Institution
École Polytechnique Fédérale de Lausanne
Facility•Lausanne, Switzerland•
About: École Polytechnique Fédérale de Lausanne is a facility organization based out in Lausanne, Switzerland. It is known for research contribution in the topics: Population & Catalysis. The organization has 44041 authors who have published 98296 publications receiving 4372092 citations. The organization is also known as: EPFL & ETHL.
Topics: Population, Catalysis, Computer science, Laser, Context (language use)
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, the authors examined concentration-discharge relationships for solutes produced primarily by mineral weathering in 59 geochemically diverse US catchments and found that these catchments exhibit nearly chemostatic behaviour; their stream concentrations of weathering products such as Ca, Mg, Na, and Si typically vary by factors of only 3 to 20 while discharge varies by several orders of magnitude.
Abstract: Concentration–discharge relationships have been widely used as clues to the hydrochemical processes that control runoff chemistry. Here we examine concentration–discharge relationships for solutes produced primarily by mineral weathering in 59 geochemically diverse US catchments. We show that these catchments exhibit nearly chemostatic behaviour; their stream concentrations of weathering products such as Ca, Mg, Na, and Si typically vary by factors of only 3 to 20 while discharge varies by several orders of magnitude. Similar patterns are observed at the inter-annual time scale. This behaviour implies that solute concentrations in stream water are not determined by simple dilution of a fixed solute flux by a variable flux of water, and that rates of solute production and/or mobilization must be nearly proportional to water fluxes, both on storm and inter-annual timescales. We compared these catchments' concentration–discharge relationships to the predictions of several simple hydrological and geochemical models. Most of these models can be forced to approximately fit the observed concentration–discharge relationships, but often only by assuming unrealistic or internally inconsistent parameter values. We propose a new model that also fits the data and may be more robust. We suggest possible tests of the new model for future studies. The relative stability of concentration under widely varying discharge may help make aquatic environments habitable. It also implies that fluxes of weathering solutes in streams, and thus fluxes of alkalinity to the oceans, are determined primarily by water fluxes. Thus, hydrology may be a major driver of the ocean-alkalinity feedback regulating climate change. Copyright © 2009 John Wiley & Sons, Ltd.
620 citations
••
11 Oct 2009TL;DR: This work proposes a software router architecture that parallelizes router functionality both across multiple servers and across multiple cores within a single server, and demonstrates a 35Gbps parallel router prototype.
Abstract: We revisit the problem of scaling software routers, motivated by recent advances in server technology that enable high-speed parallel processing--a feature router workloads appear ideally suited to exploit. We propose a software router architecture that parallelizes router functionality both across multiple servers and across multiple cores within a single server. By carefully exploiting parallelism at every opportunity, we demonstrate a 35Gbps parallel router prototype; this router capacity can be linearly scaled through the use of additional servers. Our prototype router is fully programmable using the familiar Click/Linux environment and is built entirely from off-the-shelf, general-purpose server hardware.
619 citations
••
TL;DR: In this article, the reaction paths found by different methods for different nucleophiles show some striking similarities that appear to be characteristic for the reaction type, and the results of recent experimental and theoretical studies of nucleophilic addition to carbonyl groups are described.
618 citations
••
14 May 2000TL;DR: This paper shows that not only secret-key agreement satisfying the strong secrecy condition is possible, but even that the achievable key-generation rates are equal to the previous weak notions of secrecy capacity and secret- key rate.
Abstract: One of the basic problems in cryptography is the generation of a common secret key between two parties, for instance in order to communicate privately. In this paper we consider information-theoretically secure key agreement. Wyner and subsequently Csiszar and Korner described and analyzed settings for secret-key agreement based on noisy communication channels. Maurer as well as Ahlswede and Csiszar generalized these models to a scenario based on correlated randomness and public discussion. In all these settings, the secrecy capacity and the secret-key rate, respectively, have been defined as the maximal achievable rates at which a highly-secret key can be generated by the legitimate partners. However, the privacy requirements were too weak in all these definitions, requiring only the ratio between the adversary's information and the length of the key to be negligible, but hence tolerating her to obtain a possibly substantial amount of information about the resulting key in an absolute sense. We give natural stronger definitions of secrecy capacity and secret-key rate, requiring that the adversary obtains virtually no information about the entire key. We show that not only secret-key agreement satisfying the strong secrecy condition is possible, but even that the achievable key-generation rates are equal to the previous weak notions of secrecy capacity and secret-key rate. Hence the unsatisfactory old definitions can be completely replaced by the new ones. We prove these results by a generic reduction of strong to weak key agreement. The reduction makes use of extractors, which allow to keep the required amount of communication negligible as compared to the length of the resulting key.
618 citations
••
TL;DR: In this paper, a few issues related to the modeling of size effects in terms of geometrically necessary dislocations (GNDs) are critically discussed, viz. strain hardening, length scale dependence, types of GND arrays.
618 citations
Authors
Showing all 44420 results
Name | H-index | Papers | Citations |
---|---|---|---|
Michael Grätzel | 248 | 1423 | 303599 |
Ruedi Aebersold | 182 | 879 | 141881 |
Eliezer Masliah | 170 | 982 | 127818 |
Richard H. Friend | 169 | 1182 | 140032 |
G. A. Cowan | 159 | 2353 | 172594 |
Ian A. Wilson | 158 | 971 | 98221 |
Johan Auwerx | 158 | 653 | 95779 |
Menachem Elimelech | 157 | 547 | 95285 |
A. Artamonov | 150 | 1858 | 119791 |
Melody A. Swartz | 148 | 1304 | 103753 |
Henry J. Snaith | 146 | 511 | 123155 |
Kurt Wüthrich | 143 | 739 | 103253 |
Richard S. J. Frackowiak | 142 | 309 | 100726 |
Jean-Paul Kneib | 138 | 805 | 89287 |
Kevin J. Tracey | 138 | 561 | 82791 |