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ortho-Oxo substituted trans 2,3-diaryloxiranes were regio- and stereoselectively arylated by arylzinc reagents, obtained from the corresponding boronic acids by B–Zn exchange. The reaction was quite general, irrespective to the aryl nucleophile and proceeded via a ring opening at the α-carbon with respect to the substituted aryl ring. The stereoselectivity was from high to complete toward the alcohol resulted from retention of configuration at the electrophilic carbon. The method allowed a direct and high yielding access to trans 2,3-diphenyl-2,3-dihydrobenzofuran, which is a key structural motif in resveratrol dimers as viniferins. The use of enantioenriched starting diaryloxiranes resulted in no loss of stereochemical integrity in the final trans 2,3-dihydrobenzofuran, which was characterized for the first time in enantioenriched form.

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A cognição humana é algo que desperta o interesse do homem desde os primórdios de sua história. No entanto, muitos processos cognitivos ainda não podem ser explicados pela ciência. Neste contexto, esta dissertação propõe um estudo sobre as reações do sistema nervoso por meio de estímulos ao sistema cognitivo. Mais especificamente, a proposta foi utilizar técnicas de processamento de sinais e estatística multivariada para avaliar a intensidade de esforço mental e o desempenho cognitivo por meio da mensuração do diâmetro pupilar. Este trabalho realizou dois experimentos cognitivos, onde os voluntários foram submetidos a estímulos visuais ao mesmo tempo em que era adquirido o sinal pupilar. Ambos experimentos contaram com um teste cognitivo computadorizado e foram aplicados utilizando um equipamento de rastreamento ocular, um microcomputador e um software de apoio para apresentação do estimulo e calibração do equipamento. Os dados coletados foram tratados e processados com o auxílio de duas plataformas de desenvolvimento para processamento de sinais e computação estatística. Os resultados alcançados apontam que existe uma relação entre a carga cognitiva e a variação do diâmetro pupilar, mostrando que a pupila é um indicador sensível ao esforço mental. Como contribuição original, os resultados também mostram que é possível projetar classificadores estatísticos para predizer automaticamente o desempenho de humanos em tarefas cognitivas, se tal predição, considerar os sinais pupilares como um todo e não somente um resumo de sua variação Human cognition is something that has aroused the interest of man since the dawn of its history. However, many cognitive processes cannot yet be explained by science. In this context, this dissertation proposes a study on the reactions of the nervous system through stimuli to the cognitive system. More specifically, the proposal was to use of signals processing techniques and multivariate statistic to assess mental effort intensity and cognitive performance through measurement of the pupillary diameter. This work carried out two cognitive experiments, where the volunteers were submitted to visual stimuli at the same time that the pupillary signal was acquired. Both experiments had a computerized cognitive test and were applied using an eye tracking equipment, a microcomputer and support software to present equipment stimulation and calibration. The data collected were treated and processed with the aid of two development platforms for signal processing and statistical computation. The results achieved show that there is a relationship between the cognitive load and pupillary diameter variation, showing that the pupil is an indicator sensitive to mental effort. As an original contribution, the results also show that it is possible to design statistical classifiers to automatically predict the performance of humans in cognitive tasks, if such a prediction, to consider the pupillary signals as a whole and not only a summary of their variation

Made available in DSpace on 2018-12-11T17:02:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-04-01. Added 1 bitstream(s) on 2019-10-09T18:30:23Z : No. of bitstreams: 1 S1519-69842016000200396.pdf: 935043 bytes, checksum: 30e1c6cf1812a18529c3d1609b80ac7d (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The effects of seasonal variations and the methods of collection of propolis produced by Africanized honey bees Apis mellifera Linnaeus, 1758, on the composition of constituent minerals such as magnesium (Mg), zinc (Zn), iron (Fe), sodium (Na), calcium (Ca), copper (Cu), and potassium (K) were evaluated. Propolis was harvested from 25 beehives by scraping or by means of propolis collectors (screen, “intelligent” collector propolis [ICP], lateral opening of the super [LOS], and underlay method). During the one-year study, the propolis produced was harvested each month, ground, homogenized, and stored in a freezer at -10 ºC. Seasonal analyses of the mineral composition were carried out by atomic absorption spectrophotometry and the results were evaluated by analysis of variance (ANOVA), followed by Tukey-Kramer’s test to compare the mean values (p

Solutions to the OECD/NEA three-dimensional fuel assembly benchmark problem, C5G7MOX, obtained using the discrete-¨ordinates neutron transport code TORT are presented, The accuracy and convergence of the effective multiplication factor and maximum pin power are examined while varying the fidelity of the geometric mode! and the order of the angular quadrature, specifically the Square Legendre-Chebychev quadrature. The calculated value of the effective multiplication factor is shown to converge asymptotically as the order of the quadrature is increased. The behavior of that asymptotic limit of keff with decreasing computational cell size and increasing staircase resolution of the curved rod-moderator is less converged, Moreover, rapidly increasing computational cost with geometric configuration refinement prevented us from achieving asymptotic convergence with the spatial approximation. The maximum pin power results are generally shown to asymptotically converge to within the statistical error of the reference solution for the problem slices where control rods are not present. For the zones that contain control rods, the solution does not appear to be tightly converged for the meshes and quadrature orders employed.

