Radiochemical guidelines and process specifications for reactor shutdown: the EDF strategy

International Nuclear Information System (INIS)

Mole, D.; Wintergerst, M.; Meylogan, Th.; Rocher, A.; Sagot, M.J.; Bonelli, V.; Bonnefon, J.; Dupont, B.

2012-09-01

Changes to French nuclear regulations made in June 2006 [1.] have made it necessary for EDF to modify its ruling principles. These modifications required the restructuring of radiochemical guidelines to better reflect their impact on nuclear safety, the environment and radioprotection. In accordance with these aims, a new authoritative document has been produced. This ruling document identifies all parameters with a potential impact on nuclear safety, radiological releases to the environment and personnel dose rates. These diagnostic and control parameters have been identified for a reactor in production and for a reactor during shutdown. For parameters related to a reactor in production, some indicators are used to evaluate impacts on availability, radioprotection and the environment during shutdown and on outage and to anticipate mitigation ways. On the other side, several parameters related to the stages of shutdown were also directly evaluated in order to minimize the impacts. This paper describes the EDF methodology used to establish operational documents: radiochemical guidelines and process specifications, and includes the following: - description of monitored parameters and their associated areas of risk; - justification of target values, frequencies of inspection and the required actions for the monitored parameters. The sizing methodology is based on theoretical studies and on EDF operational experience analysis. By implementing in the operational and technical specifications requirements linked to nuclear safety, radioprotection and environment respect, EDF will benefit from an improved compromise between these areas as well as an increased focus. (authors)

Evaluation of radiochemical data usability

International Nuclear Information System (INIS)

Paar, J.G.; Porterfield, D.R.

1997-04-01

This procedure provides a framework for implementation of radiochemical data verification and validation for environmental remediation activities. It has been developed through participation of many individuals currently involved in analytical radiochemistry, radiochemical validation, and validation program development throughout the DOE complex. It should be regarded as a guidance to use in developing an implementable radiochemical validation strategy. This procedure provides specifications for developing and implementing a radiochemical validation methodology flexible enough to allow evaluation of data useability for project-specific Data Quality Objectives (DQO). Data produced by analytical methods for which this procedure provides limited guidance are classified as open-quotes non-routineclose quotes radionuclides and methods, and analyses by these methods may necessitate adoption of modified criteria from this procedure

Rapid Radiochemical Methods for Asphalt Paving Material ...

Science.gov (United States)

Technical Brief Validated rapid radiochemical methods for alpha and beta emitters in solid matrices that are commonly encountered in urban environments were previously unavailable for public use by responding laboratories. A lack of tested rapid methods would delay the quick determination of contamination levels and the assessment of acceptable site-specific exposure levels. Of special concern are matrices with rough and porous surfaces, which allow the movement of radioactive material deep into the building material making it difficult to detect. This research focuses on methods that address preparation, radiochemical separation, and analysis of asphalt paving materials and asphalt roofing shingles. These matrices, common to outdoor environments, challenge the capability and capacity of very experienced radiochemistry laboratories. Generally, routine sample preparation and dissolution techniques produce liquid samples (representative of the original sample material) that can be processed using available radiochemical methods. The asphalt materials are especially difficult because they do not readily lend themselves to these routine sample preparation and dissolution techniques. The HSRP and ORIA coordinate radiological reference laboratory priorities and activities in conjunction with HSRP’s Partner Process. As part of the collaboration, the HSRP worked with ORIA to publish rapid radioanalytical methods for selected radionuclides in building material matrice

Continuous radiochemical analysis of fission products in a nuclear reactor water coolant

International Nuclear Information System (INIS)

Moskvin, L.N.; Zakharov, L.K.; Leont'ev, G.G.; Mel'nikov, V.A.; Orlenkov, I.S.; Slutskij, G.K.

1975-01-01

Method for continuous radiochemical analysis of I, Cs, Ba, Sr and Ce isotopes in a reactor water heat-transfer agent was developed. A continuous two-dimensional chromatographic process of complex mixtures separation of substances proved to be feasible on several parallel sorbent layers, which moved at constant velocities and separated by stationary intermediate collectors. Tests on model solutions containing I, Ce, Cs and Ba isotopes and on heat-carrier samples showed quantitative separation of elements. The results were indicative of a basic possibility of using multisorbent chromatographs for continuous control of multicomponent mixtures, particularly for control of radioactive fission product compositions in water heat-transfer agents in nuclear power plants. A diagram is shown for a two-dimensional chromatographic separation of a multicomponent mixture. Also shown is a flow chart of an installation for continuous control of iodine and cesium isotope activities

Obtention process of phosphorus 32 starting from commercial sulfur and design and construction of the radiochemical separation prototype

International Nuclear Information System (INIS)

Duarte A, C.; Alanis M, J.; Gutierrez R, C.

2002-01-01

In this work an obtention process of phosphorus 32 ( 32 P) in orthophosphoric acid form (H 3 32 PO 4 ) is described starting from commercial sulfur. Also the design and construction of the experimental prototype used in the radiochemical separation and their results in three tests carried out is reported. (Author)

Hanford Environmental Restoration data validation process for chemical and radiochemical analyses

International Nuclear Information System (INIS)

Adams, M.R.; Bechtold, R.A.; Clark, D.E.; Angelos, K.M.; Winter, S.M.

1993-10-01

Detailed procedures for validation of chemical and radiochemical data are used to assure consistent application of validation principles and support a uniform database of quality environmental data. During application of these procedures, it was determined that laboratory data packages were frequently missing certain types of documentation causing subsequent delays in meeting critical milestones in the completion of validation activities. A quality improvement team was assembled to address the problems caused by missing documentation and streamline the entire process. The result was the development of a separate data package verification procedure and revisions to the data validation procedures. This has resulted in a system whereby deficient data packages are immediately identified and corrected prior to validation and revised validation procedures which more closely match the common analytical reporting practices of laboratory service vendors

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.)

Intermediate Levels of Visual Processing

National Research Council Canada - National Science Library

Nakayama, Ken

1998-01-01

...) surface representation, here we have shown that there is an intermediate level of visual processing, between the analysis of the image and higher order representations related to specific objects; (2...

Fifty years of radiochemical tracers

International Nuclear Information System (INIS)

Evans, E.A.

1992-01-01

During the past 50 years radiochemical tracers, usually in the form of isotopically labelled organic compounds, have been essential tools to further advance our knowledge at the frontiers of a great variety of scientific developments in the life sciences. This plenary lecture reviews necessarily selected highlights in the synthesis and applications of such radiochemical tracers. Included are examples where important advances, made possible by using radiochemicals, have contributed to improving the quality of life on this planet. The principal radioisotopes involved, 14 C, 3 H, 35 S, 32 P, 125 I, are all relatively safe to handle and are commercially available at maximum theoretical specific activity (carrier free). The compounds labeled with these radioisotopes are used in many fields of research which include biosynthesis and biotechnology studies, cell biology, drug metabolism, clinical research and environmental applications, and are briefly reviewed. (author). 55 refs

The publication lapse of papers in Radiochemical and Radioanalytical Letters

International Nuclear Information System (INIS)

Braun, T.; Nagydiosi-Kocsis, Gy.

1982-01-01

The time needed for passing through journal editorial and publication processing has been examined for the papers published in Radiochemical and Radioanalytical Letters for the years 1969-1981. (author)

Thorium base fuels reprocessing at the L.P.R. (Radiochemical Processes Laboratory) experimental plant

International Nuclear Information System (INIS)

Almagro, J.C.; Dupetit, G.A.; Deandreis, R.A.

1987-01-01

The availability of the LPR (Radiochemical Processes Laboratory) plant offers the possibility to demonstrate and create the necessary technological basis for thorium fuels reprocessing. To this purpose, the solvents extraction technique is used, employing TBP (at 30%) as solvent. The process is named THOREX, a one-cycle acid, which permits an adequate separation of Th 232 and U 233 components and fission products. For thorium oxide elements dissolution, the 'chopp-leach' process (installed at LPR) is used, employing a NO 3 H 13N, 0.05M FH and 0.1M Al (NO 3 ) 3 , as solvent. To adapt the pilot plant to the flow-sheet requirements proposed, minor modifications must be carried out in the interconnection of the existing decanting mixers. The input of the plant has been calculated by Origin Code modified for irradiations in reactors of the HWR type. (Author)

Intermediate organizations in the innovation process in Mexico

Directory of Open Access Journals (Sweden)

Maria del Pilar Monserrat Pérez Hernández

2016-07-01

Full Text Available The innovation activity depends strongly on the interaction between generating actors and end-users of new knowledge and technologies. There are several intermediate organizations (IO that facilitate translating the needs of the users with the new technologies that are beingdeveloped, in order to satisfy more effectively their demands. This paper analyzes the mediation process involved in the IO in innovative activity in Mexico, to identify structural holes in the innovation process. The relevant results in the Mexican intermediation process points that threeimportant structural holes of the process are missing: one between the negotiation process and sponsorship, the second in marketing and commercial profit of the obtained results and the last one in the regulation and referring activities. It is very important that the detected missinglinks in the intermediation process are filled, because they can hinder considerably the overall profit and benefits that society could obtained of the innovation process.

Radiochemical solar neutrino experiments

International Nuclear Information System (INIS)

Rich, R.; Spiro, M.

1993-01-01

This review covers the three presently running radiochemical solar neutrino experiments, namely the Chlorine, SAGE, and GALLEX experiments. The focus of the review is on a discussion of statistical consistency checks of the available data. The chlorine radiochemical experiment is conceptually simple and shows no strong indication of any statistical anomalies. It still forms the basis of the solar neutrino problem. Each of the two gallium experiments show internal statistical consistency. SAGE's recent preliminary results are consistent with the published GALLEX results. If this convergence is confirmed by a more definitive analysis, this would suggest that the combined result of the two gallium experiments, SAGE and GALLEX, be used for comparisons with theoretical expectations. 5 refs., 15 figs

The use of robots for automation in the radiochemical laboratory

International Nuclear Information System (INIS)

Huddleston, J.

1988-01-01

The use of robotic systems for automated processes such as overnight operations, procedures involving radiation hazards in radiochemical laboratories is discussed. Particular reference is made to their use in analytical problems. Their flexibility is emphasised. (U.K.)

Safety assessment for TA-48 radiochemical operations

International Nuclear Information System (INIS)

1994-08-01

The purpose of this report is to document an assessment performed to evaluate the safety of the radiochemical operations conducted at the Los Alamos National Laboratory operations area designated as TA-48. This Safety Assessment for the TA-48 radiochemical operations was prepared to fulfill the requirements of US Department of Energy (DOE) Order 5481.1B, ''Safety Analysis and Review System.'' The area designated as TA-48 is operated by the Chemical Science and Technology (CST) Division and is involved with radiochemical operations associated with nuclear weapons testing, evaluation of samples collected from a variety of environmental sources, and nuclear medicine activities. This report documents a systematic evaluation of the hazards associated with the radiochemical operations that are conducted at TA-48. The accident analyses are limited to evaluation of the expected consequences associated with a few bounding accident scenarios that are selected as part of the hazard analysis. Section 2 of this report presents an executive summary and conclusions, Section 3 presents pertinent information concerning the TA-48 site and surrounding area, Section 4 presents a description of the TA-48 radiochemical operations, and Section 5 presents a description of the individual facilities. Section 6 of the report presents an evaluation of the hazards that are associated with the TA-48 operations and Section 7 presents a detailed analysis of selected accident scenarios

Radiochemical procedures and techniques

International Nuclear Information System (INIS)

Flynn, K.

1975-04-01

A summary is presented of the radiochemical procedures and techniques currently in use by the Chemistry Division Nuclear Chemistry Group at Argonne National Laboratory for the analysis of radioactive samples. (U.S.)

Radiochemical stability of radiopharmaceutical preparations

International Nuclear Information System (INIS)

Martins, Patricia de A.; Silva, Jose L. da; Ramos, Marcelo P.S.; Oliveira, Ideli M. de; Felgueiras, Carlos F.; Herrerias, Rosana; Zapparoli Junior, Carlos L.; Mengatti, Jair; Fukumori, Neuza T.O.; Matsuda, Margareth M.N.

2011-01-01

The 'in vitro' stability studies of the radiopharmaceutical preparations are an essential requirement for routine practice in nuclear medicine and are an important parameter for evaluating the quality, safety and efficacy required for the sanitary registration of pharmaceutical products. Several countries have published guidelines for the evaluation of pharmaceutical stability. In Brazil, the stability studies should be conducted according to the Guide for Conducting Stability Studies published in the Resolution-RE n. 1, of 29th July 2005. There are also for radiopharmaceutical products, two specific resolutions: RDC-63 regulates the Good Manufacturing Practices for Radiopharmaceuticals and RDC-64 provides the Registration of Radiopharmaceuticals, both published on the 18th December 2009. The radiopharmaceutical stability is defined as the time during which the radioisotope can be safely used for the intended purpose. The radiochemical stability can be affected by a variety of factors, including storage temperature, amount of radioactivity, radioactive concentration, presence or absence of antioxidants or other stabilizing agents. The radiochemical stability studies must be established under controlled conditions determined by the effective use of the product. The aim of this work was to evaluate the radiochemical stability of labeled molecules with 131 I, 123 I, 153 Sm, 18 F, 51 Cr, 177 Lu and 111 In as well as 67 Ga and 201 Tl radiopharmaceuticals. Radiochemical purity was evaluated after production and in the validity period, with the maximum activity and in the recommended storage conditions. The analyses were carried out by thin-layer silica gel plate, paper chromatography and gel chromatography. The experimental results showed to be in accordance with the specified limits for all the analysed products. (author)

Radiochemical Solar Neutrino Experiments - Successful and Otherwise

International Nuclear Information System (INIS)

Hahn, R.L.

2008-01-01

Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ( 37 Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ( 71 Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled

Radiochemical solar neutrino experiments, 'successful and otherwise'

International Nuclear Information System (INIS)

Hahn, Richard L

2008-01-01

Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ( 37 Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ( 71 Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled.

Radiochemicals

International Nuclear Information System (INIS)

1980-01-01

In this catalogue those radioactive chemicals for research are listed which are produced by the Radiochemical Centre Amersham and our laboratories at Brunswick. The dates given for each product can understandably only be limited within the framework of such a catalogue. Additional dates and references to application technique can be obtained from us any time. Our programme is continually updated by new products. If a compound not listed in the catalogue should be required we ask for inquiry. Our working team for special syntheses will try to produce it according to our possibilities and our requirements. (orig.) [de

Intermediate product selection and blending in the food processing industry

DEFF Research Database (Denmark)

Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter

2013-01-01

This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates...

Hanford radiochemical site decommissioning demonstration program

International Nuclear Information System (INIS)

Nelson, D.C.

1971-01-01

A program is proposed for the innovation, development, and demonstration of technologies necessary to decommission the Hanford radiochemical plant area to the extent that the sites can have unrestricted public access. The five tasks selected for development and demonstration of restoration techniques were restoration of a burial ground, decommissioning of a separations plant, restoration of a separations plant waste interim storage tank farm, restoration of a liquid disposal area, and disposal of large contaminated equipment. Process development requirements are tabulated and discussed. A proposed schedule and estimated costs are given

Intermediate product selection and blending in the food processing industry

NARCIS (Netherlands)

Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter; Grunow, Martin

2013-01-01

This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates are

Evolution and applications of radiochemical procedures. From Marie Curie to Darleane Hoffman

International Nuclear Information System (INIS)

Contis, E. T.; Rengan, K.

1996-01-01

Marie Curie carried out the first radiochemical separations which eventually lead to the discovery of polonium and radium, two new elements. Nearly a century later Darleane Hoffman and her collaborators are devising new radiochemical separation procedures for studying the chemical properties of newly discovered transactinide elements. Safety requirements as well as changes necessitated by fast decaying radionuclides have transformed the nature of radiochemical separations. Further, applications in a wide variety of areas such as analysis of trace elements in food to radioimmunoassay have broadened the use of radiochemical separations. Examples of some early, historically important, radiochemical separations are described in this article. In addition, recent trends in the use of radiochemical separations in neutron activation analysis, in dating applications, in fission product studies and in the study of transactinide elements are briefly described with specific examples. (author). 52 refs

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.)

Processing and validation of intermediate energy evaluated data files

International Nuclear Information System (INIS)

2000-01-01

Current accelerator-driven and other intermediate energy technologies require accurate nuclear data to model the performance of the target/blanket assembly, neutron production, activation, heating and damage. In a previous WPEC subgroup, SG13 on intermediate energy nuclear data, various aspects of intermediate energy data, such as nuclear data needs, experiments, model calculations and file formatting issues were investigated and categorized to come to a joint evaluation effort. The successor of SG13, SG14 on the processing and validation of intermediate energy evaluated data files, goes one step further. The nuclear data files that have been created with the aforementioned information need to be processed and validated in order to be applicable in realistic intermediate energy simulations. We emphasize that the work of SG14 excludes the 0-20 MeV data part of the neutron evaluations, which is supposed to be covered elsewhere. This final report contains the following sections: section 2: a survey of the data files above 20 MeV that have been considered for validation in SG14; section 3: a summary of the review of the 150 MeV intermediate energy data files for ENDF/B-VI and, more briefly, the other libraries; section 4: validation of the data library against an integral experiment with MCNPX; section 5: conclusions. (author)

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)

Radiochemical analysis of phosphorus in milk samples

International Nuclear Information System (INIS)

Oliveira, R.M. de; Cunha, I.I.L.

1991-01-01

The determination of phosphorus in milk samples by thermal neutron activation analysis employing radiochemical separation is described. The radiochemical separation consists of the simultaneous irradiation of samples and standards, dissolution of the milk samples in a perchloric acid and nitric acid mixture, addition of zinc hold-back carrier, precipitation of phosphorus as ammonium phospho molybdate (A.M.P.) and sample counting in a Geiger-Mueller detector. The analysis sources of error were studied and the established method was applied to phosphorus analyses in commercial milk samples. (author)

Formation of large target residues in intermediate energy nuclear collisions

International Nuclear Information System (INIS)

Loveland, W.; Aleklett, K.; Sihver, L.; Xu, Z.; Seaborg, G.T.

1987-04-01

We have used radiochemical techniques to measure the yields, angular distributions and velocity spectra of the large (A/sub frag/ ≥ 2/3 A/sub tgt/) target residues from the fragmentation of 197 Au by intermediate energy 12 C, 20 Ne, 32 S, 40 Ar, 84 Kr, and 139 La projectiles. The fragment moving frame angular distributions are asymmetric for the lighter projectiles (C-Ar). The fragment velocity spectra are Maxwellian for the Kr induced reactions and non-Maxwellian for the reactions induced by the lighter ions. We interpret these results in terms of a change in the dominant fragment production mechanism(s) from one(s) involving a fast non-equilibrium process for the lighter ions to a slow, equilibrium process for Kr. Comparison of the measured yields and angular distributions with calculations made using a Boltzmann transport equation with appropriate modifications for Pauli blocking, etc., show excellent agreement between data and theory. 12 refs., 12 figs

Instrumentation for chemical and radiochemical monitoring in nuclear power plants

International Nuclear Information System (INIS)

Nordmann, F.; Ballard, G.

2009-01-01

This article details the instrumentation implemented in French nuclear power plants for the monitoring of chemical and radiochemical effluents with the aim of limiting their environmental impact. It describes the controls performed with chemical automata for the search for drifts, anomalies or pollution in a given circuit. The operation principles of the different types of chemical automata are explained as well as the manual controls performed on samples manually collected. Content: 1 - general considerations; 2 - objectives of the chemical monitoring: usefulness of continuous monitoring with automata, transmission to control rooms and related actions, redundancy of automata; 3 - instrumentation and explanations for the main circuits: principle of chemical automata monitoring, instrumentation of the main primary circuit, instrumentation of the main secondary circuit, instrumentation of the tertiary circuit, preparation of water makeup (demineralized water), other loops, instrumentation for effluents and environment monitoring, measurement principles of chemical automata, control and maintenance of chemical automata; 4 - manual controls after sampling; 5 - radiochemical monitoring: automatized radiochemical measurements, manual radiochemical measurements; 6 - conclusion

Present status and perspective of radiochemical analysis of radionuclides in Nordic countries

DEFF Research Database (Denmark)

Hou, Xiaolin; Olsson, Mattias; Togneri, Laura

2016-01-01

Radiochemical analysis plays a critical role in the determination of pure beta and alpha emitting radionuclides for environmental monitoring, radioecology, decommissioning, nuclear forensics and geological dating. A remarkable development on radiochemical analysis has been achieved in the past...... of radionuclides, especially in Nordic countries; some requirements from nuclear industries and research organizations, as well as perspectives on the development of radiochemical analysis are discussed....

Some problems concenrning the use of automated radiochemical separation systems in destructive neutron activation analysis

International Nuclear Information System (INIS)

Nagy, L.G.; Toeroek, G.

1977-01-01

The present state of a long term program is reviewed. It was started to elaborate a remote controlled automated radiochemical processing system for the neutron activation analysis of biological materials. The system is based on wet ashing of the sample followed by reactive desorption of some volatile components. The distillation residue is passed through a series of columns filled with selective ion screening materials to remove the matrix activity. The solution is thus ''stripped'' from the interfering radioions, and it is processed to single-elements through group separations using ion-exchange chromatographic techniques. Some special problems concerning this system are treated. (a) General aspects of the construction of a (semi)automated radiochemical processing system are discussed. (b) Comparison is made between various technical realizations of the same basic concept. (c) Some problems concerning the ''reconstruction'' of an already published processing system are outlined. (T.G.)

Role of interference of states of intermediate nuclei in exchange processes

International Nuclear Information System (INIS)

Belyaeva, T.L.; Zelenskaya, N.S.; Teplov, I.B.

1982-01-01

Role of interference of intermediate nucleus states for exchange processes in reactions with alpha particles on 11 B, 7 Li and 6 Li light nuclei was investigated when considering exactly the process dynamics in the method of distorted waves with a finite interaction radius. The process dynamics, in particular, the overlapping degree of wave functions of bound states and interaction potentials, affects considerably the reaction cross section in the rections with alpha particles on nuclei of 1p shell. If in the reaction selection rules permit the excitation of components of intermediate system states with maximum values of #betta# 1 and #betta# 2 orbital moments at the given N 1 and N 2 , the contribution of such components to the cross section will be determining. When components of intermediate system states with maximum #betta# 1 (or #betta# 2 ) are forbidden with selection rules, several intermediate states can have approximately similar overlapping integrals

Remote-controlled module-assisted synthesis of O-(2-[18F]fluoroethyl)-L-tyrosine as tumor PET tracer using two different radiochemical routes

International Nuclear Information System (INIS)

Wang Mingwei; Yin Duanzhi; Zhang Lan; Zhou Wei; Wang Yongxian

2006-01-01

The positron-emitter fluorine-18 labeled amino acid O-(2-[ 18 F]fluoroethyl)-L-tyrosine ([ 18 F]FET) has shown very promising perspectives for brain tumor diagnosis with positron emission tomography (PET). There have been two existing preparation routes of [ 18 F]FET named direct nucleophilic radiofiuorination of protected L-tyrosine and radiofiuoroallcylation of unprotected L-tyrosine, respectively. A general module was designed specifically for the routine synthesis of [ 18 F]FET, which could be suitable for the present two chemical methods with simple modifications. The fluorinated intermediates and the final product were separated and purified using solid phase extraction (SPE) on the Sep-Pak silica plus cartridge instead of the time-consuming high performance liquid chromatography (HPLC) procedures. The total synthesis time was about 50-60 rain with good radiochemical yield (about 20-40%, no-decay-corrected) and good radiochemical purity (more than 97%) for both the synthetic methods. (authors)

Radiochemical analysis of military nuclear facilities

International Nuclear Information System (INIS)

Bayramov, A.A.; Bayramova, S.M.

2012-01-01

Full text : Radiochemical Analysis is a branch of analytical chemistry comprising an aggregate of methods for qualitatively determining the composition and content of radioisotopes in the products of transformations. Safety and minimization of radiation impact on human and environment are important demand of operation of Military Nuclear Facilities (MNF). In accordance of recommendations of International Commission on Radiological Protection there are next objects of radiochemical analysis: 1) potential sources of radiochemical pollution; 2) environment (objects of environment, human environment including buildings, agricultural production, water, air et al.); 3) human himself (determination of dose from external and internal radiation, chemical poisoning). The chemical analysis can be carried out using, for example, the Gas Chromatography instrument whish separates chemical mixtures and identifies the components at a molecular level. It is one of the most accurate tools for analyzing environmental samples. The Gas Chromatography works on the principle that a mixture will separate into individual substances when heated. The heated gases are carried through a column with an inert gas (such as helium). As the separated substances emerge from the column opening, they flow into the Mass Spectrometry. Mass spectrometry identifies compounds by the mass of the analyte molecule. Newly developed portable Gas Chromatography and Mass Spectrometry are techniques that can be used to separate volatile organic compounds and pesticides. Other uses of Gas Chromatography, combined with other separation and analytical techniques, have been developed for radionuclides, explosive compounds such as royal demolition explosive and trinitrotoluene, and metals. So, based on the many years experience of operation of dangerous MNF, in concordance with norms of radiation and chemical safety it was considered that the tasks of the radiochemical analysis of Military Nuclear Facilities include

11th radiochemical conference

International Nuclear Information System (INIS)

Prasil, Z.

1987-01-01

The conference met in four sesions which discussed: Separation methods, Radioanalytical methods, Labelled compounds and Miscellaneous. The first session discussed extraction methods, ion exchange and chromatographic separation of radioisotopes. The second session heard papers on the application of these methods, e.g., in geochemistry, on the use of radioactive tracers in radiochemical analysis and the use of activation analysis in the determination of trace elements. The third session heard papers on the preparation of labelled organic compounds with isotopes 3 H, 14 C, radioiodine and 32 P, on the preparation of RIA kits and on the chemistry and radiopharmacology of technetium compounds. The other contributions which could not be heard in any of the three sessions discussed, e.g., the preparation of elements on the cyclotron and microtron, the production of a new 99m Tc-generator, the participation of the IAEA in processing low- and medium-level radioactive wastes, etc. (E.S.)

Radiochemical schemes of obtaining 89Sr and 90Y radionuclides

International Nuclear Information System (INIS)

Usarov, Z. O.

2010-03-01

Key words: strontium-89, yttrium-90, extraction and extraction-chromatographic purification of radionuclides, radiopharmaceuticals. Subjects of research: strontium-89 and yttrium-90 radionuclides and their chloride forms. Purpose of work is developing of radiochemical technologies on obtaining of 89 Sr and 90 Y on the WWR-SM reactor with high radionuclide purity. Methods of research: extraction and extraction-chromatographic methods of radionuclides separation, beta- and gamma-spectrometric methods of activity measuring. The results obtained and their novelty: Were determined the conformity to laws of Y and Sr distribution in two-phase systems TBP-HNO 3 , TBP-NH 4 NO 3 , TBP-HCI, HDEHP-NO 3 , HDEHP-NH 4 NO 3 and HDEHP-HCI. Were determined the conformity to laws of Y and Sr distribution in systems with craun ethers DB-18K-6 and DTBDB-18K-6 from water solutions of HNO 3 . Radiochemical technologies on obtaining of 89 Sr and 90 Y radionuclides including radiochemical process of yttrium target with using the systems TBP-HNO 3 and HDEHP/Teflone were developed. Practical value: the radiochemical technology of obtaining 89 Sr with high radionuclide purity was developed. The method of preparation a chloride compound of 89 SrCl 2 which is used as a drug form for preparation of 89 Sr- 'Metastron' was developed. The relatively simple method of on the way obtaining 90 Y in the reactor with high radionuclidic purity that is useful for follow using in medical practice was offered. Degree of embed and economic effectivity: the developed technologies have approbation in manufacturing conditions in Radiopreparat Enterprise of INP AS RU and were offered for receiving of domestic preparations against of import foreign analogues. The statement about using the invention by obtained patent is attached to dissertation. Field of application: the received results will be introduced in manufacture at Radiopreparat Enterprise of INP AS RU for receiving of domestic preparations

Description of project for pretreatment and storage of wastes of L.P.R. (Radiochemical Processes Laboratory)

International Nuclear Information System (INIS)

Doval, J.C.F.; Mehlich, A.M.; Quilici, D.F.

1987-01-01

The aim of the project is to allow the start up and operation of LPR (Radiochemical Processes Laboratory) as part of the intended activities in the plant. In this paper, the pretreatment and storage of liquid wastes generated at the LPR are described. The pretreatment section will be set up inside the shielded cells already existent in the LPR, where a previous concentration through the evaporation of liquid wastes will take place. The storage section has to be constructed on purpose in order to temporarily store the concentrates. The cells of transference and preconditioning of solid wastes are also described. These cells will be mounted inside the building, allowing the handling of radioactive solids generated as effluents during the reprocessing plan. In the description, the use of non conventional materials for the boiler making and the construction of cells is specially mentioned. (Author)

Methods for training radiochemical technicians at ORNL

International Nuclear Information System (INIS)

Parrott, J.R.; Nicol, R.G.

1975-01-01

The training of personnel to carry out radiochemical operations at ORNL is a formidable and recurrent task since repetitive, production-type operations are not involved, and programs are constantly shifting. It is essential that provisions be made for the routine retraining of personnel if they are to make effective contributions on a continuing basis. The present training methods have emerged as a result of thirty years experience in a variety of radiochemical pilot-plant programs. These programs have included operations performed in glove boxes, hot-cell manipulator work handling high-neutron-emitting isotopes, and the entire spectrum of remote solvent extraction operations. Present methods of training and the results obtained are summarized

Computer aided piping layout design in radiochemical plants- an improved software package

International Nuclear Information System (INIS)

Raju, R.P.; Siddiqui, H.R.

1995-01-01

A software package was developed and it was successfully implemented for the piping layout design of the four process cells of the Kalpakkam Reprocessing Project. This paper discusses in detail all the improvements and modifications that are being carried out in the package so that it becomes more meaningful and useful for implementation for the forthcoming radiochemical plants

Simplification of Process Integration Studies in Intermediate Size Industries

DEFF Research Database (Denmark)

Dalsgård, Henrik; Petersen, P. M.; Qvale, Einar Bjørn

2002-01-01

associated with a given process integration study in an intermediate size industry. This is based on the observation that the systems that eventually result from a process integration project and that are economically and operationally most interesting are also quite simple. Four steps that may be used......It can be argued that the largest potential for energy savings based on process integration is in the intermediate size industry. But this is also the industrial scale in which it is most difficult to make the introduction of energy saving measures economically interesting. The reasons......' and therefore lead to non-optimal economic solutions, which may be right. But the objective of the optimisation is not to reach the best economic solution, but to relatively quickly develop the design of a simple and operationally friendly network without losing too much energy saving potential. (C) 2002...

Trace analysis measurements in high-purity aluminium by means of radiochemical neutron and proton activation analysis

International Nuclear Information System (INIS)

Egger, K.P.

1987-01-01

The aim of the study consisted in the development of efficient radiochemical composite processes and activation methods for the multi-element determination of traces within the lower ng range in high-purity aluminium. More than 50 elements were determined with the help of activation with reactor neutrons; the selective separation of matrix activity (adsorption with hydrated antimony pentoxide) led to a noticeable improvement of detectability, as compared with instrumental neutron activation analysis. Further improvements were achieved with the help of radiochemical group separations in ion exchangers or with the help of the selective separation of the pure beta-emitting elements. Over 20 elements up to high atomic numbers were determined by means of activating 13 MeV protons and 23 Me protons. In this connection, improvements of the detection limit by as a factor of 10 were achieved with radiochemical separation techniques, as compared with pure instrumental proton activation analysis. (RB) [de

Ultratrace determination of platinum in biological materials via neutron activation and radiochemical separation

International Nuclear Information System (INIS)

Zeisler, R.; Greenberg, R.R.

1982-01-01

A neutron activation analysis scheme based upon a radiochemical separation of the activation products has been developed. The method utilizes the inherent sensitivity of the activation reaction 198 Pt(n,ν) 199 Pt and counting of the daughter nuclide 199 Au. This nuclide is radiochemically separated from interfering activities by homogeneous precipitation as elemental gold. The remaining interference of the secondary reaction 197 Au(n,ν) 198 Au(n,ν) 199 Au from gold in the samples is quantitatively assessed and corrected. During this process accurate gold concentrations in the samples are obtained at ultratrace levels. The analysis scheme is applied to gold and platinum determinations in biological Standard Reference Materials and human liver specimens. Gold and platinum are determined at concentrations of 5x10 - 11 g/g, and at higher levels. (author)

Radiochemical Means of Investigating Delayed Neutron Precursors

International Nuclear Information System (INIS)

Marmol, P. del

1968-01-01

Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope separator techniques; it is concluded that the methods are complementary. (author)

Radiochemical Means of Investigating Delayed Neutron Precursors

International Nuclear Information System (INIS)

Marmol, P. del

1968-01-01

Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot-atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope-separator techniques; it is concluded that the methods are complementary. (author)

Radiochemical methods to enhance efficiency of α-spectral measurements

International Nuclear Information System (INIS)

Silkina, G.P.; Artem'ev, O.I.

2001-01-01

The paper describes possible ways to improve a plutonium radiochemical separation technique developed in the Khlopin Radium Institute and modify it to account for the site-specific features of samples from the former Semipalatinsk test site (STS) and enhance the alpha spectrometry efficiency.The paper describes possible ways to improve a plutonium radiochemical separation technique developed in the Khlopin Radium Institute and modify it to account for the site-specific features of samples from the former Semipalatinsk test site (STS) and enhance the alpha spectrometry efficiency. (author)

Digital intermediate frequency QAM modulator using parallel processing

Science.gov (United States)

Pao, Hsueh-Yuan [Livermore, CA; Tran, Binh-Nien [San Ramon, CA

2008-05-27

The digital Intermediate Frequency (IF) modulator applies to various modulation types and offers a simple and low cost method to implement a high-speed digital IF modulator using field programmable gate arrays (FPGAs). The architecture eliminates multipliers and sequential processing by storing the pre-computed modulated cosine and sine carriers in ROM look-up-tables (LUTs). The high-speed input data stream is parallel processed using the corresponding LUTs, which reduces the main processing speed, allowing the use of low cost FPGAs.

Radiochemical purity determination by paper chromatography 2

International Nuclear Information System (INIS)

1975-01-01

The standard relates to the determination of radiochemical impurities in labelled compounds using paper chromatography. The basic terms are given as is the description of procedure and evaluation of chromatograms. (E.S.)

Present status of radiochemical double β decay study (238U)

International Nuclear Information System (INIS)

Chevallier, A.; Chevallier, J.; Escoubes, B.; Schulz, N.; Sens, J.C.; Madic, C.; Maillard, C.

1989-01-01

The reasons for which the 238 U is a suitable candidate for the β β decay processes are explained. The strategy adopted for the radiochemical separation of the 234 U is given. A chemical system based on extraction chromatography is applied. The Pu IV breakthrough curves obtained at 40C during 238 Pu/ 238 U separation cycles are presented. A short description of the chromatographic facility is given. The solution adopted for the low background α spectrometer is explained

Radiochemical analysis for nuclear waste management in decommissioning

International Nuclear Information System (INIS)

Hou, X.

2010-07-01

The NKS-B RadWaste project was launched from June 2009. The on-going decommissioning activities in Nordic countries and current requirements and problems on the radiochemical analysis of decommissioning waste were discussed and overviewed. The radiochemical analytical methods used for determination of various radionuclides in nuclear waste are reviewed, a book was written by the project partners Jukka Lehto and Xiaolin Hou on the chemistry and analysis of radionuclide to be published in 2010. A summary of the methods developed in Nordic laboratories is described in this report. The progresses on the development and optimization of analytical method in the Nordic labs under this project are presented. (author)

Radiochemical studies of some preparation methods for phosphorus

International Nuclear Information System (INIS)

Loos-Neskovic, C.; Fedoroff, M.

1983-01-01

Various methods of radiochemical separation were tested for the determination of phosphorus in metals and alloys by neutron activation analysis. Classical methods of separation revealed some defects when they were applied to this problem. Methods using liquid extraction gave low yields and were not reproducible. Methods based on precipitation gave better results, but were not selective enough in most cases. Retention on alumina was not possible without preliminary separations. Authors studied a new radiochemical separation based on the extraction of elemental phosphorus in the gaseous phase after reduction at high temperature with carbon. Measurements with radioactive phosphorus showed that the extraction yield is better than 99%. (author)

Radiochemical analysis for nuclear waste management in decommissioning

Energy Technology Data Exchange (ETDEWEB)

Hou, X. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy. Radiation Research Div., Roskilde (Denmark))

2010-07-15

The NKS-B RadWaste project was launched from June 2009. The on-going decommissioning activities in Nordic countries and current requirements and problems on the radiochemical analysis of decommissioning waste were discussed and overviewed. The radiochemical analytical methods used for determination of various radionuclides in nuclear waste are reviewed, a book was written by the project partners Jukka Lehto and Xiaolin Hou on the chemistry and analysis of radionuclide to be published in 2010. A summary of the methods developed in Nordic laboratories is described in this report. The progresses on the development and optimization of analytical method in the Nordic labs under this project are presented. (author)

OPERATIONAL EXPERIENCE: UPGRADED MPC AND A SYSTEMS FOR THE RADIOCHEMICAL PLANT OF THE SIBERIAN CHEMICAL COMBINE

International Nuclear Information System (INIS)

RODRIGUEZ, C.; GOLOSKOKOV, I.; FISHBONE, L.; GOODEY, K.; LOOMIS, M.; CRAIN, B. JR.; LARSEN, R.

2003-01-01

The success of reducing the risk of nuclear proliferation through physical protection and material control/accounting systems depends upon the development of an effective design that includes consideration of the objectives of the systems and the resources available to implement the design. Included among the objectives of the design are facility characterization, definition of threat, and identification of targets. When considering resources, the designer must consider funds available, rapid low-cost elements, technology elements, human resources, and the availability of resources to sustain operation of the end system. The Siberian Chemical Combine (SCC) is a multi-function nuclear facility located in the Tomsk region of Siberia, Russia. Beginning in 1996, SCC joined with the United States Department of Energy (US/DOE) Material Protection, Control, and Accounting (MPC and A) Program to develop and implement MPC and A upgrades for the Radiochemical, Chemical Metallurgical, Conversion, Uranium Enrichment, and Reactor Plants of the SCC. At the Radiochemical Plant the MPC and A design and implementation process has been largely completed for the Plutonium Storage Facility and related areas of the Radiochemical Plant. Design and implementation of upgrades for the Radiochemical Plant include rapid physical protection upgrades such as bricking up of doors and windows, and installation of security-hardened doors. Rapid material control and accounting upgrades include installation of modern balances and bar code equipment. Comprehensive MPC and A upgrades include the installation of access controls to sensitive areas of the Plant, alarm communication and display (AC and D) systems to detect and annunciate alarm conditions, closed circuit (CCTV) systems to assess alarm conditions, central and secondary alarm station upgrades that enable security forces to assess and respond to alarm conditions, material control and accounting upgrades that include upgraded physical

Safety decommissioning regulations of radiochemical objects - the problem, requires urgent decision

International Nuclear Information System (INIS)

Rovnyj, S.I.; Arsent'eva, N.V.; Emel'yanov, N.M.; Kolesnikov, V.N.

2001-01-01

The necessity of planning and pursuance of the measures on decommissioning of radiochemical industry is discussed. Technological processes were stopped more than in 30 buildings and constructions of the PO Mayak. The characteristics of the technological buildings to be decommissioned were treated in the context of building peculiarities, function, character and level of contamination. An acceptable variant for reactor decommissioning invites development of the standard-legal aspects [ru

Radiochemistry and radiochemical separations. A current bibliography

International Nuclear Information System (INIS)

Bujdoso, E.

1999-01-01

A current bibliography for years 1993-1996 with 159 references was compiled on radiochemistry and radiochemical separations based on the INIS Atomindex. The references are arranged in alphabetical order of first authors. (N.T.)

Placement of the radiochemical processing plant at Oak Ridge National Laboratory into a safe standby condition

International Nuclear Information System (INIS)

Holladay, D.W.; Bopp, C.D.; Farmer, A.J.; Johnson, J.K.; Miller, C.H.; Powers, B.A.; Collins, E.D.

1986-01-01

Extensive upgrade, cleanup, and decontamination efforts are being conducted for appropriate areas in the Radiochemical Processing Plant (RPP) with the goal of achieving safe standby condition by the end of FY 1989. The ventilation system must maintain containment thus, it is being upgraded via demolition and replacement of marginally adequate ductwork, fans, and control systems. Areas that are being decontaminated and stripped of various services (e.g., piping, ductwork, and process tanks) include hot cells, makeup rooms, and pipe tunnels. Operating equipment that is being decontaminated includes glove boxes and hoods. Replacement of the ventilation system and removal of equipment from pipe tunnels, cells, and makeup rooms are accomplished by contact labor by workers using proper attire, safety rules, and shielding, Removal of contaminated ductwork and piping is conducted with containment enclosures that are strategically located at breakpoints, and methods of separation are chosen to conform with health physics requirements. The methods of cutting contaminated piping and ductwork include portable reciprocating saws, pipe cutters, burning, and plasma torch. Specially designed containment enclosures will be used to prevent the spread of radioactive contamination while maintaining adequate ventilation

Placement of the radiochemical processing plant at Oak Ridge National Laboratory into a safe standby condition

International Nuclear Information System (INIS)

Holladay, D.W.; Bopp, C.D.; Farmer, A.J.; Johnson, J.K.; Miller, C.H.; Powers, B.A.; Collins, E.D.

1986-01-01

Extensive upgrade, cleanup, and decontamination efforts are being conducted for appropriate areas in the Radiochemical Processing Plant (RPP) with the goal of achieving ''safe standby'' condition by the end of FY 1989. The ventilation system must maintain containment; thus, it is being upgraded via demolition and replacement of marginally adequate ductwork, fans, and control systems. Areas that are being decontaminated and stripped of various services (e.g., piping, ductwork, and process tanks) include hot cells, makeup rooms, and pipe tunnels. Operating equipment that is being decontaminated includes glove boxes and hoods. Replacement of the ventilation system and removal of equipment from pipe tunnels, cells, and makeup rooms are accomplished by contact labor by workers using proper attire, safety rules, and shielding. Removal of contaminated ductwork and piping is conducted with containment enclosures that are strategically located at breakpoints, and methods of separation are chosen to conform with health physics requirements. The methods of cutting contaminated piping and ductwork include portable reciprocating saws, pipe cutters, burning, and plasma torch. Specially designed containment enclosures will be used to prevent the spread of radioactive contamination while maintaining adequate ventilation. 6 figs

Enzyme clustering accelerates processing of intermediates through metabolic channeling

Science.gov (United States)

Castellana, Michele; Wilson, Maxwell Z.; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M.; Rabinowitz, Joshua D.; Gitai, Zemer; Wingreen, Ned S.

2015-01-01

We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

Intermediate phase evolution in YBCO thin films grown by the TFA process

International Nuclear Information System (INIS)

Zalamova, K; Pomar, A; Palau, A; Puig, T; Obradors, X

2010-01-01

The YBCO thin film growth process from TFA precursors involves a complex reaction path which includes several oxide, fluoride and oxyfluoride intermediate phases, and the final microstructure and properties of the films are strongly influenced by the morphological and chemical evolution of these intermediate phases. In this work we present a study of the evolution of the intermediate phases involved in the TFA YBCO growth process under normal pressure conditions and we show that the oxygen partial pressure during pyrolysis of the TFA precursors is an important parameter. The Cu phase after the TFA pyrolysis can be either CuO, Cu 2 O or a mixture of both as the oxygen partial pressure is modified. The kinetics evolution of the intermediate phases has been determined for films pyrolysed in oxygen and nitrogen atmospheres and it is concluded that non-equilibrium phase transformations influence the reaction path towards epitaxial YBCO films and its microstructure. The intermediate phase evolution in these two series of films is summarized in kinetic phase diagrams.

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

Proceedings of the Tripartite Seminar on Nuclear Material Accounting and Control at Radiochemical Plants

International Nuclear Information System (INIS)

1999-01-01

The problems of creation and operation of nuclear materials (NM) control and accounting systems and their components at radiochemical plants were discussed in seminar during November 2-6 of 1998. There were 63 Russian and 25 foreign participants in seminar. The seminar programme includes following sessions and articles: the aspects of State NM control and accountancy; NM control and accounting in radiochemical plants and at separate stages of reprocessing of spent nuclear fuel and irradiated fuel elements of commercial reactors; NM control and accountancy in storage facilities of radiochemical plants; NM control and accounting computerization, material balance assessment, preparation of reports; qualitative and quantitative measurements in NM control and accounting at radiochemical plants destructive analysis techniques [ru

Statistical analysis of radiochemical measurements of TRU radionuclides in REDC waste

International Nuclear Information System (INIS)

Beauchamp, J.; Downing, D.; Chapman, J.; Fedorov, V.; Nguyen, L.; Parks, C.; Schultz, F.; Yong, L.

1996-10-01

This report summarizes results of the study on the isotopic ratios of transuranium elements in waste from the Radiochemical Engineering Development Center actinide-processing streams. The knowledge of the isotopic ratios when combined with results of nondestructive assays, in particular with results of Active-Passive Neutron Examination Assay and Gamma Active Segmented Passive Assay, may lead to significant increase in precision of the determination of TRU elements contained in ORNL generated waste streams

Radiochemical syntheses further radiopharmaceuticals for positron emission tomography and new strategies for their production

CERN Document Server

Kilbourn, Michael R; Kilbourn, Michael R

2015-01-01

This book describes methods and procedures for preparing PET radiopharmaceuticals, and highlights new methods for conducting radiochemical reactions with carbon-11 (C11) and fluorine-18 (F18), which are two of the most commonly used radionuclides in positron emission tomography (PET) imaging.     Provides reliable methods for radiochemical syntheses and reactions, including all essential information to duplicate the procedure     Eliminates the time-consuming process of searching journal articles and extracting pertinent details from lengthy experimental sections or supporting information     Focuses on an emerging and important area for pharmaceutical and medical applications     Encompasses technical, regulatory, and application aspects     Includes solid-phase radiochemistry, transition-metal catalyzed radiochemistry, microfluidics, click chemistry, green radiochemistry and new strategies for radiopharmaceutical quality control.

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

Radiochemical studies on nuclear fission at Trombay

Indian Academy of Sciences (India)

227Ac to 245Cm were determined by radiochemical methods which involved ... foil, followed by direct γ counting using high resolution Ge(Li) detector was also ... the stiffness to mass asymmetric distortion decreases on either side of lead.Also ...

Radiochemical synthesis of etomoxir

Energy Technology Data Exchange (ETDEWEB)

Abbas, Hafiz G. [Institute of Nuclear Medicine and Oncology (INMOL), New Campus Road, Lahore (Pakistan); Yunus, M. [University of the Punjab, New Campus Road, Lahore (Pakistan); Feinendegen, Ludwig E., E-mail: feinendegen@gmx.ne [Department of Nuclear Medicine, Heinrich-Heine University Duesseldorf, Wannental 45, 88131 Lindau (Germany)

2011-02-15

Sodium 2-{l_brace}6-(4-chlorophenoxy)hexyl{r_brace}oxirane-2-carboxylate (Etomoxir) inhibits transport of fatty acids via the carnitine shuttle into mitochondria of muscle cells and prevents long chain fatty acids from providing energy through {beta}-oxidation especially for muscle contraction. The objective of this synthesis is to develop a method for radioiodination of Etomoxir in order to explore its potential in diagnostic metabolic studies and molecular imaging. Thus, a method is described for the radiochemical synthesis and purification of ethyl 2-{l_brace}6-(4-[{sup 131}I]iodophenoxy)hexyl{r_brace}oxirane-2-carboxylate (3) and 2-{l_brace}6-(4-[{sup 131}I]iodo-phenoxy)hexyl{r_brace}oxirane-2-carboxylic acid (4). For the synthesis of these new agents, ethyl 2-{l_brace}6-(4-bromophenoxy)hexyl{r_brace}oxirane-2-carboxylate (1) and 2-{l_brace}6-(4-bromophenoxy)hexyl{r_brace}oxirane-2-carboxylic acid (2) were refluxed with [{sup 131}I]NaI in the presence of anhydrous acetone at a temperature of 80 {sup o}C and 90 {sup o}C for a period of 3-4 hours, respectively. The method of radiolabeling, based on the nucleophilic exchange reaction, resulted in a radiochemical yield of 43% and 67% for compounds 3 and 4, respectively. This paper reports on the labeling of etomoxir with radioiodine as {sup 124}I labeled etomoxir may be of great importance in molecular imaging.

Radiochemical methods

International Nuclear Information System (INIS)

Geary, W.J.

1986-01-01

This little volume is one of an extended series of basic textbooks on analytical chemistry produced by the Analytical Chemistry by Open Learning project in the UK. Prefatory sections explain its mission, and how to use the Open Learning format. Seventeen specific sections organized into five chaptrs begin with a general discussion of nuclear properties, types, and laws of nuclear decay and proceeds to specific discussions of three published papers (reproduced in their entirety) giving examples of radiochemical methods which were discussed in the previous chapter. Each section begins with an overview, contains one or more practical problems (called self-assessment questions or SAQ's), and concludes with a summary and a list of objectives for the student. Following the main body are answers to the SAQ's, and several tables of physical constants, SI prefixes, etc. A periodic table graces the inside back cover

Transport description of intermediate processes in heavy ion collisions

International Nuclear Information System (INIS)

Ayik, S.; Shivakumar, B.; Shapira, D.

1986-01-01

An extension of the diffusion model is proposed in order to describe the intermediate processes and the compound nucleus formation in heavy ion collisions. The model describes the intermediate processes and fusion in terms of the formation and the evolution of a long-lived dinuclear molecular complex (DMC) and its subsequent decay by fragmentation. The colliding ions can be trapped into the pocket of the entrance channel nucleus-nucleus potential and a DMC is formed. This DMC acts as a doorway state towards formation of a completely equilibrated compound nucleus (CN). It evolves through the exchange of nucleons to different dinuclear configurations. At each stage of its evolution, there is a finite probability for direct fragmentation into outgoing channels by thermal penetration over the barrier. The doorway states that do not fragment relax into a CN configuration and are identified as the fusion yield. 8 refs

Safety and Waste Management for SAM Radiochemical Methods

Science.gov (United States)

The General Safety and Waste Management page offers section-specific safety and waste management details for the radiochemical analytes included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM).

Decontamination and decommission of a radiochemical laboratory building complex

International Nuclear Information System (INIS)

Zoubek, Norbert

2008-01-01

Full text: Handling of unsealed radioactive substances for research and development purposes in chemical or pharmaceutical industries or research centres as well as production of radioactive substances (e.g. for applications in nuclear medicine or industry) requires operation of special radiochemical laboratories. In general, operation of radiochemical laboratories is strongly regulated by the government and national authorities. The operator needs a permit related to radiological protection. In general, technical requirements for such facilities are very high. To ensure high safety standards with respect to the employees and the environment, several radiological protection measures have to be taken. These measures (for example special shielding or ventilation and waste water systems) depend on various factors, e.g. activity in use, kind of nuclides, chemical properties and volatility of substances. In order to close-down such radiochemical laboratories some radiological protection measures have to be maintained to ensure protection of both humans and the environment induced by possible residual contaminations within the facility including technical inventory. However, a later reuse of the facility as a non-radioactive facility requires removal of all radioactive contamination with respect to national regulation. Resulting radioactive wastes have to be disposed of under control of competent authorities. Based on the experience of a decontamination and decommission project for a former radiochemical laboratory complex, the main steps necessary to release such a facility are discussed. Analytical aspects of initial conditions, necessary organisational structures within the project, resources needed estimation and exploration of the radiological situation in the laboratory, elaboration of a measuring strategy and decontamination methods as well as different waste disposal routes in relation to different waste types are reported. (author)

Determination of thorium in native gold by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Liu, Y.; Kraehenbuehl, U.

1995-01-01

Thorium concentrations in 11 native gold samples from different sources, e.g. placer gold, vein and lode gold were determined. Thorium was determined by radiochemical separation and measurement of protactinium from irradiated native gold samples. The chemical yield of the separation procedures is 90%. Other elements were measured by gamma-ray spectroscopy. The radiochemical separation procedures described in this work make accurate determination of Th concentrations in native gold at picogram concentrations possible. (orig.)

Automated radiochemical synthesis and biodistribution of [11C]l-α-acetylmethadol ([11C]LAAM)

International Nuclear Information System (INIS)

Sai, Kiran Kumar Solingapuram; Fan, Jinda; Tu, Zhude; Zerkel, Patrick; Mach, Robert H.; Kharasch, Evan D.

