Studies in 3-oxy-assisted 3-aza Cope rearrangements

On thermolysis appropriately substituted N-silyloxy-N-allyl enamines undergo smooth 3,3-sigmatropic rearrangments to the corresponding N-silyloxy imino ethers.

Rearranjos 3-aza-cope de N-alil-N-sililoxi enaminas

O rearranjo [3,3]-sigmatr��pico t��rmico (180��C) de diferentes N-alil-N-sililoxi enaminas foi estudado. Os respectivos produtos de rearranjo (��teres de ��xima) foram obtidos com rendimentos elevados (80%). A regiosselectividade, [3,3] vs [1,3], e a diastereosselectividade do processo foram elevadas, superior a 99% e aproximadamente 80%, respectivamente. Foi demonstrada a import��ncia do grupo sililoxilo na promo����o do rearranjo face a substratos sem este tipo de substitui����o. Posteriormente, foi estudada a possibilidade de acelera����o ani��nica deste tipo de rearranjo por forma����o de oxiani��o ligado ao ��tomo de azoto. A estrat��gia seguida para a forma����o do mesmo, consistiu na O-dessilila����o de diferentes N-alil-N-sililoxi enaminas tendo-se obtido as nitronas correspondentes ou produtos de cicliza����o. Num exemplo envolvendo um derivado de isoxazole-5-(2H)-ona foi observado um aumento de velocidade do rearranjo por reac����o com i��o etoxilo. Este aumento de velocidade foi atribu��do �� abertura de anel do N-O ��ster c��clico para o N-oxiani��o, seguida de rearranjo e posterior fecho. M��todos alternativos de acelera����o do rearranjo por gera����o de carga positiva, parcial ou completa, no ��tomo de azoto levaram apenas �� dessilila����o das N-alil-N-sililoxi enaminas. ABSTRACT - [3,3]-sigmatropic rearrangement of a variety of N-allyl-N-silyloxy enamines was studied. The corresponding rearrangement products (oxime-ethers) were obtained in high yields (80%). High regioselectivity, [3,3] vs [1,3] (> 99%) and in appropriate cases, diastereoselectivity (80%) were observed. The importance of the silyloxy group in promoting the rearrangement, in relation to substrates lacking this functionality, is underlined. The possible anionic acceleration of the rearrangements was next examined by O-desilylation the N-silyloxy group bonded to the nitrogen. Attempted generation of these species however, was found to lead either to the corresponding nitrones or to cyclization products. In one particular example involving an isoxazol-5-(2H)-one derivative rate enhancement of rearrangement was indeed observed with ethoxide ion. It is tentatively attributed to ring opening of the cyclic N-O ester to the N-oxyanion ethyl ester followed by rearrangement and subsequent reclosure. Alternative methods to accelerate the process by generating a partial or complete positive charge on the nitrogen atom led only to desilylation.

Happiness, hope and affection as predictors of quality of life and functionality of individuals with heart failure at 3 month follow up

Introduction: Meeting the actual role of positive psychology, begins to be recognized the contribution of positive variables in health outcomes. Objective: To know the contribution of happiness, hope and affection individually and as a whole in the quality of life and functionality of individuals with heart failure. Population and Methodology: 128 individuals with heart failure, 98 men and 30 women, 61.9��12,1 years of age, 6,6��3,9 years of school and 74,2% retired because of this disease. 56,3% were in Class III of New York Heart Association, with poor left ventricular ejection fraction (25,3��6,2%). The clinical history was of 9,4��8,5 years for this heart disease and had at least one hospitalization due to heart failure with 51,6% having ischemic heart disease.

Fungi, bacteria and pollens seasonally quantified at 3 basic schools in Lisbon: evaluation of ventilation need

Nowadays, most individuals spend about 80% of their time indoor and, consequently, the exposure to the indoor environment becomes more relevant than to the outdoor one. Children spend most of their time at home and at school and evaluations of their indoor environment are important for the time-weighted exposure. Due to their airways still in development, children are a sensitive group with higher risk than adults. Larger impact in health and educational performance of children demand indoor air quality studies of schools. The aim of this study was to assess the children exposure to bioaerosols. A methodology based upon passive sampling was applied to evaluate fungi, bacteria and pollens; its procedures and applicability was optimized. An indoor air study by passive sampling represents an easier and cheaper method when comparing with the use of automatic active samplers. Furthermore, it is possible to achieve important quality information without interfering in the classroom activities. The study was conducted in three schools, representative of different environments in the Lisbon urban area, at three different periods of the year to obtain a seasonal variation, to estimate the variability through the city and to understand the underneath causes. Fungi and bacteria were collected indoor and outdoor of the classrooms to determine the indoor/outdoor ratios and to assess the level of outdoor contamination upon the indoor environment. The children's exposure to pollen grains inside the classrooms was also assessed.