BOT3P consists of a set of standard FORTRAN 77 language programs that gives the users of the deterministic transport codes DORT, TORT, TWODANT, THREEDANT, PARTISN and the sensitivity code SUSD3D some useful diagnostic tools to prepare and check the geometry of their input data files for both Cartesian and cylindrical geometries, including graphical display modules. Users can produce the geometrical and material distribution data for all the cited codes far both two-dimensional (2D) and three¨dimensional (3D) applications and, only in 3D Cartesian geometry, far the Monte Carlo Transport Code MCNP, starting from the same BOT3P input. Moreover, BOT3P stores the fine mesh arrays and the material zone map in a binary file, the content of which can be easily interfaced to any deterministic and Monte Carlo transport code. This makes it possible to compare directly for the same geometry the effects stemming from the use of different data libraries and solution approaches on transport analysis results. BOT3P Version 5.0 lets users optionally and with the desired precision compute the area/volume error of material zones with respect to the theoretical values, if any, because of the stair-cased representation of the geometry, and automatically update material densities on the whole zone domains to conserve masses. A local (per mesh) density correction approach is also available. BOT3P is designed to run on Linux/UNIX platforms and is publicly available from OECD/NEA Data Bank. Through the use of BOT3P, radiation transport problems with complex 3D geometrical structures can be modelled easily, as a relatively small amount of engineer-time is required and refinement is achieved by changing few parameters. This tool is useful far solving very large challenging problems, as successfully demonstrated not only in some complex neutron shielding and criticality benchmarks but also in a power reactor application.

This work was carried out by Ansaldo Nucleare in co-operation with the Nuclear Data Group of the ENEA/FIS-NUC Section and represents an example of a heavy and complex industrial application simulated with the TORT 3D deterministic transport code, supported by the BOT3P pre-post-processor system far the automatic spatial mesh generation and graphical verification. It is underlined that the development and validation of BOT3P was originally performed in ENEA-Bologna.

We present a comprehensive study of the solution error far the C5G7MOX Benchmark problem using the two-dimensional transport code DORT. We set a stringent criterion that a successful solution to the benchmark exercise must satisfy, namely that at least far some of the benchmark quantities convergence to the reference solution with computational model refinement must be demonstrated. In the present exercise this amounts to examining the evolution of the DORT solution, e.g. the multiplication factor, with increasing angular quadrature order, decreasing computational cell size, and tighter representation of the curved rod-moderator interface for all circular rods in the care model. In addition we explored the effect of angular quadrature type, comparing solution accuracy far the fully symmetric and the Square Legendre-Chebychev quadratures establishing superiority of the latter. We establish the high quality of DORT's solution to this benchmark exercise by demonstrating that the multiplication factor asymptotically approaches the reference solution as stated in our self-imposed success criterion. High accuracy of the pin power distribution is also attained, however: convergence to the reference values is not realized. We conjecture that this is due to the lack of error information in the reference values. Our results also illustrate DORT's high accuracy on reasonable meshes and quadrature orders, as well as the sufficiency of a crude, square, geometric approximation of the rod-moderator interface to achieve high accuracy.

BOT3P is a set of standard FORTRAN 77 language programs developed at the ENEA-Bologna Nuclear Data Centre. BOT3P Version 1.0 was originally conceived 10 give the users of the DORT and TORT deterministic transport codes some useful diagnostic tools to prepare and to check their input data files. BOT3P Version 3.0 contains some important additions in the input geometrical model description, such as rod and hexagonal geometrical objects, respecting the exact cross-sectional area value and very suitable to describe a reactor lattice in detail. Moreover, it has extended the possibility to produce the geometrical, material distribution, and fixed neutron source data far the deterministic transport codes TWODANT and THREEDANT of the DANTSYS system and far the PARTISN code too, starting from the same input to BOT3P. When users require X-Y-Z TORT/THREEDANT/PARTISN mesh grids to be generated, BOT3P Version 3.0 produces a geometrical input far the MCNP Monte Carlo transport code also, where the MCNP cells correspond to the X-Y-Z bodies created for TORT.BOT3P Version 3.0 lets users specify areas/volumes of the model where the zone/material distribution can be defined not only by a combinatorial geometry but also by an external source, such as one originated from computerized tomography scan data (only for three-dimensional applications) and from one or more external DORT/TORT input files. BOT3P was developed on a DIGITAL UNIX ALPHA 500/333 workstation and successfully used in some complex neutron shielding and criticality benchmarks. It was also tested on Red Hat Linux 7.1 and is designed to run on most UNIX platforms. All BOT3P versions are publicly available from the Organisation for Economic Co-operation and Development/ Nuclear Energy Agency Data Bank (NEA-1627, NEA-1678).

