtaining high purity silica from rice hulls

Directory of Open Access Journals (Sweden)

José da Silva Júnior

2010-01-01

Full Text Available Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR, powder x-ray diffraction (XRD, x-ray fluorescence (XRF, scanning electron microscopy (SEM, particle size analysis by laser diffraction (LPSA and thermal analysis.

Neutron activation analysis of high-purity zinc

International Nuclear Information System (INIS)

Khodzhamberdyeva, A.A.; Usmanova, M.M.; Gil'bert, Eh.N.; Ivanov, I.M.; Yankovskaya, T.A.; Kholyavko, E.P.

1987-01-01

The methods of neutron activation analysis of high-purity zinc with preliminary separation of the zinc base using extraction by trialkylbenzylammonium rhodanide in carbon tetrachloride from 0.5-2.0 M nitric acid solutions is developed. Only rhenium is quantitatively extracted together with zinc. Gold, iridium and molybdenum are extracted to 50-60%, and selenium - to 20%. The Na, K, La, Cr, Sc, Co, Cs, Rb, Fe, Zr, Sn, Te, As, Cd, Hf, W, Sb, Sm impurities remain in the aqueous phase. The methods permits to determine the impurities above with detection limits from 1x10 -6 to 4x10 -11 g

Technology for sodium purity control

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ji Young; Kim, B. H.; Kim, T. J. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-10-01

When sodium is used as heat transfer fluid, the plugging in coolant flow, the corrosion of structure material and the transfer of radioactive material caused by the impurities in sodium are worth considerable. Accordingly, these impurities must be monitored and controlled continuously by sodium purification devices in the heat transfer system which sodium is used as coolant. Sodium purification loop was constructed for the purpose of accumulating the technology for purity control of the coolant, developing and verifying further efficient instruments for sodium purification. The plugging meter and the cold trap is used as the implement for measuring and controlling the oxygen and the hydrogen, the main impurities in sodium coolant. They are capable of excellent performance as the implements which could detect and monitor the impurities to the concentration limit required for nuclear reactor. Sodium purification loop could be used variably according to the experimental purpose. 18 refs., 34 figs., 8 tabs. (Author)

Assessment of the direct cyclotron production of (99m)Tc: An approach to crisis management of (99m)Tc shortage.

Science.gov (United States)

Rovais, Mohammad Reza Aboudzadeh; Aardaneh, Khosro; Aslani, Gholamreza; Rahiminejad, Ali; Yousefi, Kamran; Boulouri, Fatemeh

2016-06-01

Nowadays, the cyclotron production of technetium-99m ((99m)Tc) has been increased, due to the worldwide (99m)Tc generator shortage. In the present work, an improved strategy for the production of (99m)Tc, using the proton irradiation of the enriched (100)Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA(-1)h(-1). A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of (99m)Tc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the (99m)Tc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced (99m)Tc is suitable for preparation of USP-compliant. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous determination of dysprosium, holmium and erbium in high purity rare earth oxides by second order derivative spectrophotometry

International Nuclear Information System (INIS)

Anbu, M.; Prasada Rao, T.; Iyer, C. S. P.; Damodaran, A. D.

1996-01-01

High purity individual rare earth oxides are increasingly used as major components in lasers (Y 2 O 3 ), phosphors (YVO 3 , Eu 2 O 3 ), magnetic bubble memory films (Gd 2 O 3 ) and refractive-index lenses and fibre optics (La 2 O 3 ). The determination of individual lanthanides in high purity rare earth oxides is a more important and difficult task. This paper reports the utilization of higher order derivative spectrophotometry for the simultaneous determination of dysprosium, holmium and erbium in high purity rare earth oxides. The developed procedure is simple, reliable and allows the determination of 0.001 to 0.2% of dysprosium, holmium and erbium in several rare earth. (author). 9 refs, 2 figs, 2 tabs

Measurement scheme for purity based on two two-body gates

Science.gov (United States)

Nakazato, H.; Tanaka, T.; Yuasa, K.; Florio, G.; Pascazio, S.

2012-04-01

A scheme for measuring the purity of a quantum system with a finite number of levels is presented. The method makes use of two swap gates and hinges only on measurements performed on a reference system, prepared in a certain pure state and coupled with the target system. Neither tomographic methods, with the complete reconstruction of the state, nor interferometric setups are needed.

Void swelling in fast reactor irradiated high purity binary iron-chromium alloys

International Nuclear Information System (INIS)

Little, E.A.; Stow, D.A.

The void swelling characteristics of a series of high purity binary iron-chromium alloys containing 0 - 615 0 C. The void swelling behaviour can be qualitatively rationalized in terms of point defect trapping and precipitation processes involving chromium atoms

Preparation of high-purity cerium nitrate; Preparacao de nitrato de cerio de alta pureza

Energy Technology Data Exchange (ETDEWEB)

Avila, Daniela Moraes; Silva Queiroz, Carlos Alberto da; Santos Mucillo, Eliana Navarro dos [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

1995-12-31

The preparation of high-purity cerium nitrate has been carried out Cerium oxide has been prepared by fractioned precipitation and ionic exchange techniques, using a concentrate with approximately 85% of cerium oxide from NUCLEMON as raw material. Five sequential ion-exchange columns with a retention capacity of 170 g each have been used. The ethylenediamine-tetraacetic acid (EDTA) was used as eluent. The cerium content has been determined by gravimetry and iodometry techniques. The resulting cerium oxide has a purity > 99%. This material was transformed in cerium nitrate to be used as precursor for the preparation of Zirconia-ceria ceramics by the coprecipitation technique. (author) 2 tabs.

Isotopic Abundance and Chemical Purity Analysis of Stable Isotope Deuterium Labeled Sudan I

Directory of Open Access Journals (Sweden)

CAI Yin-ping;LEI Wen;ZHENG Bo;DU Xiao-ning

2014-02-01

Full Text Available It is important that to analysis of the isotopic abundance and chemical purity of Sudan I-D5, which is the internal standard of isotope dilution mass spectrometry. The isotopic abundance of Sudan I-D5 is detected by “mass cluster” classification method and LC-MS. The repeatability and reproducibility experiments were carried out by using different mass spectrometers and different operators. The RSD was less than 0.1%, so the repeatability and reproducibility were satisfactory. The accuracy and precision of the isotopic abundance analysis method was good with the results of F test and t test. The high performance liquid chromatography (HPLC had been used for detecting the chemical purity of Sudan I-D5 as external standard method.

Target development for 67Cu, 82Sr radionuclide production at the RIC-80 facility

Science.gov (United States)

Panteleev, V. N.; Barzakh, A. E.; Batist, L. Kh.; Fedorov, D. V.; Ivanov, V. S.; Krotov, S. A.; Molkanov, P. L.; Moroz, F. V.; Orlov, S. Yu.; Volkov, Yu. M.

2018-01-01

A high-current cyclotron C-80 capable of producing 40-80 MeV proton beams with a current of up to 200 μA has been constructed and commissioned at PNPI (Petersburg Nuclear Physics Institute). One of the main goals of cyclotron C-80 is the production of a wide spectrum of medical radionuclides for diagnostics and therapy. To date, the project development of a radioisotope facility RIC-80 (radioisotopes at cyclotron C-80) has been completed. The feature of the project is the use of a mass-separator combined with the ion-target device for obtaining ion beams of radioisotopes with a high purity of separation that is especially important for medical applications. The first results of a new high-temperature method for extracting 82Sr and 67Cu radioisotopes from irradiated targets have been presented.

Comparison of the production of medical radioisotopes on reactor and cyclotron

International Nuclear Information System (INIS)

Vucina, J.; Vuksanovic, Lj.; Dobrijevic, R.; Karanfilov, E.

1997-01-01

The production of radioisotopes for nuclear-medical applications can be performed either on nuclear reactor or on cyclotron. According to the nuclear reactions applied the radioisotopes of different physical characteristics can be produced. In the paper a comparison of the radioisotopes production given. Compared are the main steps in the production: choice of the nuclear reaction, targetry, irradiation and radiochemical separations performed on the irradiated target to isolate the desired radioisotope. The main characteristics of the produced radioisotopes are given and discussed. (author)

Production and characterization of anti-human IgG F(ab')2 antibody fragment.

Science.gov (United States)

Valedkarimi, Zahra; Nasiri, Hadi; Aghebati-Maleki, Leili; Abdolalizadeh, Jalal; Esparvarinha, Mojghan; Majidi, Jafar

2018-04-10

In present study an optimized protocol for the separation of antibodies into antigen-binding fragments F(ab')2 using pepsin digestion was investigated. The production of these fragments is a consequential step in the development of medical research, treatment and diagnosis. For production of polyclonal antibody rabbit received antigen in four steps. The rabbit serum at 1/128000 dilution showed high absorbance in reaction with human IgG at the designed ELISA method. Rabbit IgG was purified by Ion-Exchange Chromatography (IEC) method. Purity was assessed by SDS-PAGE method. In non-reduced condition only one band was seen in about 150 kDa MW position and in reduced form, two bands were seen in 50 and 25 kDa MW positions. Rabbit IgG was digested by pepsin enzyme. The antibody fragments solution was applied to Gel filtration column to isolate the F(ab')2. Non-reduced SDS-PAGE for determining the purity of F(ab')2 fragment resulted in one band in 100 kDa corresponds to F(ab')2 fragment and a band in 150 kDa MW position corresponds to undigested IgG antibodies. The activities of FITC conjugated F(ab')2 fragment and commercial ones were compared using flowcytometry method. The activity results implied that the FITC conjugated- anti human F(ab')2 fragment worked as efficiently as the commercial one.

Pre-sterilization contamination of disposable medical products and the choice of minimum sterilization dose

International Nuclear Information System (INIS)

Horakova, V.; Buriankova, E.

1975-01-01

The bacterial contamination was assessed on randomly taken samples of blood-transfusion devices, donor sets, intra-uterine contraceptive devices and inserters, surgical gloves and dressing material prior to sterilization. The quantitative and qualitative efficiency of six nutrient media was compared. The best results were obtained with the enriched ''Universal'' medium. It was confirmed that the contamination of plastic products was low compared with dressing material. Most frequently, Gram-positive aerobic spore-forming rods and Gram-positive cocci were found on non-sterile medical disposable products. A method was tested to obtain a general informative picture of the resistance of bacteria on products. The methods used for choosing the dose for radiation sterilization of medical products are discussed. (author)

Application of Digital Image Analysis to Determine Pancreatic Islet Mass and Purity in Clinical Islet Isolation and Transplantation

Science.gov (United States)

Wang, Ling-jia; Kissler, Hermann J; Wang, Xiaojun; Cochet, Olivia; Krzystyniak, Adam; Misawa, Ryosuke; Golab, Karolina; Tibudan, Martin; Grzanka, Jakub; Savari, Omid; Grose, Randall; Kaufman, Dixon B; Millis, Michael; Witkowski, Piotr

2015-01-01

Pancreatic islet mass, represented by islet equivalent (IEQ), is the most important parameter in decision making for clinical islet transplantation. To obtain IEQ, the sample of islets is routinely counted manually under a microscope and discarded thereafter. Islet purity, another parameter in islet processing, is routinely acquired by estimation only. In this study, we validated our digital image analysis (DIA) system developed using the software of Image Pro Plus for islet mass and purity assessment. Application of the DIA allows to better comply with current good manufacturing practice (cGMP) standards. Human islet samples were captured as calibrated digital images for the permanent record. Five trained technicians participated in determination of IEQ and purity by manual counting method and DIA. IEQ count showed statistically significant correlations between the manual method and DIA in all sample comparisons (r >0.819 and p islet particle number (IPN) and the IEQ/IPN ratio did not differ statistically between manual counting method and DIA. In conclusion, the DIA used in this study is a reliable technique in determination of IEQ and purity. Islet sample preserved as a digital image and results produced by DIA can be permanently stored for verification, technical training and islet information exchange between different islet centers. Therefore, DIA complies better with cGMP requirements than the manual counting method. We propose DIA as a quality control tool to supplement the established standard manual method for islets counting and purity estimation. PMID:24806436

Strategies for cost-effective and enhanced production of bacterial cellulose.

Science.gov (United States)

Islam, Mazhar Ul; Ullah, Muhammad Wajid; Khan, Shaukat; Shah, Nasrullah; Park, Joong Kon

2017-09-01

Bacterial cellulose (BC) has received substantial attention because of its high purity, mechanical strength, crystallinity, liquid-absorbing capabilities, biocompatibility, and biodegradability etc. These properties allow BC to be used in various fields, especially in industries producing medical, electronic, and food products etc. A major discrepancy associated with BC is its high production cost, usually much higher than the plant cellulose. To address this limitations, researchers have developed several strategies for enhanced production of BC including the designing of advanced reactors and utilization of various carbon sources. Another promising approach is the production of BC from waste materials such as food, industrial, agricultural, and brewery wastes etc. which not only reduces the overall BC production cost but is also environment-friendly. Besides, exploration of novel and efficient BC producing microbial strains provides impressive boost to the BC production processes. To this end, development of genetically engineered microbial strains has proven useful for enhanced BC production. In this review, we have summarized major efforts to enhance BC production in order to make it a cost-effective biopolymer. This review can be of interest to researchers investigating strategies for enhanced BC production, as well as companies exploring pilot projects to scale up BC production for industrial applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Demands made on high-purity copper for special purposes

International Nuclear Information System (INIS)

Roettges, D.

1977-01-01

The properties (electrical resistivity, residual impurities) of high-purity copper produced on a technical scale are reported as well as its practical applications. The paper discusses a high-oxygen copper (SV) with low residual resistivity at low temperatures and an oxygen-free (hydrogen-stable) copper (BE electronic) with low gas content. The SV quality has been specially developed for use as stabilizer in superconductors while the BE quality is used in high and ultrahigh vacuum. (GSC) [de

Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production

Science.gov (United States)

Jujasz, Albert J.; Burkhart, James A.; Greenberg, Ralph

1988-01-01

A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

The public production and sharing of medical information. An Australian perspective

Directory of Open Access Journals (Sweden)

Henry C.H. Ko

2010-03-01

Full Text Available There is a wealth of medical information now available to the public through various sources that are not necessarily controlled by medical or healthcare professionals. In Australia there has been a strong movement in the health consumer arena of consumer-led sharing and production of medical information and in healthcare decision-making. This has led to empowerment of the public as well as increased knowledge-sharing. There are some successful initiatives and strategies on consumer- and public-led sharing of medical information, including the formation of specialised consumer groups, independent medical information organisations, consumer peer tutoring, and email lists and consumer networking events. With well-organised public initiatives and networks, there tends to be fairly balanced information being shared. However, there needs to be caution about the use of publicly available scientific information to further the agenda of special-interest groups and lobbying groups to advance often biased and unproven opinions or for scaremongering. With the adoption of more accountability of medical research, and the increased public scrutiny of private and public research, the validity and quality of medical information reaching the public is achieving higher standards.

Grain Size and Phase Purity Characterization of U3Si2 Pellet Fuel

Energy Technology Data Exchange (ETDEWEB)

Hoggan, Rita E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tolman, Kevin R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cappia, Fabiola [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wagner, Adrian R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2018-05-01

Characterization of U3Si2 fresh fuel pellets is important for quality assurance and validation of the finished product. Grain size measurement methods, phase identification methods using scanning electron microscopes equipped with energy dispersive spectroscopy and x-ray diffraction, and phase quantification methods via image analysis have been developed and implemented on U3Si2 pellet samples. A wide variety of samples have been characterized including representative pellets from an initial irradiation experiment, and samples produced using optimized methods to enhance phase purity from an extended fabrication effort. The average grain size for initial pellets was between 16 and 18 µm. The typical average grain size for pellets from the extended fabrication was between 20 and 30 µm with some samples exhibiting irregular grain growth. Pellets from the latter half of extended fabrication had a bimodal grain size distribution consisting of coarsened grains (>80 µm) surrounded by the typical (20-30 µm) grain structure around the surface. Phases identified in initial uranium silicide pellets included: U3Si2 as the main phase composing about 80 vol. %, Si rich phases (USi and U5Si4) composing about 13 vol. %, and UO2 composing about 5 vol. %. Initial batches from the extended U3Si2 pellet fabrication had similar phases and phase quantities. The latter half of the extended fabrication pellet batches did not contain Si rich phases, and had between 1-5% UO2: achieving U3Si2 phase purity between 95 vol. % and 98 vol. % U3Si2. The amount of UO2 in sintered U3Si2 pellets is correlated to the length of time between U3Si2 powder fabrication and pellet formation. These measurements provide information necessary to optimize fabrication efforts and a baseline for future work on this fuel compound.

Cross Purposes: Love and Purity at a Puerto Rican Protestant High School

Science.gov (United States)

Seale-Collazo, James

2013-01-01

A "native" Christian ethnographer finds religious education at this church-sponsored school to pursue two distinct, and occasionally conflicting, curricula: "love" and "purity." The curriculum of love draws on what Turner called liminality and communitas in an effort to promote spiritual "encounters with…

Law and Behavioral Sciences: Why We Need Less Purity Rather than More

NARCIS (Netherlands)

P. Mascini (Peter)

2016-01-01

markdownabstractIn his inaugural lecture, Peter Mascini takes issue with the goal of scientific purity in the behavioral study of the law, conceived as the deliberate choice to postulate a limited number of universally applicable behavioral principles. The guiding principle of behavioral sociology

Production process for ursolic acid%乌索酸的生产工艺

Institute of Scientific and Technical Information of China (English)

李开泉; 陈武; 李翔一

2006-01-01

Production of ursolic acid, the anti-hepatitis effective composition from natural plant,Sambucus chinensis Lindl.was carried out and the scale-up preparation technology was studied.Extraction of the herb Sambucus chinensis Lindl.was extracted in reflux with 7 volume times of refluxing ethanol at 80℃ for 1 h for two times.The extract was purified with a selt-made specific impurity remover "YCXY-1" to yield ursolic acid of high purity.A new "Extraction/Gelation" technology for the production of ursolic acid was developed. The specific impurity remover "YCXY-1" showed high effectiveness in purification. The purity of the mass-produced ursolic acid was up to 99.8%. The chemical structure of the product was confirmed by the physicochemical constants and spectroscopic identification. The production of high-purity ursolic acid was optimized with natural plant as raw material and with only ethanol as extracting solvent. The difficulties such as isolation and impurity removal were addressed effectively. The novel technology is reasonable, convenient, practical, low-cost, high-yield, suitable for mass production.

Production of medical radioactive isotopes using KIPT electron driven subcritical facility

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Yousry

2008-01-01

Kharkov Institute of Physics and Technology (KIPT) of Ukraine in collaboration with Argonne National Laboratory (ANL) has a plan to construct an electron accelerator driven subcritical assembly. One of the facility objectives is the production of medical radioactive isotopes. This paper presents the ANL collaborative work performed for characterizing the facility performance for producing medical radioactive isotopes. First, a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Then, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes have been considered and all transmutation channels are used including (n, γ), (n, 2n), (n, p), and (γ, n). In the second part, the parent isotopes with high reaction rate were explicitly modeled in the calculations. Four irradiation locations were considered in the analyses to study the medical isotope production rate. The results show the self-shielding effect not only reduces the specific activity but it also changes the irradiation location that maximizes the specific activity. The axial and radial distributions of the parent capture rates have been examined to define the irradiation sample size of each parent isotope

Production of medical radioactive isotopes using KIPT electron driven subcritical facility

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: alby@anl.gov; Gohar, Yousry [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2008-05-15

Kharkov Institute of Physics and Technology (KIPT) of Ukraine in collaboration with Argonne National Laboratory (ANL) has a plan to construct an electron accelerator driven subcritical assembly. One of the facility objectives is the production of medical radioactive isotopes. This paper presents the ANL collaborative work performed for characterizing the facility performance for producing medical radioactive isotopes. First, a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Then, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes have been considered and all transmutation channels are used including (n, {gamma}), (n, 2n), (n, p), and ({gamma}, n). In the second part, the parent isotopes with high reaction rate were explicitly modeled in the calculations. Four irradiation locations were considered in the analyses to study the medical isotope production rate. The results show the self-shielding effect not only reduces the specific activity but it also changes the irradiation location that maximizes the specific activity. The axial and radial distributions of the parent capture rates have been examined to define the irradiation sample size of each parent isotope.

