17,580 research outputs found
Image Library: Acmopyle grayae A. Andruchow-Colombo, G. Rossetto-Harris, Tim J. Brodribb, M.A. Gandolfo, P. Wilf and Dacrycarpus engelhardti Wilf et Andruchow-Colombo
No full textFull-resolution image library of the two fossil Podocarpaceae species from Argentina- Acmopyle grayae A. Andruchow-Colombo, G. Rossetto-Harris, Tim J. Brodribb, M.A. Gandolfo, P. Wilf and Dacrycarpus engelhardti Wilf et Andruchow-Colombo - that were published here:Andruchow-Colombo, A., Rossetto-Harris, G., Brodribb, T. J., Gandolfo, M. A., and Wilf, P.. 2023. A new fossil Acmopyle with accessory transfusion tissue and potential reproductive buds: Direct evidence for ever-wet rainforests in Eocene Patagonia. American Journal of Botany e16221. https://doi.org/10.1002/ajb2.16221All photos taken by Peter Wilf.Please consult the provided Excel lookup table for the specimen data for both species and formal repository numbers.Please cite all material by repository number (not field number), prefixes MPEF-Pb, MAP-BAR, or USNM.Photo time stamp format is usually (YYYYMMDD HHMMSS).Please refer to the primary paper for all details and cite both the primary paper and this Figshare archive if you use these images.</p
Solution of Simple Reference Cases
No full textThis chapter presents the solution of simple reference cases of frame structures with the use of force method, displacement method or mixed method. The presented cases consider different loading condition (distributed loads, concentrated loads, thermal actions), different boundary conditions (rigid and/or elastic constraints), different geometrical configuration of frame and load (inclined rods, symmetrical and anti-symmetrical load and frame) and different mechanical behaviour of rods (elastic, axially deformable, infinitely rigid in bending)
Short Notes on Kinematic Analysis
No full textThis chapter presents a short overview on the main concepts related to the kinematic analysis of frame structures
Solution of Complex Frames
No full textThis chapter presents the solution of complex examples mixing the simple cases presented in the previous chapter. The worked examples are solved with the use of force method, displacement method and/or mixed method
Repertorio Italiano di Famiglie di parole. Dagli etimi ai significati per arricchire il lessico
No full textModerating 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,
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
De Lollis editore di Colombo
No full textPresentazione di Cesare De Lollis editore di Colombo per la "Raccolta Colombiana"
- …
