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"Preparação, caracterização e certificação de materiais de referência isotópicos de urânio" ; PREPARATION, CARACTERIZATION AND CERTIFICATION OF URANIUM ISOTOPE REFERENCE MATERIALS

Oliveira Junior, Olívio Pereira de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/07/2006 PT
Relevância na Pesquisa
26.27%
Este trabalho descreve a preparação, caracterização e certificação de um conjunto de materiais de referência isotópicos de urânio na faixa de 0,5 a 20,0 % de 235U em massa. Os principais conceitos da metrologia em medições químicas foram aplicados para que as propriedades certificadas nos materiais pudessem ser rastreáveis diretamente ao Sistema Internacional de Unidades (SI). Em conseqüência desta abordagem, estes materiais poderão ser utilizados na calibração de instrumentos de medição, avaliação da incerteza de medição, validação de métodos analíticos, avaliação da performance de analistas, rotinas de controle de qualidade e em programas de intercomparação de resultados de medição. As mais avançadas técnicas e métodos de espectrometria de massas, a saber, espectrometria de massas com fonte de gás (GSMS), espectrometria de massas por termoionizacão (TIMS) e espectrometria de massas com fonte de plasma induzido (ICPMS) foram investigadas para identificar quais são os componentes dominantes na incerteza e quantificar a sua contribuição no valor final da incerteza de medição da razão isotópica. Os resultados obtidos foram comparados entre si, para verificar quais técnicas e métodos estão associados aos menores valores de incerteza de medição. A razão isotópica n(235U)/n(238U) nos materiais produzidos foi certificada com incertezas de medição expandidas na faixa de 0...

Desenvolvimento de um sistema eletrônico com registro simultâneo de amplitude e instante de ocorrência dos pulsos aplicado ao método de coincidências 4πβ-γ; Design of an electronic system with simultaneous registering of pulse amplitude and event time applied to the 4πβ-γ coincidence method

Toledo, Fabio de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/11/2009 PT
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26.36%
Em Metrologia Nuclear, há muitos anos, o método absoluto de medida de atividade radioativa por coincidência 4πβ-γ tem sido considerado um padrão primário, em razão de seu alto grau de exatidão e por depender de grandezas observáveis para a obtenção de resultados. O Laboratório de Metrologia Nuclear (LMN), do Instituto de Pesquisas Energéticas e Nucleares (IPEN), dentre suas técnicas de medida, utiliza a metodologia de coincidência 4πβ-γ. Uma nova técnica, conhecida como medida de coincidência por software tem sido empregada na padronização de radionuclídeos, com muitas vantagens sobre a metodologia convencional. Com o objetivo de atualizar sua metodologia de padronização de radionuclídeos, o LMN desenvolveu um novo sistema de medida de coincidências por software, descrito neste trabalho. O sistema eletrônico emprega os mesmos arranjos de detecção beta e gama utilizados em seus sistemas. O novo sistema é constituído por uma placa de aquisição de dados da National Instruments (NI), conectada a um microcomputador e, através de um painel de conexão, aos arranjos de detecção. O gerenciamento é obtido através de software desenvolvido em LabVIEW, proprietária da NI. Este sistema registra as amplitudes e os instantes de ocorrência dos pulsos de detecção beta e gama...

Energias de raios gama padrões: suas covariâncias e relações com as constantes fundamentais; Energy gamma-ray standards: their covariance and relations with the fundamental constants.