Production of medical radioactive isotopes using KIPT electron driven subcritical facility.

Science.gov (United States)

Talamo, Alberto; Gohar, Yousry

2008-05-01

Kharkov Institute of Physics and Technology (KIPT) of Ukraine in collaboration with Argonne National Laboratory (ANL) has a plan to construct an electron accelerator driven subcritical assembly. One of the facility objectives is the production of medical radioactive isotopes. This paper presents the ANL collaborative work performed for characterizing the facility performance for producing medical radioactive isotopes. First, a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Then, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes have been considered and all transmutation channels are used including (n, gamma), (n, 2n), (n, p), and (gamma, n). In the second part, the parent isotopes with high reaction rate were explicitly modeled in the calculations. Four irradiation locations were considered in the analyses to study the medical isotope production rate. The results show the self-shielding effect not only reduces the specific activity but it also changes the irradiation location that maximizes the specific activity. The axial and radial distributions of the parent capture rates have been examined to define the irradiation sample size of each parent isotope.

Radioactive Emissions from Fission-Based Medical Isotope Production and Their Effect on Global Nuclear Explosion Detection

International Nuclear Information System (INIS)

Bowyer, T.; Saey, P.

2015-01-01

The use of medical isotopes, such as Tc-99m, is widespread with over 30 million procedures being performed every year, but the fission-based production of isotopes used for medical procedures causes emissions into the environment. This paper will show that gaseous radioactive isotopes of xenon, such as Xe-133, are released in high quantities, because they have a high fission cross section and they are difficult to scrub from the processes used to produce the medical isotopes due to their largely unreactive nature. Unfortunately, the reasons that large amounts of radioactive xenon isotopes are emitted from isotope production are the same as those that make these isotopes the most useful isotopes for the detection of underground nuclear explosions. Relatively recently, the nuclear explosion monitoring community has established a provisional monitoring network for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) that includes radioactive xenon monitoring as a major component. This community has discovered that emissions from medical isotope production present a more serious problem to nuclear explosion monitoring than thought when the network was first conceived. To address the growing problem, a group of scientists in both the monitoring and the isotope production communities have come together to attempt to find scientific and pragmatic ways to address the emissions problems, recognizing that medical isotope production should not be adversely affected, while monitoring for nuclear explosions should remain effective as isotope production grows, changes, and spreads globally. (author)

Aluminum anode for aluminum-air battery - Part I: Influence of aluminum purity

Science.gov (United States)

Cho, Young-Joo; Park, In-Jun; Lee, Hyeok-Jae; Kim, Jung-Gu

2015-03-01

2N5 commercial grade aluminum (99.5% purity) leads to the lower aluminum-air battery performances than 4N high pure grade aluminum (99.99% purity) due to impurities itself and formed impurity complex layer which contained Fe, Si, Cu and others. The impurity complex layer of 2N5 grade Al declines the battery voltage on standby status. It also depletes discharge current and battery efficiency at 1.0 V which is general operating voltage of aluminum-air battery. However, the impurity complex layer of 2N5 grade Al is dissolved with decreasing discharge voltage to 0.8 V. This phenomenon leads to improvement of discharge current density and battery efficiency by reducing self-corrosion reaction. This study demonstrates the possibility of use of 2N5 grade Al which is cheaper than 4N grade Al as the anode for aluminum-air battery.

Dissolution of high-purity lead and subsequent crystal growth during the preparation of corrosion coupons

Energy Technology Data Exchange (ETDEWEB)

McGarvey, G.B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); McDougall, T.E.; Owen, D.G. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

1997-07-01

High-purity lead discs were prepared using several combinations of polishing, rinsing and ultrasonic treatment. Physical degradation of the lead surface and the premature generation and deposition of oxides on the surface were observed for certain combinations of preparation steps. Ultrasonic treatment of the discs was found to be particularly detrimental as it induced significant crystal growth and, in several instances, deterioration of the polished surface. Simple air drying of freshly rinsed discs also led to oxide formation on the surface after as short a time as 1 min. An effective method for preparing discs from high-purity lead is described. (author)

Dissolution of high-purity lead and subsequent crystal growth during the preparation of corrosion coupons

International Nuclear Information System (INIS)

McGarvey, G.B.; McDougall, T.E.; Owen, D.G.

1997-01-01

High-purity lead discs were prepared using several combinations of polishing, rinsing and ultrasonic treatment. Physical degradation of the lead surface and the premature generation and deposition of oxides on the surface were observed for certain combinations of preparation steps. Ultrasonic treatment of the discs was found to be particularly detrimental as it induced significant crystal growth and, in several instances, deterioration of the polished surface. Simple air drying of freshly rinsed discs also led to oxide formation on the surface after as short a time as 1 min. An effective method for preparing discs from high-purity lead is described. (author)

Development and implementation of an herbal and natural product elective in undergraduate medical education.

Science.gov (United States)

Karpa, Kelly

2012-05-22

Medical students have consistently expressed interest in learning about alternative healing modalities, especially herbal and natural products. To fill this void in medical education at our institution, a novel elective was developed and implemented for fourth year medical students. This herbal/natural product course uses guest lecturers, classroom presentations, and active learning mechanisms that include experiential rotations, case-based learning, and team-based learning to increase student knowledge of herbal/natural product safety and efficacy. Knowledge outcomes were evaluated via administration of a pre- and post-course test (paired student t-test). End-of-course evaluations (Likert-type questions and narrative responses) were used to assess student opinion of knowledge and skills imparted by the elective and overall course content (mean, standard deviation). Over three academic years, 23 students have enrolled in this elective. More than 60% of participants have been female and nearly half of the students (43%) have pursued residencies in primary care. Completion of the course significantly increased student knowledge of common herbal/natural product mechanisms, uses, adverse effects, and drug-interactions as determined by a pre- and post-course knowledge assessment (45%±10% versus 78%±6%; pvariety of activities to which they were exposed and the open classroom discussions that resulted. While students tended to view some alternative medical systems with skepticism, they still believed it was valuable to learn what these modalities encompass. Development and implementation of a herbal/natural product elective that engages undergraduate medical students through active learning mechanisms and critical analysis of the literature has proven effective in increasing knowledge outcomes and is deemed to be a valuable curricular addition by student participants. In the future, it will be of interest to explore mechanisms for expanding the course to reach a larger

Medical Isotopes Production Project: Molybdenum-99 and related isotopes: Environmental Impact Statement, Volume I

International Nuclear Information System (INIS)

1996-04-01

This Environmental Impact Statement (EIS) provides environmental and technical information concerning the U.S. Department of Energy's (DOE) proposal to establish a domestic source to produce molybdenum-99 (Mo-99) and related medical isotopes (iodine-131, xenon-133 and iodine-125). Mo-99, a radioactive isotope of the element molybdenum, decays to form metastable technetium-99 (Tc-99m), a radioactive isotope used thousands of times daily in medical diagnostic procedures in the U.S. Currently, all Mo-99 used in the U.S. is obtained from a single Canadian source. DOE is pursuing the Medical Isotopes Production Project in order to ensure that a reliable supply of Mo-99 is available to the U.S. medical community. Under DOE's preferred alternative, the Chemistry and Metallurgy Research Facility at the Los Alamos National Laboratory (LANL) and the Annular Core Research Reactor and Hot Cell Facility at Sandia National Laboratories/New Mexico (SNL/NM) would be used for production of the medical isotopes. In addition to the preferred alternative, three other reasonable alternatives and a no action alternative are analyzed in detail. The sites for the three reasonable alternatives are LANL, Oak Ridge National Laboratory (ORNL), and Idaho National Engineering Laboratory (INEL). The analyses in this EIS indicate no significant difference in the potential environmental impacts among the alternatives. Each of the alternatives would use essentially the same technology for the production of the medical isotopes. Minor differences in environmental impacts among alternatives relate to the extent of activity necessary to modify and restart (as necessary) existing reactors and hot cell facilities at each of the sites, the quantities, of low-level radioactive waste generated, how such waste would be managed, and the length of time needed for initial and full production capacity

Trace elements in high purity materials for advanced technology: contribution of neutron activation analysis and radioanalytical technique

International Nuclear Information System (INIS)

Gallorini, M.; Pietra, R.; Sabbioni, E.

1991-01-01

Neutron activation analysis and radioanalytical techniques have been employed to investigate problems related to trace elements and high purity technology materials. Applications of these techniques are overviewed: semiconductor technology as in the case of As and In ion implantation in high purity silicon; problems related to trace elements impurities in thermometric measurements; coating materials to prevent trace elements contamination in biological sampling and metals release from human prostheses. (author) 8 refs.; 2 figs.; 8 tabs

Preparation of carrier-free radioactive thallium for medical use

International Nuclear Information System (INIS)

Comar, D.; Crouzel, C.

1975-01-01

Radioactive thallium for medical use have been prepared by proton or deuteron bombardment of HgO or metallic Hg. The carrier free thallium is separated from mercury by ether extraction of the chloride. The yield of production for the isotopes 198m to 202 is given for different energies of protons and deuterons. The irradiated substances consisted of red mercury oxide containing less than 1 ppm iron, and high-purity (99.999%) metallic mercury. The red mercury oxide targets were irradiated with 15 MeV deuterons (M.R.C. cyclotron, Hammersmith Hospital-London and Saclay Van de Graff tandem) or 50 and 14 MeV protons (Grenoble Nuclear Physics Institute cyclotron and S.H.F.J. compact cyclotrons). The metallic mercury target was irradiated with 14, 16 and 20 MeV protons (S.H.F.J. compact cyclotron and Saclay variable-energy cyclotron). The particle current never exceeded 10 μA for irradiation times between 15 minutes and a few hours. (F.Gy.)

Off-label use of medical products in radiation therapy: Summary of the Report of AAPM Task Group No. 121

International Nuclear Information System (INIS)

Thomadsen, Bruce R.; Thompson, Heaton H. II; Jani, Shirish K.

2010-01-01

Medical products (devices, drugs, or biologics) contain information in their labeling regarding the manner in which the manufacturer has determined that the products can be used in a safe and effective manner. The Food and Drug Administration (FDA) approves medical products for use for these specific indications which are part of the medical product's labeling. When medical products are used in a manner not specified in the labeling, it is commonly referred to as off-label use. The practice of medicine allows for this off-label use to treat individual patients, but the ethical and legal implications for such unapproved use can be confusing. Although the responsibility and, ultimately, the liability for off-label use often rests with the prescribing physician, medical physicists and others are also responsible for the safe and proper use of the medical products. When these products are used for purposes other than which they were approved, it is important for medical physicists to understand their responsibilities. In the United States, medical products can only be marketed if officially cleared, approved, or licensed by the FDA; they can be used if they are not subject to or specifically exempt from FDA regulations, or if they are being used in research with the appropriate regulatory safeguards. Medical devices are either cleared or approved by FDA's Center for Devices and Radiological Health. Drugs are approved by FDA's Center for Drug Evaluation and Research, and biological products such as vaccines or blood are licensed under a biologics license agreement by FDA's Center for Biologics Evaluation and Research. For the purpose of this report, the process by which the FDA eventually clears, approves, or licenses such products for marketing in the United States will be referred to as approval. This report summarizes the various ways medical products, primarily medical devices, can legally be brought to market in the United States, and includes a discussion of the

Off-label use of medical products in radiation therapy: Summary of the Report of AAPM Task Group No. 121

Energy Technology Data Exchange (ETDEWEB)

Thomadsen, Bruce R.; Thompson, Heaton H. II; Jani, Shirish K. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States); Hagerstown, Maryland 21740 (United States); and others

2010-05-15

Medical products (devices, drugs, or biologics) contain information in their labeling regarding the manner in which the manufacturer has determined that the products can be used in a safe and effective manner. The Food and Drug Administration (FDA) approves medical products for use for these specific indications which are part of the medical product's labeling. When medical products are used in a manner not specified in the labeling, it is commonly referred to as off-label use. The practice of medicine allows for this off-label use to treat individual patients, but the ethical and legal implications for such unapproved use can be confusing. Although the responsibility and, ultimately, the liability for off-label use often rests with the prescribing physician, medical physicists and others are also responsible for the safe and proper use of the medical products. When these products are used for purposes other than which they were approved, it is important for medical physicists to understand their responsibilities. In the United States, medical products can only be marketed if officially cleared, approved, or licensed by the FDA; they can be used if they are not subject to or specifically exempt from FDA regulations, or if they are being used in research with the appropriate regulatory safeguards. Medical devices are either cleared or approved by FDA's Center for Devices and Radiological Health. Drugs are approved by FDA's Center for Drug Evaluation and Research, and biological products such as vaccines or blood are licensed under a biologics license agreement by FDA's Center for Biologics Evaluation and Research. For the purpose of this report, the process by which the FDA eventually clears, approves, or licenses such products for marketing in the United States will be referred to as approval. This report summarizes the various ways medical products, primarily medical devices, can legally be brought to market in the United States, and includes a

Towards the production of EPA: a developing country perspective

CSIR Research Space (South Africa)

Maharajh, Dheepak M

2015-03-01

Full Text Available are focussed towards increased production of high purity EPA. This provides a window of opportunity for a supply of competing products that are rich in algal EPA. Recently the CSIR developed a technology for the production of EPA by an indigenous algal isolate...

Native oxidation of ultra high purity Cu bulk and thin films

International Nuclear Information System (INIS)

Iijima, J.; Lim, J.-W.; Hong, S.-H.; Suzuki, S.; Mimura, K.; Isshiki, M.

2006-01-01

The effect of microstructure and purity on the native oxidation of Cu was studied by using angle-resolved X-ray photoelectron spectroscopy (AR-XPS) and spectroscopic ellipsometry (SE). A high quality copper film prepared by ion beam deposition under a substrate bias voltage of -50 V (IBD Cu film at V s = -50 V) showed an oxidation resistance as high as an ultra high purity copper (UHP Cu) bulk, whereas a Cu film deposited without substrate bias voltage (IBD Cu film at V s = 0 V) showed lower oxidation resistance. The growth of Cu 2 O layer on the UHP Cu bulk and both types of the films obeyed in principle a logarithmic rate law. However, the growth of oxide layer on the IBD Cu films at V s = 0 and -50 V deviated upward from the logarithmic rate law after the exposure time of 320 and 800 h, respectively. The deviation from the logarithmic law is due to the formation of CuO on the Cu 2 O layer after a critical time

Production of PET radiopharmaceutical 18F-FDG using synthesizer automatic module

International Nuclear Information System (INIS)

Purwoko; Chairuman; Adang Hardi Gunawan; Yayan Tahyan; Eny Lestari; Sri Aguswarini Lestiyowati; Karyadi; Sri Bagiawati

2010-01-01

Radiopharmaceutical 2-( 18 F)Fluoro-2-Deoxy-D-Glucose or 18 F(FDG) is an important PET (Positron Emission Tomography) radiopharmaceutical for tumour imaging. In the PET technique glucose metabolism in tumour tissues can be determined quantitatively and used for diagnosis staging and monitoring of treatment tumour or cancer disease in medical oncology. The production of 2-( 18 F)Fluoro-2-Deoxy-D-Glucose 18 F-FDG using compact automated system module TRACERlab MX has been carried out. The modular setup of the apparatus permits reliable for routine synthesis of radiopharmaceuticals 18 F-FDG based on kriptofix mediated nucleophilic fluorination to mannose triflate precursor. Radiochemical yield of 18 F-FDG was 53.895 % (decay time uncorrected) in 40 minutes. The product showed that the colorless and clear solution at pH:6, sterile and pirogen free, kriptofix impurities was low and radiochemical purity was 99.595%. (author)

Research Productivity of ]unior Academic Staff at a Tertiary Medical ...

African Journals Online (AJOL)

Research Productivity of ]unior Academic Staff at a Tertiary Medical College in South West, Nigeria. OA Lesi, OO Orenuga, A Roberts, OO Abudu. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.

Medical merchants: conflict of interest, office product sales and notifiable conduct.

Science.gov (United States)

Parker, Malcolm H; Wardle, Jon L; Weir, Michael; Stewart, Cameron L

2011-01-03

Professional ethical codes identify the issue of conflict of interest, which can distort doctors' objective judgements concerning the best interests of patients. Legal fiduciary duties may be owed by doctors to patients in situations of potential conflict of interest. Prescribing and dispensing functions have been largely legally separated to prevent conflicts of interest arising. The advent of integrative medicine has been accompanied by an apparent growth of in-house selling of therapeutic products. Medical merchandising constitutes a prima-facie conflict of interest and may amount to notifiable conduct under the Health Practitioner Regulation National Law provisions. We believe that doctors who sell therapeutic products should adhere to strict conditions to avoid significantly departing from accepted professional standards. Doctors who have a reasonable belief that a colleague is failing to comply with these conditions could consider notifying the Medical Board of Australia.

Investigation of science production in Iran’s type I universities of medical sciences, a 6-year assessment

Directory of Open Access Journals (Sweden)

M Yadollahi

2014-07-01

Full Text Available Introduction: Science production is one of the main dimensions of sustainable development in any country. Thus, universities as the major centers for science production play a key role in development. The present study aimed to assess the trend of science production in Iran’s type I universities of medical sciences from 2007 to 2012. Method: In this study, the universities’ scores of empowering, governance and leadership, science production, student researches, and number of published articles were computed based on the evaluations of universities of medical sciences by the Ministry of Health, Treatment, and Medical Education from 2007 to 2012. Then, the data were analyzed using descriptive statistics and the figures were drawn by Excel software. Results: This study assessed science production in Iran’s type I universities of medical sciences and analyzed each university’s proportion in publication of articles. According to the results, most of the published articles were affiliated to Tehran University of Medical Sciences. However, considering the role of number of faculty members, different results were obtained. With respect to the evaluation raw scores, Isfahan University of Medical Sciences showed a considerable reduction of scores in 2012, while other universities had a constant or ascending trend. Besides, indexed articles followed an ascending trend in all the universities and most of the articles had been published in index 1. Conclusion: Similar to other studies, the findings of this study revealed an increase in science productions in Iran through the recent years. Yet, the highest scores of the studied indexes, except for student researches, were related to Tehran University of Medical Sciences. This great difference between this university and other universities might be due to accumulation of specific potentials and forces in this region. Overall, science productions followed an ascending trend in all type I universities of

Choice of the irradiation dose for the sterilization of medical products

International Nuclear Information System (INIS)

Bochkarev, V.V.; Pavlov, E.P.; Sedov, V.V.; Khrushchev, V.G.; Tushov, Eh.G.; Konyaev, G.A.