Orienta����o vocacional de jovens surdos no 3�� ciclo

O presente estudo, de natureza qualitativa, visou explorar a forma como a orienta����o vocacional dos alunos surdos no 3�� CEB estava a ser levada a cabo nas escolas de refer��ncia para o ensino bilingue, da ��rea de Lisboa. Utiliz��mos entrevistas semi-directivas, de forma a conhecer a percep����o dos profissionais sobre o processo de orienta����o referido anteriormente. Posteriormente entrevist��mos os alunos do ensino secund��rio que j�� passaram ou est��o a passar pelo processo de escolha vocacional. Foram entrevistados 8 profissionais (4 professores e 4 psic��logos) e 6 alunos. No presente estudo, a partir do cruzamento dos resultados das entrevistas foi poss��vel obter a percep����o dos dois grupos sobre o tema em estudo e compar��-las. Assim, pudemos concluir que os profissionais identificam as suas necessidades de forma����o na ��rea da LGP e sobre o trabalho com esta popula����o. Consideram a orienta����o importante, mas necessitando de mais investimento por parte de uma equipa pluridisciplinar, devendo ser iniciada o mais precocemente poss��vel. Identificam a barreira da comunica����o como o principal entrave dos alunos no acesso �� informa����o, da�� a necessidade de diferenciar a orienta����o vocacional da dos ouvintes, para fazer frente a uma oferta formativa das escolas de refer��ncia escassa e com apoios limitados. Em suma, defendem a implementa����o de um programa de orienta����o vocacional sistem��tico e mais prolongado no tempo que v�� ao encontro das necessidades deste grupo espec��fico de alunos. Os alunos entrevistados, por sua vez, corroboram, na maioria das vezes, as afirma����es dos profissionais sendo mais directos nas suas afirma����es. Assim, consideram que a orienta����o vocacional �� ineficiente, com lacunas formativas na ��rea das profiss��es, sendo o apoio escasso e iniciado tardiamente, sem individualiza����o e/ou diferencia����o em rela����o aos alunos ouvintes. Acresce a insatisfa����o com a escolha, devido, em grande parte, ��s barreiras relativas ao sucesso em alguns cursos do secund��rio, e no acesso a algumas profiss��es que p��em em causa a realiza����o do sonho profissional, referido pela maioria dos alunos entrevistados.

Enthalpies of Solution of 1-Butyl-3-methylimidazolium Tetrafluoroborate in 15 Solvents at 298.15 K

Enthalpies of solution of 1-butyl-3-methylimidazolium tetra fluoroborate, [BMIm]BF4, are reported at 298.15 K in a set of 15 hydrogen bond donor and hydrogen bond acceptor solvents, chosen by their diversity, namely, water, methanol, ethanol, 1,2-ethanediol, 2-choroethanol, 2-methoxyethanol, formamide, propylene carbonate, nitromethane, acetonitrile, dimethyl sulfoxide, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, and aniline. These values are shown to be largely independent of [BMIm]BF4 concentration. The obtained enthalpies of solution vary from very endothermic to quite exothermic, thus showing a very high sensitivity of the enthalpies of solution of [BMIm]BF4 to solvent properties. Solvent effects on the solution process of this IL are analyzed by a quantitative structure-property relationship methodology, using the TAKA equation and a modified equation, which significantly improves the model's predictive ability. The observed differences in the enthalpies of solution are rationalized in terms of the solvent properties found to be relevant, that is, pi* and E-T(N).

