15,195 research outputs found
Leonardo e il Novecento: dai futuristi alle mostre leonardesche
No full textIl saggio in catalogo illustra la sezione 8 della mostra "Leonardo di carta in carta. La costruzione del mito fra Ottocento e Novecento", a cura di S. Alessandri, M. Ceriana, S. Mammana (comitato scientifico: S. Alessandri, F. Barbagli, M. Ceriana, D. Colombo, S. Mammana, F. Tognoni, A. Tura, F. Valli, C. Vecce), tenutasi alla Biblioteca Nazionale Centrale di Firenze (BNCF) dal 5 dicembre 2019 al 14 marzo 2020. La sezione della mostra e il saggio sono dedicati a una breve rassegna dello sviluppo del mito di Leonardo a Vinci nei primi decenni del Novecento: dalla irrisione del mito della Gioconda fatto da artisti come Malevic, Duchamp, Picabia, Eluard, Leger e dai futuristi, che, però consideravano il maestro rinascimentale un modello di riferimento, all'influenza esercitata su Balla, Carrà, Fontana, fino alla sequenza di mostre che hanno sancito la definizione del mito di Leonardo scienziato, genio precursore e universale, fatto proprio dalla propaganda fascista, soprattutto con la Mostra Leonardesca del 1939 al Palazzo dell'Arte di Milano.The essay of the catalogue presents the section no. 8 of the exhibition "Leonardo di carta in carta. La costruzione del mito fra Ottocento e Novecento", ed. by S. Alessandri, M. Ceriana, S. Mammana (Scientifi Committee: S. Alessandri, F. Barbagli, M. Ceriana, D. Colombo, S. Mammana, F. Tognoni, A. Tura, F. Valli, C. Vecce), held at Biblioteca Nazionale Centrale in Firenze (BNCF) from December 5 2019 to March 14 2020. The exhibition section and the essay are dedicated to a short portrayal of the development of the myth of Leonardo da Vinci in earlier Twentieth-Century: the derision of myth of Gioconda by artists such as Malevic, Duchamp, Picabia, Eluard, Leger, and by futurists, who, anyway, considered him a model, as well as the influence on Balla, Carrà, and Fontana; moreover the sequence of shows dedicated to Leonardo “scientist”, pioneer and all-round genius, used by propaganda of Fascism, above all thanks to exhibition Leonardesca, held at Palazzo dell’Arte in Milan in 1939
Gli stranieri e la sicurezza
No full textIl contributo affronta due temi. Il primo è costituito dalle politiche di controllo esterne e interne volte a contrastare e ridurre l'immigrazione irregolare; il secondo dal contributo che gli stranieri danno ad alcuni reati inItalia. Lo studio è condotto in una prospettiva di medio periodo e riconduce i principali cambiamenti a fattori politici, geografici e legati al ciclo migratori
Moderating Urbanization and Managing Growth: How Can Colombo Prevent the Emerging Chaos?
No full textThis paper examines urbanization trends, the growth of Colombo and its present state of development. It looks at the approaches to the planned interventions in the city and demonstrates how a uni-directional urban development has had a detrimental impactColombo, urban development, managing urbanization, planning, housing,
Application of ammonium phosphate to marble. Investigation of newly-formed calcium phosphates with synchrotron light and high lateral resolution FTIR microspectroscopy
No full textInorganic-mineral treatments exhibit great potentialities for the consolidation of stone materials due to their high compatibility with the substrate. Their reaction mechanism is based on the diffusion, inside weathered stone matrixes, of water soluble precursors that, reacting with the substrate, supply a crystal network able to reconnect detached grain boundaries. The newly-formed crystalline phases are stable and due to their low solubility provide a passivating action toward atmospheric agents even in acid environment. Diammonium hydrogen phosphate [DAP, (NH4)2HPO4] has been recently suggested for the treatment of sedimentary and metamorphic carbonatic decayed stones. The reaction of DAP with calcite of the substrate involves a pseudomorphic replacement and favours the growth of calcium phosphates inside the porosity. Preliminary studies (Matteini et al., 2013; Possenti et al., 2016) show that the reaction at room temperature is non-stoichiometric and induces the formation of hydroxyapatite [HAP, Ca5(PO4)3(OH)] (Ni & Ratner, 2003) and other metastable phases. In this pilot study we characterized the complex assemblages of calcium phosphates formed after DAP treatments on Carrara marble specimens with a multi-analytical approach (scanning electron microscopy, vibrational spectroscopies and powder X-ray diffraction). A set of quarried and thermally decayed samples were treated by poultice and capillarity using DAP solutions at different molarities. Ground-breaking techniques such as X-ray diffraction with synchrotron light in transmitting geometry and high lateral resolution FTIR microspectroscopy were employed to overcome some of the analytical limits of conventional approach, assessing the overall composition of main and trace phases as well as
their arrangement on the substrate. Preliminary findings show the formation of a shell-like layer around the calcite grains, composed by a mixture of crystalline and amorphous calcium phosphates; the formation of specific phases, their morphologies and the relative amount depend on the solution molarity and the treatment duration. Moreover, our data show a correlation between the kind of crystalline phase and its morphology and position within the shell structure.