Lewis' MOX Benchmark, C5G7MOx, was designed to test the performance of deterministic transport methods and codes in solving reactor physics problems without resorting to homogenization techniques. The exercise comprised a two- and a three-dimensional configuration. The two-dimensional case has been completed and a comprehensive comparison of the results has been reported. In this paper we report our team' s contribution 10 the original version of the three-dimensional benchmark problem, which since has been revised to involve stronger 3D effects. Solution of the latter version is currently underway.Similar to our approach to solving the two dimensional benchmark with DORT, our goal is not simply to produce TORT solutions to the three-dimensional problem that are close to the Monte Carlo reference solution. Rather, we solve the problem on a sequence of refined spatial grids using increasing order angular quadratures and observe the convergence of the eigenvalue with model refinement.

In many practical radiation transport applications today the cost for solving refined, large size and complex three-dimensional (3D) problems is not so much computing but is linked to the effort required by an expert to prepare the model, verify and validate that it is correct and represents to a specified tolerance the real design or facility. This becomes particularly cumbersome for detailed reactor core or shield descriptions. The need for developing tools that facilitate the task to the physicist or engineer, by reducing the lime required, by facilitating through effective graphical display the verification of correctness, and finally that help the interpretation of the results obtained has clearly emerged, in particular, for 3D general purpose radiation transport codes. Such tools will facilitate computations requiring a very large number of meshes and high performance computers.The present paper shows the results of efforts in this field. In particular, the reliability of the BOT3P pre-post-processor system of programs, originally developed at the Nuclear Data Centre in ENEA Bologna and dedicated to the DORT (2D) and TORT (3D) discrete ordinates transport codes, was tested in the context of a 3D analysis of the VENUS-3 (SCK/CEN-Mol, Belgium) neutron shielding benchmark experiment performed with the TORT code.

BOT3P consists of a set of standard FORTRAN 77 language programs that gives the users of the deterministic transport codes DORT and TORT some useful diagnostic tools to prepare and check the geometry of their input data files far both Cartesian and cylindrical geometries including graphical display modules. BOT3P produces at the same time the geometrical and material distribution data far the deterministic transport codes TWODANT and THREEDANT and, only in three-dimensional (3D) Cartesian geometry, far the Monte Carlo Transport Code MCNP. This makes it possible to compare directly for the same geometry the effects stemming from the use of different data libraries and solution approaches on transport analysis results. Through the use of BOT3P, radiation transport problems with complex 3D geometrical structures can be modelled easily, as a relatively small amount of engineer-time is required and refinement is achieved by changing few parameters. This tool is useful far solving very large challenging problems.

In questo lavoro viene presentato un modello dinamico di disequilibrio per l'analisi del mercato del lavoro nell'industria manifatturiera italiana. La specificazione proposta considera come variabili esplicative il razionamento proveniente dai periodi precedenti ed allo stesso tempo permette velocità di aggiustamento dei salari, al rialzo e al ribasso, tra loro diverse. Vengono presentate e discusse le proprietà statistiche del modello completo; l'inferenza si basa sul modello condizionale ai regimi per il quale si considerano sia la parametrizzazione in forma ridotta che quella in forma recursiva, al fine di verificare le restrizioni di sovraidentificazione. I risultati dell'analisi empirica permettono di constatare differenze strutturali significative tra il mercato del lavoro maschile e quello femminile, soprattutto per ciò che riguarda gli effetti di salario e quelli del reddito da non lavoro, così come le velocità di aggiustamento dei salari., Statistica; Vol 46, No 3 (1986)

Within the framework of the activities proposed by the OECD/NEA Nuclear Science Committee Task Force on Computing Radiation Dose and Modelling of Radiation-Induced Degradation of Reactor Components (TFRDD), the results of a three-dimensional deterministic transport analysis of the VENUS-3 neutron shielding benchmark experiment are presented. The work was performed at the ENEA-Bologna Nuclear Data Centre. In particular the discrete ordinates transport code TORT-3.2 was used together with the ENDF/B-VI based DLC-185/BUGLE-96 cross section library and the IRDF-90 Version 2 dosimetry file. Among the available low-flux experiments, the VENUS-3 experiment offers the exceptional advantage of exhibiting a realistic radial core shape and a neutron spectrum typical of PWRs together with a L3P (Low Leakage Loading Pattern) core region. These features permit, in particular, an interesting test of the calculational methods and cross section libraries addressed to predict the fast neutron damage parameters in the PWR pressure vessels.

