12,536 research outputs found
Il potenziale formale della coppia Ti(IV,III) a 25°C nel mezzo HCl 1 M NaCl 2 M
No full textNell’ambito delle diverse coppie ossidoriduttive di un elemento in soluzione acquosa, vengono indicate come ipoossidate le specie appartenenti a quelle coppie il cui potenziale standard è inferiore a quello di riduzione dell’acqua ad idrogeno, e come iperossidate le specie che fanno parte di coppie con valore del potenziale di riduzione superiore a quello dell’ossigeno ad acqua. Si tratta in entrambi i casi di specie termodinamicamente poco stabili che si trasformano rispettivamente nella forma ossidata con evoluzione di idrogeno e nella forma ridotta con evoluzione di ossigeno. Tali processi sono modulati dall’attività idrogenionica della soluzione (Figura 1).
Figura 1. Intervallo di stabilità termodinamica dell’acqua
La decomposizione di queste specie da parte dell’acqua, spesso catalizzata dagli stessi elettrodi metallici delle celle utilizzate per la misura dei potenziali redox, introduce una rilevante fonte di incertezza sulla composizione delle soluzioni; a questa si aggiunge l’incertezza dovuta alla presenza di giunzioni liquide, di impurezze nei mezzi ionici, alla mancanza di controllo dei coefficienti di attività. Tutto ciò ha come effetto le rilevanti differenze riscontrabili in letteratura tra i pochi valori riportati per i potenziali redox di tali sistemi.
Alcune di queste coppie con specie ipo o iperossidate (Ag2+, Co3+ , Ce4+ , Cr2+ , V2+, U3+ , Yb2+) sono state studiate nel nostro laboratorio e, i relativi valori dei potenziali redox in cui sono coinvolte, misurati [1-7]. Funzionale in questi studi è stata la diminuzione in alcuni casi della temperatura delle soluzioni (-5°C) così da ottenere una significativa attenuazione dell’azione di decomposizione esercitata dall’acqua.
Con riferimento a quanto appena detto, si è intrapreso lo studio della coppia redox (IV,III) del titanio, che nella forma di ione titanoso, Ti3+, in particolare sotto forma di cloruro o solfato, presenta numerose applicazioni analitiche [8]. D’altra parte, per le sue proprietà di elevata resistenza, il titanio metallico trova applicazioni tecnologiche che spaziano dalle leghe speciali, ai pigmenti bianchi, alla realizzazione di protesi ortopediche. Sulla base dell’esperienza acquisita, ci siamo proposti di determinare il potenziale redox della coppia Ti(IV, III), anche perché i valori riportati in soluzione acquosa per tale grandezza risultano notevolmente differenti [9-11].
L’indagine è stata effettuata con due metodi differenti: nel primo, per ottenere la miscela dei due stati di ossidazione, si è utilizzata l’ossidazione del Ti(III) a Ti(IV) per elettrolisi controllata (titolazioni coulombometriche) seguita dalla misura in situ della fem della cella senza giunzione
+ GE | Soluzione S | Hg - GE = Elettrodo a vetro
Nel secondo metodo, la specie ipoossidata Ti(III) è stata ottenuta per riduzione del Ti(IV) con amalgama di zinco (batch) seguita da determinazione potenziometrica, analoga alla precedente. Le due metodiche indipendenti hanno fornito valori del potenziale cercato in ottimo accordo, precisamente:
Metodo coulombometrico Ef = 9 + 1 mV
Metodo batch Ef = 9 + 2 mV
Riferimenti bibliografici
1. Biedermann G, Maggio F, Romano V, Zingales R. Acta Chem. Scand. 1981; A35: 287.
2. Biedermann G, Orecchio S, Romano V, Zingales R. Acta Chem. Scand. 1986; A40:161
3. Zingales R. J. Chem. Soc. Dalton Trans 1990; 229
4. Biedermann G, Romano V. Acta Chem. Scand. 1975; A35: 615
5. Fiore M, Orecchio S, Romano V, Zingales R. J. Chem. Soc. Dalton Trans 1993; 799
6. Orecchio S, Piazzese D, Romano V, Zingales R. Ann. Chim. 1988; 88: 129
7. Amorello D, Romano V, Zingales R. Ann. Chim. 2004; 94 :113
8. Vogel A I Textbook of Quantitative Inorganic Analysis, Longmans 1961; 329
9. Kolthoff I M, Rec. Trav. Chim. Pays-Bas, 1924; 43 , 768
10. Boch R and Greiner G, Z. Anorg. Chem., 1958; 295 ,61
11. Lingane J J Anal. Chem. 1958 20 79
Do Pórtico à Urbe: a filosofia estoica e o direito romano nas Institutiones de Gaio
No full textTCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.A monografia parte da filosofia estoica antiga para, a partir dela, estabelecer possíveis referências da doutrina do Pórtico no direito romano, em especial, nas Institutiones do jurisconsulto Gaio. Por meio da pesquisa bibliográfica, da leitura de fontes e do método dedutivo de abordagem, o trabalho delineia os traços principais do estoicismo antigo e identifica as transformações dessa filosofia no mundo romano. A partir dos traços gerais do estoicismo, o trabalho segue na tentativa de demonstrar qual o papel que o direito recebe no interior de seu sistema, especialmente no estoicismo dos romanos, bem como de discutir algumas das críticas tradicionais direcionadas ao estoicismo. Por fim, a pesquisa se lança numa análise das Institutiones de Gaio, importante manual de ensino do direito romano, selecionando na fonte fragmentos, conceitos e expressões que demonstram, se não uma conexão explícita, ao menos uma compatibilidade filosófica plena com a doutrina do estoicismo.Opus ex philosophia stoica antiqua incipit; ut relationes doctrinae Porticuus apud ius Romanum, Gaii iurisconsulti in Institutione ab ea instituat. Opus insignia praecipua Stoicorum disciplinae per modum deductiuum inuestigationem ad litteram et priscarum fontium lectionem molitur et transfigurationes in mundo Romano recognoscit. Hic opus iuris finem Romanorum Stoicorum rationis ex insignia philosophiae demonstrat tanti quanti aliquae uituperationes Porticui explicat. Denique opus sibi Gaii institutionum disquisitionem tribuit; fragmina et argumenta et uocabula excipit, sin minus expressis uerbis, ut plenam conuenientiam philosophica Stoicorum disciplina demonstret.Il lavoro inizia con la filosofia stoica come punto di partenza per stabilire possibili riferimenti della dottrina Portica nel diritto romano, in particolare nelle Istitutiones del giurista Gaio. Attraverso il mezzo deduttivo, la ricerca bibliografica e la lettura di fonti primarie, il lavoro delinea le tracce principali dello stoicismo antico e identifica le trasformazioni di questa filosofia nel mondo romano. Dalle tracce dello stoicismo, il lavoro dimostra la finalità del diritto nel sistema stoico dei romani, oltre a discutere alcune delle caratteristiche tradizionali del Portico. Infine, il lavoro s’incentra sull’analisi delle Institutiones di Gaio, importante manuale di insegnamento di diritto romano, e in esso seleziona frammenti, concetti ed espressioni per dimostrare, piuttosto che una connessione esplicita, la piena compatibilità filosofica con la dottrina dello stoicismo
Aspects of the Romano-British landscape around holme on Spalding moor, east Yorkshire
No full textAn examination was undertaken of the nature and extent of Romano-British settlement and industry in the context of the landscape around Holme on Spalding Moor. An environmental reconstruction of the study area was made, showing it to be marginal, low lying and prone to wetness. The most suitable land for exploitation were the ridges of Aeolian sands. Systematic field survey over an 8 x 8 km square, together with cropmark evidence showed that site distribution was closely related to soil type, watercourses and other environmental constraints. A total of 106 Romano-British kiln and settlement sites, 49 sites with iron working or manufacture and several with evidence for glass working were discovered from fieldwalking, examination of museum collections and archives and excavations. Worked flints and stone axes showed that there had been activity on the sand ridges near to watercourses since the Neolithic. The data suggests that settlement was intensified during the later Iron Age with iron working and manufacture being undertaken especially near the dendritic creek system in which the Hasholme Iron Age log boat sank. The Romano-British pottery industry seems to have built up around the same creek system, which provided a means of distribution to Shiptonthorpe, Brough and other Romano-British settlements further afield. Fabric and form analysis of local wares when compared with pottery of known date showed that production began in the later 2nd century A.D., reaching a peak in the mid fourth.Clay was plentiful and managed woodland may have provided fuel for furnaced based industries. Settlement types showed little change from the late Iron Age, but followed developments paralleled elsewhere, with some degree of Romanisation. Marine flooding did not cause the decline of industry and settlement in the area as has been previously suggested. It is possible that these settlements formed the basis of the hamlets within the parish of Holme on Spalding Moor, although continuity has yet to be proved
Biological and physical events at T/J boundary: the carbonate factory response. A preliminary report)
No full textThis work starts from an integrated stratigraphic study
performed on a continuous and expanded section of Triassic-
Jurassic (T/J) limestones outcropping at Mt. Messapion.