Matteini, M., Colombo, C., Botticelli, G., Casati, M., Conti, C., Negrotti, R., Possenti, E., Realini M. (2013): Ammonium phosphates
to consolidate carbonatic stone materials: an inorganic-mineral treatment greatly promising. Proceedings of the Built Heritage
2013 Monitoring Conservation Management, 1278-1286.
Ni, M. & Ratner, B.D. (2003): Nacre surface transformation to hydroxyapatite in a phosphate buffer solution. Biomaterials, 24, 4323-
4331.
Possenti, E., Colombo, C., Bersani, D., Bertasa, M., Botteon, A., Conti, C., Lottici, P.P., Conti C. (2016): New insight on the
interaction of diammonium hydrogenphosphate conservation treatment with carbonatic substrates: a multi-analytical approach.
Microchem. J., 127, 79-86
Advanced Modelling of Thermal Plasmas for Industrial Applications
No full textAdvanced Modelling of Thermal Plasmas for Industrial Applications
V. Colombo, E. Ghedini
Department of Mechanical Engineering (D.I.E.M.) and Research Center for Applied Mathematics (C.I.R.A.M.)
Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy
Modeling results are presented for different industrial thermal plasma sources using a customized version of the commercial code FLUENT capable of 2D and 3D transient simulation with advanced CFD models that take into account turbulence effects using different approaches (Reynolds Stress Model and Large Eddy Simulation), species transport and radiation (Discrete Ordinate Model with interaction between radiation and solid surfaces). Simulations results are presented in order to show the capabilities of this modeling tool, which is very useful for the design of a wide range of atmospheric pressure thermal plasmas devices and applications, such as: ICPTs with injection of powders for spheroidization purposes (showing the trajectory and heating history of powders injected in the torch through a carrier gas together with their effect on the plasma discharge for various geometric, electric and operating conditions by means of an improved turbulent version of a 3-D previously developed code where the helicoidal coil and the gas injection section of industrial plasma torches are taken into account without geometry simplifications), twin-torch DC transferred arc plasma systems for waste treatment (showing time-dependent effects arising in the fluid flow and temperature distribution of a plasma transferred electric arc discharge generated between two suspended metallic electrodes used inside a plasma furnace for hazardous waste incineration with turbulence effects taken into account using a RANS approach, as well as the effect on the discharge characteristics of using different types of plasma gas (air and Ar/H2 mixtures), for various geometric and operating conditions), DC non-transferred arc torch for plasma spraying (3-D time dependent model to simulate the behaviour of such a device without any external assumption on the anode restriking and attachment and to simulate also the downstream expansion of the plasma jet after the torch nozzle using a LES turbulence model).
D. Bernardi, V. Colombo, E. Ghedini, A. Mentrelli, Pure and Applied Chemistry, 77, pp. 359 – 372, (2005).
D. Bernardi, V. Colombo, E. Ghedini, A. Mentrelli, T.Trombetti, Czechoslovak Journal of Physics. 54, pp. C489 - C515 (2004).
D. Bernardi, V. Colombo, E. Ghedini, A. Mentrelli, T. Trombetti, IEEE Transactions on Plasma Science, 33, pp. 424–425 (2005).
D. Bernardi, V. Colombo, E. Ghedini, A. Mentrelli, IEEE Transactions on Plasma Science, 33, pp. 426–427 (2005).
D. Bernardi, V. Colombo, E. Ghedini, S. Melini, A. Mentrelli, Three-dimensional time-dependent modelling of magnetically deflected transferred arc, IEEE Transaction On Plasma Science 33, 428-429 (2005).
V. Colombo, E. Ghedini, Time Dependent 3-D Simulation of a DC Non-Transferred Arc Plasma Torch: Anode Attachment and Downstream Region Effects, Proc. of the 17th Int. Symp. on Plasma Chemistry-ISPC17 (2005).