1975-01-01

The principles for selecting the appropriate dose for the radiation sterilization of medical products are set forth, taking into account the initial contamination of the product, the radiation senstivity of contaminants and the required level of reliability of sterilization. The initial contamination level of certain preparations (glucose and radiopharmaceuticals) is established and the radiation sensitivity of the isolated contaminants is determined in terms of Dio indices. Of the microorganisms isolated the most common were staphylococci, streptococci, Gram-negative bacteria, Aspergilli, Penicillia and yeast fungi. Spore-forming types of microorganisms were isolated with a frequency of the order of 10 -2 . The radiation sensitivity in terms of D 10 was established for more than 3000 strains of microorganisms. For 75-85% of the strains the D 10 indices gave 10-40 krad and for 0.2-1% more than 100 krad. The experimental data were subjected to computer analysis which confirmed the adequacy of the techniques used to determine radiosensitivity. The authors then calculated by computer the radiation sterilizing doses for different degrees of initial contamination of the products with reliability coefficients of 10 6 and 10 8 . For sterilizing radiopharmaceuticals and glucose solutions these doses are 0.8-1 Mrad. Verification experiments show that these doses give reliable sterilization of the medical products concerned. (author)

High-purity Cu nanocrystal synthesis by a dynamic decomposition method

OpenAIRE

Jian, Xian; Cao, Yu; Chen, Guozhang; Wang, Chao; Tang, Hui; Yin, Liangjun; Luan, Chunhong; Liang, Yinglin; Jiang, Jing; Wu, Sixin; Zeng, Qing; Wang, Fei; Zhang, Chengui

2014-01-01

Cu nanocrystals are applied extensively in several fields, particularly in the microelectron, sensor, and catalysis. The catalytic behavior of Cu nanocrystals depends mainly on the structure and particle size. In this work, formation of high-purity Cu nanocrystals is studied using a common chemical vapor deposition precursor of cupric tartrate. This process is investigated through a combined experimental and computational approach. The decomposition kinetics is researched via differential sca...

Safety evaluation in the development of medical devices and combination products

CERN Document Server

Gad, Shayne C

2008-01-01

Capturing the growth of the global medical device market in recent years, this practical new guide is essential for all who are responsible for ensuring safety in the use and manufacture of medical devices. It has been extensively updated to reflect significant advances, incorporating combination products and helpful case examples of current real-life problems in the field.The Third Edition explores these key current trends:global device marketscontinually advancing technologythe increasing harmonization of device safety regulation worldwideEach aspect of safety evaluation is considered in ter

BORDERLINE AND CLASSIFICATION IN THE COMMUNITY REGULATORY FRAMEWORK FOR MEDICAL DEVICES – BRIEF REVIEW ON SOME DENTISTRY PRODUCTS.

Directory of Open Access Journals (Sweden)

Maya Lyapina

2015-02-01

Full Text Available Defining a given product as a medical device and interpretation of the application of the classification rules fall within the competence of the competent authorities of the Member States where the product is on the market. Different interpretations of Community legislation occur, and, can put public health at risk and distort the internal market. Borderline cases are considered to be those cases where it is not clear from the outset whether a given product is a medical device, an in vitro diagnostic medical device, an active implantable medical device or not. Classification cases can be described as those cases where there exists a difficulty in the uniform application of the classification rules as laid down in the Medical Devices Directive (MDD, or where for a given device, depending on interpretation of the rules, different classifications can occur. The aim of the present work is to make a brief review on discussion on classification in the community regulatory framework for medical devices of some dentistry products.

FY 1999 results of the regional consortium R and D project/the regional consortium energy R and D. 1st year. Development of the energy-saving type production technology of high-purity/transparent silica glass; 1999 nendo kojundo tomei sekiei glass no sho energy gata seizo gijutsu no kaihatsu seika hokokusho. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of achieving the remarkable energy conservation, high accuracy and low cost in the production of high-purity/transparent silica glass, the developmental research was conducted on slip casting method. In the development of technology to synthesize silica powder by the sol-gel method, monodisperse - polydisperse high-purity colloidal silica was obtained. In the development of technology to make silica power ultra-highly pure, a process was found out in which silica particles can be obtained by applying moderate amounts of ammonium bicarbonate and aqueous ammonia to the solution of silicic acid for heating. In the slip cast forming, a high-density forming body with a mean particle size of 1.5{mu}m was obtained. In the trial manufacture of reflector model, a translucent silica glass sintered body was obtained by transcribing the gypsum type dimensional shape in high purity. Besides, experimental researches were conducted on the examination of gypsum type/resin type and evaluation of physical properties, heat deterioration characteristics of the actual multi-layer film and trial manufacture of the heat resistant film, analysis/evaluation of trace impurities inside silica glass, conditions for the manufacture of dense silica glass sheets, etc. (NEDO)

Capillary gel electrophoresis for the quantification and purity determination of recombinant proteins in inclusion bodies.

Science.gov (United States)

Espinosa-de la Garza, Carlos E; Perdomo-Abúndez, Francisco C; Campos-García, Víctor R; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

2013-09-01

In this work, a high-resolution CGE method for quantification and purity determination of recombinant proteins was developed, involving a single-component inclusion bodies (IBs) solubilization solution. Different recombinant proteins expressed as IBs were used to show method capabilities, using recombinant interferon-β 1b as the model protein for method validation. Method linearity was verified in the range from 0.05 to 0.40 mg/mL and a determination coefficient (r(2) ) of 0.99 was obtained. The LOQs and LODs were 0.018 and 0.006 mg/mL, respectively. RSD for protein content repeatability test was 2.29%. In addition, RSD for protein purity repeatability test was 4.24%. Method accuracy was higher than 90%. Specificity was confirmed, as the method was able to separate recombinant interferon-β 1b monomer from other aggregates and impurities. Sample content and purity was demonstrated to be stable for up to 48 h. Overall, this method is suitable for the analysis of recombinant proteins in IBs according to the attributes established on the International Conference for Harmonization guidelines. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dependence on liquid temperature and purity of light emission characteristics in single cavitation bubble luminescence

Energy Technology Data Exchange (ETDEWEB)

Barbaglia, Mario O; Bonetto, Fabian J [Consejo Nacional de Investigaciones Cientificas y Tecnicas and Instituto Balseiro, Centro Atomico Bariloche, Av. Bustillo 9500, CP8400, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Instituto Balseiro, and Comision Nacional de Energia Atomica, Laboratorio de Cavitacion y Biotecnologia, Centro Atomico Bariloche, Av. Bustillo 9500, CP8400, Rio Negro (Argentina)

2004-02-15

We produced single bubbles in water using a visible pulsed laser and studied the characteristics of the light emitted during the bubble collapse time as a function of the water temperature for different water purity values. The water temperature ranged from freezing point (0 deg. C) to near boiling. We measured the luminescence pulse for the mentioned temperature range at various purity values. We also obtained the average bubble lifetime and the average luminescence pulse emitted as a function of water temperature. The main conclusion was that the luminescence can be modified by the water quality and by the water temperature. Maximum luminescence was obtained near the water freezing point.

Dependence on liquid temperature and purity of light emission characteristics in single cavitation bubble luminescence

International Nuclear Information System (INIS)

Barbaglia, Mario O.; Bonetto, Fabian J.

2004-01-01

We produced single bubbles in water using a visible pulsed laser and studied the characteristics of the light emitted during the bubble collapse time as a function of the water temperature for different water purity values. The water temperature ranged from freezing point (0 deg. C) to near boiling. We measured the luminescence pulse for the mentioned temperature range at various purity values. We also obtained the average bubble lifetime and the average luminescence pulse emitted as a function of water temperature. The main conclusion was that the luminescence can be modified by the water quality and by the water temperature. Maximum luminescence was obtained near the water freezing point

Lost Purity. Social in Nineteenth and Twentieth-century Feminisms

OpenAIRE

Paola Persano

2016-01-01

‘Social Purity’ appears in a part of the French and Anglo-Saxon (Britain and the United States) nineteenth-twentieth century’s feminisms, as a mean for many claims: from the full recognition of sexual difference in Hubertine Auclert’s social and ‘differentialist’ republicanism in France to Josephine Butler’s refusal of any purity imposed from above in England, until the absolute turn of the idea of women’s moral superiority and the equal and opposite force to the final exit from ‘the social’ ...

Development of an installation for the production of high-purity hydrogen using the pressure-swing-adsorption process with coke-oven gas as feedstock

Energy Technology Data Exchange (ETDEWEB)

Nakamura, M; Sugishita, M

1986-04-01

This paper describes how Nippon Steel developed a process for producing high-purity hydrogen using the PSA method with coke-oven gas as a feedstock. The process comprises a gas-compression and gas-cooling stage, a pre-treatment stage, an adsorption stage, a de-oxygenation stage and various control and maintenance devices, etc. The triple-tower plant constructed is the equivalent of a four-tower conventional installation, with a maximum capacity of around 10,000 Nm/sup 3//h. 1 tab., 14 figs., 3 refs.

Preparation of High-purity Indium Oxalate Salt from Indium Scrap by Organic Acids

International Nuclear Information System (INIS)

Koo, Su-Jin; Ju, Chang-Sik

2013-01-01

Effect of organic acid on the preparation of indium-oxalate salt from indium scraps generated from ITO glass manufacturing process was studied. Effects of parameters, such as type and concentration of organic acids, pH of reactant, temperature, reaction time on indium-oxalate salt preparation were examined. The impurity removal efficiency was similar for both oxalic acid and citric acid, but citric acid did not make organic acid salt with indium. The optimum conditions were 1.5 M oxalic acid, pH 7, 80 .deg. C, and 6 hours. On the other hand, the recoveries increased with pH, but the purity decreased. The indium-oxalate salt purity prepared by two cycles was 99.995% (4N5). The indium-oxalate salt could be converted to indium oxide and indium metal by substitution reaction and calcination

Approaches to the accurate characterization of high purity metal fluorides and fluoride glasses

Science.gov (United States)

Beary, E. S.; Paulsen, P. J.; Rains, T. C.; Ewing, K. J.; Jaganathan, J.; Aggarwal, I.

1990-11-01

The analytical challenges posed by the measurement of trace contaminants in high purity metal fluorides require that innovative chemical preparation procedures be used to enhance existing instrumental techniques. The instrumental techniques used to analyze these difficult matrices must be sensitive enough to detect extremely low levels of trace impurities, and the background interferences derived from the matrix (metal fluoride or glass) must be minimized. A survey of analytical techniques that have the necessary characteristics to analyze these materials will be given. In addition, means of controlling the chemical blank will be presented. Mass and atomic spectrometric techniques will be discussed, specifically graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Analytical procedures using GFAAS and ICP-MS have been developed to determine sub ppb (part per billion) levels of contaminants in high purity fluoride materials.

Studies on the radiosterilization of medical products

International Nuclear Information System (INIS)

Lee, K.S.; Min, B.H.; Chun, K.J.; Kim, K.S.

1979-01-01

Most of the microorganisms isolated from the medical products were inactivated by the irradiation of 1.0-1.5 Mrad. However, some microorganisms were inactivated as the factor of 10 8 cells by the irradiation of 2.0-2.3 Mrad. Micrococcus roseus was a radioresistant strain, and on the view point of 10 8 cell number the dose for inactivating the Micrococcus roseus in a liquid and lyophilized condition was 2.3 and 3.5 Mrad, respectively. It has been found that the radiosensitivity of microorganism was influenced differently according to the suspended solution, oxygen, temperature and others. Radiosterlization of vaccine could not be performed due to the degeneration of vaccine. Cotton products were suitable where as disposable plastic set such as PVC product was not much suitable due to the reduction of pH or formation of oxidasable matter. Antibiotics in dry state was suitable where as dextrose solution or saline solution was unsuitable packing sheets (P.E, P.P, PVC) were suitable up to 2.5 Mrad dose. There was no relationships between cell growth rate and dose level in toxicity experiment of the irradiated plastic sets. Micrococcus roseus and Escherichia coli were effectively inactivated by treating heat pre-, post- or simultaneous irradiation. (author)

Hardron production and neutrino beams

Science.gov (United States)

Guglielmi, A.

2006-11-01

The precise measurements of the neutrino mixing parameters in the oscillation experiments at accelerators require new high-intensity and high-purity neutrino beams. Ancillary hadron-production measurements are then needed as inputs to precise calculation of neutrino beams and of atmospheric neutrino fluxes.

Future growth in the gamma sterilization of disposable medical products (DMPs)

International Nuclear Information System (INIS)

Brinston, R.M.

1990-01-01

An estimated 361 million cubic feet (10 million cubic meters) of disposable medical products and related health care items are currently being sterilized around the world. Ethylene oxide gas is used to treat approximately 252 million cubic feet (7.1 million cubic meters), gamma radiation is used to sterilize approximately 99 million cubic feet (2.8 million cubic meters), and electron beam is used on approximately 10 million cubic feet (0.3 million cubic meters) of disposable medical products (DMPs). Market share for each of these terminal cold sterilization processes are 70%, 27%, and 3% respectively. There are a number of factors which are affecting the overall growth of the market. The most important factors are summarized. Balancing all of these factors, the pre-sterilized disposable products market is forecasted to grow on average of 5% per year. Gamma radiation is experiencing growth from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide (EtO) to cobalt-60 sterilization. Electron beam usage while experiencing good growth in the early 1980s, is predicted to have a flat growth curve during the late 1980s, and then start to experience renewed growth in the mid to late 1990s as two or three new electron beam facilities are built. In the late 1990s other potentially competing technologies are expected to have an impact on the market place. (author)

Stress corrosion of very high purity stainless steels in alkaline media

International Nuclear Information System (INIS)

Hechmat-Dehcordi, Ebrahim

1981-01-01

This research thesis reports the study of stress corrosion resistance of stainless steels in caustic environments. It notably concerns the electronuclear industrial sector, the production of soda by electrolysis, and the preparation of hydrogen as energy vector. After a presentation of the experimental conditions, the author highlights the influence of purity on stress corrosion cracking of 20Cr-25Ni-type austenitic alloys. The specific action of a high number of addition metallic and non-metallic elements has been studied. Stress corrosion tests have been also performed in autoclave on austeno-ferritic (21 to 25 pc Cr - 6 to 10 pc Ni) as well as ferritic (26 pc Cr) grades. The author reports the study of electrochemical properties of stainless steel in soda by means of potentiostatic techniques with an application of Pourbaix thermodynamic equilibrium diagrams, and the study of the chemical composition of passivation thin layers by Auger spectroscopy. He more particularly studies the influence of electrode potential and of some addition elements on the chemical characteristics of oxides developed at the surface of austenite. Then, the author tries to establish correlations between strain hardening microstructure of the various steels and their sensitivity to stress corrosion [fr

Evaluation of bipolar pulse generator for high-purity pulsed ion beam

International Nuclear Information System (INIS)

Ito, H.; Kitamura, I.; Masugata, K.

2008-01-01

A new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)' has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the experimental results of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PEL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time. At present the bipolar pulse generator is installed in the B y type magnetically insulated ion diode and we carry out the experiment on the production of an intense pulsed ion beam by the bipolar pulse accelerator. (author)

Purity Assessment of Organic Reference Materials with a Mass Balance Method: A Case Study of Endosulfan-II

International Nuclear Information System (INIS)

Kim, Seunghyun; Lee, Joonhee; Ahn, Seonghee; Song, Youngsin; Kim, Dongkyun; Kim, Byungjoo

2013-01-01

A mass balance method established in this laboratory was applied to determine the purity of an endosulfan-II pure substance. Gas chromatography-flame ionization detector (GC-FID) was used to measure organic impurities. Total of 10 structurally related organic impurities were detected by GC-FID in the material. Water content was determined to be 0.187% by Karl-Fischer (K-F) coulometry with an oven-drying method. Nonvolatile residual impurities was not detected by Thermal gravimetric analysis (TGA) within the detection limit of 0.04% (0.7 μg in absolute amount). Residual solvents within the substance were determined to be 0.007% in the Endosulfan-II pure substance by running GC-FID after dissolving it with two solvents. The purity of the endosulfan-II was finally assigned to be (99.17 ± 0.14)%. Details of the mass balance method including interpretation and evaluating uncertainties of results from each individual methods and the finally assayed purity were also described

Internal dosimetry from IPEN workers involved in the medical radioisotopes production

International Nuclear Information System (INIS)

Cesar, R.B.P.; Mesquita, C.H. de

1988-01-01

The internal dose from IPEN workers involved in the medical radioisotopes products is related. In the workers population, six groups were classified: development and research, routine production, quality control, package, radioprotection supervision and maintenance. The internal doses were calculated according to the methodology described by the ICRP-30, using resuls from a whole-body counter. The results described were obtained from 970 whole-body radioactivity measurements during the last three years (1985 a 1987). (author) [pt

TIGRESS highly-segmented high-purity germanium clover detector

Science.gov (United States)

Scraggs, H. C.; Pearson, C. J.; Hackman, G.; Smith, M. B.; Austin, R. A. E.; Ball, G. C.; Boston, A. J.; Bricault, P.; Chakrawarthy, R. S.; Churchman, R.; Cowan, N.; Cronkhite, G.; Cunningham, E. S.; Drake, T. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Jones, B.; Leslie, J. R.; Martin, J.-P.; Morris, D.; Morton, A. C.; Phillips, A. A.; Sarazin, F.; Schumaker, M. A.; Svensson, C. E.; Valiente-Dobón, J. J.; Waddington, J. C.; Watters, L. M.; Zimmerman, L.

2005-05-01

The TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS) will consist of twelve units of four high-purity germanium (HPGe) crystals in a common cryostat. The outer contacts of each crystal will be divided into four quadrants and two lateral segments for a total of eight outer contacts. The performance of a prototype HPGe four-crystal unit has been investigated. Integrated noise spectra for all contacts were measured. Energy resolutions, relative efficiencies for both individual crystals and for the entire unit, and peak-to-total ratios were measured with point-like sources. Position-dependent performance was measured by moving a collimated source across the face of the detector.

Scientific Production of Medical Universities in the West of Iran: a Scientometric Analysis.

Science.gov (United States)

Rasolabadi, Masoud; Khaledi, Shahnaz; Khayati, Fariba; Kalhor, Marya Maryam; Penjvini, Susan; Gharib, Alireza

2015-08-01

This study aimed to compare scientific production by providing quantitative evaluation of science output in five Western Iranian Medical Universities including Hamedan, Ilam, Kermanshah, Kurdistan and Lorestan University of Medical Sciences using scientometrics indicators based on data indexed in Scopus for period between the years 2010 to 2014. In this scientometric study data were collected using Scopus database. Both searching and analyzing features of Scopus were used to data retrieval and analysis. We used Scientometrics indicators including number of publications, number of citations, nationalization index (NI), Internationalization Index (INI), H-index, average number of citations per paper, and growth index. Five Western Iranian Universities produced over 3011 articles from 2010 to 2014. These articles were cited 7158 times with an average rate of 4.2 citations per article. H- Index of under study universities are varying from 14 to 30. Ilam University of Medical Sciences had the highest international collaboration with an INI of 0.33 compared to Hamedan and Kermanshah universities with INI of 0.20 and 0.16 respectively. The lowest international collaboration belonged to Lorestan University of Medical Sciences (0.07). The highest Growth Index belonged to Kurdistan University of Medical Sciences (69.7). Although scientific production of five Western Iranian Medical Universities was increasing, but this trend was not stable. To achieve better performance it is recommended that five Western Iranian Universities stabilize their budgeting and investment policies in research.

Effect of zirconium purity on the glass-forming-ability and notch toughness of Cu{sub 43}Zr{sub 43}Al{sub 7}Be{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Andersen, Laura M. [Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA (United States); Hofmann, Douglas C. [Materials Development and Manufacturing Technology Group, NASA Jet Propulsion Laboratory/California Institute of Technology, MS 18-105, 4800 Oak Grove Dr. Pasadena, CA 91109 (United States); Vecchio, Kenneth S., E-mail: kvecchio@ucsd.edu [Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA (United States)

2016-09-30

The effect of substituting standard grade zirconium lump (99.8% excluding up to 4% hafnium) for high purity zirconium crystal bar (99.5%) in a Cu{sub 43}Zr{sub 43}Al{sub 7}Be{sub 7} bulk metallic glass (BMG) is examined. The final hafnium content in the BMG specimens was found to range from 0 to 0.44 at%. Introducing low purity zirconium significantly decreased the glass-forming-ability and reduced the notch toughness of the BMG. In contrast, when adding high purity hafnium to Cu{sub 43}Zr{sub 43}Al{sub 7}Be{sub 7} made with high purity zirconium, no significant change in the glass-forming-ability or toughness was observed. This suggests that the introduction of low purity zirconium in BMGs creates a more complex response than a simple addition of hafnium. It is likely that other impurities in the material, such as oxygen, play a role in the complex crystallization kinetics and change in mechanical properties. The notch toughness was measured through four-point-bend tests, which showed a decrease in notch toughness from an average of ~53 MPa m{sup 1/2} for the high purity samples to an average of ~29 MPa m{sup 1/2} with full substitution of low purity zirconium. A similar decrease in glass-forming-ability and toughness is observed in commercially synthesized high purity Cu{sub 43}Zr{sub 43}Al{sub 7}Be{sub 7}. The large scale commercial process is expected to introduced some unintentional impurities, which decrease the properties of the BMG in the same way as the lower purity elements. Lastly, Weibull statistics are used to provide an analysis of variability in toughness for both ingots synthesized in a small laboratory arc-melter and those synthesized commercially.