2014-01-01

Long-acting opioid agonists methadone and l-α-acetylmethadol (LAAM) prevent withdrawal in opioid-dependent persons. Attempts to synthesize [ 11 C]-methadone for PET evaluation of brain disposition were unsuccessful. Owing, however, to structural and pharmacologic similarities, we aimed to develop [ 11 C]LAAM as a PET ligand to probe the brain exposure of long-lasting opioids in humans. This manuscript describes [ 11 C]LAAM synthesis and its biodistribution in mice. The radiochemical synthetic strategy afforded high radiochemical yield, purity and specific activity, thereby making the synthesis adaptable to automated modules. - Highlights: • Radiochemical synthesis of opioid [ 11 C]l-α-acetylmethadol (LAAM) described for the first time. • High radiochemical yield, purity and specific activity. • Easily reproducible and adaptable synthesis to any C-11 automated modules. • [ 11 C]LAAM utility as a PET radiopharmaceutical for assessing brain penetration

Radiochemical separation of actinides for their determination in environmental samples and waste products

Energy Technology Data Exchange (ETDEWEB)

Gleisberg, B [Nuclear Engineering and Analytics Rossendorf, Inc. (VKTA), Dresden (Germany)

1997-03-01

The determination of low level activities of actinides in environmental samples and waste products makes high demands on radiochemical separation methods. Artificial and natural actinides were analyzed in samples form the surrounding areas of NPP and of uranium mines, incorporation samples, solutions containing radioactive fuel, solutions and solids resutling from the process, and in wastes. The activities are measured by {alpha}-spectrometry and {gamma}-spectrometry. (DG)

Radiochemical determination of 210 Pb and 226Ra in petroleum sludges and scales

International Nuclear Information System (INIS)

Araujo, Andressa Arruda de

2005-01-01

The oil extraction and production, both onshore and offshore, can generate different types of residues, such as sludge, that is deposited in the water/oil separators, valves and storage tanks and scales, which form i the inner surface of ducts and equipment. Analyses already carried out through gamma spectrometry indicated the existence of high radioisotope concentration. However, radionuclides emitting low-energy gamma-rays, such as 210 Pb, are hardly detected by that technique. Consequently, there is a need to test alternative techniques to determine this and other radionuclides from the 238 U series. This work, therefore, focuses on the radiochemical determination of the concentration of 210 Pb, and 226 Ra in samples of sludge and scale from the oil processing stations of the UN-SEAL, a PETROBRAS unit responsible for the exploration and production of petroleum in Sergipe and Alagoas. The sludge and scale samples went through a preliminary process of extraction of oil, in order to separate the solid phase, where the largest fraction of the radioactivity is concentrated. After oil removal, the samples were digested using alkaline fusion as an option for dissolution. Finally, their activity concentration was determined for the samples of sludge and scales, using and alternative radiochemical method, which is based on ionic exchange. The activity concentration found for 210 Pb varied from 1,14 to 507,3 kBq kg -1 . The values for 226 Ra were higher, varying from 4,36 to 3.445 kBq kg -1 . The results for 226 Ra were then compared with the ones found for the same samples of sludge and scales using gamma spectrometry. The results of the comparison confirm the efficiency of the methodology used int hi work, that is, radiochemical determination by means of ionic exchange. (author)

Radiochemical separation and their application to neutron activation analysis technique

International Nuclear Information System (INIS)

Turel, Z.R.

2013-01-01

The present paper discusses the development of some new, rapid and selective method for the radiochemical separation and estimation of elements such as, Co(II) 2-3 , Ir(III) 4 , Au(III) 5 , Pt(IV), Pd(II), Os(IV) 6 , Cu(II), Ag(I), Mo(VI), Ni(II), Zn(II), Cd(II), Hg(II), Cs(I), Sb(III), La(III), Sc(III) etc. using various reagents. Various parameters such as pH, time of equilibrium, effect of anions and cations, effect of reagent etc. has been determined employing tracers of the elements under consideration and will be discussed. The method is made highly selective by the use of appropriate masking agent. The stoichiometry of metal reagent is determined by the substoichiometric method. Some examples of multielemental radiochemical separation methods thus developed which have been applied in determining the elements by radiochemical thermal neutron activation analysis will be presented and discussed. The implications of the results on the reference system will also be accounted. Statistical evaluation with reference to accuracy, precision and sensitivity will also be presented

Improving Orientation Outcomes: Implementation of Phased Orientation Process in an Intermediate Special Care Nursery.

Science.gov (United States)

Rivera, Emily K; Shedenhelm, Heidi J; Gibbs, Ardyce L

2015-01-01

In response to changing needs of registered nurse orientees, the staff education committee in the Intermediate Special Care Nursery has implemented a phased orientation process. This phased process includes a mentoring experience postorientation to support a new nurse through the first year of employment. Since implementing the phased orientation process in the Intermediate Special Care Nursery, orientee satisfaction and preparation to practice have increased, and length of orientation has decreased.

Radiolabeling, quality control and radiochemical purity assessment of 99mTc-HYNIC-TOC

International Nuclear Information System (INIS)

Melero, Laura T.U.H.; Araujo, Elaine B.; Mengatti, Jair

2009-01-01

Somatostatine receptors are widely expressed by several tumors, especially of the neuroendocrine origin. In vivo images of these tumors using radiolabeled somatostatine analogues became a useful clinical tool in oncology. The aim of this work was the radiolabeling of the somatostatine analogue HYNIC-TOC with 99mTc as well as the evaluation of the radiochemical stability and quality control of labeled complex. 99mTc-HYNIC-TOC was produced by labeling conditions using 20 μg of peptide, 20 mg of tricine and 10 mg of EDDA as coligands, 1110 MBq of 99mTc (99Mo-99mTc IPEN-TEC generator) and 15 μg of SnCl 2 .2H 2 O. The reaction proceeds for 10 minutes at boiling water bath. Radiochemical purity of labeled preparation was evaluated by different chromatographic systems: ITLC-SG in methanol:ammonium acetate (1:1); TLC-SG in sodium citrate buffer 0.1 N pH 5.0 and methylethylketone, and HPLC employing column C-18, 5 μm, 4.6 mm x 250 mm, UV (220 nm), radioactivity detectors, 1 mL/minute flow of acetonitrile and trifluoroacetic acid solution 0.1 %. Labeled compound has been found radiochemically stable for 5 hours and radiochemical purity was higher than 90 %. The thin layer chromatographic systems enabled the separation of radiochemical species presented in the labeled mixture as well as HPLC system. The labeling procedure studied resulted in high radiochemical yield and easy preparation. Future works include the preparation of a lyophilized reagent to make feasible the preparation of 99mTc-HYNIC-TOC at nuclear medicine services in order to study the clinical potential of the radiopharmaceutical in diagnostic and staging of neuroendocrine tumors. (author)

Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

International Nuclear Information System (INIS)

Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

2015-01-01

We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

Miniaturized chromatographic radiochemical procedure for 131I - MIBG

International Nuclear Information System (INIS)

Barboza, M.F. de; Pereira, N.S. de; Colturato, M.T.; Silva, C.P.G. da.

1989-12-01

Different solvents were used in paper chromatographic methods to obtain the best system in routine radiochemical control for 131 I-MIBG produced at IPEN-CNEN/SP. The dates were compared with those obtained with eletrophoresis method in buffer acetate, pH=4.5, 350V, during 40 minutes. The stability of the labeled compound store under 4 0 C was studied during 15 days. Miniaturized chromatographic procedures were established using Whatman 3MM (8x1cm) and n-butanol-:acetic acid: water (S:2:1) as a solvent. the Rf values were: 0.3 (I - ) and 1.0 (MIBG). The radiochemical purity was 99.3 and 99.2% (first day) obtained with eletrophoresis and miniaturized chromatographic procedures, respectively and, 84.7% after 15 days of its preparation. It is a rapid, practical and reproductive method. (author) [pt

Synthesis of N-[methyl-11C]hydromorphone by using multivariate strategies for optimization of radiochemical yields

International Nuclear Information System (INIS)

Rimland, Annika; Bergson, Goeran; Obenius, Ulf; Sjoeberg, Stefan; Langstroem, Bengt

1987-01-01

The synthesis of N-[methyl- 11 C]hydromorphone has been performed by using [ 11 C]methyl iodide and desmethyl hydromorphone in a mixture of dimethylsulphoxide and dimethylformamide as solvent. Optimization of the radiochemical yield by varying the reaction conditions was performed by using multivariate strategies. The labelled hydromorphone was obtained in 72% radiochemical yield in the alkylation reaction with [ 11 C]-methyl iodide, counted from the end of the [ 11 C]methyl iodide synthesis. N-[Methyl- 11 C]hydromorphone was obtained as a ready injectable pharmaceutical solution with a total synthesis time of 40 min and in a 10% total radiochemical yield, with a radiochemical purity > 99.5%, according to HPLC analysis. (author)

Feasibility of large volume casting cementation process for intermediate level radioactive waste

International Nuclear Information System (INIS)

Chen Zhuying; Chen Baisong; Zeng Jishu; Yu Chengze

1988-01-01

The recent tendency of radioactive waste treatment and disposal both in China and abroad is reviewed. The feasibility of the large volume casting cementation process for treating and disposing the intermediate level radioactive waste from spent fuel reprocessing plant in shallow land is assessed on the basis of the analyses of the experimental results (such as formulation study, solidified radioactive waste properties measurement ect.). It can be concluded large volume casting cementation process is a promising, safe and economic process. It is feasible to dispose the intermediate level radioactive waste from reprocessing plant it the disposal site chosen has resonable geological and geographical conditions and some additional effective protection means are taken

A radiochemical assay for biotin in biological materials

International Nuclear Information System (INIS)

Hood, R.L.

1975-01-01

A radiochemical assay for biotin is described. The assay was sensitive to one nanogram and simple enough for routine biotin analyses. The assay yielded results which were comparable to those obtained from a microbiological assay using Lactobacillus plantarum. (author)

Process Writing in the Intermediate Grades: Magical Panacea or Oversold Cliche?

Science.gov (United States)

Balajthy, Ernest

Noting that the principles of writing process instruction typically offered to elementary teachers are less readily adaptable to intermediate classrooms emphasizing content area learning rather than basic skills, this paper explores two key themes important to the successful implementation of writing process instruction: (1) teachers' needs to…

Application of radiochemical determination methods in cleanability research of building materials

International Nuclear Information System (INIS)

Maeaettae, Jenni; Kymaelaeinen, Hanna-Riitta; Sjoeberg, Anna-Maija

2011-01-01

During recent years increasing effort has been made to modify surface properties with easy-to-clean or self-cleaning characteristics, and concomitantly there is a need to be able to quantify cleanability. Methodology is a complex issue, including aspects of selection and characterization of the surface materials, the soiling materials (contaminants), soiling and cleaning methods, and the detection methods. Different biological, chemical, physical and visual methods have been included in studies of surface cleanability. One challenge has been to obtain quantitative information about soiling. The radiochemical methods, gamma spectrometry (NaI(Tl)-crystal) and liquid scintillation counting, have been shown to be suitable for evaluating cleanability of different surface materials and different soiling material types, providing quantitative information about the amount of soiling material both on and beneath the surface. Due to the different labelled soiling components, the interaction of the surface with different soiling material types can be evaluated. Radiochemical methods have unique benefits particularly for examining porous materials and surfaces. However, they are suitable only for highly controlled studies because of the hazards. Different features and details of radiochemical methods are discussed with the view to aid planning of future cleanability studies. - Highlights: → Radiochemical methods can be used for cleanability studies. → These methods give quantitative information about the amount of soiling material. → These methods are suitable particularly for examining porous materials. → These methods are suitable for highly controlled studies because of the hazards.

Low and intermediate level radioactive waste processing in plasma reactor

International Nuclear Information System (INIS)

Sauchyn, V.; Khvedchyn, I.; Van Oost, G.

2013-01-01

Methods of low and intermediate level radioactive waste processing comprise: cementation, bituminization, curing in polymer matrices, combustion and pyrolysis. All these methods are limited in their application in the field of chemical, morphological, and aggregate composition of material to be processed. The thermal plasma method is one of the universal methods of RAW processing. The use of electric-arc plasma with mean temperatures 2000 - 8000 K can effectively carry out the destruction of organic compounds into atoms and ions with very high speeds and high degree of conversion. Destruction of complex substances without oxygen leads to a decrease of the volume of exhaust gases and dimension of gas cleaning system. This paper presents the plasma reactor for thermal processing of low and intermediate level radioactive waste of mixed morphology. The equipment realizes plasma-pyrolytic conversion of wastes and results in a conditioned product in a single stage. As a result, the volume of conditioned waste is significantly reduced (more than 10 times). Waste is converted into an environmentally friendly form that suits long-term storage. The leaching rate of macro-components from the vitrified compound is less than 1.10 -7 g/(cm 2 .day). (authors)

Radiochemicals in biomedical research

International Nuclear Information System (INIS)

Evans, E.A.; Oldham, K.G.

1988-01-01

This volume describes the role of radiochemicals in biomedical research, as tracers in the development of new drugs, their interaction and function with receptor proteins, with the kinetics of binding of hormone - receptor interactions, and their use in cancer research and clinical oncology. The book also aims to identify future trends in this research, the main objective of which is to provide information leading to improvements in the quality of life, and to give readers a basic understanding of the development of new drugs, how they function in relation to receptor proteins and lead to a better understanding of the diagnosis and treatment of cancers. (author)

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

Radiolabeling, quality control and radiochemical purity assessment of {sup 99m}Tc-HYNIC-TOC

Energy Technology Data Exchange (ETDEWEB)

Melero, Laura T.U.H.; Araujo, Elaine B.; Mengatti, Jair [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2009-07-01

Somatostatine receptors are widely expressed by several tumors, especially of the neuroendocrine origin. In vivo images of these tumors using radiolabeled somatostatine analogues became a useful clinical tool in oncology. The aim of this work was the radiolabeling of the somatostatine analogue HYNIC-TOC with 99mTc as well as the evaluation of the radiochemical stability and quality control of labeled complex. 99mTc-HYNIC-TOC was produced by labeling conditions using 20 {mu}g of peptide, 20 mg of tricine and 10 mg of EDDA as coligands, 1110 MBq of 99mTc (99Mo-99mTc IPEN-TEC generator) and 15 {mu}g of SnCl{sub 2}.2H{sub 2}O. The reaction proceeds for 10 minutes at boiling water bath. Radiochemical purity of labeled preparation was evaluated by different chromatographic systems: ITLC-SG in methanol:ammonium acetate (1:1); TLC-SG in sodium citrate buffer 0.1 N pH 5.0 and methylethylketone, and HPLC employing column C-18, 5 {mu}m, 4.6 mm x 250 mm, UV (220 nm), radioactivity detectors, 1 mL/minute flow of acetonitrile and trifluoroacetic acid solution 0.1 %. Labeled compound has been found radiochemically stable for 5 hours and radiochemical purity was higher than 90 %. The thin layer chromatographic systems enabled the separation of radiochemical species presented in the labeled mixture as well as HPLC system. The labeling procedure studied resulted in high radiochemical yield and easy preparation. Future works include the preparation of a lyophilized reagent to make feasible the preparation of 99mTc-HYNIC-TOC at nuclear medicine services in order to study the clinical potential of the radiopharmaceutical in diagnostic and staging of neuroendocrine tumors. (author)

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.

Current studies of biological materials using instrumental and radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Fardy, J.J.; McOrist, G.D.; Farrar, Y.J.

1985-01-01

Instrumental neutron activation analysis still remains the preferred option when analysing the trace element distribution in a wide rage of materials by neutron activation analysis. However, when lower limits of detection are required or major interferences reduce the effectiveness of this technique, radiochemical neutron activation analysis is applied. This paper examines the current use of both methods and the development of rapid radiochemical techniques for analysis of the biological materials, hair, cow's milk, human's milk, milk powder, blood and blood serum

Northern Marshall Islands Radiological Survey: a quality-control program for a radiochemical analyses

International Nuclear Information System (INIS)

Jennings, C.D.; Mount, M.E.

1983-08-01

More than 16,000 radiochemical analyses were performed on about 5400 samples of soils, vegetation, animals, fish, invertebrates, and water to establish amounts of 90 Sr, 137 Cs, 241 Am, and plutonium isotopes in the Northern Marshall Islands. Three laboratories were contracted by Lawrence Livermore National Laboratory to perform the radiochemical analyses: Environmental Analysis Laboratory (EAL), Richmond, California; Eberline Instrument Corporation (EIC), Albuquerque, New Mexico; and Laboratory of Radiation Ecology (LRE), University of Washington, Seattle, Washington. The analytical precision and accuracy were monitored by regularly including duplicate samples and natural matrix standards in each group of about 100 samples analyzed. Based on the duplicates and standards, over 83% of the radiochemical analyses in this survey were acceptable - 97% of the analyses by EAL, 45% of the analyses by EIC, and 98% of the analyses by LRE

Procedural and developmental aspects of a multielement automatic radiochemical machine, applied to neutron irradiated biomedical samples

International Nuclear Information System (INIS)

Iyengar, G.V.

1976-06-01

This report is intended to serve as a practical guide, elaborately describing the working details and some developmental work connected with an automatic multielement radiochemical machine based on thermal neutron activation analysis using ion exchange and partition chromatography. Some of the practical aspects and personal observations after much experience with this versatile multielement method, applied to investigate the elemental composition of different biomedical matrices, are summarized. Standard reference materials are analyzed, and the data are presented with a set of gamma-spectra obtained before and after chemical separation into convenient groups suitable for gamma spectroscopy. The samples analyzed included various human and animal tissues, body fluids, IAEA biological standard reference materials, and samples from the WHO/IAEA project on 'Trace elements in relation to cardiovascular diseases'. Simplified modifications of the radiochemical processing, suitable for fast and routine analysis of clinical samples have also been discussed. (orig.) [de

On the methodology of radiochemical neutron activation analysis of noble metals

International Nuclear Information System (INIS)

Chai, C.F.; Ma, S.L.; Mao, X.Y.; Liao, K.N.; Liu, W.C.

1986-01-01

Two different radiochemical procedures were developed: chelate ion resin exchange and amine solvent extraction. Two kinds of new Chinese chelate resins (NANKAI-3926 and BEI-5) and a new long-chain primary amine N 1923 were compared with Srafion NMRR and the tertiary amine N 235 in absorption performance of noble metals, respectively. Influences of various experimental conditions, e.g. sample digestion, acidity, equilibrium time, as well as elution of noble metals, on analytical sensitivity and chemical yield were discussed. Combining with neutron activation, the radiochemical separation procedures developed were used to determine the noble metal contents in the geological samples from Permina/Triassic boundary in South China. (author)

Scientific and technical conference. Problems and horizons of development of chemical and radiochemical control in nuclear energetics. Collection of summaries of reports

International Nuclear Information System (INIS)

2001-01-01

During scientific and technical conference on problems of development of chemical and radiochemical control in nuclear energetics following themes were considered: the problems of methodological and instrumental assurance of chemical and radiochemical control at working nuclear power plants and nuclear energetic units; modern conceptions of automation systems construction of chemical and radiochemical control on the basis of intellectual measuring channels; the ways of decision of generally system problems of organization and management of chemical and radiochemical control using computed technologies; the problems of certification of chemical and radiochemical methods of measuring in nuclear energetics [ru

Radiochemical analysis of the Bikini ashes

Energy Technology Data Exchange (ETDEWEB)

Ishibashi, M; Shigematsu, T; Ishida, T

1954-01-01

The following nuclides were detected in the Bikini ashes by radiochemical procedures: /sup 45/Ca, /sup 89/Sr, /sup 91/Y, /sup 95/Zr, /sup 103/Ru, /sup 144/Pr, and /sup 237/U. The ion-exchange method was used for analysis of contaminated rain water which fell on the Kyoto area on May 16, 1954 from which the presence of /sup 89/Sr, /sup 95/Zr, and /sup 140/Ba, was detected. Rare earths seemed also to be present.

Handling of Ammonium Nitrate Mother-Liquid Radiochemical Production - 13089

International Nuclear Information System (INIS)

Zherebtsov, Alexander; Dvoeglazov, Konstantine; Volk, Vladimir; Zagumenov, Vladimir; Zverev, Dmitriy; Tinin, Vasiliy; Kozyrev, Anatoly; Shamin, Dladimir; Tvilenev, Konstantin

2013-01-01

The aim of the work is to develop a basic technology of decomposition of ammonium nitrate stock solutions produced in radiochemical enterprises engaged in the reprocessing of irradiated nuclear fuel and fabrication of fresh fuel. It was necessary to work out how to conduct a one-step thermal decomposition of ammonium nitrate, select and test the catalysts for this process and to prepare proposals for recycling condensation. Necessary accessories were added to a laboratory equipment installation decomposition of ammonium nitrate. It is tested several types of reducing agents and two types of catalyst to neutralize the nitrogen oxides. It is conducted testing of modes of the process to produce condensation, suitable for use in the conversion of a new technological scheme of production. It is studied the structure of the catalysts before and after their use in a laboratory setting. It is tested the selected catalyst in the optimal range for 48 hours of continuous operation. (authors)

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)

Radiochemical problems of radiation chemical synthesis in n, γ-field of nuclear reactor

International Nuclear Information System (INIS)

Mironov, V.P.; Frejdus, N.V.; Bugaenko, L.T.; Kalyazin, E.P.; Petryaev, E.P.

1981-01-01

A wide applicability of products of radiation chemical synthesis (RCS), using n, γ-irradiation, is limited by possible contamination of the latter with long-lived radioactive isotopes of chemical elements included in the composition of the reagent and compounds syntesized (chemically non-separable radionuclides - CNR). A technique of the determination of the limit accumulation CNR on the basis of radiation chemical parameters of the synthesis (radiation-chemical yield, the dose rate absorbed, singleness of purpose of RCS etc.) and radiochemical parameters of formation and accumulation of CNR (radiochemical yields of CNR in the products of radiolysis, neutron fluence, the reagent purity etc.) is suggested. The radiochemical evaluation of CNR accumulation (tritium and carbon-14), formed at the expense of activation with neutrons of chemical elements of water and organic substances, consisting of hydrogen, carbon and oxygen has shown that at relatively low yields of final products (> or approximately 3 molecules/100 eV) no accumulation of radionuclides in concentrations reaching the average admissible concentration takes place [ru

Minicomputer system for radiochemical analysis by coincidence spectrometry

International Nuclear Information System (INIS)

Brauer, F.P.; Fager, J.E.

1979-01-01

Minicomputer-based coincidence analysis methods have been developed for use in performing radiochemical analysis by high-resolution x- and gamma-ray coincidence spectrometry. This paper describes the data-acquisition and analysis methods develolped for qualitative and quantitative analyses of coincidence spectrometric data. Data-acquisition capabilities include both direct multiparameter pulse-height analysis and buffered list-mode acquisition

Slifers revisited: a method for determining yields independent of radiochemical measurements

International Nuclear Information System (INIS)

Rambo, J.T.

1976-01-01

It would be very desirable if an independent method other than radiochemical measurement were available to determine the yields of low-yield events in the alluviums and tuffs of areas 2, 9, and 10 at the Nevada Test Site. The successful application of slifers to the measurement of yields from high-yield events suggests that under some conditions they may also be usable with low-yield events. This view is supported by the evidence discussed here, which is based on direct experience with slifer yield measurements for low-yield events in porous media. Suggested methods for improving slifer yield determinations and a method for determining yields independent of radiochemical measurements are offered

Rapid radiochemical separation of short-lived radionuclides in neutron-activated samples

International Nuclear Information System (INIS)

Fardy, J.

1985-11-01

Radiochemical separation procedures based on the removal of metal ions by columns of C 18 -bonded silica gel after selective complexation are examined and the simplicity of the method demonstrated by its application to determination of Mn, Cu and Zn in neutron-activated biological material from the following solutions (pH 0-10, sulphate concentration 0,18M and 1,44M SO 4 ): 8-hydroxyquinoline (oxine), ammonium pyrrolidinedithiocarbamate (APDC), cupferron (CUP), 1-(2-pyridylazo)-2-naphthol (PAN), 1-(2'-thiazolylazo)-2-naphthol (TAN), 4-(2-pyridylazo) resorcinol (PAR), diethylammonium diethyldithiocarbamate (DDC), potassium ethyl xanthate (PEX), acetylacetone (AcAc) or thenoyltrifluoracetone (TTA). The method is rapid and reliable and readily adaptable in all radiochemical laboratories

Methods and Production of Cementation Materials for Immobilisation into Waste Form. Research of Cementation Processes for Specific Liquid Radioactive Waste Streams of Radiochemical Plants

International Nuclear Information System (INIS)

Sukhanov, L.P.

2013-01-01

In the near future Russian Federation is planning to use industrial cementation facilities at two radiochemical combines - PA 'Mayak' and Mountain Chemical Combine. Scope of the research within the IAEA CRP contact No. 14176 included the development of cementation processes for specfic liquid radioactive waste streams that are present in these enterprisers. The research on cementation of liquid waste from spent nuclear fuel reprocessing at PA 'Mayak' allowed obtaining experimental data characterizing the technological process and basic characteristics of the produced cement compounds (e.g. mechanical strength, water resistance, frost resistance, flowability, etc.) immobilizing different streams of waste (e.g. hydrated-salt sludges, filter material pulps, mixture of hydrated salt slurries and filter material pulps, tritium liquid waste). Determined optimum technological parameters will allow industrial scale production of cement compound with required quality and higher flowability that is necessary for providing uniform filling of compartments of storage facilities at these sites. The research has been also carried out for the development of cementation technology for immobilization of pulps from storage tanks of Mountain Chemical Combine radiochemical plant. Cementation of such pulps is a difficult technological task because pulps are of complex chemical composition (e.g. hydroxides of manganese, iron, nickel, etc., as well as silicon oxide) and a relatively high activity. The research of cementation process selection for these pulps included studies of the impact of sorbing additive type and content on cement compounds leachability, flowability, impact of cement compound age to its mechanical strength, heat generation of cement compounds and others. The research results obtained allowed testing of cementation facility with a pulse type mixer on the full-scale. Use of such mixer for pulp cementation makes possible to prepare a homogeneous cement compound with the

The material control and accounting system model development in the Radiochemical plant of Siberian Chemical Combine (SChC)

International Nuclear Information System (INIS)

Kozyrev, A.S.; Purygin, V.Ya.; Skuratov, V.A.; Lapotkov, A.A.

1999-01-01

The nuclear material (NM) control and accounting computerized system is designed to automatically account NM reception, movement and storage at the Radiochemical Plant. The objective of this system development is to provide a constant surveillance over the process material movement, to improve their accountability and administrative work, to upgrade the plant protection against possible NM thefts, stealing and diversion, to rule out any casual errors of operators, to improve the timeliness and significance (reliability) of information about nuclear materials. The NM control and accounting system at the Radiochemical Plant should be based on the computerized network. It must keep track of all the material movements in each Material Balance Areas: material receipt from other plant; material local movement within the plant; material shipment to other plants; generation of required documents about NM movements and its accounting [ru

Abyssal sediment erosion from the Central Indian Basin: Evidence from radiochemical and radiolarian studies

Digital Repository Service at National Institute of Oceanography (India)

Banakar, V.K.; Gupta, S.M.; Padmavati, V.K.

) 167-173 167 Elsevier Science Publishers B.V., Amsterdam Letter Section Abyssal sediment erosion in the Central Indian Basin: Evidence from radiochemical and radiolarian studies V.K. Banakar, S.M. Gupta and V.K. Padmavathi National Institute... of Oceanography, Dona-Paula, Goa-403 004, India (Revision accepted September 17, 1990) ABSTRACT Banakar, V.K., Gupta, S.M. and Padmavathi, V.K., 1991. Abyssal sediment erosion from the Central Indian Basin: Evi- dence from radiochemical and radiolarian studies...

ESOL facility for the generation and radiochemical separation of short half-life fission products

International Nuclear Information System (INIS)

Gehrke, R.J.; Meikrantz, D.H.; Baker, J.D.; Anderl, R.A.; Novick, V.J.; Greenwood, R.C.

1988-01-01

A facility has been developed at the Idaho National Engineering Laboratory (INEL) for the generation and rapid radiochemical separation of short half-life mixed fission products. This facility, referred to as the Idaho Elemental Separation On Line (ESOL), consists of electro-plated sources of spontaneously fissioning 252 Cf with a helium jet transport arrangement to continuously deliver short half-life, mixed fission products to the radiochemistry laboratory for rapid, computer controlled, radiochemical separations. 18 refs., 13 figs

14th radiochemical conference. Booklet of abstracts

International Nuclear Information System (INIS)

2002-03-01

The contributions dealt with the following topics: Radionuclides in the environment, radioecology; Nuclear analytical methods; Chemistry of actinide and trans-actinide elements; Ionizing radiation in science, technology, and arts and cultural heritage preservation; Production and application of radionuclides; Separation methods, speciation; Chemistry of nuclear fuel cycle, radiochemical problems in nuclear waste management; and Nuclear methods in medicine, radiopharmaceuticals, and radiodiagnostics, labelled compounds. Of the verbal and poster presentation, 192 have been input to INIS. (P.A.)

Intermediate care: for better or worse? Process evaluation of an intermediate care model between a university hospital and a residential home

Directory of Open Access Journals (Sweden)

Janmaat Tonnie ACM

2005-05-01

Full Text Available Abstract Background Intermediate care was developed in order to bridge acute, primary and social care, primarily for elderly persons with complex care needs. Such bridging initiatives are intended to reduce hospital stays and improve continuity of care. Although many models assume positive effects, it is often ambiguous what the benefits are and whether they can be transferred to other settings. This is due to the heterogeneity of intermediate care models and the variety of collaborating partners that set up such models. Quantitative evaluation captures only a limited series of generic structure, process and outcome parameters. More detailed information is needed to assess the dynamics of intermediate care delivery, and to find ways to improve the quality of care. Against this background, the functioning of a low intensity early discharge model of intermediate care set up in a residential home for patients released from an Amsterdam university hospital has been evaluated. The aim of this study was to produce knowledge for management to improve quality of care, and to provide more generalisable insights into the accumulated impact of such a model. Methods A process evaluation was carried out using quantitative and qualitative methods. Registration forms and patient questionnaires were used to quantify the patient population in the model. Statistical analysis encompassed T-tests and chi-squared test to assess significance. Semi-structured interviews were conducted with 21 staff members representing all disciplines working with the model. Interviews were transcribed and analysed using both 'open' and 'framework' approaches. Results Despite high expectations, there were significant problems. A heterogeneous patient population, a relatively unqualified staff and cultural differences between both collaborating partners impeded implementation and had an impact on the functioning of the model. Conclusion We concluded that setting up a low intensity

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

Radiochemical procedures for determination of selected members of the uranium and thorium series

International Nuclear Information System (INIS)

Smithson, G.L.

1979-01-01

The radiochemical procedures contained in this manual are adaptations of those developed and published by many radiochemists. In many cases the identity of the originator is not clear and usually modifications in the original procedure have been made by subsequent workers. Nearly all of the basic radiochemical techniques and separations in use today were developed during the Manhattan Project and can be found in U.S.A.E.C. reports published from 1945 to 1953. This manual contains methods for the determination of Pb-210, Po-210; Ra-226, Ra-228, Th-228, Th-230 and Th-232. (auth)

Current issues in the management of low- and intermediate-level radioactive wastes from Ontario Hydro's CANDU reactors

International Nuclear Information System (INIS)

Krasznai, J.P.; Vaughan, B.R.; Williamson, A.S.

1990-01-01

Nuclear generating stations (NGSs) in Canada are operated by utilities in Ontario, Quebec, and New Brunswick. Ontario Hydro, with a committed nuclear program of 13,600 MW(electric) is the major producer of CANDU pressurized heavy-water reactor (PHWR) low- and intermediate-level radioactive wastes. All radioactive wastes with the exception of irradiated fuel are processed and retrievably stored at a centralized facility at the Bruce Nuclear Power Development site. Solid-waste classifications and annual production levels are given. Solid-waste management practices at the site as well as the physical, chemical, and radiochemical characteristics of the wastes are well documented. The paper summarizes types, current inventory, and estimated annual production rate of liquid waste. Operation of the tritium recovery facility at Darlington NGS, which removes tritium from heavy water and produces tritium gas in the process, gives rise to secondary streams of tritiated solid and liquid wastes, which will receive special treatment and packaging. In addition to the treatment of radioactive liquid wastes, there are a number of other important issues in low- and intermediate-level radioactive waste management that Ontario Hydro will be addressing over the next few years. The most pressing of these is the reduction of radioactive wastes through in-station material control, employee awareness, and improved waste characterization and segregation programs. Since Ontario Hydro intends to store retrievable wastes for > 50 yr, it is necessary to determine the behavior of wastes under long-term storage conditions

Radiochemical techniques for determining some naturally occurring radionuclides in marine environmental materials

Energy Technology Data Exchange (ETDEWEB)

Baker, C W [Ministry of Agriculture, Fisheries and Food, Lowestoft (UK). Fisheries Lab.

1984-06-15

The determination of some of the naturally-occurring, alpha-emitting radionuclides in marine environmental materials, is of interest for several reasons. Radium and radon nuclides are potentially useful as oceanographic tracers. Lead and thorium nuclides may be used to study sedimentation rates, mixing processes and bioturbation in sediments. Radium and polonium nuclides are incorporated into food chains and the data may provide a perspective against which to assess the significance, for marine organisms, of exposure to radiation in a marine radioactive waste disposal situation. This paper discusses the manner in which samples are taken, and the radiochemical methods which have been employed to measure the nuclides, together with some data produced.

Intermediate Fragment

DEFF Research Database (Denmark)

Kruse Aagaard, Anders

2015-01-01

This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

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.

The Northern Marshall Islands radiological survey: A quality control program for radiochemical and gamma spectroscopy analysis

International Nuclear Information System (INIS)

Kehl, S.R.; Mount, M.E.; Robison, W.L.

1995-09-01

From 1979 to 1989, approximately 25,000 Post Northern Marshall Islands Radiological Survey (PNMIRS) samples were collected, and over 71,400 radiochemical and gamma spectroscopy analyses were performed to establish the concentration of 90 Sr, 137 Cs, 241 Am, and plutonium isotopes in soil, vegetation, fish, and animals in the Northern Marshall Islands. While the Low Level Gamma Counting Facility (B379) in the Health and Ecological Assessment (HEA) division accounted for over 80% of all gamma spectroscopy analyses, approximately 4889 radiochemical and 5437 gamma spectroscopy analyses were performed on 4784 samples of soil, vegetation, terrestrial animal, and marine organisms by outside laboratories. Four laboratories were used by Lawrence Livermore National Laboratory (LLNL) to perform the radiochemical analyses: Thermo Analytical Norcal, Richmond, California (TMA); Nuclear Energy Services, North Carolina State University (NCSU); Laboratory of Radiation Ecology, University of Washington (LRE); and Health and Ecological Assessment (HEA) division, LLNL, Livermore, California. Additionally, LRE and NCSU were used to perform gamma spectroscopy analyses. The analytical precision and accuracy were monitored by including blind duplicates and natural matrix standards in each group of samples analyzed. On the basis of reported analytical values for duplicates and standards, 88% of the gamma and 87% of the radiochemical analyses in this survey were accepted. By laboratory, 93% of the radiochemical analyses by TMA; 88% of the gamma-ray spectrometry and 100% of the radiochemistry analyses by NCSU; 89% of the gamma spectroscopy and 87% of the radiochemistry analyses by LRE; and 90% of the radiochemistry analyses performed by HEA's radiochemistry department were accepted

Electrochemistry as a basis for radiochemical generator systems

International Nuclear Information System (INIS)

Bentley, G.E.; Steinkruger, F.J.; Wanek, P.M.

1984-01-01

Ion exchange and solvent extraction techniques have been used extensively as the basis for radiochemical generators exploiting the differences in absorption behavior between the parent nuclide and its useful daughter nuclide. Many parent/daughter pairs of nuclides have sufficiently different polarographic half wave potentials so that their electrochemical behavior may be exploited for rapid separation of the daughter from the parent with minimal contamination of the product with the parent isotope

Investigations of radiochemical methods for the platinum group metals for NAA

International Nuclear Information System (INIS)

Tredoux, M.

A radiochemical procedure for the determination of the platinum group metals and gold is outlined in this report. The sample is irradiated, treated with acids and passed through anion-exchange columns before being determined by gamma spectrometry

Rapid, radiochemical-ligand binding assay for methotrexate

International Nuclear Information System (INIS)

Caston, J.D.

1976-01-01

A radiochemical ligand binding assay for methotrexate is provided. A binder factor comprising a partially purified dihydrofolic acid reductase preparation is employed. The binder factor is conveniently prepared by homogenizing a factor containing animal organ such as liver, and extracting with isotonic saline and ammonium sulfate. A binder cofactor, NADPH 2 , is also employed in the binding reaction. The procedure contemplates both direct and sequential assay techniques, and it is not interfered with by vast excesses of many natural folate derivatives. 12 claims, 6 drawing figures

Experimental study on intermediate level radioactive waste processing

International Nuclear Information System (INIS)

Nagakura, Tadashi; Abe, Hirotoshi; Okazawa, Takao; Hattori, Seiichi; Maki, Yasuro

1977-01-01

In the disposal of intermediate level radioactive wastes, multilayer package will be adopted. The multilayer package consists of cement-solidified waste and a container such as a drum - can with concrete liner or a concrete container. So, on the waste to be cement-solidified in such container, experimental study was carried out as follows. (1) Cement-solidification method. (2) Mechanical behaviour of cement-solidified waste. The mechanical behaviour of the containers was studied by the finite element method and experiment, and the function of pressure-balancing valves was also studied. The following data on processing intermediate level radioactive wastes were obtained. (1) In the case of cement-solidified waste, the data to select the suitable solidifying material and the standard mixing proportion were determined. (2) The basic data concerning the uniaxial compressive strength of cement-solidified waste, the mechanical behaviour of cement-solidified waste packed in a drum under high hydrostatic pressure, the shock response of cement-solidified waste at the time of falling and so on were obtained. (3) The pressure-balancing valves worked at about 0.5 Kg/cm 2 pressure difference inside and outside a container, and the deformation of a drum cover was 10 to 13 mm. In case of the pressure difference less than 0,5 Kg/cm 2 , the valves shut, and water flow did occur. (auth.)

RADIOCHEMICAL YIELDS OF GRAFT POLYMERIZATION REACTIONS OF CELLULOSE

Energy Technology Data Exchange (ETDEWEB)

Arthur, Jr, J C; Blouin, F A

1963-12-15

The preparation of radioinduced graft polymers of cotton cellulose, while retaining the fibrous nature and high molecular weight of the cellulose, depended primarily on the radiochemical yields of cellulose reactions and of graft polymerization reactions. Yields of the initial major molecular changes in cellulosic polymer indicated that, in the case of scission of the molecule and carboxyl group formation, chain reactions were not initiated by radiation; however, in the case of carbonyl group formation chain reactions were initiated but quickly terminated. Generally, experimental procedures, used in graft polymerization reactions, were: simultaneous irradiation reactions, that is, application of monomers or solutions of monomers to cellulose or chemically modified celluloses, then irradiation; and post-irradiation reactions, that is, irradiation of cellulose or chemically modified celluloses, then after removal from the field of radiation, contacting the irradiated cellulose with monomer. Some of the most important factors influencing the radiochemical yields of graft polymerization reactions, of styrene and acrylonitrile onto cellulose were: concentration of monomer in treating solution; solvent; ratio of monomer solution to cellulose; prior chemical modification of cellulose; and absence of oxygen, particularly in post-irradiation reactions. Experimental data are presented, and the direct and indirect effects of Co/sup 60/ gamma radiation on these reactions are discussed. (auth)

Intermediate size LWR plant study for process heat plus power. Volume 1. Executive summary

International Nuclear Information System (INIS)

Head, M.A.

1977-01-01

The appropriateness of intermediate sized LWRs is evaluated for application to the process industry and for cogeneration of electric power and process steam. This brief study is directed toward determination of whether such plants show enough promise to warrant more detailed investigation. In light of higher fossil fuel costs, the study shows that intermediate sized, standardized power plants potentially are economically competitive for such industrial applications. A representative intermediate sized operating plant of the BWR/4 design class, the Swiss Muhleberg unit (1000 MWt) has been examined with respect to design, licensability, capacity factor and cost. It has operated at high capacity factor (approximately 75 percent) since turnover 11/72. Its cost when escalated from 1969 to 1976 ($620/kWe) appears competitive. Cost adjustments ($100-$250/kWe) included at this stage for compliance with current licensing and mandatory design requirements are only a preliminary estimate. Further study is recommended to confirm necessary regulatory upgrades for this BWR/4 nuclear plant and to explore specific cost economies through replication leading to a program for construction of a demonstration plant

Standardization of equations for radiochemical calculations

International Nuclear Information System (INIS)

Danahy, R.J.; Dugan, T.A.; Tomlinson, F.K.; Jones, H.W.

1994-01-01

In mid 1993, the Fernald Environmental Restoration Management Corporation (FERMCO), with USEPA approval implemented a project quality assurance plan containing performance-based specifications for radiochemical sample analyses conducted in support of the Fernald site remediation activities. FERMCO's initial approach to acquiring performance-based radioanalytical services was to provide limited guidance regarding equations for computation of the quantities required in each analysis report. It became evident that there was a significant divergence of opinion on how to compute some very basic radiochemical quantities. The use of a standardized set of equations was needed in order to ensure comparability of data from different laboratories. In a remediation project of this magnitude, use of multiple laboratories is a virtual necessity. Consequently comparability of data becomes an extremely important issue. A critical issue in the Remedial Investigation/Feasibility Study (RI/FS) phase of the dean up project is to avoid the occurrence of excessive false positive sample results. Such results could lead to unnecessary clean up and significant additional cost. This paper describes the specific formulas FERMCO is currently using to define such quantities as net sample count rate, sample radionuclide concentration, radiometric tracer and gravimetric carrier recovery. Equations have also been produced to define the uncertainty in each of the above quantities. Equations for the Total Propagated Uncertainty (TPU) and for a sample-specific Minimum Detectable Concentration (MDC) have also been specified. Generalized equations have been reformulated to address the specific conditions which apply to the analysis of FERMCO samples. In particular, FERMCO requires results which have been corrected for the radioactivity in the blank while in other instances, sample results without blank correction are required

A comparison of the radiochemical stability of different iodine-131 labelled metaiodobenzylguanidine formulations for therapeutic use

International Nuclear Information System (INIS)

Wafelman, A.R.; Beijnen, J.H.; Hoefnagel, C.A.; Maes, R.A.A.

1994-01-01

The results of a stability study of three commercially available formulations of [ 131 I]MIBG for therapeutic use and an unstabilized formulation, stored under various conditions, are presented. The stability was followed for 20 days. In all formulations tested, free [ 131 I]iodide, formed by radiolysis, was the most important radiochemical impurity. The pharmaceutical formulation with the largest amount of stabilizer was radiochemically - but not chemically -most stable. (author)

Investigation of quantitative separation of thorium, uranium, neptunium and plutonium from complex radiochemical mixtures

International Nuclear Information System (INIS)

Ushatskij, V.N.; Preobrazhenskaya, L.D.; Kolychev, V.B.; Gugel', E.S.

1979-01-01

Quantitative separation of actinides and their radiochemical purification with the aid of TBP with subsequent separation of thorium and quantitative separation of U, Np and Pu with the aid of D2EHPA have been studied. The method has been developed for quantitative extraction-chromatographic separation and radiochemical purification of nanogram amounts of U, Pu and microgram amounts of Th and Np from complex radiochemical mixtures containing both fragment radioisotopes and non-radioactive macrocomponents ( Fe,Al,Mg,Mn, Na and others). The method calls for application of one-extraction-chromatographic column with TBP and one column with D2EHPA. Thorium is separated at the first stage since it does not form complexes in a chloride solution during washing of the sorption column with 6. OM HCl. Npsup((4)) and Pusup((3)) required for separation are stabilized with the aid of hydrazine and hydroxylamine mixture. The yield of each of the above-cited actinide elements during the complete two-stage separation and at the stage of their separation varies within the range of 98.5-99.3%

Obtention process of phosphorus 32 starting from commercial sulfur and design and construction of the radiochemical separation prototype; Proceso de obtencion de fosforo-32 a partir de azufre comercial y diseno y construccion del prototipo de separacion radioquimica

Energy Technology Data Exchange (ETDEWEB)

Duarte A, C.; Alanis M, J.; Gutierrez R, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2002-07-01

In this work an obtention process of phosphorus 32 ({sup 32} P) in orthophosphoric acid form (H{sub 3}{sup 32}PO{sub 4}) is described starting from commercial sulfur. Also the design and construction of the experimental prototype used in the radiochemical separation and their results in three tests carried out is reported. (Author)

Make to stock and mix to order : choosing intermediate products in the food-processing industry

NARCIS (Netherlands)

Akkerman, Renzo; van der Meer, Dirk; van Donk, Dirk Pieter

2010-01-01

In contrast to discrete manufacturers, food-processing companies can sometimes produce the same end products in different ways: either mix first and then process, or process first and mix later. Moreover, a final product can be mixed from different raw materials or intermediates. That adds a new

Waste treatment at the Radiochemical Engineering Development Center

International Nuclear Information System (INIS)

Brunson, R.R.; Bond, W.D.; Chattin, F.R.; Collins, R.T.; Sullivan, G.R.; Wiles, R.H.

1997-01-01

At the Radiochemical Engineering Development Center (REDC) irradiated targets are processed for the recovery of valuable radioisotopes, principally transuranium nuclides. A system was recently installed for treating the various liquid alkaline waste streams for removal of excess radioactive contaminants at the REDC. Radionuclides that are removed will be stored as solids and thus the future discharge of radionuclides to liquid low level waste tank storage will be greatly reduced. The treatment system is of modular design and is installed in a hot cell (Cubicle 7) in Building 7920 at the REDC where preliminary testing is in progress. The module incorporates the following: (1) a resorcinol-formaldehyde resin column for Cs removal, (2) a cross flow filtration unit for removal of rare earths and actinides as hydroxide, and (3) a waste solidification unit. Process flowsheets for operation of the module, key features of the module design, and its computer-assisted control system are presented. Good operability of the cross flow filter system is mandatory to the successful treatment of REDC wastes. Results of tests to date on the operation of the filter in its slurry collection mode and its slurry washing mode are presented. These tests include the effects of entrained organic solvent in the waste stream feed to the filter

Use of ethyl-α-isonitrosoacetoacetate in the rapid estimation and radiochemical separation of gold

International Nuclear Information System (INIS)

Sawant, A.D.; Haldar, B.C.

1978-01-01

The use of ethyl-α-isonitrosoacetoacetate in the rapid estimation and radiochemical separation of gold is reported. As low as 5.00 mg of Au can be estimated with an accuracy better than 1%. Decontamination values against platinum metals and other metals usually associated with Au are greater than 10 5 . Isotopes and results are tabulated. The time required for radiochemical separation is around 20 min and the recovery of Au is better than 80%. γ-activities were measured with a single channel analyser and NaI(Tl) detector. β-activities were counted on a thin end-window type GM counter. (T.I.)

Radiochemical measurement of mass transport in sodium

International Nuclear Information System (INIS)

Cooper, M.H.; Chiang, S.H.

1976-01-01

Mass transport processes in the sodium coolant of Liquid Metal Fast Breeder Reactors (LMFBRs) are significant in determining rates of corrosion and deposition of radioactive nuclides from the fuel cladding, deposition and cold trapping of fission products from defect or failed fuel, carbon and nitrogen redistribution in the containment materials, and removal of impurities by cold trapping or hot trapping. Mass transport between rotating, concentric cylinders in molten sodium has been investigated using a unique radiochemical method. Long-lived (33 year) cesium-137, dissolved in the sodium, decays radioactively emitting a beta to barium-137m, which decays with a short half-life (2.6 minutes) emitting a gamma. Cesium is weakly adsorbed and remains in solution, while the barium is strongly adsorbed on the stainless steel surfaces. Hence, by measuring the barium-137m activity on movable stainless steel surfaces, one can calculate the mass transport to that surface. Mass transfer coefficients in sodium measured by this method are in agreement with published heat transfer correlations when the effect of the volumetric mass source is taken into account. Hence, heat transfer correlations can be confidently utilized by analogy in estimating mass transfer in liquid-metal systems

Intermediate heat exchanger for HTR process heat application

International Nuclear Information System (INIS)

Crambes, M.

1980-01-01

In the French study on the nuclear gasification of coal, the following options were recommended: Coal hydrogenation, the hydrogen being derived from CH 4 reforming under the effects of HTR heat; the use of an intermediate helium circuit between the nuclear plant and the reforming plant. The purpose of the present paper is to describe the heat exchanger designed to transfer heat from the primary to the intermediate circuit

Distribution of plutonium in organs of extrapulmonary pool in remote periods after the beginning of inhalation in workers of radiochemical plant

International Nuclear Information System (INIS)

Suslova, K.G.; Khokhryakov, V.F.; Tokarskaya, Z.B.; Kudryavtseva, T.I.; Nifatov, A.P.

2000-01-01

Influence of the health state and some dosimetric factors on the distribution of systemic Pu for workers of radiochemical plants is studied. Data were obtained on results of radiochemical analysis of soft tissue and bone samples taken at autopsy from 591 workers of the radiochemical plant. Alpha activity was measured with a low background alpha-radiometer. The patho-morphological state of the liver was taken into account. It is shown that the health state and the grade of the pathological process have an effect upon distribution of systemic Pu in humans. Skeleton to liver ratio is 50.3 : 42.3 = 1.2 for the practically healthy people. As the state of the health worsens and the pathology becomes more scenic, resulting in the fatty degeneration in the hepatocytes, the fractions of Pu deposition in liver decreases, while the fraction in the skeleton increases in the same degree. The individuals with serious liver diseases (cancer, massive metastases in the liver, cirrhosis, alcoholism) have got the ratio the skeleton : the liver = 77.9 : 14.9 = 5.5. The correlation between the state of the state of the health, some domestic factor and the distribution of systemic Pu was studied using the multifactorial regression analysis. These results indicated that Pu redistribution between the liver and the skeleton is the reciprocal process. Under pathological processes the element released from the liver is transported to the skeleton. The intensity of Pu translocation from the liver to the skeleton is higher under pathological processes (28 % for 1 - 2 years) than under the normal life conditions (1.4 % y -1 ). It should be assumed that for the persons with different heavy chronic diseases the skeleton and liver exposure doses may differ from the calculated ones, if the doses are evaluated from the models that do not take into account the plutonium recycling in systemic organs under the pathological processes [ru

Modeling intermediate product selection under production and storage capacity limitations in food processing

DEFF Research Database (Denmark)

Kilic, Onur Alper; Akkerman, Renzo; Grunow, Martin

2009-01-01

In the food industry products are usually characterized by their recipes, which are specified by various quality attributes. For end products, this is given by customer requirements, but for intermediate products, the recipes can be chosen in such a way that raw material procurement costs and pro...... with production and inventory planning, thereby considering the production and storage capacity limitations. The resulting model can be used to solve an important practical problem typical for many food processing industries.......In the food industry products are usually characterized by their recipes, which are specified by various quality attributes. For end products, this is given by customer requirements, but for intermediate products, the recipes can be chosen in such a way that raw material procurement costs...... and processing costs are minimized. However, this product selection process is bound by production and storage capacity limitations, such as the number and size of storage tanks or silos. In this paper, we present a mathematical programming approach that combines decision making on product selection...

Radiochemical neutron activation analysis for trace elements of basic ingredients of pan

International Nuclear Information System (INIS)

Zaidi, J.H.; Arif, M.; Fatima, I; Qureshi, I.H.

2002-01-01

Extensive use of pan, by one-tenth of world's population, entails the evaluation of trace element contents in its ingredients. Radiochemical neutron activation analysis (RNAA) was developed and successfully employed to determine the concentration of 36 trace elements (essential, toxic and nonessential) in its four basic ingredients, leaf of betel pepper, betel nut, catechu and lime. The radiochemical separation methodology has significantly improved the detection limits of most of these elements due to suppression of Compton background. Base-line values of certain toxic and essential elements in these ingredients is provided. The daily intake of essential and toxic elements through pan was estimated and compared with the recommended values. The cumulative intake of Mn is four times higher than the recommended value and that of toxic elements is well below the tolerance limits. (author)

Computer aided design of piping for a radiochemical plant

Energy Technology Data Exchange (ETDEWEB)

Selvaraj, P G; Chandrasekhar, A; Chandrasekar, A V [Reprocessing Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Raju, R P; Mahudeeswaran, K V; Kumar, S V [Reprocessing Group, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

In a radiochemical plant such as reprocessing plants, process equipment, storage tanks, liquid transfer systems and the associated pipe lines etc. are housed in series of concrete cells. Availability of limited cell space/volume, provision of various modes of liquid transfers with associated redundancies and instrumentation lines with standby alternatives increase the overall piping density. Designing such high density piping layout without interference is quite complex and needs lot of human efforts. This paper briefly describes development of computer codes for the entire scheme of design, drafting and fabrication of piping for nuclear fuel reprocessing plant. The general organisation of various programs, their functions, the complete sequence of the scheme and the flow of data are presented. High degree of reliability of each routine, considerable error checking facilities, marking legends on the drawings, provision for scaling in drafting and accuracy to the extent of one mm in layout design are some of the important features of this scheme. (author). 1 fig.

A comparative study using liquid scintillation counting to determine 63Ni in low and intermediate level radioactive waste

International Nuclear Information System (INIS)

Gautier, Celine; Colin, Christele; Garcia, Cecile

2016-01-01

A comparative study using liquid scintillation counting was performed to measure 63 Ni in low and intermediate level radioactive waste. Three dimethylglyoxime (DMG)-based radiochemical procedures (solvent extraction, precipitation, extraction chromatography) were investigated, the solvent extraction method being considered as the reference method. Theoretical speciation calculations enabled to better understand the chemical reactions involved in the three protocols and to optimize them. In comparison to the method based on DMG precipitation, the method based on extraction chromatography allowed to achieve the best results in one single step in term of recovery yield and accuracy for various samples. (author)

Cement-based processes for the immobilization of intermediate level radioactive waste

International Nuclear Information System (INIS)

Brown, D.J.; Lee, D.J.; Price, M.S.T.; Smith, D.L.G.