The Mt. Messapion is situated at the NE part of the Thivai
(Thebes) sheet, 10 Km west of Chalkis city (Continental
Greece). The multidisciplinary investigations on this section allow to obtain a new integrated stratigraphic data helpful for the
identification of the Late Triassic-Early Jurassic events in
shallow water successions
O Institucionalismo de Santi Romano: por um diálogo entre posições críticas à modernidade jurídica
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Jurídicas, Programa de Pós-Graduação em Direito, Florianópolis, 2011Na tentativa de estabelecer um alinhavo, não linear embora, de autores críticos à Modernidade Jurídica, o trabalho parte da conceito de instituição de Santi Romano para, a partir daí, estabelecer um diálogo qualificado entre o jurista italiano e outras escolas e autores que, da mesma forma, voltam-se à problemantização do modo pelo que o Direito é concebido a partir de fins do Século XVIII. Por meio do método dedutivo de abordagem, e lançando mão da pesquisa bibliográfica é que, então, foram escolhidos alguns traços centrais da obras romaniana : (a) antinormativismo; (b) anti-individualismo; (c) o direito visto ente objetivo e, por isso, traduzindo a organização social, sem relação com o ente estatal. A partir deles, a dissertação segue na tentativa de ver se e de que modo eles se fazem presentes ainda no cerne do pensamento da Escola História - com destaque aqui para Savigny -, e, ainda, no da Escola Positivista, de ênfase sociológica, francesa - sublinando neste passo o pensamento de Durkheim, Duguit e Hauriou (neste passo reunindo juristas anteriores ou contemporâneos a Romano). Seguindo a investigação - agora lançando mão de concepões de juristas posteriores a Santi Romano -, a obra destrinça ainda o pensamento decisionista de Carl Schmitt, como ainda, por fim, as concepções do historiador do Direito Paolo Grossi. Tudo isso como forma de engendrar um núcleo de posições teóricas defendidas por autores que, a despeito das flagrantes contradições existentes entre si, podem ser reunidos, em perspectiva histórica, num mesmo agrupamento de posições contestadoras do paradigma instaurado pela Modernidade Jurídica.In an attempt to establish an outline of the authors who were critical of Legal Modernity, our text takes the concept of institution in Santi Romano, in order to establish a dialogue between the Italian jurist and schools and other authors who also care about the questioning of the form that Law is designed in the late eighteenth century. Then, through the deductive method of approach and using the research literature, were chosen some central features of the works of Romano: (a) anti-normativism; (b) anti-individualism; (c) the Law as being objective, thereby reflecting the social organization, unrelated to the state. From them, our exposition follows in an attempt to see if and how these aspects are present in the heart of the 'Historical School' in the Philosophy of Law - in particular, Savigny - and also within the Positivist School, especially French and sociological - highlighting here the thought of Durkheim, Duguit, and Hauriou. Following the investigation, our work details the decisionist thought of Carl Schmitt, as well as the views of Paolo Grossi, historian of Law. All this as a way of engendering a core of theoretical positions defended by the authors who, despite the glaring contradictions between them, can be assembled in the same group of perspectives that challenges the legal paradigm introduced by Modernity
GARCÍA GUAL, C; GOMÁ, J; HERNANDEZ DE LA FUENTE, D. (2024) El estoicismo romano. Séneca, Epicteto, Marco Aurelio, Barcelona: Arpa
No full textReseña de GARCÍA GUAL, C; GOMÁ, J; HERNANDEZ DE LA FUENTE, D. (2024) El estoicismo romano. Séneca, Epicteto, Marco Aurelio, Barcelona: Arp
Ancient DNA study of the remains of putative infanticide victims from the Yewden Roman villa site at Hambleden, England