Modeling and simulation for medical product development and evaluation : highlights from the FDA-C-Path-ISOP 2013 workshop

NARCIS (Netherlands)

Romero, Klaus; Sinha, Vikram; Allerheiligen, Sandra; Danhof, Meindert; Pinheiro, Jose; Kruhlak, Naomi; Wang, Yaning; Wang, Sue-Jane; Sauer, John-Michael; Marier, J. F.; Corrigan, Brian; Rogers, James; Heerspink, H. J. Lambers; Gumbo, Tawanda; Vis, Peter; Watkins, Paul; Morrison, Tina; Gillespie, William; Gordon, Mark Forrest; Stephenson, Diane; Hanna, Debra; Pfister, Marc; Lalonde, Richard; Colatsky, Thomas

2014-01-01

Medical-product development has become increasingly challenging and resource-intensive. In 2004, the Food and Drug Administration (FDA) described critical challenges facing medical-product development by establishing the critical path initiative [1]. Priorities identified included the need for

Initial Stages of Recrystallization in Aluminum of Commercial Purity

DEFF Research Database (Denmark)

Hansen, Niels; Bay, Bent

1979-01-01

In commercial aluminum with a purity of 99.4 pct, the formation and growth of recrystallization nuclei were studied by techniques such asin-situ annealing in a high voltage electron microscope, transmission electron microscopy and light microscopy. Sample parameters were the initial grain size (370...... by the FeAl3 particles present in the commercial aluminum as impurities. The nucleation temperatures determined by high voltage electron microscopy and transmission electron microscopy decrease markedly when the initial grain size is decreased both after 50 and 90 pct cold rolling; a less pronounced...

Release characteristics of tritium from high-purity lithium oxide

International Nuclear Information System (INIS)

O'Kula, K.R.; Vogelsang, W.F.

1985-01-01

Rates of tritium release from neutronirradiated lithium oxide were determined from isothermal release experiments. High-purity, monocrystalline lithium oxide was purged ex-reactor with helium and helium-hydrogen gas streams. Overall release was found to be controlled by solid-phase diffusion, and was predominantly in the form of condensible species. The result of an independent concentration profile analysis at 923 K was in agreement with the gas release diffusion coefficient. Sweeping the Li 2 O with hydrogen-containing gas was found to enhance tritium removal during the early stage of each run

Improvement of radioisotope production technology

International Nuclear Information System (INIS)

Li Yongjian

1987-01-01

The widespreading and deepgoing applications of radioisotopes results the increasing demands on both quality and quantity. This in turn stimulating the production technology to be improved unceasingly to meet the different requirements on availability, variety, facility, purity, specific activity and specificity. The major approaches of achieving these improvements including: optimizing mode of production; enhancing irradiation conditions; amelioration target arrangement; adapting nuclear process and inventing chemical processing. (author)

Determination of the radiochemical purity of phosphorus-32 and tritium-labeled diisopropylphosphorofluoridate (DFP)

International Nuclear Information System (INIS)

Christopher, R.E.; Sheppard, G.

1975-01-01

A method is described for the determination of the radiochemical purity of labeled diisopropylphosphorofluoridate (DFP), based on the irreversible inhibition reaction with the enzyme α-chymotrypsin. The nature of the impurities in commercially available 32 P- and 3 H-labeled DFP is discussed

Medical Isotope Production at TRIUMF - from Imaging to Treatment

Science.gov (United States)

Hoehr, C.; Bénard, F.; Buckley, K.; Crawford, J.; Gottberg, A.; Hanemaayer, V.; Kunz, P.; Ladouceur, K.; Radchenko, V.; Ramogida, C.; Robertson, A.; Ruth, T.; Zacchia, N.; Zeisler, S.; Schaffer, P.

TRIUMF has a long history of medical isotope production. For more than 40 years, the Life Sciences Division at TRIUMF has produced isotopes for Positron Emission Tomography (PET) for the local hospitals. Recently, the division has taken on the challenge to expand the facility's isotope repertoire to isotopes for imaging to treatment. At the smallest cyclotron at TRIUMF with energy of 13 MeV, radiometals are being produced in a liquid target which is typically used for PET isotope production. This effort makes radiometals available for early stage research and preclinical trials. At beam energy of 24 MeV, we produce 99mTc from 100Mo with a cyclotron, the most common isotope for Single-Photon-Emission-Computed-Tomography (SPECT) and the most common isotope for nuclear imaging. The use of a cyclotron bypasses the common production route via a nuclear reactor as well as enriched uranium. And finally, at our 500 MeV cyclotron we have demonstrated the production of α emitters useful for targeted alpha therapy. Herein, these efforts are summarized.

Influence of purity level on the mechanical properties of hot isostatically pressed beryllium

International Nuclear Information System (INIS)

Odegard, B.C. Jr.

1979-09-01

The procurement of a quantity of ultra-pure beryllium powder combined with special handling from powder to billet form resulted in the fabrication of high purity beryllium. The mechanical properties of these billets were contrasted to those of commercial grade billets to determine the influence of impurities and powder processing. The tensile test results show that the strength values are primarily dependent on the grain size in a behavior predictable by the Hall-Petch relationship. Only a fraction of the strength differential can be attributed to metallic impurities in solution. The grain size is controlled by the powder size distribution. The ductility is dominated by both grain size and oxide content. The fine grained, low oxide billets exhibited the highest ductilities. There is evidence to suggest that oxide distribution has a large influence on the ductility. The fracture toughness was highest for the high purity beryllium billets

Tests of ball bearing used in high-temperature and high-purity water

International Nuclear Information System (INIS)

Leng Chengmu; Hao Shouxin.

1987-01-01

According to the particular conditions and the operation environments in high-temperature and high-purity water, the test content and the measurement instrumentation for the ball bearing were defined. Through various tests, operational performances of the bearing have preliminarily been understood. It provided some useful information for the engineering application of the bearing

High purity and semi-insulating 4H-SiC crystals grown by physical vapor transport

Energy Technology Data Exchange (ETDEWEB)

Augustine, G.; Hobgood, H.McD.; Balakrishna, V.; Dunne, G.T.; Hopkins, R.H.; Thomas, R.N. [Northrop Grumman Corp., Pittsburgh, PA (United States). Science and Technology Center; Doolittle, W.A.; Rohatgi, A. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical and Computer Engineering

1998-06-01

High purity undoped and semi-insulating vanadium doped 4H-SiC single crystals with diameters up to 50 mm were grown by the physical vapor transport method. Undoped crystals exhibiting resistivities in the 10{sup 2} to 10{sup 3} {Omega}-cm range and photoconductive decay (PCD) lifetimes in the 2 to 9 {mu}s range, were grown from high purity SiC sublimation sources. The crystals were p-type due to the presence of residual acceptor impurities, mainly boron. The semi-insulating behavior of the vanadium doped crystals is attributed to compensation of residual acceptors by the deep level vanadium donor located near the middle of the band gap. (orig.) 6 refs.

Analytic control during the production of nuclear purity compounds

International Nuclear Information System (INIS)

Caracotche de Perez, Norma; Lando, E.R.A.; Lorenzatto, R.L.P.A.; Serrichio, J.A.

1981-01-01

U02 compound is obtained from yellow cake at the Cordoba Production Complex, (Argentina). Analysis and controls during the process are described. Yellow cake is dissolved with sulphuric acid and then a leaching precipitation process originally developed in that complex takes place. In this process ammonium uranyl tricarbonate (AUC) is obtained by the addition of CO3(NH4)2 and SO4(NH4)2. During the whole process samples are sent to the laboratory for the determinations of humidity, uranium and impurities. In the solvent extraction plant determinations of Uranium are made with dibenzoilmethane and H2O2. In the fresh-eluting total amount of solids as well as Si, Fe, Ca, CO3, OH - and SO4 -- are determined. Uranium (U3O8) and carbonates are investigated in the AUTC by gravimetry, ammonium and water are obtained by Kjeldall and Xylol distillation proceses respectively. Controls of Si and Fe by colorimetry and of Ca by atomic absorption permit eventual detections of accidental contaminations. After UO3 is obtained by calcination at 300 deg C, gravimetric determination of U3O8 is made. In this step of the process, CO3, NH4, H2O, Si, Fe, Ca and SO4 -- are also detected. UO2 is the final product obtained by reduction of UO3 at 700 deg C. Physical characteristics as fluidity, apparent, TAP and real densities, half diameter of particles, granulometry and microscopic properties are verified. Normally in the UO2 process a series of routine chemical controls are made to determine U3O8, rate O/U, SO4 -- , Si, Fe Ca, Mo, Cd, Cr, Ni and water (E.A.C.) [es

Human plasma-derived immunoglobulin G fractionated by an aqueous two-phase system, caprylic acid precipitation, and membrane chromatography has a high purity level and is free of detectable in vitro thrombogenic activity.

Science.gov (United States)

Vargas, M; Segura, Á; Wu, Y-W; Herrera, M; Chou, M-L; Villalta, M; León, G; Burnouf, T

2015-02-01

Instituto Clodomiro Picado has developed an immunoglobulin G (IgG) plasma fractionation process combining a polyethylene glycol/phosphate aqueous two-phase system (ATPS), caprylic acid precipitation and anion-exchange membrane chromatography. We evaluated the purity and in vitro thrombogenicity of such IgG, in line with current international requirements. Contributions of the different production steps to reduce thrombogenicity were assessed at 0·2 l-scale, and then the methodology was scaled-up to a 10 l-scale and final products (n = 3) were analysed. Purity, immunoglobulin composition, and subclass distribution were determined by electrophoretic and immunochemical methods. The in vitro thrombogenic potential was determined by a thrombin generation assay (TGA) using a Technothrombin fluorogenic substrate. Prekallikrein activator (PKA), plasmin, factor Xa, thrombin and thrombin-like activities were assessed using S-2302, S-2251, S-2222, S-2238 and S-2288 chromogenic substrates, respectively, and FXI by an ELISA. The thrombogenicity markers were reduced mostly during the ATPS step and were found to segregate mostly into the discarded liquid upper phase. The caprylic acid precipitation eliminated the residual procoagulant activity. The IgG preparations made from the 10 l-batches contained 100% gamma proteins, low residual IgA and undetectable IgM. The IgG subclass distribution was not substantially affected by the process. TGA and amidolytic activities revealed an undetectable in vitro thrombogenic risk and the absence of proteolytic enzymes in the final product. Fractionating human plasma by an ATPS combined with caprylic acid and membrane chromatography resulted in an IgG preparation of high purity and free of a detectable in vitro thrombogenic risk. © 2014 International Society of Blood Transfusion.

Bumblebees (Bombus terrestris) and honeybees (Apis mellifera) prefer similar colours of higher spectral purity over trained colours.

Science.gov (United States)

Rohde, Katja; Papiorek, Sarah; Lunau, Klaus

2013-03-01

Differences in the concentration of pigments as well as their composition and spatial arrangement cause intraspecific variation in the spectral signature of flowers. Known colour preferences and requirements for flower-constant foraging bees predict different responses to colour variability. In experimental settings, we simulated small variations of unicoloured petals and variations in the spatial arrangement of colours within tricoloured petals using artificial flowers and studied their impact on the colour choices of bumblebees and honeybees. Workers were trained to artificial flowers of a given colour and then given the simultaneous choice between three test colours: either the training colour, one colour of lower and one of higher spectral purity, or the training colour, one colour of lower and one of higher dominant wavelength; in all cases the perceptual contrast between the training colour and the additional test colours was similarly small. Bees preferred artificial test flowers which resembled the training colour with the exception that they preferred test colours with higher spectral purity over trained colours. Testing the behaviour of bees at artificial flowers displaying a centripetal or centrifugal arrangement of three equally sized colours with small differences in spectral purity, bees did not prefer any type of artificial flowers, but preferentially choose the most spectrally pure area for the first antenna contact at both types of artificial flowers. Our results indicate that innate preferences for flower colours of high spectral purity in pollinators might exert selective pressure on the evolution of flower colours.

Production and Applications of Long-Lived Positron-Emitting Radionuclides

Science.gov (United States)

Graves, Stephen A.

Positron emission tomography (PET) is a medical imaging modality capable of determining the in vivo spatial distribution of a biologically relevant molecule which has been labeled with a positron-emitting isotope. The use of molecules such as monoclonal antibodies and nanoparticles for therapeutic and diagnostic applications has expanded preclinically in recent years. As these larger molecules tend to have longer circulation times and slow clearance kinetics, positron-emitting isotopes with half-lives longer than conventional medical radioisotopes are required for PET applications. This dissertation details methods for the production of 51Mn (t1/2: 45.4 min), 52gMn (t1/2: 5.59 d), 64Cu (t1/2: 12.7 h), 76Br (t1/2: 16.2 h), 89Zr (t1/2: 3.27 d), and 194Au (t1/2: 38.0 h) on low-energy medical cyclotrons, including targetry considerations, radiochemical separation methods, and analysis of resulting purity. Pursuant to the production of these isotopes, several instrumentation developments have been made including implementation of an automatic nuclide identification library for gamma spectroscopy; development of methods for dead time correction and background estimation in auto-gamma counting; and the creation of a new linearly-filled Derenzo-type PET phantom. Measurement of the radioactive half-lives of 51Mn and 52gMn are presented in addition to their use in a variety of preclinical molecular imaging applications, including immunoPET, stem cell tracking, functional beta-cell mass determination, and probing the impact of isoflurane on acute pancreatic function. An analytic model of effective specific activity is formed and tested against preliminary trace metal analysis results. Measurements of excitation functions for the large-scale production of medically relevant isotopes, including 52gMn, at the Los Alamos National Laboratory Isotope Production Facility (100 MeV p+) are presented. The results described herein have enabled and informed a variety of novel

High Resolution Gamma Ray Analysis of Medical Isotopes

Science.gov (United States)

Chillery, Thomas

2015-10-01

Compton-suppressed high-purity Germanium detectors at the University of Massachusetts Lowell have been used to study medical radioisotopes produced at Brookhaven Linac Isotope Producer (BLIP), in particular isotopes such as Pt-191 used for cancer therapy in patients. The ability to precisely analyze the concentrations of such radio-isotopes is essential for both production facilities such as Brookhaven and consumer hospitals across the U.S. Without accurate knowledge of the quantities and strengths of these isotopes, it is possible for doctors to administer incorrect dosages to patients, thus leading to undesired results. Samples have been produced at Brookhaven and shipped to UML, and the advanced electronics and data acquisition capabilities at UML have been used to extract peak areas in the gamma decay spectra. Levels of Pt isotopes in diluted samples have been quantified, and reaction cross-sections deduced from the irradiation parameters. These provide both cross checks with published work, as well as a rigorous quantitative framework with high quality state-of-the-art detection apparatus in use in the experimental nuclear physics community.

New vacancy source in ultrahigh-purity aluminium single crystals with a low dislocation density

Energy Technology Data Exchange (ETDEWEB)

Mizuno, Kaoru; Yamamoto, Satoshi [Shimane Univ., Faculty of Science and Engineering, Matsue, Shimane (Japan); Morikawa, Kimihiko [Hokkaido Univ., Institute for Low Temperature Science, Sapporo, Hokkaido (Japan); Kuga, Masanori [Kanazawa Univ., Faculty of Science, Kanazawa, Ishikawa (Japan); Okamoto, Hiroyuki [Kanazawa Univ., Faculty of Medicine, Kanazawa, Ishikawa (Japan); Hashimoto, Eiji [Hiroshima Univ., Hiroshima Synchrotron Radiation Center, Higashi-Hiroshima, Hiroshima (Japan)

2004-05-01

The vacancy generation process in ultrahigh-purity aluminum single crystals with a low dislocation density was investigated by synchrotron radiation topography using a white X-ray beam. Some straight lines were observed in the topographys taken after temperature rose to 300degC from room temperature, and they were confirmed to be rows of successive small interstitial-type dislocation loops grown as vacancy sources. It was concluded that the thermal generation mechanism of vacancies in ultrahigh-purity aluminum single crystals with a low dislocation density consists of the following two steps. First, small interstitial loops are heterogeneously formed in the crystal lattice; second, these convert to lengthened loops with the development of screw components and finally grow into rows of dislocation loops emitting vacancies into the lattice. (author)

New vacancy source in ultrahigh-purity aluminium single crystals with a low dislocation density

International Nuclear Information System (INIS)

Mizuno, Kaoru; Yamamoto, Satoshi; Morikawa, Kimihiko; Kuga, Masanori; Okamoto, Hiroyuki; Hashimoto, Eiji

2004-01-01

The vacancy generation process in ultrahigh-purity aluminum single crystals with a low dislocation density was investigated by synchrotron radiation topography using a white X-ray beam. Some straight lines were observed in the topographys taken after temperature rose to 300degC from room temperature, and they were confirmed to be rows of successive small interstitial-type dislocation loops grown as vacancy sources. It was concluded that the thermal generation mechanism of vacancies in ultrahigh-purity aluminum single crystals with a low dislocation density consists of the following two steps. First, small interstitial loops are heterogeneously formed in the crystal lattice; second, these convert to lengthened loops with the development of screw components and finally grow into rows of dislocation loops emitting vacancies into the lattice. (author)

Comparison of Deformation in High-Purity Single/Large Grain and Polycrystalline Niobium Superconducting Cavities

International Nuclear Information System (INIS)

Ganapati Rao Myneni; Peter Kneisel

2005-01-01

The current approach for the fabrication of superconducting radio frequency (SRF) cavities is to roll and deep draw sheets of polycrystalline high-purity niobium. Recently, a new technique was developed at Jefferson Laboratory that enables the fabrication of single-crystal high-purity Nb SRF cavities. To better understand the differences between SRF cavities fabricated out of fine-grained polycrystalline sheet in the standard manner and single crystal cavities fabricated by the new technique, two half-cells were produced according to the two different procedures and compared using a variety of analytical techniques including optical microscopy, scanning laser confocal microscopy, profilometry, and X-ray diffraction. Crystallographic orientations, texture, and residual stresses were determined in the samples before and after forming and this poster presents the results of this ongoing study

Fashion Brand Purity and Firm Performance

Directory of Open Access Journals (Sweden)

Jin-hui Zheng

2013-01-01

Full Text Available A large number of prior empirical research and case studies used qualitative methodology to discuss the fashion brand dilution resulting from consumer base extension from the target group(s to the nontarget groups and its impacts. From a different perspective, this paper establishes a dynamic brand dilution and performance model, demonstrating how dynamic changes of sales volumes involving the two consumer groups affect the degree of brand dilution and the performance of the brand. We incorporate the factor “brand purity” to the model as a quantitative measure of brand dilution level that affects firm annual revenue and profit change comprehensively in iteration. Our model suggests that fashion brands, especially luxury brands, can be easily diluted under the pressure of firm growth, and the brands suffer the significant negative impact on their revenues and profit. While increasing sales volume can aggravate the negative consequences, brand purity can be increased through limiting the consumer base to the target group only.