Multi-stage evolution of a sub-aerial volcanic ridge over the last 1.3 Myr: S. Jorge Island, Azores Triple Junction

New K/Ar dating and geochemical analyses have been carried out on the WNW-ESE elongated oceanic island of S. Jorge to reconstruct the volcanic evolution of a linear ridge developed close to the Azores triple junction. We show that S. Jorge sub-aerial construction encompasses the last 1.3 Myr, a time interval far much longer than previously reported. The early development of the ridge involved a sub-aerial building phase exposed in the southeast end of the island and now constrained between 1.32 +/- 0.02 and 1.21 +/- 0.02 Ma. Basic lavas from this older stage are alkaline and enriched in incompatible elements, reflecting partial melting of an enriched mantle source. At least three differentiation cycles from alkaline basalts to mugearites are documented within this stage. The successive episodes of magma rising, storage and evolution suggest an intermittent reopening of the magma feeding system, possibly due to recurrent tensional or trans-tensional tectonic events. Present data show a gap in sub-aerial volcanism before a second main ongoing building phase starting at about 750 ka. Sub-aerial construction of the S. Jorge ridge migrated progressively towards the west, but involved several overlapping volcanic episodes constrained along the main WNW-ESE structural axis of the island. Malic magmas erupted during the second phase have been also generated by partial melting of an enriched mantle source. Trace element data suggest, however, variable and lower degrees of partial melting of a shallower mantle domain, which is interpreted as an increasing control of lithospheric deformation on the genesis and extraction of primitive melts during the last 750 kyr. The multi-stage development of the S. Jorge volcanic ridge over the last 1.3 Myr has most likely been greatly influenced by regional tectonics, controlled by deformation along the diffuse boundary between the Nubian and the Eurasian plates, and the increasing effect of sea-floor spreading at the Mid-Atlantic Ridge.

A 3-phase model for VIS/NIR mu C-Si : H p-i-n detectors

The spectral response and the photocurrent delivered by entirely microcrystalline p-i-n-Si:H detectors an analysed under different applied bias and light illumination conditions. The spectral response and the internal collection depend not only on the energy range but also on the illumination side. Under [p]- and [n]-side irradiation, the internal collection characteristics have an atypical shape. It is high for applied bias and lower than the open circuit voltage, shows a steep decrease near the open circuit voltage (higher under [n]-side illumination) and levels off for higher voltages. Additionally, the numerical modeling of the VIS/NIR detector, based on the band discontinuities near the grain boundaries and interfaces, complements the study and gives insight into the internal physical process.

N.C.R.F. 3: adop����o pela primeira vez das Normas Contabil��sticas e de Relato Financeiro

Disserta����o para obten����o do Grau de Mestre em Auditoria

Palaeomagnetic study of a subaerial volcanic ridge (Sao Jorge Island, Azores) for the past 1.3 Myr: evidence for the Cobb Mountain Subchron, volcano flank instability and tectonomagmatic implications

We present a palaeomagnetic study on 38 lava flows and 20 dykes encompassing the past 1.3 Myr on S. Jorge Island (Azores ArchipelagoNorth Atlantic Ocean). The sections sampled in the southeastern and central/western parts of the island record reversed and normal polarities, respectively. They indicate a mean palaeomagnetic pole (81.3 degrees N, 160.7 degrees E, K= 33 and A95= 3.4 degrees) with a latitude shallower than that expected from Geocentric Axial Dipole assumption, suggesting an effect of non-dipolar components of the Earth magnetic field. Virtual Geomagnetic Poles of eight flows and two dykes closely follow the contemporaneous records of the Cobb Mountain Subchron (ODP/DSDP programs) and constrain the age transition from reversed to normal polarity at ca. 1.207 +/- 0.017 Ma. Volcano flank instabilities, probably related to dyke emplacement along an NNWSSE direction, led to southwestward tilting of the lava pile towards the sea. Two spatially and temporally distinct dyke systems have been recognized on the island. The eastern is dominated by NNWSSE trending dykes emplaced before the end of the Matuyama Chron, whereas in the central/western parts the eruptive fissures oriented WNWESE controlled the westward growth of the S. Jorge Island during the Brunhes Chron. Both directions are consistent with the present-day regional stress conditions deduced from plate kinematics and tectonomorphology and suggest the emplacement of dykes along pre-existing fractures. The distinct timing and location of each dyke system likely results from a slight shift of the magmatic source.