V. Colombo, E. Ghedini, A. Mentrelli, E. Malfa, 3-D Modelling of DC Transferred arc Twin Torch for Asbestos Inertization. In Nuclear Reactor Physics. A collection of papers dedicated to Silvio Edoardo Corno, Torino, C.L.U.T., pp. 169 - 196 (2005).
V. Colombo, E. Ghedini, Time-Dependent 3-D Modelling Of Dc Transferred Arc Twin Torch, High Technology Plasma Processes 9 - HTPP9, St. Petersburg (2006)
Modelling and Comparison of Different Design Solutions for DC Transferred Arc Plasma Cutting Torches
No full textModelling and Comparison of Different Design Solutions for DC Transferred Arc
Plasma Cutting Torches
V. Colombo, E. Ghedini
Department of Mechanical Engineering (D.I.E.M.) and Research Center for Applied Mathematics (C.I.R.A.M.)
Università di Bologna, Via Saragozza 8, 40123 Bologna, Italy
S. Dallavalle, M. Vancini,
Cebora S.p.A., Via Andrea Costa 24, 40057 Cadriano di Granarolo, Italy
The aim of this work is to investigate by means of a 2-D and 3-D FLUENT© based numerical model the behaviour of different types of transferred arc dual gas plasma torches used for cutting of metallic materials, putting into evidence the physical reasons for the industrial success of various design and process solutions appeared over the last years, such as: secondary gas swirl injections with different directions, various different approaches for the geometry of the plasma chamber, the effect of externally superimposed magnetic fields. Flow and heat transfer equations are solved with coupled electromagnetic ones, for a LTE optically thin plasma, while turbulence phenomena are taken into account by means of a k-ε RNG model. Simulations include a prediction of the thermal behaviour of the solid components of the torch head, including electrode and hafnium insert, thermal histories and trajectories of hafnium oxide particles emitted from it under idealized conditions and the efficiency of nozzle and electrode cooling systems in various operating conditions including gas mixtures (O2/air, H35/N2, N2/N2). Radiation is included in the calculation of heat transfer to the surfaces of the components using a customized Discrete Ordinate (DO) model. Results obtained from the simulations of one of the plasma torches here considered are also compared with experimental measurements in order to perform a validation of the model for what concerns pressure values in different regions of the device, and the gas mass flow rate during the working phase. For this purpose two suitably modified plasma torches with pressure and temperature measurement systems have been designed and used during realistic cutting conditions.
V. Colombo, E. Ghedini, S. Dallavalle, M. Vancini, 3-D Fluidynamic and Plasma Characterization of DC Transferred Arc Plasma Torches for Metal Cutting. 17th International Symposium on Plasma Chemistry (ISPC-17). Toronto, august 2005.
V. Colombo, E. Ghedini, G. Masini, D. Russo, S. Dallavalle, M. Vancini, 2-D And 3-D Fluidynamic And Plasma Characterization Of Dc Transferred Arc Plasma Torches For Metal Cutting, High Technology Plasma Processes 9 -HTPP9, St. Petersburg (2006); in press on Journal of High Temperature Material Processes
Antitumor Platinum(II) Hybrid Compounds Based on a Glucosylglycerol Scaffold
No full textPlatinum(II) drugs such as cisplatin, carboplatin and oxaliplatin are antineoplastic drugs
clinically available for the treatment of different kinds of cancers, including ovarian
carcinoma. However, their use is limited by the occurrence of severe systemic side effects and
resistance [1, 2]. For these reasons, the development of new platinum-based compounds
endowed with higher selectivity against cancer cells and able to overcome resistance is an
active research field. A promising strategy to pursuit these goals is the design of hybrid
platinum(II) compounds bearing bioactive ligands able to selectively target cancer cells,
improve the platinum-mediated antitumor activity and/or overcome resistance by interacting
with selected targets known for their involvement in cancer resistance [3]. In this context, due
to its peculiar structure, 2-O-β-D-glucosylglycerol (a natural compound named Lilioside B)
[4] could be efficiently used at the same time as the complexing agent of platinum(II) and as
the point of attachment of cancer involved bioactive compounds. Thus, the present
communication will show some preliminary results on the synthesis and cytotoxicity data, on
ovarian cancer cells, of a water soluble platinum(II) hybrid compound in which, similarly to
carboplatin, a properly modified 2-O-β-D-glucosylglycerol is able to complex platinum(II).
