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

Genótipos de sorgo para ensilagem no norte do RS em 2012.

Editores técnicos: Joseani Mesquita Antunes, Ana Lídia Variani Bonato, Márcia Barrocas Moreira Pimentel

Rendimento e características agronômicas de soja em sistemas de produção com integração lavoura-pecuária e diferentes manejos de solo.

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