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Alessandra Licursi Maia C.da Cunha,Roberta Lourenço Ziolli, Ricardo Queiroz Aucélio
MULTIVARIATE OPTIMIZATION AIMING THE DEVELOPMENT AND VALIDATION OF A SELECTIVE ROOM-TEMPERATURE PHOSPHORIMETRIC METHOD FOR THE DETERMINATION OF CHRYSENE

In this work, a factorial design was applied for the development and validation of a solid surface roomtemperature phosphorimetric method aiming the selective determination of chrysene. Data analysis was made using several strategies: statistical experimental analysis (testing the significance of the factors using the analysis of variation, F-test and t-test), graphic method (Pareto´s chart) and the evaluation of the interactions among all variables. This procedure aimed the achievement of high accuracy of results and minimization of the time spent for optimization. A statistical program was used as a supporting tool. As the result, the experimental conditions selected for the determination of chrysene were: use of silver (I) as the selective phosphorescence inducer (applied as single 5 µL spike of Ag+ solution in the concentration range between 0,03 and 0,05 mol L-1); Basic pH of the analyte solution (NaOH 0,002 mol L-1); use of SDS as the substrate surface modifier (employed as single 5 µL of a SDS (Sodium Dodecyl Sulphate) solution between 0,25 and 0,50 mol L-1). The optimized method is highly selective towards the presence of pyrene and allowing the detection of an effective mass of chrysene in the ng range (based on the absolute limit detection, ALOD).

Akie K. Ávila, Renata M. H. Borges, Thiago de O. Araujo, Maria Cristina B. Quaresma, Fabio S. Bazilio, Lígia C. C. Oliveira
FIRST ROUND OF THE PROFICIENCY TEST SCHEME ON BRAZILIAN CACHAÇA

Cachaça is the Brazilian most popular spirit and the quality of analytical results is essential for protection of consumers and to expand the international acceptance of the product. The first round of the proficiency-testing scheme (interlaboratory study), Brazilian cachaça, was carried out between November 2004 and March 2005. The blended sample was prepared for this round containing several components, including copper, methanol and ethyl carbamate. The aim of this paper is to evaluate the laboratory performance on the determination of the copper concentration in Brazilian cachaça. Eleven laboratories reported results for copper; these results were compared to the reference value attributed by Inmetro in partnership with The Laboratory of the Government Chemist – LGC from the United Kingdom and with the consensus value. A comparison between these values was made to determine which approach could guarantee better reliability to the conclusions taken from the PT scheme. The samples used have shown good homogeneity and stability, the reference value attributed by Inmetro and LGC is SI traceable and showed to be more appropriate to be used as the conventional true value than the consensus value calculated with the participants’ results.

Kimmo Latva-Käyrä, Risto Ritala
OPTIMISING A MEASUREMENT SETUP FOR DECISION MAKING

Measurements are the key to rational decision making. Measurement information generates value, when it is applied in the decision making. An investment cost and maintenance costs are associated with each component of the measurement system. Clearly, there is – under a given set of scenarios – a measurement setup that is optimal in expected (discounted) utility. Contrary to process design, design of measurement and information systems has not been formulated as such an optimization problem, but rather been tackled intuitively. In this presentation we propose a framework for analyzing such an optimization problem. Our framework is based on that the basic mechanism of measurement is reduction of uncertainty about reality. Statistical decision theory serves as the basis for analyzing decision making. In this paper we apply the framework to a problem that is rather simple but of practical importance: how to arrange laboratory quality measurements optimally. In particular, we discuss a case in the paper making industry, in which the product quality is measured with automated quality analyzers and by laboratory measurements.

Jaime M. Ticona, Mauricio N. Frota
ECONOMIC IMPACT OF QUALITY CERTIFICATION OF INDUSTRIAL PRODUCTS ON THE BRAZILIAN DOMESTIC MARKET

Abstract: This work reviews the economics of standards, conformity assessment procedures and the trade of Brazilian industrial products. It also evaluates the associated economic impact resulted from their product certification based on international best practices. Four leading products were chosen: steel, bus coachwork, automotive tires and cement. The production time series of these products (made available by governmental agencies) were fitted by means of the multiple linear regression method. The method was successfully applied at a 5% level of significance (a probability value –p-value– lower than 0.05 guarantees the existence of non-zero polynomial coefficients).
The simulation investigated the combined economic impact of (i) the regionalization process that has led to the establishment of a common market in the South Cone (Mercosur); (ii) the exposure of the Brazilian market to international trade competition (the opening up of the Brazilian economy in the 1990’s); (iii) product certification and (iv) the monetary inflation in Brazil, in the period. Each individual impact was documented. The product certification proved to be beneficial as 15.1% growth in production of cement, 12.4 % in steel, 11% in automotive tires and 13.3 % in bus coachwork were observed.