Guimarães Filho, Zwinglio de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/08/2004 PT
Relevância na Pesquisa
26.13%
Este trabalho apresenta o procedimento que desenvolvemos e empregamos para determinar os valores a serem adotados para as energias de um conjunto de raios gama comumente utilizados como padrões de calibração, bem como sua respectiva matriz de covariância, esta obtida pela primeira vez. A matriz de covariância entre as energias destes padrões revelou muitos casos de correlações com valores absolutos maiores que 0,8, correlações estas que precisam ser corretamente consideradas para não comprometer a qualidade das análises efetuadas com o uso daquelas energias. No procedimento desenvolvido foi considerada a relação entre as energias dos raios gama (em múltiplos de eV) e as constantes fundamentais das quais dependem: h, e, c e o parâmetro de rede do Silício (aSi), o que possibilitou atualizar os resultados para as constantes fundamentais recomendadas de 2002. Uma metodologia para a inclusão de novos resultados experimentais ao conjunto de padrões de modo a preservar sua auto-consistência também foi desenvolvida neste trabalho. Este método considera adequadamente as covariâncias e atualiza todo o conjunto de padrões para incorporar as novas informações experimentais em uma única etapa. Por fim, utilizamos as metodologias de análise desenvolvidas e o conjunto de padrões aqui recomendados para analisar dados de medidas dos raios gama do decaimento do 233U e...

Metodologia de aquisição de dados e análise por software, para sistemas de coincidências 4πβ-γ e sua aplicação na padronização de radionuclídeos, com ênfase em transições metaestáveis; Data acquisition with software analysis methodology for 4πβ-γ coincidence systems and application in radionuclide standardization, with emphasis on metastable transitions

Brancaccio, Franco
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 06/08/2013 PT
Relevância na Pesquisa
46.32%
O Laboratório de Metrologia Nuclear (LMN) do Instituto de Pesquisas Energéticas e Nucleares (IPEN) desenvolveu recentemente o Sistema de Coincidência por Software (SCS), para a digitalização e registro dos sinais de seus sistemas de coincidências 4πβ-γ utilizados na padronização de radionuclídeos. O sistema SCS possui quatro entradas analógicas independentes que possibilitam o registro simultâneo dos sinais de até quatro detectores (vias β e γ). A análise dos dados é realizada a posteriori, por software, incluindo discriminação de amplitudes, simulação do tempo-morto da medida e definição do tempo de resolução de coincidências. O software então instalado junto ao SCS estabeleceu a metodologia básica de análise, aplicável a radionuclídeos com decaimento simples, como o 60Co. O presente trabalho amplia a metodologia de análise de dados obtidos com o SCS, de modo a possibilitar o uso de detectores com alta resolução em energia (HPGe), para padronização de radionuclídeos com decaimentos mais complexos, com diferentes ramos de decaimento ou com transições metaestáveis. A expansão metodológica tem suporte na elaboração do programa de análise denominado Coincidence Analyzing Task (CAT). A seção de aplicação inclui as padronizações do 152Eu (diferentes ramos de decaimento) e do 67Ga (nível metaestável). A padronização do 152Eu utilizou uma amostra de uma comparação internacional promovida pelo BIPM (Bureau International des Poids et Mesures)...

Determination of Aldrin Purity Using a Combination of the Mass Balance Approach and Quantitative NMR

Rodrigues,Janaína M.; Rego,Eliane C. P.; Guimarães,Evelyn F.; Sousa,Marcus V. B.; Monteiro,Tânia M.; Neves,Laura A.; Violante,Fernando G. M.; Almeida,Renato R. R.; Quaresma,Maria C. B.; Nogueira,Raquel
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 EN
Relevância na Pesquisa
26.11%
This paper describes the studies performed to determine the purity of aldrin samples, an organochlorine pesticide, using the mass balance approach. The organic impurities were identified and quantified by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detection (GC-FID) and gas chromatography with electron capture detector (GC‑µECD) using two columns: DB-35ms (intermediate polarity) and DB-XLB (low polarity). The water content was determined by Karl Fischer coulometric titration, and the inorganics were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The aldrin contents determined by mass balance and quantitative nuclear magnetic resonance (qNMR) were compared. The obtained results were validated through the participation of the National Institute of Metrology, Quality and Technology (Inmetro) in the key-comparison CCQM-K55.b organized by the Organic Analysis Working Group/International Bureau of Weights and Measures (OAWG/BIPM).

