540 research outputs found
Book Reviews
We develop a first-principles approach based on many-body perturbation theory to investigate the effects of the interaction between electrons and carrier plasmons on the electronic properties of highly doped semiconductors and oxides. Through the evaluation of the electron self-energy, we account simultaneously for electron-plasmon and electron-phonon coupling in theoretical calculations of angle-resolved photoemission spectra, electron linewidths, and relaxation times. We apply this methodology to electron-doped anatase TiO2 as an illustrative example. The simulated spectra indicate that electron-plasmon coupling in TiO2 underpins the formation of satellites at energies comparable to those of polaronic spectral features. At variance with phonons, however, the energy of plasmons and their spectral fingerprints depends strongly on the carrier concentration, revealing a complex interplay between plasmon and phonon satellites. The electron-plasmon interaction accounts for approximately 40% of the total electron-boson interaction strength, and it is key to improve the agreement with measured quasiparticle spectra
The effect of repatriation tax costs on U.S. multinational investment
This paper investigates whether the U.S. repatriation tax for U.S. multinational corporations affects foreign investment. Our results show that the locked-out cash due to repatriation tax costs is associated with a higher likelihood of foreign (but not domestic) acquisitions. We also find a negative association between tax-induced foreign cash holdings and the market reaction to foreign deals. This result suggests that the investment activity of firms with high repatriation tax costs is viewed by the market as less value-enhancing than that of firms with low tax costs, consistent with foreign investment of firms with high repatriation tax costs possibly reflecting agency-driven behavior. Keywords: Cash; Investment; Ta
Certain minimal varieties are set-theoretic complete intersections
We present a class of homogeneous ideals which are generated by monomials and
binomials of degree two and are set-theoretic complete intersections. This
class includes certain reducible varieties of minimal degree and, in
particular, the presentation ideals of the fiber cone algebras of monomial
varieties of codimension two
Effects of isothermal oxidation on the local wear behaviour of laser cladded Inconel 625 coatings
Ni-based alloys, such as Inconel superalloys, are characterized by high strength,
excellent fabricability (including joining), and outstanding corrosion resistance.
However, their use is limited by their high cost. Ni-based coatings are used on
carbon steel components in order to increase their service life under extreme
conditions. Laser cladding deposition has emerged as an excellent method for
processing Ni-based coatings. In this work, the evolution of the local wear behaviour
of Inconel 625 laser cladded coatings after high temperature isothermal oxidation
treatments have been investigated.The authors would like to thank the Spanish government CICYT through grants
MAT2010-18916 and MAT2013-41784-R, the Universidad Rey Juan Carlos project
URJC-CM-2010-CET-5550 and the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 605207 for financial
support
iRED: A disaggregated P4-AQM fully implemented in programmable data plane hardware
Routers employ queues to temporarily hold packets when the scheduler cannot
immediately process them. Congestion occurs when the arrival rate of packets
exceeds the processing capacity, leading to increased queueing delay. Over
time, Active Queue Management (AQM) strategies have focused on directly
draining packets from queues to alleviate congestion and reduce queuing delay.
On Programmable Data Plane (PDP) hardware, AQMs traditionally reside in the
Egress pipeline due to the availability of queue delay information there. We
argue that this approach wastes the router's resources because the dropped
packet has already consumed the entire pipeline of the device. In this work, we
propose ingress Random Early Detection (iRED), a more efficient approach that
addresses the Egress drop problem. iRED is a disaggregated P4-AQM fully
implemented in programmable data plane hardware and also supports Low Latency,
Low Loss, and Scalable Throughput (L4S) framework, saving device pipeline
resources by dropping packets in the Ingress block. To evaluate iRED, we
conducted three experiments using a Tofino2 programmable switch: i) An in-depth
analysis of state-of-the-art AQMs on PDP hardware, using 12 different network
configurations varying in bandwidth, Round-Trip Time (RTT), and Maximum
Transmission Unit (MTU). The results demonstrate that iRED can significantly
reduce router resource consumption, with up to a 10x reduction in memory usage,
12x fewer processing cycles, and 8x less power consumption for the same traffic
load; ii) A performance evaluation regarding the L4S framework. The results
prove that iRED achieves fairness in bandwidth usage for different types of
traffic (classic and scalable); iii) A comprehensive analysis of the QoS in a
real setup of a DASH) technology. iRED demonstrated up to a 2.34x improvement
in FPS and a 4.77x increase in the video player buffer fill.Comment: Preprint (TNSM under review
Finite element approximation of the transport of reactive solutes in porous media .1. Error estimates for nonequilibrium adsorption processes
Published versio
GenĂłtipos de sorgo para ensilagem no norte do RS em 2012.
Editores tĂ©cnicos: Joseani Mesquita Antunes, Ana LĂdia Variani Bonato, MĂĄrcia Barrocas Moreira Pimentel
Rendimento e caracterĂsticas agronĂŽmicas de soja em sistemas de produção com integração lavoura-pecuĂĄria e diferentes manejos de solo.
bitstream/item/114975/1/2014-Documentos-online-151-p32.pd
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