1985-01-01

Increasing attention is being paid to the use of cement-based materials for the immobilisation of intermediate level wastes. Various cementitious materials are surveyed and the use of blast furnace slag is shown to be advantageous. The properties of cemented wastes are surveyed both during processing and as solid products. The application of Winfrith Cementation Laboratory technology to plant and flowsheet development for Winfrith Reactor sludge immobilisation is described. (author)

Research on the intermediate process of a free-piston linear generator from cold start-up to stable operation: Numerical model and experimental results

International Nuclear Information System (INIS)

Feng, Huihua; Guo, Chendong; Jia, Boru; Zuo, Zhengxing; Guo, Yuyao; Roskilly, Tony

2016-01-01

Highlights: • The intermediate process of free-piston linear generator is investigated for the first time. • “Gradually switching strategy” is the best strategy in the intermediate process. • Switching at the top dead center position timing has the least influences on free-piston linear generator. • After the intermediate process, the operation parameters value is smaller than those before the intermediate process. - Abstract: The free-piston linear generator (FPLG) has more merits than the traditional reciprocating engines (TRE), and has been under extensive investigation. Researchers mainly investigated on the starting process and the stable generating process of FPLG, while there has not been any report on the intermediate process from the engine cold start-up to stable operation process. Therefore, this paper investigated the intermediate process of the FPLG in terms of switching strategy and switching position based on simulation results and test results. Results showed that when the motor force of the linear electric machine (LEM) declined gradually from 100% to 0% with an interval of 50%, and then to a resistance force in the opposite direction of piston velocity (generator mode), the operation parameters of the FPLG showed minimal changes. Meanwhile, the engine operated more smoothly when the LEM switched its working mode from a motor to a generator at the piston dead center, compared with that at the middle stroke or a random switching time. More importantly, after the intermediate process, the operation parameters of FPLG were smaller than that before the intermediate process. As a result, a gradual motor/generator switching strategy was recommended and the LEM was suggested to switch its working mode when the piston arrived its dead center in order to achieve smooth engine operation.

The role of high performance liquid chromatography in radiochemical/radiopharmaceutical synthesis and quality assurance

International Nuclear Information System (INIS)

Boothe, T.E.; Emran, A.M.

1990-01-01

The usefulness of HPLC in all areas of radiopharmaceutics has been demonstrated in numerous laboratories, particularly in the development of in-house radiopharmaceuticals for SPECT and PET. HPLC continues to be a powerful tool in preparation and quality assurance (QA) as illustrated in such areas as chemical and radiochemical identification; product separation and isolation; preparative scale purification; and specific activity determination. A review of established HPLC techniques in radiopharmaceutics will be presented. Examples from the literature as well as newer applications will be used in an attempt to assess and define the present-day role of HPLC in the preparation of radiochemicals and radiopharmaceuticals with emphasis on QA

Diaphragms obtained by radiochemical grafting in PTFE

International Nuclear Information System (INIS)

Nenner, T.; Fahrasmane, A.

1984-01-01

Diaphragms for alkaline water electrolysis are prepared by radiochemical grafting of PTFE fabric with styrene, which is later on sulfonated, or with acrylic acid. The diaphragms obtained are mechanically resistant to potash at temperatures up to 200 0 C, but show some degrafting, which limits the lifetime. The sulfonated styrene group has been found to be more stable in electrolysis than the acrylic acid. In both cases, the incorporation of a cross-linking agent like divinyl benzene improves the lifetime of the diaphragms. Electrolysis during 500 hours at 120 0 C and 10 kAm 2 could be performed. (author)

Rapid radiochemical separation of zirconium-95 and niobium-95

International Nuclear Information System (INIS)

Downey, D.M.; McLaughlin, C.L.

1983-01-01

A rapid method for the quantitative separation of 95 Zr and 95 Nb has been developed. The method is based on the ion flotation of cationic zirconium complex ions with sodium lauryl sulfate (NaLS) from niobium which is masked with hydrogen peroxide. The separation was applied to mixtures of 95 Zr and 95 Nb initially in oxalic acid solution and quantitative recoveries of the radiochemically pure radioisotopes were obtained. (orig.)

Rapid radiochemical methods for preparation of sup(99m)Tc labelled compounds

International Nuclear Information System (INIS)

Narasimhan, D.V.S.; Banodkar, S.M.; Kothari, K.; Mani, R.S.

1981-01-01

Several inorganic and organic compounds incorporating sup( 99 m)Tc are being extensively used for imaging various body organs. The preparation of these sup( 99 m)Tc compounds with the necessary purity requirements is carried out by controlled reduction of sup( 99 m)Tc-pertechnetate using Sn(II) ions as the reducing agent followed by complexation with various active ingredients. The authors here present procedures developed at Radiopharmaceuticals Section of BARC for preparing sup( 99 m)Tc-diphosphonate, sup( 99 m)Tc-glucoheptonate, sup( 99 m)Tc-albumin microspheres and sup( 99 m)Tc-phytate with high radiochemical purity. The paper also describes procedures for the preparation of freeze-dried kits for single step preparation of these compounds. The paper also describes the authors' experience with various analytical procedures for the determination of radiochemical purity of these preparations. (author)

Monitoring deep geodynamic processes within Vrancea intermediate-depth seismic zone by geodetic means

Science.gov (United States)

Besutiu, Lucian; Zlagnean, Luminita

2015-04-01

Background Located in the bending zone of East Carpathians, the so-called Vrancea zone is one of the most active seismic regions in Europe. Despite many years of international research, its intermediate-depth seismicity within full intra-continental environment still represents a challenge of the 21st century. Infrastructure In the attempt to join the above-mentioned efforts, the Solid Earth Dynamics Department (SEDD) in the Institute of Geodynamics of the Romanian Academy has developed a special research infrastructure, mainly devoted to gravity and space geodesy observations. A geodetic network covering the epicentre area of the intermediate-depth earthquakes has been designed and implemented for monitoring deep geodynamic processes and their surface echoes. Within each base-station of the above-mentioned network, a still-reinforced concrete pillar allows for high accuracy repeated gravity and GPS determinations. Results Starting from some results of the previously run CERGOP and UNIGRACE European programmes, to which additional SEDD repeated field campaigns were added, an unusual geodynamic behaviour has been revealed in the area. 1) Crust deformation: unlike the overall uprising of East Carpathians, as a result of denudation followed by erosion, their SE bending zone, with Vrancea epicentre area exhibits a slight subsidence. 2) Gravity change: more than 200 microgals non-tidal gravity decrease over a 20 years time-span has been noticed within the subsiding area. Extended observations showed the gravity lowering as a nowadays continuing process. Interpretation This strange combination of topography subsidence and gravity lowering has been interpreted in terms of crust stretching in the Vrancea epicentre zone due to the gravity pull created by densification of the lower crust as a result of phase-transform processes taking place in the lithospheric compartment sunken into the upper mantle. The occurrence of crust earthquakes with vertical-extension focal

Radiochemical and biological control of metaiodobenzyl-guanidine (MIBG) labeled with 131I

International Nuclear Information System (INIS)

Barboza, M.R.F.F. de; Muramoto, E.; Colturato, M.T.; Silva Valente Goncalves, R. da; Pereira, N.P.S. de; Almeida, M.A.T.M. de; Silva, C.P.G. da.

1988-07-01

This study shows the standardization of the radiochemical control of MIBG - 131 I in eletrophoretic system and also the biological control in Wistar rat for a period of time, not longer than 60 minutes after tracer administration. (author) [pt

Critical evaluation of the determination of zirconium and hafnium by instrumental and radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Burger, Mario; Kraehenbuehl, Urs

1991-01-01

Neutron activation analysis (instrument or radiochemical) is suitable for the determination of zirconium and hafnium in samples of geochemical origin only when sufficient attention is paid to inter-fering nuclides. The size of the necessary correction for INAA depends on the composition of the sample; this problem is discussed. The radio-chemical technique which is recommended involves separation of the samples, precipitations and anion-exchange separation. Results are given for various standard reference materials and for meteorites. (author). 12 refs.; 1 fig.; 9 tabs

The disposal of intermediate-level radioactive liquid waste by hydraulic fracturing process

International Nuclear Information System (INIS)

Chen Ruilin; Zhou Hanchen; Gao Yuzhu; Qiao Wen; Wang Wentao

1993-01-01

The hydraulic fracturing process is characterized by combination of the treatment with the disposal of ILLW (intermediate-level liquid waste). It is of cement solidification in deep geology stratum. First of all, it is necessary to select a suitable disposal site with detailed information on geology and hydrogeology. The process has such advantages as simple, low cost, large capacity of disposal, safe and reliable in technology. It is an attractive process of ILLW. Since 1980's, the research and the concept design of the hydraulic fracturing process have been initiated for disposal of ILLW. It is demonstrated by the field tests. The authors considered that the geological structure near Sichuan Nuclear Fuel Plant fits the disposal of ILLW by the hydraulic fracturing process

The disposal of intermediate-level radioactive liquid waste by hydraulic fracturing process

Energy Technology Data Exchange (ETDEWEB)

Ruilin, Chen; Hanchen, Zhou; Yuzhu, Gao; Wen, Qiao; Wentao, Wang [Beijing Inst. of Nuclear Engineering (China)

1994-12-31

The hydraulic fracturing process is characterized by combination of the treatment with the disposal of ILLW (intermediate-level liquid waste). It is of cement solidification in deep geology stratum. First of all, it is necessary to select a suitable disposal site with detailed information on geology and hydrogeology. The process has such advantages as simple, low cost, large capacity of disposal, safe and reliable in technology. It is an attractive process of ILLW. Since 1980`s, the research and the concept design of the hydraulic fracturing process have been initiated for disposal of ILLW. It is demonstrated by the field tests. The authors considered that the geological structure near Sichuan Nuclear Fuel Plant fits the disposal of ILLW by the hydraulic fracturing process.

Analytical and radiochemical methods in the stability study of the MIBI-Sm

International Nuclear Information System (INIS)

Isaac, M.; Leyva, R.; Gamboa, R.; Turino, D.

1997-01-01

99mT c-MIBI is a radiopharmaceutical imaging agent useful for assessing myocardial perfusion. This paper presents the stability results obtained in the radiochemical purity and others parameters in the quality control of 5 batch during more than 2 years

Radiochemical regularities of migration mobility of Chernobyl' discharge radionuclides

International Nuclear Information System (INIS)

Skorobogat'ko, E.P.; Rybalko, S.I.

1992-01-01

Data on the radionuclude (RN) migration in environment later the Chernobyl' accident are generalized. Introduction of fallout of the radioactive discharge into environment causes necessity to account and to study different factors of geochemical and physicochemical character determining further RN behaviour in the medium. For a well-founded forecast of the behaviour it is necessity to use a complex of radiochemical and physicochemical research, lying in the base of radiation monitoring of environment. 1 refs

Rapid radiochemical separation of zirconium-95 and niobium-95

Energy Technology Data Exchange (ETDEWEB)

Downey, D.M.; McLaughlin, C.L.

1983-01-01

A rapid method for the quantitative separation of /sup 95/Zr and /sup 95/Nb has been developed. The method is based on the ion flotation of cationic zirconium complex ions with sodium lauryl sulfate (NaLS) from niobium which is masked with hydrogen peroxide. The separation was applied to mixtures of /sup 95/Zr and /sup 95/Nb initially in oxalic acid solution and quantitative recoveries of the radiochemically pure radioisotopes were obtained.

Studies of neutron methods for process control and criticality surveillance of fissile material processing facilities

International Nuclear Information System (INIS)

Zoltowski, T.

1988-01-01

The development of radiochemical processes for fissile material processing and spent fuel handling need new control procedures enabling an improvement of plant throughput. This is strictly related to the implementation of continuous criticality control policy and developing reliable methods for monitoring the reactivity of radiochemical plant operations in presence of the process perturbations. Neutron methods seem to be applicable for fissile material control in some technological facilities. The measurement of epithermal neutron source multiplication with heuristic evaluation of measured data enables surveillance of anomalous reactivity enhancement leading to unsafe states. 80 refs., 47 figs., 33 tabs. (author)

Methods for nuclear material control used in the basic production of a typical radiochemical plant

International Nuclear Information System (INIS)

Kositsyn, V.F.; Mukhortov, N.F.; Korovin, Yu.I.; Rudenko, V.S.; Petrov, A.M.

1999-01-01

Techniques for destructive and non-destructive assay of the component and isotopic composition of nuclear materials are described, namely gravimetric, titrimetric, coulometric, mass spectrometry, as well as those based on registration of neutron and γ radiations. Their metrologic characteristics are described. The techniques described are suggested to be used for nuclear material (NM) control and accounting purposes at the model radiochemical plant for processing irradiated fuel subassemblies from power reactors. The measurement control program is also described. This program is intended for the measurement quality assurance in the framework of NM control and accountancy system [ru

13th Radiochemical Conference. Booklet of Abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The Conference included the following sessions: (i) Opening plenary presentations (6 contributions); (ii) Chemistry of natural radionuclides, discovery of radium and polonium (6 verbal presentations + 5 poster presentations); (iii) Radionuclides in the environment, radioecology (29 + 48); (iv) Activation analysis and other radioanalytical methods (36 + 49); (v) Ionizing radiation in science and technology (12 + 12); (vi) Chemistry of actinide and trans-actinide elements (11 + 14); (vii) Separation methods, speciation (18 + 41); (viii) Production and application of radionuclides (14 + 29); and (ix) Radiochemical problems in nuclear waste management (12 + 22). The majority of verbal presentations has been input to INIS, mostly in the form of the full authors` abstracts. (P.A.)

13th Radiochemical Conference. Booklet of Abstracts

International Nuclear Information System (INIS)

1998-04-01

The Conference included the following sessions: (i) Opening plenary presentations (6 contributions); (ii) Chemistry of natural radionuclides, discovery of radium and polonium (6 verbal presentations + 5 poster presentations); (iii) Radionuclides in the environment, radioecology (29 + 48); (iv) Activation analysis and other radioanalytical methods (36 + 49); (v) Ionizing radiation in science and technology (12 + 12); (vi) Chemistry of actinide and trans-actinide elements (11 + 14); (vii) Separation methods, speciation (18 + 41); (viii) Production and application of radionuclides (14 + 29); and (ix) Radiochemical problems in nuclear waste management (12 + 22). The majority of verbal presentations has been input to INIS, mostly in the form of the full authors' abstracts. (P.A.)

Mercury determination in geological samples using radiochemical separation

International Nuclear Information System (INIS)

Goncalves, Cristina; Favaro, Deborah I.T.

1997-01-01

In this work, a radiochemical procedure is presented to increase the neutron activation analysis sensitivity. After irradiation, geological reference materials - Buffalo River Sediment (BRS- - NIST SRM 2704), Lake Sediment (BCR - CRM 280) and GXR-5 (USGS - AEG) - were leached with aqua regia in a Parr bomb placed in a domestic microwave oven and then bismuth diethyl dithiocarbamate was used to pre concentrate mercury by solvent extraction. This procedure eliminates the interference from 279 keV Se-75 photopeak and background radiation from 511 keV Cu-64 photopeak. (author). 15 refs., 2 figs., 1 tab

Studies on some Indian paints for radiochemical plants

International Nuclear Information System (INIS)

Mahesh Kumar, V.V.; Srinivasan, R.; Natarajan, R.

1996-01-01

The choice of paints in areas subjected to contamination and radiation in nuclear installation need special attention. The types of generic coatings are examined with reference to these requirements. Among those examined, certain types of epoxy paints are found to be attractive for these applications. Samples of epoxy paints obtained from some Indian manufacturers are tested for their suitability. Decontaminability and radiation resistance properties are also evaluated with special reference to radiochemical plants. Important specifications for such applications are listed. This report summarizes the results of these studies. (author)

Application of radiochemical methods to investigate mercury in water-ecosystems

International Nuclear Information System (INIS)

Kraemer, H.J.

1975-01-01

Two topics have been picked out of the vast scope of possible questions on mercury ecology in this work: 1) Development for a method of enrichment of mercury from surface water and neutron activation analytical determination of the influence of dissolved Hg compounds on the water/fish part-process taking course in the water-ecosystem with the help of radiochemical tracer methods. The developed enrichment method, adsorbents on aniline sulphur resin basis, was applied to the activation analytical Hg determination in model solutions with a specified content as well as in water of the Rhine, where a Hg content of 1.1 +- 0.2 x 10 -3 ppm was determined. 2) The uptake (and yield) of Hg (NO 3 ) 2 and CH 3 HgCl from fish was traced using radioactive tracers Hg 197 and Hg 203. The measured accumulation and yield kinetics and observed influence due to additions enable the development of model to interpret the interaction between fish and dissolved Hg compounds. (RB) [de

Growth of a manganese nodule from Peru Basin: a radiochemical anatomy

International Nuclear Information System (INIS)

Reyss, J.L.; Lemaitre, N.; Marchig, V.; Southon, J.R.; Nelson, D.E.; Vogel, J.S.

1985-01-01

Attempts have been made to study the entire growth history of a manganese nodule from the northern part of Peru Basin in the Pacific using radiochemical profiles of 230 Th/ 232 Th, 227 Th/ 230 Th and 10 Be/ 9 Be. Combined with the observations on Fe-Mn contents and textural variation, the radiochemical data indicate that the nodule grew more or less concentrically throughout most of its existence since it formed 1.5 my ago, receiving Mn from both bottom water and pore water. This condition appeared to have changed about 180 ky ago when the growth became asymmetric in that the top and bottom sides became fixed in their relative positions on the sea floor. Since then, the bottom side accreted with a fast rate of close to 200 mm/my, apparently fueled by the supply of diagenetically remobilized Mn in pore water from the sediment substrate. In the meantime, the topside accumulated at about 6 mm/my, a value which is in the normal range for deep-sea nodules having their Mn supplied from the hydrogenous source. (author)

A radio-high-performance liquid chromatography dual-flow cell gamma-detection system for on-line radiochemical purity and labeling efficiency determination

DEFF Research Database (Denmark)

Lindegren, S; Jensen, H; Jacobsson, L

2014-01-01

In this study, a method of determining radiochemical yield and radiochemical purity using radio-HPLC detection employing a dual-flow-cell system is evaluated. The dual-flow cell, consisting of a reference cell and an analytical cell, was constructed from two PEEK capillary coils to fit into the w...

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)

Rapid and sensitive enzymatic-radiochemical assay for the determination of triglycerides

International Nuclear Information System (INIS)

Khoo, J.C.; Miller, E.; Goldberg, D.I.

1987-01-01

An enzymatic-radiochemical method suitable for the determination of triglyceride levels of cells in culture is described. The method is based on the enzymatic hydrolysis of triglycerides to free fatty acids which then complex with 63 Ni. The method is rapid, accurate, and inexpensive. The procedure extends the sensitivity of triglyceride measurement to as low as 0.25 nanomoles

Project Title: Radiochemical Analysis by High Sensitivity Dual-Optic Micro X-ray Fluorescence

International Nuclear Information System (INIS)

Havrilla, George J.; Gao, Ning

2002-01-01

A novel dual-optic micro X-ray fluorescence instrument will be developed to do radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford. This concept incorporates new X-ray optical elements such as monolithic polycapillaries and double bent crystals, which focus X-rays. The polycapillary optic can be used to focus X-rays emitted by the X-ray tube thereby increasing the X-ray flux on the sample over 1000 times. Polycapillaries will also be used to collect the X-rays from the excitation site and screen the radiation background from the radioactive species in the specimen. This dual-optic approach significantly reduces the background and increases the analyte signal thereby increasing the sensitivity of the analysis. A doubly bent crystal used as the focusing optic produces focused monochromatic X-ray excitation, which eliminates the bremsstrahlung background from the X-ray source. The coupling of the doubly bent crystal for monochromatic excitation with a polycapillary for signal collection can effectively eliminate the noise background and radiation background from the specimen. The integration of these X-ray optics increases the signal-to-noise and thereby increases the sensitivity of the analysis for low-level analytes. This work will address a key need for radiochemical analysis of high-level waste using a non-destructive, multi-element, and rapid method in a radiation environment. There is significant potential that this instrumentation could be capable of on-line analysis for process waste stream characterization at DOE sites

On the Convergence of Implicit Iterative Processes for Asymptotically Pseudocontractive Mappings in the Intermediate Sense

Directory of Open Access Journals (Sweden)

Xiaolong Qin

2011-01-01

Full Text Available An implicit iterative process is considered. Strong and weak convergence theorems of common fixed points of a finite family of asymptotically pseudocontractive mappings in the intermediate sense are established in a real Hilbert space.

The use of cuprous iodide as a precipitation matrix in the radiochemical determination of 131I in milk

International Nuclear Information System (INIS)

McCurdy, D.E.; Mellor, R.A.; Lambdin, R.W.; McLain, M.E. Jr.

1980-01-01

As a result of the implementation of the As Low As is Reasonably Achievable philosophy to the nuclear power industry, recent U.S. Nuclear Regulatory Commission requirements have prompted high sensitivity radiochemical analysis for the measurement of 131 I in milk. The most recognized and commonly employed technique incorporates costly palladium iodide as the final precipitate in the radiochemical purification of the iodine chemical species. The procedure presented in this paper outlines the many advantages of using cuprous iodide as the final precipitate. These include lower cost per analysis, consistent recoveries, better precipitate matrix and good self absorption characteristics. Typical lower limit of detection values and operating characteristics obtained for high sensitivity β-γ analysis as well as gas proportional counting and a comparison of radiochemical and Ge(Li) spectrometric results for environmental samples collected during a recent Chinese weapons fallout incident are presented. (author)

Limits of the radiochemical and geochemical method for the test of nucleon stability

Energy Technology Data Exchange (ETDEWEB)

Bergamasco, L [CNR, Laboratorio di Cosmo-Geofisica, Turin, Italy; Texas A and M University, College Station, Tex.); Cini, G [CNR, Laboratorio di Cosmo-Geofisica; Torino, Universita, Turin, Italy)

1978-07-01

An estimate is obtained for the limiting nucleon lifetime that can be determined by the radiochemical method of Steinberg and Evans (1977), which counts the Ar-37 production from reactions due to nucleon decay in a large sample of KC2H3O2. To estimate the background rate, processes due to the atmospheric muon component are considered. It is found that the asymptotic limit on the maximum value of the nucleon lifetime is 2 x 10/sup 30/years. This value cannot be increased by going to larger depths or by using a larger sample, but is inherent in the method itself. To improve the limit one would have to resort to methods based on multiparticle decay modes.

III Scientific-technical conference. Problems and outlooks for development of chemical and radiochemical control in atomic energetics (Atomenergoanalytics-2005). Summaries of reports

International Nuclear Information System (INIS)

2005-01-01

Summaries of reports of the III Scientific-technical conference: Problems and outlooks for development of chemical and radiochemical control in atomic energetics (Atomenergoanalytics-2005) are presented. The conference performed 20-22 September, 2005, in Sosnovyj Bor. Problems of methodical, instrumental and metrological supply of chemical, radiochemical and radiometric control at active NPP and NPU, modern concepts of construction of automated systems of chemical and radiometric control in the atomic energetics, directions for the decision of questions in organization and conducting of chemical and radiochemical control of water-chemical regimes of NPP and NPU are discussed [ru

Intermediality: Bridge to Critical Media Literacy.

Science.gov (United States)

Pailliotet, Ann Watts; Semali, Ladislaus; Rodenberg, Rita K.; Giles, Jackie K.; Macaul, Sherry L.

2000-01-01

Defines "intermediality" as the ability to critically read and write with and across varied symbol systems. Relates it to critical media literacy. Offers rationales for teaching critical media literacy in general, and intermedial instruction in particular. Identifies seven guiding intermedial elements: theory, texts, processes, contexts,…

Mixing and sampling tests for Radiochemical Plant

International Nuclear Information System (INIS)

Ehinger, M.N.; Marfin, H.R.; Hunt, B.

1999-01-01

The paper describes results and test procedures used to evaluate uncertainly and basis effects introduced by the sampler systems of a radiochemical plant, and similar parameters associated with mixing. This report will concentrate on experiences at the Barnwell Nuclear Fuels Plant. Mixing and sampling tests can be conducted to establish the statistical parameters for those activities related to overall measurement uncertainties. Density measurements by state-of-the art, commercially availability equipment is the key to conducting those tests. Experience in the U.S. suggests the statistical contribution of mixing and sampling can be controlled to less than 0.01 % and with new equipment and new tests in operating facilities might be controlled to better accuracy [ru

Writing Process Products in Intermediate-Grade Children with and without Language-Based Learning Disabilities

Science.gov (United States)

Koutsoftas, Anthony D.

2016-01-01

Purpose: Difficulties with written expression are an important consideration in the assessment and treatment of school-age children. This study evaluated how intermediate-grade children with and without written language difficulties fared on a writing task housed within the Hayes and Berninger (2014) writing process framework. Method: Sixty-four…

Proceedings of the Tripartite Seminar on Nuclear Material Accounting and Control at Radiochemical Plants; Trudy trekhstoronnego seminara Uchet i kontrol' yadernykh materialov na radiokhimicheskikh ustanovkakh

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The problems of creation and operation of nuclear materials (NM) control and accounting systems and their components at radiochemical plants were discussed in seminar during November 2-6 of 1998. There were 63 Russian and 25 foreign participants in seminar. The seminar programme includes following sessions and articles: the aspects of State NM control and accountancy; NM control and accounting in radiochemical plants and at separate stages of reprocessing of spent nuclear fuel and irradiated fuel elements of commercial reactors; NM control and accountancy in storage facilities of radiochemical plants; NM control and accounting computerization, material balance assessment, preparation of reports; qualitative and quantitative measurements in NM control and accounting at radiochemical plants destructive analysis techniques.

A study on the establishment of the regulatory guide to the characteristics and classification criteria of low and intermediate level radioactive waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Geon Jae; Paek, Min Hoon; Park, Jong Gil; Han, Byeong Seop; Cheong, Jae Hak; Lee, Hae Chan; Yang, Jin Yeong; Hong, Hei Kwan; Park, Jin Baek [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1995-01-15

The objectives of this study are the development of regulatory guidance to the establishment of the necessary technology standard of the characteristics and classification criteria of low and intermediate level radioactive waste for the safe operation of the waste repositories. In followings, the contents of our report will be presented in two parts. Survey of the characteristics of radioactive waste : investigate and analyze the source, types and characteristics of domestic radioactive waste as a basis for this study, radiochemical analysis of radioactive waste based on foreign and domestic data base, determination of the methodology for the application of the characteristic analysis of waste classification technology. Establishment of the classification criteria of the radioactive waste : collection and analysis of foreign and domestic data base on the classification methodology and criteria, development of low and intermediate level waste classification criteria and the set up of the classification methodology through the analysis of waste data, establishment of the systematic classification methodology of the low and intermediate radioactive waste through the careful survey of the current domestic regulation.

Ethanol Production from Different Intermediates of Sugar Beet Processing

Directory of Open Access Journals (Sweden)

Mladen Pavlečić

2010-01-01

Full Text Available In this investigation, the production of ethanol from the raw sugar beet juice and raw sugar beet cossettes has been studied. For ethanol production from the raw sugar beet juice, batch and fed-batch cultivation techniques in the stirred tank bioreactor were used, while batch ethanol production from the raw sugar beet cossettes was carried out in horizontal rotating tubular bioreactor (HRTB. In both cases, Saccharomyces cerevisiae was used as a production microorganism. During batch ethanol production from the raw sugar beet juice, ethanol yield was 59.89 g/L and production efficiency 78.8 %, and in fed-batch process the yield was 92.78 g/L and efficiency 93.4 %. At the same time, ethanol production in HRTB from the raw sugar beet cossettes with inoculum of 16.7 % V/m (raw sugar beet cossettes resulted in the highest ethanol yield of 54.53 g/L and production efficiency of 79.5 %. The obtained results clearly show that both intermediates of sugar beet processing can be successfully used for ethanol production.

A radiochemical analyses of metastudtite and leachates from spent fuel

International Nuclear Information System (INIS)

McNamara, Bruce K.; Hanson, Brady D.; Buck, Edgar C.; Soderquist, Chuck Z.

2004-01-01

Immersion of commercial spent nuclear fuel (CSNF) in deionized water produced two novel corrosion products after a two-year contact period. Another unexpected result was that suspensions of aggregates were observed to form at the air-water interface for each of five samples. These solids were characterized, by SEM and XRD to be nearly pure metastudtite (UO4-2H2O); while the corrosion present on the surface of the fuel itself was determined to be studtite (UO4-2H2O). The occurrence of the floating phase prompted a radiochemical analysis of these solids. This chemical analysis was a unique opportunity to study the relatively pure corrosion phase for incorporation of radionuclides. The analysis indicated that high concentration of 90Sr, 137Cs, 99Tc, and that lower concentrations 237Np, 238, 239Pu and 243, 244Cm had partitioned with the air-water interface aggregates. The concentrations of 241Am were two orders of magnitude lower than the expected inventory in the suspended solids. The radiochemical analyses of the several leachate samples provide preliminary solubility data for the hydrogen peroxide leaching of CSNF and these data are compared to leaching of the same fuel in J-13 and deionized waters. The extent of fuel dissolution in these media are discussed

Triphenyl phosphine oxide as a substoichiometric radiochemical reagent: Determination of thallium

International Nuclear Information System (INIS)

Reddy, P.C.; Polaiah, B.; Rangamannar, B.

1991-01-01

A rapid radiochemical method has been developed for the determination of microgram amounts of thallium based on the substoichiometric extraction of its ocmplex with triphenylphosphine oxide into benzene from 6 M sulphuric acid. 10-90 μg of thallium was determined with an average error of 2.06%. The effect of diverse metal ions on the extraction was studied. (orig.)

Radiochemical separation and alpha-spectrometric determination of Americium in different matrixes

International Nuclear Information System (INIS)

Radenkovic, M.; Joksic, J.; Paligoric, D.

2009-01-01

A method of separation and alpha-spectrometric determination of americium, developed in VINCA Institute of Nuclear Sciences is described in the paper. The procedure is convenient to be used for 241 Am determination in environmental matrixes as well as samples of human origin if a very small concentrations are expected, using 243 Am as a tracer for radiochemical yield recovery. (author) [sr

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

Trace determination of uranium and thorium in biological samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Benedik, Ljudmila; Repinc, Urska; Byrne, Anthony R.; Stegnar, Peter

2002-01-01

Radiochemical neutron activation analysis (RNAA) is an excellent method for determining uranium and thorium; it offers unique possibilities for their ultratrace analysis using selective radiochemical separations. Regarding the favourably sensitive nuclear characteristics of uranium and of thorium with respect to RNAA, but the different half-lives of their induced nuclides, two different approaches were used. In the first approach uranium and thorium were determined separately via 239 U, 239 Np and 233 Pa. In the second approach these elements were 239 239 233 determined simultaneously in a single sample using U and/or Np and Pa. Isolation of induced nuclides was based on separation by extraction and/or anion exchange chromatography. Chemical yields were measured in each sample aliquot using added 235 U, 238 Np and 231 Pa radioisotopic tracers. (author)

RADCHEM - Radiochemical procedures for the determination of Sr, U, Pu, Am and Cm

Energy Technology Data Exchange (ETDEWEB)

Sidhu, R. [Inst. for Energy Technology (Norway)

2006-04-15

An accurate determination of radionuclides from various sources in the environment is essential for assessment of the potential hazards and suitable countermeasures both in case of accidents, authorised release and routine surveillance. Reliable radiochemical separation and detection techniques are needed for accurate determination of alpha and beta emitters. Rapid analytical methods are needed in case of an accident for early decision-making. The objective of this project has been to compare and evaluate radiochemical procedures used at Nordic laboratories for the determination of strontium, uranium, plutonium, americium and curium. To gather detailed information on the procedures in use, a questionnaire regarding various aspects of radionuclide determination was developed and distributed to all (sixteen) relevant laboratories in the Nordic countries. The response and the procedures used by each laboratory were then discussed between those who answered the questionnaire. This report summaries the findings and gives recommendation on suitable practice. (au)

RADCHEM - Radiochemical procedures for the determination of Sr, U, Pu, Am and Cm

International Nuclear Information System (INIS)

Sidhu, R.

2006-04-01

An accurate determination of radionuclides from various sources in the environment is essential for assessment of the potential hazards and suitable countermeasures both in case of accidents, authorised release and routine surveillance. Reliable radiochemical separation and detection techniques are needed for accurate determination of alpha and beta emitters. Rapid analytical methods are needed in case of an accident for early decision-making. The objective of this project has been to compare and evaluate radiochemical procedures used at Nordic laboratories for the determination of strontium, uranium, plutonium, americium and curium. To gather detailed information on the procedures in use, a questionnaire regarding various aspects of radionuclide determination was developed and distributed to all (sixteen) relevant laboratories in the Nordic countries. The response and the procedures used by each laboratory were then discussed between those who answered the questionnaire. This report summaries the findings and gives recommendation on suitable practice. (au)

An overview of the status of radiochemical analysis in Hungary

International Nuclear Information System (INIS)

Solymosi, J.; Toth, G.

1994-01-01

This overview covers the following activities at radioanalytical laboratories in Hungary: tracer techniques and their applications; some important new results; radioimmunoassay; x-ray emission analysis and x-ray fluorescence analysis, Moessbauer-spectroscopy and their applications in various fields of science and technology; neutron activation analysis; radiochemical analysis for nuclear power plant applications activities in various laboratories; nuclear environmental analysis (radioanalytical methods for the investigation of contamination by nuclear facilities). (N.T.) 1 fig.; 7 tabs

Use of reference materials for quality control of elemental analysis by neutron activation with radiochemical separation

International Nuclear Information System (INIS)

Woittiez, J.R.W.

1990-01-01

This paper describes the use of certified reference materials to monitor the long-term quality of radiochemical separations. The practical limitations which determine the actual design of the quality control are discussed. The hypothesis that the high yield of the radiochemical separation will be constant with time has been checked and validated for the elements Zn, Fe, Co, Cd, Mo and to a lesser extent for W and Th using NBS SRM 1577A, BCR CRM 274 and IAEA RM A-11. This validation could not be made for the elements Cr, Au, and Ag. Especially for Cr there is a serious lack of appropiate certified reference materials. (orig.)

Radiochemical aging of an epoxy network; Vieillissement radiochimique d'un reseau epoxyde

Energy Technology Data Exchange (ETDEWEB)

Devanne, Th

2003-05-01

This thesis is to give a better understanding of the radiochemical aging of a thermoset resin under gamma irradiation. The conditions of aging are gamma irradiation under air with a dose rate of 2 kGy/h at 120 C. The requested lifetime is four years, it means a dose of 70 MGy. The first step of this work was the choice of a resistive epoxy resin. This choice was made thanks to the literature data. The high glass transition temperature and the high amount of aromatic groups were the main criteria of the final choice. After this choice, thermal and mechanical properties were followed under thermal and radiochemical aging: i) under thermal aging, after 600 hours at 220 C, the glass transition temperature remained unchanged. But, from a mechanical point of view, properties at break dramatically decreased. This embrittlement was assigned to a critical oxidized layer. The thickness of this layer was estimated about 30 {mu}m. ii) the same kind of embrittlement was observed under radiochemical aging. Moreover, it appeared a decrease of the glass transition temperature when increasing the dose of irradiation. This indicates that the main degradation mechanism is chain scission under anaerobic atmosphere. We, then, proposed a mechanistic model associated with a kinetic model to predict the evolution of the glass transition temperature depending on the irradiation conditions. Parameters of the kinetic model were determined by solid NMR and ESR experiments. Comparison between experimental and calculated values at 120 C is satisfactory, a global good agreement was found. (author)

On the radiochemical purity of elementary 35S with high specific activity

International Nuclear Information System (INIS)

Todorovsky, D.S.; Kostadinov, K.N.; Efremova, Yu.N.

1979-01-01

Radiochemical composition and chemical changes with increasing storage time of benzene solutions and of solid species of elementary 35 S with high specific activity are studied. The dependence of the stability on the specific activity and the radioactive concentration is shown and some tentative limits are given for permissible storage periods. (author)

Self-decomposition of radiochemicals. Principles, control, observations and effects

International Nuclear Information System (INIS)

Evans, E.A.

1976-01-01

The aim of the booklet is to remind the established user of radiochemicals of the problems of self-decomposition and to inform those investigators who are new to the applications of radiotracers. The section headings are: introduction; radionuclides; mechanisms of decomposition; effects of temperature; control of decomposition; observations of self-decomposition (sections for compounds labelled with (a) carbon-14, (b) tritium, (c) phosphorus-32, (d) sulphur-35, (e) gamma- or X-ray emitting radionuclides, decomposition of labelled macromolecules); effects of impurities in radiotracer investigations; stability of labelled compounds during radiotracer studies. (U.K.)

A radiochemical technique for the determination of mercury in drinking water

International Nuclear Information System (INIS)

Ahmad, S.; Chaudhri, M.S.; Qureshi, I.H.

1982-01-01

A radiochemical method for the separation and determination of mercury in drinking water has been developed. The radionuclides of mercury formed after neutron irradiation of the sample were separated by liquid/liquid extraction using PAN and TBA mixture in chloroform from aqueous nitric acid medium. Quantitative extraction of mercury was achieved in a single step and the equilibrium was attained within five minutes. (orig.)

Characterization of filter cartridges from the IEA-R1 reactor by radiochemical method

International Nuclear Information System (INIS)

Geraldo, Bianca; Vicente, Roberto; Ferreira, Robson J.; Goes, Marcos M.; Marumo, Julio T.

2015-01-01

The filter cartridges used in water purification system of research nuclear reactor IEA-R1 are considered radioactive wastes after their useful life. The characterization of these wastes is one of the stages of management, which aims to identify and quantify the radionuclides present, including those known as 'difficult to measure' (DTM) radionuclides. Establish a radiochemical analysis methodology for this type of waste is a difficult job, not only by the application of these techniques, but also by the amount of radionuclides that should be analyzed. In the waste produced in a nuclear reactor, the most important radionuclides are fission products, activation products and transuranic elements. Since these radionuclides emit gamma radiation not measurable in its decay process and consequently are difficult to measure, their concentrations can be estimated by indirect methods such as scale factors. This method is used to evaluate the DTM concentration, which is represented by alpha and beta nuclides using the correlation between them and the radionuclide key, a gamma emitter. The objective of this work is to describe a radiochemical analysis methodology for gamma emitter nuclides, present in the filter cartridges, evaluating the activity and concentrations by destructive assays. At the same time, two studies have been performed by non-destructive assays, the first one based on dose rates and the point kernel method to correlate the results and the second one based on calibration efficiency with Monte Carlo method. These studies belong to the radioactive waste characterization program that has been conducted at the Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. (author)

Characterization of filter cartridges from the IEA-R1 reactor by radiochemical method

Energy Technology Data Exchange (ETDEWEB)

Geraldo, Bianca; Vicente, Roberto; Ferreira, Robson J.; Goes, Marcos M.; Marumo, Julio T., E-mail: bgeraldo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The filter cartridges used in water purification system of research nuclear reactor IEA-R1 are considered radioactive wastes after their useful life. The characterization of these wastes is one of the stages of management, which aims to identify and quantify the radionuclides present, including those known as 'difficult to measure' (DTM) radionuclides. Establish a radiochemical analysis methodology for this type of waste is a difficult job, not only by the application of these techniques, but also by the amount of radionuclides that should be analyzed. In the waste produced in a nuclear reactor, the most important radionuclides are fission products, activation products and transuranic elements. Since these radionuclides emit gamma radiation not measurable in its decay process and consequently are difficult to measure, their concentrations can be estimated by indirect methods such as scale factors. This method is used to evaluate the DTM concentration, which is represented by alpha and beta nuclides using the correlation between them and the radionuclide key, a gamma emitter. The objective of this work is to describe a radiochemical analysis methodology for gamma emitter nuclides, present in the filter cartridges, evaluating the activity and concentrations by destructive assays. At the same time, two studies have been performed by non-destructive assays, the first one based on dose rates and the point kernel method to correlate the results and the second one based on calibration efficiency with Monte Carlo method. These studies belong to the radioactive waste characterization program that has been conducted at the Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. (author)

Development of radiochemical separation method for determination of toxic elements in biological samples

International Nuclear Information System (INIS)

Maihara, V.A.; Vasconcellos, M.B.A.; Favaro, D.I.T.; Armelin, M.J.A.

1990-01-01

In order to determine Hg, Sb, As and Se in biological materials by neutron activation analysis, a radiochemical separation was developed. The chemical separation procedure used was based on the digestion of the irradiated sample in a mixture of H NO 3 and H 2 SO 4 in a teflon bomb, at 130 0 C for 1 to 4 hours. After the dissolution of organic matter, Hg and Sb were retained by a Dowex 2-X8 resin column in 6 M HCl. The effluent was passed through a TDO, tin dioxide column which retains As and Se in 3 M HCl medium. Radioactive tracers of these elements were used to determine the yields of the separation process. Certified reference materials were analyzed to check the precision and accuracy of the method. (author)

Development of a radiochemical separation method for toxic elements determination from biologic samples

International Nuclear Information System (INIS)

Malhara, V.A.; Vasconcellos, M.B.A.; Favaro, D.I.T.; Armelin, M.J.A.

1990-01-01

In order to determine Hg, Sb, As and Se in biological materials by neutron activation analysis, a radiochemical separation was developed. The chemical separation procedure used was based on the digestion of the irradiated sample in a mixture of HNO 3 and H 2 SO 4 in a teflon bomb, at 130 0 C for 1 to 4 hours. After the dissolution of organic matter, Hg and Sb were retained by a Dowex 2-XB resin column in 6M HCI. The efluent was passed through a TDO, tin dioxide column which retains As and Se in 3M HCI medium. Radioactive tracers of these elements were used to determine the yields of the separation process. Certified reference materials were analyzed to check the precision and accuracy of the method. (author)

Radiochemical analysis of chlorine-36

International Nuclear Information System (INIS)

Rodriguez, M.; Pina, G.; Lara, E.

2006-01-01

The radioactive chlorine isotope, 36 Cl, decays with a half-life of 3x10 5 years by emitting a beta particle (98 %) and by electron capture. The aim of this paper is to propose a radiochemical separation method of 36 Cl from the other beta-gamma emitters present in low and medium radioactive wastes such as spent ion exchange resins and evaporator concentrates, that arise from Nuclear Power Plants and particularly in the wastes that come from decommissioning activities of graphite reactors, in order to provide data for 36 Cl inventory calculations. The separation method proposed is based on an oxidation technique where chlorine is trapped by NaOH. 36 Cl beta emissions are measured by liquid scintillation counting by the dual label technique in order to avoid the contamination produced by 14 C which is also trapped by NaOH and which is the main contaminant present in graphite samples. The sensitivity of this method is sufficient to achieve the needed thresholds for the radiological characterization of the radioactive materials to which this method can be applied. (author)

Collected radiochemical and geochemical procedures

Energy Technology Data Exchange (ETDEWEB)

Kleinberg, J [comp.

1990-05-01

This revision of LA-1721, 4th Ed., Collected Radiochemical Procedures, reflects the activities of two groups in the Isotope and Nuclear Chemistry Division of the Los Alamos National Laboratory: INC-11, Nuclear and radiochemistry; and INC-7, Isotope Geochemistry. The procedures fall into five categories: I. Separation of Radionuclides from Uranium, Fission-Product Solutions, and Nuclear Debris; II. Separation of Products from Irradiated Targets; III. Preparation of Samples for Mass Spectrometric Analysis; IV. Dissolution Procedures; and V. Geochemical Procedures. With one exception, the first category of procedures is ordered by the positions of the elements in the Periodic Table, with separate parts on the Representative Elements (the A groups); the d-Transition Elements (the B groups and the Transition Triads); and the Lanthanides (Rare Earths) and Actinides (the 4f- and 5f-Transition Elements). The members of Group IIIB-- scandium, yttrium, and lanthanum--are included with the lanthanides, elements they resemble closely in chemistry and with which they occur in nature. The procedures dealing with the isolation of products from irradiated targets are arranged by target element.

Leakage evaluation in the PCV (Primary Containment Vessel) using chemical and radiochemical data

International Nuclear Information System (INIS)

Maeda, Katsuji; Nagasawa, Katsumi

1998-01-01

Keeping the reliability of nuclear power plant operation, the primary coolant leakage in the PCV is strictly restricted by the Technical Specifications. It is very important to detect an indication of leakage and estimate the source of leakage to provide countermeasures. Usually the indication of leakage will be detected by increase of drain flow in the PCV sump. There are some possibilities of leakage sources in the PCV, such as reactor water, main steam, condensate, feedwater and closed cooling water. The leakage source contain different chemical and radiochemical species. This means that the leakage source can be presumed and detected by using chemical information from the PCV atmosphere and sump water. To detect the leakage indication and the source quickly and exactly, the PCV Leakage Detection Expert System has been developed. This paper describes how to evaluate the leakage indication and source in the PCV by using chemical and radiochemical data. (author)

Advice concerning the advantages of a reference incinerator for low-level and intermediate-level radioactive waste processing

International Nuclear Information System (INIS)

Luyten, G.B.

1985-05-01

In this report, an inventory is presented of new incinerators and flue gas filters used in low and intermediate-level radioactive waste combustion. It is argued that a 'reference equipment' for the combustion of solid and liquid low- and intermediate-level wastes best meets existing Dutch radiation protection standards. A cost-benefit analysis of such an equipment is given including annual costs of investment, capital and exploration. A separate combustion process of organic liquids and carrions is considered finally. (G.J.P.)

Planning for maintenance in radiochemical facilities [Paper No.: VB-2

International Nuclear Information System (INIS)

Balasubramanian, G.R.

1981-01-01

Reprocessing facilities in the earlier stages of development were planned mainly based on the concept of direct maintenance in view of the inherent advantage of man-machine interface and initial savings in the investment costs. With the mechanical processes finding a firm place in head-end operation and increase in down time necessary for elaborate decontamination efforts even for a minor modification has led to the review of the concept. For the same reason, the recent plants are based on the concept of harmonious blend of both direct and remote maintenance. The paper describes the planning needed from consideration of various aspects related to such concepts of maintenance during different phases of such type of facilities, highlighting some of the tools and special equipments to be developed for this purpose. A brief description of recent development in the field of remote maintenance is also given. Though the basic hot facility of reference is the one of reprocessing fast reactor fuels, the concepts and systems discussed are equally applicable to other radiochemical and radiometallurgical facilities also. (author)

On-Line Monitoring for Control and Safeguarding of Radiochemical Streams at Spent Fuel Reprocessing Plant

International Nuclear Information System (INIS)

Bryan, Samuel A.; Levitskaia, Tatiana G.; Billing, Justin M.; Casella, Amanda J.; Johnsen, Amanda M.; Peterson, James M.

2009-01-01

Advanced techniques enabling enhanced safeguarding of the spent fuel reprocessing plants are urgently needed. Our approach is based on prerequisite that real time monitoring of the solvent extraction flowsheets provides unique capability to quickly detect unwanted manipulations with fissile isotopes present in the radiochemical streams during reprocessing activities. The methods used to monitor these processes must be robust and must be able to withstand harsh radiation and chemical environments. A new on-line monitoring system satisfying these requirements and featuring Raman spectroscopy combined with a Coriolis and conductivity probes, has been recently developed by our research team. It provides immediate chemical data and flow parameters of high-level radioactive waste streams with high brine content generated during retrieval activities from Hanford nuclear waste storage tanks. The nature of the radiochemical streams at the spent fuel reprocessing plant calls for additional spectroscopic information, which can be gained by the utilization of UV-vis-NIR capabilities. Raman and UV-vis-NIR spectroscopies are analytical techniques that have extensively been extensively applied for measuring the various organic and inorganic compounds including actinides. The corresponding spectrometers used under the laboratory conditions are easily convertible to the process-friendly configurations allowing remote measurements under the flow conditions. A fiber optic Raman probe allows monitoring of the high concentration species encountered in both aqueous and organic phases within the UREX suite of flowsheets, including metal oxide ions, such as uranyl, components of the organic solvent, inorganic oxo-anions, and water. The actinides and lanthanides are monitored remotely by UV-vis-NIR spectroscopy in aqueous and organic phases. In this report, we will present our recent results on spectroscopic measurements of simulant flowsheet solutions and commercial fuels available at

New radiochemical methods for determination of 237Np a 241Pu using extraction chromatography (Presentation)

International Nuclear Information System (INIS)

Strisovska, J.

2013-01-01

Thesis was focused on the development of a new methodology for the separation of anthropogenic transuranium radionuclides 237 Np a 241 Pu from different kinds of matrices. The analytical methods used in this study were based on extraction chromatography and were optimized according to the sample type. The proposed radiochemical procedure is a combination of two algorithms, which represent the separation of radionuclides by using extraction chromatographic sorbents TEVA resin and TRU resin supplied by Eichrom Technologies LLC. 239 Np a 237 Np were selectively captured on sorbent TEVA resin in oxidation state 4+. TRU resin was used for purification of plutonium fraction from interfering americium radionuclide. 242 Pu and 239 Np radionuclides as tracers have been used to monitor the radiochemical yields of separation. Before every radiochemical separation tracer radionuclide 239 Np was obtained by separation from the parent radionuclide 2 43 Am, which is in radioactive equilibrium to 239 Np. The average yield of chemical separation was 69,3% for 239 Np at 277 keV energy line and 65,9% at 228 keV energy line. The NPL AH-B08069 (2008) samples which consist of the mixture of alpha-radionuclides were used for the modification and optimization of separation method used for separation of Np and Pu in model samples. This method provided high radiochemical yields of 239,240 Pu (95,0 ± 3,5)% and 237 Np (87,9 ± 3,0)%.. Reliability of the method was verified by applying our modified separation procedures on reference materials IAEA-375 and IAEA-414 supplied by International Atomic Energy Agency. A good agreement between the results is obtained by this procedure and the certified values were found. Samples of contaminated soils from the area of Nuclear power plant A-1 Jaslovske Bohunice which is stored temporarily before disposal were analyzed using developed separation procedure. Specific activity of investigated radionuclides was determined in these samples. (author)

Requirement of radiochemical recovery determination for gross alpha and gross beta estimation in drinking water

International Nuclear Information System (INIS)

Raveendran, Nanda; Rao, D.D.; Hegde, A.G.

2010-01-01

Presence of radionuclides in drinking water which emits Alpha and Beta particles are the potential sources of internal exposure in drinking water. Gross alpha and gross beta determination in drinking water and packaged drinking water (PDW) as per BIS (Bureau of Indian standards) standards is discussed here. The methods have been tested to account for losses in the radiochemical procedures using radionuclides such as 137 Cs, 90 Sr, 226 Ra, 239 Pu, 243 Am, 232 U. The methods have also been validated in an IAEA proficiency test conducted during 2009. Monitoring of gross alpha and gross beta activity observed in drinking water/packaged drinking water from various states of India were within the limits set by BIS. Average radiochemical recoveries of 84% and 63% were obtained for gross α and gross β respectively. (author)

Determination of gold and platinum in biological materials by radiochemical neutron activation analysis using electrolytic separation of gold

International Nuclear Information System (INIS)

Reitz, B.; Heydorn, K.

1993-01-01

A new method is presented for the determination of Au and Pt in biological materials based on neutron activation analysis with radiochemical separation of gold. Separation of gold by electrolytic deposition on a niobium cathode ascertains thee highest radiochemical purity without any interference from calcium or other major elements. With 199 Au as indicator for platinum the gold content of the sample not only strongly affects the limit of detection, but also causes interference by double neutron capture. Replicate analyses of BCR Certified Reference Materials No. 184, 185 and 186 were carried out. (author) 18 refs.; 3 figs.; 2 tabs

Determination of rhenium in biological and environmental samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Kucera, J.; Mizera, J.; Randa, Z.; Byrne, A.R.; Lucanikova, M.

2006-01-01

Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1 M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1 M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng.g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng.g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of approx. 10 ng.g -1 was found. Significantly elevated values of Re, up to 90 ng.g -1 , were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggest possible competition between Re and Tc in the accumulation process. (author)

The use of radiochemical analysis for detecting biotracers of food radioactive contamination in Cherkasy Region

International Nuclear Information System (INIS)

Matvyijenko, D.G.

2003-01-01

Stable biotracers of radioactive contamination according to the findings of analytical control of the foodstuffs was determined. The use of radiochemical analysis for determining the activity of the foodstuffs and water (Sr-90, Cs-137) was evaluated

A direct reading on-line flowrate meter for use in radiochemical plant

International Nuclear Information System (INIS)

Shah, B.V.; Kaimal, C.K.R.; Siddiqui, I.A.; Kumar, S.V.

1987-01-01

A device for measurement and remote direct reading display of the flowrates of streams in a radiochemical plant is described. The device is interposed in the measured stream and consists of a syphon pot with a specially developed attachment on the discharge line. Differential pressure switches are used to trigger a timer device at set levels in the pot and the time required for filling the pot during each cycle is measured and is used to compute and display the flowrate. The device is accurate and reliable and is simple to fabricate and install. It is maintenance-free since it has no moving parts. It is also suggested that a manometer with conductive contacts could be used in place of the d.p. switches. The background and various stages of development of the device are described. The operating data is tabulated and parameters required for plant applications are indicated in detail. A simple method to detect and correct for errors due to drift in d.p. switch setting is also outlined. Sketches of typical syphon pot, the schematic of the apparatus and suggested layout for application in radiochemical plant are also included. (author). 11 figures, 6 tables

Intermediate algebra & analytic geometry

CERN Document Server

Gondin, William R

1967-01-01

Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

Radiochemical assay for determination of dihydropyrimidinase activity using reversed-phase high-performance liquid chromatography

NARCIS (Netherlands)

van Kuilenburg, A. B.; van Lenthe, H.; van Gennip, A. H.

1999-01-01

A radiochemical assay was developed to measure the activity of dihydropyrimidinase (DHP) in human liver homogenates. The method is based on the separation of radiolabeled dihydrouracil from N-carbamyl-beta-alanine by HPLC with on-line detection of radioactivity combined with detection of 14CO2 by

Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1989 through 1991

International Nuclear Information System (INIS)

Bartholomay, R.C.; Orr, B.R.; Liszewski, M.J.; Jensen, R.G.