References
1. Khoury, A.; Deo, K.M.; Aldrich-Wright, J.R. J. Inorg. Biochem., 2020, 207, 111070.
2. Rottenberg, S., Disler, C., & Perego, P. Nature reviews. Cancer, 2021, 21, 37.
3. Zuccolo, M,; Arrighetti, N.; Perego, P.; Colombo, D. Curr. Med. Chem., 2022, 29, 2566.
4. Kaneda, M.; Mizutani, K.; Takahashi, Y.; Kurono, G.; Nishikawa, Y. Tetrahedron Lett., 1974, 15,
3937
Measurement of the mass difference m(D-s(+))-m(D+) at CDF II
No full textWe present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)
Correction to: Biaxial bending of SFRC slabs: Is conventional reinforcement necessary? (Materials and Structures, (2019), 52, 1, (1), 10.1617/s11527-018-1302-0)
No full textThe article ‘‘Biaxial bending of SFRC slabs: Is conventional reinforcement necessary?’’, written by Marco di Prisco, Matteo Colombo and Ali Pourzarabi, was originally published electronically on the publisher’s Internet portal (currently SpringerLink) on 22 December 2018 without open access. The copyright of the article changed in December 2019 to The Author(s) 2019, and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made
Da solução ao problema: um estudo sobre os conflitos, os impactos sócio-ambientais e as representações sociais envolvidas no uso e na gestão da água do aquífero Karst no município de Colombo (PR)
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciencias Humanas. Programa de Pós-graduação em Sociologia PolíticaEsta dissertação trata das representações sociais dos sujeitos envolvidos no uso e na gestão da água do Aqüífero Karst no Município de Colombo (PR), desde o início da sua utilização, em 1995, até os dias atuais. A exploração deste aqüífero, que no seu início tratava-se de uma solução institucional para o problema da falta de água na área urbana de Colombo, tornou-se o cenário de conflitos e impactos sócio-ambientais. Sob a luz do modelo de análise das representações sociais e da gestão patrimonial dos recursos naturais, analisam-se os fatores comuns do conflito e do uso da água entre três categorias de sujeitos envolvidos no uso e gestão da água do Aqüífero Karst: Agricultores, Técnicos da Sanepar e Órgãos Públicos. A pesquisa apontou que o conflito se manifestara, de um lado, pelos agricultores que alegavam a exploração irracional do aqüífero interferindo diretamente na disponibilidade de água dos mesmos para a irrigação da agricultura; e do outro lado, pela Sanepar que alegava a impossibilidade de interromper a captação do aqüífero em função de ser a única solução viável para atender a demanda por água em Colombo. Os resultados da análise das representações sociais dos sujeitos envolvidos, tanto sobre o conflito como em relação aos significados do uso da água, apontaram uma vinculação entre as representações dos sujeitos com o papel social que os mesmos desenvolvem. Na categoria dos Agricultores, os resultados demonstraram que a água representa a manutenção tanto da sobrevivência física como da renda econômica familiar dos sujeitos, sendo causa motivadora do conflito. Na categoria dos Técnicos da Sanepar os resultados vincularam com uma das missões da empresa, o abastecimento público. E nos Órgãos Públicos, os resultados relacionaram-se com a missão social que os mesmos representam, como a gestão, fiscalização, licenciamento ambiental e mediação de conflitos sociais e ambientais. This thesis deals with the social representations of the subjects involved in the use and the management of the water on Karst Aquifer in the City of Colombo (PR), since the beginning of its use, in 1995, until the current days. The exploration of this aquifer, that in its beginning it was about an institutional solution for the problem of the water lack in the urban area of Colombo, became the partner-ambient scene of conflicts and impacts. It was used in this thesis the model of analysis of the social representations and the patrimonial management of the natural resources. One analyzed the common factors of the conflict and of the use of the water on three categories of involved citizens in the use and management of Karst Aquifer water: Farmers, Technicians of Sanepar Company and Public Agencies. The research indicated that the conflict expressed, on the one side, by the farmers claiming that the irrational exploitation of Karst Aquifer interfered directly on the availability of water from them for irrigation agriculture. The other side, by Sanepar claiming the impossibility of stops the capture of this Aquifer in line to be the only viable solution to meet the demand for water in Colombo City. The results of analysis of social representations of the subjects involved, as much on the conflict as in relation to the meanings of the use of the water, pointed a linkage between the representations of the subjects with the social role that they develop. In the category of farmers, the results showed that the water represents both maintenance of the physical survival as of the familiar economic income of the citizens, being the motivating factor of the conflict. In the category of Technicians of Sanepar Company, the results linked with one of the missions of the company, the supply public. And in the Public Agencies, the results related with the social mission that they represent, as the management, supervision, licensing and environmental mediation of social conflicts and environmental
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