9,944 research outputs found
A 35 GHz solid state transmitter/driver
Solid state transmitter/driver /multiplier/ signal source has been designed and fabricated to produce a stable crystal-controlled CW power output of 100 mw at 35 GHz
Surface Plasmon Excitation of Second Harmonic light: Emission and Absorption
We aim to clarify the role that absorption plays in nonlinear optical
processes in a variety of metallic nanostructures and show how it relates to
emission and conversion efficiency. We define a figure of merit that
establishes the structure's ability to either favor or impede second harmonic
generation. Our findings suggest that, despite the best efforts embarked upon
to enhance local fields and light coupling via plasmon excitation, nearly
always the absorbed harmonic energy far surpasses the harmonic energy emitted
in the far field. Qualitative and quantitative understanding of absorption
processes is crucial in the evaluation of practical designs of plasmonic
nanostructures for the purpose of frequency mixing
Metals used in maxillofacial surgery
The goal of maxillofacial surgery is to restore the shape and functionality of maxillofacial region. In the past years, there has been a tremendous progress in this field because of significant advances in biotechnology that provided innovative biomaterials to efficiently reconstruct the maxillofacial injured region. By using appropriate selection of the implant biomaterial, it is possible to reconstruct the native tissue, both in form and function. The ideal biomaterial should mimic native tissues regarding density, strength, and modulus of elasticity. Autografts are currently the gold standard for replacement of missing tissues, but synthetic biomaterials have been widely used because they eliminate the discomfort to take the replacement tissue from the donor site. Among synthetic biomaterials, different metals may be utilized to efficiently reconstruct the maxillofacial injured region. This article makes an effort to summarize the most important metals in use in maxillofacial surgery, and point out advantages and disadvantage of each typ
Light quark hadrons in hadronic Z decays
The results on the inclusive production of light quark hadrons in the hadronic decays of the Z are reviewed. Particular attention is paid to the new results on the inclusive production in Z -> bbbar events
Very-high-energy gamma astrophysics
High-energy photons are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the most violent phenomena in the Universe has impressively progressed
thanks to the advent of new detectors for very-high-energy Îł-rays. Ground-based detectors like the Cherenkov telescopes (H.E.S.S. and MAGIC in particular) recently
discovered more than 70 new very-high-energy sources. This article reviews the present status of very-high-energy gamma astrophysics, with emphasis on the results related to fundamental physics and on the experimental developments
Neural networks for gamma-hadron separation in MAGIC
Neural networks have proved to be versatile and robust for particle
separation in many experiments related to particle astrophysics. We apply these
techniques to separate gamma rays from hadrons for the MAGIC Cerenkov
Telescope. Two types of neural network architectures have been used for the
classi cation task: one is the MultiLayer Perceptron (MLP) based on supervised
learning, and the other is the Self-Organising Tree Algorithm (SOTA), which is
based on unsupervised learning. We propose a new architecture by combining
these two neural networks types to yield better and faster classi cation
results for our classi cation problem.Comment: 6 pages, 4 figures, to be published in the Proceedings of the 6th
International Symposium ''Frontiers of Fundamental and Computational
Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200
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