Espacialidades e temporalidades da cibercultura II: Pós-Panoptismos

Sociologia das visibilidades. Panoptismo e contemporaneidade: Dispositivos inter-panópticos; Sociologia do panoptismo; Cidadão e instituições; Autores observadores do social; Ótica inter-moderna; Contra-panoptismo; Retórica do site Surveillance & Society.

Desenvolvimento de um laboratório pedagógico de vias de comunicação na Universidade do Minho

Dissertação de mestrado integrado em Engenharia Civil

Assessment of prognosis in patients with stage II colon cancer

Assessment of prognosis of patients with stage II colon cancer.

La televisione nella vita quotidiana dei bambini. II contesto come testo

(Excerto) La ricerca sociologica si colloca sempre in un hie et nunc e lo studio di cui parlen) nel mio intervento non sfugge a questa inconveniente. Come altri studi empirici sui rapporto tra giovani e media, questa lavoro e nato, innanzitutto, dagli interrogativi suscitati dai miei figli, quando erano ancora piccoli. Non posso escludere che quest' interesse sia una sorta di tentativo inconscio di placare Ia mia coscienza di fronte ai problemi che facevo fatica a risolvere ali'interno della mia famiglia. Permettetemi anche di soffermarmi brevemente sui mio paese, il Portogalla, e sulla sua realtii culturale e politica. Vorrei sottolineare che, in una prospettiva di lungo peri ado, alia maniera di Braude!, il mio ·paese ha ritrovato Ia democrazia moho recentemente, dopa mezzo secolo di oscurantismo e di repressione del pensiero e della partecipazione attiva dei cittadini alia vita sociale.

Nickel(II) complexes of bidentate N-N′ ligands containing mixed pyrazole, pyrimidine and pyridine aromatic rings as catalysts for ethylene polymerisation

This work describes the synthesis and characterisation of Ni(II) complexes of the following neutral bidentate nitrogen ligands containing pyrazole (pz), pyrimidine (pm) and pyridine (py) aromatic rings: 2-pyrazol-1-yl-pyrimidine (pzpm), 2-(4-methyl-pyrazol-1-yl)-pyrimidine (4-Mepzpm), 2-(4-bromo-pyrazol-1-yl)-pyrimidine (4-Brpzpm), 2-(3,5-dimethyl-pyrazol-1-yl)-pyrimidine (pz*pm), 2-pyrazol-1-yl-pyridine (pzpy) and bis(3,5-dimethylpyrazol-1-yl)phenylmethane (bpz*mph). The complexes [NiBr2(pzpm)] (1), [NiBr2(4-Mepzpm)] (2), [NiBr2(4-Brpzpm)] (3), [NiBr2(pz*pm)] (4), [NiBr2(pzpy)] (5) and [NiBr2(bpz*mph)] (6) were tested as catalysts for ethylene polymerisation, in the presence of the cocatalysts methylaluminoxane (MAO) or diethylaluminium chloride (AlEt2Cl), the catalyst systems 1-3/MAO showing moderate to high activities up to the temperature of 20 °C only in the presence of MAO, whereas 4-6/MAO revealed to be inactive. Other related Pd(II) complexes, already reported in previous works, such as [PdClMe(pzpm)], [PdClMe(pz*pm)], [PdClMe(pzpy)] and [PdClMe(bpz*mph)], also showed to be inactive in the polymerisation of ethylene, when activated by MAO or AlEt2Cl. Selected samples of polyethylene products were characterised by GPC/SEC, 1H and 13C NMR and DSC, showing to be low molecular weight polymers with Mn values ranging from ca. 550 to 1500 g mol−1 and unusually low dispersities of 1.2–1.7, with total branching degrees generally varying between 2 and 12%, melting temperatures from 40 to 120 °C and crystallinities from 40 to 70%.