7,428 research outputs found
Ultrafast process in bacterial antennas studied by nonlinear polarization spectroscopy (frequence domain)
Thermo-mechanical analysis of dental silicone polymers
Soft lining materials are used to replace the inner surface of a conventional complete denture, especially for weak elderly patients, with delicate health who cannot tolerate the hard acrylic denture base. Most of these patients have fragile supporting mucosa, excessive residual ridge resorption, particularly on the mandibular arch. The application of a soft liner to the mandibular denture allows absorbing impact forces during mastication and relieving oral mucosa. Actually, the silicone rubbers constitute the main family of commercialised soft lining materials. This study was conducted to understand the relationships between the mechanical properties and the physical structure of polysiloxanes. For this purpose, a series of polysiloxanes of various chemical compositions have been investigated. The evolution of their physical structure as a function of temperature has been followed by differential scanning calorimetry (DSC). In order to facilitate comparisons, the mechanical modulus has been analysed upon the same heating rate using dynamic mechanical analysis (DMA). Polysiloxanes actually commercialised as soft denture liners are three-dimensional networks: the flexibility of chains allows a crystalline organisation in an amorphous phase leading to the low value of the shear modulus. The dynamic mechanical analysis shows that they are used in the rubbery state. So, polysiloxanes have steady mechanical properties during physiological utilisation
Proton-induced magnetic order in carbon: SQUID measurements
In this work we have studied systematically the changes in the magnetic
behavior of highly oriented pyrolytic graphite (HOPG) samples after proton
irradiation in the MeV energy range. Superconducting quantum interferometer
device (SQUID) results obtained from samples with thousands of localized spots
of micrometer size as well on samples irradiated with a broad beam confirm
previously reported results. Both, the para- and ferromagnetic contributions
depend strongly on the irradiation details. The results indicate that the
magnetic moment at saturation of spots of micrometer size is of the order of
emu.Comment: Invited contribution at ICACS2006 to be published in Nucl. Instr. and
Meth. B. 8 pages and 6 figure
Small scale irrigation using collector wells pilot project - Zimbabwe. Final report October 1992 - January 1996
Tropical Krichever construction for the non-periodic box and ball system
A solution for an initial value problem of the box and ball system is
constructed from a solution of the periodic box and ball system. The
construction is done through a specific limiting process based on the theory of
tropical geometry. This method gives a tropical analogue of the Krichever
construction, which is an algebro-geometric method to construct exact solutions
to integrable systems, for the non-periodic system.Comment: 13 pages, 1 figur
A recursive paradigm for aligning observed behavior of large structured process models
The alignment of observed and modeled behavior is a crucial problem in process mining, since it opens the door for conformance checking and enhancement of process models. The state of the art techniques for the computation of alignments rely on a full exploration of the combination of the model state space and the observed behavior (an event log), which hampers their applicability for large instances. This paper presents a fresh view to the alignment problem: the computation of alignments is casted as the resolution of Integer Linear Programming models, where the user can decide the granularity of the alignment steps. Moreover, a novel recursive strategy is used to split
the problem into small pieces, exponentially reducing the complexity of the ILP models to be solved. The contributions of this paper represent a promising alternative to fight the inherent complexity of computing alignments for large instances.Peer ReviewedPostprint (author's final draft
Meissner effect in honeycomb arrays of multi-walled carbon nanotubes
We report Meissner effect for type-II superconductors with a maximum Tc of 19
K, which is the highest value among those in new-carbon related
superconductors, found in the honeycomb arrays of multi-walled CNTs (MWNTs).
Drastic reduction of ferromagnetic catalyst and efficient growth of MWNTs by
deoxidization of catalyst make the finding possible. The weak magnetic
anisotropy, superconductive coherence length (- 7 nm), and disappearance of the
Meissner effect after dissolving array structure indicate that the graphite
structure of an MWNT and those intertube coupling in the honeycomb array are
dominant factors for the mechanism.Comment: 6 page
Beyond the standard model physics at RHIC in polarized pp collision
A polarized hadron collider experiment must have a great discovery potential
for a search of physics beyond the standard model. Experimental data of various
symmetry tests at RHIC are going to be obtained within a few years. The author
developed a simulation tool, studying a sensitivity of hunting contact
interaction at RHIC by measuring parity violating spin asymmetries.Comment: 8 pages, 9 figure, Proc. of Praha-SPIN-200
- …