No full textPrevious analysis of the perinatal infant burials from Romano-British Yewden villa, Hambleden, indicated the practice of infanticide at that site. We attempted to determine whether this practice was specifically targeted at one sex or other by determining the sex of the infants using analysis of fragments of the amelogenin gene. We also analysed mtDNA in order to shed light on aspects of kinship. Thirty-three infants were analysed, and sex was successfully identified in 12. Seven were female, five male. No two infants shared identical mtDNA polymorphisms, indicating that all came from different mothers. Taken together with previous DNA results from perinatal remains from Romano-British sites where infanticide has been identified, they provide no evidence that manipulation of the sex ratio was a motivation for infanticide in Roman Britai
D. 41.1.36 (Iul. 13 dig.) e D. 12.1.18 pr. (Ulp. 7 disp.): tra causa traditionis e negotium contrahere in Giuliano
No full textThe study deals with the category of negotium in Salvius Iulianus. In this regard, the author examines D. 41.1.36 (Iul. 13 dig.) and D. 12.1.18 pr. (Ulp. 7 disp.), very well-known texts, concerning the topic of the causa traditionis, in which it is discussed whether the case of someone who has given a sum of money with the intention of donating to someone who has rather received it with the intention of borrowing should be considered a donation or a loan. The author excludes that the two texts and in particular D. 41.1.36 could bring arguments in support of the thesis that Julian developed a concept of negotium as an objective relationship between two distinct patrimonies, without any consideration of the will of the parties. On the contrary, from the few sure information that can be drawn from Ulpian’s text, it is clear that in the
assessment of the case and particularly on the existence of a causa donandi, Julian relied on a reconstructive process that looked very carefully at the will of the parties involved
Marton, north Lincolnshire: a Romano-British settlement in its context
No full textThis thesis seeks to reconstruct and interpret the form and extent of the Romano- British settlement at Marton, North Lincolnshire. The site at Marton has previously been the subject of no formal programme of archaeological research. However it offers a rich potential for applying non-intrusive archaeological survey, and this study is based on the results obtained from a combination of different survey techniques. Although the site has received very little formal archaeological attention in the past, uncontrolled metal-detection has been intensive over recent years. The unrecorded leaching of material, coupled with the diverse range of artefacts known to have been retrieved in detection has been one of the principal catalysts behind the adoption of this survey. The data was collected both from previous aerial photographic surveys and metal detectorists with whom a working relationship had been established, and in geophysical survey and field walking undertaken by the author. Survey methodology and the results of the different components of the survey are presented in chapters 2 to 6. Initial interpretations of the features identified from the aerial photographic and geophysical survey are proposed and the main chronological and spatial trends m the distribution of pottery, coins and other small finds are summarised. Chapter 7 compares the results obtained from the different classes of evidence and refines the interpretations offered for the development of the site through time and space. Specific issues considered are the origins of the settlement, its internal organisation and extent and its relationship with nearby Littleborough. The final chapter compares Marton with other sites in the region and sites of a similar type in Roman Britain. A series of hypotheses are then proposed concerning the nature of the site and its function and evolution in its local landscape
Corrigendum to Patterns of ascending aortic dilatation and predictors of surgical replacement of the aorta: A comparison of bicuspid and tricuspid aortic valve patients over eight years of follow-up “J Mol Cell Cardiol. 2019 Oct;135:31–39. PMID: 31348923” (Journal of Molecular and Cellular Cardiology (2019) 135 (31–39), (S0022282819300495), (10.1016/j.yjmcc.2019.07.010))
No full textThe authors regret that the author name of Romano and Raffa are incorrect. The corrected author's name are Romano G and Raffa GM. The authors would like to apologise for any inconvenience caused
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