Classe 3: invent��rios e activos biol��gicos

Estrutura da obra: ��ndice de quadros - Lista de abreviaturas - Apresenta����o - Introdu����o - Classe 3 ��� invent��rios e activos biol��gicos - Normas relevantes - Reconhecimento - Compara����o SNC vs. Poc - Detalhe das contas; Contratos de constru����o - Auditoria aos invent��rios e activos biol��gicos -Conclus��o

Analisador de espectro de baixo custo com frequ��ncia de opera����o entre 2 e 3 GHz

Com o surgimento de novos sistemas de telecomunica����es sem fios, que necessitam de maiores pot��ncias de emiss��o e largura de banda dispon��vel, surgem os regulamentos que controlam as emiss��es r��dio. S�� assim estas tecnologias podem coexistir em bandas pr��ximas, com o m��ximo desempenho e com a garantia que os n��veis de polui����o electromagn��tica n��o s��o ultrapassados. Cada vez mais, regulamentos que limitam a pot��ncia da transmiss��o t��m em vista quest��es de sa��de p��blica e por isso devem ser estritamente respeitados. Para se poder controlar as emiss��es r��dio �� necess��rio um dispositivo que consiga analisar o espectro r��dio. Um dos instrumentos fundamentais na metrologia de radiofrequ��ncia �� o analisador de espectros, que tem como principal fun����o apresentar a pot��ncia de por����es do espectro em fun����o da frequ��ncia. Existem v��rios tipos de analisadores espectrais, que se baseiam em arquitecturas de recep����o distintas. O tipo de analisador define a sua complexidade e o tipo de an��lises que consegue fazer. Com esta disserta����o pretende-se mostrar a implementa����o de um analisador de espectro port��til, de baixo custo, baseado num receptor heter��dino e com uma frequ��ncia de opera����o compreendida entre os 2 e os 3 GHz. Este projecto abrange diversas ��reas, desde o hardware de recep����o r��dio, passando pelo microcontrolador que faz a aquisi����o de dados e comunica����o com o computador, acabando na aplica����o que foi desenvolvida em Java para permitir ao utilizador uma interface de utiliza����o simples e funcional. Foi tamb��m desenvolvida com sucesso uma antena impressa adequada �� banda de frequ��ncia referida. Embora tenham existidos problemas simples, um na localiza����o do filtro passa-banda e o outro na resposta do filtro interm��dio, os objectivos foram alcan��ados obtendo-se um analisador de espectro port��til, funcional e de baixo custo, conforme pretendido. O analisador tem um erro m��ximo na detec����o de pot��ncia de 2,5 dB e o tempo de varrimento m��ximo �� cerca de 16 segundos com 500 pontos de resolu����o. Foram realizadas v��rias medi����es e uma compara����o com um analisador de espectros comercial, para demonstrar o funcionamento e desempenho do analisador desenvolvido, tendo os resultados sido bastante promissores. A funcionalidade deste analisador medir a pot��ncia do sinal ao longo do tempo �� uma mais-valia face ao analisador comercial utilizado para a compara����o.

O Contributo do sistema SAP R/3 no controlo interno na REFER

Disserta����o apresentada ao Instituto Superior de Contabilidade para a obten����o do Grau de Mestre em Auditoria Orientador: Mestre Agostinho Sousa Pinto

Complexes of copper(II) with 3-(ortho-substituted phenylhydrazo)pentane-2,4-diones: syntheses,properties and catalytic activity for cyclohexane oxidation

Reactions of copper(II) with 3-phenylhydrazopentane-2,4-diones X-2-C6H4-NHN = C{C(= O)CH3}(2) bearing a substituent in the ortho-position [X = OH (H2L1) 1, AsO3H2 (H3L2) 2, Cl (HL3) 3, SO3H (H2L4) 4, COOCH3 (HL5) 5, COOH (H2L6) 6, NO2 (HL7) 7 or H (HL8) 8] lead to a variety of complexes including the monomeric [CuL4(H2O)(2)]center dot H2O 10, [CuL4(H2O)(2)] 11 and [Cu(HL4)(2)(H2O)(4)] 12, the dimeric [Cu-2(H2O)(2)(mu-HL2)(2)] 9 and the polymeric [Cu(mu-L-6)](n)] 13 ones, often bearing two fused six-membered metallacycles. Complexes 10-12 can interconvert, depending on pH and temperature, whereas the Cu(II) reactions with 4 in the presence of cyanoguanidine or imidazole (im) afford the monomeric compound [Cu(H2O)(4){NCNC(NH2)(2)}(2)](HL4)(2)center dot 6H(2)O 14 and the heteroligand polymer [Cu(mu-L-4)(im)](n) 15, respectively. The compounds were characterized by single crystal X-ray diffraction (complexes), electrochemical and thermogravimetric studies, as well as elemental analysis, IR, H-1 and C-13 NMR spectroscopies (diones) and ESI-MS. The effects of the substituents in 1-8 on the HOMO-LUMO gap and the relative stability of the model compounds [Cu(OH)(L-8)(H2O)]center dot H2O, [Cu(L-1)(H2O)(2)]center dot H2O and [Cu(L-4)(H2O)(2)]center dot H2O are discussed on the basis of DFT calculations that show the stabilization follows the order: two fused 6-membered > two fused 6-membered/5-membered > one 6-membered metallacycles. Complexes 9, 10, 12 and 13 act as catalyst precursors for the peroxidative oxidation (with H2O2) of cyclohexane to cyclohexanol and cyclohexanone, in MeCN/H2O (total yields of ca. 20% with TONs up to 566), under mild conditions.

