Search results for "upe"
showing 10 items of 7447 documents
Analytical approach for the mix design optimisation of bituminous mixtures with crumb rubber
2018
The present paper provides a basis for defining a mix design method specifically tailored to rubberised asphalt that takes into account the behaviour of crumb rubber. An analytical approach to quantifying the recovered deformation of crumb rubber in the post-compaction phase has been developed in order to adjust the number of gyrations proposed by the Superpave method for compacting specimens of hot mix asphalt using a Superpave gyratory compactor. The maximum allowable amount of rubber has been calculated. Finally, a step-by-step protocol has been proposed in order to fabricate and compact crumb rubber modified mixtures with the gyratory compactor.
Increased Stability of Rubber-Modified Asphalt Mixtures to Swelling, Expansion and Rebound Effect during Post-Compaction
2017
The application of bituminous mixtures modified with rubber from scrap-tires require attention and care during mixing and compaction. Rubber modifies the properties because it reacts in the internal structure of bitumen at high temperatures changing the performance of the mixture (interaction process of solvents with binder-rubber aggregate). The main change is the increasing of the viscosity and elasticity of the binder due to the larger sizes of the rubber particles by dry process but, this positive effect is counteracted by short mixing times, compared to wet technology, and due to the transport processes, curing time and post-compaction of the mixtures. Therefore, negative effects as sw…
Investigation of the magnetic field fluctuation and implementation of a temperature and pressure stabilization at SHIPTRAP
2011
Abstract Penning traps have proven to be powerful tools for the determination of nuclear masses with high accuracy. A crucial parameter for precision mass measurements in Penning traps is the accurate determination of the magnetic-field strength. However, the magnetic field of a superconducting magnet is not constant in time, but changes due to intrinsic effects of the solenoid and external perturbations. These effects have been investigated for SHIPTRAP. Furthermore, a stabilization of the temperature in the magnet bore as well as of the pressure in the liquid-helium cryostat has been implemented. Thus, the magnetic-field related uncertainties have been reduced to 7(6)×10−11/h.
Crystal Fields in PrX3 (X=In, Tl, Pb, Sn) Intermetallic Compounds with Cu3Au Structure
1977
We have determined the crystal field splittings of Pr3+ in PrIn3, PrTl3, PrPb3, and PrSn3 by inelastic neutron scattering. The values of the deduced crystal field parameters are found to depend strongly on the constituent X, though all systems have nonmagnetic ground-states. The line widths in the different systems are compared.
Correlation of primary and secondary relaxations in a supercooled liquid
2006
The widespread assumption that primary and secondary relaxations in glass-forming materials are independent processes is scrutinized using spin-lattice relaxation weighted stimulated-echo spectroscopy. This nuclear magnetic resonance (NMR) technique is simultaneously sensitive to the dynamics on well-separated time scales. For the deeply supercooled liquid sorbitol, which exhibits a strong secondary relaxation, the primary relaxation (that is observable using NMR) can be modified by suppressing the contributions of those subensembles which are characterized by relatively slow secondary relaxations. This is clear evidence for a correlation between primary and secondary relaxation times. In t…
On melting of two-dimensional monolayer films
1996
The melting of two-dimensional films formed on the (100) fcc crystal is studied by Monte Carlo simulation. The results obtained suggest that in systems with only weakly corrugated surface potential, exhibiting the hexagonal close packed solid structure, the melting transition is followed by the lsing-like transition as predicted by the theory of Nelson and Halperin. In the case of highly corrugated surface potential, the film forms registered structure which disorders gradually as the temperature is raised.
Unravelling the fine structure of stacked bipyridine diamine-derived C-3-discotics as determined by X-ray diffraction, quantum-chemical calculations,…
2011
An in depth investigation of the fine structure adopted by the helical stacks of C3-discotics 1 incorporating three 3,3'-diamino-2,2'-bipyridine units is described. In the bulk the molecules display liquid crystalline behaviour in a temperature window of >300 K and an ordered rectangular columnar mesophase (Colro) with an inter-disc distance of 3.4 Å is assigned. X-Ray diffraction on aligned samples has also revealed a helical superstructure in the liquid crystalline state, and a rotation angle of 13–16° between consecutive discs. The proposed superstructure in the bulk phase has been further substantiated by a combination of quantum-chemical calculations and solid-state NMR spectroscopy…
DOMAIN AND MOLECULAR SUPERLATTICE STRUCTURE OF DODECANETHIOL SELF-ASSEMBLED ON AU(111)
1994
Annealed organic monolayers of dodecanethiol (CH3(CH2)11SH) self-assembled on Au(111) have been investigated by scanning tunnelling microscopy. By using very high tunnelling resistances (TOMEGA) we find evidence of well-ordered molecular domains at room temperature and observe two different types of c(4 x 2) superlattice structures with the same rectangular unit cell. In contrast to theoretical calculations each unit cell contains four inequivalent molecules. Possible reasons for this discrepancy are discussed.
Le créancier d'un GIE qui ne déclare pas sa créance à la procédure collective ouverte à l'égard de chaque membre cause un préjudice aux cautions subr…
2002
International audience; (Com. 20 févr. 2001, Di Maggio et Denivelle c/ CRCAM de Charente-Périgord, pourvoi n° 97-14.256, arrêt n° 369 FS-P)
"Per via di levare". Scavare e sottrarre in architettura
2014
Scavare, dal latino excavare (ex-cavare), possiede etimologicamente il significato di “rendere cavo” mediante l’azione del subtrahĕre (sottrarre). Tuttavia il significato del termine all’interno della sua necessaria disambiguazione non può essere inteso limitatamente alla luce dell’etimologia latina. Si dirà allora che la tecnica dello scavo è opposta e complementare alla tecnica dell’accumulazione. È un procedere per sottrazione di volumi, un operare in negativo per asportazione di materiale, erodendo, cavando ed estraendo. Il saggio indaga, attraverso un intenso per quanto lacunoso excursus tra le esperienze della contemporaneità l'emergere del archetipico della dimensione ipogea dell’arc…