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.

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonateand 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)-(PPh3)] (2), [Ag(Tpms)(PCy3)] (3), [Ag(PTA)][BF4] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh3 = triphenylphosphane, PCy3 = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane) have been synthesized and fully characterized by elemental analyses, H-1, C-13, and P-31 NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N-3-facially coordinating mode, while in 2 and 5 a N2O-coordination is found, with the SO3 group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains Enterococcus faecalis (ATCC 29922), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Streptococcus pyogenes (SF37), Streptococcus sanguinis (SK36), Streptococcus mutans (UA1S9), Escherichia coli (ATCC 25922), and the fungus Candida albicans (ATCC 24443). Complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA EB system on addition of Ag complexes shows that the fluorescence quenching of DNA EB complex occurs and compound 3 is particularly active. Complexes 1-5 exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO3, which has been used as a control, following the same order of activity inhibition on DNA, i.e., 3 > 2 > 1 > 5 > AgNO3 >> 4.

Trends in properties of para-substituted 3-(phenylhydrazo)pentane-2,4-diones

Trends between the Hammett's sigma(p) and related normal sigma(n)(p), inductive sigma(I), resonance sigma(R), negative sigma(-)(p) and positive sigma(+)(p) polar conjugation and Taft's sigma(o)(p) substituent constants and the N-H center dot center dot center dot O distance, delta(N-H) NMR chemical shift, oxidation potential (E-p/2(ox), measured in this study by cyclic voltammetry (CV)) and thermodynamic parameters (pK, Delta G(0), Delta H-0 and Delta S-0) of the dissociation process of unsubstituted 3-(phenylhydrazo)pentane-2,4-dione (HL1) and its para-substituted chloro (HL2), carboxy (HL3), fluoro (HL4) and nitro (HL5) derivatives were recognized. The best fits were found for sigma(p) and/or sigma(-)(p) in the cases of d(N center dot center dot center dot O), delta(N-H) and E-p/2(ox), showing the importance of resonance and conjugation effects in such properties, whereas for the above thermodynamic properties the inductive effects (sigma(I)) are dominant. HL2 exists in the hydrazo form in DMSO solution and in the solid state and contains an intramolecular H-bond with the N center dot center dot center dot O distance of 2.588(3)angstrom. It was also established that the dissociation process of HL1-5 is non-spontaneous, endothermic and entropically unfavourable, and that the increase in the inductive effect (sigma(I)) of para-substitutents (-H < -Cl < -COOH < -F < -NO2) leads to the corresponding growth of the N center dot center dot center dot O distance and decrease of the pK and of the changes of Gibbs free energy, of enthalpy and of entropy for the HL1-5 acid dissociation process. The electrochemical behaviour of HL1-5 was interpreted using theoretical calculations at the DFT/HF hybrid level, namely in terms of HOMO and LUMO compositions, and of reactivities induced by anodic and cathodic electron-transfers. Copyright (C) 2010 John Wiley & Sons, Ltd.

Preval��ncia de dor lombar n��o espec��fica em alunos da Escola E.B. 2/3 de Santa Marinha

A dor lombar �� um dos dist��rbios m��sculo-esquel��ticos mais comuns, verificando-se um aumento na ��ltima d��cada em crian��as. O objectivo deste estudo foi determinar a preval��ncia de dor lombar n��o espec��fica no ��ltimo m��s e no ��ltimo ano em crian��as em idade escolar. O estudo foi do tipo observacional descritivo transversal, a amostra foi constitu��da por 219 alunos entre os 10 e os 16 anos. Os instrumentos usados foram um question��rio para a dor lombar, fita m��trica e balan��a. Concluiu-se que preval��ncia de dor lombar na popula����o estudada �� elevada. Verificamos associa����o entre a dor lombar e o sexo feminino.

Analysis of the interference of endogenous circadian rhythms on 3'- deoxy- 3'- [18F]Fluorothymidine physiological uptake at the human bone marrow

The main purpose of the present study is to determine if the circadian rhythms present in the human bone marrow are likely to influence 3���- deoxy- 3���-[18F] Fluorothymidine (18F-FLT) uptake in the same organ. The 18F-FLT is a Thymidine analogous proliferation agent. The relatively high physiological uptake of this tracer in the bone marrow diminishes the Tumor/Background (T/B) ratio, decreasing the detection accuracy of PET/CT and possibly affecting SUV quantifications.

A Novel Short-Step Synthesis of New Xanthenedione Derivatives from the Cyclization of 3-Cinnamoyl-2-styrylchromones

Novel (E)-3-aryl-4-benzylidene-8-hydroxy-3,4-dihydro-1 H-xanthene-1,9(2H)-diones are prepared by the cyclization of (E,E)-3-cinnamoyl-5-hydroxy-2-styrylchromones efficiently catalyzed with boron tribromide. The (E,E)-3-cinnamoyl-5-hydroxy-2-styrylchromones are obtained from the Baker���Venkataraman rearrangement of (E,E)-2-acetyl-1,3-phenylene bis(3-phenylacrylate), which is greatly improved under microwave irradiation.

A new strategy for the synthesis of 3-cinnamoyl-2-styrylchromones and their transformation into new xanthenodiones derivatives

23rd ISHC Congress will be held in Glasgow, Scotland from July 31 August 4, 2011.

Synthesis, structure and electrochemical behaviour of Na, Mg-II, Mn-II, Cd-II and Ni-II complexes of 3-(2-carboxyphenylhydrazone)pentane-2,4-dione

Mononuclear manganese(II) [Mn(kappa O-HL)(2)(CH3OH)(4)] (4), nickel(II) [Ni(kappa O-2, kappa N-L)(H2O)(3)] (5), cadmium(II) [Cd(kappa O-2-HL)(2)(CH3OH)(3)] (7), tetranuclear zinc(II) [Zn-4(mu-OH)(2)(1 kappa O:2 kappa O-HL)(4)(kappa O-HL)(2)(H2O)(4)] (6) and polynuclear aqua sodium(I) [Na(H2O)(2)(mu-H2O)(2)](n)(HL)(n) (2) and magnesium(II) [Mg(OH)(H2O)(mu-H2O)(2)](n)(-HL)(n) (3) complexes were synthesized using 3-(2-carboxyphenyl-hydrazone)pentane-2,4-dione (H2L, 1) as a ligand precursor. The complexes were characterized by single crystal X-ray diffraction, elemental analysis, IR, H-1 and C-13 NMR (for 2, 3, 6 and 7) spectroscopies. Mono- or dianionic deprotonated derivatives of H2L display different coordination modes and lead to topologies and nuclearities of the complexes depending on metal ions and conditions used for the syntheses. Extensive intermolecular H-bonds form supramolecular arrangements in 1D chains (4 and 6), 1D chains of the organic anion and 2D networks of the metal-aqua aggregates (2 and 3), 2D networks (7) or even 3D frameworks (5). Electrochemical studies, by cyclic voltammetry and controlled potential electrolysis, show ligand centred redox processes as corroborated by theoretical DFT calculations in terms of LUMO and HOMO compositions. (C) 2012 Elsevier Ltd. All rights reserved.