Entanglement and Metrology With Singlet-Triplet Qubits

Shulman, Michael Dean
Fonte: Harvard University Publicador: Harvard University
Tipo: Thesis or Dissertation; text Formato: application/pdf
EN
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Electron spins confined in semiconductor quantum dots are emerging as a promising system to study quantum information science and to perform sensitive metrology. Their weak interaction with the environment leads to long coherence times and robust storage for quantum information, and the intrinsic tunability of semiconductors allows for controllable operations, initialization, and readout of their quantum state. These spin qubits are also promising candidates for the building block for a scalable quantum information processor due to their prospects for scalability and miniaturization. owever, several obstacles limit the performance of quantum information experiments in these systems. For example, the weak coupling to the environment makes inter-qubit operations challenging, and a fluctuating nuclear magnetic field limits the performance of single-qubit operations. The focus of this thesis will be several experiments which address some of the outstanding problems in semiconductor spin qubits, in particular, singlet-triplet (S-T0) qubits. We use these qubits to probe both the electric field and magnetic field noise that limit the performance of these qubits. The magnetic noise bath is probed with high bandwidth and precision using novel techniques borrowed from the field of Hamiltonian learning...

LYRA Irradiation Experiments - Neutron Metrology and Dosimetry

ACOSTA IBORRA BEATRIZ; DEBARBERIS LUIGI
Fonte: World Scientific Publishing Co. Pte. Ltd. Publicador: World Scientific Publishing Co. Pte. Ltd.
Tipo: Contributions to Conferences Formato: Printed
ENG
Relevância na Pesquisa
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LYRA is a dedicated rig for materials irradiation in the High Flux Reactor in Petten, the Netherlands. The LYRA facility is located at the HFR¿s Pool Side Facility. The irradiation rig comprises a tungsten gamma shielding, and the irradiation capsule itself. The capsule is foreseen of a heater box that forming a small oven allows for irradiation of large number of samples at very low thermal gradients and if required in-pile annealing. LYRA has been designed for the purpose of studying the irradiation damage of nuclear reactor pressure vessel materials. LYRA began its operation in 1997 and has been now operated for 10 years, holding already 10 irradiation campaigns. In this paper the different LYRA irradiation experiments, their results from the neutron metrology as well as the doses build-up point of view are presented.; JRC.F.2-Cleaner energy

Implementation of Guide to the Expression of Uncertainty in Measurement (GUM) to Multi-Collector TIMS Uranium Isotope Ratio Metrology

BÜRGER S.; ESSEX R.m.; MATHEW K.j.; RICHTER Stephan; THOMAS R. B.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Articles in Journals Formato: Printed
ENG
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The application of the GUM (Guide to the expression of Uncertainty in Measurement) to calculate standard uncertainties for routing uranium isotope mass spectrometry measurements for nuclear safeguards and nuclear metrology is introduced. The benefit of this approach is an improved coherency and transparency of the uncertainty calculation, which should include contributions from all potentially significant sources of uncertainty to the mass spectrometric measurement result. The GUM approach puts the responsibility for quantifying the uncertainty on the analyst who makes the measurements and not with the user of the data. The uncertainty budget also serves to provide a feedback to the analyst. It identifies the dominant components of the measurement uncertainty and allows for better understanding, management, and improvement of the measurement process. Detailed examples of uncertainty calculations are presented for the most common types of uranium isotope measurements by multi-collector thermal ionization mass spectrometry (TIMS); e.g., total evaporation, conventional Faraday cup measurements using internal normalization, and combined measurements using a secondary electron multiplier and Faraday cups. Various sources of uncertainty common to multi-collector TIMS...

Preface to ICRM2011 - Proceedings of the 18th International Conference on Radionuclide Metrology and its Applications

DE FELICE P.; HINO Y.; MARINGER F.-J.; WAETJEN Uwe
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Contributions to Conferences Formato: Printed
ENG
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This preface to the Proceedings volume summarizes the objectives and outcomes of the conference ICRM 2011, and gives additional information on the working of the International Committee for Radionuclide Metrology.; JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Advanced metrology for new generation nuclear power plants