Encountering Challenges with the EU Regulation on Advance Therapy Medical Products.

Science.gov (United States)

Mansnérus, Juli

2015-12-01

This article aims at analysing how well the Advanced Therapy Medical Product Regulation (EC) No. 1394/2007 (ATMP Regulation) meets the needs of small and medium-sized enterprises (SMES), academia and public tissue establishments developing advanced therapy medical products (ATMPS). Benefits and shortcomings of the ATMP Regulation are identified, and possible amendments are proposed to accelerate the translation of research into advanced therapies and to facilitate the commercialisation of ATMPS whilst ensuring safety. It was set up as a lex specialis to ensure the free movement of ATMPS within the EU in order to facilitate their access to the internal market and to foster the competitiveness of European pharmaceutical companies, while guaranteeing the highest level protection of public health. Since the adoption of the ATMP Regulation in late 2008, only 5 ATMPS have been granted marketing authorisations thus far. Hence, there is a need to analyse whether the ATMP Regulation meets its objectives.

The medical effects of radioactive fall-out: role of stable end-products

International Nuclear Information System (INIS)

Burrows, B.A.; Cardarelli, J.C.; Boling, E.A.; Sinex, F.M.

1980-01-01

To summarize, from preliminary observations on the possible effects of radioactive fall-out, it may be inferred that in addition to the secondary products of ionizing irradiation per se, the stable end-products of the transmutation of certain radionuclides may adversely influence cellular metabolism, including mutagenesis. The discussion of the possible role of intracellular barium as an end-product of 137Cs decay is offered as an example of an unpredictable number of broad ecological, as well as the more limited medical, effects that may be of both clinical and climatological significance

Developing role of short-lived radionuclides in nuclear medical practice. DOE symposium series; 56

International Nuclear Information System (INIS)

Paras, P.; Thiessen, J.W.

1985-01-01

The purpose was to define the developing role and state-of-the-art development of short-lived radionuclides (SLR's) in current nuclear medical practice. Special emphasis was placed on radionuclides with general-purpose labeling capabilities. The need for high-purity labeling-grade iodine-123 was emphasized in the program. Papers have been separately abstracted for the data base

Adoption of Falsified Medical Products in a Low-Income Country : Empirical Evidence for Suriname

NARCIS (Netherlands)

Ph.H.B.F. Franses (Philip Hans); M.M. Lede (Madesta)

2017-01-01

markdownabstractBased on detailed shipping figures for Suriname’s main harbour in Paramaribo, we estimate the total shipments (in kilograms) of original and falsified medical products for 1996–2008 across five product categories. Using various time series techniques and diffusion models, we document

Radiosterilization of Medical Products and Recommended Code of Practice. Proceedings of a Symposium

Energy Technology Data Exchange (ETDEWEB)

NONE

1967-09-15

Proceedings of a Symposium organized by the IAEA and held in Budapest, 5-9 June 1967, together with the IAEA recommended 'Code of Practice for Radiosterilization of Medical Products' resulting from a panel meeting held in Vienna, December 1966, and considered at the Symposium. The meeting was attended by 160 participants from 25 Member States and 3 international organizations. The commercial use of ionizing radiation for sterilizing medical supplies extends back to the early 1960s. The ability of the process to sterilize products made of materials such as plastics, which are destroyed by traditional sterilization procedures, has promoted much new thinking in product design. Most important is the ability of the radiation to sterilize items finally sealed and packed for dispatch, eliminating risk of recontamination. Some new fields of research are discussed in the Proceedings. The Code of Practice, drawn up by experts at several meetings, is aimed at producing uniform, safe procedures throughout the world, facilitating international trade in radiosterilized products. Contents: Introductory lecture; Radiosterilization of pharmaceuticals and bioproducts (12 papers); Radiosterilization of biological tissues (6 papers); Vaccine production by ionizing radiation (5 papers); Radiosterilization of medical devices and supplies (4 papers); Radiosensitivity of micro-organisms and microbiological testing (4 papers); Technical and economic aspects of radiosterilization (6 papers); Code of practice for radiosterilization (full code and 1 review paper). The Code of Practice is in English. Each paper is in its original language (29 English, 5 French, 4 Russian and 1 Spanish) and is preceded by an abstract in English with one in the original language if this is not English. Discussions are in English. (author)

Radiosterilization of Medical Products and Recommended Code of Practice. Proceedings of a Symposium

International Nuclear Information System (INIS)

1967-01-01

Proceedings of a Symposium organized by the IAEA and held in Budapest, 5-9 June 1967, together with the IAEA recommended 'Code of Practice for Radiosterilization of Medical Products' resulting from a panel meeting held in Vienna, December 1966, and considered at the Symposium. The meeting was attended by 160 participants from 25 Member States and 3 international organizations. The commercial use of ionizing radiation for sterilizing medical supplies extends back to the early 1960s. The ability of the process to sterilize products made of materials such as plastics, which are destroyed by traditional sterilization procedures, has promoted much new thinking in product design. Most important is the ability of the radiation to sterilize items finally sealed and packed for dispatch, eliminating risk of recontamination. Some new fields of research are discussed in the Proceedings. The Code of Practice, drawn up by experts at several meetings, is aimed at producing uniform, safe procedures throughout the world, facilitating international trade in radiosterilized products. Contents: Introductory lecture; Radiosterilization of pharmaceuticals and bioproducts (12 papers); Radiosterilization of biological tissues (6 papers); Vaccine production by ionizing radiation (5 papers); Radiosterilization of medical devices and supplies (4 papers); Radiosensitivity of micro-organisms and microbiological testing (4 papers); Technical and economic aspects of radiosterilization (6 papers); Code of practice for radiosterilization (full code and 1 review paper). The Code of Practice is in English. Each paper is in its original language (29 English, 5 French, 4 Russian and 1 Spanish) and is preceded by an abstract in English with one in the original language if this is not English. Discussions are in English. (author)

Deuterium permeation and diffusion in high-purity beryllium

International Nuclear Information System (INIS)

Abramov, E.; Riehm, M.P.; Thompson, D.A.; Smeltzer, W.W.

1990-01-01

The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. Using multilayer permeation theory the effects of surface oxide were eliminated and the diffusion coefficients of the bulk beryllium determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 =6.7x10 -9 m 2 /s and E D =28.4 kJ/mol. For the high-grade beryllium samples (99%) the parameters are D 0 =8.0x10 -9 m 2 /s and E D =35.1 kJ/mol. (orig.)

Methods to improve and understand the sensitivity of high purity germanium detectors for searches of rare events

International Nuclear Information System (INIS)

Volynets, Oleksandr

2012-01-01

Observation of neutrinoless double beta-decay could answer fundamental questions on the nature of neutrinos. High purity germanium detectors are well suited to search for this rare process in germanium. Successful operation of such experiments requires a good understanding of the detectors and the sources of background. Possible background sources not considered before in the presently running GERDA high purity germanium detector experiment were studied. Pulse shape analysis using artificial neural networks was used to distinguish between signal-like and background-like events. Pulse shape simulation was used to investigate systematic effects influencing the efficiency of the method. Possibilities to localize the origin of unwanted radiation using Compton back-tracking in a granular detector system were examined. Systematic effects in high purity germanium detectors influencing their performance have been further investigated using segmented detectors. The behavior of the detector response at different operational temperatures was studied. The anisotropy effects due to the crystallographic structure of germanium were facilitated in a novel way to determine the orientation of the crystallographic axes.

Methods to improve and understand the sensitivity of high purity germanium detectors for searches of rare events

Energy Technology Data Exchange (ETDEWEB)

Volynets, Oleksandr

2012-07-27

Observation of neutrinoless double beta-decay could answer fundamental questions on the nature of neutrinos. High purity germanium detectors are well suited to search for this rare process in germanium. Successful operation of such experiments requires a good understanding of the detectors and the sources of background. Possible background sources not considered before in the presently running GERDA high purity germanium detector experiment were studied. Pulse shape analysis using artificial neural networks was used to distinguish between signal-like and background-like events. Pulse shape simulation was used to investigate systematic effects influencing the efficiency of the method. Possibilities to localize the origin of unwanted radiation using Compton back-tracking in a granular detector system were examined. Systematic effects in high purity germanium detectors influencing their performance have been further investigated using segmented detectors. The behavior of the detector response at different operational temperatures was studied. The anisotropy effects due to the crystallographic structure of germanium were facilitated in a novel way to determine the orientation of the crystallographic axes.

Rare earth impurities in high purity lanthanum oxide determined by neutron activation analysis

International Nuclear Information System (INIS)

Nguyen Van Suc; Desai, H.B.; Parthasarathy, R.; Gangadharan, S.

1992-01-01

Individual rare earth impurities in high purity La 2 O 3 (≥99.9%) have been determined by NAA after pre-separation of the matrix (La). The separation is carried out on an anion exchanger (Dowex 1x8) using different mixtures of methanol/nitric acid as eluants. The rare earth elements from Dy to Lu are eluted quantitatively using a 10% 1M HNO 3 - 90% methanol mixture, while the light rare earths from Ce to Gd are eluted quantitatively using a 10% 0.05M HNO 3 - 90% methanol mixture. La, which is retained on the column, is eluted using 0.1M HNO 3 . The recoveries of the various rare earth elements have been checked using radiotracers and also by spiking the sample with known amount of elements, and the recoveries are found to be quantitative. Results obtained on a typical high purity lanthanum oxide are reported here. (author) 5 refs.; 1 fig

Preparation of High Purity CdTe for Nuclear Detector: Electrical and Nuclear Characterization

Science.gov (United States)

Zaiour, A.; Ayoub, M.; Hamié, A.; Fawaz, A.; Hage-ali, M.

High purity crystal with controllable electrical properties, however, control of the electrical properties of CdTe has not yet been fully achieved. Using the refined Cd and Te as starting materials, extremely high-purity CdTe single crystals were prepared by the traditional vertical THM. The nature of the defects involved in the transitions was studied by analyzing the position of the energy levels by TSC method. The resolution of 4.2 keV (FWHM) confirms the high quality and stability of the detectors: TSC spectrum was in coherence with detectors spectrum with a horizontal plate between 0.2 and 0.6 eV. The enhancement in resolution of detectors with a full width at half- maximum (less than 0.31 meV), lead to confirm that the combination of vacuum distillation and zone refining was very effective to obtain more purified CdTe single crystals for photovoltaic or nuclear detectors with better physical properties.

Trend report on international and Japanese standardization activities for bioceramics and tissue engineered medical products

Directory of Open Access Journals (Sweden)

Sadami Tsutsumi

2010-01-01

Full Text Available Since porous and injectable bioceramics have recently been utilized often as scaffolds for bone regenerative medicine, the need for their standardization has increased. One of the standard proposals in ISO/TC150 and JIS has been a draft for characterization of the porous bioceramic scaffolds in both micro- and macro-scopic aspects. ISO/TC150/SC7 (Tissue engineered medical products has been co-chaired by Professor J E Lemons, Department of Surgery, University of Alabama at Birmingham and Dr R Nakaoka, Division of Medical Devices, National Institute of Health Sciences, Japan. The scope of SC7 has been specified as 'Standardization for the general requirements and performance of tissue engineered medical products with the exclusion of gene therapy, transplantation and transfusion'.

Medical application of nuclear science: nuclear medicine and production of radiopharmaceuticals

International Nuclear Information System (INIS)

Cornet, L.

1997-01-01

Nuclear science in attendance on medicine or from Radium to Radiopharmaceuticals. By a brief historical reminder of the evolution of the radioactivity and development of nuclear science, we could see a very early interest and application of the radioactivity in the medical field. Main steps: Detection of natural radioactivity/Discovery of artificial radioactivity/First treatment of leukaemia and thyroid/First nuclear reactor/First radioisotope laboratory in hospital/First scintigraphy/First radiopharmaceutical/First cyclotron and cyclotron products/First immunoscintigraphy/Biotechnology and radioisotope/Evolution of technics [equipment for diagnosis (imaging, scintigraphy) and therapy]/Evolution of production technics and concept of products (generators of Technetium) and machines, reactor, cyclotron/Evolution of importance and interest of nuclear medicine/Creation of international association of nuclear medicine and producers (example ARPR)/Evolution of safety and pharmaceuticals regulation. After the sixties, period extremely rich in invention of products, characterized by a high fertility specially due to a non-restrictive regulation in terms of safety and pharmaceutical consideration, the evolution of technics, the importance of costs (investment, research, healthcare and the evolution of the regulations) have smoothly but continuously transformed the contexts and different actors. Consequences and facts: Rationalization and standardization of the catalogues, total integration of radiopharmaceuticals into the pharmaceutical laws, stop of nuclear research reactors, increase of number of cyclotrons, transformation of size and role of the producers and nuclear centers, risk in supply of some raw materials like Molybdenum, medical nuclear application as a worldwide business

Amplitude dependent damping in single crystalline high purity molybdenum

International Nuclear Information System (INIS)

Zelada-Lambri, G.I; Lambri, O.A; Garcia, J.A; Lomer, J.N

2004-01-01

Amplitude dependent damping measurements were performed on high purity single crystalline molybdenum at several different constant temperatures between room temperature and 1273K. The employed samples were single crystals with the orientation, having a residual resistivity ratio of about 8000. Previously to the amplitude dependent damping tests, the samples were subjected to different thermomechanical histories. Amplitude dependent damping effects appear only during the first heating run in temperature where the samples have the thermomechanical state of the deformation process at room temperature. In the subsequent run-ups in temperature, i.e, after subsequent annealings, amplitude dependent damping effects were not detected (au)

Obtention of high purity silica from the flotation waste of itabiritic ore; Obtencao de silica de elevada pureza a partir do rejeito de flotacao de um minerio itabiritico

Energy Technology Data Exchange (ETDEWEB)

Martins, Polyana Fabricia Fernandes

2016-10-01

Banded iron formations are exploited as iron mineral in 'Quadrilatero Ferrifero' of Minas Gerais (MG) State, Brazil. About half of the amount of extracted material becomes tailings, which are stored in tailing dams or used for filling mining pits. Tens of thousands of tons are generated daily in operating mines in this region, causing concern about the environmental liabilities, and costs to manage the tailing dams. Miners are committed to finding uses for these wastes in other productive chains. This thesis aimed to obtain high purity silica from the flotation tailings of banded iron formations using classical techniques for ore processing, such as particle size classification and magnetic separation, followed by hydrometallurgical leaching, also alkaline fusion and chemical precipitation. The tailings samples was collected in the tailings dam of Peak Mine operated by Vale A.S., in Itabirito – MG. This sample had initially 33.4% by weight SiO{sub 2}, 57.4% wt Fe{sub 2}O{sub 3} and 8.31% wt Al{sub 2}O{sub 3}. After desliming for disposal of the fine particles (-37μm) the composition was 68.0% SiO{sub 2}, 31.4% Fe{sub 2}O{sub 3} and 0.50% Al{sub 2}O{sub 3}. After magnetic separation, the composition was 93.8% SiO{sub 2}, 1.16% Fe{sub 2}O{sub 3} and 3.80% Al{sub 2}O{sub 3}. After acid leaching l or digestion to remove impurities, it was possible to obtain silica with 98% purity. The fusion with sodium hydroxide, followed by alkaline leaching of sodium silicate and silica precipitation gave purities of about 99.5%. Values even higher may be possible with optimization of the parameters of alkaline fusion or by repeating the process from the product with purity of 99.5%. The iron oxide content and the aluminum main contaminants were 0.01% and 0.07%, respectively. Amorphous silica was obtained with high specific surface (322 m{sup 2}/g) and particle size less than 200 nm. Depending on the application, a control should be made for the impurities, such as

Technical meeting of project counterparts on 'Cyclotron production of Iodine-123'. Report

International Nuclear Information System (INIS)

2002-01-01

Several cyclotron laboratory facilities are very much interested in the production of Iodine-123 for medical applications in view of its optimal physical and chemical properties. Some of these countries have in the past used the solid target technology based on utilization of enriched Tellurium targets and are currently involved in the development of enriched Xenon-124 gas targets to improved radionuclidic purity as required by the needs of modern nuclear medicine. With the purpose of discussing the advances in the later route of production and to foster mutual co-operation among the developing countries interested in this technology, a meeting was convened with the participation of scientists from Argentina, Brazil, Iran, Korea and Syria. A scientist from the United States was also invited as an expert to provide advise on particular aspects of the technology. This publication contains as an annex technical reports from the participating institutions. All of these reports have been separately indexed and provided with abstracts

Sugar beet genotype effect on potential of bioethanol production ...

African Journals Online (AJOL)

Variation on ethanol production were intensively related to the chemical composition of root, especially sugar content, potassium impurity, syrup purity and some characteristics such as root dry matter and root length. Bioethanol production was enhanced by increasing the sugar content and root yield in sugar beet. Sugar ...

The effect of the purity and of the materials used for adapters on the purification of yttrium by solid state electrotransport

International Nuclear Information System (INIS)

Nikoforova, T.V.; Volkov, V.T.

1986-01-01

The influence of tantalum, molybdenum and zirconium adapters on the efficiency of the solid state electrotransport process is investigated with a view to increasing the quality and purity of yttrium. The degree and direction of metallic impurity electromigration in the given metals were studied. The impurities in question were shown to move in different directions depending on the type of adapter. Recommendations for the application of adapters according to their purity are given. The application of high purity tantalum as anode and cathode adapters in three-stage solid state electrotransport enabled us to obtain yttrium single crystals with a ratio of resistance at room temperature to that at helium temperatures of 1200. (orig.)

Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

Energy Technology Data Exchange (ETDEWEB)

Shwetha Ramkumar; Mahesh Iyer; Danny Wong; Himanshu Gupta; Bartev Sakadjian; Liang-Lhih Fan

2008-09-30

High purity hydrogen is commercially produced from syngas by the Water Gas Shift Reaction (WGSR) in high and low temperature shift reactors using iron oxide and copper catalysts respectively. However, the WGSR is thermodynamically limited at high temperatures towards hydrogen production necessitating excess steam addition and catalytic operation. In the calcium looping process, the equilibrium limited WGSR is driven forward by the incessant removal of CO{sub 2} by-product through the carbonation of calcium oxide. At high pressures, this process obviates the need for a catalyst and excess steam requirement, thereby removing the costs related to the procurement and deactivation of the catalyst and steam generation. Thermodynamic analysis for the combined WGS and carbonation reaction was conducted. The combined WGS and carbonation reaction was investigated at varying pressures, temperatures and S/C ratios using a bench scale reactor system. It was found that the purity of hydrogen increases with the increase in pressure and at a pressure of 300 psig, almost 100% hydrogen is produced. It was also found that at high pressures, high purity hydrogen can be produced using stoichiometric quantities of steam. On comparing the catalytic and non catalytic modes of operation in the presence of calcium oxide, it was found that there was no difference in the purity of hydrogen produced at elevated pressures. Multicyclic reaction and regeneration experiments were also conducted and it was found that the purity of hydrogen remains almost constant after a few cycles.

Gamma sterilization of disposable medical products (DMP's)

International Nuclear Information System (INIS)

Brinston, R.M.