1995-08-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains a continuous monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1989-91. Water in the eastern Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from irrigation water, infiltration of streamflow, and ground-water inflow from adjoining mountain drainage basins. Water levels in wells throughout the INEL generally declined during 1989-91 due to drought. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEL decreased or remained constant during 1989-91. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption processes, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEL were variable during 1989-91. Sodium and chloride concentrations in the southern part of the INEL increased slightly during 1989-91 because of increased waste-disposal rates and a lack of recharge from the Big Lost River. Plumes of 1,1,1-trichloroethane have developed near the Idaho Chemical Processing Plant and the Radioactive Waste Management Complex as a result of waste disposal practices

Cleanout and decontamination of radiochemical hot cells

International Nuclear Information System (INIS)

Surma, J.E.; Holton, L.K. Jr.; Katayama, Y.B.; Gose, J.E.; Haun, F.E.; Dierks, R.D.

1990-01-01

The Pacific Northwest Laboratory is developing and employing advanced remote and contact technologies in cleaning out and decontaminating six radiochemical hot cells at Hanford under the Department of Energy's Surplus Facilities Management Program. The program is using a series of remote and contact decontamination techniques to reduce costs and to significantly lower radiation doses to workers. Refurbishment of the cover blocks above the air lock trench reduced radiation exposure in the air lock and cleanout and decontamination of an analytical cell achieved a reduction in radioactive contamination. Nuclear Regulatory Commission-approved Type B burial boxes are also being used to reduce waste disposal costs and radiation doses. PNL is currently decommissioning its pilot-scale radioactive liquid-fed ceramic melter. Special tools have been developed and are being used to accomplish the world's first such effort. 4 refs., 5 figs

Radiochemical Analysis Methodology for uranium Depletion Measurements

Energy Technology Data Exchange (ETDEWEB)

Scatena-Wachel DE

2007-01-09

This report provides sufficient material for a test sponsor with little or no radiochemistry background to understand and follow physics irradiation test program execution. Most irradiation test programs employ similar techniques and the general details provided here can be applied to the analysis of other irradiated sample types. Aspects of program management directly affecting analysis quality are also provided. This report is not an in-depth treatise on the vast field of radiochemical analysis techniques and related topics such as quality control. Instrumental technology is a very fast growing field and dramatic improvements are made each year, thus the instrumentation described in this report is no longer cutting edge technology. Much of the background material is still applicable and useful for the analysis of older experiments and also for subcontractors who still retain the older instrumentation.

Regularities of intermediate adsorption complex relaxation

International Nuclear Information System (INIS)

Manukova, L.A.

1982-01-01

The experimental data, characterizing the regularities of intermediate adsorption complex relaxation in the polycrystalline Mo-N 2 system at 77 K are given. The method of molecular beam has been used in the investigation. The analytical expressions of change regularity in the relaxation process of full and specific rates - of transition from intermediate state into ''non-reversible'', of desorption into the gas phase and accumUlation of the particles in the intermediate state are obtained

Primary processes initiated by nuclear transformations in solids

International Nuclear Information System (INIS)

Sano, Hirotoshi

1975-01-01

Primary processes of hot atom production initiated by nuclear transformation were discussed from past studies using Moessbauer spectroscopy. Many insulators (dielectric substances) showed various effect, such as abnormaly oxdized condition, following nuclear disintegration within the time duration of the life of Moessbauer nuclear excited state. Supposing these hot atom processes belonged to radiochemical processes, radiochemical characteristics of a certain chemical substance could be clarified by placing Moessbauer nuclide in the neighbourhood of the chemical substance to be studied. Chemical effects of disintegrated atom in the first and second composition, chemical substances produced in the surroundings of disintegrated atom, and environmental disturbance of disintegrated atom were studied and discussed. (Tsukamoto, Y.)

International intercalibration as a method for control of radiochemical analyses

International Nuclear Information System (INIS)

Angelova, A.; Totseva, R.; Karaivanova, R.; Dandulova, Z.; Botsova, L.

1994-01-01

The participation of the Radioecology Section at the National Centre for Radiology and Radiation Protection (NCRRP) in the International Interlaboratory Comparison of radiochemical analyses organized by WHO is reported. The method of evaluating accuracy of the results from inter calibrations concerning radionuclide determination of environmental samples is outlined. The data from analysis of cesium 137, strontium 90 and radium 226 in milk, sediments, soil and seaweed made by 21 laboratories are presented. They show a good accuracy values of the results from NCRRP. 1 tab. 2 figs., 6 refs

Preparation of proton rich radionuclides in support of radiochemical analysis

International Nuclear Information System (INIS)

Jerome, Simon; Larijani, Cyrus; Parker, David

2012-01-01

The production of proton rich radionuclides supports a wide range of radiochemical analyses via radioactive yield tracers ( 95m Tc and 236 Pu). In recent years, NPL and the University of Birmingham cyclotron have collaborated to produce these, and other, radionuclides. - Highlights: ► In this paper we options for the production of Tc and Pu tracers. ► The irradiation and measurement of targets producing Tc-95 m and Pu-236 are described. ► Options for production are discussed. ► The results of this study and future work needed are described.

Determination of mercury in biologycal samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Suc, N.V.

1989-01-01

The radiochemical neutron activation analysis was applied to determine contents of mercury in biological samples. Samples were digested in mixing of H 2 SO 4 and HNO 3 acid. After extraction of mercury by Ni-Ditiodietylphosphoric acid in carbontetrachloride, mercury was back extracted by 5% KI solution. Contents of mercury from five samples of fish was determined by this method. The accuracy of the method was checked by comparing it with NBS standard samples and results are good agreement

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

Radiochemical analyses of several spent fuel Approved Testing Materials

International Nuclear Information System (INIS)

Guenther, R.J.; Blahnik, D.E.; Wildung, N.J.

1994-09-01

Radiochemical characterization data are described for UO 2 and UO 2 plus 3 wt% Gd 2 O 3 commercial spent nuclear fuel taken from a series of Approved Testing Materials (ATMs). These full-length nuclear fuel rods include MLA091 of ATM-103, MKP070 of ATM-104, NBD095 and NBD131 of ATM-106, and ADN0206 of ATM-108. ATMs 103, 104, and 106 were all irradiated in the Calvert Cliffs Nuclear Power Plant (Reactor No.1), a pressurized-water reactor that used fuel fabricated by Combustion Engineering. ATM-108 was part of the same fuel bundle designed as ATM-105 and came from boiling-water reactor fuel fabricated by General Electric and irradiated in the Cooper Nuclear Power Plant. Rod average burnups and expected fission gas releases ranged from 2,400 to 3,700 GJ/kgM. (25 to 40 Mwd/kgM) and from less than 1% to greater than 10%, respectively, depending on the specific ATM. The radiochemical analyses included uranium and plutonium isotopes in the fuel, selected fission products in the fuel, fuel burnup, cesium and iodine on the inner surfaces of the cladding, 14 C in the fuel and cladding, and analyses of the gases released to the rod plenum. Supporting examinations such as fuel rod design and material descriptions, power histories, and gamma scans used for sectioning diagrams are also included. These ATMs were examined as part of the Materials Characterization Center Program conducted at Pacific Northwest Laboratory provide a source of well-characterized spent fuel for testing in support of the US Department of Energy Office of Civilian Radioactive Waste Management Program

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.

The Role of Intermediates in the Process of Red Ferric Pigment Manufacture from FeSO4.7H2O

International Nuclear Information System (INIS)

Zboril, Radek; Mashlan, Miroslav; Petridis, Dimitris; Krausova, Dagmar; Pikal, Petr

2002-01-01

One method of industrial manufacture of red ferric pigments is based on the thermal decomposition of FeSO 4 .7H 2 O into α-Fe 2 O 3 (copperas red). The difficult reproducibility of the color quality of the final pigment is the main problem of this process. One of the factors that can influence the pigment color is contamination by some of the intermediates formed during the transformation process. The identification of two groups of intermediates is the basic result of an extensive laboratory investigation carried out using 57 Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The first group of intermediates includes sulfato-phases as FeSO 4 .H 2 O, FeSO 4 , Fe(OH)SO 4 , Fe 2 O(SO 4 ) 2 , Fe 2 O(SO 4 ) 2 .xH 2 O x element of (0,1), and Fe 2 (SO 4 ) 3 . Thermally metastable polymorphs of iron(III) oxide, β-Fe 2 O 3 , γ-Fe 2 O 3 and ε-Fe 2 O 3 , represent the other group. Moessbauer characterization of all intermediate products is given. A significant influence of β-Fe 2 O 3 on the pigment color was found.

Protein binding studies with radiolabeled compounds containing radiochemical impurities. Equilibrium dialysis versus dialysis rate determination

DEFF Research Database (Denmark)

Honoré, B

1987-01-01

The influence of radiochemical impurities in dialysis experiments with high-affinity ligands is investigated. Albumin binding of labeled decanoate (97% pure) is studied by two dialysis techniques. It is shown that equilibrium dialysis is very sensitive to the presence of impurities resulting...

A radiochemical assay for detection of leukotriene B4 production from isolated cells

International Nuclear Information System (INIS)

Aharony, D.; Dobson, P.; Krell, R.D.

1984-01-01

A radiochemical procedure for quantitating the effect of inhibitors of leukotriene B4 (LTB4) biosynthesis is described. Rat peritoneal cells were labeled with 3 H-arachidonic acid and stimulated with the calcium ionophore A23187. 3 H-LTB4 was isolated by processing on C18-Sep Pak cartridges followed by reverse-phase high pressure liquid chromatography (HPLC). The identity of this product, as well as other arachidonic acid metabolites, was verified by using silicic acid column chromatography followed by straight-phase HPLC and thin layer chromatography. Using this assay, LTB4 release by ionophore A23187 has been shown to be both time- and concentration-dependent. Indomethacin enhanced, while NDGA and ETYA inhibited, the A23187-induced production of LTB4. This procedure is both simple and direct and is capable of assessing the ability of novel compounds to alter LTB4 production

Evaluation of different detection systems to determine the radiochemical purity of the technetium eluate and the radiopharmaceutical sestamibi

Energy Technology Data Exchange (ETDEWEB)

Santos, Poliane Angelo de L.; Andrade, Wellington G., E-mail: polianeangelo@gmail.com, E-mail: wandrade@cnen.gov.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Santos, Luiz Antonio P.; Lima, Fabiana Farias de, E-mail: luanps@uol.com.br, E-mail: fflima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN/CNEN-PE), Recife, PE (Brazil)

2013-07-01

Since 2008 the Brazilian Health Surveillance Agency (ANVISA) has imposed some rules requiring that Nuclear Medicine Services (NMS) perform a minimum of tests with the radiopharmaceuticals before they are administered to their patients according to the Resolution n. 38 (RDC 38). Among the tests, the radiochemical purity is very important because the effectiveness for the use in vivo, and the fact radiochemical impurities may increase the radiation dose beyond to cause some damage in the diagnostic images. Radiochemical Purity is determined by ascendant chromatography technique and when it is used by NMS, the strips are analyzed in dose calibrator. Furthermore, the low activity on the strips can produce errors due to the low detection of this equipment type. Therefore, the aim of this paper is to compare different methods for determining the radiochemical purity of {sup 99m}Tc eluate and {sup 99m}Tc-MIBI radiopharmaceutical; gamma camera, and dose calibrator. The study was developed in three clinics in Recife-PE, and 15 analyses were performed to determine radiochemical purity of technetium eluate and {sup 99m}Tc-MIBI. For evaluating technetium eluate it was used Whatman® 3MM paper in 1cmx8cm strips. On the other hand, for analyzing MIBI radiopharmaceutical it was used 3 Whatman® 3MM paper strips and 3 with silica gel in 1cmx6.5cm format. According to the manufactures, an 1cm point from the base of the strip was labeled. It was dropped 50μ1 of sodium pertechnetate and {sup 99m}Tc-MIBI and, then, the strips were put in the glass tank, with solvent, according to the pharmacopoeia and inserts of the drug manufacturers. After the solvent front reached the end point, the strips were removed and allowed to dry. Firstly, the radioactivity count was made with a gamma camera. After that, the strips were cut in half (eluate) and in 2.5 cm from the base (MIBI) and measured with a dose calibrator. The results of the average radiochemical purity of the eluate in clinics A, B

Chemical and radiochemical control of the primary circuit of Atucha INPP (Nuclear Power Plant) since the start up in January 1990

International Nuclear Information System (INIS)

Ali, S.P; Baungartner, E.C.; Blesa, M.A.

1990-01-01

Since the start up of Atucha I Nuclear Power Plant in January 1990, an exhaustive chemical and radiochemical control of primary media was undertaken. The main objectives were the evaluation of the water condition after the long outage and the determination of activity measurements limitations to detect and localize fuel failures. Chemical and radiochemical techniques were critically proved. At the same time, a complete program of updating and optimization of those procedures was developed, including the revision of the analytical parameters, range of applicability and accuracy. A more adequate processing of data was adopted. They were compared with historical values corresponding to periods with and without fuel elements failures, used as references. The analysis of theoretical models of total gamma activity concentration and some specific radionuclides activity concentration evolution and their rates, and the comparison with experimental data obtained during normal operation including some failure events, generated tables of alarm criteria through a combination of parameters. Additionally, actions are suggested for different combination of parameters. Operative conditions that might interfere in the detection and localization of a failed fuel element are also pointed out. (Author)

(Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions)

Energy Technology Data Exchange (ETDEWEB)

Loveland, W.D.

1991-08-01

The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.

Application of the spectrometric and radiochemical techniques in analyzing environmental samples from the Bulgarian Black Sea region

International Nuclear Information System (INIS)

Veleva, B.S.; Mungov, G.; Galabov, N.; Kolarova, M.; Guenchev, T.

1999-01-01

Development of the appropriate methods and techniques for marine and atmospheric radioactivity measurements in the NIMH-BAS during the last 5 years is presented. Approaches for pre-concentration of the radionuclides from the atmosphere and sea water samples followed with reliable radiochemical methods for radionuclides separation and low level counting are discussed. Dissolved radiocesium concentrations measured in a period of time starting in 1993 show some decrease with years and spatial variations probably due to the hydrophysical features of the sampling sides - the lower measured concentrations during 1995 and 1998 correspond to the lower salinity. Application of the radiochemical separation of Plutonium, Thorium, 90 Sr and Americium on the samples from the Bulgarian Black Sea coastal region is reported. (author)

Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates

Directory of Open Access Journals (Sweden)

Ramesh N. Patel

2004-01-01

Full Text Available The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Chiral intermediates and fine chemicals are in high demand from both the pharmaceutical and agrochemical industries for the preparation of bulk drug substances and agricultural products. The enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities has been demonstrated. In this article, biocatalytic processes are described for the synthesis of chiral pharmaceutical intermediates.

Dual process theory and intermediate effect: are faculty and residents' performance on multiple-choice, licensing exam questions different?

Science.gov (United States)

Dong, Ting; Durning, Steven J; Artino, Anthony R; van der Vleuten, Cees; Holmboe, Eric; Lipner, Rebecca; Schuwirth, Lambert

2015-04-01

Clinical reasoning is essential for the practice of medicine. Dual process theory conceptualizes reasoning as falling into two general categories: nonanalytic reasoning (pattern recognition) and analytic reasoning (active comparing and contrasting of alternatives). The debate continues regarding how expert performance develops and how individuals make the best use of analytic and nonanalytic processes. Several investigators have identified the unexpected finding that intermediates tend to perform better on licensing examination items than experts, which has been termed the "intermediate effect." We explored differences between faculty and residents on multiple-choice questions (MCQs) using dual process measures (both reading and answering times) to inform this ongoing debate. Faculty (board-certified internists; experts) and residents (internal medicine interns; intermediates) answered live licensing examination MCQs (U.S. Medical Licensing Examination Step 2 Clinical Knowledge and American Board of Internal Medicine Certifying Examination) while being timed. We conducted repeated analysis of variance to compare the 2 groups on average reading time, answering time, and accuracy on various types of items. Faculty and residents did not differ significantly in reading time [F (1,35) = 0.01, p = 0.93], answering time [F (1,35) = 0.60, p = 0.44], or accuracy [F (1,35) = 0.24, p = 0.63] regardless of easy or hard items. Dual process theory was not evidenced in this study. However, this lack of difference between faculty and residents may have been affected by the small sample size of participants and MCQs may not reflect how physicians made decisions in actual practice setting. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

an intermediate moisture meat

African Journals Online (AJOL)

STORAGESEVER

2008-07-04

Jul 4, 2008 ... traditional SM muscle without compromising quality. ... technique is intermediate moisture food processing. ... Traditionally, most tsire suya producers use ..... quality of Chinese purebred and European X Chinese crossbred ...

THE INTERMEDIATE NEUTRON-CAPTURE PROCESS AND CARBON-ENHANCED METAL-POOR STARS

Energy Technology Data Exchange (ETDEWEB)

Hampel, Melanie [Zentrum für Astronomie der Universität Heidelberg, Landessternwarte, Königstuhl 12, D-69117 Heidelberg (Germany); Stancliffe, Richard J. [Argelander-Institut für Astronomie, University of Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Lugaro, Maria [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, H-1121 Budapest (Hungary); Meyer, Bradley S., E-mail: mhampel@lsw.uni-heidelberg.de [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978 (United States)

2016-11-10

Carbon-enhanced metal-poor (CEMP) stars in the Galactic Halo display enrichments in heavy elements associated with either the s (slow) or the r (rapid) neutron-capture process (e.g., barium and europium, respectively), and in some cases they display evidence of both. The abundance patterns of these CEMP- s / r stars, which show both Ba and Eu enrichment, are particularly puzzling, since the s and the r processes require neutron densities that are more than ten orders of magnitude apart and, hence, are thought to occur in very different stellar sites with very different physical conditions. We investigate whether the abundance patterns of CEMP- s / r stars can arise from the nucleosynthesis of the intermediate neutron-capture process (the i process), which is characterized by neutron densities between those of the s and the r processes. Using nuclear network calculations, we study neutron capture nucleosynthesis at different constant neutron densities n ranging from 10{sup 7}–10{sup 15} cm{sup -3}. With respect to the classical s process resulting from neutron densities on the lowest side of this range, neutron densities on the highest side result in abundance patterns, which show an increased production of heavy s -process and r -process elements, but similar abundances of the light s -process elements. Such high values of n may occur in the thermal pulses of asymptotic giant branch stars due to proton ingestion episodes. Comparison to the surface abundances of 20 CEMP- s / r stars shows that our modeled i -process abundances successfully reproduce observed abundance patterns, which could not be previously explained by s -process nucleosynthesis. Because the i -process models fit the abundances of CEMP- s / r stars so well, we propose that this class should be renamed as CEMP- i .

The MHD intermediate shock interaction with an intermediate wave: Are intermediate shocks physical?

International Nuclear Information System (INIS)

Wu, C.C.

1988-01-01

Contrary to the usual belief that MHD intermediate shocks are extraneous, the authors have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear steepening from a continuous wave. In this paper, he clarifies the differences between the conventional view and the results by studying the interaction of an MHD intermediate shock with an intermediate wave. The study reaffirms his results. In addition, the study shows that there exists a larger class of shocklike solutions in the time-dependent dissiaptive MHD equations than are given by the MHD Rankine-Hugoniot relations. it also suggests a mechanism for forming rotational discontinuities through the interaction of an intermediate shock with an intermediate wave. The results are of importance not only to the MHD shock theory but also to studies such as magnetic field reconnection models

HPLC-ICP-MS compared with radiochemical detection for metabolite profiling of H-3-bromohexine in rat urine and faeces

DEFF Research Database (Denmark)

Jensen, B.P.; Gammelgaard, B.; Hansen, S.H.

2005-01-01

H-3-Bromohexine was dosed to rats as a model compound to allow comparison of HPLC-ICP-MS detection on bromine to radiochemical detection in an in vivo drug metabolism study. Metabolite profiles were obtained in urine and faeces extracts. No influence of the methanol gradient on the bromine response...... was observed in the range of 18 - 75% methanol. The sensitivity obtained by HPLC- ICP-MS was almost two orders of magnitude better than on-line H-3 radiochemical detection. For ICP- MS, the limit of detection was calculated to be 69 nM Br ( injection volume 100 mu l), corresponding to an absolute limit...

Chemical yield determination for 59Ni, 63Ni and 56Fe in low and intermediate nuclear wastes by ICP-AES

International Nuclear Information System (INIS)

Franco, Milton B.; Santos Neto, Francisco C. dos; Reis Junior, Aluisio S.; Temba, Eliane S.C.; Monteiro, Roberto P.G.

2011-01-01

Iron and nickel are constituents of a wide range of metallic materials used in nuclear reactor construction and their corresponding activation products are often encountered in reactor-derived solid low and intermediate-level wastes. The most significant radioisotopes of iron and nickel, in terms of quantity and half life, are 55 Fe (t 1/2 =2.73y), 59 Ni (t 1/2 =7.6x10 4 y) and 63 Ni (t 1/2 =10 2 y) and they are activation products of stable iron and nickel. 59 Ni is an X-ray - emitting and 55 Fe and 63 Ni are β-particle-emitting radionuclides and so they are radionuclides of interest for the performance of assessment studies of waste storage or disposal. For their determination in the radioactive wastes is necessary to know the chemical yield for the radiochemical separation procedures prior analytical measurements. In this work Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) technique was used for this aim. Total nickel and iron in waste samples from nuclear power plants were determined before and after the radiochemical separation at specific wavelengths, 231.604 nm and 259.940 nm respectively. The chemical yields for nickel and iron recovery were around 82 % for iron and 59 % for nickel according the analytical methodology adopted. (author)

Radiochemical characterization and environmental radiological impact in tin and lead processing from cassiterite

International Nuclear Information System (INIS)

Garcia, Marcia Aparecida Antico

2009-01-01

The tin and lead industry located in Pirapora do Bom Jesus in the state of Sao Paulo, Brazil, is responsible for the production of about 7000 ton year-1 of tin and 350 ton year-1 of lead. The raw material used in this facility is cassiterite, which presents in its composition concentrations of natural radionuclides from the uranium and thorium series up to 660 kBq kg -1 and 450 kBq kg -1 , respectively. The smelting and refining processes may lead to concentrations of these radionuclides, mainly in the precipitated dust and in slag. In the operational process, intermediate refining and final slag are obtained and are stored in piles in open air. It is estimated that the amount of waste stored is about 600000 ton. This work aims to study the environmental radiological impact of the operation of this facility and to establish its Environmental Radiological Monitoring Program. In order to accomplish this task the content of radioactivity was determined in the raw material, products, byproducts, residue, deposition pond and exhausting systems. Although in the raw material the radionuclides from the uranium and thorium series are almost in equilibrium, during the processing this equilibrium is disrupted and the radionuclides migrate according to their chemical properties. Concentrations up to 31 kBq kg -1 for 238 U, 69 kBq kg -1 for 226 Ra, 2.5 kBq kg -1 for 210 Pb, 130 kBq kg -1 for 232 Th and 120 kBq kg -1 for 228 Ra were obtained in the slag. The environmental radiological impact was established by measuring the radionuclides in the critical compartments that is the ones that may cause exposure to the public. If the residue pile is considered, the critical pathways are the internal exposition from the dust inhalation and the water ingestion, due to re suspension and dispersion of the pile dust and groundwater contamination, respectively; and external exposure due to immersion in the radioactive cloud and soil contamination. For the emission of gaseous and particulate

Radiochemical determination and separation or total radium, 226Ra and 224Ra

International Nuclear Information System (INIS)

Suarez, J. A.; Gonzalez, J. A.; Pablo, M. A. de

1987-01-01

Radiochemical purification and separation of radium has been carried out and the determination of total radium solubilized in aqueous samples has been studied assuming that all the alpha emitters of the sample have their origin in the 226Ra and elements of its desintegration chain. Also, the activities of 22Ra and 226 Ra have been evaluated separately doing a measurement after the chemical separation of the radium and another one 10 days after. (Author) 9 refs

Radiochemical procedure for the determination of plutonium isotopes in powdered milk

International Nuclear Information System (INIS)

Taddei, M.H.T.; Silva, N.C.

2006-01-01

A radiochemical procedure for the determination of alpha-emitting isotopes of plutonium in powdered milk is proposed. The procedure involves sample dissolution (by HNO 3 and HClO 4 ), separation by ionic-exchange resin, electrodeposition and alpha-spectroscopy. In order to determine the chemical recovery, 242 Pu was employed as a tracer. A reference material (Marine Sediment IAEA 135) was analyzed to validate such procedure, and to show its reliability. Afterwards, some powdered milk, produced for international trade, was analyzed and chemical recovery was found to be around 95%. (author)

Caenorhabditis elegans HIM-18/SLX-4 interacts with SLX-1 and XPF-1 and maintains genomic integrity in the germline by processing recombination intermediates.

Science.gov (United States)

Saito, Takamune T; Youds, Jillian L; Boulton, Simon J; Colaiácovo, Monica P

2009-11-01

Homologous recombination (HR) is essential for the repair of blocked or collapsed replication forks and for the production of crossovers between homologs that promote accurate meiotic chromosome segregation. Here, we identify HIM-18, an ortholog of MUS312/Slx4, as a critical player required in vivo for processing late HR intermediates in Caenorhabditis elegans. DNA damage sensitivity and an accumulation of HR intermediates (RAD-51 foci) during premeiotic entry suggest that HIM-18 is required for HR-mediated repair at stalled replication forks. A reduction in crossover recombination frequencies-accompanied by an increase in HR intermediates during meiosis, germ cell apoptosis, unstable bivalent attachments, and subsequent chromosome nondisjunction-support a role for HIM-18 in converting HR intermediates into crossover products. Such a role is suggested by physical interaction of HIM-18 with the nucleases SLX-1 and XPF-1 and by the synthetic lethality of him-18 with him-6, the C. elegans BLM homolog. We propose that HIM-18 facilitates processing of HR intermediates resulting from replication fork collapse and programmed meiotic DSBs in the C. elegans germline.

Instant thin layer chromatography (ITLC) - the most true and convenient method for the determination of radiochemical purity of Tc-99m Labeled radiopharmaceuticals

International Nuclear Information System (INIS)

Anwar-Ul-Azim, M.; Ansari, M.I.H.

2007-01-01

Full text: Determination of radiochemical purity usually involves paper chromatography method or some column chromatography such as ion exchange or gel filtration technique. In this study, a modified chromatography method with thin-layer support called instant thin Layer chromatography (ITLC) was used for the measurement of radiochemical purity. The aim of the study was to present instant thin layer chromatography-Silica-Gel (ITLC-SG) technique as a fairly rapid , convenient and inexpensive system for the screening of radiochemical impurities of 99mTc-labeled radiopharmaceuticals resulting from physical , chemical and/or radiation decomposition. Materials and Methods: The experiment was carried out at the Institute of Nuclear Medicine and Ultrasound, Dhaka for a period of 10 months from August '05 to May '06. Radiochemical purity of seven types of 99mTc-labeled radiopharmaceuticals, namely 99mTc-DTPA,99mTc- MI I, 99m Tc - HDP, 99m Tc - DMSA, 99m Tc - Tetofosmin, 99mTc-Fyton and 99mTc-ECD were measured by the use of two solvent dual-instant thin layer chromatography systems. Commercially available instant thin layer chromatography plate ( 20cm x20cm) impregnated with silica gel (ITLC-SG: Merck, Germany) was used as a stationary phase for the measurement of radiochemical impurities.Acetone, Ethyl methyl ketone, chloroform and methanol were used to measure the amount of free pertechnetate in the labelled radiopharmaceuticals and 0.9% saline was used in all cases as solvent (Mobile phase) to measure the amount of the hydrolyzed-reduced technetium colloid. Results: The results showed that the measured radiochemical purity of 99mTc-DTPA, 99mTc-MIBI, 99mTc-HDP, 99mTc-DMSA, 99mTc-Tetofosmin, 99mTc-Fyton and 99mTc-ECD were acceptable for all the studied samples except two samples of 99mTc-MIBI, one sample of 99mTc-Fyton and two samples of 99mTc-ECD, where the measured radiochemical purity were not within the acceptable RCP limits of commonly used radiopharmaceuticals (RCP

Radiolabeling of anti-CD20 with Re-188 for treatment of non-Hodgkin's lymphoma: radiochemical control

International Nuclear Information System (INIS)

Dias, Carla R.; Osso Junior, Joao A.

2009-01-01

The development of tumor-selective radiopharmaceuticals is clinically desirable as a means of detecting or confirming the presence and location of primary and metastatic lesions and monitoring tumor response to (chemo)therapy. In addition, the application of targeted radiotherapeutics provides a unique and effective modality for direct tumor treatment. In this manner the radioimmunotherapy (RIT) uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. Antibody therapy directed against the CD20 antigen on the surface of B-cells is considered one of the first successful target-specific therapies in oncology. The radionuclide rhenium-188 ( 188 Re) is currently produced from the father nuclide tungsten-188 ( 188 W) through a transportable generator system. Because of its easy availability and suitable nuclear properties (EβMAX = 2.1 MeV, t 1/2 = 16.9 h, Eγ = 155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agent and could be conveniently utilized for imaging and dosimetric purposes. The purpose of this work is to show the radiochemical control of the optimized formulation (solution) and lyophilized formulation (kit) of labeled rituximab (anti-CD20) with 188 Re. Rituximab was reduced by incubation with 2-mercaptoethanol at room temperature. The number of resulting free sulfhydryl groups was assayed with Ellman's reagent. Radiochemical purity of 188 Re-rituximab was evaluated using instant thin layer chromatography-silica gel (ITLC-SG). Quality control methods for evaluation of radiochemical purity showed good labeling yield of the antibody. (author)

Radiochemical tools at the experimental lakes area (ELA) in Ontario, Canada

International Nuclear Information System (INIS)

Pfitzner, J.; Brunskill, G.

1998-01-01

Full text: For over 20 years, Canadian research scientists have used radiochemical tracers added to remote and pristine lakes to study physical, chemical, and biological processes that could not be easily quantified by other methods. Lakes have also been manipulated by experimentally altering the hydrological cycle, chemical composition, and species of fish in selected lakes, and using companion lakes as controls. Varying additions of organic carbon, N, and P have been done, and the exchange rate of carbon dioxide between the atmosphere and water was estimated using radon evasion rates from radium spikes in the lake water. Multinuclide spikes were done to follow the path of mine waste elements through the food chain and sediment accumulation. Lakes were experimentally acidified with HCl and HNO 3 and H 2 SO 4 to simulate acid rain, and to study natural buffering capacity of the hydrological cycle. Some of this research has been used to legislate pollution control in the St. Laurence Great Lakes and across Canada and USA. ELA research team spirit has survived several forest fires, bear attacks on the kitchen, massive cut-backs in funding and reduction in staff of Fisheries and Ocean Canada

Labeling of thymidine analog with an organometallic complex of technetium-99m for diagnostic of cancer: radiochemical and biological evaluation

International Nuclear Information System (INIS)

Santos, Rodrigo Luis Silva Ribeiro

2007-01-01

Thymidine analogs have been labeled with different radioisotopes due to their potential in monitoring the uncontrollable cell proliferation. Considering that the radioisotopes technetium-99m still keep a privileged position as a marker due to its chemical and nuclear properties, this dissertation was constituted by the developed of a new technique of labeling of thymidine analog with 99m Tc, by means of the organometallic complex. The aims of this research were: synthesis of the organometallic complex technetium-99m-carbonyl, thymidine labeling with this precursor, evaluation of stability, and radiochemical e biological evaluation with healthy and tumor-bearing animals. The preparation of the organometallic precursor, using the CO gas, was easily achieved, as well as the labeling of thymidine with this precursor, resulting itself a radiochemical pureness of ≥ 97% and ≥ 94%, respectively. Chromatography systems with good levels of trustworthiness were used, ensuring the qualification and quantification of the radiochemical samples. The result of in vitro testing of lipophilicity disclosed that the radiolabeled complex is hydrophilic, with a partition coefficient (log P) of -1.48. The precursor complex and the radiolabeled have good radiochemical stability up to 6 h in room temperature. The cysteine and histidine challenge indicated losses between 8 and 1 1 % for concentrations until 300 mM. The biodistribution assay in healthy mice revealed rapid blood clearance and low uptake by general organs with renal and hepatobiliary excretion. The tumor concentration was low with values of 0.28 and 0.18 %ID/g for lung and breast cancer, respectively. The results imply more studies in other tumor models or the modification of the structure of the organic molecule that act like ligand. (author)

Cyclotron production, radiochemical separation and quality control of platinum radiotracers for toxicological studies

International Nuclear Information System (INIS)

Bonardi, M.; Birattari, C.; Groppi, F.; Arginelli, D.; Gini, L.; Gallorini, M.

1998-01-01

The increasing concentration of Pt, Pd and Rh in the environment is mainly due to the release of these elements from the catalytic converters of the motorvehicles. This situation makes it necessary to carry out metallotoxicological experiments on both cell cultures and laboratory animals, in order to assess their impact on living organisms after a Long Term and Low Level Exposure (LLE). Both nuclear reactions nat Ir(p,xn) and nat Os(α,xn) were investigated in the energy range up to 45 MeV for protons and 38 MeV for alpha-particles, in order to optimize the irradiation parameters for the production of 188,189,191 Pt. Several sets of thin- and thick-target excitation functions were determined experimentally by cyclotron irradiation at both Milano and Ispra cyclotrons. This paper reports the irradiation parameters studied and adopted and two radiochemical procedures for the separation of radio-Pt from an Os target, as well as from ruthenium, iridium and gold impurities. These procedures were used to obtain very high specific activity Pt radionuclides in No Carrier Added (NCA) form. Radionuclidic, radiochemical and chemical purity measurements were carried out by the use of several techniques like γ-spectrometry, ion-exchange radio-chromatography, atomic absorption spectrometry and neutron activation analysis. (author)

Radiochemical neutron activation analysis based multi-elemental analysis of high purity gallium

International Nuclear Information System (INIS)

Tashimova, F.A.; Sadikov, I.I; Salimov, M.I.; Zinov'ev, V.G.

2006-01-01

Full text: Gallium is one of the widely used materials in semiconductor and optoelectronics industry. Gallium is used to produce infrared detectors, piezoelectric sensors, high- and low-temperature transistors for space and defense technology. One of the most important requirements for semiconductor materials of gallium compounds is an excessive high purity for layers and films. Information on impurities (type of an impurity, concentration, character of distribution) is important as for better understanding of the physical and chemical processes taking place in formed semiconductor structures and for the 'know-how' of devices on their basis. The object of this work is to develop radiochemical neutron activation technique for analysis of high purity gallium. Irradiation of 0.1 g of gallium sample in neutron flux of 5·10 13 cm -2 s -1 for 5 hours will result in induced activity of more than 10 8 Bq, due to 72 Ga radionuclide, half-life of which is 14.1 hours. Therefore to perform instrumental NAA of gallium long period (10 day) cooling is required, and high sensitive determination of elements producing short- and long-lived radionuclides (T 1/2 72 Ga. We have studied the behavior of gallium in extraction-chromatographic system 'TBP-HCl'. The experiments have shown that higher factor of distribution (D) and capacity on gallium can be achieved when 'TBP-4M HCl' system is used. However more than 10 trace elements have high D and thus they cannot be separated from 72 Ga. To resolve the problem and increase the number of separated trace elements we have used preliminary satisfaction of chromatographic column with tellurium, which has D higher than the most of elements in 'TBP-4M HCl' system and thus suppresses extraction of elements. Distribution profile of gallium along the column and elution curve of 25 trace elements have been measured. Chemical yields of separated elements measured by using radiotracers are more than 93%. On the basis of the carried out researches

Rapid radiochemical procedures for a process support laboratory

International Nuclear Information System (INIS)

Beals, D.M.

1998-01-01

An on-site mobile laboratory has been installed near a groundwater treatment facility, and rapid analytical procedures have been deployed for determining sample activity in the process support laboratory. The required analyses to support the remediation project include gross alpha/, gross nonvolatile beta, 90 Sr, 99 Tc, 137 Cs and total Ra (226 + 228). The present mission of the Savannah River Site (SRS), a US Department of Energy nuclear production facility, is one of nuclear waste stabilization and of environmental restoration and remediation. Because of previous practices of disposing low-level radioactive waste to seepage basins, some of the groundwater under the SRS has become contaminated with radioactive species. A water treatment facility has been installed to remediate the groundwater below the old F and H areas' seepage basins. Groundwater is pumped from the contaminated aquifer through a series of filtration, ion exchange, and reverse osmosis steps and when cleaned is reinjected back into the aquifer. Samples are pulled from various points in the treatment facility to ensure that the process is working as designed. In order to minimize turnaround time for these analyses, a process control station (i.e., a mobile on-site laboratory) has been installed at the F area water treatment unit, and rapid radioanalytical procedures have been deployed

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

Energy Technology Data Exchange (ETDEWEB)

Reeves, S; Plimer, I R [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1997-12-31

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

Energy Technology Data Exchange (ETDEWEB)

Reeves, S.; Plimer, I. R. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1996-12-31

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

International Nuclear Information System (INIS)

Reeves, S.; Plimer, I. R.

1996-01-01

This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs

On the presence of fictitious solar neutrino flux variations in radiochemical experiments

International Nuclear Information System (INIS)

Vladimirskii, B.M.; Bruns, A.V.

2004-01-01

The currently available data on solar neutrino flux variation in radiochemical experiments and Cherenkov measurements have so far defied a simple interpretation. Some of the results concerning these variations are indicative of their relationship to processes on the solar surface. It may well be that a poorly understood, uncontrollable factor correlating with solar activity indices affects the neutrino flux measurements. This factor is assumed to modulate the detection efficiency on different detectors in different ways. To test this assumption, we have analyzed all available radiochemical measurements obtained with the Brookhaven (1970-1994, 108 runs), GALLEX (1991-1997, 65 runs), and SAGE (1989-2000, 80 runs) detectors for possible instability of the detection efficiency. We consider the heliophysical situation at the final stage of the run, the last 7-27 days, when the products of the neutrino reaction with the target material had already been accumulated. All of the main results obtained previously by other authors were found to be reproduced for chlorine-argon measurements. The neutrino flux anticorrelates with the sunspot numbers only for an odd solar cycle. A similar behavior is observed for the critical frequencies of the E-ionosphere. The neutrino flux probably correlates with the A p magnetic activity index only for an even solar cycle. The predominance of a certain sign of the radial interplanetary magnetic field (IMF) in the last 14 (or 7) days of the run has the strongest effect on the recorded neutrino flux. The effect changes sign when the polarity of the general solar magnetic field is reversed and is most pronounced for the shortest runs (less than 50 days). The dependence of the flux on IMF polarity completely disappears if the corresponding index is taken for the first rather than the last days of the run. The IMF effect on the recorded neutrino flux was also found for short runs in the gallium-germanium experiment, but this effect for a given

Caenorhabditis elegans HIM-18/SLX-4 interacts with SLX-1 and XPF-1 and maintains genomic integrity in the germline by processing recombination intermediates.

Directory of Open Access Journals (Sweden)

Takamune T Saito

2009-11-01

Full Text Available Homologous recombination (HR is essential for the repair of blocked or collapsed replication forks and for the production of crossovers between homologs that promote accurate meiotic chromosome segregation. Here, we identify HIM-18, an ortholog of MUS312/Slx4, as a critical player required in vivo for processing late HR intermediates in Caenorhabditis elegans. DNA damage sensitivity and an accumulation of HR intermediates (RAD-51 foci during premeiotic entry suggest that HIM-18 is required for HR-mediated repair at stalled replication forks. A reduction in crossover recombination frequencies-accompanied by an increase in HR intermediates during meiosis, germ cell apoptosis, unstable bivalent attachments, and subsequent chromosome nondisjunction-support a role for HIM-18 in converting HR intermediates into crossover products. Such a role is suggested by physical interaction of HIM-18 with the nucleases SLX-1 and XPF-1 and by the synthetic lethality of him-18 with him-6, the C. elegans BLM homolog. We propose that HIM-18 facilitates processing of HR intermediates resulting from replication fork collapse and programmed meiotic DSBs in the C. elegans germline.

Radiochemical and thermal studies of the copper(II)-exchanged form of synthetic zeolite linde sieve A

International Nuclear Information System (INIS)

Banerjee, S.P.

1978-01-01

Synthetic zeolite Linde Sieve A displays a double ion-sieve action. Only small cations can penetrate the single 6-rings into the beta cages. The radiochemical and thermal studies of copper(II)-exchanges form of 4A shows evidence of hydrated copper(II) ions in the zeolite structure. (author)

Integral method of treatment of experimental data from radiochemical solar neutrino detectors

International Nuclear Information System (INIS)

Gavrin, V.N.; Kopylov, A.V.; Streltsov, A.V.

1985-01-01

An analysis is made of the statistical errors in solar neutrino detection by radiochemical detectors at different times of exposure. It is shown that short exposures (tau/sub e/ = one-half to one half-life) give minimal one-year error. The possibility is considered of the detection of the solar neutrino flux variation due to annual changes of the Earth-Sun distance. The integral method of treatment of the experimental data is described. Results are given of the statistical treatment of computer simulated data

Region based route planning - Multi-abstraction route planning based on intermediate level vision processing

Science.gov (United States)

Doshi, Rajkumar S.; Lam, Raymond; White, James E.

1989-01-01

Intermediate and high level processing operations are performed on vision data for the organization of images into more meaningful, higher-level topological representations by means of a region-based route planner (RBRP). The RBRP operates in terrain scenarios where some or most of the terrain is occluded, proceeding without a priori maps on the basis of two-dimensional representations and gradient-and-roughness information. Route planning is accomplished by three successive abstractions and yields a detailed point-by-point path by searching only within the boundaries of relatively small regions.

Radiochemical analysis of a wide range of 131I activities in water and milk using well-type germanium detector

International Nuclear Information System (INIS)

Xin Li; Bradt, C.J.; Umme-Farzana Syed; Abdul Bari; Torres, M.A.; Kimi Nishikawa; Khan, A.J.; Menia, T.A.; Semkow, T.M.; University at Albany, State University of New York, Rensselaer, NY

2017-01-01

We report a study of a fast radiochemical method to determine the activity of 131 I via the radiochemical recovery obtained with a 129 I tracer. Previous methods were valid for low levels of 131 I activities. In the new method, we developed a correction using the 29.7-keV X-ray peak from Xe, taking into consideration that this peak originates from both and 131 I decay. This enables quantitation of high levels of 131 I activity. Furthermore, for a very high 131 I activity, one can use the 39.6-keV gamma peak which is unique to 129 I. Combining both approaches enables quantitation of 131 I activities up to 200 times that of the 129 I recovery tracer. (author)

High radiochemical yield synthesis of [18F]FLT from 3'-O-nosylated thymidine and its 3-N-BOC-protected analogue

International Nuclear Information System (INIS)

Yoon, M. K.; Oh, S. J.; Ryu, J. S.; Moon, D. H.

2002-01-01

We synthesized 3'-O-nosylate and its 3-N-BOC-protected thymidine derivatives as two precursors for high radiochemical yield synthesis of [ 18 F]FLT and optimized [ 18 F]fluorination conditions. (5'-O-DMTr-2'-deoxy-3'-O-nosyl-β-D-threo-pentofuranosyl)thymidine and its s 3-N-BOD-protected analogue were prepared with 54% and 28% yield, respectively. After drying of [ 18 F]F-, 3'-O-nosylate(10-30 mg) or its 3-N-BOC-protected(11-34 mg) precursor was added to 500 μl of CH3CN, respectively. The mixtures were heated at 100-130 .deg. C for 5-30 min. For hydrolysis, 250-500 μl 1N HCl at 50 .deg. C for 5 min condition was used and 1.5ml of 2M sodium acetate was used for neutralization. Reaction mixture was purified by HPLC. The optimal [ 18 F]fluorination yield of 3'-O-nosylate precursor was 85±5.4% with 34 mg of precursor and a reaction time of 5 min at 130 .deg. C. For 3-N-BOC-protected analogue, [ 18 F]fluorination yield was 82±5.4% with 34 mg of precursor and a reaction time of 5 min at 110. deg. C. After HPLC purification, overall radiochemical yield using each precursors were 40±5.2% and 42±5.4% and radiochemical purity were 98±0.5% and 97±2.1% for two precursors, respectively. Preparation time was 60±10.5 min including HPLC purification for two precursors. From these two precursors, [ 18 F]FLT can be easily prepared with high radiochemical yield. 3-N-BOC-protected precursor required milder [ 18 F]fluorination conditions than 3'-O-nosylate precursor

Interrelation of technologies for RW preparation and sites for final isolation of the wastes from pyrochemical processing of SNF

Energy Technology Data Exchange (ETDEWEB)

Gupalo, V.S.; Chistyakov, V.N. [JSC - Design-Prospecting and Scientific-Research Institute of Industrial Technology -, Kashirskoye Highway, 33, Moscow 115409 (Russian Federation); Kormilitsyn, M.V.; Kormilitsyna, L.A. [JSC - State Scientific Center - Research Institute of Atomic Reactors -, Ulyanovsk region, Dimitrovgrad - 10, 433510 (Russian Federation)

2013-07-01

For the justification of engineering solutions and practical testing of the radiochemical component of the perspective nuclear power complex with on-site variant of nuclear fuel cycle (NFC), it is planned to establish a multi-functional research-development complex (MFCRC) for radiochemical processing of spent nuclear fuels (SNF) from fast reactors. MFCRC is being established at the NIIAR site, it comprises technological process lines, where innovation pyro-electrochemical and hydrometallurgical technologies are realized, with an option for closing the inter-chain material flows for testing the combined radiochemically converted materials. The technological flowchart for processing at the MFCRC is subdivided into 3 segments: -) complex of the lead operations for dismantling the fuel elements (FE) and fuel assemblies (FA), -) pyrochemical extraction flowchart for processing SNF, and -) hydrometallurgical flowchart for processing SNF. The engineered solutions for the management and disposition of the radioactive wastes from MFCRC are reviewed.

Comparison study among methodologies of planar chromatography for radiochemical control of technetium-99m

International Nuclear Information System (INIS)

Monteiro, Elisiane de Godoy

2012-01-01

Radiopharmaceuticals are substances that have radioisotopes in their composition. About 95% of the procedures performed in nuclear medicine use radiopharmaceuticals with diagnostic purposes, and the Lyophilized Reagents (LR) labeled with Technetium-99m ( 99 mTc), obtained from 99 Mo/ 99 mTc generator, are the most one used. Quality Control represents the set of assays to be performed to assure that the product is adequate to its purpose. An important feature to be evaluated in 99m Tc radiopharmaceuticals is the radiochemical purity (% RqP) to quantify free pertechnetate ( 99 mTcO 4 - ) and technetium colloidal (99mTcO 2 ) mainly by paper chromatography (PC), thin layer (TLC) and High Performance Liquid Chromatography (HPLC). The objective of this work was to perform the comparison among the radiochemical control methodologies of LR labeled with 99m Tc, described in the United States Pharmacopoeia (USP) and European Pharmacopoeia (EP) and those used by IPEN. 99m TcO 4 - eluate and DISIDA, DMSA, DTPA, EC, ECD, GHA, MIBI, MDP, PIRO, SAH and Sn Coloidal LR were provided by IPEN-CNEN/SP. TLC-cellulose, TLC-SG.TLC-SG reverse phase, HPTLC-cellulose, HPTLC-SG (Merck) and ITLC-SG (Pall Corporation), W1MM, W3MM, W17M e W31ET (Whatman) chromatographic plates were used. The measurement of the radioactivity was done in a Perkin Elmer Cobra D-5002 gamma counter. LR were labeled to obtain 55,0 MBq mL 1 (1,5 mCi mL 1 ) of final radioactive concentration. The % 99m TcO 4 - , % 99m TcO 2 and % RqP were determined up to 4 hour labeling. From 11 LR, only EC and GHA have no radiochemical control methods in USP and EP. In USP and/or EP, DTPA, MDP, PIRO, SAH and Sn Coloidal methods use ITLC-SG; IPEN uses this chromatography plate in DISIDA, EC, ECD, GHA, PIRO, MIBI and SAH. As ITLC-SG had been out of production (recommended in 40, 70 and 41% of the USP, EP and IPEN methodologies, respectively), it was necessary to search alternatives to replace ITLC-SG plate in the radiochemical control

Radiochemical analysis in the nuclear research establishment (KFA) Juelich, FRG

International Nuclear Information System (INIS)

Anon.

1975-01-01

KFA Juelich is one of the two great nuclear research centres of the Federal Republic of Germany. About 3700 employees including about 700 scientists are engaged in a great number of programs and projects belonging to six main fields of research and development: high temperature reactor and energy techniques; nuclear fusion; properties of materials; materials research; life and environment; methods. In the article the radiochemical analysis work of the former Central Institute of Analytical Chemistry and its two successors is described: activation analysis, application of tracer techniques, fission product analysis. Further on the irradiation facilities are described, a short survey is given on the instrumentation, and the future work is outlined. (T.G.)

15th radiochemical conference: Booklet of abstracts and conference programme

International Nuclear Information System (INIS)

John, J.; Benes, P.; Kucera, J.; Havela, L.; Bartonicek, B.; Vobecky, M.; Krizova, V.; Kopicka, K.; Prasil, Z.

2006-04-01

The conference was structured as follows: Opening plenary lectures (6 lectures); Topic 1 - radionuclides in the environment, radioecology (22 verbal presentations (VPs), 23 poster presentations (PPs)); Topic 2 - nuclear analytical methods (22 VPs, 32 PPs); Topic 3 - chemistry of actinide and transactinide elements (8 VPs, 10 PPs); Topic 4 - radiation chemistry (9 VPs, 5 PPs); Topic 5 - production and application of radionuclides (17 VPs, 6 PPs); Topic 6 - separation methods, speciation (21 VPs, 23 PPs); Topic 7 - chemistry of nuclear fuel cycle, radiochemical problems in nuclear waste management (20 VPs, 16 PPs); Topic 8 - nuclear methods in medicine, radiopharmaceuticals, and radiodiagnostics, labelled compounds (8 VPs, 7 PPs); and Panels (2 introductions). (P.A.)

Radiochemical methods for studying lipase-catalyzed interesterification of lipids

International Nuclear Information System (INIS)

Schuch, R.; Mukherjee, K.D.

1987-01-01

Reactions involving lipase-catalyzed interesterification of lipids, which are of commendable interest in biotechnology, have been monitored and assayed by radiochemical methods using 14 C-labeled substrates. Medium chain (C 12 plus C 14 ) triacylglycerols were reacted in the presence of an immobilized lipase from Mucor miehei and hexane at 45 0 C with methyl [1- 14 C]oleate, [1- 14 C]oleic acid, [carboxyl- 14 C]trioleoylglycerol, [1- 14 C]octadecenyl alcohol, and [U- 14 C]glycerol, each of known specific activity. The reactions were monitored and the rate of interesterification determined by radio thin layer chromatography from the incorporation of radioactivity into acyl moieties of triacylglycerols (from methyl oleate, oleic acid, and trioleoylglycerol), alkyl moieties of wax esters (from octadecenyl alcohol), and into glycerol backbone of monoacylglycerols and diacylglycerols (from glycerol). (orig.)

Radiochemical neutron activation analysis of gold in geochemical samples

International Nuclear Information System (INIS)

Zilliacus, R.

1983-01-01

A fast method for the radiochemical neutron activation analysis of gold in geochemical samples is described. The method is intended for samples having background concentrations of gold. The method is based on the dissolution of samples with hydrofluoric acid and aqua regia followed by the dissolution of the fluorides with boric acid and hydrochloric acid. Gold is then adsorbed on activated carbon by filtrating the solution through a thin carbon layer. The activity measurements are carried out using a Ge(Li)-detector and a multichannel analyzer. The chemical yields of the separation determined by reirradiation vary between 60 and 90%. The detection limit of the method is 0.2 ng/g gold in rock samples. USGS standard rocks and exploration reference materials are analyzed and the results are presented and compared with literature data. (author)

Radiochemical plasma salicylamide assay using ring-labeled tritiated salicylamide

Energy Technology Data Exchange (ETDEWEB)

Stella, V J; Varia, S A; Riedy, M

1979-05-01

A rat plasma salicylamide assay was developed using ring-labeled tritiated salicylamide, synthesized by reacting salicylamide with tritium oxide in the presence of heptafluorobutyric acid. The reaction yielded /sup 3/H-salicylamide of specific activity up to 8.41 mCi/mmole, 60% yield. Plasma containing /sup 3/H-salicylamide and its metabolites was extracted with a toluene-based scintillation fluid, which was subsequently counted. Specificity for free salicylamide was demonstrated by radiochemical and standard fluorescence plasma salicylamide level-time curves. Specificity resulted from nonextraction of the salicylamide sulfate and glucuronide metabolites. Sulfatase and beta-glucuronidase treatment allowed the analysis of plasma sulfate and glucuronide conjugates as free salicylamide. This procedure should be effective for the analysis of salicylamide and its metabolites in the presence of similar phenolic compounds.

Radiochemical separations of hafnium, tantalum, and germanium from tungsten and selenium irradiated by 14 MeV neutrons

International Nuclear Information System (INIS)

Blachot, J.; Benabed, A.; Herment, J.; Monnand, E.

1968-01-01

Radiochemical separations of Hf, Ta and Ge from W and Se respectively, after 14 MeV-neutron irradiation. A new isotope: 79 Ge with a half-live of 50 ± 5 s and emitter of a 230 keV γ transition is observed. (authors) [fr

Radiochemical determination of strontium-90 and cesium-137 in waters of the Pacific Ocean and its neighboring seas

International Nuclear Information System (INIS)

Borisenko, G.S.; Kandinskii, P.A.; Gedeonov, L.I.; Ivanova, L.M.; Petrov, A.A.