I.Bal, W.Klonowski
APPLICATION OF NONLINEAR DYNAMICS METHODS FOR MEASURING CHARACTERISTICS OF BIOSIGNALS AND QUALITY OF MATERIALS’ SURFACES IN "SENSATION" PROJECT

We present FP6. Integrated Project SENSATION and works done by our Group on application of nonlinear dynamics for analysis of biosignals measured by new nanosensors for vigilance monitoring and for biomedical applications.

José Eduardo Manzoli, Paulo Roberto Rela, Juliana Silva Félix, Magali Monteiro
INITIAL CONCENTRATION PROFILE INFLUENCE ON MIGRATION MEASUREMENTS FROM PLASTIC PACKAGING: A SIMULATION STUDY

Migration of components from plastic packaging into foodstuffs or into medicines is a very important issue, concerning public health. Using experimental techniques, like gas chromatography-mass spectrometry, these essays measure total migration and specific migration of components from plastic packaging. This work presents an explanation and applications of a numerical technique tool for this measurement, allowing the comprehension of the diffusion process and the estimate of component migration in difficult or impractical measurements. As an application example, the non-uniform influence of initial concentration profile on the migration is presented, demonstrating the necessity of this profile determination for high quality considerations on involved metrology.

I. Frollo, P. Andris, V. Juráš, Z. Majdišová
MAGNETIC FIELD DISTRIBUTION MEASUREMENT OF THIN-LAYERS USING MAGNETIC RESONANCE IMAGING SEQUENCES

Magnetic field distribution measurement and imaging of thin layers using magnetic resonance techniques on biological samples have been performed. The resultant image represents the magnetic susceptibility distribution in the sample. An NMR imaging method susceptible to the homogeneity of magnetic field Gradient Echo was used. Since the investigated physical or biological samples did not generate any NMR signal, a homogeneous phantom (reference medium) was used - a container filled with water - as a medium. An image acquired by this method is actually a projection of the sample properties onto the homogeneous phantom. The method could be applied in nanotechnology, microelectronics and especially in the biological and medical sciences.

Gerhard Linss, Susanne C N Töpfer, Uwe Nehse
AUTOMATIC EXECUTION OF INSPECTION PLANS FOR KNOWLEDGE-BASED DIMENSIONAL MEASUREMENTS OF MICRO- AND NANOSTRUCTURED COMPONENTS

Due to the fast advancement of manufacturing technologies for micro- and nanostructured components the need for sophisticated inspection methods increases. The paper on hand discusses the prerequisites for automatic execution of inspection plans. Main goal is to enable automated dimensional measurements of micro- and nanostructured components instead of executing functional tests. Besides reducing manufacturing cost this approach enables the setup of a closed quality loop which allows a higher level of efficiency. It provides a constant feedback to the manufacturing processes and to the design process. Based on the latest state-of-the-art the setup and operating principle of a closed quality loop for dimensional inspections is described. Vital part of the closed quality loop is a multisensor system consisting of adaptive, intelligent sensors with cascaded measuring ranges. The paper provides a novel and consistent overall view of dimensional inspections of micro- and nanostructured components and how they will be executed in the future. This paper shall deliver a significant contribution to the birth of industrial nanometrology which must overcome the limitations of research oriented nanometrology.

Klaus-Dieter Sommer, Albert Weckenmann, Bernd R. L. Siebert, Stefan Heidenblut, Karina Weißensee
A SYSTEMATIC MODELLING CONCEPT FOR UNCERTAINTY ANALYSIS

The evaluation of measurement uncertainty is based on both, the knowledge about the measuring process and the quantities which influence the measurement result. The knowledge about the measuring process is represented by the model equation which expresses the interrelation between the measurand and the input quantities. Therefore, the modeling of the measurement is a key element of modern uncertainty evaluation. A practical modeling concept has been developed that is based on the idea of the measuring chain. It gets on with only a few generic model structures. From this concept, a practical stepwise procedure has been derived.

S. H. Khan, L. Finkelstein
GENERIC PROBLEMS AND ADVANCES IN THE COMPUTER AIDED DESIGN OF INSTRUMENTS AND INSTRUMENT ELEMENTS

The paper is based on a long-term programme of research on mathematical modelling and computer aided design of instruments and instrument elements in the Measurement and Instrumentation Centre of City University London. It considers the principal generic problems of computer aided design of instrument systems and aspects of the research agenda that arises from them. It describes recent advances in the computer aided design of sensors and actuators.

Page 841 of 912 Results 8401 - 8410 of 9113