14,698 research outputs found
Basic Study of Synchronization in a Two Degree of Freedom, Duffing Based System
The issue of synchronization has been analyzed from many points of view since it was first
described in 17th century. Nowadays the theory that stands behind it is so developed,
it might be difficult to understand where it all comes from. This paper reminds the
key concepts of synchronization by examination of two coupled Duffing oscillators. It
describes also the origins of Duffing equation and proves its ability to behave chaotically
Parameterized complexity of machine scheduling: 15 open problems
Machine scheduling problems are a long-time key domain of algorithms and
complexity research. A novel approach to machine scheduling problems are
fixed-parameter algorithms. To stimulate this thriving research direction, we
propose 15 open questions in this area whose resolution we expect to lead to
the discovery of new approaches and techniques both in scheduling and
parameterized complexity theory.Comment: Version accepted to Computers & Operations Researc
The TESLA Time Projection Chamber
A large Time Projection Chamber is proposed as part of the tracking system
for a detector at the TESLA electron positron linear collider. Different
ongoing R&D studies are reviewed, stressing progress made on a new type readout
technique based on Micro-Pattern Gas Detectors.Comment: 5 pages, 8 figures; Proceeding for the topical Seminar on Innovative
Particle and Radiation Detectors Siena, 21-24 October 2002; to appear in
Nucl.Phys. B (Proceedings Supplement
Data Acquisition in the EUDET Project
The goal of the EUDET project is the development and construction of
infrastructure to permit detector R&D for the International Linear Collider
(ILC) with larger scale prototypes. It encompasses major detector components:
the vertex detector, the tracker and the calorimeters. We describe here the
status and plans of the project with emphasis on issues related to data
acquisition for future test beam experiments.Comment: 4 pages, 2 figures, to appear in the proceedings of Linear Collider
Workshop (LCWS06), Bangalore, Indi
Light Higgs production at the Compton Collider
We have studied the production of a light Higgs boson with a mass of 120 GeV
in photon-photon collisions at a Compton collider. The event generator for the
backgrounds to a Higgs signal due to bbbar and ccbar heavy quark pair
production in polarized gamma-gamma collisions is based on a complete
next-to-leading order (NLO) perturbative QCD calculation. For J_z=0 the large
double-logarithmic corrections up to four loops are also included. It is shown
that the two-photon width of the Higgs boson can be measured with high
statistical accuracy of about 2 % for integrated gamma-gamma luminosity in the
hard part of the spectrum of 40 fb**-1. As a result the total Higgs boson width
can be calculated in a model independent way to an accuracy of about 14 %Comment: submitted to the proceedings of the International Workshop on Linear
Colliders (LCWS99) at Sitges, Spain, 28 April - 5 May 199
Degradation of lignin β-aryl ether units in Arabidopsis thaliana expressing LigD, LigF and LigG from Sphingomonas paucimobilis SYK-6
Lignin is a major polymer in the secondary plant cell wall and composed of hydrophobic interlinked hydroxyphenylpropanoid units. The presence of lignin hampers conversion of plant biomass into biofuels; plants with modified lignin are therefore being investigated for increased digestibility. The bacterium Sphingomonas paucimobilis produces lignin-degrading enzymes including LigD, LigF and LigG involved in cleaving the most abundant lignin interunit linkage, the beta-aryl ether bond. In this study, we expressed the LigD, LigF and LigG (LigDFG) genes in Arabidopsis thaliana to introduce postlignification modifications into the lignin structure. The three enzymes were targeted to the secretory pathway. Phenolic metabolite profiling and 2D HSQC NMR of the transgenic lines showed an increase in oxidized guaiacyl and syringyl units without concomitant increase in oxidized beta-aryl ether units, showing lignin bond cleavage. Saccharification yield increased significantly in transgenic lines expressing LigDFG, showing the applicability of our approach. Additional new information on substrate specificity of the LigDFG enzymes is also provided
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