JOHANSSON L.; FILTZ J.-R.; DEFELICE P.; SADLI M.; PLOMPEN Arjan; HAY B.; DINSDALE A.; POMME Stefaan; CASSETTE P.; KEIGHTLEY J.
Fonte: Metrology Consulting Publicador: Metrology Consulting
Tipo: Contributions to Conferences Formato: CD-ROM
ENG
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36.42%
This EMRP (European Metrology Research Programme) project is looking at solving metrological problems related to a new generation of nuclear power plants. The proposed Generation IV power plants are designed to run safely, make efficient use of natural resources, minimize the waste and maintain proliferation resistance. In order to reach these goals, the reactor operation involves higher temperatures, high-energy neutron fluence, different types of fuel where the minor actinides are also used as fuel etc. In this multidisciplinary project, which has 12 partners in 10 countries, the work is focused on improved temperature measurements, investigation of thermal properties of advanced materials, determination of new and relevant nuclear data and development of measurement techniques for radionuclides suitable for Generation IV power plants.; JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

100 years of radionuclide metrology

JUDGE S.; ARNOLD D.; CHAUVENET B.; COLLÉ R.; DE FELICE P.; GARCIA-TORANO Eduardo; WAETJEN Uwe
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Contributions to Conferences Formato: Printed
ENG
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The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In the early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics.; JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Proceedings of the 19th International Conference on Radionuclide Metrology and its Applications, 17–21 June 2013, Antwerp, Belgium

Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Contributions to Conferences Formato: Printed
ENG
Relevância na Pesquisa
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This special issue of Applied Radiation and Isotopes is devoted to the 19th International Conference on Radionuclide Metrology and its Applications (ICRM 2013), which was held from 17 - 21 June 2013 at the Congress Centrum Elzenveld in Antwerp, Belgium. The conference was organised by the European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (EC-JRC-IRMM), the local organisation was undertaken by the Radionuclide Metrology group of JRC-IRMM. The 19th International Conference on Radionuclide Metrology and its Applications (ICRM 2013) was attended by 178 participants from 42 countries worldwide. Of the 166 submitted abstracts, 2 invited talks, 39 oral contributions and 76 posters were presented at the symposium. 104 papers are published in these proceedings, accepted after a very rigorous reviewing process.; JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Preparation of high-resolution 238U alpha-sources by electrodeposition from various electrolyte solutions

JOBBAGY VIKTOR; CRESPO M. T.; VAN AMMEL Raf; MAROULI MARIA; MOENS Andre; POMME Stefaan; GARCÍA-TORAÑO E.
Fonte: Metrology Consulting Publicador: Metrology Consulting
Tipo: Contributions to Conferences Formato: Printed
ENG
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In this paper the source preparation procedure for high-resolution 238U sources is described. This work was done in a collaboration between CIEMAT and IRMM within the frame of MetroFission, a project of the European Metrology Research Programme, in order to determine the alpha-emission probabilities of 238U. 238U was deposited from organic (iso-propanol) and inorganic (H2SO4/(NH4)2SO4, saturated NH4NO3) electrolyte solutions on metal backings. Preliminary results show that the 238U source quality is significantly better when making them in saturated NH4NO3 than in the two other electrolytes. By this method sources of 18,6-22 mm diameter, 26 μg cm-2 surface density, 16-18 keV resolution and a peak to valley ratio higher than 50 could be made. This reconciles the inherently opposing requirements of high resolution and sufficient count rate needed to determine the alpha–emission probabilities accurately.; JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Metrology for new generation nuclear power plants - MetroFission

JOHANSSON L.; FILTZ J.-R.; DE FELICE P.; SADLI M.; PLOMPEN Arjan; HEYSE JAN; HAY Bruno; DINSDALE A.; POMME Stefaan; CASSETTE P.; KEIGHTELY John
Fonte: IEEE Publicador: IEEE
Tipo: Contributions to Conferences Formato: Online
ENG
Relevância na Pesquisa
26.36%
This EMRP (European Metrology Research Programme) project, MetroFission, has been looking at solving metrological problems related to a new generation of nuclear power plants. The proposed Generation IV power plants are designed to run safely, make efficient use of natural resources, minimize the waste and maintain proliferation resistance. In order to reach these goals, the reactor operation involves higher temperatures, high-energy neutron fluence, different types of fuel where the minor actinides are included etc. In this multidisciplinary project, which has 12 partners in 10 countries, the work has focused on improved temperature measurements, investigation of thermal properties of advanced materials, determination of new and relevant nuclear data and development of measurement techniques for radionuclides suitable for Generation IV power plants. The improved temperature measurement for nuclear power plant applications includes the development of a new Fe-C fixed point. Robust, repeatable and versatile cells have been constructed and compared with success among the project participants and their melting temperatures have been determined. Furthermore, the methodology of self-validating thermocouples has proven efficient at several fixed point temperatures (Au...