1990-01-01

Ten million cubic meters (361 million cubic feet) of disposable medical products (DMP) and related health care items are estimated to be sterilized in the world. In this paper, current conditions and perspectives of gamma sterilization is discussed in comparison with ethylene oxide gas and electron beams. Of the total sterilization estimates for DMP, 2.8 million cubic meters (99 million cubic feet) are sterilized with gamma radiation, with a market share of 27%. Gamma radiation is becoming increased from both general market growth and the introduction of new products, as well as the conversion of product from ethylene oxide gas to cobalt-60. Regulatory pressures, legal considerations, and increasing publicity surrounding ethylene oxide usage are encouraging manufactures to switch to gamma radiation. Gamma's performance features include: no temperature change during the sterilization, high penetration, even through hermetically sealed packages, no residues, and no post-sterilization treatment or quarantine period. Gamma sterilization is economically beneficial in large volumes of product. Cost saving to the end user of gamma sterilization has meant lower minimum dose levels than 25 KGy. Despite of an increasingly accepted gamma radiation, there are still four factors to be considered, including cobalt-60 availability, price, transportation, and disposal. The price of cobalt-60 is based on neutron cost. In the future, cobalt-60 price is expected to be flat and enables gamma processing to become even more competitive with other sterilization methods. Gamma radiation using cobalt-60 has been proven as a safe, effective, and cost-competitive sterilization method for treating DMP and related health care items. It's wide use and many processing advantages will continue to make it a preferred sterilization method. (N.K.)

Production capabilities in US nuclear reactors for medical radioisotopes

Energy Technology Data Exchange (ETDEWEB)

Mirzadeh, S.; Callahan, A.P.; Knapp, F.F. Jr. (Oak Ridge National Lab., TN (United States)); Schenter, R.E. (Westinghouse Hanford Co., Richland, WA (United States))

1992-11-01

The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the radioisotopes required for DOE-supported radionuclide generators were made available at the Brookhaven National Laboratory (BNL) High Flux Beam Reactor (HFBR). In March 1988, however, the HFBR was temporarily shut down which forced investigators to look at other reactors for production of the radioisotopes. During this period the Missouri University Research Reactor (MURR) played an important role in providing these services. The HFIR resumed routine operation in July 1990 at 85 MW power, and the HFBR resumed operation in June 1991, at 30 MW power. At the time of the HFBR shutdown, there was no available comprehensive overview which could provide information on status of the reactors operating in the US and their capabilities for radioisotope production. The obvious need for a useful overview was thus the impetus for preparing this survey, which would provide an up-to-date summary of those reactors available in the US at both the DOE-funded national laboratories and at US universities where service irradiations are currently or expected to be conducted.

Production capabilities in US nuclear reactors for medical radioisotopes

International Nuclear Information System (INIS)

Mirzadeh, S.; Callahan, A.P.; Knapp, F.F. Jr.; Schenter, R.E.

1992-11-01

The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the radioisotopes required for DOE-supported radionuclide generators were made available at the Brookhaven National Laboratory (BNL) High Flux Beam Reactor (HFBR). In March 1988, however, the HFBR was temporarily shut down which forced investigators to look at other reactors for production of the radioisotopes. During this period the Missouri University Research Reactor (MURR) played an important role in providing these services. The HFIR resumed routine operation in July 1990 at 85 MW power, and the HFBR resumed operation in June 1991, at 30 MW power. At the time of the HFBR shutdown, there was no available comprehensive overview which could provide information on status of the reactors operating in the US and their capabilities for radioisotope production. The obvious need for a useful overview was thus the impetus for preparing this survey, which would provide an up-to-date summary of those reactors available in the US at both the DOE-funded national laboratories and at US universities where service irradiations are currently or expected to be conducted

RESEARCH ON MICROBIOLOGICAL PURITY OF “PHYTOPROST” AND “TAMSULOPROST” SUPPOSITORIES

Directory of Open Access Journals (Sweden)

Gritsenko V. I.

2014-01-01

Full Text Available Results of the tests on microbiological purity of the test samples of "Tamsuloprost" and "Phytoprost" suppositories for the treatment of prostate diseases have shown that no viable cells of fungi were found in the preparations, the number of viable cells of microorganisms is within a norman rate. Studying the effectiveness of antimicrobial preservatives it was found that the test samples meet criterion of the requirements of the State Pharmacopoeia of Ukraine.

APPARATUS FOR THE PRODUCTION OF LITHIUM METAL

Science.gov (United States)

Baker, P.S.; Duncan, F.R.; Greene, H.B.

1961-08-22

Methods and apparatus for the production of high-purity lithium from lithium halides are described. The apparatus is provided for continuously contacting a molten lithium halide with molten barium, thereby forming lithium metal and a barium halide, establishing separate layers of these reaction products and unreacted barium and lithium halide, and continuously withdrawing lithium and barium halide from the reaction zone. (AEC)

Large-scale synthesis of high-purity well-aligned carbon nanotubes using pyrolysis of iron(II) phthalocyanine and acetylene

Science.gov (United States)

Liu, B. C.; Lee, T. J.; Lee, S. H.; Park, C. Y.; Lee, C. J.

2003-08-01

Well-aligned carbon nanotubes (CNTs) with high purity have been produced by pyrolysis of iron(II) phthalocyanine and acetylene at 800 °C. The synthesized CNTs have a length of 75 μm and diameters ranging from 20 to 60 nm. The CNTs have a bamboo-like structure and exhibit good crystallinity of graphite sheets. The growth rate of the CNTs was rapidly increased with adding C 2H 2. Our results demonstrate that the proposed growth method is suitable to large-scale synthesis of high-purity well-aligned CNTs on various substrates.

Determination of Ergot Alkaloids: Purity and Stability Assessment of Standards and Optimization of Extraction Conditions for Cereal Samples

DEFF Research Database (Denmark)

Krska, R.; Berthiller, F.; Schuhmacher, R.

2008-01-01

as those that are the most common and physiologically active. The purity of the standards was investigated by means of liquid chromatography with diode array detection, electrospray ionization, and time-of-flight mass spectrometry (LC-DAD-ESI-TOF-MS). All of the standards assessed showed purity levels...... (PSA) before LC/MS/MS. Based on the results obtained from these optimization studies, a mixture of acetonitrile with ammonium carbonate buffer was used as extraction solvent, as recoveries for all analyzed ergot alkaloids were significantly higher than those with the other solvents. Different sample...

Deuterium permeation and diffusion in high purity beryllium

International Nuclear Information System (INIS)

Abramov, E.

1990-05-01

The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. A multilayer permeation theory was used in order to eliminate the surface oxide effects and the diffusion coefficients of the bulk beryllium were determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 = 6.7 x 10 -9 [m 2 /s] and E D = 28.4 [KJ/mol]; and for the high-grade beryllium samples (99%) the parameters are D 0 = 8.0 x 10 -9 [m 2 /s] and E D = 35.1 [KJ/mol

Study of corrosion of aluminium alloys of nuclear purity in ordinary water, пart one

Directory of Open Access Journals (Sweden)

Pešić Milan P.

2004-01-01

Full Text Available Effects of corrosion of aluminum alloys of nuclear purity in ordinary water of the spent fuel storage pool of the RA research reactor at VINČA Institute of Nuclear Sciences has been examined in the frame work of the International Atomic Energy Agency Coordinated Research Project "Corrosion of Research Reactor Aluminum-Clad Spent Fuel in Water" since 2002. The study presented in this paper comprises activities on determination and monitoring of chemical parameters and radio activity of water and sludge in the RA spent fuel storage pool and results of the initial study of corrosion effects obtained by visual examinations of surfaces of various coupons made of aluminum alloys of nuclear purity of the test racks exposed to the pool water for a period from six months to six years.

A light hydrocarbon fuel processor producing high-purity hydrogen

Science.gov (United States)

Löffler, Daniel G.; Taylor, Kyle; Mason, Dylan

This paper discusses the design process and presents performance data for a dual fuel (natural gas and LPG) fuel processor for PEM fuel cells delivering between 2 and 8 kW electric power in stationary applications. The fuel processor resulted from a series of design compromises made to address different design constraints. First, the product quality was selected; then, the unit operations needed to achieve that product quality were chosen from the pool of available technologies. Next, the specific equipment needed for each unit operation was selected. Finally, the unit operations were thermally integrated to achieve high thermal efficiency. Early in the design process, it was decided that the fuel processor would deliver high-purity hydrogen. Hydrogen can be separated from other gases by pressure-driven processes based on either selective adsorption or permeation. The pressure requirement made steam reforming (SR) the preferred reforming technology because it does not require compression of combustion air; therefore, steam reforming is more efficient in a high-pressure fuel processor than alternative technologies like autothermal reforming (ATR) or partial oxidation (POX), where the combustion occurs at the pressure of the process stream. A low-temperature pre-reformer reactor is needed upstream of a steam reformer to suppress coke formation; yet, low temperatures facilitate the formation of metal sulfides that deactivate the catalyst. For this reason, a desulfurization unit is needed upstream of the pre-reformer. Hydrogen separation was implemented using a palladium alloy membrane. Packed beds were chosen for the pre-reformer and reformer reactors primarily because of their low cost, relatively simple operation and low maintenance. Commercial, off-the-shelf balance of plant (BOP) components (pumps, valves, and heat exchangers) were used to integrate the unit operations. The fuel processor delivers up to 100 slm hydrogen >99.9% pure with <1 ppm CO, <3 ppm CO 2. The

High-Purity Fe3S4 Greigite Microcrystals for Magnetic and Electrochemical Performance

NARCIS (Netherlands)

Li, Guowei; Zhang, Baomin; Yu, Feng; Novakova, Alla A.; Krivenkov, Maxim S.; Kiseleva, Tatiana Y.; Chang, Liao; Rao, Jiancun; Polyakov, Alexey O.; Blake, Graeme R.; de Groot, Robert A.; Palstra, Thomas T. M.

2014-01-01

High-purity Fe3S4 (greigite) microcrystals with octahedral shape were synthesized via a simple hydrothermal method using a surfactant. The as-prepared samples have the inverse spinel structure with high crystallinity. The saturation magnetization (M-s) reaches 3.74 mu(B) at 5 K and 3.51 mu(B) at

A conversion development program to LEU targets for medical isotope production in the MAPLE Facilities

International Nuclear Information System (INIS)

Malkoske, G.R.

2000-01-01

Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada has been extracted from reactor targets employing highly enriched uranium (HEU). The molybdenum extraction process from the HEU targets provided predictable, consistent yields for our high-volume molybdenum production process. A reliable supply of HEU for the NRU research reactor targets has enabled MDS Nordion to develop a secure chain of medical isotope supply for the international nuclear medicine community. Each link of the isotope supply chain, from isotope production to patient application, has been established on a proven method of HEU target irradiation and processing. To ensure a continued reliable and timely supply of medical isotopes, the design of the MAPLE facilities was based on our established process - extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a program to convert the MAPLE facilities to LEU targets. An initial feasibility study was initiated to identify the technical issues to convert the MAPLE targets from HEU to LEU. This paper will present the results of the feasibility study. It will also describe future challenges and opportunities in converting the MAPLE facilities to LEU targets for large scale, commercial medical isotope production. (author)

Mapping medical marijuana: state laws regulating patients, product safety, supply chains and dispensaries, 2017.

Science.gov (United States)

Klieger, Sarah B; Gutman, Abraham; Allen, Leslie; Pacula, Rosalie Liccardo; Ibrahim, Jennifer K; Burris, Scott

2017-12-01

(1) To describe open source legal data sets, created for research use, that capture the key provisions of US state medical marijuana laws. The data document how state lawmakers have regulated a medicine that remains, under federal law, a Schedule I illegal drug with no legitimate medical use. (2) To demonstrate the variability that exists across states in rules governing patient access, product safety and dispensary practice. Two legal researchers collected and coded state laws governing marijuana patients, product safety and dispensaries in effect on 1 February 2017, creating three empirical legal data sets. We used summary tables to identify the variation in specific statutory provisions specified in each state's medical marijuana law as it existed on 1 February 2017. We compared aspects of these laws to the traditional Federal approach to regulating medicine. Full data sets, codebooks and protocols are available through the Prescription Drug Abuse Policy System (http://www.pdaps.org/; Archived at http://www.webcitation.org/6qv5CZNaZ on 2 June 2017). Twenty-eight states (including the District of Columbia) have authorized medical marijuana. Twenty-seven specify qualifying diseases, which differ across states. All states protect patient privacy; only 14 protect patients against discrimination. Eighteen states have mandatory product safety testing before any sale. While the majority have package/label regulations, states have a wide range of specific requirements. Most regulate dispensaries (25 states), with considerable variation in specific provisions such as permitted product supply sources number of dispensaries per state and restricting proximity to various types of location. The federal ban in the United States on marijuana has resulted in a patchwork of regulatory strategies that are not uniformly consistent with the approach usually taken by the Federal government and whose effectiveness remains unknown. © 2017 Society for the Study of Addiction.

LLNL medical and industrial laser isotope separation: large volume, low cost production through advanced laser technologies

International Nuclear Information System (INIS)

Comaskey, B.; Scheibner, K. F.; Shaw, M.; Wilder, J.

1998-01-01

The goal of this LDRD project was to demonstrate the technical and economical feasibility of applying laser isotope separation technology to the commercial enrichment (>lkg/y) of stable isotopes. A successful demonstration would well position the laboratory to make a credible case for the creation of an ongoing medical and industrial isotope production and development program at LLNL. Such a program would establish LLNL as a center for advanced medical isotope production, successfully leveraging previous LLNL Research and Development hardware, facilities, and knowledge

Applying Toyota production system techniques for medication delivery: improving hospital safety and efficiency.

Science.gov (United States)

Newell, Terry L; Steinmetz-Malato, Laura L; Van Dyke, Deborah L

2011-01-01

The inpatient medication delivery system used at a large regional acute care hospital in the Midwest had become antiquated and inefficient. The existing 24-hr medication cart-fill exchange process with delivery to the patients' bedside did not always provide ordered medications to the nursing units when they were needed. In 2007 the principles of the Toyota Production System (TPS) were applied to the system. Project objectives were to improve medication safety and reduce the time needed for nurses to retrieve patient medications. A multidisciplinary team was formed that included representatives from nursing, pharmacy, informatics, quality, and various operational support departments. Team members were educated and trained in the tools and techniques of TPS, and then designed and implemented a new pull system benchmarking the TPS Ideal State model. The newly installed process, providing just-in-time medication availability, has measurably improved delivery processes as well as patient safety and satisfaction. Other positive outcomes have included improved nursing satisfaction, reduced nursing wait time for delivered medications, and improved efficiency in the pharmacy. After a successful pilot on two nursing units, the system is being extended to the rest of the hospital. © 2010 National Association for Healthcare Quality.

Development of a Medical Cyclotron Production Facility

Science.gov (United States)

Allen, Danny R.

2003-08-01

Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes.

Development of a Medical Cyclotron Production Facility

International Nuclear Information System (INIS)

Allen, Danny R.

2003-01-01

Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes

Shock loading influence on mechanical behavior of high purity iron

International Nuclear Information System (INIS)

Buy, Francois; Voltz, Christophe

2004-01-01

This paper proposes the analysis of shock wave effects for high purity iron. The method developed is based on the characterization of the mechanical behavior of as received and shocked material. Shock effect is generated through plate impact tests performed in the range of 4 GPa to 39 GPa on a single stage light gas gun or a powder gun. Therefore, as-received and impacted materials are characterized. A formalism proposed by J.R.Klepaczko and based on physical relations has been adopted to describe stress strain curves

Properties of structural steels melted out of high-purity charge

International Nuclear Information System (INIS)

Marchenko, V.N.; Sergeeva, T.K.; Kondakova, N.K.; Morozov, V.P.; Madorskij, L.L.

1993-01-01

A comparative evaluation has been made of impurities, mechanical properties and hydrogen embirittlement parameters for steels type 40Kh and 40KhS produced by electrometallurgical method with the use of direct reduced charge (DR-steels) and melted in an open-hearth furnace. Investigation results have shown that 40Kh and 40KhS Dr-steels have more coarse austenitic grains and experience more complete transformation of martensite into ferritic-pearlitic mixture on tempering. Threshold stresses increase 2.5 times due to purity enhancement at the expense of application of direct reduced charge

The ion-exchange obtaining of high purity samarium oxide

International Nuclear Information System (INIS)

Brzyska, W.; Soltysiak, I.; Cygan, J.

1987-01-01

The use of lactic acid - EDTA mixture as an eluent for the obtaining of high purity samarium oxide was studied. The studies were carried out at room temperature on cation exchange resin Wofatit KPS X 8. The best results were obtained for lactic acid (0,26 mol/dm 3 ) - EDTA (0,013 mol/dm 3 ) mixture at pH 3,3. As the result of 57% samarium concentrate elution with column load 1:3 and flow rate 0,4 cm/min, over 99% pure samarium oxide with 73% yield has been obtained. The yield of spectrally pure Sm 2 O 3 exceeded 45%. (author)

Isolation and purification of G immunoglobulin from guinea-pig for the production of a second antibody for radioimmunoassay

International Nuclear Information System (INIS)

Silva, S.R.; Borghi, V.C.; Bellini, M.H.; Wajchenberg, W.A.J.

1992-01-01

The IgG of guinea-pig was isolated and purified by precipitation with caprylic acid and the batch absorption with DEAE-cellulose. The efficiency of the operating was verified by the determination of total proteins, during the purification stages. The purity of the end product was proved by immuno electrophoresis face to rabbit serum total antiserum of guinea-pig. it was obtained 240 mg of purity IgG to be used in the production of second specific antibody for radioimmunoassay. (C.G.C.)

Trends, productivity losses, and associated medical conditions among toxoplasmosis deaths in the United States, 2000-2010.

Science.gov (United States)

Cummings, Patricia L; Kuo, Tony; Javanbakht, Marjan; Sorvillo, Frank

2014-11-01

Few studies have quantified toxoplasmosis mortality, associated medical conditions, and productivity losses in the United States. We examined national multiple cause of death data and estimated productivity losses caused by toxoplasmosis during 2000-2010. A matched case-control analysis examined associations between comorbid medical conditions and toxoplasmosis deaths. In total, 789 toxoplasmosis deaths were identified during the 11-year study period. Blacks and Hispanics had the highest toxoplasmosis mortality compared with whites. Several medical conditions were associated with toxoplasmosis deaths, including human immunodeficiency virus (HIV), lymphoma, leukemia, and connective tissue disorders. The number of toxoplasmosis deaths with an HIV codiagnosis declined from 2000 to 2010; the numbers without such a codiagnosis remained static. Cumulative disease-related productivity losses for the 11-year period were nearly $815 million. Although toxoplasmosis mortality has declined in the last decade, the infection remains costly and is an important cause of preventable death among non-HIV subgroups. © The American Society of Tropical Medicine and Hygiene.

The effects of vacuum induction melting and electron beam melting techniques on the purity of NiTi shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

Otubo, J. [Instituto Tecnologico de Aeronautica (ITA), 12228-900 S.J. Campos, SP (Brazil) and DEMA-FEM-UNICAMP, 13083-000 Campinas, SP (Brazil)]. E-mail: jotubo@ita.br; Rigo, O.D. [DEMA-FEM-UNICAMP, 13083-000 Campinas, SP (Brazil); Neto, C. Moura [Instituto Tecnologico de Aeronautica (ITA), 12228-900 S.J. Campos, SP (Brazil); Mei, P.R. [DEMA-FEM-UNICAMP, 13083-000 Campinas, SP (Brazil)

2006-11-25

The usual process to produce NiTi shape memory alloys is by vacuum induction melting (VIM) using graphite crucible that contaminates the bath with carbon. The contamination by oxygen comes from residual oxygen inside the melting chamber. A new alternative process to produce NiTi alloys is by electron beam melting (EBM) using water-cooled copper crucible that eliminates the carbon contamination and the oxygen contamination would be minimized due to operation in high vacuum. This work compares the two processes and shows that the carbon contamination is four to ten times lower for EBM compared to VIM products and that the final oxygen content is much more dependent on the starting raw materials. The purity of the final product should be very important mainly in terms of biomedical applications and the contaminations by carbon and oxygen affect the direct and reverse martensitic transformation temperatures.

Neutron activation determination of impurities in high-purity bismuth with separation of matrix in form of hydroxide

International Nuclear Information System (INIS)

Artyukhin, P.I.; Shavinskij, B.M.; Mityakin, Yu.L.