1987-01-01

Depending on the salinity of the water, two versions of strontium-90 and cesium-137 concentration from water samples are presented. Cesium-137 was concentrated by precipitating sparingly soluble mixed hexacyanoferrates (II), and strontium-90 by precipitating carbonates together with calcium. A scheme has been given for radiochemical analysis of the concentrates. Strontium-90 and cesium-137 contents in the waters of the Pacific Ocean and its neighboring seas have been determined by the radiochemical method described. The levels of radionuclide content in the water and atmospheric precipitations have been shown to be inter-related. Strontium-90 and cesium-137 contents in the surface water of the northwestern Pacific were found to be much lower in 1980 than in the early seventies. The area of technogenic radioactive pollution was found to persist in the region of the Columbia mouth into the Pacific Ocean

Radiochemical analysis of radio-nuclides in sea water collected near Bikini Atoll

Energy Technology Data Exchange (ETDEWEB)

Miyake, Y; Sugiura, Y

1955-01-01

A radiochemical analysis of sea water containing fission materials collected near Bikini Atoll in June, 1954, was performed. The sea water was boiled with hydrochloric acid, iron and lanthanum salts each 5 mg as Fe and La were added to it. They were precipitated as hydroxide, which was dissolved in hydrochloric acid and ferric chloride was extracted with ethyl ether. The remaining solution was evaporated to dryness and the residue was dissolved in hydrochloric acid. Using the latter solution the group separation was done with cation exchanger resins.

Radiochemical surveillance of KNK primary sodium

International Nuclear Information System (INIS)

Stamm, H.-H.; Stade, K.Ch.

1987-05-01

Radiochemical surveillance of the KNK primary sodium has been performed now for 15 years with 953 effective full-power days. The overflow method used for sodium sampling proved to be reliable. Different crucible materials have been used for different analytical tasks. The amount of radionuclides in the primary system has not given restrictions to plant operation at any time. On-line gamma spectroscopy on pipings and components of the primary circuits was accomplished in reactor downtimes. Activity depositions on the walls were dominated by Ta-182 after KNK I operation. Main deposited activities at KNK II were Mn-54 (fresh core) and after operation with failed fuel Cs-137, in cover gas areas together with Zn-65. Efficient experimental radionuclide traps for the removal of Mn-54, Zn-65 and Cs-137 from the primary coolant were tested successfully. The dose rates on primary pipes and components of KNK I and KNK II were lower by an order of magnitude compared to water-cooled reactors. This is in good agreement with experiences from LMFBR's in other countries. The resulting average yearly accumulated personal dose rate was 0.21 man-Sv at KNK, compared to 3.9 man-Sv at German light-water-cooled power reactors

Radiochemical studies on amorphous zirconium phosphate

Energy Technology Data Exchange (ETDEWEB)

Dyer, A; Moores, G E [Salford Univ. (UK). Dept. of Chemistry and Applied Chemistry

1981-01-01

Amorphous zirconium phosphate (ZrP) is used in some hemodialysis machines for the regeneration of dialysate. Its function is to adsorb ammonium ions formed by the pretreatment of urea by urease. It also adsorbs Ca, Mg and K ions but leaches phosphate ions which are then removed (along with F/sup -/ ions) by a bed of hydrous zirconium oxide. The sodium form of ZrP is used although other forms have been suggested for use. The work reported here describes some preliminary radiochemical studies on the mechanism of release of phosphate ions and its possible relationship to sodium ion-exchange. /sup 32/P labelled material (HHZrP) was used for elution experiments with deionized water and buffer solutions having the pH's 4.2, 7.0 and 9.2. Buffer solutions used were as supplied by BDH. Elution was at four different temperatures in the range 293 to 363/sup 0/C. In the second series of experiments HHZrP was suspended in a NaCl solution labelled with /sup 22/Na. From this, /sup 22/Na labelled ZrP (NaHZrP) was prepared and eluted in the same way as the HHZrP. Results are given and discussed.

Determination of chromium, cobalt and nickel in tissue samples by radiochemical activation analysis

International Nuclear Information System (INIS)

Reisell, A.; Lakomaa, E.L.

1983-03-01

A radiochemical neutron activation analysis method for the determination of chromium, cobalt and nickel in tissue samples. A radiochemical neutron activation analysis method for the determination of chromium, cobalt and nickel has been developed. The destruction device used consisted of a combined wet-ashing-distillation and ion-exchange system. Six samples could be treated at the same time. The samples were wet-ashed with H*L2SO*L4-H*L2O*L2 mixture. Volatile elements were distilled as bromide compounds with HBr*H-. The distillation residue in 8M HCl was passed through hydrated antimony pentoxide (HAP) in order to remove disturbing *H2*H4Na-activity and through a Dowex 2 x 8 column so as to retain *H6*H0Co (formed from *H5*H8Ni). Chromium was elutriated from the column and precipitated as Cr(OH)*L3 for the removal of disturbing *H3*H2P-activity. The standards and samples were treated in a similar manner each so that the yield determination is not necessarily needed. The yields by tracer experiments were (43 +- 5) % for Cr, (93 +- 4) % for Co and (88 +- 14) % for Ni. The precision and accuracy of the method were studied by using reference materials of the National Bureau of Standards (NBS) and the International Atomic Energy Agency (IAEA)

The design of a new radiochemical laboratory complex

International Nuclear Information System (INIS)

Lewis, A.G.

1984-01-01

A brief account is given of the history and scope of Amersham International plc in the manufacture of radiopharmaceuticals and other labelled organic compounds, and radioactive sources. Extra facilities were needed and a new site was found, and contracts placed for new radiochemical laboratories. The two new laboratories, which are described in some detail, are intended as follows: (a) a Medical Products building for the production of a range of diagnostic kits for use in the treatment of thyroid and other disorders, the main isotope used being iodine-125; and (b) the Chemical Products building, for the development and manufacture of a wide range of organic compounds, which are labelled with either tritium or carbon-14. Particular emphasis is given to the description of the air conditioning and ventilation systems, the open work benches, and the special ventilated enclosures, and the drainage system. Planning for maximum flexibility is also stressed. (U.K.)

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)

Top3 processes recombination intermediates and modulates checkpoint activity after DNA damage

DEFF Research Database (Denmark)

Mankouri, Hocine W; Hickson, Ian D

2006-01-01

Mutation of TOP3 in Saccharomyces cerevisiae causes poor growth, hyperrecombination, and a failure to fully activate DNA damage checkpoints in S phase. Here, we report that overexpression of a dominant-negative allele of TOP3, TOP3(Y356F), which lacks the catalytic (decatenation) activity of Top3......, the catalytic activity of Top3 is not required for DNA damage checkpoint activation, but it is required for normal S-phase progression after DNA damage. We also present evidence that the checkpoint-mediated cell cycle delay and persistence of X-shaped DNA molecules resulting from overexpression of TOP3(Y356F......) are downstream of Rad51 function. We propose that Top3 functions in S phase to both process homologous recombination intermediates and modulate checkpoint activity....

Radioanalytical Chemistry for Automated Nuclear Waste Process Monitoring

International Nuclear Information System (INIS)

Jay W. Grate; Timothy A. DeVol

2006-01-01

The objectives of our research were to develop the first automated radiochemical process analyzer including sample pretreatment methodology, and to initiate work on new detection approaches, especially using modified diode detectors

[Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions

International Nuclear Information System (INIS)

Loveland, W.D.

1991-08-01

The work described herein is part of a project involving the study of low energy ( 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ''best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon 129 Xe with 197 Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon 12 C with 197 Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated

Characterization of 16S rRNA Processing with Pre-30S Subunit Assembly Intermediates from E. coli.

Science.gov (United States)

Smith, Brian A; Gupta, Neha; Denny, Kevin; Culver, Gloria M

2018-06-08

Ribosomal RNA (rRNA) is a major component of ribosomes and is fundamental to the process of translation. In bacteria, 16S rRNA is a component of the small ribosomal subunit and plays a critical role in mRNA decoding. rRNA maturation entails the removal of intervening spacer sequences contained within the pre-rRNA transcript by nucleolytic enzymes. Enzymatic activities involved in maturation of the 5'-end of 16S rRNA have been identified, but those involved in 3'-end maturation of 16S rRNA are more enigmatic. Here, we investigate molecular details of 16S rRNA maturation using purified in vivo-formed small subunit (SSU) assembly intermediates (pre-SSUs) from wild-type Escherichia coli that contain precursor 16S rRNA (17S rRNA). Upon incubation of pre-SSUs with E. coli S100 cell extracts or purified enzymes implicated in 16S rRNA processing, the 17S rRNA is processed into additional intermediates and mature 16S rRNA. These results illustrate that exonucleases RNase R, RNase II, PNPase, and RNase PH can process the 3'-end of pre-SSUs in vitro. However, the endonuclease YbeY did not exhibit nucleolytic activity with pre-SSUs under these conditions. Furthermore, these data demonstrate that multiple pathways facilitate 16S rRNA maturation with pre-SSUs in vitro, with the dominant pathways entailing complete processing of the 5'-end of 17S rRNA prior to 3'-end maturation or partial processing of the 5'-end with concomitant processing of the 3'-end. These results reveal the multifaceted nature of SSU biogenesis and suggest that E. coli may be able to escape inactivation of any one enzyme by using an existing complementary pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

Study of performance characteristics of a radiochemical method to determine uranium in biological samples

International Nuclear Information System (INIS)

Puga, Maria J.; Cerchietti, Maria L.R.; Prudenzo, J.E.; Arguelles, Maria G.

2005-01-01

In this paper is described a methodology to calculate detection limit (Ld), quantification level (Lq) and minimum detectable activity (MDA) in a radiochemical method for determination of uranium in urine samples. The concentration is measured by fluorimetry and alpha gross activity using liquid scintillation counting (LSC). The calculation of total propagated uncertainty on a spike sample is presented. Furthermore, the major sources of uncertainty and percentage contribution in both measurements are assessed. (author)

Determination of heavy metal pollutants such as Hg, Zn, Se, Cd, and Cu in aquatic environment of Thana Creek by radiochemical thermal neutron activation analysis

International Nuclear Information System (INIS)

khan, S.Z.; Shah, P.K.; Ramani Rao, V.; Turel, Z.r.; Haldar, B.C.

1984-01-01

A rapid method has been developed for the radiochemical separation of Cu, As, Se, Hg, and Zn from thermal neutron irradiated environmental samples. The concentration of the elements in the environmental samples has been ascertained by radiochemical neutron activation analysis. The accuracy, precision and sensitivity of the method has been determined. The results of the analysis indicates the location of maximum pollution of the aquatic environment and the extent of pollution in the 5 locations of Thana Creek. 1 reference, 3 tables

Use of 236Pu and 242Pu as a radiochemical tracer for estimation of Pu in bioassay samples by fission track analysis

International Nuclear Information System (INIS)

Sawant, Pramilla D.; Prabhu, Supreetha P.; Kalsi, P.C.

2008-01-01

236 Pu and 242 Pu are routinely used as radiochemical yield monitors in India for bioassay monitoring of occupational workers by alpha spectrometry. Fission Track Analysis (FTA) is also being standardized for trace level determination of Pu in bioassay samples. The present study, reports the utility of 236 Pu and 242 Pu as radiochemical tracers in estimation of Pu in bioassay samples by FTA technique. The advantages of using 236 Pu tracer in FTA over 242 Pu as well as the interference caused due to presence of 241 Pu in the bioassay samples of occupational workers handling power reactor grade Pu is discussed. (author)

Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995

International Nuclear Information System (INIS)

Bartholomay, R.C.; Tucker, B.J.; Ackerman, D.J.; Liszewski, M.J.

1997-04-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95

A radiochemical NAA method for the determination of tin, barium, copper and antimony- role of tin as an indicator for gun shot residues

International Nuclear Information System (INIS)

Chattopadhyay, N.; Basu, A.K.; Tripathi, A.B.R.; Rao, M.S.; Anil Kumar, S.; Parthasarathy, R.; Mathur, P.K.

1998-01-01

Metallic tin being present as impurity and hardening agent of lead bullet/shot, is expected to play an important role in forensic ballistics in matching of bullet lead specimens for establishment of commonness of origin and also as an additional parameter for characterisation of Gun Shot Residue (GSR). 121 Sn is a suitable radioisotope for quantification of the element at ppm level if it is separated in highest radiochemical purity. A sequential Radiochemical Neutron Activation Analysis (RNAA) procedure for its simultaneous determination along with trace levels of Ba, Cu and Sb has been developed and its applications in forensic science are described. (author)

A new radiochemical assay for fructose-1,6-diphosphatase in human leucocytes

International Nuclear Information System (INIS)

Janssen, A.J.M.; Trijbels, F.J.M.

1982-01-01

Fructose-1,6-diphosphatase (D-fructose-1,6-diphosphate 1-phosphohydrolase, EC 3.1.3.11, FDPase) is one of the key enzymes of the gluconeogenic pathway. Measuring the activity both in the presence and in the absence of AMP yields the true FDPase activity, corrected for non-specific phosphatase activity. In this paper the authors introduce a new radiochemical assay for FDPase, based on the decarboxylating activity of 6-phosphogluconate dehydrogenase. One molecule [U- 14 C]fructose-1,6-diphosphate yields one molecule 14 CO 2 which can be captured in strongly basic solutions and counted in a liquid scintillation counter. (Auth.)

Fractionation of Cardiolite for clinical use: comparative evaluation of radiochemical purity by thin-layer and paper chromatography of 99mTc-hexakis-2-methoxy-isobutyl-isonitrile complex

International Nuclear Information System (INIS)

Albernaz, M.S.; Pantoja, M.R.; Martinho, M.J.R.; Fonseca, M.L.B.; Bernardo-Filho, Mario

1996-01-01

Twenty-five vials of the previous divided Cardiolite (technetium-99m-hexakis-2-metoxi-isobutyl-isonitrile) were evaluated immediately after labeling with technetium-99m and in 15 them the specific activity assurance was checked at hourly intervals up to 3 hours. Quality control assessment comprised instant thin-layer chromatography, as suggested by the manufacturer, compared to paper chromatography which is widely available and less expensive than the former. Among the 25 bottles, 21 had a radiochemical purity higher than 89%. The redistribution of the Cardiolite in small doses vacuum containers was a practical and reliable technique. The technetium-99m-isonitrile was a stable radiochemical compound thought the three hours period of observation and proved adequate for clinical use. When thin-layer and paper chromatography were compared there was no significant difference regarding radiochemical purity. (author)

Financial Intermediation and Economic Growth of Jordan 1964-1988

OpenAIRE

Magableh, Ali H.

1995-01-01

Until recently, the economics and financial literature placed little attention on the role that financial intermediation can play in accelerating the rate of economic development in less Developed Countries (LDCs). This has been changed now, however, where some instrumental role has been emphasised for financial intermediation in the process of economic development and growth. It is argued that an expansion of the financial system, size and intermediation in LDCs tends to increase the level o...

Validation of the FDG (18F) radiochemical purity assay by thin layer chromatography

International Nuclear Information System (INIS)

Leao, R.L.C.; Oliveira, M.L.; Nascimento, J.E.; Nascimento, N.C.E.S.

2013-01-01

All methodologies utilized in radiopharmaceutical industry should be validated in order to prove that they meet the requirements of analytical applications, ensuring the reliability of the results. At a radiopharmaceutical industry there is one challenge aspect: sometimes it is not possible use a stable standard to perform the validation analysis. In order to overcome this difficulty, the objective of this study was to suggest a validation protocol for these methodologies, based on the recommendations of RE n° 899/Agencia Nacional de Vigilancia Sanitaria (ANVISA), and prove its efficiency, performing the radiochemical purity validation test of FDG (18F), by TLC. To obtain the calibration curve, we suggested that the theoretical activity values should be determined using a dose calibrator, simultaneously of each analysis performed by TLC, for 5 hours. The method was linear (R 2 of 0.996), precise (CV% <5%) and accurate (96.85% < accuracy < 102.56%). In relation to the robustness test, our experiments evaluated the influence of the distance travelled by mobile phase, variations at mobile phase concentration and type of chromatographic plate (silica gel on glass or aluminium plates). The detection and quantification limits were determined (321.9 and 1065.6 kBq, respectively). As expected, this methodology was nonspecific, showing a slight spot corresponding to the FDM. The proposed protocol was efficient and the methodology tested was effective to determine the radiochemical purity of FDG (18F), in accordance to the limits recommended by ANVISA. (author)

Line broadening in multiphoton processes with a resonant intermediate transition

International Nuclear Information System (INIS)

Wang, C.C.; James, J.V.; Xia, J.

1983-01-01

The linewidth of the excitation spectrum for multiphoton ionization is found to be broadened much more severely than the cascade fluorescence originating from the resonant intermediate level. These results are due to the mutual effects of the ionizing and resonating transitions, which are not properly accounted for in perturbative treatments

Intermediate mass distribution of the dual resonance pomeron

International Nuclear Information System (INIS)

Chiu, C.B.; Matsuda, S.

1978-01-01

The intermediate mass distribution of the dual resonance pomeron is determined at the one-loop level and it is shown that the mass distribution obtained is remarkably similar to a suitably defined mass distribution in the dual multiperipheral model. Thus it is suggestive to identify the intermediate states of the dual resonance pomeron with multiperipheral processes. (Auth.)

Radiochemical neutron activation analysis of zirconium and zirconium-niobium alloys

International Nuclear Information System (INIS)

Tashimova, F.A.; Sadikov, I.I.; Salimov, M.

2004-01-01

Full text: Zirconium and zirconium-niobium alloys are used on nuclear technology, as fuel cladding of nuclear reactors. Their nuclear-physical, mechanical and thermophysical properties are influenced them matrix and impurity composition, therefore determination of matrix and impurity content of these materials is a very important task. Neutron activation analysis is one from multielemental and high sensible techniques that are widely applied in analysis of high purity materials. Investigation of nuclear-physical characteristics of zirconium has shown that instrumental variant NAA is unusable for analysis due to high radioactivity of a matrix. Therefore it is necessary carrying out radiochemical separation of impurity radionuclides from matrix. Study of the literature datum have shown, that zirconium and niobium are very well extracted from muriatic solution with 5% tributyl phosphineoxide (TBPO) solution in toluene and 0,75 M solution of di-2-ethyl hexyl phosphoric acid (HDEHP) in cyclohexanone. Investigation of these elements extraction in these systems has shown that more effective and selective separation of matrix radionuclides is achieved in HDEHP-3M HCI system. This system is also extracted and hafnium, witch is an accompanying element of zirconium and its high content prevented determination of other impurity elements in sample. Therefore we used extraction system HDEHP-3M HCl for analysis of zirconium and zirconium-niobium alloys in chromatographic variant. By measurement of distribution profile of a matrix and of elution curve of determined elements is established, that for effective separation of impurity and matrix radionuclides there is enough chromatographic column with diameter 1 cm and height of a sorbent layer 7 cm, thus volume of elute, necessary for complete elution of determinate elements is 35-40 ml. On the basis of the carried out researches the technique of radiochemical NAA of high purity zirconium and zirconium-niobium alloy, which allows to

Radiochemical determination of {sup 210} Pb and {sup 226}Ra in petroleum sludges and scales; Determinacao radioquimica de {sup 210} Pb e {sup 226}Ra em borras e incrustacoes de petroleo

Energy Technology Data Exchange (ETDEWEB)

Araujo, Andressa Arruda de

2005-07-01

The oil extraction and production, both onshore and offshore, can generate different types of residues, such as sludge, that is deposited in the water/oil separators, valves and storage tanks and scales, which form i the inner surface of ducts and equipment. Analyses already carried out through gamma spectrometry indicated the existence of high radioisotope concentration. However, radionuclides emitting low-energy gamma-rays, such as {sup 210} Pb, are hardly detected by that technique. Consequently, there is a need to test alternative techniques to determine this and other radionuclides from the {sup 238} U series. This work, therefore, focuses on the radiochemical determination of the concentration of {sup 210}Pb, and {sup 226} Ra in samples of sludge and scale from the oil processing stations of the UN-SEAL, a PETROBRAS unit responsible for the exploration and production of petroleum in Sergipe and Alagoas. The sludge and scale samples went through a preliminary process of extraction of oil, in order to separate the solid phase, where the largest fraction of the radioactivity is concentrated. After oil removal, the samples were digested using alkaline fusion as an option for dissolution. Finally, their activity concentration was determined for the samples of sludge and scales, using and alternative radiochemical method, which is based on ionic exchange. The activity concentration found for {sup 210}Pb varied from 1,14 to 507,3 kBq kg{sup -1}. The values for {sup 226}Ra were higher, varying from 4,36 to 3.445 kBq kg{sup -1}. The results for {sup 226}Ra were then compared with the ones found for the same samples of sludge and scales using gamma spectrometry. The results of the comparison confirm the efficiency of the methodology used int hi work, that is, radiochemical determination by means of ionic exchange. (author)

Quantitative radio-chemical separation of calcium, strontium and barium

International Nuclear Information System (INIS)

Dupuis, M.C.; Dupuis, M.; Le Nagard, M.; Michot, H.

1965-01-01

A method for separation of Ca 45 , Sr 89 and Ba 140 has been developed for the radiochemical determination of these isotopes in a solution of fission with a large concentration of mineral salts. After removal of most fission products by solvent extraction (TTA-MIBK) at different pH, the alkaline earths are extracted from the aqueous phase at pH 9. After recovery with diluted hydrochloric acid, the three elements are adsorbed on cationic resin Dowex 50 and eluted sequentially with ammonium α - Hydroxy iso-butyrate using gradient concentration and pH. Ca 45 and Sr 89 are measured by β - counting and Ba 140 by γ spectrometry. The chemical yield approximates 80 per cent for calcium, and 70 per cent for strontium and barium. The decontamination factor is 10 5 for most fission products. Four separations can be performed in twenty hours. (authors) [fr

Paleomagnetism and radiochemical age estimates for Late Brunhes polarity episodes

International Nuclear Information System (INIS)

Denham, C.R.; Anderson, R.F.; Bacon, M.P.

1977-01-01

Several reversed polarity magnetozones occur within deep-sea sediment core CH57-8 from the Greater Antilles Outer Ridge, within sediment of latest Pleistocene/Late Brunhes age. The uppermost reversed interval spanning 31 data points coincides with the X faunal zone of the Last Interglacial Period. Radiochemical dating of cores CH57-8 and KN25-4 has shown that all the reversed polarity magnetozones are significantly younger than the Brunhes/Matuyama boundary at 0.7 m.y.B.P. A variation of the excess 230 Th method was used, in which 210 Po and 238 U were the actual radionuclides measured. In a third core from the Mid-Atlantic Ridge, the 210 Po results were similar to those which others obtained earlier by direct 230 Th measurements. (Auth.)

Research reactor FR2 - 20 years chemical and radiochemical measurements

International Nuclear Information System (INIS)

Feuerstein, H.; Graebner, H.; Oschinski, J.; Hoffmann, W.; Beyer, J.

1986-09-01

The FR2 has been a D 2 O cooled and moderated research reactor with a thermal output of 44 MW. It was in operation from 1961 to 1981. Because of the operating conditions of the reactor, only a small number of routine measurements were performed. For these however special techniques had to be developed. During the 20 years of operation a number of special events occured or have been observed, sometimes with very amazing results, e.g. the 'aceton effect'. This report describes the chemical and radiochemical conditions of the reactor systems, as well as the results of the surveilance work. Not described are measurements for the many experiments. The last chapter gives in a short form a description of the most unusual events and observations. (orig.) [de

Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method

International Nuclear Information System (INIS)

Messaoudi, Mohammed; Begaa, Samir; Hamidatou, Lylia; Salhi, M'hamed

2018-01-01

The essential trace element selenium is a focus of attention due to its effects on human health, there being consequences of both its deficiency and excess. Due to the ultra-trace content of selenium, the neutron activation analysis method (NAA) is difficult to apply. We therefore made use of the radiochemical neutron activation analysis (RNAA) to determine Se at low level concentrations in several consumed food items in Algeria. A radiochemical procedure based on liquid-liquid separation was established in our laboratory. In this research we focused on the determination of selenium in two species of coffee: Arabica and Robusta. The accuracy of the method was assessed by analyzing the certified reference material NIST-SRM 1573a (tomato leaves). The results obtained show a selenium variation from 0.025 to 0.052 μg/g in coffee beans and an average yield of the separation of about 85%. The results of this study were compared with those obtained with samples from Brazilian, Caribbean, Indian and Kenyan coffee beans.

Validity limits of fuel rod performance calculations from radiochemical data at operating LWRs

International Nuclear Information System (INIS)

Zaenker, H.; Nebel, D.

1986-01-01

There are various calculational models for the assessment of the fuel rod performance on the basis of the activities of gaseous and volatile fission products in the reactor coolant. The most important condition for the applicability of the calculational models is that a steady state release of the fission products into the reactor coolant takes place. It is well known that the models are not applicable during or shortly after reactor transients. The fact that 'unsteady states' caused by the fuel defection processes themselves can also occur in rare cases at steady reactor operation has not been taken into account so far. A test of validity is suggested with the aid of which the applicability of the calculational models can be checked in any concrete case, and the misleading of the reactor operators by gross misinterpretation of the radiochemical data can be avoided. The criteria of applicability are the fission product total activity, the slope tan α in the relationship lg (R/sub i//B/sub i/) proportional to lg lambda/sub i/ for the gaseous and volatile fission products, and the activity of the nonvolatile isotope 239 Np. (author)

NMR-based approach to the analysis of radiopharmaceuticals: radiochemical purity, specific activity, and radioactive concentration values by proton and tritium NMR spectroscopy.

Science.gov (United States)

Schenk, David J; Dormer, Peter G; Hesk, David; Pollack, Scott R; Lavey, Carolee Flader

2015-06-15

Compounds containing tritium are widely used across the drug discovery and development landscape. These materials are widely utilized because they can be efficiently synthesized and produced at high specific activity. Results from internally calibrated (3)H and (1)H nuclear magnetic resonance (NMR) spectroscopy suggests that at least in some cases, this calibrated approach could supplement or potentially replace radio-high-performance liquid chromatography for radiochemical purity, dilution and scintillation counting for the measurement of radioactivity per volume, and liquid chromatography/mass spectrometry analysis for the determination of specific activity. In summary, the NMR-derived values agreed with those from the standard approaches to within 1% to 9% for solution count and specific activity. Additionally, the NMR-derived values for radiochemical purity deviated by less than 5%. A benefit of this method is that these values may be calculated at the same time that (3)H NMR analysis provides the location and distribution of tritium atoms within the molecule. Presented and discussed here is the application of this method, advantages and disadvantages of the approach, and a rationale for utilizing internally calibrated (1)H and (3)H NMR spectroscopy for specific activity, radioactive concentration, and radiochemical purity whenever acquiring (3)H NMR for tritium location. Copyright © 2015 John Wiley & Sons, Ltd.

Optimizing solid oxide fuel cell cathode processing route for intermediate temperature operation

DEFF Research Database (Denmark)

Ortiz-Vitoriano, N.; Bernuy-Lopez, Carlos; Ruiz de Larramendi, I.

2013-01-01

-priced raw material and cost-effective production techniques.In this work the perovskite-type La0.6Ca0.4Fe0.8Ni0.2O3 (LCFN) oxide has been used in order to optimize intermediate temperature SOFC cathode processing route. The advantages this material presents arise from the low temperature powder calcination......For Solid Oxide Fuel Cells (SOFCs) to become an economically attractive energy conversion technology suitable materials which allow operation at lower temperatures, while retaining cell performance, must be developed. At the same time, the cell components must be inexpensive - requiring both low...... (∼600°C) and electrode sintering (∼800°C) of LCFN electrodes, making them a cheaper alternative to conventional SOFC cathodes. An electrode polarization resistance as low as 0.10Ωcm2 at 800°C is reported, as determined by impedance spectroscopy studies of symmetrical cells sintered at a range...

Stationary and through-flow radiochemical detectors in cooperation with high performance liquid chromatography: Application in biochemistry

International Nuclear Information System (INIS)

Kehr, J.

1986-01-01

A review article is presented containing some original experimental data and discussing the usability of radiochemical detection of labelled compounds using high performance liquid chromatography. The stationary and through-flow types of detection are compared with respect to efficiency, chromatographic zone resolution, usability in biochemical research, and also to the current trends of development of liquid chromatography. (author). 3 figs., 1 tab., 19 refs

Fast analysis procedure of radiochemical coordinat uptake for methotrexate

International Nuclear Information System (INIS)

Caston, J.D.; Kamen, B.A.

1976-01-01

Under this invention, a radio-chemical analysis is submitted to determine the concentration of methotrexate or its equivalents in analysis in a biological medium. The amounts taken up of the labelled compound and the known concentrations of the unlabelled compound to be determined are radio-isotopically related to a first system containing a pre-determined amount of the labelled compound and a pre-determined amount of the unlabelled compound. In a second system, identical to the first, save that the sample of the biological medium to be analyzed takes the place of the unlabelled compound, the amount of labelled compound taken up is determined radio-isotopically. The concentration of the compound in the sample is then determined by correlation of the labelled compound uptake determined in the second system with the relation determined in the first system. The radio-isotopic relations and determinations may be made by direct and sequential analytical techniques [fr

Intermediate view reconstruction using adaptive disparity search algorithm for real-time 3D processing

Science.gov (United States)

Bae, Kyung-hoon; Park, Changhan; Kim, Eun-soo

2008-03-01

In this paper, intermediate view reconstruction (IVR) using adaptive disparity search algorithm (ASDA) is for realtime 3-dimensional (3D) processing proposed. The proposed algorithm can reduce processing time of disparity estimation by selecting adaptive disparity search range. Also, the proposed algorithm can increase the quality of the 3D imaging. That is, by adaptively predicting the mutual correlation between stereo images pair using the proposed algorithm, the bandwidth of stereo input images pair can be compressed to the level of a conventional 2D image and a predicted image also can be effectively reconstructed using a reference image and disparity vectors. From some experiments, stereo sequences of 'Pot Plant' and 'IVO', it is shown that the proposed algorithm improves the PSNRs of a reconstructed image to about 4.8 dB by comparing with that of conventional algorithms, and reduces the Synthesizing time of a reconstructed image to about 7.02 sec by comparing with that of conventional algorithms.

Application of radiochemical neutron activation and atomic absorption spectrometry methods for the study of nutrition-pollution interactions in children

Energy Technology Data Exchange (ETDEWEB)

Tran Bang Diep [Institute for Nuclear Science and Technique, VAEC, P.O. Box 5T-160, Hanoi (Viet Nam)]. E-mail: tranfbangdiepj@yahoo.com; Tran Dai Nghiep [Institute for Nuclear Science and Technique, VAEC, P.O. Box 5T-160, Hanoi (Viet Nam)]. E-mail: tdnghiep@vaec.gov.vn

2005-07-01

The application of radiochemical neutron activation analysis (RNAA) and atomic absorption spectrometry (AAS) is expected to aid in understanding and evaluating the effects of environmental pollution on the nutritional status of children already exposed to marginal malnutrition. Samples of placenta, of low-weight and control newborns groups, were collected for determination of nutritional elements and pollutants. The mean ratios of pollutants and nutrients such as Cd/Zn, Hg/Se and Pb/Ca were evaluated for both groups. All these ratios in the placenta of the low-weight newborns are higher than that of the healthy group. The degree of the nutrient-pollutant interaction is evaluated by quantity R, with mercury considered as the most active pollutant while calcium the most active nutrient among the involved elements in process of the interaction. (author)

Application of radiochemical neutron activation and atomic absorption spectrometry methods for the study of nutrition-pollution interactions in children

International Nuclear Information System (INIS)

Tran Bang Diep; Tran Dai Nghiep

2005-01-01

The application of radiochemical neutron activation analysis (RNAA) and atomic absorption spectrometry (AAS) is expected to aid in understanding and evaluating the effects of environmental pollution on the nutritional status of children already exposed to marginal malnutrition. Samples of placenta, of low-weight and control newborns groups, were collected for determination of nutritional elements and pollutants. The mean ratios of pollutants and nutrients such as Cd/Zn, Hg/Se and Pb/Ca were evaluated for both groups. All these ratios in the placenta of the low-weight newborns are higher than that of the healthy group. The degree of the nutrient-pollutant interaction is evaluated by quantity R, with mercury considered as the most active pollutant while calcium the most active nutrient among the involved elements in process of the interaction. (author)

AUTOMATED PROCESS MONITORING: APPLYING PROVEN AUTOMATION TECHNIQUES TO INTERNATIONAL SAFEGUARDS NEEDS

International Nuclear Information System (INIS)

O'Hara, Matthew J.; Durst, Philip C.; Grate, Jay W.; Devol, Timothy A.; Egorov, Oleg; Clements, John P.

2008-01-01

Identification and quantification of specific alpha- and beta-emitting radionuclides in complex liquid matrices is highly challenging, and is typically accomplished through laborious wet chemical sample preparation and separations followed by analysis using a variety of detection methodologies (e.g., liquid scintillation, gas proportional counting, alpha energy analysis, mass spectrometry). Analytical results may take days or weeks to report. Chains of custody and sample security measures may also complicate or slow the analytical process. When an industrial process-scale plant requires the monitoring of specific radionuclides as an indication of the composition of its feed stream or of plant performance, radiochemical measurements must be fast, accurate, and reliable. Scientists at Pacific Northwest National Laboratory have assembled a fully automated prototype Process Monitor instrument capable of a variety of tasks: automated sampling directly from a feed stream, sample digestion/analyte redox adjustment, chemical separations, radiochemical detection and data analysis/reporting. The system is compact, its components are fluidically inter-linked, and analytical results could be immediately transmitted to on- or off-site locations. The development of a rapid radiochemical Process Monitor for 99Tc in Hanford tank waste processing streams, capable of performing several measurements per hour, will be discussed in detail. More recently, the automated platform was modified to perform measurements of 90Sr in Hanford tank waste stimulant. The system exemplifies how automation could be integrated into reprocessing facilities to support international nuclear safeguards needs

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.)

Radiochemical neutron activation analysis for trace elements evaluation of human milk

International Nuclear Information System (INIS)

Gill, K.P.; Zaidi, J.H.; Ahmad, S.

2003-01-01

The principal objective pursued in this study is to establish the base-line data on the status of elemental composition in human milk from Pakistani subjects of Rawalpindi/Islamabad area. Radiochemical neutron activation analysis (RNAA) methodology was developed and successfully employed to determine the concentration of 18 minor and trace elements (essential, toxic and nonessential) in human milk. This methodology has significantly improved the detection limits of most of these elements due to suppression of Compton background. The data provide the base-line values of these elements in human milk of low- and medium-income group subjects of the region. The results obtained show good compatibility with the data reported by the WHO on elemental composition of human milk from different geological regions. (orig.)

Fast radiochemical procedure to measure neptunium, plutonium, americium and curium in environmental samples for application in environmental monitoring and in radioecology research

International Nuclear Information System (INIS)

Pimpel, M.; Schuettelkopf, H.

1984-01-01

A radiochemical method is described by which Np, Pu, Am and Cm in environmental samples can be determined. The transuranium elements are dissolved with acids out of the ashed material. Np/Pu is separated from Am/Cm by sequential extraction using TOPO/cyclohexane. The two fractions are radiochemically purified. Np-237, Pu-239+240, Pu-238 and Pu-236 as well as Am-243, Am-241, Cm-244 and Cm-242 are measured by alpha spectrometery. Pu-236, Am-243 and Np-239 are used to determine the respective yields. A fast method of Np-239 preparation is described. The chemical yields range from 60 to 90%. The detection limit attained per nuclide is 10 fCi/sample. 20 reference, 1 table

Development of robotic plasma radiochemical assays for positron emission tomography

International Nuclear Information System (INIS)

Alexoff, D.L.; Shea, C.; Fowler, J.S.; Gatley, S.J.; Schlyer, D.J.

1995-01-01

A commercial laboratory robot system (Zymate PyTechnology II Laboratory Automation System; Zymark Corporation, Hopkinton, MA) was interfaced to standard and custom laboratory equipment and programmed to perform rapid radiochemical analyses for quantitative PET studies. A Zymark XP robot arm was used to carry out the determination of unchanged (parent) radiotracer in plasma using only solid phase extraction methods. Robotic throughput for the assay of parent radiotracer in plasma is 4--6 samples/hour depending on the radiotracer. Robotic assays of parent compound in plasma were validated for the radiotracers [ 11 C]Benztropine, [ 11 C]cocaine, [ 11 C]clorgyline, [ 11 C]deprenyl, [ 11 C]methadone, [ 11 C]methylphenidate, [ 11 C]raclorpride, and [ 11 C]SR46349B. A simple robot-assisted methods development strategy has been implemented to facilitate the automation of plasma assays of new radiotracers

Altered Functional Subnetwork During Emotional Face Processing: A Potential Intermediate Phenotype for Schizophrenia.

Science.gov (United States)

Cao, Hengyi; Bertolino, Alessandro; Walter, Henrik; Schneider, Michael; Schäfer, Axel; Taurisano, Paolo; Blasi, Giuseppe; Haddad, Leila; Grimm, Oliver; Otto, Kristina; Dixson, Luanna; Erk, Susanne; Mohnke, Sebastian; Heinz, Andreas; Romanczuk-Seiferth, Nina; Mühleisen, Thomas W; Mattheisen, Manuel; Witt, Stephanie H; Cichon, Sven; Noethen, Markus; Rietschel, Marcella; Tost, Heike; Meyer-Lindenberg, Andreas

2016-06-01

Although deficits in emotional processing are prominent in schizophrenia, it has been difficult to identify neural mechanisms related to the genetic risk for this highly heritable illness. Prior studies have not found consistent regional activation or connectivity alterations in first-degree relatives compared with healthy controls, suggesting that a more comprehensive search for connectomic biomarkers is warranted. To identify a potential systems-level intermediate phenotype linked to emotion processing in schizophrenia and to examine the psychological association, task specificity, test-retest reliability, and clinical validity of the identified phenotype. The study was performed in university research hospitals from June 1, 2008, through December 31, 2013. We examined 58 unaffected first-degree relatives of patients with schizophrenia and 94 healthy controls with an emotional face-matching functional magnetic resonance imaging paradigm. Test-retest reliability was analyzed with an independent sample of 26 healthy participants. A clinical association study was performed in 31 patients with schizophrenia and 45 healthy controls. Data analysis was performed from January 1 to September 30, 2014. Conventional amygdala activity and seeded connectivity measures, graph-based global and local network connectivity measures, Spearman rank correlation, intraclass correlation, and gray matter volumes. Among the 152 volunteers included in the relative-control sample, 58 were unaffected first-degree relatives of patients with schizophrenia (mean [SD] age, 33.29 [12.56]; 38 were women), and 94 were healthy controls without a first-degree relative with mental illness (mean [SD] age, 32.69 [10.09] years; 55 were women). A graph-theoretical connectivity approach identified significantly decreased connectivity in a subnetwork that primarily included the limbic cortex, visual cortex, and subcortex during emotional face processing (cluster-level P corrected for familywise error =�

The deterioration of intermediate moisture foods

Science.gov (United States)

Labruza, T. P.

1971-01-01

Deteriorative reactions are low and food quality high if intermediate moisture content of a food is held at a water activity of 0.6 to 0.75. Information is of interest to food processing and packaging industry.

Application of the radiochemical - and the direct gamma ray spectrometry method to the burnup determination of irradiated uranium oxide

International Nuclear Information System (INIS)

Cunha, I.I.L.

1979-01-01

The burn up of natural U 3 O 8 that occurs by the action of thermal neutrons was determined, using the radioisotopes 144 Ce, 137 Cs, 103 Ru, 106 Ru and 95 Zr as monitors. The determination of the burn up was made using both destructive and non-destructive methods. In the non-destructive method, the technique of direct gamma-ray spectrometry was used and the radioisotopes mentioned were simultaneously counted in a Ge-Li detector. In the radiochemical method the same radioisotopes were isolated one from the other and from all other fission products before counting. The solvent extraction technique was used for the radiochemical separation of uranium, cerium, cesium and ruthenium. To separate zirconium and niobium, adsorption in silica-gel was used. The extraction agent employed to isolate cesium was dipycrilamine and for the separation of the other radioisotopes Di-(2-Ethyl Hexyl) Phosphoric acid (HDEHP) was used. (Author) [pt

Nd break-up process with considering 3NF at intermediate energies in a 3D approach

Energy Technology Data Exchange (ETDEWEB)

Radin, M., E-mail: harzchi@kntu.ac.ir; Ghasemi, H.

2016-01-15

In this work we have applied a three-dimensional approach to solve the three-nucleon Faddeev equation in the Jacobi momenta space. To this end, we have considered the inhomogeneous part of the Faddeev equation as an appropriate approximation for projectile intermediate energies. As an application the Bonn-B and the Tucson–Melbourne two- and three-nucleon forces have been used for calculating the differential cross section for proton–deuteron break-up process. Finally, comparing our results with the experimental data has been performed for 197 MeV and 346 MeV projectile energies.

Rapid and accurate determination of radiochemical purity of sup(99m)Tc compounds

International Nuclear Information System (INIS)

Tamat, S.R.

1977-01-01

The wide spread use of sup(99m)Tc-labelled radiopharmaceuticals and limitation of the short half-life of the isotope, is associated with an urgent need for a rapid, simple but accurate method for determining the radiochemical purity of the compound. A short paper chromatographic (KK) or thin layer chromatographic (KLT) method using 95% methanol or 0.9% saline solution as solvents, has solved the problem. With these methods, the amount of free sup(99m)Tc pertechnetate in a compound, can be determined in only a few minutes. These methods compare satisfactorily with lengtheir procedures. (author)

The SMC-5/6 Complex and the HIM-6 (BLM Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis.

Directory of Open Access Journals (Sweden)

Ye Hong

2016-03-01

Full Text Available Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs to generate crossovers (COs during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.

The SMC-5/6 Complex and the HIM-6 (BLM) Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis.

Science.gov (United States)

Hong, Ye; Sonneville, Remi; Agostinho, Ana; Meier, Bettina; Wang, Bin; Blow, J Julian; Gartner, Anton

2016-03-01

Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs) to generate crossovers (COs) during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC) family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM) during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.

Intermediate treatments

Science.gov (United States)

John R. Jones; Wayne D. Shepperd

1985-01-01

Intermediate treatments are those applied after a new stand is successfully established and before the final harvest. These include not only intermediate cuttings - primarily thinning - but also fertilization, irrigation, and protection of the stand from damaging agents.

Improved monitoring procedure for Iodine -131 in radiochemical process laboratory

International Nuclear Information System (INIS)

Singh, Pratap; Yadav, R.K.B.; Anilkumar, S.; Gopalakrishnan, R.K.; Chakraborty, S.

2016-01-01

Radiation Hazard Control Unit at Isotope wing provides radiological safety support and advises for safe processing and production of radiopharmaceuticals. Tellurium Oxide (TeO 2 ), irradiated in a nuclear reactor, is processed in a process laboratory for separating 131 I using dry distillation technique. The workplace environment is being assessed for airborne radioactivity using installed Static Air Samplers (SASs). SASs contains two filter media (glass fibre and charcoal impregnated paper) to collect airborne 131 I radioactivity and laboratory air sampled at 50 litres per minutes (lpm). Personal Air Sampler (PAS) consists of three types of filters viz. a glass fibre, charcoal impregnated paper and cartridges containing activated charcoal granules. Three combinations were studied at a sampling rate of 5 lpm

Cryo-EM structures of two bovine adenovirus type 3 intermediates

International Nuclear Information System (INIS)

Cheng, Lingpeng; Huang, Xiaoxing; Li, Xiaomin; Xiong, Wei; Sun, Wei; Yang, Chongwen; Zhang, Kai; Wang, Ying; Liu, Hongrong; Huang, Xiaojun; Ji, Gang; Sun, Fei; Zheng, Congyi; Zhu, Ping

2014-01-01

Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process

Cryo-EM structures of two bovine adenovirus type 3 intermediates

Energy Technology Data Exchange (ETDEWEB)

Cheng, Lingpeng; Huang, Xiaoxing; Li, Xiaomin [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Xiong, Wei [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Sun, Wei; Yang, Chongwen; Zhang, Kai; Wang, Ying [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Hongrong [College of Physics and Information Science, Hunan Normal University, Changsha, Hunan 410081 (China); Huang, Xiaojun; Ji, Gang; Sun, Fei [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Zheng, Congyi, E-mail: cctcc202@whu.edu.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Zhu, Ping, E-mail: zhup@ibp.ac.cn [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

2014-02-15

Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process.

A radiochemical procedure for the determination of Po-210 in environmental samples

International Nuclear Information System (INIS)

Godoy, J.M.; Schuettelkopf, H.

1980-07-01

A radiochemical procedure for the determination of Po-210 in environmental samples was developed. Soil, sediments, filter materials, plants, water and food samples can be analyzed for Po-210. Wet ashing is achieved with HNO 3 + H 2 O 2 or HCl + HNO 3 . To separate disturbing substances, a coprecipitation with Te is used for sample materials containing silica. Po-210 deposition from HCl solution on Ag platelets with other sample materials is possible directly. Deposited Po-210 is counted by α-spectrometry. For chemical yield determination Po-208 is added, yields range between 60% and 100%. A lower detection limit of about 0,002 pCi Po-210/sample is achievable. (orig./HP) [de

radiochemical study on the medically and technology radionuclides of some lanthanides

International Nuclear Information System (INIS)

Aglan, H.A.E.

2010-01-01

In this work, trials for the production of the medically and technologically interesting 139 Ce and 142 Pr radionuclides through cyclotron irradiations using protons and alpha particles were studied. The radiochemical separation of no-carrier-added cerium from proton irradiated lanthanum was studied by solvent extraction using DEE, TBP and TPPO, the latter reagent being employed for the first time for separation of radio cerium from bulk of lanthanum. Distribution coefficients of cerium and lanthanum were investigated as a function of equilibrium time and HNO 3 concentration. A mixture of 0.05 M K 2 Cr 2 O 7 and 0.1 M H 2 SO 4 was used as an oxidizing agent to improve the separation efficiency of cerium. A comparative study of the three extractants released that DEE is the best for separation of cerium from bulk of lanthanum oxide. The target was prepared by pressing. The production of 139 Ce of high radionuclidic and chemical purity via irradiation of lanthanum oxide target at MGC-20 cyclotron with protons of energy 14.5 is described. The experimental yield was found to be 153 kBq/μAh .The adsorption behaviour of La/Ce system on Dowex 50W-X8 in different media, namely, nitric acid, acetate buffer and citrate buffer was studied as a function of the concentration of nitric acid and buffer ph. In addition, in cation-exchange column chromatography experiments, three different eluants, namely, citrate buffer of ph 5.5, 0.1 M EDTA and 0.2 M α-HIBA, were employed for separation of Ce (III) from La (III). The optimum conditions for improvement of radiochemical separation of no-carrier-added 139 Ce from proton irradiated lanthanum were applied using the most suitable chelating agent 0.2 M α-HIBA. The purification of 139 Ce from macro amount of La (III) was done using two columns in a sequence. The experimental yield was found to be 200 kBq/μAh.

The reliability of radiochemical and chemical trace analyses in environmental materials

International Nuclear Information System (INIS)

Heinonen, Jorma.

1977-12-01

After theoretically exploring the factors which influence the quality of analytical data as well as the means by which a sufficient quality can be assured and controlled, schemes of different kinds have been developed and applied in order to demonstrate the analytical quality assurance and control in practice. Methods have been developed for the determination of cesium, bromine and arsenic by neutron activation analysis at the natural ''background'' concentration level in environmental materials. The calibration of methods is described. The methods were also applied on practical routine analysis, the results of which are briefly reviewed. In the case of Ce the precision of a comprehensive calibration was found to vary between 5.2-9.2% as a relative standard deviation, which agrees well with the calculated statistical random error 5.7-8.7%. In the case of Br the method showed a reasonable precision, about 11% on the average, and accuracy. In employing the method to analyze died samples containing Br from 3 to 12 ppm a continuous control of precison was performed. The analysis of As demonstrates the many problems and difficulties associated with environmental analysis. In developing the final method four former intercomparison materials of IAEA were utilized in the calibration. The tests performed revealed a systematic error. In this case a scheme was developed for the continuous control of both precision and accuracy. The results of radiochemical analyses in environmental materials show a reliability somewhat better than that occuring in the determination of stable trace elements. According to a rough classification, 15% of the results of radiochemical analysis show excellent reliability, whereas 60% show a reliability adequate for certain purposes. The remaining 15% are excellent, 60% adequate for some purposes and 30% good-for-nothing. The reasons for often insufficient reliability of results are both organizational and technical. With reasonable effort and

Automation of column-based radiochemical separations. A comparison of fluidic, robotic, and hybrid architectures

Energy Technology Data Exchange (ETDEWEB)

Grate, J.W.; O' Hara, M.J.; Farawila, A.F.; Ozanich, R.M.; Owsley, S.L. [Pacific Northwest National Laboratory, Richland, WA (United States)

2011-07-01

Two automated systems have been developed to perform column-based radiochemical separation procedures. These new systems are compared with past fluidic column separation architectures, with emphasis on using disposable components so that no sample contacts any surface that any other sample has contacted, and setting up samples and columns in parallel for subsequent automated processing. In the first new approach, a general purpose liquid handling robot has been modified and programmed to perform anion exchange separations using 2 mL bed columns in 6 mL plastic disposable column bodies. In the second new approach, a fluidic system has been developed to deliver clean reagents through disposable manual valves to six disposable columns, with a mechanized fraction collector that positions one of four rows of six vials below the columns. The samples are delivered to each column via a manual 3-port disposable valve from disposable syringes. This second approach, a hybrid of fluidic and mechanized components, is a simpler more efficient approach for performing anion exchange procedures for the recovery and purification of plutonium from samples. The automation architectures described can also be adapted to column-based extraction chromatography separations. (orig.)

A rapid, simple method for obtaining radiochemically pure hepatic heme

International Nuclear Information System (INIS)

Bonkowski, H.L.; Bement, W.J.; Erny, R.

1978-01-01

Radioactively-labelled heme has usually been isolated from liver to which unlabelled carrier has been added by long, laborious techniques involving organic solvent extraction followed by crystallization. A simpler, rapid method is devised for obtaining radiochemically-pure heme synthesized in vivo in rat liver from delta-amino[4- 14 C]levulinate. This method, in which the heme is extracted into ethyl acetate/glacial acetic acid and in which porphyrins are removed from the heme-containing organic phase with HCl washes, does not require addition of carrier heme. The new method gives better heme recoveries than and heme specific activities identical to, those obtained using the crystallization method. In this new method heme must be synthesized from delta-amino[4- 14 C]levulinate; it is not satisfactory to use [2- 14 C]glycine substrate because non-heme counts are isolated in the heme fraction. (Auth.)

Radiochemical investigations on the solubility of molybdatophosphate in phosphate determination

International Nuclear Information System (INIS)

Noack, S.

1975-01-01

The solubility of various molybdatophosphates was determined under the conditions of a gravimetric phosphate determination by radiochemical means by labelling PO 4 3- with P-32. Starting with various conditions for phosphate determination via the molybdatophosphate of quinoline, 8-hydroxyquinoline, dimorpholino ethane, N,N,N',N'-tetrakis-β-hydroxypropyl ethylene diamine and N,N,N',N'-tetrakis-β-hydroxybutyl ethylene diamine, a general working rule was developed to determine the solubility. Taking the example of quinoline molybdatophosphates, a series of influencing factors - work, concentration and measuring parameters - were investigated in order to be able to limit the reliability region of the gravimetric phosphate determination. Depending on the conditions, the measured solubilities were between 10 -10 and 10 -6 Mol/l, the corresponding degrees of precipitation between 99.0 and 99.9999%. Apparent solubility products were calculated for the different molybdatophosphates using computer programmes especially developed for this purpose. (orig./RB) [de

VHTR engineering design study: intermediate heat exchanger program. Final report

International Nuclear Information System (INIS)

1976-11-01

The work reported is the result of a follow-on program to earlier Very High Temperature Reactor (VHTR) studies. The primary use of the VHTR is to provide heat for various industrial processes, such as hydrocarbon reforming and coal gasification. For many processes the use of an intermediate heat transfer barrier between the reactor coolant and the process is desirable; for some processes it is mandatory. Various intermediate heat exchanger (IHX) concepts for the VHTR were investigated with respect to safety, cost, and engineering design considerations. The reference processes chosen were steam-hydrocarbon reforming, with emphasis on the chemical heat pipe, and steam gasification of coal. The study investigates the critically important area of heat transfer between the reactor coolant, helium, and the various chemical processes

Thermogravimetric control of intermediate compounds in uranium metallurgy

International Nuclear Information System (INIS)

Gasco Sanchez, L.; Fernandez Cellini, R.

1959-01-01

The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs

Direct processes in ion-atom collisions at intermediate and high energies

International Nuclear Information System (INIS)

Rodriguez Chariarse, V.D.

1990-01-01

This thesis deals with direct processes induced by Zp charge ion impact on one or two electron atoms and ions at intermediate energies. At a first step, a one-dimensional collision model is used in order to prove the different theoretical methods available to study collisions at such energy range, such as: perturbative and related variational principles, and distorted wave methods. The best description of both, symmetric and asymmetric collision type, is achieved by the distorted wave methods, particularly the ones using the exact impulsive wave function. As a next step, the appropriate formulations of the wave functions employed in the one-dimensional model to describe the real 3-dimensional Coulomb interaction case are examined by using the Eikonal and impulse hypothesis. In this way, the VPS and Eikonal wave functions are reviewed, and furtherly, the Eikonal form of the extended impulse wave function is derived. The Eikonal impulse approximation (EIA) is introduced. This is a distorted wave method using the Eikonal and extended impulse wave functions. The choice of the EIA prior version, i.e., the one using extended impulse wave function in the final channel for excitation is widely discussed and justified. (Author) [es

Investigation of Chemical and Radiochemical Fingerprints of Water Resources in Siwa Oasis, Western Desert, Egypt

International Nuclear Information System (INIS)

El-Sayed, S.A.; Allam, Kh.A.; Salama, M.H.; El Begawy, H.

