1,354,341 research outputs found
Giuseppe Brotzu and the Discovery of Cephalosporins
Get PDFGiuseppe Brotzu (1895-1976), for over thirthy years Professor of Hygiene in the Medical Faculty and Rector
(1936-1945) of the University of Cagliari, was also superintendent of Public Health during the campaign for
the eradication of malaria in Sardinia.
As a scientist, his fame is due to the discovery of cephalosporins that he made in Cagliari, at the end of the 2nd World War. He isolated from the outfalls of a local sewage a microorganism, identified as Cephalosporium acremonium, whose cultures inhibited several important Gram negatives as Salmonella typhi and Brucella Melitensis.
Even if he was aware of the importance of his discovery, owing to the lack of facilities and financial support
he was unable to study further the activity of the fungus.
Thus, in the year 1946, after the publication of his results on the journal "Lavori dell'Istituto di Igiene di
Cagliari", he sent the fungus to the Laboratory of Pathology at Oxford University. Here Edward Abraham,
who had been part of Florey team in the study of penillin, succeeded in producing the Cephalosporin
antibiotics, one of the most important tool in the therapy of infectious diseases.
For his discoveries Brotzu was awarded in 1971 the honorary degree in Science by Oxford University
Otro título: Ciclo de Conferencias Científicas de la Fundación Bristol
No full textManuel Moreno López. Giuseppe BrotzuBienvenida al acto científico -- Min. 00.43: Manuel Moreno López presenta a Giuseppe Brotzu realizando un recorrido por su carrera profesional y sus logros -- Min. 06.32: Giuseppe Brotzu, en italiano, comienza su conferencia sobre los antibiótico
The Syntesis of zeolites from hydrothermal experiments on Sardinian Tertiary clinoptilolite-bearing ignibrites.
No full textComparison between mechanical properties and structures of a rolled and a 3D-printed stainless steel
Get PDFIn this work selective laser melting was successfully utilized to produce 316 stainless steel bulk specimens. Although this technology provides many advantages compared to conventional shaping processes, little residual porosity may be a problem for some applications where high strength is required. The objective of this work was to determine, through data analysis, a mechanical and metallographic comparison between thin sheets made by using different manufacturing technologies: Cold rolling and additive manufacturing. This comparison was useful to understand whether it could be more advantageous to use the prototyping for new mechanical components. The results show that the additive manufactured steel, due to its microstructure, is characterized by a higher yield strength and by a lower elongation and ultimate tensile strength
I materiali compositi a matrice di alluminio: struttura e comportamento alla frattura
No full textSono state studiate le strutture e le caratteristiche meccaniche con particolare riferimento alla meccancia della frattura (propagazione della cricca di fatica e tenacità) di 4 composti a matrice di alluminio e rinforzo ceramico discontinuomicrostructures and mechanical properties (fatigue crack growth rate and toughness) of 4 different alluminium Matrix composites have been studie
Fracture behaviour of alloys for a new laser ranged satellite
Get PDFA new laser-ranged satellite called LARES 2 (Laser Relativity Satellite 2) has been recently designed for accurate tests of Einsten's theory of General Relativity and space geodesy. Some high density alloys (8.6-9.3 g/dm3) have been studied and characterised for producing the LARES 2 passive satellite. The considered materials were Copper and Nickel based alloys that have been produced and characterised. Aim of this work was to analyse their fracture behaviour that is a requirement for materials to be used for space applications. Fracture tests have been carried out on several specimens and fracture surfaces have been analysed
Investigation on some factors affecting crack formation in high resistance aluminum alloys
Get PDFAluminum alloys having good mechanical properties are Al-ZnMg alloys (7xxx) and Al-Cu-Li alloys (Weldalite). These alloys may be subjected to stress corrosion cracking. In order to overcome this problem the Al 7050 alloy has been developed and it is widely used for aerospace applications. Despite that, some components made of this alloy cracked during the manufacturing process including machining and chemical anodization. In a previous work cracked Al 7050 components have been analyzed in order to identify possible causes of crack formation. In this work the susceptibility of this alloy to intergranular corrosion has been analysed and compared with that of other high resistance aluminum alloy
Fracture behaviour of alloys for a new laser ranged satellite
Get PDFA new laser-ranged satellite called LARES 2 (Laser Relativity Satellite 2) has been recently designed for accurate tests of Einsten's theory of General Relativity and space geodesy. Some high density alloys (8.6-9.3 g/dm3) have been studied and characterised for producing the LARES 2 passive satellite. The considered materials were Copper and Nickel based alloys that have been produced and characterised. Aim of this work was to analyse their fracture behaviour that is a requirement for materials to be used for space applications. Fracture tests have been carried out on several specimens and fracture surfaces have been analysed
The search for the parental magma of the high-K calc-alkaline igeous rock series in the southernmost Sardinia Batholith
No full textImpiego di sensori in fibra ottica per il monitoraggio di fratture statiche e dinamiche
No full textViene presentata una rassegna di indagini effettuate sull’impiego di sensori in fibra ottica FBG
(Fiber Bragg Grating) per il monitoraggio di fratture statiche e dinamiche in diversi campi applicativi
dell’ingegneria.
Viene illustrato:
1. Il monitoraggio di una frattura muraria di un arco di un importante edificio storico (scuola Grande di San
Rocco a Venezia) valutando la risposta dei sensori installati in funzione della quantità di visitatori presenti
nell’edificio.
2. Il monitoraggio di una frattura presente sulla zampa anteriore di appoggio del cavallo della statua di
Bartolomeo Colleoni a Venezia
3. Il monitoraggio della propagazione di cricche di fatica su materiali compositi in fibra di carbonio e su leghe di
allumini
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