1979-01-01

The technique of neutron activation determination of 15 impurity elements (Au, Ag, Ba, Cd, Co, Cs, Cu, Hg, K, Na, Ni, Se, Sr, Te, Zn) in high-purity bismuth (impurity content is approximately 10 -6 -10 -10 %) is presented. Bismuth hydroxide precipitation by ammonia from nitric acid solutions was used to separate bismuth from alkali, alkaline earth metals and elements forming stable ammines. Gold, selenium and tellurium are isolated in the form of metals at reduction by muriatic hydrazine. Results of analyzing two samples of special purity bismuth are presented. Neutron flux comprised 0.8-1x10 13 n/cm 2 xs. Radiation time was equal to 90 hours

Obtaining water with a high degree of purity by using reverse osmosis

Directory of Open Access Journals (Sweden)

Nicolae Chirilă

2011-12-01

Full Text Available In this paper, we used the method of reverse osmosis in order to obtain water with a high degree of purity. For this aim, we used the TKA 20-120ECO device. We completed physic-chemical determinations for the water of supply, as well as for the water obtained after the osmosis process. The results that we obtained are relevant and interesting.

Production of lipase from Geotrichum sp and adsorption studies on affinity resin

Directory of Open Access Journals (Sweden)

E. S. KAMIMURA

1999-06-01

Full Text Available There is a growing interest in microbial lipase production due to its great potential for industrial applications such as food additives, industrial reagents and stain removers, as well as for medical applications. Specially for medical applications a high degree of purity is required, which is accomplished with high resolution chromatographic techniques. Affinity chromatography is considered a very high resolution chromatographic technique. In this work the adsorption isotherms and kinetics of the adsorption of lipase from Geotrichum sp on biospecific resin were determined. The resin was prepared using EAH sepharose 4B gel (Pharmacia, made to react with oleic acid as the specific ligand.The lipase was produced in a five-liter fermenter, with both complex and synthetic media. Fermentation conditions were a temperature of 30°C, an aeration of 1VVM and an agitation of 400 rpm. Maximum lipase activity was around 28 U/ml after 10 hours of fermentation for the complex medium. The kinetic model and parameters were determined by dynamic fitting to experimental results using the fourth-order Runge-Kutta method.

Estudio del grado de pureza de la nitrofurazona obtenida a partir de un derivado de la industria cañera cubana Study of the purity degree of Nitrofurazone obtained from a Cuban sugar cane industry byproduct

Directory of Open Access Journals (Sweden)

Adolfo L Brown Gómez

2006-04-01

Full Text Available Se estudió el grado de pureza a diferentes lotes de nitrofurazona sintetizados en el Instituto Cubano de Investigaciones de Derivados de la Caña de Azúcar (ICIDCA mediante la combinación de 3 técnicas analíticas: la cromatografía de placa delgada, la cromatografía líquida de alta resolución y la calorimetría diferencial de barrido. Se obtuvieron resultados satisfactorios que permiten evaluar la calidad de los productos y compararlos con productos competitivos a escala comercial con purezas entre el 98 y 100 %The purity degree of different Nitrofurazone batches synthetized in ICIDCA was studied using combination of three analytical techniques: the Thin Layer Chromatography (TLC, High Performance Liquid Chromatography (HPLC and Differential Scanning Calorimetry (DSC. Positive results were obtained that permit to evaluate quality of products and to compare them with competitive products at a market scale with 98 and 100 % purity degree

Emerging Use of Early Health Technology Assessment in Medical Product Development: A Scoping Review of the Literature.

Science.gov (United States)

IJzerman, Maarten J; Koffijberg, Hendrik; Fenwick, Elisabeth; Krahn, Murray

2017-07-01

Early health technology assessment is increasingly being used to support health economic evidence development during early stages of clinical research. Such early models can be used to inform research and development about the design and management of new medical technologies to mitigate the risks, perceived by industry and the public sector, associated with market access and reimbursement. Over the past 25 years it has been suggested that health economic evaluation in the early stages may benefit the development and diffusion of medical products. Early health technology assessment has been suggested in the context of iterative economic evaluation alongside phase I and II clinical research to inform clinical trial design, market access, and pricing. In addition, performing early health technology assessment was also proposed at an even earlier stage for managing technology portfolios. This scoping review suggests a generally accepted definition of early health technology assessment to be "all methods used to inform industry and other stakeholders about the potential value of new medical products in development, including methods to quantify and manage uncertainty". The present review also aimed to identify recent published empirical studies employing an early-stage assessment of a medical product. With most included studies carried out to support a market launch, the dominant methodology was early health economic modeling. Further methodological development is required, in particular, by combining systems engineering and health economics to manage uncertainty in medical product portfolios.

Analysis of the radiochemical purity of 18F-FDG by HPLC

International Nuclear Information System (INIS)

Chen Liguang; Tang Anwu; He Shanzhen; Chen Yulong

2001-01-01

The radiochemical purity (RCP) of 18 F-FDG is analyzed by HPLC. Eighty-five percent acetonitrile is used as the eluting solution. Carbon hydrate column is used as separation column. The t R of 18 F - is 6.50 min and 18 F-FDG is 9.00 min. HPLC take less time and has higher sensitivity than TLC for the same sample at the same time. So HPLC excels TLC in analyzing RCP of 18 F-FDG

Dedication increases productivity: an analysis of the implementation of a dedicated medical team in the emergency department.

Science.gov (United States)

Ramos, Pedro; Paiva, José Artur

2017-12-01

In several European countries, emergency departments (EDs) now employ a dedicated team of full-time emergency medicine (EM) physicians, with a distinct leadership and bed-side emergency training, in all similar to other hospital departments. In Portugal, however, there are still two very different models for staffing EDs: a classic model, where EDs are mostly staffed with young inexperienced physicians from different medical departments who take turns in the ED in 12-h shifts and a dedicated model, recently implemented in some hospitals, where the ED is staffed by a team of doctors with specific medical competencies in emergency medicine that work full-time in the ED. Our study assesses the effect of an intervention in a large academic hospital ED in Portugal in 2002, and it is the first to test the hypothesis that implementing a dedicated team of doctors with EM expertise increases the productivity and reduces costs in the ED, maintaining the quality of care provided to patients. A pre-post design was used for comparing the change on the organisational model of delivering care in our medical ED. All emergency medical admissions were tracked in 2002 (classic model with 12-h shift in the ED) and 2005/2006 (dedicated team with full-time EM physicians), and productivity, costs with medical human resources and quality of care measures were compared. We found that medical productivity (number of patients treated per hour of medical work) increased dramatically after the creation of the dedicated team (X 2 KW = 31.135; N = 36; p work reduced both in regular hours and overtime. Moreover, hospitalisation rates decreased and the length of stay in the ED increased significantly after the creation of the dedicated team. Implementing a dedicated team of doctors increased the medical productivity and reduced costs in our ED. Our findings have straightforward implication for Portuguese policymakers aiming at reducing hospital costs while coping with increased ED demand.

Summary report of the consultants' meeting on nuclear data for production of therapeutic radioisotopes

International Nuclear Information System (INIS)

Haight, R.C.; Paviotti-Corcuera, R.

2002-04-01

This report summarizes the presentations, recommendations and conclusions of the Consultants' Meeting on Nuclear Data for Production of Therapeutic Radioisotopes. The purpose of this meeting was to discuss scientific and technical matters related to the subject and to advise the IAEA Nuclear Data Section (NDS) on the need and possible formation of a Coordinated Research Programme (CRP). Accurate and complete knowledge of nuclear data are essential for the production of radionuclides for therapy to achieve the specific activity and purity required for efficient and safe clinical application. The Consultants recommended updating and completing the data for production of radionuclides that are recognized to be important in therapy. In addition, the consultants recommend investigating other radionuclides that have a potential interest and for which there exists a medical rationale for therapeutic use. To date no serious effort has been devoted to evaluation of nuclear data for the reactor and accelerator production of therapeutic radionuclides. The IAEA is in the unique and privileged position to address this important public health related problem. Therefore, the consultants highly recommend the formation of a CRP with the title: 'Nuclear Data for Production of Therapeutic Radionuclides.' (author)

Spontaneously Reported Adverse Reactions for Herbal Medicinal Products and Natural Remedies in Sweden 2007-15: Report from the Medical Products Agency.

Science.gov (United States)

Svedlund, Erika; Larsson, Maria; Hägerkvist, Robert

2017-06-01

In relation to the extensive use of herbal medicinal products in self-care, the safety information is limited and there is a need for improvement. This study describes spontaneously reported adverse reactions related to herbal medicinal products and natural remedies in Sweden. To evaluate the characteristics and frequency of adverse events recorded by the Swedish Medical Products Agency, where herbal medicinal products and natural remedies were suspected as causative agents. Adverse drug reactions reported to the Swedish Medical Product Agency during 2007-15 related to approved herbal medicinal products or natural remedies were included and analysed in the retrospective study. Reports had been assessed for causality when they were lodged and only reports that had been assessed as at least possible were included in the study. In total, 116 reports (concerning 259 adverse reactions) related to herbal medicinal products or natural remedies were found in the Swedish national pharmacovigilance database. The active ingredients most frequently suspected during the study period were black cohosh rhizome (15 reports), purple coneflower herb (14 reports) and a combination of extracts of pollen (13 reports). Adverse reactions related to skin and subcutaneous tissue were the most commonly reported reactions. No previously unknown safety problems have been discovered in the present study. This finding could be explained by a thorough pre-approval assessment of medicinal products and the fact that most herbal preparations in medicinal products have been in clinical use for many years (for traditional herbal medicinal products, the requirements are ≥30 years), i.e. adverse reactions are acknowledged and assessed before approval.

A novel FPGA-based bunch purity monitor system at the APS storage ring

International Nuclear Information System (INIS)

Norum, W.E.

2008-01-01

Bunch purity is an important source quality factor for the magnetic resonance experiments at the Advanced Photon Source. Conventional bunch-purity monitors utilizing time-to-amplitude converters are subject to dead time. We present a novel design based on a single field- programmable gate array (FPGA) that continuously processes pulses at the full speed of the detector and front-end electronics. The FPGA provides 7778 single-channel analyzers (six per rf bucket). The starting time and width of each single-channel analyzer window can be set to a resolution of 178 ps. A detector pulse arriving inside the window of a single-channel analyzer is recorded in an associated 32-bit counter. The analyzer makes no contribution to the system dead time. Two channels for each rf bucket count pulses originating from the electrons in the bucket. The other four channels on the early and late side of the bucket provide estimates of the background. A single-chip microcontroller attached to the FPGA acts as an EPICS IOC to make the information in the FPGA available to the EPICS clients.

Dispersion-strengthened aluminium powder products for nuclear application

DEFF Research Database (Denmark)

Hansen, Niels

1967-01-01

Strength, elongation, corrosion resistance, homogeneity, purity, compatibility with fuel, and resistance to irradiation damage, being main properties of SAP of interest for their application in nuclear technology, are discussed in connection with commercial products; effect on tensile and creep...

Production of stable isotopes utilizing the plasma separation process

Science.gov (United States)

Bigelow, T. S.; Tarallo, F. J.; Stevenson, N. R.

2005-12-01

A plasma separation process (PSP) is being operated at Theragenics Corporation's®, Oak Ridge, TN, facility for the enrichment of stable isotopes. The PSP utilizes ion cyclotron mass discrimination to separate isotopes on a relatively large scale. With a few exceptions, nearly any metallic element could be processed with PSP. Output isotope enrichment factor depends on natural abundance and mass separation and can be fairly high in some cases. The Theragenics™ PSP facility is believed to be the only such process currently in operation. This system was developed and formerly operated under the US Department of Energy Advanced Isotope Separation program. Theragenics™ also has a laboratory at the PSP site capable of harvesting the isotopes from the process and a mass spectrometer system for analyzing enrichment and product purity. Since becoming operational in 2002, Theragenics™ has utilized the PSP to separate isotopes of several elements including: dysprosium, erbium, gadolinium, molybdenum and nickel. Currently, Theragenics™ is using the PSP for the separation of 102Pd, which is used as precursor for the production of 103Pd. The 103Pd radioisotope is the active ingredient in TheraSeed®, which is used in the treatment of early stage prostate cancer and being investigated for other medical applications. New industrial, medical and research applications are being investigated for isotopes that can be enriched on the PSP. Pre-enrichment of accelerator or reactor targets offers improved radioisotope production. Theragenics operates 14 cyclotrons for proton activation and has access to HFIR at ORNL for neutron activation of radioisotopes.

Homochiral Acyl Isocyanates as Diagnostic NMR Probes for the Enantiomeric Purity of Chiral Alcohols

Directory of Open Access Journals (Sweden)

Gregory H. P. Roos

2000-12-01

Full Text Available The first reported acyl and sulfonylisocyanates were developed and tested in reactions with chiral alcohols to afford diastereomeric carbamates. NMR analysis of these investigates the chemical shift discrimination that would allow these activated isocyanates to be used as diagnostic probes of enantiomeric purity.

On-line sodium and cover as purity monitors gas operating tools at EBR-II

International Nuclear Information System (INIS)

Smith, C.R.F.; Richardson, W.J.; Holmes, J.T.

1976-01-01

Plugging temperature indicators, electrochemical oxygen meters and hydrogen diffusion meters are the on-line sodium purity monitors now in use at EBR-II. On-line gas chromatographs are used to monitor helium, hydrogen, oxygen and nitrogen impurities in the argon cover gases. Monitors for tritium-in-sodium and for hydrocarbons-in-cover gas have been developed and are scheduled for installation in the near future. An important advantage of on-line monitors over the conventional grab-sampling techniques is the speed of response to changing reactor conditions. This helps us to identify the source of the impurity, whether the cause may be transient or constant, and take corrective action as necessary. The oxygen meter is calibrated monthly against oxygen in sodium determined by the vanadium wire equilibration method. The other instruments either do not require calibration or are self-calibrating. The ranges, sensitivity and response times of all of the on-line purity monitors has proven satisfactory under EBR-II operating conditions

Effect of initial grain size on dynamic recrystallization in high purity austenitic stainless steels

International Nuclear Information System (INIS)

El Wahabi, M.; Gavard, L.; Montheillet, F.; Cabrera, J.M.; Prado, J.M.

2005-01-01

The influence of initial microstructure on discontinuous dynamic recrystallization (DDRX) has been investigated by using high purity and ultra high purity austenitic stainless steels with various initial grain sizes. After uniaxial compression tests at constant strain rates and various temperatures, the steady state microstructure or the state corresponding to the maximum strain (ε = 1) attained in the test was analyzed by scanning electron microscopy aided with automated electron back scattering diffraction. Recrystallized grain size d rec and twin boundary fraction f TB measurements were carried out. The mechanical behavior was also investigated by comparing experimental stress-strain curves with various initial grain sizes. DDRX kinetics was described by the classical Avrami equation. It was concluded that larger initial grain sizes promoted a delay in the DDRX onset in the two alloys. It was also observed that the softening process progressed faster for smaller initial grain sizes. The effect of initial grain size is larger in the HP material and becomes more pronounced at low temperature

Phase transformations of high-purity PbI{sub 2} nanoparticles synthesized from lead-acid accumulator anodes

Energy Technology Data Exchange (ETDEWEB)

Malevu, T.D., E-mail: malevutd@ufs.ac.za; Ocaya, R.O.; Tshabalala, K.G.

2016-09-01

High-purity hexagonal lead iodide nanoparticles have been synthesized from a depleted sealed lead acid battery anode. The synthesized product was found to consist of the rare 6R polytype form of PbI{sub 2} that is thought to have good potential in photovoltaic applications. We investigate the effects of annealing time and post-melting temperature on the structure and optical properties using 1.5418 Å CuKα radiation. Photoluminescence measurements were done under 150 W/221 nm wavelength xenon excitation. Phase transformation was observed through XRD peaks when annealing time increased from 0.5–5 h. The nanoparticle grain size and inter-planar distance appeared to be independent of annealing time. PL measurements show three broad peaks in a range of 400 nm to 700 nm that are attributed to excitonic, donor–acceptor pair and luminescence bands from the deep levels.

Medical radioisotopes production at the isochronous cyclotron in Alma-Ata

International Nuclear Information System (INIS)

Arzumanov, A.A.; Batischev, V.N.; Gladun, V.K.; Kochetkov, V.L.

1988-01-01

High efficiency cyclotron operations (up to 5200 hours of beam time a year) considerably increased the possibility to perform both fundamental and applied scientific work. There appeared possibility to accelerate protons in a wide energy range from 6 to 30 MeV and realize correspondingly the nuclear reactions up to (A, 3n). This paper reports that among different applied tasks performed at the cyclotron the special program of cyclotron production of short-lived medical radioisotopes iodine-123, thallium-201, cadmium-109 in the first place and some others to satisfy clinic needs of Alma-Ata and its region has special importance. In accordance with this program the preparation to produce iodine-123 is being held and regular production of Thallium chloride, thallium-201 pharmaceptical is started

Datenschutz- und Medizinprodukterecht bei Ubiquitous Computing-Anwendungen im Gesundheitssektor / Data protection and medical product law with respect to medical ubiquitous computing applications

Directory of Open Access Journals (Sweden)

Skistims, Hendrik

2011-01-01

Full Text Available With respect to ubiquitous computing there is a great potential of application, particularly in medicine and health care. This work deals with the legal problems which ubiquitous computing is facing in these areas. At the beginning, issues with respect to data protection and professional secrecy are treated. Afterwards the problem of applicability of medical product law for medical ubiquitous computing applications as well as the resulting requirements for manufactures, operators and users will be discussed.

Influence of Genetic Drift of Restoring Gene (Rf on Seed Purity of Yuetai A, a Honglian-Type Cytoplasmic Male Sterile Line in Hybrid Rice

Directory of Open Access Journals (Sweden)

Ji-feng Wang

2008-06-01

Full Text Available The seed samples of Yuetai A, a Honglian (HL type cytoplasmic male sterile (CMS line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biological contaminant to Yuetai A in Nanjing, Jiangsu Province and Lingshui, Hainan Province during 2004–2006. The seed impurity of Yuetai A mainly resulted from the genetic drift of restoring fertility gene (Rf after biological contamination but not from its sterility unstability. All of the ten maintainer lines, five restorer lines and three thermo-sensitive genic male sterile lines used in the study could pollinate Yuetai A and Yuetai B to produce F1 plants, directly or indirectly resulting in Rf-gene drifting into Yuetai A and generating ‘iso-cytoplasm restoring-generations’. Furthermore, high outcrossing rate and similar heading date of Yuetai A with many varieties used in rice production might easily result in the biological contamination. After removing all plants with Rf-gene mixed in Yuetai A and preventing Rf-gene drifting into Yuetai A, the seed purity of Yuetai A and Yuetai B had been raised to 100%.

A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials.

Science.gov (United States)

Soinila, E; Pihlajamäki, T; Bossuyt, S; Hänninen, H

2011-07-01

An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr(55)Cu(30)Al(10)Ni(5) directly into rods up to ø 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.

Charge collection performance of a segmented planar high-purity germanium detector

Energy Technology Data Exchange (ETDEWEB)

Cooper, R.J. [Department of Physics, The University of Liverpool, Oliver Lodge Laboratory, Liverpool Merseyside L69 7ZE (United Kingdom)], E-mail: R.Cooper@liverpool.ac.uk; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Grint, A.N.; Harkness, L.J.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P. [Department of Physics, The University of Liverpool, Oliver Lodge Laboratory, Liverpool Merseyside L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Warrington, Cheshire WA4 4AD (United Kingdom); Dobson, J. [Rosemere Cancer Centre, Royal Preston Hospital, Preston PR2 9HT (United Kingdom)

2008-10-01

High-precision scans of a segmented planar high-purity germanium (HPGe) detector have been performed with a range of finely collimated gamma ray beams allowing the response as a function of gamma ray interaction position to be quantified. This has allowed the development of parametric pulse shape analysis (PSA) techniques and algorithms for the correction of imperfections in performance. In this paper we report on the performance of this detector, designed for use in a positron emission tomography (PET) development system.