2017-01-01

Water resources in Siwa oasis, Egypt; included the Nubian sandstone aquifer system (NSSAS), Tertiary carbonate aquifer system (TCAS) as well as springs and lakes. Existing chemical and radiochemical fingerprints of these resources in the central and western parts of the oasis were examined based on the analyses of 30 water samples collected in 2015. In each sample, the analyzed chemical and radioisotopic constituents were Cl"-, SO_4"2"- , CO_3"2"-, HCO"3 "-, Na"+, K"+, Ca"2"+ and Mg"2"+, Al, B, Ba, Cd, Co, Fe, Cu, Mn, Mo, Ni, Pb, Sr, V, Zn, Si and Cr, "2"2"6 Ra, "2"3"2Th and "4"0K. Other physical properties included ph and TDS were measured in the field. The chemical analysis was carried out following the ASTM methods, while the radiochemical measurements were done using a hyper pure germanium (HPGe) gamma ray spectrometry. Results of this work may be advantage ous to promote the hydrologic database in the oasis, where levels of the natural radioactivity in groundwater resources were established for the first time. Water resources were classified based on their contents of TDS into fresh water for the NSSAS, brackish to salty water for TCAS, brackish water for springs and brine water for lakes. The artesian water of the NSSAS and TCAS and water of the springs were alkaline, while the water of the lakes was acidic. Chemical characters of the ground water of the NSSAS reflected a little response to the processes of water-rock interactions, and the vice versa was observed for the groundwater of the TCAS. The ground water of the NSSAS was dominated by HCO"3"-Na genetic type characterizing the meteoric origin of water. The ground water of the TCAS was characterized by the presence of three genetic types of water (SO"4"-Na, Cl-Mg, and Cl-CA water), indicating the modification of the recharged water from the underlain NSSAS due to the effects of water sediment interactions and mixing with trapped ancient sea water. The chemical properties of spring water were, greatly

Application of radiochemical methods for development of new biological preparation designed for soil bioremediation

International Nuclear Information System (INIS)

Kim, A.A.; Djuraeva, G.T.; Djumaniyazova, G.I.; Yadgarov, Kh.T.

2006-01-01

developed complex of radiochemical methods allowed to determine the PCB-destructive activity of bacteria at initial screening, selection and investigation of strains of soil bacteria. Stability of the positive influence of biological preparations is defined by behaviour of introduced population in soil and by status of soil microbial community. We found the good survival rate of bacteria of genus Bacillus (up to 10 8 -10 9 cells / g of soil) from biological preparation which has been introduced in contaminated by HCCH and PCBs soil in dynamics during one year. Besides the introduction of association of active bacteria strains-destructors of organochlorine compounds in contaminated soil makes the positive effect on development of soil microflora - stimulates the development of the useful (ammonifiers, oligonutophiles, nitrogen fixers and actinomyces) and suppresses development of a harmful microflora (micromycetes). We found that microbial processes in the soil contaminated by organochlorine compounds proceeded more intensively at addition of biofertilizer. Hence, biofertilizer appeared suitable organic substrate for stimulation of introduced and natural microflora of contaminated soil. Thus artificial enrichment (introduction) of contaminated soils by the microbial preparation designed on the basis of associations of bacteria - destructors of pesticides can be perspective and economic way of elimination of residual amounts of organochlorine pesticides in soil. Biofertilizer can be recommended as additional organic substrate for stimulation of introduced and natural microflora of contaminated soils. The combined application of bacterial preparation and biofertilizer can be recommended as most efficient way for biodegradation of organochlorine compounds. (author)

Preparation of 35S-labelled albendazole sulfinyl (ABZO)

International Nuclear Information System (INIS)

Zhang Lufang; Wu Yuanfang; Yang Zhiming

1992-01-01

Albendazole is an important insecticide and albendazole sulfinyl (ABZO) is the effective component. In order to investigate its absorption, distribution and excretion in vivo, 35 S-labelled tracer was necessary for experiment. 35 S-labelled intermediate was made by isotopic exchange. The radiochemical yield was over 90%. After purification by TLC, the radiochemical purity of the 35 S-ABZO determined by PC and electrophoresis was over 95%

Preparation, radiochemical analysis and biodistribution of 99mTc-dihydrobis(1-pyrazolyl)borate

International Nuclear Information System (INIS)

Owunwanne, A.; Abdel-Dayem, H.; Yacoub, T.

1987-01-01

Optimum preparation of 99m Tc-dihydrobis(1-pyrazolyl)borate ( 99m Tc-HBPz 2 ) was done by mixing 1.4 mg/ml HBPz 2 and 1.0 mg/ml of stanous PYP. Radiochemical analysis of the preparation using paper chromatography (PC), thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) indicated a stable product with one major component. The labelling efficiency was approximately 90%. Animal biodistribution studies performed in mice showed that most of the injected radioactivity was confined to the liver, kidney, lungs, intestine and heart. The heart to blood ratio was small but persisted up to 3 hrs. after the injection. (orig.) [de

Solution-processed parallel tandem polymer solar cells using silver nanowires as intermediate electrode.

Science.gov (United States)

Guo, Fei; Kubis, Peter; Li, Ning; Przybilla, Thomas; Matt, Gebhard; Stubhan, Tobias; Ameri, Tayebeh; Butz, Benjamin; Spiecker, Erdmann; Forberich, Karen; Brabec, Christoph J

2014-12-23

Tandem architecture is the most relevant concept to overcome the efficiency limit of single-junction photovoltaic solar cells. Series-connected tandem polymer solar cells (PSCs) have advanced rapidly during the past decade. In contrast, the development of parallel-connected tandem cells is lagging far behind due to the big challenge in establishing an efficient interlayer with high transparency and high in-plane conductivity. Here, we report all-solution fabrication of parallel tandem PSCs using silver nanowires as intermediate charge collecting electrode. Through a rational interface design, a robust interlayer is established, enabling the efficient extraction and transport of electrons from subcells. The resulting parallel tandem cells exhibit high fill factors of ∼60% and enhanced current densities which are identical to the sum of the current densities of the subcells. These results suggest that solution-processed parallel tandem configuration provides an alternative avenue toward high performance photovoltaic devices.

Radiochemical and thermal studies of the cation-exchanged forms of synthetic zeolite Linde sieve A

Energy Technology Data Exchange (ETDEWEB)

Banerjee, S P [Saugar Univ. (India). Dept. of Chemistry

1976-02-01

The compositions of the cobalt and silver-exchanged forms of synthetic zeolite Sieve A have been determined by radiochemical and TGA studies and correspond to Co/sub 6/A.19.8H/sub 2/O and Ag/sub 12/..cap alpha... 20H/sub 2/O respectively (A=Al/sub 12/Si/sub 12/O/sub 48//sup 12/-). Heating of these zeolites inhibits their capacity for cation exchange and water absorption. No evidence of occluded NaAlO/sub 2/ has been found.

Development of a radiochemical sensor. Part I: Feasibility study

Energy Technology Data Exchange (ETDEWEB)

Tarancon, A. [Departament de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, C/ Marti Franques 1, 08028 Barcelona (Spain); Garcia, J.F. [Departament de Pintura, Facultat de Belles Arts, Universitat de Barcelona, C/ Pau Gargallo 4, 08028 Barcelona (Spain)]. E-mail: jfgarcia@apolo.qui.ub.es; Rauret, G. [Departament de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, C/ Marti Franques 1, 08028 Barcelona (Spain)

2005-05-04

The evolution of nuclear activities and criteria for radiation protection have led to a continuous increase in measures to monitor and control the environment and therefore in the number of determinations required for such purposes. Classical analytical procedures are time-consuming, labor-intense and generate a large amount of waste. The alternative use of sensors for such determinations has seen very limited development. The present study focuses on the evaluation of the behavior of a prototype radiochemical sensor for liquid effluents. The sensor is based on a receptor made of a plastic scintillator and is capable of continuous, on-time and accurate remote quantification of the activity of alpha, beta and beta-gamma emitters. Low-level active solutions of {sup 90}Sr/{sup 90}Y, {sup 238}Pu, {sup 134}Cs and {sup 60}Co in matrices of groundwater, seawater and drinking water were quantified with prediction errors lower than 10% in most cases. The study also yields information about light generation and transmission and transductor configuration that will be useful in the design of future versions of this sensor.

A general approach to the construction of 'very accurate' or 'definitive' methods by radiochemical NAA and the role of these methods in QA

International Nuclear Information System (INIS)

Dybczynski, R.

1998-01-01

Constant progress in instrumentation and methodology of inorganic trace analysis is not always paralleled by improvement in reliability of analytical results. Our approach to construction of 'very accurate' methods for the determination of selected trace elements in biological materials by RNAA is based on an assumption that: (i) The radionuclide in question should be selectively and quantitatively isolated from the irradiated sample by a suitable radiochemical scheme, optimized with respect to this particular radionuclide, yielding finally the analyte in the state of high radiochemical purity what assures interference-free measurement by gamma-ray spectrometry. (ii) The radiochemical scheme should be based on ion exchange and/or extraction column chromatography resulting in an easy automatic repetition of an elementary act of distribution of the analyte and accompanying radionuclides between stationary and mobile phases. (iii) The method should have some intrinsic mechanisms incorporated into the procedure preventing any possibility of making gross errors. Based on these general assumptions, several more specific rules for devising of 'very accurate' methods were formulated and applied when elaborating our methods for the determination of copper, cobalt, nickel, cadmium, molybdenum and uranium in biological materials. The significance of such methods for Quality Assurance is pointed out and illustrated by their use in the certification campaign of the new Polish biological CRMs based on tobacco

Determination of radiochemical purity and pharmacokinetic parameters of sup(99m)Tc-sulphur colloid and sup(99m)Tc-tin colloid

International Nuclear Information System (INIS)

Jovanovic, V.; Konstantinovska, D.; Milivojevic, K.; Bzenic, J.

1981-01-01

Labelling yield and radiochemical purity, higher than 95%, of sup(99m)Tc-colloid preparations were determined by using the paper chromatography method. Less than 3% of labelled citric acid, added to the preparation as a buffer solution, has been found in sup(99m)Tc-sulphur colloid. High radiochemical purity and optimum size of colloid particles has also been proved by biodistribution studies on experimental animals. The analysis performed has shown that more than 50% of sup(99m)Tc-colloid preparations excreted by urine is sup(99m)TcO - , the remaining past 50% being protein bound sup(99m)Tc. Biological half-time of excretion of the fast phase is the same for both preparations, i.e. 10 min, while for the slow component it is 120 min in sup(99m)Tc-S-colloid and 160 min in sup(99m)Tc-Sn colloid. (orig.) [de

Radiochemical study on preparation and quality control of 1-125/1-131 labelled some organic compounds for medical uses

International Nuclear Information System (INIS)

El-azoney, K.M.S.E.

1997-01-01

The main objective of this thesis is to investigate the optimum condition for the radioiodination of some organic compounds which find wide applications in nuclear medicine. Iodine-131 (T 1 /2= 8.04 d) which is of great importance in the field, are used for this purpose. long chain fatty acids such as 16-Bromo-hexadecanoic (16-brHDA) and -phenyl -fatty acids such as 15-p-iodophenyl pentadecanoic acid (p-IPPA) will be used as model substrates. 1- Labelling of 16-Br-HDA with Na 131 I. Labelling of 16-BrHDA will be investigated via the non-isotopic exchange between 16-Br HDA and Na 131 I to give 16- 131 IHDA. In order to obtain a high radiochemical yield with high radiochemical purity for the product 16- 131 IHDA, simple and fast methods will be followed. The influence of reagents concentrations, time, temperature, solvents and four quaternary ammonium salts as phase transfer catalysts with only one crown ether will be studied. The determination of reaction velocities and activation energies of catalysed systems was effected and compared with results on the dry state system. 2- Labelling of p-Ipa with Na 131 I. Radioiodination of 15-p-iodophenyl pentadecanoic acid is investigated by the nucleophilic substitution reaction via the isotopic exchange between p-Ipa and Na 131 I. As with 16-BrHDA, factors affecting the labelling yield such as reagent concentrations, solvents, reaction time, temperature and catalyst, is examine. The effect of different temperatures on the radiochemical yield of P- 131 Ipa is studied to determine the activation energy of the exchange reaction. Because of the necessity to separate the iodinated products from the starting materials, high performance liquid chromatographic techniques were applied for this purpose. 3.15 figs., 3.2 tabs., 179 refs

Assessment of radiochemical purity of [18F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

International Nuclear Information System (INIS)

Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z.

2011-01-01

The quality control of [ 18 F]fludeoxyglucose ( 18 FDG) has received attention due to its increasing clinical use. Although the quality requirements of 18 FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of 18 FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. 18 FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of 18 FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of 18 FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of 18 FDG, considering operational conditions of our laboratory. (author)

An analysis of the changes on intermediate products during the thermal processing of black garlic.

Science.gov (United States)

Yuan, Heng; Sun, Linjuan; Chen, Min; Wang, Jun

2018-01-15

The thermal processing of black garlic was simulated. Fresh garlic was incubated at 55°C with 80% humidity and sampled every 5 or 10days. The changes in relevant products were as follows: the fructan content was decreased by 84.79%, and the fructose content was increased by 508.11%. The contents of Maillard reaction intermediate products were first increased and then decreased. The colour of garlic gradually became dark and the pH decreased from 6.13 to 4.00. By analyzing these changes, the mechanism of black garlic formation and the changes on the Maillard reaction were revealed. The sweetness of black garlic resulted mainly from the fructose that was produced, and the black colour was largely due to the Maillard reaction between fructose/glucose and amino acids. An understanding of this process is useful to explain the formation mechanism of black garlic and could lead to better control of the quality of black garlic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization, validation and standardization of a method of measuring the radiochemical purity of 99mTc-HMDP in Necker hospital

International Nuclear Information System (INIS)

Dumont, A.; Izembart, M.; Barritault, L.

1997-01-01

By the end of 1996, the tests of the radiochemical purity (RCP) of preparation of HMDP- 99m Tc at Necker hospital were effected by means of 'Tech-Kit' technique which allowed making evident only one radiochemical impurity, the free TcO 4 - . So, the aim of this work has been the search for another technique able to detect also the reduced hydrolyzed 99m Tc, and then, to optimize, validate and standardize this new technique. Several methods have been tested and compared on different points (the chemical species identified, practical difficulties, duration, reproducibility) in order to chose 'the best' one, consisting in associating two TLC (migration time, 3 minutes): - TLC no.1, ITLC-SG/Methyl-ethyl-ketone; - TLC no.2, ITLC-SG/1M Sodium acetate. This method has been subsequently: - optimized, concerning the quantity of deposed sampling, way of deposit drying, migration range, reading protocol by radio-chromatograph; - validated, by verifying the migration of radiochemical impurities by means of controls and by evaluating its sensitivity; - standardized, by defining the interest zones for interpreting the radio-chromatograms, by evaluating the reproducibility and by calculating the 'normal values' of RCP percentages. This method has been adopted as routine and with current recoil (40 preparations) and our conditions of realizations, the extreme values of the percentages obtained for the impurity zones of interests, have been the following: - TcO 4 - zone, [0.39%-1.07%]; - hydrolyzed reduced Tc zone, [0.96%-5.09%]. By taking into account their distribution we calculated a minimum RCP value of 94% to accept the preparation (the RCP being defined as equal to 100% - % TcO 4 - % hydrolyzed reduced Tc)

Trace element evaluation of different varieties of chewing gum by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Zaidi, J.H.; Arif, M.; Fatima, I.; Ahmad, S.; Qureshi, I.H.

2000-01-01

Extensive use of chewing gums, by children in particular, entails the evaluation of trace element contents in them. Radiochemical neutron activation analysis (RNAA) was successfully employed to determine the concentration of 35 trace elements (essential, toxic and nonessential) in eight different brands of chewing gum generally consumed in Rawalpindi/Islamabad area. Comparison of trace element data of our work with literature has been presented. None of the elements detected in the brands of chewing gum examined was found to be present at a level representing a substantial contribution to the total dietary intake of the element. (author)

Radiochemical method for evaluating the effect of antibiotics on Escherichia coli biofilms

International Nuclear Information System (INIS)

Dix, B.A.; Cohen, P.S.; Laux, D.C.; Cleeland, R.

1988-01-01

A simple radiochemical method for evaluating the action of antibiotics on Escherichia coli cells in biofilms is reported. After growth, biofilms of E. coli ATCC 25922 on disks of urinary catheter material were suspended in fresh medium containing or lacking an antibiotic, incubated for 4 h at 37 degrees C, and pulse-labeled with [ 3 H]leucine for 5 min. Radioactivity in trichloracetic acid-precipitable material in the biofilm and in the surrounding medium (planktonic E. coli) was then measured. Antibiotic-induced inhibition of incorporation of [ 3 H]leucine into the cells in the biofilm was far less pronounced than incorporation into planktonic cells and, furthermore, correlated well with loss in viable counts. The method is simple, inexpensive, and extremely timesaving

Intermediate-Mass Black Holes

Science.gov (United States)

Miller, M. Coleman; Colbert, E. J. M.

2004-01-01

The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

SCAN- a maintenance-free flowrate meter with direct digital read-out for computerised control applications in radiochemical plants

Energy Technology Data Exchange (ETDEWEB)

Shah, B V; Siddiqui, I A; Theyyunni, T K [Process Engineering and Systems Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

In radiochemical plants, the choice of flowrate sensor is subject to stringent requirements of fail-safe design and freedom from maintenance. The SCAN remote digital direct indicating flowrate meter described in this paper was developed to meet the requirements of flowrate and transmitting it to the control room, and to a computerised control system. SCAN is designed on the principle that flowrate through an orifice is a function of the head of liquid acting upon it. SCAN consists of a small chamber which receives the flow, and discharges it through an orifice located in bottom. The level of liquid in the pot represents the flowrate of the input stream. SCAN has been developed into an accurate, rugged and practical device by refinements in the design of internals, and by introducing a special end-section which makes the calibration insensitive to location. An important feature of SCAN is that it is passive, maintenance free, fail-safe device and contains no moving parts. There is no liquid hold up in the SCAN when idle, which is a desirable feature for the radiochemical plant environment. (author). 3 figs., 2 tabs.

Radiochemical studies, pre-clinical investigation and preliminary clinical evaluation of "1"7"0Tm-EDTMP prepared using in-house freeze-dried EDTMP kit

International Nuclear Information System (INIS)

Das, Tapas; Shinto, Ajit; Kamaleshwaran, Koramadai K.; Sarma, Haladhar D.; Mohammed, Sahiralam Khan; Mitra, Arpit; Lad, Sangita; Rajan, M.G.R.; Banerjee, Sharmila

2017-01-01

The objective of the present work is to formulate "1"7"0Tm-EDTMP using an in-house freeze-dried EDTMP kit and evaluate its potential as a bone pain palliation agent. Patient dose of "1"7"0Tm-EDTMP was prepared with high radiochemical purity using the lyophilized kit at room temperature within 15 min. Pre-clinical evaluation in normal Wistar rats revealed selective skeletal accumulation with extended retention. Preliminary clinical investigation in 8 patients with disseminated skeletal metastases exhibited selective uptake in the bone and retention therein for a long duration. - Highlights: • Formulation of patient dose of "1"7"0Tm-EDTMP using freeze-dried EDTMP kit. • Radiochemical studies and pre-clinical evaluation of the agent in animal model. • Clinical evaluation in eight cancer patients with disseminated skeletal metastases.

Radiochemical purity and in vitro stability of Tc-99m radiopharmaceuticals

International Nuclear Information System (INIS)

Vucina, J.

2001-01-01

The increased contents of long lived 99 Tc, oxygen and cupric ions could affect the labeling yield of eight radiopharmaceuticals. Oxygen and in leaser extend copper were found to affect the radiochemical purity of the preparations. In vitro stability of radiopharmaceuticals, examined on 99m Tc(Sn)-pyrosphoshate solutions, was extended when ascorbic acid was added as the chemical stabilizer. The quantity of 5x10 -7 mol/dm 3 of ascorbic acid was found to be sufficient to keep the content of 99m Tc-pertechnetate below 1 % six hours after labeling even in the cases when 99m Tc was present in high radioactive concentrations (740-814 GBq/dm 3 ). The results led to the development of the kits in which ascorbic or gentisic acid are the standards component in the kit composition (author)

Burn-up determination of irradiated uranium oxide by means of direct gama spectrometry and by radiochemical method

International Nuclear Information System (INIS)

Cunha, I.I.L.; Nastasi, M.J.C.; Lima, F.W.

1981-09-01

The burn-up of thermal neutrons irradiated U 3 O 8 (natural uranium) samples has been determined by using both direct gamma spectrometry and radiochemical methods and the results obtained were compared. The fission products 144 Ce, 103 Ru, 106 Ru, 137 Cs and 95 Zr were chosen as burn-up monitors. In order to isolate the radioisotopes chosen as monitors, a radiochemical separation procedure has been established, in which the solvent extraction technique was used to separate cerium, cesium and ruthenium one from the other and all of them from uranium. The separation between zirconium and niobium and of both elements from the other radioisotopes and uranium was accomplished by means of adsorption on a silica-gel column, followed by selective elution of zirconium and of niobium. When use was made of the direct gamma-ray spectrometry method, the radioactivity of each nuclide of interest was measured in presence of all others. For this purpose use was made of gamma-ray spectrometry and of a Ge-Li detector. Comparison of burn-up values obtained by both methods was made by means of Student's 't' test, and this showed that results obtained in each case are statistically equal. (Author) [pt

Shelf stable intermediate moisture fruit cubes using radiation technology

International Nuclear Information System (INIS)

Mishra, Bibhuti B.; Saxena, Sudhanshu; Gautam, Satyendra; Chander, Ramesh; Sharma, Arun

2009-01-01

A process has been developed to prepare shelf stable ready-to-eat (RTE) intermediate moisture pineapple slices and papaya cubes using radiation technology. The combination of hurdles including osmotic dehydration, blanching, infrared drying, and gamma radiation dose of 1 kGy successfully reduced the microbial load to below detectable limit. The shelf life of the intermediate moisture pineapple slices and papaya cubes was found to be 40 days at ambient temperature (28 ± 2 deg C). The control samples spoiled within 6 days. The RTE intermediate moisture fruit products were found to have good texture, colour and sensory acceptability during this 40 days storage. (author)

Intermediate care: for better or worse? Process evaluation of an intermediate care model between a university hospital and a residential home

NARCIS (Netherlands)

Plochg, Thomas; Delnoij, Diana M. J.; van der Kruk, Tineke F.; Janmaat, Tonnie A. C. M.; Klazinga, Niek S.

2005-01-01

Background: Intermediate care was developed in order to bridge acute, primary and social care, primarily for elderly persons with complex care needs. Such bridging initiatives are intended to reduce hospital stays and improve continuity of care. Although many models assume positive effects, it is

Radiochemical synthesis of a carbon-supported Pt–SnO2 bicomponent nanostructure exhibiting enhanced catalysis of ethanol oxidation

International Nuclear Information System (INIS)

Okazaki, Tomohisa; Seino, Satoshi; Nakagawa, Takashi; Kugai, Junichiro; Ohkubo, Yuji; Akita, Tomoki; Nitani, Hiroaki; Yamamoto, Takao A.

2015-01-01

Carbon-supported Pt–SnO 2 electrocatalysts with various Sn/Pt molar ratios were prepared by an electron beam irradiation method. These catalysts were composed of metallic Pt particles approximately 5 nm in diameter together with low crystalline SnO 2 . The contact between the Pt and SnO 2 in these materials varied with the amount of dissolved oxygen in the precursor solutions and it was determined that intimate contact between the Pt and SnO 2 significantly enhanced the catalytic activity of these materials during the ethanol oxidation reaction. The mechanism by which the contact varies is discussed based on the radiochemical reduction process. - Highlights: • Ethanol oxidation catalysis was enhanced by Sn-addition, far less than ever reported. • Pt–SnO 2 contact is crucial to the catalysis enhancement, alloying of Sn is not necessary. • Nano-scaled intimate contact between Pt and SnO 2 was directly observed

Literature search, review, and compilation of data for chemical and radiochemical sensors: Task 1 report

International Nuclear Information System (INIS)

1993-01-01

During the next several decades, the US Department of Energy is expected to spend tens of billions of dollars in the characterization, cleanup, and monitoring of DOE's current and former installations that have various degrees of soil and groundwater contamination made up of both hazardous and mixed wastes. Each of these phases will require site surveys to determine type and quantity of hazardous and mixed wastes. It is generally recognized that these required survey and monitoring efforts cannot be performed using traditional chemistry methods based on laboratory evaluation of samples from the field. For that reason, a tremendous push during the past decade or so has been made on research and development of sensors. This report contains the results of an extensive literature search on sensors that are used or have applicability in environmental and waste management. While restricting the search to a relatively small part of the total chemistry spectrum, a sizable body of reference material is included. Results are presented in tabular form for general references obtained from data base searches, as narrative reviews of relevant chapters from proceedings, as book reviews, and as reviews of journal articles with particular relevance to the review. Four broad sensor types are covered: electrochemical processes, piezoelectric devices, fiber optics, and radiochemical processes. The topics of surface chemistry processes and biosensors are not treated separately because they often are an adjunct to one of the four sensors listed. About 1,000 tabular entries are listed, including selected journal articles, reviews of conference/meeting proceedings, and books. Literature to about mid-1992 is covered

Literature search, review, and compilation of data for chemical and radiochemical sensors: Task 1 report

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-01-01

During the next several decades, the US Department of Energy is expected to spend tens of billions of dollars in the characterization, cleanup, and monitoring of DOE`s current and former installations that have various degrees of soil and groundwater contamination made up of both hazardous and mixed wastes. Each of these phases will require site surveys to determine type and quantity of hazardous and mixed wastes. It is generally recognized that these required survey and monitoring efforts cannot be performed using traditional chemistry methods based on laboratory evaluation of samples from the field. For that reason, a tremendous push during the past decade or so has been made on research and development of sensors. This report contains the results of an extensive literature search on sensors that are used or have applicability in environmental and waste management. While restricting the search to a relatively small part of the total chemistry spectrum, a sizable body of reference material is included. Results are presented in tabular form for general references obtained from data base searches, as narrative reviews of relevant chapters from proceedings, as book reviews, and as reviews of journal articles with particular relevance to the review. Four broad sensor types are covered: electrochemical processes, piezoelectric devices, fiber optics, and radiochemical processes. The topics of surface chemistry processes and biosensors are not treated separately because they often are an adjunct to one of the four sensors listed. About 1,000 tabular entries are listed, including selected journal articles, reviews of conference/meeting proceedings, and books. Literature to about mid-1992 is covered.

Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

Czech Academy of Sciences Publication Activity Database

Kučera, Jan; Byrne, A. R.; Mizera, Jiří; Lučaníková, M.; Řanda, Zdeněk

2006-01-01

Roč. 269, č. 2 (2006), s. 251-257 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA203/04/0943 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiochemical neutron activation analysis * rhenium * biological and environmental samples Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.509, year: 2006

Negotiating comfort in low energy housing: The politics of intermediation

International Nuclear Information System (INIS)

Grandclément, Catherine; Karvonen, Andrew; Guy, Simon

2015-01-01

Optimising the energy performance of buildings is technically and economically challenging but it also has significant social implications. Maintaining comfortable indoor conditions while reducing energy consumption involves careful design, construction, and management of the built environment and its inhabitants. In this paper, we present findings from the study of a new low energy building for older people in Grenoble, France where conflicts emerged over the simultaneous pursuit of energy efficiency and comfort. The findings contribute to the contemporary literature on the sociotechnical study of buildings and energy use by focusing on intermediation, those activities that associate a technology to end users. Intermediation activities take many forms, and in some cases, can result in the harmonisation or alignment of energy efficiency goals and comfort goals. In other cases, intermediation is unsuccessful, leading to the conventional dichotomy between optimising technical performance and meeting occupant preferences. By highlighting the multiple ways that comfort and energy efficiency is negotiated, we conclude that buildings are provisional achievements that are constantly being intermediated. This suggests that building energy efficiency policies and programmes need to provide opportunities for intermediaries to negotiate the desires and preferences of the multiple stakeholders that are implicated in low energy buildings. -- Highlights: •Energy efficiency and comfort are two possibly contradictory aims of buildings. •We study the pursuit of these aims at the occupation stage of a new building. •Aligning these aims involve negotiating them with occupants. •Intermediation processes are key to such negotiations. •Intermediation processes involve both actors and technical devices

Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

International Nuclear Information System (INIS)

Jaegers, P.J.; Sanchez, R.G.

1996-01-01

Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

Intermediate Collaborative Adaptive Management Strategies Build Stakeholder Capacity

Directory of Open Access Journals (Sweden)

Martha C. Monroe

2013-06-01

Full Text Available Efforts to implement collaborative adaptive management (CAM often suffer from challenges, such as an unwillingness of managers to share power, unresolved conflicts between stakeholders, and lack of capacity among stakeholders. Some aspects considered essential to CAM, e.g., trust and stakeholder capacity, may be more usefully viewed as goals for intermediate strategies rather than a set of initial conditions. From this perspective, intermediate steps that focus on social learning and building experience could overcome commonly cited barriers to CAM. An exploration of Springs Basin Working Groups, organized around major clusters of freshwater springs in north Florida, provides a case study of how these intermediate steps enable participants to become more reasonable and engaged. This strategy may be easily implemented by agencies beginning a CAM process.

Critical Intermediate Structure That Directs the Crystalline Texture and Surface Morphology of Organo-Lead Trihalide Perovskite.

Science.gov (United States)

Chia, Hao-Chung; Sheu, Hwo-Shuenn; Hsiao, Yu-Yun; Li, Shao-Sian; Lan, Yi-Kang; Lin, Chung-Yao; Chang, Je-Wei; Kuo, Yen-Chien; Chen, Chia-Hao; Weng, Shih-Chang; Su, Chun-Jen; Su, An-Chung; Chen, Chun-Wei; Jeng, U-Ser

2017-10-25

We have identified an often observed yet unresolved intermediate structure in a popular processing with dimethylformamide solutions of lead chloride and methylammonium iodide for perovskite solar cells. With subsecond time-resolved grazing-incidence X-ray scattering and X-ray photoemission spectroscopy, supplemental with ab initio calculation, the resolved intermediate structure (CH 3 NH 3 ) 2 PbI 2 Cl 2 ·CH 3 NH 3 I features two-dimensional (2D) perovskite bilayers of zigzagged lead-halide octahedra and sandwiched CH 3 NH 3 I layers. Such intermediate structure reveals a hidden correlation between the intermediate phase and the composition of the processing solution. Most importantly, the 2D perovskite lattice of the intermediate phase is largely crystallographically aligned with the [110] planes of the three-dimensional perovskite cubic phase; consequently, with sublimation of Cl ions from the organo-lead octahedral terminal corners in prolonged annealing, the zigzagged octahedral layers of the intermediate phase can merge with the intercalated methylammonium iodide layers for templated growth of perovskite crystals. Regulated by annealing temperature and the activation energies of the intermediate and perovskite, deduced from analysis of temperature-dependent structural kinetics, the intermediate phase is found to selectively mature first and then melt along the layering direction for epitaxial conversion into perovskite crystals. The unveiled epitaxial conversion under growth kinetics controls might be general for solution-processed and intermediate-templated perovskite formation.

The determination of the radiochemical purity of 99Tcm-DTPA-HSA injection

International Nuclear Information System (INIS)

Yin Guangrong; Zhang Yan

1996-01-01

A simple, rapid analytical method of radiochemical purity for the 99 Tc m -DTPA-HSA injection is established. 99 Tc m (VII), 99 Tc m (IV) and labelled compound 99 Tc m -DTPA-HSA are separated by two systems of paper chromatography on Whatman No.1. The solvent of the system A is 85% methanol and that of the system B is water-95% alcohol-ammonium hydroxide (volume ratio is 5:2:1). 90 Tc m (IV) and labelled compound are located at the origin, while R f of 99 Tc m (VII) is about 0.4-0.5 in the system A. R f of 99 Tc m (VII) and labelled compound are about 0.7-0.8, while 99 Tc m (IV) is located at the origin in the system B

On spallation and fragmentation of heavy ions at intermediate energies

International Nuclear Information System (INIS)

Musulmanbekov, G.; Al-Haidary, A.

2002-01-01

A new code for simulation of spallation and (multi)fragmentation of nuclei in proton and nucleus induced collisions at intermediate and high energies is developed. The code is a combination of modified intranuclear cascade model with traditional fission - evaporation part and multifragmentation part based on lattice representation of nuclear structure and percolation approach. The production of s-wave resonances and formation time concept included into standard intranuclear cascade code provides correct calculation of excitation energy of residues. This modified cascade code served as a bridge between low and high energy model descriptions of nucleus-nucleus collisions. A good agreement with experiments has been obtained for multiparticle production at intermediate and relatively high energies. Nuclear structure of colliding nuclei is represented as face centered cubic lattice. This representation, being isomorphic to the shell model of nuclear structure, allows to apply percolation approach for nuclear fragmentation. The offered percolation model includes both site and bond percolation. Broken sites represent holes left by nucleons knocked out at cascade state. Therefore, in the first cascade stage mutual rescattering of the colliding nuclei results in knocking some nucleons out of them. After this fast stage paltrily destruct and excited residues remain. On the second stage residual nuclei either evaporate nucleons and light nuclei up to alpha-particles or fragment into pieces with intermediate masses. The choice depends on residue's destruction degree. At low excitation energy and small destruction of the residue the evaporation and fission mechanisms are preferable. The more excitation energy and destruction the more probability of (multi)fragmentation process. Moreover, the more destruction degree of the residual the more the site percolation probability. It is concluded, that at low and intermediate excitation energies the fragmentation of nuclei is slow

Technology Summary Advancing Tank Waste Retreival And Processing

International Nuclear Information System (INIS)

Sams, T.L.

2010-01-01

This technology overview provides a high-level summary of technologies being investigated and developed by Washington River Protection Solutions (WRPS) to advance Hanford Site tank waste retrieval and processing. Technology solutions are outlined, along with processes and priorities for selecting and developing them. Hanford's underground waste storage tanks hold approximately 57 million gallons of radiochemical waste from nuclear defense production - more tank waste than any other site in the United States. In addition, the waste is uniquely complicated since it contains constituents from at least six major radiochemical processes and several lesser processes. It is intermixed and complexed more than any other waste collection known to exist in the world. The multi-faceted nature of Hanford's tank waste means that legally binding agreements in the Federal Facility Agreement and Consent Order (known as the Tri-Party Agreement) and between the Department of Energy (DOE) and its contractors may not be met using current vitrification schedules, plans and methods. WRPS and the DOE are therefore developing, testing, and deploying technologies to ensure that they can meet the necessary commitments and complete the DOE's River Protection Project (RPP) mission within environmentally acceptable requirements. Technology solutions are outlined, along with processes and priorities for selecting and developing them.

ESL intermediate/advanced writing

CERN Document Server

Munoz Page, Mary Ellen; Jaskiewicz, Mary

2011-01-01

Master ESL (English as a Second Language) Writing with the study guide designed for non-native speakers of English. Skill-building lessons relevant to today's topics help ESL students write complete sentences, paragraphs, and even multi-paragraph essays. It's perfect for classroom use or self-guided writing preparation.DETAILS- Intermediate drills for improving skills with parallel structure, mood, correct shifting errors & dangling participles- Advanced essay drills focusing on narrative, descriptive, process, reaction, comparison and contrast- Superb preparation for students taking the TOEFL

Radiochemically-Supported Microbial Communities: A Potential Mechanism for Biocolloid Production of Importance to Actinide Transport

Energy Technology Data Exchange (ETDEWEB)

Moser, Duane P. [Desert Research Inst., Nevada University, Reno, NV (United States); Hamilton-Brehm, Scott D. [Desert Research Inst., Nevada University, Reno, NV (United States); Fisher, Jenny C. [Desert Research Inst., Nevada University, Reno, NV (United States); Bruckner, James C. [Desert Research Inst., Nevada University, Reno, NV (United States); Kruger, Brittany [Desert Research Inst., Nevada University, Reno, NV (United States); Sackett, Joshua [Desert Research Inst., Nevada University, Reno, NV (United States); Russell, Charles E. [Desert Research Inst., Nevada University, Reno, NV (United States); Onstott, Tullis C. [Princeton Univ., NJ (United States); Czerwinski, Ken [Univ. of Nevada, Las Vegas, NV (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, James H. [Northwest Missouri State Univ., Maryville, MO (United States)

2014-06-01

Due to the legacy of Cold War nuclear weapons testing, the Nevada National Security Site (NNSS, formerly known as the Nevada Test Site (NTS)) contains millions of Curies of radioactive contamination. Presented here is a summary of the results of the first comprehensive study of subsurface microbial communities of radioactive and nonradioactive aquifers at this site. To achieve the objectives of this project, cooperative actions between the Desert Research Institute (DRI), the Nevada Field Office of the National Nuclear Security Administration (NNSA), the Underground Test Area Activity (UGTA), and contractors such as Navarro-Interra (NI), were required. Ultimately, fluids from 17 boreholes and two water-filled tunnels were sampled (sometimes on multiple occasions and from multiple depths) from the NNSS, the adjacent Nevada Test and Training Range (NTTR), and a reference hole in the Amargosa Valley near Death Valley. The sites sampled ranged from highly-radioactive nuclear device test cavities to uncontaminated perched and regional aquifers. Specific areas sampled included recharge, intermediate, and discharge zones of a 100,000-km2 internally-draining province, known as the Death Valley Regional Flow System (DVRFS), which encompasses the entirety of the NNSS/NTTR and surrounding areas. Specific geological features sampled included: West Pahute and Ranier Mesas (recharge zone), Yucca and Frenchman Flats (transitional zone), and the Western edge of the Amargosa Valley near Death Valley (discharge zone). The original overarching question underlying the proposal supporting this work was stated as: Can radiochemically-produced substrates support indigenous microbial communities and subsequently stimulate biocolloid formation that can affect radionuclides in NNSS subsurface nuclear test/detonation sites? Radioactive and non-radioactive groundwater samples were thus characterized for physical parameters, aqueous geochemistry, and microbial communities using both DNA- and

Utility of reversed phase high performance liquid chromatography for on-line yield determination of radiochemical separations: Studies with cobalt

International Nuclear Information System (INIS)

Subramanian, S.; Woittiez, J.R.W.

1993-01-01

This article indicates the potentials of high performance liquid chromatography (HPLC) as a radiochemical technique for multielement separation of neutron irradiated samples. The focus lies on the convenience to use the detector signal of the eluted components to indicate the chemical yield of the analyte, which has often proved to be a crucial step in radiochemical separations. Two signals have been utilized. The UV signal of the metal-ligand complexes separated by reversed phase HPLC and the radioactive response as a result of sample irradiation of carrier-tracer addition. Change in ratio is discussed between the two signals, if any, for a specific sample. Losses of metal as much as 65% were simulated and corrected using the individual UV response. The method promises improved accuracy for elemental analysis despite losses suffered during the various chemical steps. The procedure omits the necessity of additional analytical steps for yield determination. The present article aims at the chromatographic part of the study. Cobalt as cobalt diethyldithiocarbamate has been used to demonstrate the viability of the concept. The separation was developed on c C18 reverse phase analytical column and optimized on a semi preparative one

CONDITIONING OF INTERMEDIATE-LEVEL WASTE AT FORSCHUNGSZENTRUM JUELICH GMBH

International Nuclear Information System (INIS)

Krumbach, H.

2003-01-01

This contribution to the group of low-level, intermediate, mixed and hazardous waste describes the conditioning of intermediate-level mixed waste (dose rate above 10 mSv/h at the surface) from Research Centre Juelich (FZJ). Conditioning of the waste by supercompaction is performed at Research Centre Karlsruhe (FZK). The waste described is radioactive waste arising from research at Juelich. This waste includes specimens and objects from irradiation experiments in the research reactors Merlin (FRJ-1) and Dido (FRJ-2) at FZJ. In principle, radioactive waste at Forschungszentrum Juelich GmbH is differentiated by the surface dose rate at the waste package. Up to a surface dose rate of 10 mSv/h, the waste is regarded as low-level. The radioactive waste described here has a surface dose rate above 10 mSv/h. Waste up to 10 mSv/h is conditioned at the Juelich site according to different conditioning methods. The intermediate-level waste can only be conditioned by supercompaction in the processing facility for intermediate-level waste from plant operation at Research Centre Karlsruhe. Research Centre Juelich also uses this waste cell to condition its intermediate-level waste from plant operation

Determination of radiochemical yields of 186Re-labelled complexes using thin layer chromatography

International Nuclear Information System (INIS)

Konirova, R.; Kohlickova, M.; Jedinakova-Krizova, V.

1999-01-01

The reaction conditions for synthesis of three rhenium complexes 186 Re-methylendiphosphonate (MDP), 186 Re-hydroxyethylidendiphosphonate (HEDP) and 186 Re-citrate have been investigated. Radiochemical yield of complexation has been determined by thin layer chromatography and paper chromatography. The rhenium complexation with corresponding ligand is dependent on pH values of reaction mixture, concentration of studied ligand (MDP, HEDP and sodium citrate) and concentration of reducing agent. Stannous chloride with ascorbic acid (as antioxidant) was used for reduction of perrhenate. The labeling yield of 186 Re-MDP was about 90 %, of 186 Re-HEDP more than 80 % and more than 75 % for 186 Re-citrate under optimum conditions. Besides, the possibility of application of porphyrins as organic ligands for complexation with rhenium isotopes is examined. (authors)

Radiochemical determination of Inertial Confinement Fusion capsule compression at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Shaughnessy, D. A., E-mail: shaughnessy2@llnl.gov; Moody, K. J.; Gharibyan, N.; Grant, P. M.; Gostic, J. M.; Torretto, P. C.; Wooddy, P. T.; Bandong, B. B.; Cerjan, C. J.; Hagmann, C. A.; Caggiano, J. A.; Yeamans, C. B.; Bernstein, L. A.; Schneider, D. H. G.; Henry, E. A.; Fortner, R. J. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Despotopulos, J. D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Radiochemistry Program, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States)

2014-06-15

We describe a radiochemical measurement of the ratio of isotope concentrations produced in a gold hohlraum surrounding an Inertial Confinement Fusion capsule at the National Ignition Facility (NIF). We relate the ratio of the concentrations of (n,γ) and (n,2n) products in the gold hohlraum matrix to the down-scatter of neutrons in the compressed fuel and, consequently, to the fuel's areal density. The observed ratio of the concentrations of {sup 198m+g}Au and {sup 196g}Au is a performance signature of ablator areal density and the fuel assembly confinement time. We identify the measurement of nuclear cross sections of astrophysical importance as a potential application of the neutrons generated at the NIF.

Development of a radiochemical neutron activation analysis procedure for determination of rhenium in biological and environmental samples at ultratrace level

International Nuclear Information System (INIS)

Kucera, J.; Lucanikova, M.; Czech Technical Univ., Prague

2006-01-01

Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng x g -1 level. Concentrations of Re in the range of 0.1 to 2.4 ng x g -1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of ∼ 10 ng x g -1 was found. Significantly elevated values of Re, up to 90 ng x g -1 were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99 Tc values had previously been determined suggested possible competition between Re and Tc in the accumulation process. (author)

Determination of trace elements in bottled water in Greece by instrumental and radiochemical neutron activation analyses

International Nuclear Information System (INIS)

Soupioni, M.J.; Symeopoulos, B.D.; Papaefthymiou, H.V.

2006-01-01

Four different bottled water brands sold in Greece in the winter of 2001-2002 were analyzed for a wide range of chemical elements, using neutron activation analysis (NAA). The elements Na and Br were determined instrumentally (INAA), whereas the other metals and trace elements radiochemically (RNAA). The results indicated that the mean level of all the elements determined in the samples were well within the European Union (EU) directive on drinking water and accomplish the drinking water standards of the World Health Organisation (WHO) as well as of the Food and Drug Administration (FDA). (author)

The effect of lunar soil, metal oxides on thermal and radio-chemical stability of amino acids

International Nuclear Information System (INIS)

Khenokh, M.A.; Lapinskaya, E.M.

1983-01-01

Data on study of the effect of lunar soil and some metal oxides characteristic both for land and sea basaltS of lunar sojls on thermal and radio-chemical stability of amino acids are presented. The data obtained permit to suppose that extremely small quantity of amino acids discovered in lunar soil is conditioned by their decomposition under combined effect of different types of radiation, solar wind and sharp change of temperature. Probably, the effect of soil on photochemical activity of UV-radiation of the Sun and solid-phase radiolysis is not practically observed

[Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions]. Nuclear chemistry progress report, August 1, 1990--August 1, 1991

Energy Technology Data Exchange (ETDEWEB)

Loveland, W.D.

1991-08-01

The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ``best`` semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.

Early photolysis intermediates of gecko and bovine artificial visual pigments.

Science.gov (United States)

Lewis, J W; Liang, J; Ebrey, T G; Sheves, M; Livnah, N; Kuwata, O; Jäger, S; Kliger, D S

1997-11-25

Nanosecond laser photolysis measurements were conducted on digitonin extracts of artificial pigments prepared from the cone-type visual pigment, P521, of the Tokay gecko (Gekko gekko) retina. Artificial pigments were prepared by regeneration of bleached gecko photoreceptor membranes with 9-cis-retinal, 9-cis-14-methylretinal, or 9-cis-alpha-retinal. Absorbance difference spectra were recorded at a sequence of time delays from 30 ns to 60 microseconds following excitation with a pulse of 477-nm actinic light. Global analysis showed the kinetic data for all three artificial gecko pigments to be best fit by two-exponential processes. These two-exponential decays correspond to similar decays observed after photolysis of P521 itself, with the first process being the decay of the equilibrated P521 BathoP521 BSI mixture to P521 Lumi and the second process being the decay of P521 Lumi to P521 Meta I. In spite of its large blue shift relative to P521, iso-P521 displays a normal chloride depletion induced blue shift. Iso-P521's early intermediates up to Lumi were also blue-shifted, with the P521 BathoP521 BSI equilibrated mixture being 15 nm blue-shifted and P521 Lumi being 8 nm blue-shifted relative to the intermediates formed after P521 photolysis. The blue shift associated with the iso-pigment is reduced or disappears entirely by P521 Meta I. Similar blue shifts were observed for the early intermediates observed after photolysis of bovine isorhodopsin, with the Lumi intermediate blue-shifted 5 nm compared to the Lumi intermediate formed after photolysis of bovine rhodopsin. These shifts indicate that a difference exists between the binding sites of 9- and 11-cis pigments which persists for microseconds at 20 degrees C.

Radiochemical studies on the separation of iodine-131 and radioiodination of some organic compounds

International Nuclear Information System (INIS)

Mohamed, M.A.I.

2010-01-01

its retardation factor (R f ). The second technique is the purification of the labeled compounds by means of high pressure liquid chromatography (HPLC). On the reverse phase RP-18, column eluted with an appropriate solvent where each compound is identified by its retention time (R t ).Chapter III :It deals with the idea of separation of iodine-131 from tellurium targets using the dry distillation method. The factors affecting the production and separation of 131 I were studied such as the oven temperature; the distillation time and the sodium hydroxide concentration, the following flow sheet summarizes the production process. The quality control tests were carried out on the final product (Na 131 I). They were 99.9%, 98.7% for radionuclidic purity and radiochemical purity, respectively and the chemical purity of Te in the final radioiodine was 0.8μg/ml.

Hγ Line Spectrum of Intermediate Polars

Directory of Open Access Journals (Sweden)

Yonggi Kim

1998-06-01

Full Text Available Kim & Beuermann (1995, 1996 have developed a model for the propagation of X-rays from the accreting white dwarf through the infalling material and the re-emission of the energy deposited by photo-absorption in the optical (and UV spectral range. By using this model, we calculate the profiles of the Hγ emission-line spectrum of intermediate polars. Photoabsorption of X-rays by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle, these dependencies allow us to obtain improved insight into the accretion geometry of the intermediate polars. We present results of our calculations and compare them with the Hβ line spectrum (Kim & Beuermann 1996.

Probing specific molecular processes and intermediates by time-resolved Fourier transform infrared spectroscopy: application to the bacteriorhodopsin photocycle.

Science.gov (United States)

Lórenz-Fonfría, Víctor A; Kandori, Hideki; Padrós, Esteve

2011-06-23

We present a general approach for probing the kinetics of specific molecular processes in proteins by time-resolved Fourier transform infrared (IR) spectroscopy. Using bacteriorhodopsin (bR) as a model we demonstrate that by appropriately monitoring some selected IR bands it is possible obtaining the kinetics of the most important events occurring in the photocycle, namely changes in the chromophore and the protein backbone conformation, and changes in the protonation state of the key residues implicated in the proton transfers. Besides confirming widely accepted views of the bR photocycle, our analysis also sheds light into some disputed issues: the degree of retinal torsion in the L intermediate to respect the ground state; the possibility of a proton transfer from Asp85 to Asp212; the relationship between the protonation/deprotonation of Asp85 and the proton release complex; and the timing of the protein backbone dynamics. By providing a direct way to estimate the kinetics of photocycle intermediates the present approach opens new prospects for a robust quantitative kinetic analysis of the bR photocycle, which could also benefit the study of other proteins involved in photosynthesis, in phototaxis, or in respiratory chains.

Metrological aspects of radiochemical methods for determining activity of gamma-emitting nuclides

International Nuclear Information System (INIS)

Shcherbakov, B.Y.

1986-01-01

The author considers the problem of metrological compatibility of the two stages in the radiochemical method of determining the activity of a gamma-emitting nuclide: chemical isolation of the nuclide and radiometric measurement of its activity. The authors show that preparation of the specimen in liquid form provides for important advantages compared with the traditional application of the solid residue onto a flat substate. The work here is of interest for analytical chemists who are involved with determination of the activity of gamma emitting nuclides such as Ru 103, Rh 106, Sn 113, Cs 134, Cs 137, La 140, Ce 141, Ce 144, Hg 203, Na 24, Mn 54, Fe 59, Co 60, Zn 65, Zr 95, and Nb 95, for example, in waste water or in emissions to the atmosphere, with the goal of protecting the environment

The study of radiochemical separation methods on gaseous Fission product krypton-88

International Nuclear Information System (INIS)

Yang Zhihong; Zhang Shengdong; Yang Lei; Ding Youqian; Sun Hongqing; Ma Peng

2012-01-01

Half-life of krypton-88 is 2.84 hours, high fission yields and a relatively large gamma branching ratio is had. The gas is short-lived fission products in burnup measurements. Only New fission products can extract from extraction in gas of fissile irradiation target. But krypton-88 with krypton-85, krypton-87, xenon -135, and xenon-138 is coexisted together, thus radiochemical separation must quickly taken. selected the irradiation time is 1-2 hours and cooling time is best 2 hours for sample preparation, krypton and xenon were separated using activated carbon adsorption, the ratio of krypton and xenon were measured by gamma spectroscopy. Then according to the ratio of krypton-85 and xenon-125 count rate coefficient around separation were calculated yield of krypton and decontamination factor of xenon and the final the yield of krypton-85 is calculated. (authors)

Radiochemical separation of cadmium-109

International Nuclear Information System (INIS)

Egamediev, S.; Mukhtarov, A.; Nurbaeva, D.; Rakhmanov, A.

2006-01-01

Full text: Cadmium-109 has a half-life of 461.9 days and decays by electron capture to 109 Ag with the emission of 88 keV γ-ray (3.79%) along with the characteristic X-ray from the K level of Ag, with energy of 22.5 keV. This radionuclide has found widespread use as a photon source in x-ray fluorescence analysis devices employed in industry for numerous applications such as the direct determination of gold in ores, the analysis of metals and identification of steels. Other applications range from its use as an electron source for measurement of densities of air-pollution samples, to tracer studies in mushrooms and mice and rats. In the nuclear medicine field there is growing interest in employing 109 Cd in a 109 Cd/ 109mA g generator, as an alternative to other biomedical generators of ultra short-lived gamma emitters. There are several methods for the production of 109 Cd in literature: 1. Bombardment of silver cyclotron target via 109 Ag(d,2n) 109 Cd reaction with 16 MeV deuterons. 2. Bombardment of natural silver target via 109 Ag(p,n) 109 Cd reaction with 14 MeV protons. 3. Proton bombardment of natural indium target with 96 MeV protons. 4. Irradiation of enriched 107 Ag target in high-flux nuclear reactor at neutron flux 2x10 15 n·cm -2 ·s -1 via 107 Ag(n,γ) 108 Ag → 108 Cd (n,γ) 109 Cd reaction. 5. Irradiation of enriched 108 Cd target in nuclear reactor at neutron flux 1x10 14 n·cm -2 ·s -1 via 108 Cd (n,γ) 109 Cd reaction. The production of 109 Cd with proton beam via 109 Ag(p,n) 109 Cd reaction is ideal for the cyclotron U-150, since it is not required the change of the regime for the machine functioning. Because of its relatively long half-life the time required for separation is also not an important factor, but its use as an X-ray source requires a very high radiochemical purity. In the present work we studied two methods for separation of 109 Cd from model solution of silver targets. First method is based on precipitation of silver as

Formation of intermediate shocks in both two-fluid and hybrid models

International Nuclear Information System (INIS)

Wu, C.C.; Hada, T.

