Search results for "Geometric"
showing 10 items of 652 documents
Epistemic and didactic values of the demonstrative process in different cultures: a case study in Geometry with Chinese and Italian students
2011
Mechanical and microstructural characterization of titanium gr.5 parts produced by different manufacturing routes
2022
Abstract In recent years, the aircraft industry has shifted its preference for metal parts to titanium and its alloys, such as the high-strength Titanium Grade5 alloy. Because of Titanium Grade 5 limited formability at ambient temperature, forming operations on this material require high temperatures. In these conditions, a peculiar microstructure evolves as a result of the heating and deformation cycles, which has a significant impact on formability and product quality. On the other hand, additive manufacturing technologies, as selective laser melting and electron beam melting, are increasingly being used and are replacing more traditional approaches such as machining and forging. Fundamen…
Development of helium coolant DEMO first wall model for SYCOMORE system code based on HCLL concept
2018
Abstract The conceptual design of the demonstration fusion power reactor, known as DEMO, is ongoing and several reactor configurations have to be investigated by exploring different design parameters. For these reasons, within the European framework, systems codes like SYCOMORE (SYstem COde for MOdelling tokamak REactor) have been developed. SYCOMORE includes several specific modules, one of which is aimed to define a suitable design of the helium breeding blanket. The research activity has been devoted to improve the method to define automatically the First Wall design starting from thermal-hydraulic and thermo-mechanical considerations, using analytical design formulae and, also, taking i…
Volume-convergent sequences of Haken 3-manifolds
2003
Abstract Let M be a closed orientable 3-manifold and let Vol(M) denote its Gromov simplicial volume. This paper is devoted to the study of sequences of non-zero degree maps f i :M→N i to Haken manifolds. We prove that any sequence of Haken manifolds (Ni,fi), satisfying limi→∞deg(fi)×Vol(Ni)=Vol(M) is finite up to homeomorphism. As an application, we deduce from this fact that any closed orientable 3-manifold with zero Gromov simplicial volume and in particular any graph manifold dominates at most finitely many Haken 3-manifolds. To cite this article: P. Derbez, C. R. Acad. Sci. Paris, Ser. I 336 (2003).
A tractor mounted scanning LIDAR for the non-destructive measurement of vegetative volume and surface area of tree-row plantations: A comparison with…
2009
The use of a low-cost tractor-mounted scanning Light Detection and Ranging (LIDAR) system for capable of making non-destructive recordings of tree-row structure in orchards and vineyards is described. Field tests consisted of several LIDAR measurements on both sides of the crop row, before and after defoliation of selected trees. Summary parameters describing the tree-row volume and the total crop surface area viewed by the LIDAR (expressed as a ratio with ground surface area) were derived using a suitable numerical algorithm. The results for apple and pear orchards and a wine producing vineyard were shown to be in reasonable agreement with the results derived from a destructive leaf sampli…
Conversion of Existing Roundabouts into Turbo-Roundabouts: Case Studies from Real World
2012
Compared with roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of vehicles passing through the intersection, they both can improve safety conditions at the junction. Moreover, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. The present paper has three main objectives: (1) to discuss general design criteria and functional principles of turbo roundabouts, (2) to give the geometr…
Turbo-Roundabouts: a Model to Evaluate Capacity, Delays, Queues and Level of Service
2012
A turbo roundabout is a particular type of roundabout where entering and circulating lanes are bounded by traffic signs and by non-mountable curbs. The physical separation between lanes, both at entries and on the ring, helps to prevent side collisions crossing the roundabout. The main advantages of turbo roundabouts are: i) reduction in the number of potential conflict points; ii) lower speed of vehicles passing through the intersection; iii) safety conditions at the intersection due to lower risk of side-by-side accidents. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestri…
Rescaling principle for isolated essential singularities of quasiregular mappings
2012
We establish a rescaling theorem for isolated essential singularities of quasiregular mappings. As a consequence we show that the class of closed manifolds receiving a quasiregular mapping from a punctured unit ball with an essential singularity at the origin is exactly the class of closed quasiregularly elliptic manifolds, that is, closed manifolds receiving a non-constant quasiregular mapping from a Euclidean space.
Ģeometrisko zīmju un to uztveres semiotiska analīze latviešu zīmolos
2016
Ģeometriskās zīmes bieži tiek izmantotas zīmolvedībā un šķiet esam daļa no arhetipiska koda kultūras mantojuma pamatā, kas veido identitāti, tādēļ šī pētījuma mērķis ir izpētīt ģeometriskā raksta lomu valodas fenomenoloģijā, aprakstīt to kā zīmju sistēmu un veikt kvalitatīvu desmit Latvijas zīmolu, kuru logotipos ietvertas ģeometriskas zīmes, uztveres analīzi, lai noteiktu, ciktāl grafiskās zīmes iemieso zīmola vēstījumu saskaņā ar zīmolvedības, apziņas un modelēšanas sistēmu, kā arī ģeometriskā raksta un krāsu koda teorijām un interpretācijām. Zīmolu un pilotaptaujā iegūto datu semiotiska analīze liecina, ka ģeometriskās zīmes rosina daudzslāņainu sarunu par zīmola vēstījumu balstītu zīmes…
A suggested role for secondary flow in the stimulation of the cochlear hair cell
1985
The mammalian Corti organ and the reptilian basilar papilla are structures with a curved surface, which vibrate in a fluid medium. This paper is concerned with the role played by the geometric shape of these organs in cochlear hydrodynamics. In association with vibrating structures such as these organs, it can be expected that a stationary current will be initiated due to a nonlinear phenomenon in the boundary layer known as secondary flow. This phenomenon may explain the source of the mechanical nonlinearity in the cochlea.