A new pointwise library for nuclear fission applications, named MCJEF22NEA.BOLIB, was produced at the Nuclear Data Centre of ENEA-Bologna. The general features of the library, processed in ACE format for the MCNP Monte Carlo transport code with the NJOY-94.66 nuclear data processing system, are described. The library is based on the JEF-2.2 evaluated data file and contains at present 107 isotopes/natural elements, including fission products, processed for up to eight temperatures. The present library was satisfactorily tested in thermal and fast criticality benchmarks. For analyses below 20 MeV, MCJEF22NEA.BOLIB was applied also in cell and core calculations dedicated to the study of the subcritical accelerator driven systems (ADS).

BOT3P (Bologna Transport Analysis Pre-Post-Processors) is a set of standard FORTRAN 77 language programs which were developed at the ENEA-Bologna Nuclear Data Centre. These programs aim at giving the users of the DORTand TORT deterministic transport codes, incIuded in the DOORS-3 2 software package, some useful diagnostic tools to prepare and to check their input data files. The programs were compiled on a DIGITAL UNIX ALPHA 500 workstation and successfully used in some complex applications such as in shielding benchmarks.

A new pointwise library for nuclear fission applications, named MCJEF22.BOLIB, was produced at the Nuclear Data Centre of ENEA-Bologna. The general features of this neutron cross section library below 20 MeV, processed in ACE format for the MCNP Monte Carlo transport code with the NJOY-94.66 nuclear data processing system, are described. The library is based on the JEF-2.2 evaluated data files and contains at the moment 98 isotopes/natural elements including fission products, processed up to eight temperatures: 300 °K, 500 °K, 560 °K, 760 °K, 800 °K, 1000 °K, 1500 °K and 2200 °K. The processed data include gamma-production data when the basic JEF-2.2 evaluated data files contain these kind of data. The present library was satisfactorily tested in thermal and fast criticality benchmarks. For analyses below 20 MeV, MCJEF22.BOLIB can be applied also in cell and core calculations dedicated to the study of the subcritical accelerator driven systems (ADS).

A new version (April 1999) of the MCB6.BOLIB library for nuclear fission applications, produced at the Nuclear Data Centre of ENEA-Bologna, is presented. The general features of this pointwise neutron cross section library below 20 MeV, processed in ACE format for the MCNP Monte Carlo transport code with the NJOY-94.66 nuclear data processing system, are described. The library is based on the ENDF/B-VI Release 3 evaluated data files and contains at the moment 96 isotopes/natural elements including fission products, processed up to eight temperatures: 300 °K, 500 °K, 560 °K, 760 °K, 800 °K, 1000 °K, 1500 °K and 2200 °K. The processed data include gamma-production data when the basic ENDF/B-VI Release 3 evaluated data files contain these kind of data. The present library was satisfactorily tested in thermal and fast criticality benchmarks. For analyses below 20 MeV, MCB6.BOLIB can be applied also in cell and core calculations dedicated to the study of the subcritical accelerator driven systems (ADS).

Within the framework of the activities of the OECD NEA-NSC Task Force on Computing Radiation Dose and Modelling of Radiation-induced Degradation of Reactor Components (TFRDD), it was proposed to perform neutron shielding calculations for the VENUS-1 benchmark experiment (PWR core, fresh fuel loading), arranged in the SCK/CEN Centre of Mol (Belgium). The purpose of this international blind test, i.e. without knowing in advance the experimental dosimetry data, was to prove that the calculated dose predictions can be made within 20% of uncertainty with respect to the experimental data. The goal of the complex of these activities was to improve the calculational accuracy of the neutron damage parameters used in the LWR pressure vessel dosimetry. The exclusive use of two-dimensional transport codes was recommended for the VENUS-1 analysis. The final results of three fixed source calculations (two in plane and one in polar geometry) of the VENUS- 1 experiment, performed with the DORT-3.1 two-dimensional discrete ordinates transport code (included in the DOORS-3.1 ORNL modular system of deterministic codes), are presented with a synthetic description of the calculational features.