1991-01-01

Intermediate shocks are shocks with shock frame fluid velocities greater than the Alfven speed ahead and less than the Alfven speed behind, or equivalently, across intermediate shocks the sign of the transverse component of the magnetic field changes. These shocks had been considered extraneous, or nonevolutionary, or unstable, and they had been thought not to correspond to physical reality [Germain, 1960; Jeffrey and Taniuti, 1964; Kantrowitz and Petschek, 1966]. However, it has been shown that intermediate shocks can be formed from continuous waves according to dissipative magnetohydrodynamics (MHD) [Wu, 1987, 1988a, b, 1990]. Thus according to the formation argument which requires that physical shocks be formed by the wave steepening process, the intermediate shocks should be considered physical. Here, intermediate shocks are studied in a two-fluid model that includes finite ion inertia dispersion and in a hybrid model in which the full ion dynamics is retained while the electrons are treated as a massless fluid. The authors show that in both models intermediate shocks can be formed through wave steepening, meaning that they are stable and possess shock structures

Polarization control of multi-photon absorption under intermediate femtosecond laser field

International Nuclear Information System (INIS)

Cheng Wenjing; Liang Guo; Wu Ping; Liu Pei; Jia Tianqing; Sun Zhenrong; Zhang Shian

2017-01-01

It has been shown that the femtosecond laser polarization modulation is a very simple and well-established method to control the multi-photon absorption process by the light–matter interaction. Previous studies mainly focused on the multi-photon absorption control in the weak field. In this paper, we further explore the polarization control behavior of multi-photon absorption process in the intermediate femtosecond laser field. In the weak femtosecond laser field, the second-order perturbation theory can well describe the non-resonant two-photon absorption process. However, the higher order nonlinear effect (e.g., four-photon absorption) can occur in the intermediate femtosecond laser field, and thus it is necessary to establish new theoretical model to describe the multi-photon absorption process, which includes the two-photon and four-photon transitions. Here, we construct a fourth-order perturbation theory to study the polarization control behavior of this multi-photon absorption under the intermediate femtosecond laser field excitation, and our theoretical results show that the two-photon and four-photon excitation pathways can induce a coherent interference, while the coherent interference is constructive or destructive that depends on the femtosecond laser center frequency. Moreover, the two-photon and four-photon transitions have the different polarization control efficiency, and the four-photon absorption can obtain the higher polarization control efficiency. Thus, the polarization control efficiency of the whole excitation process can be increased or decreased by properly designing the femtosecond laser field intensity and laser center frequency. These studies can provide a clear physical picture for understanding and controlling the multi-photon absorption process in the intermediate femtosecond laser field, and also can provide a theoretical guidance for the future experimental realization. (paper)

Comparative TEA for Indirect Liquefaction Pathways to Distillate-Range Fuels via Oxygenated Intermediates

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric; Snowden-Swan, Lesley J.; Talmadge, Michael; Dutta, Abhijit; Jones, Susanne; Ramasamy, Karthikeyan; Gray, Michael; Dagle, Robert; Padmaperuma, Asanga; Gerber, Mark; Sahir, Asad; Tao, Ling; Zhang, Yanan

2017-03-03

This paper presents a comparative techno-economic analysis of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates (derived either via thermochemical or biochemical conversion steps). The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include: biomass-to-syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates, followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. We show that the emerging pathways via oxygenated intermediates have the potential to be cost competitive with the conventional Fischer-Tropsch process. The evaluated pathways and the benchmark process generally exhibit similar fuel yields and carbon conversion efficiencies. The resulting minimum fuel selling prices are comparable to the benchmark at approximately $3.60 per gallon-gasoline equivalent, with potential for two new pathways to be more economically competitive. Additionally, the coproduct values can play an important role in the economics of the processes with oxygenated intermediates derived via syngas fermentation. Major cost drivers for the integrated processes are tied to achievable fuel yields and conversion efficiency of the intermediate steps, i.e., the production of oxygenates/alcohols from syngas and the conversion of oxygenates/alcohols to hydrocarbon fuels.

Elementary computation of radiation doses and shieldings for radiochemical laboratories; Calculo Elemental de dosis y blindajes para laboratorios radioquimicos

Energy Technology Data Exchange (ETDEWEB)

Jimeno de Osso, F

1971-07-01

Simple procedures for the calculation of radiation exposition, half thickness, shield thickness, etc. are described and equations and graphs are included for those gamma-emitting radionuclides, that are more often used in radiochemical laboratories. Application is made of these procedures to three radionuclides, bromine-82, sodium-24 and cobalt-60 which cover a rather wl.de energy range; theoretical results are compared with those obtained from experimental measurements. (Author) 23 refs.

Intermediality and media change

OpenAIRE

2012-01-01

This book is about intermediality as an approach to analysing and understanding media change. Intermediality and Media Change is critical of technological determinism that characterises 'new media discourse' about the ongoing digitalization, framed as a revolution and creating sharp contrasts between old and new media. Intermediality instead emphasises paying attention to continuities between media of all types and privileges a comparative perspective on technological changes in media over ti...

Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

Energy Technology Data Exchange (ETDEWEB)

Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

2011-07-01

The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

Radiochemical and chemical constituents in water from selected wells and springs from the southern boundary of the Idaho National Laboratory to the Hagerman Area, Idaho, 2003

Science.gov (United States)

Rattray, Gordon W.; Wehnke, Amy J.; Hall, L. Flint; Campbell, Linford J.

2005-01-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled water from 14 sites as part of an ongoing study to monitor the water quality of the eastern Snake River Plain aquifer between the southern boundary of the Idaho National Laboratory (INL) and the Burley-Twin Falls-Hagerman area. The State of Idaho, Department of Environmental Quality, Division of INL Oversight and Radiation Control cosampled with the U.S. Geological Survey and the Idaho Department of Water Resources and their analytical results are included in this report. The samples were collected from four domestic wells, two dairy wells, two springs, four irrigation wells, one observation well, and one stock well and analyzed for selected radiochemical and chemical constituents. Two quality-assurance samples, sequential replicates, also were collected and analyzed. None of the concentrations of radiochemical or organic-chemical constituents exceeded the maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. However, the concentration of one inorganic-chemical constituent, nitrate (as nitrogen), in water from site MV-43 was 20 milligrams per liter which exceeded the maximum contaminant level for that constituent. Of the radiochemical and chemical concentrations analyzed for in the replicate-sample pairs, 267 of the 270 pairs (with 95 percent confidence) were statistically equivalent.

Oxidative demethylation of lanosterol in cholesterol biosynthesis: accumulation of sterol intermediates

International Nuclear Information System (INIS)

Shafiee, A.; Trzaskos, J.M.; Paik, Y.K.; Gaylor, J.L.

1986-01-01

With [ 3 H-24,25]-dihydrolanosterol as substrate, large-scale metabolic formation of intermediates of lanosterol demethylation was carried out to identify all compounds in the metabolic process. Utilizing knowledge of electron transport of lanosterol demethylation, we interrupted the demethylation reaction allowing accumulation and confirmation of the structure of the oxygenated intermediates lanost-8-en-3 beta,32-diol and 3 beta-hydroxylanost-8-en-32-al, as well as the demethylation product 4,4-dimethyl-cholesta-8,14-dien-3 beta-ol. Further metabolism of the delta 8.14-diene intermediate to a single product 4,4-dimethyl-cholest-8-en-3 beta-ol occurs under interruption conditions in the presence of 0.5 mM CN-1. With authentic compounds, each intermediate has been rigorously characterized by high performance liquid chromatography and gas-liquid chromatography plus mass spectral analysis of isolated and derivatized sterols. Intermediates that accumulated in greater abundance were further characterized by ultraviolet, 1 H-NMR, and infrared spectroscopy of the isolated sterols

Community dynamics in the siting process for a low to intermediate level nuclear waste facility in Kincardine, Ontario

International Nuclear Information System (INIS)

Al-Haydari, D.

2007-01-01

The use of nuclear technology to generate electricity inevitably produces waste that is detrimental to the environment and human health. Finding communities that will accept nuclear waste disposal facilities is extremely challenging. Furthermore, the siting of a nuclear waste disposal facility is more than a technological analysis, but a matter that includes a variety of social, ethical and political considerations. This study is aimed to assess the role of the place-based community, communities of interest and communities of identity involved in the voluntary siting process for a low to intermediate level nuclear waste disposal facility in Ontario. To accomplish this, a framework was developed and applied though a case study evaluation of the siting process for the Deep Geologic Repository in Kincardine, Ontario. The framework highlights four key procedural principles that were used to analyze the siting process: trust, public participation, equity and risk. The data revealed that the positions of the communities involved in the siting process varied depending on the meaningful fulfillment the four key procedural principles. (author)

Governance-Default Risk Relationship and the Demand for Intermediated and Non-Intermediated Debt

Directory of Open Access Journals (Sweden)

Husam Aldamen

2012-09-01

Full Text Available This paper explores the impact of corporate governance on the demand for intermediated debt (asset finance, bank debt, non-bank private debt and non-intermediated debt (public debt in the Australian debt market. Relative to other countries the Australian debt market is characterised by higher proportions of intermediated or private debt with a lower inherent level of information asymmetry in that private lenders have greater access to financial information (Gray, Koh & Tong 2009. Our firm level, cross-sectional evidence suggests that higher corporate governance impacts demand for debt via the mitigation of default risk. However, this relationship is not uniform across all debt types. Intermediated debt such as bank and asset finance debt are more responsive to changes in governance-default risk relationship than non-bank and non-intermediated debt. The implication is that a firm’s demand for different debt types will reflect its governance-default risk profile.

Characterization of a structural intermediate of flavivirus membrane fusion.

Directory of Open Access Journals (Sweden)

Karin Stiasny

2007-02-01

Full Text Available Viral membrane fusion proceeds through a sequence of steps that are driven by triggered conformational changes of viral envelope glycoproteins, so-called fusion proteins. Although high-resolution structural snapshots of viral fusion proteins in their prefusion and postfusion conformations are available, it has been difficult to define intermediate structures of the fusion pathway because of their transient nature. Flaviviruses possess a class II viral fusion protein (E mediating fusion at acidic pH that is converted from a dimer to a trimer with a hairpin-like structure during the fusion process. Here we show for tick-borne encephalitis virus that exposure of virions to alkaline instead of acidic pH traps the particles in an intermediate conformation in which the E dimers dissociate and interact with target membranes via the fusion peptide without proceeding to the merger of the membranes. Further treatment to low pH, however, leads to fusion, suggesting that these monomers correspond to an as-yet-elusive intermediate required to convert the prefusion dimer into the postfusion trimer. Thus, the use of nonphysiological conditions allows a dissection of the flavivirus fusion process and the identification of two separate steps, in which membrane insertion of multiple copies of E monomers precedes the formation of hairpin-like trimers. This sequence of events provides important new insights for understanding the dynamic process of viral membrane fusion.

Radiochemical search for neutron-rich isotopes of element 107

International Nuclear Information System (INIS)

Schaedel, M.

1987-01-01

Recent mass calculations have indicated that there is a region of deformed nuclei around neutron number N=162 that is especially stable against spontaneous fission. Barrier heights of about 5 MeV for Z = 107 nuclides can be extrapolated. To search for new, neutron-rich isotopes of element 107 in radiochemical experiments with 254 Es as a target an on-line chemical separation of element 107 (EKA-Rhenium), especially from the actinide elements is needed. An on-line gas-phase chemistry was developed with the homolog Re based on the volatility of the oxide which is transported in an O 2 containing atmosphere along a temperature gradient in a quartz tube and is condensed onto a thin Ta coated Ni-foil. The authors applied this technique in two series of experiments with their rotating wheel on-line gas-phase chemistry apparatus at the 88-inch cyclotron where they irradiated 254 Es as a target with 93 MeV and 96 MeV 16 O ions to search for 266 107. The assignment of the observed alpha events between 8 and 9 MeV to possibly (1) non actinide contaminants like 212 Po, (2) known isotopes of heavy elements like 261 105, or (3) a new isotope will be discussed

Virtual Supply Chain Re-Intermediation Through Multi-Agent Systems

National Research Council Canada - National Science Library

Nissen, Mark

2002-01-01

... inflexibility associated with EDI applications. Viewing respective procurement and order fulfillment processes of buyer and seller as an integrated whole along the supply chain, we identify opportunities for virtual supply chain re-intermediation...

Process Design and Economics for the Conversion of Lignocellulosic Biomass to High Octane Gasoline: Thermochemical Research Pathway with Indirect Gasification and Methanol Intermediate

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Talmadge, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dutta, Abhijit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hensley, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schaidle, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Biddy, Mary J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States); Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Jeff [Harris Group, Inc., Seattle, WA (United States); Sexton, Danielle [Harris Group, Inc., Seattle, WA (United States); Yap, Raymond [Harris Group, Inc., Seattle, WA (United States); Lukas, John [Harris Group, Inc., Seattle, WA (United States)

2015-03-01

The U.S. Department of Energy (DOE) promotes research for enabling cost-competitive liquid fuels production from lignocellulosic biomass feedstocks. The research is geared to advance the state of technology (SOT) of biomass feedstock supply and logistics, conversion, and overall system sustainability. As part of their involvement in this program, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) investigate the economics of conversion pathways through the development of conceptual biorefinery process models. This report describes in detail one potential conversion process for the production of high octane gasoline blendstock via indirect liquefaction (IDL). The steps involve the conversion of biomass to syngas via indirect gasification followed by gas cleanup and catalytic syngas conversion to a methanol intermediate; methanol is then further catalytically converted to high octane hydrocarbons. The conversion process model leverages technologies previously advanced by research funded by the Bioenergy Technologies Office (BETO) and demonstrated in 2012 with the production of mixed alcohols from biomass. Biomass-derived syngas cleanup via tar and hydrocarbons reforming was one of the key technology advancements as part of that research. The process described in this report evaluates a new technology area with downstream utilization of clean biomass-syngas for the production of high octane hydrocarbon products through a methanol intermediate, i.e., dehydration of methanol to dimethyl ether (DME) which subsequently undergoes homologation to high octane hydrocarbon products.

Development of Industrial-Scale Fission 99Mo Production Process Using Low Enriched Uranium Target

Directory of Open Access Journals (Sweden)

Seung-Kon Lee

2016-06-01

Full Text Available Molybdenum-99 (99Mo is the most important isotope because its daughter isotope, technetium-99m (99mTc, has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of 99Mo, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of 99Mo technology developments. Most of the industrial-scale 99Mo processes have been based on the fission of 235U. Recently, important issues have been raised for the conversion of fission 99Mo targets from highly enriched uranium to low enriched uranium (LEU. The development of new LEU targets with higher density was requested to compensate for the loss of 99Mo yield, caused by a significant reduction of 235U enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission 99Mo production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the 99Mo production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

Determination Of Rare Earth And Other Elements In YEN-PHU Rare Earth Ore And Other Intermediate Products From The Floatation And Hydrometallurgical Process On Portable XRF Si-PIN Detector

International Nuclear Information System (INIS)

Doan Thanh Son; Phung Vu Phong; Nguyen Hanh Phuc

2014-01-01

The concentration of rare earths elements such as La, Ce, Pr, Nd, Gd and other elements as Ca, Fe, U, Th in Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical process was determined by using Si-PIN detector fluorescence spectrometry. The precision and accuracy of quantitative analysis was tested by standard reference materials and comparative analysis with different analytical methods. The analytical procedures were set-up and applied for the determination of rare earth and other elements in Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical process with high precision and accuracy. (author)

PNGMDR - Characterisation of intermediate-level long-lived wastes

International Nuclear Information System (INIS)

2014-12-01

This document presents the status of the characterization of intermediate-level long-lived wastes which are warehoused on exploited EDF sites or which will be produced during the deconstruction of first-generation reactors. It addresses aspects related to characterisation and packaging of wastes produced before 2015. More specifically, it addresses aspects related to contamination and to activation. Contamination is assessed by measurements whereas activation assessment is based on numerical simulations associated with measurements performed during parcel production. After having mentioned the concerned reactors, the document presents the methodology adopted for these assessments, and reports the progress status of the characterization process for these intermediate-level long-lived wastes

Chemical mode control in nuclear power plant decommissioning during operation of technologies in individual radioactive waste processing plants

International Nuclear Information System (INIS)

Horvath, J.; Dugovic, L.

1999-01-01

Sewage treatment of nuclear power plant decommissioning is performed by system of sewage concentration in evaporator with formation of condensed rest, it means radioactive waste concentrate and breeding steam. During sewage treatment plant operation department of chemical mode performs chemical and radiochemical analysis of sewage set for treatment, chemical and radiochemical analysis of breeding steam condensate which is after final cleaning on ionization filter and fulfilling the limiting conditions released to environment; chemical and radiochemical analysis of heating steam condensate which is also after fulfilling the limiting conditions released to environment. Condensed radioactive concentrate is stored in stainless tanks and later converted into easy transportable and chemically stable matrix from the long term storage point of view in republic storage Mochovce. The article also refer to bituminous plant, vitrification plant, swimming pool decontamination plant of long term storage and operation of waste processing plant Bohunice

Single patient doses of {sup 99m}Tc-HDP: Assessment of radiochemical purity, sterility and extractables from a polypropylene syringe over six hours

Energy Technology Data Exchange (ETDEWEB)

Parkes, S.L.; Varelis, P. [St George Hospital, Kogarah, NSW (Australia). Department of Nuclear Medicine

1997-12-01

Full text: The purpose of this investigation was to determine the radiochemical purity (RCP), sterility and extractables for {sup 99m}Tc oxidronate ({sup 99m}Tc-HDP) stored in polypropylene syringes over < six-hour period. The radiochemical purity was determined using a two-strip ITLC procedure, performed at time 0, 1, 2, 4, 6 hours. The sterility and endotoxin levels were tested by a NATA accredited laboratory, after allowing the radiopharmaceutical to stand at room temperature for six hours in the syringes. Plasticisers and other likely compounds that could be extracted from the syringes into the aqueous solution were determined by high pressure liquid chromatography (HPLC) diode array detection. This analysis involved shaking normal saline in a syringe over night and then injecting an aliquot of this solution onto a C18 analytical column and monitoring the effluent at 200 and 253 nm. The radiochemical purity of {sup 99m}Tc-HDP did not significantly change over the course of the study and remained above the recommended RCP for this radiopharmaceutical. Furthermore, at six hours the RCP of {sup 99m}Tc-HDP stored in both the manufacturer`s vial and a syringe were identical. Sterility testing of {sup 99m}Tc-HDP stored in syringes showed no microbial growth and less than 10 endotoxin units/mL (pass). The HPLC analysis did not show the presence of any extraneous compounds in the aqueous solution. Single patient doses of {sup 99m}Tc-HDP stored in polypropylene syringes over a six-hour period fulfill all the quality control requirements for administration to humans.

Radiochemical determination of the neutron capture cross sections of {sup 241}Am irradiated in the JMTR reactor

Energy Technology Data Exchange (ETDEWEB)

Shinohara, N.; Hatsukawa, Y.; Hata, K.; Kohno, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-03-01

The thermal neutron capture cross section {sigma}{sub 0} and Resonance integral I{sub 0} of {sup 241}Am leading to the production of {sup 242m}Am and {sup 242g}Am were measured by radiochemical method. The cross sections obtained in this study are {sigma}{sub 0}=60.9 {+-} 2.6 barn, I{sub 0}=213 {+-} 13 barn for {sup 241}Am(n,{gamma}){sup 242m}Am and {sigma}{sub 0}=736 {+-} 31 barn, I{sub 0}=1684 {+-} 92 barn for {sup 241}Am(n,{gamma}){sup 242g}Am. (author)

Pollution of agricultural crops with lanthanides, thorium and uranium studied by instrumental and radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Kucera, J.; Mizera, J.; Randa, Z.; Vavrova, M.

2007-01-01

The lanthanide elements, Th and U were measured in soils and agricultural crops collected in an area polluted by emissions from a phosphate fertilizer plant. Concentrations of the above elements in the soil and crop samples were determined by instrumental neutron activation analysis (INAA). Selected crop samples were also analyzed using radiochemical neutron activation analysis (RNAA) based on alkaline-oxidative fusion of the irradiated samples followed by precipitation of REE oxalates. Elevated levels of lanthanides, Th and U were found in some samples, especially in wheat chaff and parsley. (author)

Radiochemical synthesis of 3-(4-[18F] Fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c] pyridin-5-one: A putative dopamine D$4 receptor PET imaging agent

International Nuclear Information System (INIS)

Li, G.C.; Yin, D.Z.; Wang, M.W.; Cheng, D.F.; Wang, Y.X.

2005-01-01

Introduction: The dopamine D 4 receptor has lately received increasing interest since it has been hypothesized to be involved in the pathology and pharmacotherapy of schizophrenia. While this receptor is expressed in lower density in various extrastriatal brain regions and its distribution is still unclear due to the lack of suitable imaging agent and its level change in schizophrenia is controversial. Herein, based on the structure-activity analysis of chromeno[3, 4-c]pyridine- 5-ones as potential dopamine D 4 receptor ligands, a putative D 4 subtype positron emission tomography (PET) radioligand, 3-(4-[ 18 F]fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one ([ 18 F]FHTP), was designed and synthesized. Methods: The radiochemical synthesis route was shown in Figure 1. [ 18 F]Fluoride was produced with a Cyclone-30 (IBA, Belgium) by 18 O(p, n) 18 F reaction using enriched 18 O-H 2 O and eluted from a Dowex 1-X8 anion-exchange column with aqueous potassium carbonate (20 mg/mL). 4-[ 18 F]Fluorobenzaldehyde was prepared according to the method reported by Alan A. Wilson and et al.. Then, 8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one, sodium cyanoborohydride, methanol and acetic acid were added to the dry residue, The mixture was then sealed and heated at 120 degree C for 12 min. At the end of the reaction, the mixture was cooled, diluted with ethyl acetate and washed with water. The extracted organic layer was passed through a small anhydrous magnesium sulfate column. After removal of the solvents in the mixture at 50 degree C under a stream of nitrogen, the obtained residue was redissolved in methanol and purified with a semi-preparative HPLC system, then the desired product was collected. Results: The radiochemical synthesis of [ 18 F]FHTP took around 110 min at EOS with an overall radiochemical yield 19% (decay-corrected) and its radiochemical purity was higher than 95%. Conclusion: A presumed dopamine D 4 receptor PET

Determination of scaling factors to estimate the radionuclide inventory in waste with low and intermediate-level activity from the IEA-R1 reactor

International Nuclear Information System (INIS)

Taddei, Maria Helena Tirollo

2013-01-01

Regulations regarding transfer and final disposal of radioactive waste require that the inventory of radionuclides for each container enclosing such waste must be estimated and declared. The regulatory limits are established as a function of the annual radiation doses that members of the public could be exposed to from the radioactive waste repository, which mainly depend on the activity concentration of radionuclides, given in Bq/g, found in each waste container. Most of the radionuclides that emit gamma-rays can have their activity concentrations determined straightforwardly by measurements carried out externally to the containers. However, radionuclides that emit exclusively alpha or beta particles, as well as gamma-rays or X-rays with low energy and low absolute emission intensity, or whose activity is very low among the radioactive waste, are generically designated as Difficult to Measure Nuclides (DTMs). The activity concentrations of these DTMs are determined by means of complex radiochemical procedures that involve isolating the chemical species being studied from the interference in the waste matrix. Moreover, samples must be collected from each container in order to perform the analyses inherent to the radiochemical procedures, which exposes operators to high levels of radiation and is very costly because of the large number of radioactive waste containers that need to be characterized at a nuclear facility. An alternative methodology to approach this problem consists in obtaining empirical correlations between some radionuclides that can be measured directly – such as 60 Co and 137 Cs, therefore designated as Key Nuclides (KNs) – and the DTMs. This methodology, denominated Scaling Factor, was applied in the scope of the present work in order to obtain Scaling Factors or Correlation Functions for the most important radioactive wastes with low and intermediate-activity level from the IEA-R1 nuclear research reactor. (author)

Conditioning of intermediate-level waste at Forschungszentrum Juelich GmbH

International Nuclear Information System (INIS)

Krumbach, H.

2003-01-01

This contribution to the group of low-level, intermediate, mixed and hazardous waste describes the conditioning of intermediate-level mixed waste (dose rate above 10 mSv/h at the surface) from Research Centre Juelich (FZJ). Conditioning of the waste by supercompaction is performed at Research Centre Karlsruhe (FZK). The waste described is radioactive waste arising from research at Juelich. This waste includes specimens and objects from irradiation experiments in the research reactors Merlin (FRJ-1) and Dido (FRJ-2) at FZJ. In principle, radioactive waste at Forschungszentrum Juelich GmbH is differentiated by the surface dose rate at the waste package. Up to a surface dose rate of 10 mSv/h, the waste is regarded as low-level. The radioactive waste described here has a surface dose rate above 10 mSv/h. Waste up to 10 mSv/h is conditioned at the Juelich site according to different conditioning methods. The intermediate-level waste can only be conditioned by supercompaction in the processing facility for intermediate-level waste from plant operation at Research Centre Karlsruhe. Research Centre Juelich also uses this waste cell to condition its intermediate-level waste from plant operation. (orig.)

MHD intermediate shock discontinuities: Pt. 1

International Nuclear Information System (INIS)

Kennel, C.F.; Blandford, R.D.; Coppi, P.

1989-01-01

Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic. (author)

Structure of a low-population intermediate state in the release of an enzyme product.

Science.gov (United States)

De Simone, Alfonso; Aprile, Francesco A; Dhulesia, Anne; Dobson, Christopher M; Vendruscolo, Michele

2015-01-09

Enzymes can increase the rate of biomolecular reactions by several orders of magnitude. Although the steps of substrate capture and product release are essential in the enzymatic process, complete atomic-level descriptions of these steps are difficult to obtain because of the transient nature of the intermediate conformations, which makes them largely inaccessible to standard structure determination methods. We describe here the determination of the structure of a low-population intermediate in the product release process by human lysozyme through a combination of NMR spectroscopy and molecular dynamics simulations. We validate this structure by rationally designing two mutations, the first engineered to destabilise the intermediate and the second to stabilise it, thus slowing down or speeding up, respectively, product release. These results illustrate how product release by an enzyme can be facilitated by the presence of a metastable intermediate with transient weak interactions between the enzyme and product.

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 industrial-scale fission {sup 99}Mo production process using low enriched uranium target

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Kon; Lee, Jun Sig [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Beyer, Gerd J. [Grunicke Strasse 15, Leipzig (Germany)

2016-06-15

Molybdenum-99 ({sup 99}Mo) is the most important isotope because its daughter isotope, technetium-99m ({sup 99}mTc), has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of {sup 99}Mo, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of {sup 99}Mo technology developments. Most of the industrial-scale {sup 99}Mo processes have been based on the fission of {sup 235}U. Recently, important issues have been raised for the conversion of fission {sup 99}Mo targets from highly enriched uranium to low enriched uranium (LEU). The development of new LEU targets with higher density was requested to compensate for the loss of {sup 99}Mo yield, caused by a significant reduction of {sup 235}U enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission {sup 99}Mo production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the {sup 99}Mo production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

Comparative techno-economic analysis and process design for indirect liquefaction pathways to distillate-range fuels via biomass-derived oxygenated intermediates upgrading: Liquid Transportation Fuel Production via Biomass-derived Oxygenated Intermediates Upgrading

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric C. D. [National Renewable Energy Laboratory, Golden CO USA; Snowden-Swan, Lesley J. [Pacific Northwest National Laboratory, Richland WA USA; Talmadge, Michael [National Renewable Energy Laboratory, Golden CO USA; Dutta, Abhijit [National Renewable Energy Laboratory, Golden CO USA; Jones, Susanne [Pacific Northwest National Laboratory, Richland WA USA; Ramasamy, Karthikeyan K. [Pacific Northwest National Laboratory, Richland WA USA; Gray, Michel [Pacific Northwest National Laboratory, Richland WA USA; Dagle, Robert [Pacific Northwest National Laboratory, Richland WA USA; Padmaperuma, Asanga [Pacific Northwest National Laboratory, Richland WA USA; Gerber, Mark [Pacific Northwest National Laboratory, Richland WA USA; Sahir, Asad H. [National Renewable Energy Laboratory, Golden CO USA; Tao, Ling [National Renewable Energy Laboratory, Golden CO USA; Zhang, Yanan [National Renewable Energy Laboratory, Golden CO USA

2016-09-27

This paper presents a comparative techno-economic analysis (TEA) of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include: biomass to syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. Conversion of biomass-derived syngas to oxygenated intermediates occurs via three different pathways, producing: 1) mixed alcohols over a MoS2 catalyst, 2) mixed oxygenates (a mixture of C2+ oxygenated compounds, predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate) using an Rh-based catalyst, and 3) ethanol from syngas fermentation. This is followed by the conversion of oxygenates/alcohols to fuel-range olefins in two approaches: 1) mixed alcohols/ethanol to 1-butanol rich mixture via Guerbet reaction, followed by alcohol dehydration, oligomerization, and hydrogenation, and 2) mixed oxygenates/ethanol to isobutene rich mixture and followed by oligomerization and hydrogenation. The design features a processing capacity of 2,000 tonnes/day (2,205 short tons) of dry biomass. The minimum fuel selling prices (MFSPs) for the four developing pathways range from $3.40 to $5.04 per gasoline-gallon equivalent (GGE), in 2011 US dollars. Sensitivity studies show that MFSPs can be improved with co-product credits and are comparable to the commercial Fischer-Tropsch benchmark ($3.58/GGE). Overall, this comparative TEA study documents potential economics for the developmental biofuel pathways via mixed oxygenates.

Accelerating the development of an information ecosystem in health care, by stimulating the growth of safe intermediate processing of health information (IPHI

Directory of Open Access Journals (Sweden)

Harshana Liyanage

2013-03-01

Full Text Available Health care, in common with many other industries, is generating large amounts of routine data, data that are challenging to process, analyse or curate, so-called ‘big data’. A challenge for health informatics is to make sense of these data. Part of the answer will come from the development of ontologies that support the use of heterogeneous data sources and the development of intermediate processors of health information (IPHI. IPHI will sit between the generators of health data and information, often the providers of health care, and the managers, commissioners, policy makers, researchers, and the pharmaceutical and other healthcare industries. They will create a health ecosystem by processing data in a way that stimulates improved data quality and potentially health care delivery by providers of health care, and by providing greater insights to legitimate users of data. Exemplars are provided of how a health ecosystem might be encouraged and developed to promote patient safety and more efficient health care. These are in the areas of how to integrate data around the unsafe use of alcohol and to explore vaccine safety. A challenge for IPHI is how to ensure that their processing of data is valid, safe and maintains privacy. Development of the healthcare ecosystem and IPHI should be actively encouraged internationally. Governments, regulators and providers of health care should facilitate access to health data and the use of national and international comparisons to monitor standards. However, most importantly, they should pilot new methods of improving quality and safety through the intermediate processing of health data.

Study of the production of the radiopharmaceutical 18F-FLT in automated system: contribution for process validation

International Nuclear Information System (INIS)

Zanette, Camila

2013-01-01

Radiopharmaceutical 18 F-FLT is a thymidine nucleoside analogue and a promising tumor proliferation marker for PET images. The synthesis of this radiopharmaceutical is not simple, and often has low yields. This radiopharmaceutical has already been studied for some years; however, there is no production, nor are there clinical studies in Brazil. The study of the production process and its compliance with the guidelines of Good Manufacturing Practices (ANVISA) are of extreme importance. This study aimed to investigate the synthesis of this radiopharmaceutical, evaluate methods of quality control that will be used in future production routines, perform cytotoxicity studies, biodistribution studies and PET imaging in animals, thereby contributing to the development and elaboration of the process validation protocol and to the establishment of analytical methods to be used during production routines. Initially, we studied the synthesis and production of 18 F-FLT, with the evaluation of three different temperatures of radiolabeling to check the behavior of the radiochemical yield and stability of the nal product. Studies of analytical methodology comprised the analysis of radionuclide identification, determination of chromatographic profiles, radiochemical purity, residual solvents, and pH. In vitro studies of internalization and cytotoxicity were also carried out. In in vivo studies, we evaluated the pharmacokinetics, biodistribution in healthy animals and in animals with tumor models, in addition to PET/CT images in animals with melanomas. The final product had high radiochemical purity and was stable for up to 10 hours after the synthesis, but got a relatively low radiochemical yield, as described in the literature. The tested analytical methods proved suitable for use in the quality control of 18 F-FLT. In in vitro studies, 18 F-FLT showed a significant percentage of binding to tumor cells, and the nonradiolabeled molecule was not considered toxic for these studied

Use of new composite materials for the determination of Cu, Cd, Mo, As, and Sb in biological samples by radiochemical neutron activation analysis

Czech Academy of Sciences Publication Activity Database

Lučaníková, M.; Kučera, Jan; Šebesta, F.; John, J.

2006-01-01

Roč. 269, č. 2 (2006), s. 463-468 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GA203/04/0943 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiochemical neutron activation analysis * separation using composite materials Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.509, year: 2006

Reactivity of Criegee Intermediates toward Carbon Dioxide.

Science.gov (United States)

Lin, Yen-Hsiu; Takahashi, Kaito; Lin, Jim Jr-Min

2018-01-04

Recent theoretical work by Kumar and Francisco suggested that the high reactivity of Criegee intermediates (CIs) could be utilized for designing efficient carbon capture technologies. Because the anti-CH 3 CHOO + CO 2 reaction has the lowest barrier in their study, we chose to investigate it experimentally. We probed anti-CH 3 CHOO with its strong UV absorption at 365 nm and measured the rate coefficient to be ≤2 × 10 -17 cm 3 molecule -1 s -1 at 298 K, which is consistent with our theoretical value of 2.1 × 10 -17 cm 3  molecule -1 s -1 at the QCISD(T)/CBS//B3LYP/6-311+G(2d,2p) level but inconsistent with their results obtained at the M06-2X/aug-cc-pVTZ level, which tends to underestimate the barrier heights. The experimental result indicates that the reaction of a Criegee intermediate with atmospheric CO 2 (400 ppmv) would be inefficient (k eff < 0.2 s -1 ) and cannot compete with other decay processes of Criegee intermediates like reactions with water vapor (∼10 3 s -1 ) or thermal decomposition (∼10 2 s -1 ).

Monitoring, controlling and safeguarding radiochemical streams at spent fuel reprocessing facilities with optical and gamma-ray spectroscopic methods

International Nuclear Information System (INIS)

Schwantes, J.M.; Bryan, S.A.; Orton, C.R.; Levitskaia, T.G.; Fraga, C.G.

2013-01-01

The International Atomic Energy Agency (IAEA) has established international safeguards standards for fissionable material at spent fuel reprocessing plants to ensure that significant quantities of weapons-usable nuclear material are not diverted from these facilities. For large throughput nuclear facilities, it is difficult to satisfy the IAEA safeguards accountancy goal for detection of abrupt diversion. Currently, methods to verify material control and accountancy (MCA) at these facilities require time-consuming and resource intensive destructive assay (DA). Leveraging new on-line non-destructive assay (NDA) process monitoring techniques in conjunction with the traditional and highly precise DA methods may provide an additional measure to nuclear material accountancy which would potentially result in a more timely, cost-effective and resource efficient means for safeguards verification at such facilities. By monitoring process control measurements (e.g. flowrates, temperatures, or concentrations of reagents, products or wastes), abnormal plant operations can be detected. Pacific Northwest National Laboratory (PNNL) is developing on-line NDA process monitoring technologies based upon gamma-ray and optical spectroscopic measurements to potentially reduce the time and resource burden associated with current techniques. The Multi-Isotope Process (MIP) Monitor uses gamma spectroscopy and multivariate analysis to identify off-normal conditions in process streams. The spectroscopic monitor continuously measures chemical compositions of the process streams including actinide metal ions (U, Pu, Np), selected fission products, and major stable flowsheet reagents using UV-Vis, Near IR and Raman spectroscopy. Multi-variate analysis is also applied to the optical measurements in order to quantify concentrations of analytes of interest within a complex array of radiochemical streams. This paper will provide an overview of these methods and reports on-going efforts to develop

Radiochemical separation and effective dose estimation due to ingestion of 90Sr

International Nuclear Information System (INIS)

Ilic, Z.; Vidic, A.; Deljkic, D.; Sirko, D.; Zovko, E.; Samek, D.

2009-01-01

Since 2007. Institute for Public Health of Federation of Bosnia and Herzegovina-Radiation Protection Centre, within the framework of monitoring of radioactivity of environment carried out measurement of specific activity of 90 Sr content in selected food and water samples. The paper described the methods of measurement and radiochemical separation. Presented results, as average values of specific activity of 90 Sr, were used for estimation of effective dose due to ingestion of 90 Sr for 2007. and 2008. Estimated effective dose for 2007. due to ingestion of 90 Sr for adults was 1,36 μSv and 2,03 μSv for children (10 year old), and for 2008. 0,67 μSv (adults) and 1,01 μSv (children 10 year old). Estimated effective doses for 2007. and 2008. are varied because of different average specific activity radionuclide 90 Sr in selected samples of food, their number, species and origin. (author) [sr

Method Development of Cadmium Investigation in Rice by Radiochemical Neutron Activation Analysis

International Nuclear Information System (INIS)

Promsawad, Arunee; Pareepart, Ratirot; Laoharojanaphand, Sirinart; Arunee, Kongsakpaisal

2007-08-01

Full text: A radiochemical neutron activation analysis for the determination of cadmium was investigated. A chemical separation of cadmium utilized ion exchange chromatography of a strong basic anion-exchange resin BIO-RAD 1X 8 (Chloride form). The adsorbing medium of 2M HCl was found to be the most suitable among the concentration attempted (2, 4, 6, 8 and 10M HCl) and the eluent for desorption of the cadmium from column was 8M NH 3 solution. A chemical yield of 95% was found. The method has been evaluated by analyzing certified reference materials with 0.5.g/g (SRM 1577b, Bovine Liver) and 2.48.g/g (SRM 1566b, Oyster Tissue) cadmium. The agreement of the result with certified values is within 92% for Bovine Liver and 96% for Oyster Tissue. The method developed was applied to determine the cadmium concentrations in contaminated Thai rice. It was found that the cadmium concentrations ranged from 7.4 to 578.9 ppb

Development of the process of energy transfer from a nuclear Power Plant to an intermediate temperature electrolyse; Desarrollo del proceso de transferencia de energia desde una central nuclear a un electrolizador de temperatura intermedia

Energy Technology Data Exchange (ETDEWEB)

Munoz Cervantes, A.; Cuadrado Garcia, P.; Soraino Garcia, J.

2013-07-01

Fifty million tons of hydrogen are consumed annually in the world in various industrial processes. Among them, the ammonia production, oil refining and the production of methanol. One of the methods to produce it is the electrolysis of water, oxygen and hydrogen. This process needs electricity and steam which a central nuclear It can be your source; Hence the importance of developing the transfer process energy between the two. The objective of the study is to characterize the process of thermal energy transfer from a nuclear power plant to an electrolyzer of intermediate temperature (ITSE) already defined. The study is limited to the intermediate engineering process, from the central to the cell.

Radiochemical data obtained by α spectrometry on unrecrystallized fossil coral samples from the Egyptian shoreline of the north-western Red Sea

International Nuclear Information System (INIS)

Choukri, A.; Hakam, O.K.; Reyss, J.L.; Plaziat, J.C.

2007-01-01

In this work, radiochemical results obtained by α spectrometry on 80 unrecrystallized fossil coral samples from the Egyptian shoreline of the north-western Red Sea are presented and discussed. The coral samples were collected in Egypt from the emerged 5e coral reef terraces over 500km from The Ras Gharib-Ras Shukeir depression (28 deg. 10 ' ) in the north to Wadi Lahami (north of Ras Banas, 24 deg. 10 ' ) in the south. The statistical description of radiochemical results (concentrations of U and Th radioisotopes, 234 U/ 238 U activity ratios and ages) obtained on a great number of coral samples showed that it is possible to establish methodological criterions which could be used to validate the measured ages before confronting them to the geological context of sampling sites. The obtained results confirm that the unrecrystallized corals ( 232 Th 238 U varies between 2.2 and 4.9ppm around an average of 3.18+/-0.65ppm. 234 U/ 238 U activity ratios are between 1.08 and 1.28 with an averaged value of 1.164+/-0.016 which exceeds that of present day sea water but which is in agreement with the ratio of 1.16 measured by a precise mass spectrometry in many Pleistocene coral samples. Except three samples dated at least 100ka, the radiochemical age of 5e coral samples vary between 108 and 131ka with an average value of 122.2ka and a standard deviation of 4.3ka. Except for samples from the Zeit area, the reef terrace is between 2 and 6m above the present sea level. This position is similar to the highest sea level from the last interglacial according to the glacio-isostatic rebound calculated for stable regions. This work proves that the large tectonic motions which affected the studied area after the Oligocene ceased after at least the last interglacial period

Dynamic processes in heavy-ion collisions at intermediate energies

Science.gov (United States)

Prendergast, E. P.

1999-03-01

This thesis describes the study of the reaction dynamics in heavy-ion collisions of small nuclear systems at intermediate energies. For this, experiments were performed of 24Mg+27A1 at 45 and 95 AMeV. The experiments described in this thesis were performed at the GANIL accelerator facility in Caeri (France) using the Huygens detectors in conjunction with the ‘MUR’. The Huygens detectors consist of the CsI(Tl)-Wall (CIW) covering the backward hemisphere and, located at mid-rapidity, the central trigger detector (CTD), a gas chamber with microstrip read-out backed by 48 plastic scintillators. The forward region is covered by 16 of the plastic scintillators of the CTD and by the MUR, a time-of-flight wall consisting of 96 plastic scintillator sheets. In earlier experiments only fragments with atomic number, Z, greater then two could be identifled in the CTD. Therefore, an investigation was done into the properties of different drift gases. The use of freon (CF4) in the drift chamber, combined with an increase of the gas pressure to 150 mbar, makes it possible to identify all particles with Z ≥ 2. Under these conditions particles with Z = 1 can only be identifled to approximately 25 AMeV. The Isospin Quantum Molecular Dynamics (IQMD) model has been used, to interpret the measured data. This model gives a microscopical description of heavy-ion collisions and simulates collisions on an event by event basis. In IQMD all protons and neutrons are represented as individual Gaussian wave packets. After initialisation the path of each nucleon is calculated for 200 fm/c, after which the simulation is stopped. At this time, nucleons which are close in space are clustered into fragments. The events generated by IQMD can then be processed by a GEANT detector simulation. This calculation takes into account the effects of the detector on the incoming particles. By using the GEANT simulation it is possible to give a direct comparison between the results of IQMD and the

Thermal theory of autowave processes in low-temperature solid-phase radiochemical reactions

International Nuclear Information System (INIS)

Barelko, V.V.; Barkalov, I.M.; Vaganov, D.A.; Zanin, A.M.; Kiryukhin, D.P.

1982-01-01

A new phenomenon in radiation cryochemistry concerning the class of autowave processes was previously discovered. It was observed in halogenation and hydrohalogenation of hydrocarbons and consisted of spontaneous, laminar propagation of a chemical transformation wave based on a frozen mixture of reagents previously irradiated with 60 Co γ-rays. The effect of the positive inverse correlation between the chemical conversion and brittle fracture of a solid sample of reagents is the phenomenological basis of the phenomenon; formation of fractures triggers a reactive process which takes place on their active surface (or in the layer adjacent to it), and the chemical reaction, in turn, stimulates the subsequent development of the process of decomposition. As a result, a single brittle fracture and chemical conversion wave which moves along the solid sample arises. Different mechanisms of generation of fracture surfaces under the effect of the reaction are possible. A difference in the densities of the initial reagents and the products of the reaction could be one of the causes of brittle fracture, and the thermal stresses induced by the exothermicity of the chemical processes could be another cause. The present work concerns the analysis of the features of the wave process which occurs based on the second, thermal mechanism. The analysis was conducted within the framework of a phenomenological approach which does not require specific definition of the nature of the chemical activation of the system during its brittle fracture

The application of transition metal ion chromatography to the determination of elemental and radiochemical species in PWR primary coolant

International Nuclear Information System (INIS)

Bridle, D.A.; Brown, G.R.; Johnson, P.A.V.

1992-01-01

The accurate determination of both elemental and radiochemical transition metal corrosion products, particularly cobalt and nickel, in PWR coolants is necessary if the transport mechanisms and their role in the development of out-of-core radiation fields are to be fully understood. AEA Technology, Winfrith, has collaborated for several years with a number of PWR utilities in Europe, developing advanced sampling and analytical techniques for the determination of both soluble and insoluble corrosion products in primary coolant. The design and installation of continuously flowing isokinetic capillary modifications to the existing sampling systems has been shown to be an effective method of providing a low, but representative, sample flow from high pressure systems for on-line determination of corrosion product species. Transition metal ion chromatography coupled with gamma-spectrometry has been used to determine both insoluble and soluble elemental and radiochemical species in reactor coolant, with particular attention being given to the determination of soluble elemental cobalt at levels as low as 1 ng per kg. Soluble species were determined directly following their concentration from up to 1 litre of coolant. Insoluble species collected on 0.45 micron filter membranes, following filtration of up to 1500 litres of coolant, were solubilised by fusion with potassium hydrogen sulphate before the application of ion chromatography. In each case the eluant from the chromatographic column was collected and the radionuclides determined by gamma-spectrometry

Development of radiochemical method of analysis of binding of tritium labeled drotaverine hydrochloride with human blood serum albumin

International Nuclear Information System (INIS)

Kim, A.A.; Djuraeva, G.T.; Shukurov, B.V.; Mavlyanov, I.R.

2004-01-01

Full text: The albumin, being a basic functional linkage of numerous endogenous and exogenous substances is the most important protein of blood plasma. At the diseases connected to liver disfunction, collected in blood metabolite reduce connecting ability of albumino. The aim of the present research was a development of radiochemical method of determination of ability of albumin to bind the tritium labeled preparation drotaverine hydrochloride (no - spa). We had developed a micromethod of definition of connecting ability of albumin, allowing to analyse 20 mkl of blood serum. The method consists in incubation of tritium labeled drotaverine hydrochloride with blood serum in vitro, the following fractionation of serum proteins by gel - filtration on a microcolumn with Sephadex G-25, and direct measurement of the radioactivity connected to fraction of proteins of blood serum. The method has been tested on a series of blood serum of control group of healthy people and on a series of blood serum of patients with hepatitis B. We received quantitative characteristics of binding of drotaverine hydrochloride with albumin of patients with hepatitis B. It was preliminary established that binding ability of serum albumin of children with various forms of acute virus hepatitis tends to decrease in comparison with group of the control. Advantage of the developed radiochemical method is high precision and the high sensitivity of detection of infringement of binding ability of albumin. Application of tritium labeled drotaverine hydrochloride allows to measure directly levels of binding of a preparation with albumin

Information acquisition and financial intermediation

OpenAIRE

Boyarchenko, Nina

2012-01-01

This paper considers the problem of information acquisition in an intermediated market, where the specialists have access to superior technology for acquiring information. These informational advantages of specialists relative to households lead to disagreement between the two groups, changing the shape of the intermediation-constrained region of the economy and increasing the frequency of periods when the intermediation constraint binds. Acquiring the additional information is, however, cost...

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)

Radiochemical analyses of surface water from U.S. Geological Survey hydrologic bench-mark stations

Science.gov (United States)

Janzer, V.J.; Saindon, L.G.

1972-01-01

The U.S. Geological Survey's program for collecting and analyzing surface-water samples for radiochemical constituents at hydrologic bench-mark stations is described. Analytical methods used during the study are described briefly and data obtained from 55 of the network stations in the United States during the period from 1967 to 1971 are given in tabular form.Concentration values are reported for dissolved uranium, radium, gross alpha and gross beta radioactivity. Values are also given for suspended gross alpha radioactivity in terms of natural uranium. Suspended gross beta radioactivity is expressed both as the equilibrium mixture of strontium-90/yttrium-90 and as cesium-137.Other physical parameters reported which describe the samples include the concentrations of dissolved and suspended solids, the water temperature and stream discharge at the time of the sample collection.

A Metal Bump Bonding Method Using Ag Nanoparticles as Intermediate Layer

Science.gov (United States)

Fu, Weixin; Nimura, Masatsugu; Kasahara, Takashi; Mimatsu, Hayata; Okada, Akiko; Shoji, Shuichi; Ishizuka, Shugo; Mizuno, Jun

2015-11-01

The future development of low-temperature and low-pressure bonding technology is necessary for fine-pitch bump application. We propose a bump structure using Ag nanoparticles as an intermediate layer coated on a fine-pitch Cu pillar bump. The intermediate layer is prepared using an efficient and cost-saving squeegee-coating method followed by a 100°C baking process. This bump structure can be easily flattened before the bonding process, and the low-temperature sinterability of the nanoparticles is retained. The bonding experiment was successfully performed at 250°C and 39.8 MPa and the bonding strength was comparable to that achieved via other bonding technology utilizing metal particles or porous material as bump materials.

Nicotinamide-NAD sequence: redox process and related behavior, behavior and properties of intermediate and final products

International Nuclear Information System (INIS)

Elving, P.J.; Schmakel, C.O.; Santhanam, K.S.V.

1976-01-01

Illustrations of the application of analytical chemical techniques to the study of chemical phenomena are given. In particular, electrochemical techniques and methodology and, to a lesser extent, spectrophotometry were used to investigate the solution behavior, adsorption, redox processes including coupled chemical reactions, and allied aspects of biologically significant compounds and of their intermediate and final redox products, e.g., the behavior of the free radicals produced by initial one-electron processes. This approach is illustrated by the consideration of the behavior in aqueous and nonaqueous media of a sequence of compounds ranging from nicotinamide (3-carbamoylpyridine) to NAD + and NADP + ; the latter compounds function as coenzymes for the pyridinoproteins which are principal components in the Krebs citric acid cycle and in the electron transport chain in biological redox reactions. The discussion is presented under the following section headings: interpretation of electrochemical behavior; mechanistic patterns; kinetic aspects of charge-transfer and chemical reactions; correlation with theoretically calculated parameters; and, mechanisms of biological oxidation-reduction reactions. The use of pulse radiolysis, chronopotentiometric, and cyclic voltammetric methods in studies on free radical dimerization rates is reviewed in the discussion of the kinetic aspects of charge-transfer and chemical reactions. (188 references)

The Impact of the Principles of Accounting Experience on Student Preparation for Intermediate Accounting

Science.gov (United States)

Carrington, Linda G.

2012-01-01

Both students and instructors alike will generally agree that intermediate accounting courses are among the most difficult and demanding in an accounting or finance curriculum, and perhaps even on the college campus. Intermediate accounting contains subject matter which requires a higher level of thinking and a greater ability to process prior…

Plutonium production story at the Hanford site: processes and facilities history

Energy Technology Data Exchange (ETDEWEB)

Gerber, M.S., Westinghouse Hanford

1996-06-20

This document tells the history of the actual plutonium production process at the Hanford Site. It contains five major sections: Fuel Fabrication Processes, Irradiation of Nuclear Fuel, Spent Fuel Handling, Radiochemical Reprocessing of Irradiated Fuel, and Plutonium Finishing Operations. Within each section the story of the earliest operations is told, along with changes over time until the end of operations. Chemical and physical processes are described, along with the facilities where these processes were carried out. This document is a processes and facilities history. It does not deal with the waste products of plutonium production.

Variational approach to excitation of atomic hydrogen atoms by impacts of protons at intermediate velocities

International Nuclear Information System (INIS)

Lasri, B.; Bouamoud, M.; Gayet, R.

2006-01-01

A variational approach to the excitation of atoms by ion impacts at intermediate velocities is re-examined. Contributions from intermediate states of the target continuum, that were ignored in previous applications of this approach, are taken into account. With this improved variational approach, excitation cross sections of hydrogen atoms by intermediate energy protons are calculated and compared to recent experimental data and to previous theoretical cross sections. The influence of the intermediate target continuum is found to be very weak. In addition, the present approach is shown to apply as long as the capture process is negligible

Standardization of radiochemical techniques aiming the study of Hg volatilization and methylation in water and sediment of gold mining areas in the Amazon region

International Nuclear Information System (INIS)

Guimaraes, Jean Remy Davee

1992-09-01

Methylation of inorganic Hg in aquatic systems is a key process in the environmental cycling of this metal, not yet studied in tropical conditions. Radiochemical techniques were adapted and simplified, aiming at the study of Hg volatilization and methylation in water and sediment of gold mining areas in the Amazon region. Preliminary experiments showed, in 35 days volatilization of up to 32 % of 203 Hg 2+ added to aqueous solutions. Acid K 2 Cr 2 0 7 0.1 M solutions were not effective in 203 Hg 0 trapping and the latter was highly and irreversibly absorbed by a variety of synthetic materials commonly used in laboratory work. Considerably simplified versions of the Furutani and Rudd (1980) radiochemical technique for the determination of methylation rates in environmental samples were developed and showed efficiencies close to 90 % in tests with methyl- 2 0 3 H g standards. In-situ incubations of surface sediments were performed in the Madeira River gold mining region, Rondonia State, Brazil, and potential net Hg methylation rates (MR) of up to 1 %.g-1.h-1 were found in black-water affluent like the Mutum-Parana and Jamari rivers and in the Samuel reservoir. MRs in the Madeira River sediments were lower, ranging 10-5 to 10-3 %.g-1.h-1 . MRs obtained in incubations of samples some weeks after collection were one or two orders of magnitude lower than those resulting from in-situ incubations. Methylation in autoclaved samples was close to minimum detectable rates. MRs in surface water samples was in all cases < 7.10-7 %.ml-1.h-1. The determination of the predominant methylation sites will allow a better standardization of the technique described herein, suitable for MR determinations even under the unfavorable conditions prevailing in the Amazon region. (author)

Discourses and Models of Intermediality

OpenAIRE

Schröter, Jens

2011-01-01

In his article "Discourses and Models of Intermediality" Jens Schröter discusses the question as to what relations do different discourses pose between different "media." Schröter identifies four models of discourse: 1) synthetic intermediality: a "fusion" of different media to super-media, a model with roots in the Wagnerian concept of Gesamtkunstwerk with political connotations, 2) formal (or transmedial) intermediality: a concept based on formal structures not "specific" to one medium but ...