O desenvolvimento do conceito de ��rea: um estudo com alunos do 3.�� ano de escolaridade

O objetivo desta investiga����o �� compreender como �� que alunos do 3.�� ano de escolaridade desenvolvem o conceito de ��rea com ��nfase em conhecimentos sobre figuras e propriedades geom��tricas. Para melhor objetivar o estudo, formulei tr��s quest��es que orientaram a investiga����o. Pretendo (1) compreender como �� que os alunos mobilizam conhecimentos sobre as propriedades das figuras geom��tricas no estudo da ��rea de uma figura plana? A que estrat��gias recorrem? Que dificuldades sentem? (2) que compreens��o �� que os alunos t��m sobre o processo de medi����o? e (3) que ideias e/ou experi��ncias s��o relevantes no desenvolvimento do conceito de ��rea? Este �� um estudo que se insere no paradigma interpretativo e que segue uma abordagem qualitativa, pelo que n��o visa generaliza����o de resultados, mas uma descri����o compreensiva dos processos vivenciados, tendo em conta os contextos pessoais e sociais. Optei por realizar dois Estudos de Caso. Os dados foram recolhidos atrav��s de fontes diversificadas, donde se destacam a observa����o participante e a an��lise de registos audiovisuais e escritos dos alunos. A an��lise dos dados teve por refer��ncia categorias criadas com base em contributos da literatura de refer��ncia. As conclus��es desta investiga����o centram-se numa an��lise acerca das estrat��gias a que os alunos em estudo tendencialmente mais recorrem, visando tamb��m algumas das suas dificuldades mais relevantes e sobre as quais importa refletir. Destaca-se que ambos os alunos foram capazes de recorrer a racioc��nios baseados e n��o baseados na medida, embora seja evidente uma tend��ncia para racioc��nios baseados na medida. �� igualmente importante referir que os dois alunos revelaram um bom conhecimento acerca do processo de medi����o, mesmo quando ele implicava a defini����o de uma unidade de medida adequada e/ou mudan��a de unidade. �� dado, tamb��m, destaque ��s experi��ncias matem��ticas que devem ser proporcionadas aos alunos no sentido do desenvolvimento de um conhecimento amplo e flex��vel do conceito de ��rea. - Abstract The purpose of this investigation is to understand the development of 3rd year students��� concept of area based on their knowledge of geometrical properties and figures. As means to orientate the present study, the following investigation questions were formulated: 1) how do students use their knowledge about geometrical properties in order to understand geometrical shape���s areas? Which strategies do they use? What do they struggle with? (2) What is their understanding about measurement? And (3) what are the most relevant mathematical reasonings and classroom tasks in the development of the concept of area? This is a study that follows a qualitative approach: it does not intend to be a generalization, but a fully comprehensive description of the witnessed learning processes, bearing in mind the social and personal contexts. As such, two study-cases were developed. The data were collected through various sources, such as direct observation and analysis of audiovisual records or written worksheets. The scrutiny of the generated data was undertaken following criteria based on the literature of reference. The conclusions of this investigation are centered on the most used strategies as well as the students��� difficulties upon which it is important to discuss. It was noticed that the two students were able to use both measurement and non measurement thinking ��� although, preferably, they tend to use the first one. On the other hand, it is equally demonstrated that the two students have shown good acquaintance about measurement, even if obliged to the establishment of a suitable unit of measurement and/or change of units. At last, it is also referred which mathematical classroom tasks are important to develop a sustained and comprehensive concept of area.