Analytical methods: Improvements, advancements and new horizons

Keen, C.; Jue, T.; Tran, C.; Vogel, J.; Downing, R.; Iyengar, V.; Rucker, R.
Fonte: Amer Inst Nutrition Publicador: Amer Inst Nutrition
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
26.21%
The workshop and exhibits dealing with analytical methods were selected to highlight the current state of the art in elemental analysis. The presentations in the first part of the workshop described approaches and advances important to the analysis of trace minerals. These presentations included: 1) two approaches to mass spectrometry, inductively coupled plasma and accelerator mass spectrometry; 2) use of nuclear magnetic resonance in studies of mineral function; and 3) the use and limitations of fluorescent probes in studies of metal uptake and regulation. In the second part of the workshop, the International Atomic Energy's contributions to nutritional "metrology" were described. Advances in instrumentation over the past decade have led to extraordinary improvements in the precision and sensitivity of mineral analyses. The ability to address isotopic speciation at such low levels sets the stage for numerous novel approaches in the assessment of trace mineral function.; Carl L. Keen, Thomas Jue, Cuong D. Tran, John Vogel, R. Gregory Downing, Venkatesh Iyengar and Robert B. Rucker; Copyright © 2003 by American Society for Nutritional Sciences.

Radio Frequency Phototube, Optical Clock and Precise Measurements in Nuclear Physics

Margaryan, Amur
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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Recently a new experimental program of novel systematic studies of light hypernuclei using pionic decay was established at JLab (Study of Light Hypernuclei by Pionic Decay at JLab, JLab Experiment PR-08-012). The highlights of the proposed program include high precision measurements of binding energies of hypernuclei by using a high resolution pion spectrometer, HpiS. The average values of binding energies will be determined within an accuracy of ~10 keV or better. Therefore, the crucial point of this program is an absolute calibration of the HpiS with accuracy 10E-4 or better. The merging of continuous wave laser-based precision optical-frequency metrology with mode-locked ultrafast lasers has led to precision control of the visible frequency spectrum produced by mode-locked lasers. Such a phase-controlled mode-locked laser forms the foundation of an optical clock or femtosecond optical frequency comb (OFC) generator, with a regular comb of sharp lines with well defined frequencies. Combination of this technique with a recently developed radio frequency (RF) phototube results in a new tool for precision time measurement. We are proposing a new time-of-flight (TOF) system based on an RF phototube and OFC technique. The proposed TOF system achieves 10 fs instability level and opens new possibilities for precise measurements in nuclear physics such as an absolute calibration of magnetic spectrometers within accuracy 10E-4 - 10E-5.

Quantum discord determines the interferometric power of quantum states

Girolami, Davide; Souza, Alexandre M.; Giovannetti, Vittorio; Tufarelli, Tommaso; Filgueiras, Jefferson G.; Sarthour, Roberto S.; Soares-Pinto, Diogo O.; Oliveira, Ivan S.; Adesso, Gerardo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.21%
Quantum metrology exploits quantum mechanical laws to improve the precision in estimating technologically relevant parameters such as phase, frequency, or magnetic fields. Probe states are usually tailored on the particular dynamics whose parameters are being estimated. Here we consider a novel framework where quantum estimation is performed in an interferometric configuration, using bipartite probe states prepared when only the spectrum of the generating Hamiltonian is known. We introduce a figure of merit for the scheme, given by the worst case precision over all suitable Hamiltonians, and prove that it amounts exactly to a computable measure of discord-type quantum correlations for the input probe. We complement our theoretical results with a metrology experiment, realized in a highly controllable room-temperature nuclear magnetic resonance setup, which provides a proof-of-concept demonstration for the usefulness of discord in sensing applications. Discordant probes are shown to guarantee a nonzero precision in the estimation procedure for different generating Hamiltonians, while classically correlated probes are unable to accomplish the estimation in a worst case setting. This work establishes a rigorous and direct operational interpretation for general quantum correlations...