Green methods for the radiochemical separations of no-carrier-added 61Cu, 62Zn from 7Li irradiated cobalt target

International Nuclear Information System (INIS)

Moumita Maiti; Kaustab Ghosh; Susanta Lahiri

2015-01-01

A nat Co target was irradiated with 47 MeV 7 Li beam to produce no-carrier-added 61 Cu, 62 Zn in the target matrix. Two new green radiochemical methods were developed for separation of 61 Cu and 62 Zn from the target matrix, (i) liquid-liquid extraction (LLX) technique using room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim][PF 6 ]) and ammonium pyrrolidinedithiocarbamate (APDC) (ii) adsorption on calcium alginate beads. (author)

Determination of trace amounts of uranium in silicate materials by means of neutron activation analysis involving rapid radiochemical separation

International Nuclear Information System (INIS)

Ebihara, M.; Tomura, Kenji; Masutani, M.

1987-01-01

Uranium is determined in silicate materials such as standard rocks and a meteorite by radiochemical neutron activation analysis. The gamma-ray intensity of 239 U was measured with a planar type pure germanium detector system. The obtained data are mostly consistent with the literature values. Compared with a non-destructive method, the present method was found to improve the sensitivity by at least a factor of ten. Several errors which might be involved in the authors' RNAA procedures were examined and their degrees were evaluated. (author)

Time-resolved resonance Raman spectroscopy of intermediates of bacteriorhodopsin: The bK(590) intermediate.

Science.gov (United States)

Terner, J; Hsieh, C L; Burns, A R; El-Sayed, M A

1979-07-01

We have combined microbeam and flow techniques with computer subtraction methods to obtain the resonance Raman spectrum of the short lived batho-intermediate (bK(590)) of bacteriorhodopsin. Comparison of the spectra obtained in (1)H(2)O and (2)H(2)O, as well as the fact that the bK(590) intermediate shows large optical red shifts, suggests that the Schiff base linkage of this intermediate is protonated. The fingerprint region of the spectrum of bK(590), sensitive to the isomeric configuration of the retinal chromophore, does not resemble the corresponding region of the parent bR(570) form. The resonance Raman spectrum of bK(590) as well as the spectra of all of the other main intermediates in the photoreaction cycle of bacteriorhodopsin are discussed and compared with resonance Raman spectra of published model compounds.

Role of Intermediate Filaments in Vesicular Traffic

Directory of Open Access Journals (Sweden)

Azzurra Margiotta

2016-04-01

Full Text Available Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

Methods for providing intermediates in the synthesis of atorvastatin.

NARCIS (Netherlands)

Dömling, Alexander Stephan Siegfried

2016-01-01

The invention relates to the field of medicinal chemistry, In particular, it relates to methods for providing intermediates in the synthesis of Atorvastatin, a competitive inhibitor of HMG-Co A reductase. Provided is a process for providing a compound having a Formula (I) or a pharmaceutically

Role of compound nuclei in intermediate-energy heavy-ion reactions

International Nuclear Information System (INIS)

Moretto, L.G.; Wozniak, G.J.

1988-05-01

Hot compound nuclei are frequently produced in intermediate-energy reactions through a variety of processes. Their decay is shown to be an important and at times dominant source of complex fragments, high energy-gamma rays, and even pions

Radiostrontium accumulation in animal bones: development of a radiochemical method by ultra low-level liquid scintillation counting for its quantification.

Science.gov (United States)

Iammarino, Marco; Dell'Oro, Daniela; Bortone, Nicola; Mangiacotti, Michele; Chiaravalle, Antonio Eugenio

2018-03-31

Strontium-90 (90Sr) is a fission product, resulting from the use of uranium and plutonium in nuclear reactors and weapons. Consequently, it may be found in the environment as a consequence of nuclear fallouts, nuclear weapon testing, and not correct waste management. When present in the environment, strontium-90 may be taken into animal body by drinking water, eating food, or breathing air. The primary health effects are bone tumors and tumors of the blood-cell forming organs, due to beta particles emitted by both 90Sr and yttrium-90 (90Y). Moreover, another health concern is represented by inhibition of calcification and bone deformities in animals. Actually, radiometric methods for the determination of 90Sr in animal bones are lacking. This article describers a radiochemical method for the determination of 90Sr in animal bones, by ultra low-level liquid scintillation counting. The method precision and trueness have been demonstrated through validation tests (CV% = 12.4%; mean recovery = 98.4%). Detection limit and decision threshold corresponding to 8 and 3 mBecquerel (Bq) kg-1, respectively, represent another strong point of this analytical procedure. This new radiochemical method permits the selective extraction of 90Sr, without interferences, and it is suitable for radiocontamination surveillance programs, and it is also an improvement with respect to food safety controls.

Joint enterprise and the role of the intermediator

DEFF Research Database (Denmark)

Bjørn, Pernille; Simonsen, Jesper

2005-01-01

, by analyzing the failure of inte-grating groupware into two global virtual teams within industry. We present an empirically driven interpretive case study conducted in a large distributed global or-ganization. Based on the empirical observations, we reveal two organizational factors challenging the inte......-gration process: The importance of joint enterprise and the role of the intermediator....

AERE contracts with DoE on the treatment and disposal of intermediate level wastes

International Nuclear Information System (INIS)

Partridge, B.A.

1984-06-01

This document reports work carried out in 1983/84 under 10 contracts between DoE and AERE on the treatment and disposal of intermediate level wastes. Individual summaries are provided for each contract report within the document, under the headings: comparative evaluation of α and βγ irradiated medium level waste forms; modelling and characterisation of intermediate level waste forms based on polymers; optimisation of processing parameters for polymer and bitumen modified cements; ceramic waste forms; radionuclide release during leaching; ion exchange processes; electrical processes for the treatment of medium active liquid wastes; fast reactor fuel element cladding; dissolver residues; flowsheeting/systems study. (U.K.)

Effect of an Intermediate Heat-treatment on a Change of the Corrosion Resistance and Hardness of a HANA-4 Outer Strip

International Nuclear Information System (INIS)

Lee, Myung Ho; Jung, Yang Il; Park, Sang Yoon; Choi, Byoung Kwon; Park, Jeong Yong; Jeong, Yong Hwan; Eom, Kyong Bo; Park, Nam Gyu; Lim, Yoon Soo

2008-01-01

KAERI (Korea Atomic Energy Research Institute) in collaboration with KNF (Korea Nuclear Fuel) undertook some researches on the applicability of HANA-4 and HANA-6 alloys for the spacer grid for a PWR (Pressurized Water Reactor) nuclear fuel. As a part of the research, KAERI studied the effect of the final heat-treatment on the mechanical and corrosion properties of a HANA-4 inner strip. The strip was manufactured with a sheet which had been intermediately heat-treated at about 580 .deg. C for 2.5-4 hours after each cold rolling before being processed into the final strip product. It was mentioned that the process with the intermediate heat treatment needed reviewing to establish an improved manufacturing process for the cold rolling. So, this work tried to check the effect of an intermediate heat-treatment on the properties of a HANA-4 strip using a specimen that was taken from a second hot rolled material before a cold-rolling. The manufacturing processes, with three different kinds of annealings, were introduced to investigate the applicable intermediate heat-treatment process. After all the cold-rolling processes, the Vickers hardness was measured for the final annealed specimens and 60 days of corrosion tests were carried out to check on the effect of the intermediate heat-treatment. Finally, an appropriate intermediate heat-treatment was proposed to improve the manufacturability of the HANA-4 strip

Visual dictionaries as intermediate features in the human brain

Directory of Open Access Journals (Sweden)

Kandan eRamakrishnan

2015-01-01

Full Text Available The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2 and V3. However BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

Determination of isotopic ratios of osmium and ruthenium in meteorites by pretreatment and radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Chinfang Chai; Yongzhong Liu; Xueying Mao

1996-01-01

The isotopic abundance ratios of 190 Os/ 184 Os and 96 Ru/ 102 Ru for the metal phases of the Jilin and Taonan stone meteorites were determined by pretreatment and radiochemical neutron activation analysis. All experimental factors affecting Os and Ru isotopic ratios were discussed, including sampling, standard, irradiation, separation and counting. The statistical errors of measurements for the 199 Os/ 184 Os ratio can be controlled within 1%. The experimental results indicate that the statistically significant anomalies of the 190 Os/ 184 Os and 96 Ru/ 102 Ru ratios have not been found relative to the terrestrial Os and Ru standards. (author). 6 refs., 1 fig., 5 tabs

Groundwater quality in wells in central rural Finland: a microbiological and radiochemical survey

International Nuclear Information System (INIS)

Korhonen, L.; Niskanen, M.; Heinonen-Tanski, H.; Martikainen, P.J.; Salonen, L.; Taipalinen, I.

1996-01-01

The microbiological, physicochemical, and radiochemical water quality from samples of 150 rural wells in Finland was analyzed. Organic matter exceeded 12 mg KMnO4 L(-1) in 63% and nitrate 25 mg NO3 L(-1) in 29% of the wells. NO3--concentrations were higher in wells with cattle. Fecal coliforms and fecal streptococci were found in 10-40%. There was no direct positive correlation between heterotrophic and indicator bacteria. Salmonella or Campylobacter were not detected. Human pathogen Listeria monocytogenes was isolated from two and Yersinia enterocolitica serotypes O5 or O6 from four waters not containing fecal coliforms. Thus, the predictive value of fecal coliforms to indicate these pathogens is poor. Coliphages were found in seven wells. Mean concentrations of radon and long-lived alpha-active radionuclides were lower and those of beta-emitting radionuclides higher than the mean concentrations measured from groundwater in Finland. Radionuclides from the Chernobyl fallout were not detected

Electron-atom scattering at intermediate energies

International Nuclear Information System (INIS)

Kingston, A.E.; Walters, H.R.J.

1982-01-01

The problems of intermediate energy scattering are approached from the low and high energy ends. At low intermediate energies difficulties associated with the use of pseudostates and correlation terms are discussed, special consideration being given to nonphysical pseudoresonances. Perturbation methods appropriate to high intermediate energies are described and attempts to extend these high energy approximations down to low intermediate energies are studied. It is shown how the importance of electron exchange effects develops with decreasing energy. The problem of assessing the 'effective completeness' of pseudostate sets at intermediate energies is mentioned and an instructive analysis of a 2p pseudostate approximation to elastic e - -H scattering is given. It is suggested that at low energies the Pauli Exclusion Principle can act to hide short range defects in pseudostate approximations. (author)

A Functional Examination of Intermediate Cognitive Processes.

Science.gov (United States)

1986-01-01

in terms of levels of processing models (e.g., Craik and Lockhart , 1972; Craik and Tulving, 1975). A similarly counter-intuitive result from a novel...NJ.: Erlbaum. Craik ,F.I.M. & Lockhart ,R.S. (1972). Levels of processing : A framework for memory research. Journal of Verbal Learning and Verbal... processes or at least, a recognition of the correspondence betveen these symbols and external events. ( Craik , 1943, p. 50) Craik thus provides a

Electron emission in collisions of intermediate energy ions with atoms

International Nuclear Information System (INIS)

Garibotti, C.R.

1988-01-01

The aim of this work, is the analysis of the processes of electronic emission produced in the collisions of small ions (H + , He ++ ) of intermediate energy (50 a 200 KeV/amu) with light gaseous targets. (A.C.A.G.) [pt

The intermediate state in Patd

African Journals Online (AJOL)

) Jesus had assumed. (concerning the 'intermediate state') as existing, anything which does not exist. Three basic things about the intermediate state emerge from the parable: (a) Jesus recognizes that at the moment of death, in ipso articulo.

Higher order antibunching in intermediate states

International Nuclear Information System (INIS)

Verma, Amit; Sharma, Navneet K.; Pathak, Anirban

2008-01-01

Since the introduction of binomial state as an intermediate state, different intermediate states have been proposed. Different nonclassical effects have also been reported in these intermediate states. But till now higher order antibunching is predicted in only one type of intermediate state, which is known as shadowed negative binomial state. Recently we have shown that the higher order antibunching is not a rare phenomenon [P. Gupta, P. Pandey, A. Pathak, J. Phys. B 39 (2006) 1137]. To establish our earlier claim further, here we have shown that the higher order antibunching can be seen in different intermediate states, such as binomial state, reciprocal binomial state, hypergeometric state, generalized binomial state, negative binomial state and photon added coherent state. We have studied the possibility of observing the higher order subpoissonian photon statistics in different limits of intermediate states. The effects of different control parameters on the depth of non classicality have also been studied in this connection and it has been shown that the depth of nonclassicality can be tuned by controlling various physical parameters

Make or mix to order: Determining the type of intermediate products in a flour mill

DEFF Research Database (Denmark)

Akkerman, Renzo; van der Meer, Dirk; van Donk, Dirk Pieter

2008-01-01

In contrast to discrete manufacturers, food-processing companies can sometimes produce the same end products in different ways: either mix early and process or process first and mix later. Moreover, a product can be mixed from different raw materials or intermediates. That implies that choices can...... be made not only with regard to where to store, but also what to store, which is currently not covered in Decoupling Point (DP) theory. This paper explores this joint problem for a flour mill. The number and type of intermediate products in the DP is determined using a two-stage mathematical program...

Hydrothermal processes in the Edmond deposits, slow- to intermediate-spreading Central Indian Ridge

Science.gov (United States)

Cao, Hong; Sun, Zhilei; Zhai, Shikui; Cao, Zhimin; Jiang, Xuejun; Huang, Wei; Wang, Libo; Zhang, Xilin; He, Yongjun

2018-04-01

The Edmond hydrothermal field, located on the Central Indian Ridge (CIR), has a distinct mineralization history owing to its unique magmatic, tectonic, and alteration processes. Here, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this area. Based on the mineralogical investigations, the Edmond hydrothermal deposits comprise of high-temperature Fe-rich massive sulfides, medium-temperature Zn-rich sulfide chimney and low-temperature Ca-rich sulfate mineral assemblages. According to these compositions, three distinctive mineralization stages have been identified: (1) low-temperature consisting largely of anhydrite and pyrite/marcasite; (2) medium-high temperature distinguished by the mineral assemblage of pyrite, sphalerite and chalcopyrite; and (3) low-temperature stage characterized by the mineral assemblage of colloidal pyrite/marcasite, barite, quartz, anglesite. Several lines of evidence suggest that the sulfides were influenced by pervasive low-temperature diffuse flows in this area. The hydrothermal deposits are relatively enriched in Fe (5.99-18.93 wt%), Zn (2.10-10.00 wt%) and Ca (0.02-19.15 wt%), but display low Cu (0.28-0.81 wt%). The mineralogical varieties and low metal content of sulfides in the Edmond hydrothermal field both indicate that extensive water circulation is prevalent below the Edmond hydrothermal field. With regard to trace elements, the contents of Pb, Ba, Sr, As, Au, Ag, and Cd are significantly higher than those in other sediment-starved mid-ocean ridges, which is indicative of contribution from felsic rock sources. Furthermore, the multiphase hydrothermal activity and the pervasive water circulation underneath are speculated to play important roles in element remobilization and enrichment. Our findings deepen our understanding about the complex mineralization process in slow- to intermediate-spreading ridges globally.

Radiochemical analysis of concrete samples for decommission of nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Zapata-Garcia, Daniel; Wershofen, Herbert [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100 38116, Braunschweig (Germany); Larijani, Cyrus; Sobrino-Petrirena, Maitane; Garcia-Miranda, Maria; Jerome, Simon M. [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom)

2014-07-01

Decommissioning of the oldest nuclear power reactors are some of the most challenging technological legacy issues many countries will face in forthcoming years, as many power reactors reach the end of their design lives. Decommissioning of nuclear reactors generates large amounts of waste that need to be classified according to their radioactive content. Approximately 10 % of the contaminated material ends up in different repositories (depending on their level of contamination) while the rest is decontaminated, measured and released into the environment or sent for recycling. Such classification needs to be done accurately in order to ensure that both the personnel involved in decommissioning and the population at large are not needlessly exposed to radiation or radioactive material and to minimise the environmental impact of such work. However, too conservative classification strategies should not be applied, in order to make proper use of radioactive waste repositories since space is limited and the full process must be cost-effective. Implicit in decommissioning and classification of waste is the need to analyse large amounts of material which usually combine a complex matrix with a non-homogeneous distribution of the radionuclides. Because the costs involved are large, it is possible to make great savings by the adoption of best available practices, such as the use of validated methods for on-site measurements and simultaneous determination of more than one radionuclide whenever possible. The work we present deals with the development and the validation of a procedure for the simultaneous determination of {sup 241}Am, plutonium isotopes, uranium isotopes and {sup 90}Sr in concrete samples. Samples are firstly ground and fused with LiBO{sub 2} and Li{sub 2}B{sub 4}O{sub 7}. After dissolution of the fused sample, silicate and alkaline elements are removed followed by radiochemical separation of the target radionuclides using extraction chromatography. Measurement

Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (PHB) from a Process Relevant Lignocellulosic Derived Sugar (Poster)

Energy Technology Data Exchange (ETDEWEB)

Wang, W.; Mittal, A.; Mohagheghi, A.; Johnson, D. K.

2014-04-01

PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. Cupriavidus necator is the microorganism that has been most extensively studied and used for PHB production on an industrial scale; However the substrates used for producing PHB are mainly fructose, glucose, sucrose, fatty acids, glycerol, etc., which are expensive. In this study, we demonstrate production of PHB from a process relevant lignocellulosic derived sugar stream, i.e., saccharified slurry from pretreated corn stover. The strain was first investigated in shake flasks for its ability to utilize glucose, xylose and acetate. In addition, the strain was also grown on pretreated lignocellulose hydrolyzate slurry and evaluated in terms of cell growth, sugar utilization, PHB accumulation, etc. The mechanism of inhibition in the toxic hydrolysate generated by the pretreatment and saccharification process of biomass, was also studied.

[Therapy of intermediate uveitis].

Science.gov (United States)

Doycheva, D; Deuter, C; Zierhut, M

2014-12-01

Intermediate uveitis is a form of intraocular inflammation in which the vitreous body is the major site of inflammation. Intermediate uveitis is primarily treated medicinally and systemic corticosteroids are the mainstay of therapy. When recurrence of uveitis or side effects occur during corticosteroid therapy an immunosuppressive treatment is required. Cyclosporine A is the only immunosuppressive agent that is approved for therapy of uveitis in Germany; however, other immunosuppressive drugs have also been shown to be effective and well-tolerated in patients with intermediate uveitis. In severe therapy-refractory cases when conventional immunosuppressive therapy has failed, biologics can be used. In patients with unilateral uveitis or when the systemic therapy is contraindicated because of side effects, an intravitreal steroid treatment can be carried out. In certain cases a vitrectomy may be used.

Hydrogen-antihydrogen oscillations: Signature of intermediate mass scales in GUTs

Directory of Open Access Journals (Sweden)

Uptal Sarkar

1983-01-01

Full Text Available Hydrogen-antihydrogen oscillations and the double nucleon decay (pp, np and nn into two antileptons are discussed in the context of SO(10, E(6 and SU(16 GUTs. It is shown that the intermediate mass scales of the GUTs concerned govern the amplitude of these processes which are found to compete with the other baryon nonconserving processes in SU(16 GUT.

Devising of the method for the determination of small and very small amounts of cadmium in biological materials by radiochemical version of neutron activation analysis

International Nuclear Information System (INIS)

Dybczynski, R.; Samczynski, Z.

1996-01-01

The newly modified version of the method for the determination of cadmium in biological materials by radiochemical NAA based on selective post irradiation separation of Cd using ion exchange rasin Retardion 11A8 is presented. The conditions necessary for the selective retaining of Cd on the column exploiting both anionic and cationic ion exchange function of the resin have been discussed. Depending on the composition of the external solution, cadmium existing in the form of either anionic chloride complexes or cationic amine species is taken up by quaternary ammonium or carboxylate functional groups, respectively while accompanying elements are eluted. The elaborated method was further verified by determine Cd content in several certified biological reference materials using neutron activation analysis. The ion exchange separation procedure assures very high radiochemical purity of the cadmium fraction. Decontamination factors obtained for Mo, Sb, Na, Zn, Co, Sc amounted to 10 3 - 10 6 . Detection limit for Cd was 0.5 μg kg -1 . Analytical results show good agreement with the certified values. (author). 10 refs, 7 figs, 1 tab

Application of radiochemical method under radioecological situation study in locations of radioactive wastes damping in shallow gulfs of the Novaya Zemlya Archipelago

International Nuclear Information System (INIS)

Stepanets, O.V.; Borisov, A.P.; Komarevskij, V.M.; Ligachev, A.N.; Solov'eva

2005-01-01

Results of works carried out on the 'Boris Petrov Academician' research ship on burial locations examination of submarine potential hazardous objects in the Kara Sea and in the Stepovoj, Abrosimov and Stivol'ka gulfs are cited. Comprehensive radioecological studies in the damping locations of solid radioactive wastes in the Novaya Zemlya Archipelago conducted in 2002-2004 with application of radio-chemical methods for certain radionuclides determination in the samples of bottom sediments and water in the immediate vicinity from the submerged objects are allowing to revealing the objective picture of man-caused contamination of water environment near submerged objects and by the gulfs water area. The studies uniting instrumental tools of acoustic search and visual objects inspection, opportunity of sampling of bottom sediments and near bottom water in the object vicinity and away from it with subsequent analysis of selected samples by the method of direct gamma-spectroscopy and radio-chemical concentration of certain radionuclides are permitting to obtain the statistically assisted data set on special concentrations of cesium, strontium, cobalt, plutonium radionuclides in a water layer and bottom sediments. Obtained results with taking into account of hydrological conditions allow to explain the peculiarities of radioactivity distribution in separate water areas

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 1997

Energy Technology Data Exchange (ETDEWEB)

R. C. Bartholomay (USGS); L. M. Williams (USGS); L. J. Campbell (Idaho Department of Water Resources)

1998-12-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled 18 sites as part of the fourth round of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radiochemical and chemical constituents. The samples were collected from seven domestic wells, six irrigation wells, two springs, one dairy well, one observation well, and one stock well. Two quality-assurance samples also were collected and analyzed. None of the radiochemical or chemical constituents exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide- and inorganic-constituent concentrations were greater than their respective reporting levels.

Disruption of TLR3 signaling due to cleavage of TRIF by the hepatitis A virus protease-polymerase processing intermediate, 3CD.

Directory of Open Access Journals (Sweden)

Lin Qu

2011-09-01

Full Text Available Toll-like receptor 3 (TLR3 and cytosolic RIG-I-like helicases (RIG-I and MDA5 sense viral RNAs and activate innate immune signaling pathways that induce expression of interferon (IFN through specific adaptor proteins, TIR domain-containing adaptor inducing interferon-β (TRIF, and mitochondrial antiviral signaling protein (MAVS, respectively. Previously, we demonstrated that hepatitis A virus (HAV, a unique hepatotropic human picornavirus, disrupts RIG-I/MDA5 signaling by targeting MAVS for cleavage by 3ABC, a precursor of the sole HAV protease, 3C(pro, that is derived by auto-processing of the P3 (3ABCD segment of the viral polyprotein. Here, we show that HAV also disrupts TLR3 signaling, inhibiting poly(I:C-stimulated dimerization of IFN regulatory factor 3 (IRF-3, IRF-3 translocation to the nucleus, and IFN-β promoter activation, by targeting TRIF for degradation by a distinct 3ABCD processing intermediate, the 3CD protease-polymerase precursor. TRIF is proteolytically cleaved by 3CD, but not by the mature 3C(pro protease or the 3ABC precursor that degrades MAVS. 3CD-mediated degradation of TRIF depends on both the cysteine protease activity of 3C(pro and downstream 3D(pol sequence, but not 3D(pol polymerase activity. Cleavage occurs at two non-canonical 3C(pro recognition sequences in TRIF, and involves a hierarchical process in which primary cleavage at Gln-554 is a prerequisite for scission at Gln-190. The results of mutational studies indicate that 3D(pol sequence modulates the substrate specificity of the upstream 3C(pro protease when fused to it in cis in 3CD, allowing 3CD to target cleavage sites not normally recognized by 3C(pro. HAV thus disrupts both RIG-I/MDA5 and TLR3 signaling pathways through cleavage of essential adaptor proteins by two distinct protease precursors derived from the common 3ABCD polyprotein processing intermediate.

Chloride effect on the early photolysis intermediates of a gecko cone-type visual pigment.

Science.gov (United States)

Lewis, J W; Liang, J; Ebrey, T G; Sheves, M; Kliger, D S

1995-05-02

Nanosecond laser photolysis measurements were conducted on the cone-type visual pigment P521 in digitonin extracts of Tokay gecko (Gekko gekko) retina containing physiological chloride ion levels and also on samples which had been chloride depleted or which contained high levels (4 M) of chloride. Absorbance difference spectra were recorded at a sequence of time delays from 30 ns to 60 microseconds following excitation with a pulse of either 532- or 477-nm actinic light. Global analysis showed the kinetic decay data for gecko pigment P521 to be best fit by two exponential processes under all chloride conditions. The initial photoproduct detected had a broad spectrum characteristic of an equilibrated mixture of a Batho P521 intermediate with its blue-shifted intermediate (BSI P521) decay product. The first exponential process was assigned to the decay of this mixture to the Lumi P521 intermediate. The second exponential process was identified as the decay of Lumi P521 to Meta I P521. The initial photoproduct's spectrum exhibited a strong dependence on chloride concentration, indicating that chloride affects the composition of the equilibrated mixture of Batho P521 and BSI P521. These results suggest that the affinity for chloride is reduced approximately 5-fold in the Batho P521 intermediate and approximately 50-fold in the BSI P521 intermediate. Chloride concentration also affects the apparent decay rate of the equilibrated mixture. When the apparent decay rate is corrected for the composition of the equilibrated mixture, a relatively invariant microscopic rate constant is obtained for BSI decay (k = 1/55 ns-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Radiochemical applications of insoluble sulfate columns. Analytical possibilities in the field of the fission product solutions

International Nuclear Information System (INIS)

Barrachina, M.; Sauvagnac, R.

1962-01-01

In this paper we go on with our study of the heterogeneous ion-isotopic exchange in column. At present, we apply it to determine the radiochemical composition of the raw solutions used in the industrial recuperation of the long-lived fission products. The separation of the radioelements contained in these solutions is carried out mainly by making use of small columns, 1-3 cm height, of BaSO 4 or SrSO 4 , under selected experimental conditions. These columns behave like a special type of inorganic exchangers, working by absorption or by ion-isotopic exchange depending on the cases,a nd they provide the means for the selective separation of several important fission products employing very small volumes of fixing and eluting solutions. (Author) 11 refs

Radiolysis of other organic compounds

International Nuclear Information System (INIS)

Pikaev, A.K.

1986-01-01

Peculiarities of radiolysis of organic halogen, phosphorus, sulfur and nitrogen (including amines, amides, nitriles et al.) compounds in liquid phase are discussed. Intermediate and stable finish products of radiolysis of the given compounds, properties and radiochemical yields of these products are considered

Influence of an Intermediate Option on the Description-Experience Gap and Information Search.

Science.gov (United States)

Sharma, Neha; Debnath, Shoubhik; Dutt, Varun

2018-01-01

Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE) gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people's search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people's search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after information search.

Influence of an Intermediate Option on the Description-Experience Gap and Information Search

Directory of Open Access Journals (Sweden)

Neha Sharma

2018-03-01

Full Text Available Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people’s search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people’s search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after

Radiochemical separation of {sup 231}Pa from siliceous cake prior to its determination by gamma ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Dalvi, Aditi A. [Bhabha Atomic Research Centre, Mumbai (India). Analytical Chemistry Div.; Homi Bhabha National Institute, Mumbai (India); Verma, Rakesh

2017-07-01

A simple and fast radiochemical method for the separation of protactinium ({sup 231}Pa) from siliceous cake for its determination by gamma ray spectrometry is described. The method involves (a) a novel approach, the fusion of the siliceous cake with sodium peroxide, (b) the dissolution of the fused mass in nitric acid and (c) the co-precipitation of {sup 231}Pa with manganese dioxide formed in-situ by the addition of solid manganous sulfate and potassium permanganate to the solution. The fusion, effected in a single step, is simpler and highly effective in comparison to methods reported hitherto in literature. The radiochemical yield of {sup 231}Pa, determined using 311.9 keV gamma ray of {sup 233}Pa radiotracer is quantitative (∝90%). The decontamination factors calculated using gamma ray spectrometry and energy dispersive X-ray fluorescence measurements show that the separation from the interfering radionuclides is high whereas separation from major and minor elements is good. Separation by ion-exchange method in hydrochloric acid, hydrofluoric acid and oxalic acid media have comparatively much lower yields. The concentration of {sup 231}Pa in the siliceous cake measured using interference-free 283.6 keV gamma ray was found to be (6.4 ± 0.33) μg kg{sup -1}. The measured concentration of {sup 231}Pa was well above the limit of quantitation whereas the coefficient of variation was ∝5%. The improvement in the limit of detection was due to the reduction in spectral background. Systematic evaluation of various uncertainty parameters showed that the major contributors to the combined uncertainty were efficiency of the high purity germanium detector and the counting statistics. The present sample decomposition and separation methods are robust, simple to perform and can be effectively used for the determination and hence source prospecting of protactinium.

The study of some thiazinic and indaminic dye syntheses induced by ionising radiation

International Nuclear Information System (INIS)

Balestic, S.

1961-03-01

With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [fr

Effect of Intermediate Hosts on Emerging Zoonoses.

Science.gov (United States)

Cui, Jing-An; Chen, Fangyuan; Fan, Shengjie

2017-08-01

Most emerging zoonotic pathogens originate from animals. They can directly infect humans through natural reservoirs or indirectly through intermediate hosts. As a bridge, an intermediate host plays different roles in the transmission of zoonotic pathogens. In this study, we present three types of pathogen transmission to evaluate the effect of intermediate hosts on emerging zoonotic diseases in human epidemics. These types are identified as follows: TYPE 1, pathogen transmission without an intermediate host for comparison; TYPE 2, pathogen transmission with an intermediate host as an amplifier; and TYPE 3, pathogen transmission with an intermediate host as a vessel for genetic variation. In addition, we established three mathematical models to elucidate the mechanisms underlying zoonotic disease transmission according to these three types. Stability analysis indicated that the existence of intermediate hosts increased the difficulty of controlling zoonotic diseases because of more difficult conditions to satisfy for the disease to die out. The human epidemic would die out under the following conditions: TYPE 1: [Formula: see text] and [Formula: see text]; TYPE 2: [Formula: see text], [Formula: see text], and [Formula: see text]; and TYPE 3: [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] Simulation with similar parameters demonstrated that intermediate hosts could change the peak time and number of infected humans during a human epidemic; intermediate hosts also exerted different effects on controlling the prevalence of a human epidemic with natural reservoirs in different periods, which is important in addressing problems in public health. Monitoring and controlling the number of natural reservoirs and intermediate hosts at the right time would successfully manage and prevent the prevalence of emerging zoonoses in humans.

The usefulness of intermediate products of plum processing for alcoholic fermentation and chemical composition of the obtained distillates.

Science.gov (United States)

Balcerek, Maria; Pielech-Przybylska, Katarzyna; Patelski, Piotr; Sapińska, Ewelina; Księżopolska, Mirosława

2013-05-01

In this study, an evaluation of intermediate products of plum processing as potential raw materials for distillates production was performed. Effects of composition of mashes on ethanol yield, chemical composition and taste, and flavor of the obtained spirits were determined. The obtained results showed that spontaneous fermentations of the tested products of plum processing with native microflora of raisins resulted in lower ethanol yields, compared to the ones fermented with wine yeast Saccharomyces bayanus. The supplementation of mashes with 120 g/L of sucrose caused an increase in ethanol contents from 6.2 ± 0.2 ÷ 6.5 ± 0.2% v/v in reference mashes (without sucrose addition, fermented with S. bayanus) to ca. 10.3 ± 0.3% v/v, where its highest yields amounted to 94.7 ± 2.9 ÷ 95.6 ± 2.9% of theoretical capacity, without negative changes in raw material originality of distillates. The concentrations of volatile compounds in the obtained distillates exceeding 2000 mg/L alcohol 100% v/v and low content of methanol and hydrocyanic acid, as well as their good taste and aroma make the examined products of plum processing be very attractive raw materials for the plum distillates production. © 2013 Institute of Food Technologists®

Intermediate structure and threshold phenomena

International Nuclear Information System (INIS)

Hategan, Cornel

2004-01-01

The Intermediate Structure, evidenced through microstructures of the neutron strength function, is reflected in open reaction channels as fluctuations in excitation function of nuclear threshold effects. The intermediate state supporting both neutron strength function and nuclear threshold effect is a micro-giant neutron threshold state. (author)

Intermediate Energy Activation File (IEAF-99)

International Nuclear Information System (INIS)

Korovin, Yu.; Konobeev, A.; Pereslavtsev, P.; Stankovskij, A.; Fischer, U.; Moellendorff, U. von

1999-01-01

Nuclear data library IEAF-99, elaborated to study processes of interactions of intermediate energy neutrons with materials in accelerator driven systems, is described. The library is intended for activation and transmutation studies for materials irradiated by neutrons. IEAF-99 contains evaluated neutron induced reaction cross sections at the energies 0-150 MeV for 665 stable and unstable nuclei from C to Po. Approximately 50,000 excitation functions are included in the library. The IEAF-99 data are written in the ENDF-6 format combining MF = 3,6 MT = 5 data recording. (author)

The effect of selected preparation variables on the radiochemical purity of 99mTc-EDDA-HYNIC-TOC

International Nuclear Information System (INIS)

Betuel Tasdelen

2011-01-01

[ 99m Tc-EDDA-HYNIC-D-Phe 1 , Tyr 3 ]-Ocreotide ( 99m Tc-EDDA-HYNIC-TOC) increasingly emerges to be an alternative tool for somatostatin receptor (SSTR) scintigraphy of neuroendocrine tumours. The high quality of this radiopharmaceutical and its uniformity are very important facts for application of this preparation in clinical practice. Various factors may influence the radiochemical purity (RCP) of certain reagent kits. Some of these include the amount of activity added to the reagent kit, heating time and the age of the formulated kit. The effect of these factors on RCP of 99m Tc-EDDA-HYNIC-TOC has been investigated using high performance liquid chromatography (HPLC) and instant thin layer chromatography (ITLC). (author)

Electron microscopic analysis of rotavirus assembly-replication intermediates

International Nuclear Information System (INIS)

Boudreaux, Crystal E.; Kelly, Deborah F.; McDonald, Sarah M.

2015-01-01

Rotaviruses (RVs) replicate their segmented, double-stranded RNA genomes in tandem with early virion assembly. In this study, we sought to gain insight into the ultrastructure of RV assembly-replication intermediates (RIs) using transmission electron microscopy (EM). Specifically, we examined a replicase-competent, subcellular fraction that contains all known RV RIs. Three never-before-seen complexes were visualized in this fraction. Using in vitro reconstitution, we showed that ~15-nm doughnut-shaped proteins in strings were nonstructural protein 2 (NSP2) bound to viral RNA transcripts. Moreover, using immunoaffinity-capture EM, we revealed that ~20-nm pebble-shaped complexes contain the viral RNA polymerase (VP1) and RNA capping enzyme (VP3). Finally, using a gel purification method, we demonstrated that ~30–70-nm electron-dense, particle-shaped complexes represent replicase-competent core RIs, containing VP1, VP3, and NSP2 as well as capsid proteins VP2 and VP6. The results of this study raise new questions about the interactions among viral proteins and RNA during the concerted assembly–replicase process. - Highlights: • Rotaviruses replicate their genomes in tandem with early virion assembly. • Little is known about rotavirus assembly-replication intermediates. • Assembly-replication intermediates were imaged using electron microscopy

Electron microscopic analysis of rotavirus assembly-replication intermediates

Energy Technology Data Exchange (ETDEWEB)

Boudreaux, Crystal E.; Kelly, Deborah F. [Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA (United States); McDonald, Sarah M., E-mail: mcdonaldsa@vtc.vt.edu [Virginia Tech Carilion School of Medicine and Research Institute, Roanoke, VA (United States); Department of Biomedical Sciences and Pathobiology, Virginia—Maryland Regional College of Veterinary Medicine, Blacksburg, VA (United States)

2015-03-15

Rotaviruses (RVs) replicate their segmented, double-stranded RNA genomes in tandem with early virion assembly. In this study, we sought to gain insight into the ultrastructure of RV assembly-replication intermediates (RIs) using transmission electron microscopy (EM). Specifically, we examined a replicase-competent, subcellular fraction that contains all known RV RIs. Three never-before-seen complexes were visualized in this fraction. Using in vitro reconstitution, we showed that ~15-nm doughnut-shaped proteins in strings were nonstructural protein 2 (NSP2) bound to viral RNA transcripts. Moreover, using immunoaffinity-capture EM, we revealed that ~20-nm pebble-shaped complexes contain the viral RNA polymerase (VP1) and RNA capping enzyme (VP3). Finally, using a gel purification method, we demonstrated that ~30–70-nm electron-dense, particle-shaped complexes represent replicase-competent core RIs, containing VP1, VP3, and NSP2 as well as capsid proteins VP2 and VP6. The results of this study raise new questions about the interactions among viral proteins and RNA during the concerted assembly–replicase process. - Highlights: • Rotaviruses replicate their genomes in tandem with early virion assembly. • Little is known about rotavirus assembly-replication intermediates. • Assembly-replication intermediates were imaged using electron microscopy.

40 keV Shaped electron beam lithography for LIGA intermediate mask fabrication

NARCIS (Netherlands)

Luttge, R.; Adam, D.; Burkhardt, F.; Hoke, F.; Schacke, H.; Schmidt, M.; Wolf, H.; Schmidt, A.

1999-01-01

High precision LIGA masks require a soft X-ray pattern transfer from intermediate masks by means of electron beam lithography. Such a process has been realized using an upgraded Leica ZBA 23 machine with an acceleration voltage of 40 kV. Three process variations of the developer system, so called GG

LWR spent-fuel radiochemical measurements and comparison with ORIGEN2 predictions

International Nuclear Information System (INIS)

Blahnik, D.E.; Jenquin, U.P.; Guenther, R.J.

1988-01-01

The Materials Characterization Center (MCC) at Pacific Northwest Laboratory is responsible for providing characterized spent fuel, designated approved testing material (ATMs) for subsequent use in the investigation of nuclear waste disposal forms by the US Department of Energy geologic repository project. The ATMs are selected to assure that test material is available that has a representative range of characteristics important to spent-fuel behavior in a geologic repository. Burnup and fission gas release were the primary criteria for selecting the ATMs. The five spent-fuel ATMs (ATM-101, -103, -104, -105, and -106) currently being characterized by the MCC have rod average burnups ranging from 20 to 43 MWd/kg M, fission gas releases ranging from 0.2 to 11.2%, and are from both boiling water reactors and pressurized water reactors. Radiochemical analyses of the fuel included measurements of 148 Nd (for fuel burnup), the isotopes of uranium and plutonium, and nuclides of importance to repository performance. Cladding samples were analyzed for 14 C. The measured values of selected nuclides were compared with values obtained from calculations with the ORIGEN2 code that was used to predict isotopic quantities for all of the ATMS. Ratios of the ORIGEN2 calculated values to the measured values for ATM-103 and ATM-106 fuel are given

Compound nuclei, binary decay, and multifragmentation in intermediate-energy heavy-ion reactions

International Nuclear Information System (INIS)

Moretto, L.G.; Wozniak, G.J.

1988-07-01

Hot compound nuclei, frequently produced in intermediate-energy reactions through a variety of processes, are shown to be an important and at times dominant source of complex fragments. 13 refs., 12 figs

FINANCIAL INTERMEDIATION, ENTREPRENEURSHIP AND ECONOMIC GROWTH

OpenAIRE

Wenli Cheng

2007-01-01

This paper presents a simple general equilibrium model of financial intermediation, entrepreneurship and economic growth. In this model, the role of financial intermediation is to pool savings and to lend the pooled funds to an entrepreneur, who in turn invests the funds in a new production technology. The adoption of the new production technology improves individual real income. Thus financial intermediation promotes economic growth through affecting individuals’ saving behaviour and enabl...

Synthesis of [14C]-62514, a radiolabelled derivative of erythromycin A, via [2-14C]N,N-dimethylethylenediamine

International Nuclear Information System (INIS)

Surber, B.W.; Baker, W.R.; Seif, L.

1991-01-01

The synthesis of [ 14 C]A-62514, 11-deoxy-11[carboxy(2-dimethylamino-[1- 14 C]ethyl)amino]-6-0-methyl-e rythromycin A 11,12-(cyclic ester), was performed in five steps. The key intermediate, [2- 14 C]N,N-dimethylethyl-enediamine, was obtained in 80% yield by reacting Eschenmoser's salt with K 14 CN and reducing the resulting [1- 14 C]N,N-dimethylglycinonitrile with H 2 and Raney Ni in methanol and ammonium hydroxide. The final product was obtained 97% radiochemically pure in an overall radiochemical yield of 14%, with a specific activity of 39 mCi/mmol. (author)

Synthesis of 6-[18F] and 4-[18F]fluoro-L-m-tyrosines via regioselective radiofluorodestannylation

International Nuclear Information System (INIS)

Namavari, Mohammad; Satyamurthy, N.; Phelps, M.E.; Barrio, J.R.; California Univ., Los Angeles, CA

1993-01-01

The regioselective radiofluorodestannylation of 6-trimethylstannyl-L-m-tyrosine derivative with [ 18 F]F 2 and [ 18 F]acetyl hypofluorite afforded, after acid hydrolysis, 6-[ 18 F]fluoro-L-m-tyrosine in radiochemical yields of 23 and 17%, respectively. Similarly, 4-[ 18 F]fluoro-L-m-tyrosine was synthesized in 11% radiochemical yield from the corresponding 4-trimethylstannyl-L-m-tyrosine derivative using [ 18 F]F 2 . The structural analyses of precursors, intermediates, and the final products (after 18 F decay), were carried out by 1 H, 13 C, 19 F, 119 Sn-NMR and high resolution mass spectroscopy. (author)

Some Intermediate-Level Violin Concertos.

Science.gov (United States)

Abramson, Michael

1997-01-01

Contends that many violin students attempt difficult concertos before they are technically or musically prepared. Identifies a variety of concertos at the intermediate and advanced intermediate-level for students to study and master before attempting the advanced works by Bach and Mozart. Includes concertos by Vivaldi, Leclair, Viotti, Haydn,…

Direct, coherent and incoherent intermediate state tunneling and scanning tunnel microscopy (STM)

International Nuclear Information System (INIS)

Halbritter, J.

1997-01-01

Theory and experiment in tunneling are still qualitative in nature, which hold true also for the latest developments in direct-, resonant-, coherent- and incoherent-tunneling. Those tunnel processes have recently branched out of the field of ''solid state tunnel junctions'' into the fields of scanning tunnel microscopy (STM), single electron tunneling (SET) and semiconducting resonant tunnel structures (RTS). All these fields have promoted the understanding of tunneling in different ways reaching from the effect of coherence, of incoherence and of charging in tunneling, to spin flip or inelastic effects. STM allows not only the accurate measurements of the tunnel current and its voltage dependence but, more importantly, the easy quantification via the (quantum) tunnel channel conductance and the distance dependence. This new degree of freedom entering exponentially the tunnel current allows an unique identification of individual tunnel channels and their quantification. In STM measurements large tunnel currents are observed for large distances d > 1 nm explainable by intermediate state tunneling. Direct tunneling with its reduced tunnel time and reduced off-site Coulomb charging bridges distances below 1 nm, only. The effective charge transfer process with its larger off-site and on-site charging at intermediate states dominates tunnel transfer in STM, biology and chemistry over distances in the nm-range. Intermediates state tunneling becomes variable range hopping conduction for distances larger than d > 2 nm, for larger densities of intermediate states n 1 (ε) and for larger temperatures T or voltages U, still allowing high resolution imaging

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 1998

Energy Technology Data Exchange (ETDEWEB)

R. C. Bartholomay; B. V. Twining (USGS); L. J. Campbell (Idaho Department of Water Resources)

1999-06-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled 18 sites as part of the fourth round of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. The samples were analyzed for selected radiochemical and chemical constituents. The samples were collected from 2 domestic wells, 12 irrigation wells, 2 stock wells, 1 spring, and 1 public supply well. Two quality-assurance samples also were collected and analyzed. None of the reported radiochemical or chemical constituent concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide- and inorganic-constituent concentrations were greater than the respective reporting levels. Most of the organic-constituent concentrations were less than the reporting levels.

A combined simple bubbling method with high performance liquid chromatography purification strategy, higher radiochemical yield and purity and faster preparation of carbon-11-raclopride.

Science.gov (United States)

Huang, Huacheng; Ning, Yanli; Zhang, Bucheng; Lou, Cen

2015-01-01

Carbon-11-raclopride (¹¹C-R) is a positron-emitting radiotracer successfully used for the study of cognitive control and widely applied in PET imaging. A simple automated preparation of ¹¹C-R by using the reaction of carbon-(11)-methyl triflate (¹¹C-MeOTF) or ¹¹C-methyl iodide (¹¹C-MeI) with demethylraclopride is described. Specifically we used a simple setup applied an additional "U" reaction vessel for ¹¹C-MeOTf compared with ¹¹C-MeI and assessed the influence of several solvents and of the amount of the percussor for ¹¹C-methylation of demethylraclopride by the bubbling method. The reversal of retention order between product and its precursor has been achieved for ¹¹C-R, enabling collection of the purified ¹¹C-R by using the HPLC column after shorter retention time. By the improved radiosynthesis and purification strategy, ¹¹C-R could be prepared with higher radiochemical yield than that of the previous studies. The yield for ¹¹C-MeOTf was 76% and for ¹¹C-CH3I >26% and with better radiochemical purity (>99% based on both ¹¹C-MeOTf and ¹¹C-MeI) as compared to the previously obtained purity of ¹¹C-R using HPLC method with acetonitrile as a part of mobile phase. Furthermore, by using ethanol as the organic modifier, residual solvent analysis prior to human injection could be avoided and ¹¹C-R could be injected directly following simple dilution and sterile filtration. Improved radiosynthesis and HPLC purification in combination with ethanol containing eluent, extremely shortened the time for preparation of ¹¹C-R, gave a higher radiochemical yield and purity for ¹¹C-R and can be used for multiple and faster synthesis of ¹¹C-R and probably for other ¹¹C-labeled radiopharmaceuticals.

Radiochemical determination and separation or total radium, 226Ra and 224Ra; Analisis Radioquimico de Radio total, Radio-226 y Radio-224

Energy Technology Data Exchange (ETDEWEB)

Suarez, J A; Gonzalez, J A; Pablo, M A. de

1987-07-01

Radiochemical purification and separation of radium has been carried out and the determination of total radium solubilized in aqueous samples has been studied assuming that all the alpha emitters of the sample have their origin in the 226Ra and elements of its desintegration chain. Also, the activities of 22Ra and 226 Ra have been evaluated separately doing a measurement after the chemical separation of the radium and another one 10 days after. (Author) 9 refs.

An analytical model for computation of reliability of waste management facilities with intermediate storages

International Nuclear Information System (INIS)

Kallweit, A.; Schumacher, F.

1977-01-01

A high reliability is called for waste management facilities within the fuel cycle of nuclear power stations which can be fulfilled by providing intermediate storage facilities and reserve capacities. In this report a model based on the theory of Markov processes is described which allows computation of reliability characteristics of waste management facilities containing intermediate storage facilities. The application of the model is demonstrated by an example. (orig.) [de

Understanding the mechanism of catalytic fast pyrolysis by unveiling reactive intermediates in heterogeneous catalysis

Science.gov (United States)

Hemberger, Patrick; Custodis, Victoria B. F.; Bodi, Andras; Gerber, Thomas; van Bokhoven, Jeroen A.

2017-06-01

Catalytic fast pyrolysis is a promising way to convert lignin into fine chemicals and fuels, but current approaches lack selectivity and yield unsatisfactory conversion. Understanding the pyrolysis reaction mechanism at the molecular level may help to make this sustainable process more economic. Reactive intermediates are responsible for product branching and hold the key to unveiling these mechanisms, but are notoriously difficult to detect isomer-selectively. Here, we investigate the catalytic pyrolysis of guaiacol, a lignin model compound, using photoelectron photoion coincidence spectroscopy with synchrotron radiation, which allows for isomer-selective detection of reactive intermediates. In combination with ambient pressure pyrolysis, we identify fulvenone as the central reactive intermediate, generated by catalytic demethylation to catechol and subsequent dehydration. The fulvenone ketene is responsible for the phenol formation. This technique may open unique opportunities for isomer-resolved probing in catalysis, and holds the potential for achieving a mechanistic understanding of complex, real-life catalytic processes.

Welding. Performance Objectives. Intermediate Course.

Science.gov (United States)

Vincent, Kenneth

Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

Determination of inorganic pyrophosphatase in rat odontoblast layer by a radiochemical method

International Nuclear Information System (INIS)

Granstroem, G.; Linde, A.

1975-01-01

The enzyme inorganic pyrophosphatase (PPsub(i)ase, EC 3.6.1.1) from the odontoblastic layer of rat incisors has been studied by means of a radiochemical micromethod. The enzyme was incubated with 32 P-pyrophosphate in tris-HCl buffer at 37degC. The reaction was linear with time fr at least 45 min, and the pH optimum was found to be 8.8, independent of the amount of pyrophosphate present. Heating the enzyme at 56degC inhibited the enzyme activity rapidly, Mg 2+ ions activated the enzyme by 15 % at an ion concentration of 4 mM, while higher concentrations were inhibitory. Ca 2+ ions and PO 4 3- ions inhibited the enzyme at all concentrations. F - ions did not affect the PPsub(i)ase at concentrations below 8 mM, whereas higher concentrations had an inhibiting effect. Urea was found to inhibit the enzyme at concentrations above 1.5 M, while EDTA was a strong inhibitor at very low concentrations. The characteristics of PPsub(i)ase agree well with the properties of the enzyme nonspecific alkaline phosphatase (EC 3.1.3.1.) studied earlier. (author)

Intermediate structures in alpha scattering on 28Si nuclei

International Nuclear Information System (INIS)

Kamys, B.; Bobrovska, A.; Budzanovski, A. et al.

1975-01-01

Excitation functions and angular distributions of α-particles scattering on 28 Si nuclei, measured by various authors, are analyzed. Theoretical processing of results is divided into two stages: statistical analysis and analysis in terms of the Regge pole model (RPM). The aim of the statistical analysis is to demonstrate that the structure of excitation curves contains resonance effects. RMP with non-resonance background, described by the optical model (OM), is used to obtain data on properties of intermediate resonances. Autocorrelation functions for one elastic and two inelastic scattering channels are calculated. The mean width of compound states is about 100keV, which is in a good agreement with results of other authores. An analysis of correlation coefficients calculated for all pairs of excitation curves for elastic and two inelastic channels points to the existence of intermediate resonances in each of investigated reaction channels. In the case of large-angle scattering the contribution of potential interaction into the total cross-section is 20-30%, and that of resonance scattering is 50-60%. Energy dependence of Regge pole parameters has also been studied to obtain data on the existence and properties of intermediate resonances

Determination of individual rare earth elements in Vietnamese monazite by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Nguyen Van Suc; Nguyen Mong Sinh

1993-01-01

Radiochemical neutron activation analysis (RNAA) has been applied for determination of rare earth elements (REE) in Vietnamese monazite. The chemical separation procedure used is based on the chromatographic elution of rare earth groups, after the separation of 233 Pa(Th) in irradiated monazite samples by coprecipitation with MnO 2 , the rare earth elements were retained by Biorad AG1 x 8 resin column in 10% 15.4M HNO 3 -90% methanol solution. The elution of heavy rare earth (HREE) and middle rare earth (MREE) groups was carried out with 10% 1M HNO 3 - 90% methanol and 10% 0.05M HNO 3 -90% methanol solution, respectively; while the light rare earths (LREE) were eluted from the column by 0.1M HNO 3 solution. The accuracy of the method was checked by the analysis of granodiorite GSP-I and the rare earth values were in good agreement. (author) 7 refs.; 3 tabs

Transport code and nuclear data in intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Akira; Odama, Naomitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Maekawa, F.; Ueki, K.; Kosaka, K.; Oyama, Y.

1998-11-01

We briefly reviewed the problems of intermediate energy nuclear data file and transport codes in connection with processing of the data. This is a summary of our group in the task force on JENDL High Energy File Integral Evaluation (JHEFIE). In this article we stress the necessity of the production of intermediate evaluated nuclear data file up to 3 GeV for the application of accelerator driven transmutation (ADT) system. And also we state the necessity of having our own transport code system to calculate the radiation fields using these evaluated files from the strategic points of view to keep our development of the ADT technology completely free from other conditions outside of our own such as imported codes and data with poor maintenance or unknown accuracy. (author)

Transport code and nuclear data in intermediate energy region

International Nuclear Information System (INIS)

Hasegawa, Akira; Odama, Naomitsu; Maekawa, F.; Ueki, K.; Kosaka, K.; Oyama, Y.

1998-01-01

We briefly reviewed the problems of intermediate energy nuclear data file and transport codes in connection with processing of the data. This is a summary of our group in the task force on JENDL High Energy File Integral Evaluation (JHEFIE). In this article we stress the necessity of the production of intermediate evaluated nuclear data file up to 3 GeV for the application of accelerator driven transmutation (ADT) system. And also we state the necessity of having our own transport code system to calculate the radiation fields using these evaluated files from the strategic points of view to keep our development of the ADT technology completely free from other conditions outside of our own such as imported codes and data with poor maintenance or unknown accuracy. (author)

Money distribution with intermediation

OpenAIRE

Teles, Caio Augusto Colnago

2013-01-01

This pap er analyzes the distribution of money holdings in a commo dity money search-based mo del with intermediation. Intro ducing heterogeneity of costs to the Kiyotaki e Wright ( 1989 ) mo del, Cavalcanti e Puzzello ( 2010) gives rise to a non-degenerated distribution of money. We extend further this mo del intro ducing intermediation in the trading pro cess. We show that the distribution of money matters for savings decisions. This gives rises to a xed p oint problem for the ...