Design, construction, and operation of a laboratory scale reactorfor the production of high-purity, isotopically enriched bulksilicon

Energy Technology Data Exchange (ETDEWEB)

Ager III, J.W.; Beeman, J.W.; Hansen, W.L.; Haller, E.E.

2004-12-20

The design and operation of a recirculating flow reactor designed to convert isotopically enriched silane to polycrystalline Si with high efficiency and chemical purity is described. The starting material is SiF{sub 4}, which is enriched in the desired isotope by a centrifuge method and subsequently converted to silane. In the reactor, the silane is decomposed to silicon on the surface of a graphite starter rod (3 mm diameter) heated to 700-750 C. Flow and gas composition (0.3-0.5% silane in hydrogen) are chosen to minimize the generation of particles by homogeneous nucleation of silane and to attain uniform deposition along the length of the rod. Growth rates are 5 {micro}m/min, and the conversion efficiency is greater than 95%. A typical run produces 35 gm of polycrystalline Si deposited along a 150 mm length of the rod. After removal of the starter rod, dislocation-free single crystals are formed by the floating zone method. Crystals enriched in all 3 stable isotopes of Si have been made: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (88.25%). Concentrations of electrically active impurities (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup 15} cm{sup -3}, respectively.

Hot flow of a commercial-purity copper

International Nuclear Information System (INIS)

Garcia, V. G.; El Wahabi, M.; Cabrera, J. M.; Riera, L. M.; Prado, J. M.

2001-01-01

The objective of the study is to model the flow curve at high temperature of a commercial-purity copper which contains 297 ppm of phosphorus. For this purpose a theoretical model is applied to derive a constitutive equation that reliably predicts the behaviour at higher strain rates than experimentally tested. The test temperature range was from 873 K to 1223 K in increments of 50 K, using six true strain rates at every temperature, which span from 0.3 s''-1 to 0.001 s''-1. The hot flow tests were performed on a copper with a relatively large grain size (637 μm) but of similar scale to pertinent industrial processes. This metal presents two antagonistic phenomena during the hot working: strain hardening and softening by dynamic restoration, which in turns can be divided into dynamic recovery and dynamic recrystallization. A quantification of the mentioned mechanisms is done through the use of physically based constitutive equations. (Author) 20 refs

Radioactive isotope production for medical applications using Kharkov electron driven subcritical assembly facility

International Nuclear Information System (INIS)

Talamo, A.; Gohar, Y.

2007-01-01

Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics experiments and material research will be carried out using the capabilities of this facility. The United States of America and Ukraine have started collaboration activity for developing a conceptual design for this facility with low enrichment uranium (LEU) fuel. Different conceptual designs are being developed based on the facility mission and the engineering requirements including nuclear physics, neutronics, heat transfer, thermal hydraulics, structure, and material issues. Different fuel designs with LEU and reflector materials are considered in the design process. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements and upgrades. This report is a part of the Argonne National Laboratory Activity within this collaboration for developing and characterizing the subcritical assembly conceptual design. In this study, the medical isotope production function of the Kharkov facility is defined. First, a review was carried out to identify the medical isotopes and its medical use. Then a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Finally, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and irradiation location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes were considered and all transmutation channels are used including (n,γ), (n,2n), (n,p), and (γ,n). In the second part, the parent

Radioactive isotope production for medical applications using Kharkov electron driven subcritical assembly facility.

Energy Technology Data Exchange (ETDEWEB)

Talamo, A.; Gohar, Y.; Nuclear Engineering Division

2007-05-15

Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics experiments and material research will be carried out using the capabilities of this facility. The United States of America and Ukraine have started collaboration activity for developing a conceptual design for this facility with low enrichment uranium (LEU) fuel. Different conceptual designs are being developed based on the facility mission and the engineering requirements including nuclear physics, neutronics, heat transfer, thermal hydraulics, structure, and material issues. Different fuel designs with LEU and reflector materials are considered in the design process. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements and upgrades. This report is a part of the Argonne National Laboratory Activity within this collaboration for developing and characterizing the subcritical assembly conceptual design. In this study, the medical isotope production function of the Kharkov facility is defined. First, a review was carried out to identify the medical isotopes and its medical use. Then a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Finally, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and irradiation location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes were considered and all transmutation channels are used including (n,{gamma}), (n,2n), (n,p), and ({gamma},n). In the second part

Medical Isotopes Production Project: Molybdenum-99 and related isotopes - environmental impact statement. Volume II, comment response document

International Nuclear Information System (INIS)

1996-04-01

This Environmental Impact Statement (EIS) provides environmental and technical information concerning the U.S. Department of Energy's (DOE) proposal to establish a domestic source to produce molybdenum-99 (Mo-99) and related isotopes (iodine-131, xenon-133, and iodine-125). Mo-99, a radioactive isotope of the element molybdenum, decays to form metastable technetium-99 (Tc-99m), a radioactive isotope used thousands of times daily in medical diagnostic procedures in the U.S. Currently, all Mo-99 used in the U.S. is obtained from a single Canadian source. DOE is pursuing the Medical Isotopes Production Project in order to ensure that a reliable supply of Mo-99 is available to the U.S. medical community as soon as practicable. Under DOE's preferred alternative, the Chemistry and Metallurgy Research Facility at the Los Alamos National Laboratory (LANL) and the Annular Core Research Reactor and Hot Cell Facility at Sandia National Laboratories/New Mexico (SNL/NM) would be used for production of the medical isotopes. In addition, three other reasonable alternatives and a No Action alternative are analyzed in detail, The sites for these three reasonable alternatives are LANL, Oak Ridge National Laboratory (ORNL), and Idaho National Engineering Laboratory (INEL). The analyses in this EIS indicate no significant difference in the potential environmental impacts among the alternatives. Each of the alternatives would use essentially the same technology for the production of the medical isotopes. Minor differences in environmental impacts among alternatives relate to the extent of activity necessary to modify and restart (as necessary) existing reactors and hot cell facilities at each of the sites, the quantities of low-level radioactive waste generated, how such waste would be managed, and the length of time needed for initial and full production capacity. This document contains comments recieved from meetings held regarding the site selection for isotope production

The commercial production of compounds of the lanthanides and yttrium as CRT phosphor precursors

International Nuclear Information System (INIS)

Kilbourn, B.T.

1987-01-01

The consumer acceptance of color television at the start of the 60's was triggered by the phosphor industry's discovery and production of a satisfactory red phosphor using the element europium. This element, in the middle of the lanthanide series, had until that time been an academic curiosity, prepared only in gram quantities for research. The large-scale production by the lanthanide industry, in order to meet the demand for commercial quantities of high purity europium oxide, required the introduction of new technology. Lanthanide elements other than europium, such as cerium and terbium, are also needed as the active ions for many phosphors. In addition, the inert host lattice for those emitting ions can be provided by compounds of yttrium, the element above the lanthanides in the periodic table, with comparable properties. The lanthanide industry has developed processes to produce compounds of such elements in the required quantities and purities. For commercial separation of these elements a technology known as counter-current liquid-liquid extraction has been developed. This technique, commonly called solvent extraction, is illustrated and described. The initial ore preparation steps, together with the final high purity oxide production is also mentioned

Germanium recovery from gasification fly ash: evaluation of end-products obtained by precipitation methods.

Science.gov (United States)

Arroyo, Fátima; Font, Oriol; Fernández-Pereira, Constantino; Querol, Xavier; Juan, Roberto; Ruiz, Carmen; Coca, Pilar

2009-08-15

In this study the purity of the germanium end-products obtained by two different precipitation methods carried out on germanium-bearing solutions was evaluated as a last step of a hydrometallurgy process for the recovery of this valuable element from the Puertollano Integrated Gasification Combined Cycle (IGCC) fly ash. Since H(2)S is produced as a by-product in the gas cleaning system of the Puertollano IGCC plant, precipitation of germanium as GeS(2) was tested by sulfiding the Ge-bearing solutions. The technological and hazardous issues that surround H(2)S handling conducted to investigate a novel precipitation procedure: precipitation as an organic complex by adding 1,2-dihydroxy benzene pyrocatechol (CAT) and cetyltrimethylammonium bromide (CTAB) to the Ge-bearing solutions. Relatively high purity Ge end-products (90 and 93% hexagonal-GeO(2) purity, respectively) were obtained by precipitating Ge from enriched solutions, as GeS(2) sulfiding the solutions with H(2)S, or as organic complex with CAT/CTAB mixtures and subsequent roasting of the precipitates. Both methods showed high efficiency (>99%) to precipitate selectively Ge using a single precipitation stage from germanium-bearing solutions.

Purity determination of 60Co gamma irradiated atropine sulphate by different analytical techniques (Preprint No. RA.05)

International Nuclear Information System (INIS)

Balan, N.; Sharma, G.; Gopal, N.G.S.

1989-01-01

Some of the results obtained, employing high performance liquid chromatography (HPLC) are reported and some other methods to determine the purit y of radiation sterilized atropine sulphate in solid (I) and in aqueous solutions (0.1 per cent to 1.0 per cent w/v) (II) are also described. (I) and (II) were irradiated to graded doses of 10-100kGy and 5-20kGy respectively. The purity of irradiated sample (I) vis-a-vis unirradiated was determined using non aqueous potentiometric titration, thin layer chromatography, uv-vis spectrophotometry, HPLC and differential scanning calorimetry (DSC). Purity of (II) was examined only by HPLC vis-a-vis unirradiated aqueous solution. (author). 3 figs

Pilot material handling system for radiation processing of agricultural and medical products

International Nuclear Information System (INIS)

Sandha, R.S.; Nageswar Rao, J; Dwivedi, Jishnu; Petwal, V.C.; Soni, H.C.

2005-01-01

A 10 MeV, 10 kW electron LINAC based radiation processing facility is being constructed at Centre for Advanced Technology, Indore for radiation processing of various food products like potatoes, onion, spices, home pack items and medical sterilization. A pilot material handling system has been designed, manufactured, and installed at CAT to verify process parameters viz. conveying speed, dose uniformity, and to study the effect of packing shape and size for radiation processing of different product. This paper describes various features of pilot material handling system. (author)

Production of technetium-99m in the Institute of Nuclear Physics of the National Nuclear Center of the Republic of Kazakhstan

International Nuclear Information System (INIS)

Chakrov, P.V.; Bannykh, V.I.; Chakrova, E.T.; Tamaeva, K.; Zhotabaev, Zh.R.

2002-01-01

Institute of Nuclear Physics NNC RK, Almaty, Kazakhstan 'National Nuclear Center, Kurchatov, Kazakhstan In order to organize local production of Technetium-99m radiopharmaceutical in Kazakhstan, research, development and technological work has been carried out at the Laboratory of Radiochemistry, Institute of Nuclear Physics NNC RK, in the period of 1999-2001. The technology developed is based on the so-called 'gel method', which allows to use activated natural molybdenum for production of pertechnetate solution with high radioactive concentration. Along with development of chemical process and design of central Tc-generator, a significant attention was paid to installation of quality control techniques. Complex quality control of technetium eluate from the central gel-type generator was performed, including determination of radionuclidic purity, radiochemical purity, chemical composition, content of elemental impurities, sterility, etc. It was found that pertechnetate produced meets the requirements of Russian and European Pharmacopoeias. High quality of radiopharmaceutical was confirmed subsequently in both pre-clinical and clinical tests performed by three medical centers in Almaty. 72 diagnostic examinations of patients with various diagnoses have been carried out during clinical tests. The radiopharmaceutical S odium pertechnetate solution, Tc-99m produced in the Institute of Nuclear Physics NNC RK is officially registered and permitted for use in Kazakhstan, and its regular supply to Almaty clinics has been started in the year 2002

Scoping assessment on medical isotope production at the Fast Flux Test Facility

International Nuclear Information System (INIS)

Scott, S.W.

1997-01-01

The Scoping Assessment addresses the need for medical isotope production and the capability of the Fast Flux Test Facility to provide such isotopes. Included in the discussion are types of isotopes used in radiopharmaceuticals, which types of cancers are targets, and in what way isotopes provide treatment and/or pain relief for patients

Scoping assessment on medical isotope production at the Fast Flux Test Facility

Energy Technology Data Exchange (ETDEWEB)

Scott, S.W.

1997-08-29

The Scoping Assessment addresses the need for medical isotope production and the capability of the Fast Flux Test Facility to provide such isotopes. Included in the discussion are types of isotopes used in radiopharmaceuticals, which types of cancers are targets, and in what way isotopes provide treatment and/or pain relief for patients.

Fabrication and research of high purity germanium detectors with abrupt and thin diffusion layer

International Nuclear Information System (INIS)

Rodriguez Cabal, A. E.; Diaz Garcia, A.

1997-01-01

A different high purity germanium detector's fabrication method is described. A very thin diffusion film with an abrupt change of the type of conductivity is obtained. The fine diffusion layer thickness makes possibly their utilization in experimental systems in which all the data are elaborated directly on the computer. (author) [es

[Precautions of physical performance requirements and test methods during product standard drafting process of medical devices].

Science.gov (United States)

Song, Jin-Zi; Wan, Min; Xu, Hui; Yao, Xiu-Jun; Zhang, Bo; Wang, Jin-Hong

2009-09-01

The major idea of this article is to discuss standardization and normalization for the product standard of medical devices. Analyze the problem related to the physical performance requirements and test methods during product standard drafting process and make corresponding suggestions.

Low-temperature internal friction in high-purity monocrystalline and impure polycrystalline niobium after plastic deformation

International Nuclear Information System (INIS)

Wasserbaech, W.; Thompson, E.

2001-01-01

The internal friction Q -1 of plastically deformed, high-purity monocrystalline and impure polycrystalline niobium specimens was measured in the temperature range between 65 mK and about 2 K. Plastic deformation has a pronounced effect on the internal friction Q -1 of the high-purity monocrystalline specimens, and the effect has been found to be almost temperature independent. By contrast, surprisingly, the internal friction Q -1 of the impure polycrystalline specimens was found to be almost independent of the extent of plastic deformation. Comparison of the experimental results with different models of a dynamic scattering of acoustic phonons by dislocations leads to the conclusion that the results cannot be explained with the two-level tunneling model. Instead it is suggested that a strong interaction between acoustic phonons and geometrical kinks in non-screw dislocations is responsible for the observed internal friction Q -1 . (orig.)

Neutronic and thermal-hydraulic studies of aqueous homogeneous reactor for medical isotopes production

International Nuclear Information System (INIS)

Perez, Daniel Milian; Lorenzo, Daniel E. Milian; Lira, Carlos A. Brayner de Oliveira; Garcia, Lorena P. Rodríguez; Universidade Federal de Pernambuco

2017-01-01

The use of Aqueous Homogenous Reactors (AHR) is one of the most promissory alternatives to produce medical isotopes, mainly "9"9Mo. Compare to multipurpose research reactors, an AHR dedicated for "9"9Mo production has advantages because of their low cost, small critical mass, inherent passive safety, and simplified fuel handling, processing, and purification characteristics. This article presents the current state of research in our working group on this topic. Are presented and discussed the group validation efforts with benchmarking exercises that include neutronic and thermal-hydraulic results of two solution reactors, the SUPO and ARGUS reactors. Neutronic and thermal-hydraulic results of 75 kWth AHR based on the ARGUS reactor LEU configuration are presented. The neutronic studies included the determination of parameters such as reflector thickness, critical height, medical isotopes production and others. Thermal-hydraulics studies were focused on demonstrating that sufficient cooling capacity exists to prevent fuel overheating. In addition, the effects of some calculation parameters on the computational modeling of temperature, velocity and gas volume fraction during steady-state operation of an AHR are discussed. The neutronic and thermal-hydraulics studies have been performed with the MCNPX version 2.6e computational code and the version 14 of ANSYS CFX respectively. Our group studies and the results obtained contribute to demonstrate the feasibility of using AHR for the production of medical isotopes, however additional studies are still necessary to confirm these results and contribute to development and demonstration of their technical, safety, and economic viability. (author)

Neutronic and thermal-hydraulic studies of aqueous homogeneous reactor for medical isotopes production

Energy Technology Data Exchange (ETDEWEB)

Perez, Daniel Milian; Lorenzo, Daniel E. Milian; Lira, Carlos A. Brayner de Oliveira; Garcia, Lorena P. Rodríguez, E-mail: milianperez89@gmail.com, E-mail: dmilian@instec.cu, E-mail: lorenapilar1109@gmail.com, E-mail: cabol@ufpe.br [Higher Institute of Technologies and Applied Sciences (InSTEC), Havana (Cuba); Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

2017-11-01

The use of Aqueous Homogenous Reactors (AHR) is one of the most promissory alternatives to produce medical isotopes, mainly {sup 99}Mo. Compare to multipurpose research reactors, an AHR dedicated for {sup 99}Mo production has advantages because of their low cost, small critical mass, inherent passive safety, and simplified fuel handling, processing, and purification characteristics. This article presents the current state of research in our working group on this topic. Are presented and discussed the group validation efforts with benchmarking exercises that include neutronic and thermal-hydraulic results of two solution reactors, the SUPO and ARGUS reactors. Neutronic and thermal-hydraulic results of 75 kWth AHR based on the ARGUS reactor LEU configuration are presented. The neutronic studies included the determination of parameters such as reflector thickness, critical height, medical isotopes production and others. Thermal-hydraulics studies were focused on demonstrating that sufficient cooling capacity exists to prevent fuel overheating. In addition, the effects of some calculation parameters on the computational modeling of temperature, velocity and gas volume fraction during steady-state operation of an AHR are discussed. The neutronic and thermal-hydraulics studies have been performed with the MCNPX version 2.6e computational code and the version 14 of ANSYS CFX respectively. Our group studies and the results obtained contribute to demonstrate the feasibility of using AHR for the production of medical isotopes, however additional studies are still necessary to confirm these results and contribute to development and demonstration of their technical, safety, and economic viability. (author)

Martensite. gamma. -->. cap alpha. transformations in various purity Fe-Ni-Mo alloys

Energy Technology Data Exchange (ETDEWEB)

Nikitina, I.I.; Rozhkova, A.S. (Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR))

1982-06-01

Kinetics of isothermal and athermal ..gamma.. ..-->.. ..cap alpha.. martensitic transitions in the Fe-25.5% Ni-4.5% Mo alloys with different degree of purity is studied. The determinant role of dislocation blocking by interstitials in stabilization of isothermal martensitic transformation is displayed. Presented are the data permitting to consider that the character of martensitic transition kinetics is determined by the ratio of the process moving force and resistance to microplastic deformation.

Use of LEU in the aqueous homogeneous medical isotope production reactor

Energy Technology Data Exchange (ETDEWEB)

Ball, R.M. [Babock & Wilcox, Lynchburg, VA (United States)

1997-08-01

The Medical Isotope Production Reactor (MIPR) is an aqueous solution of uranyl nitrate in water, contained in an aluminum cylinder immersed in a large pool of water which can provide both shielding and a medium for heat exchange. The control rods are inserted at the top through re-entrant thimbles. Provision is made to remove radiolytic gases and recombine emitted hydrogen and oxygen. Small quantities of the solution can be continuously extracted and replaced after passing through selective ion exchange columns, which are used to extract the desired products (fission products), e.g. molybdenum-99. This reactor type is known for its large negative temperature coefficient, the small amount of fuel required for criticality, and the ease of control. Calculation using TWODANT show that a 20% U-235 enriched system, water reflected can be critical with 73 liters of solution.

Use of LEU in the aqueous homogeneous medical isotope production reactor