Quantum metrology and its application in biology

Taylor, Michael A.; Bowen, Warwick P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.35%
Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance to biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context, focusing on optical techniques due to their particular relevance for biological imaging, sensing, and stimulation. Our understanding of quantum mechanics has already enabled important applications in biology, including positron emission tomography (PET) with entangled photons, magnetic resonance imaging (MRI) using nuclear magnetic resonance, and bio-magnetic imaging with superconducting quantum interference devices (SQUIDs). In quantum metrology an even greater range of applications arise from the ability to not just understand, but to engineer, coherence and correlations at the quantum level. In the past few years, quite dramatic progress has been seen in applying these ideas into biological systems. Capabilities that have been demonstrated include enhanced sensitivity and resolution, immunity to imaging artifacts and technical noise, and characterization of the biological response to light at the single-photon level. New quantum measurement techniques offer even greater promise...

Calibration and alignment of metrology system for the Nuclear Spectroscopic Telescope Array mission

Liebe, Carl Christian; Craig, William; Kim, Yunjin; McLean, Ryan; Meras, Patrick, Jr.; Raffanti, Michael; Scholz, Christopher
Fonte: Society of Photo-optical Instrumentation Engineers Publicador: Society of Photo-optical Instrumentation Engineers
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em /04/2012
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26.4%
A metrology system to measure the on-orbit movement of a ten meter mast has been built for the Nuclear Spectroscopic Telescope Array (NuSTAR) x-ray observatory. In this paper, the metrology system is described, and the performance is measured. The laser beam stability is discussed in detail. Pre-launch alignment and calibration are also described. The invisible infrared laser beams must be aligned to their corresponding detectors without deploying the telescope in Earth’s gravity. Finally, a possible method for in-flight calibration of the metrology system is described.

Modelagem sociotécnica de uma organização nuclear: estudo de caso aplicado ao laboratório Nacional de Metrologia das Radiações Ionizantes; Sociotechnical modelling of a nuclear organization case study applied to the Ionizing Radiation Metrology National laboratory

Acar, Maria Elizabeth Dias
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/11/2015 PT
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Uma metodologia que combina mapeamento e análise de processos, elicitação, mapeamento e análise crítica de conhecimentos e análise sociotécnica com base em análise de redes sociais foi concebida. A metodologia foi aplicada à uma pequena organização intensiva conhecimento LNMRI e permitiu a avaliação dos seus principais ativos intelectuais e sua capacidade de evoluir. Nesse sentido, com base em questões reais, tal como a saída de pessoas da organização, foram avaliados os impactos de prováveis cenários futuros. Para tal tarefa, foi analisada uma rede multimodal de processos, objetos de conhecimento e pessoas, utilizando-se um conjunto apropriado de métricas e meios, incluindo a avaliação das esferas de influências de nós chave. Para diferenciar a capacidade das pessoas em desempenhar diferentes papeis nos processos, alguns atributos dos nós foram utilizados como critérios de partição da rede, proporcionando assim, a capacidade de diferenciar o impacto da perda potencial de supervisores e operadores. A metodologia proposta possibilitou: i) a identificação de objetos de conhecimento e de suas fontes; ii) a classificação desses objetos segundo sua relevância; iii) a avaliação de vulnerabilidades da estrutura da rede LNMRI e iv) revelou os mecanismos informais de partilha de conhecimento. A metodologia concebida demonstrou ser uma ferramenta robusta para um amplo diagnóstico para subsidiar o planejamento de sucessão e também o planejamento estratégico organizacional.; A methodology combining process mapping and analysis; knowledge elicitation mapping and critical analysis; and sociotechnical analysis based on social network analysis was conceived. The methodology was applied to a small knowledge intensive organization LNMRI...